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Sample records for one-piece implant-supported superstructures

  1. Implant Gigi One-Piece vs Two-Pieces dalam Praktek Sehari-Hari

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    Dian Lestari Kurnia

    2014-12-01

    prosedur bedah dan prosedur prostetik lebih sederhana. Desain ini juga meniadakan celah mikro pada perbatasan implant dan abutment. Desain implant gigi one-piece memiliki keterbatasan pada pilihan prosedur prostetik apabila dibandingkan dengan desain implant gigi two-pieces.   One-Piece Versus Two-pieces Tooth Implant In Daily Practice. Implant had been a gold standard to replace missing tooth. However, implant marketed today was considered complex, and needs a second surgery. Complications may occur such as screw loosening or fracture and the presence of micro gap at implant-abutment-junction that is found causing fixture failure. The one-piece-implant design may offer some advantages. Purpose: this paper was aimed to discuss the pros and cons of one-piece-implants and two-piece-implants. Case 1 A 43-year-old woman came to place an implant on #16. The available bone height was 5 mm. A trans alveolar sinus lift procedure was performed with 0,5 cc allograft. A 12 mm one-piece-implant was inserted. Case 2 A 24-year-old woman came to place an implant on #46. The available bone height was 12 mm and a 10 mm two-piece-implant was inserted. Discussion: One-piece-implant offers some advantage. It needs no second surgery, easier placement protocol, and more natural prosthetic procedures. The design is preventing the failure in implant-abutment-junction failure. The absence of micro gap in one-piece-implant seems superior in preventing crestal bone resorption. However, the prosthetic option was limited in one-piece-implant. Two-piece-implant offers more choices in prosthetic abutment. Conclusion: One-piece-implant was easier and provide simple protocol with limited choice on prosthetic.

  2. Implant Gigi One-Piece Vs Two-Pieces Dalam Praktek Sehari-Hari

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    Kurnia, Dian Lestari; Ramadhani, Amilia; Hudyono, Rikko

    2014-01-01

    Saat ini, implant merupakan pilihan terbaik untuk menggantikan gigi yang tanggal, akan tetapi prosedur pemasangannya terbilang rumit dan memerlukan prosedur bedah kedua untuk pemasangan prostetik. Beberapa komplikasi seperti screw patah atau longgar dan adanya celah mikro pada batas pertemuan implant dan abutment dapat menyebabkan kegagalan implant. Studi kasus ini bertujuan untuk membahas mengenai keuntungan dan kerugian desain implant gigi one-piece dan two-pieces. Kasus pertama, seorang wa...

  3. Implant Gigi One-Piece vs Two-Pieces dalam Praktek Sehari-Hari

    OpenAIRE

    Kurnia, Dian Lestari; Ramadhani, Amilia; Hudyono, Rikko

    2014-01-01

    Saat ini, implant merupakan pilihan terbaik untuk menggantikan gigi yang tanggal, akan tetapi prosedur pemasangannya terbilang rumit dan memerlukan prosedur bedah kedua untuk pemasangan prostetik. Beberapa komplikasi seperti screw patah atau longgar dan adanya celah mikro pada batas pertemuan implant dan abutment dapat menyebabkan kegagalan implant. Studi kasus ini bertujuan untuk membahas mengenai keuntungan dan kerugian desain implant gigi one-piece dan two-pieces. Kasus pertama, seorang wa...

  4. Immediate loading of mandibular overdentures supported by one-piece, direct metal laser sintering mini-implants: a short-term prospective clinical study.

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    Mangano, Francesco G; Caprioglio, Alberto; Levrini, Luca; Farronato, Davide; Zecca, Piero A; Mangano, Carlo

    2015-02-01

    Only a few studies have dealt with immediately loaded, unsplinted mini-implants supporting ball attachment-retained mandibular overdentures (ODs). The aim of this study is to evaluate treatment outcomes of ball attachment-retained mandibular ODs supported by one-piece, unsplinted, immediately loaded, direct metal laser sintering (DMLS) mini-implants. Over a 4-year period (2009 to 2012), all patients referred to the Dental Clinic, University of Varese, and to a private practice for treatment with mandibular ODs were considered for inclusion in this study. Each patient received three or four DMLS mini-implants. Immediately after implant placement, a mandibular OD was connected to the implants. At each annual follow-up session, clinical and radiographic parameters were assessed, including the following outcome measures: 1) implant failures; 2) peri-implant marginal bone loss; and 3) complications. Statistical analysis was conducted using a life-table analysis. A total of 231 one-piece DMLS mini-implants were inserted in 62 patients. After 4 years of loading, six implants failed, giving an overall cumulative survival rate of 96.9%. The mean distance between the implant shoulder and the first visible bone-to-implant contact was 0.38 ± 0.25 and 0.62 ± 0.20 mm at the 1- and 4-year follow-up examinations, respectively. An incidence of 6.0% of biologic complications was reported; prosthetic complications were more frequent (12.9%). Within the limits of this study, it can be concluded that the immediate loading of one-piece, unsplinted, DMLS titanium mini-implants by means of ball attachment-supported mandibular ODs is a successful treatment procedure. Long-term follow-up studies are needed to confirm these results.

  5. Modified section method for laser-welding of ill-fitting cp Ti and Ni-Cr alloy one-piece cast implant-supported frameworks.

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    Tiossi, R; Falcão-Filho, H; Aguiar Júnior, F A; Rodrigues, R C; Mattos, M da G; Ribeiro, R F

    2010-05-01

    This study aimed to verify the effect of modified section method and laser-welding on the accuracy of fit of ill-fitting commercially pure titanium (cp Ti) and Ni-Cr alloy one-piece cast frameworks. Two sets of similar implant-supported frameworks were constructed. Both groups of six 3-unit implant-supported fixed partial dentures were cast as one-piece [I: Ni-Cr (control) and II: cp Ti] and evaluated for passive fitting in an optical microscope with both screws tightened and with only one screw tightened. All frameworks were then sectioned in the diagonal axis at the pontic region (III: Ni-Cr and IV: cp Ti). Sectioned frameworks were positioned in the matrix (10-Ncm torque) and laser-welded. Passive fitting was evaluated for the second time. Data were submitted to anova and Tukey-Kramer honestly significant difference tests (P screws tightened, one-piece cp Ti group II showed significantly higher misfit values (27.57 +/- 5.06 microm) than other groups (I: 11.19 +/- 2.54 microm, III: 12.88 +/- 2.93 microm, IV: 13.77 +/- 1.51 microm) (P screw-tightened test, with readings on the opposite side to the tightened side, Ni-Cr cast as one-piece (I: 58.66 +/- 14.30 microm) was significantly different from cp Ti group after diagonal section (IV: 27.51 +/- 8.28 microm) (P 0.05). Results showed that diagonally sectioning ill-fitting cp Ti frameworks lowers misfit levels of prosthetic implant-supported frameworks and also improves passivity levels of the same frameworks when compared to one-piece cast structures.

  6. Biomechanical evaluation of one-piece and two-piece small-diameter dental implants: In-vitro experimental and three-dimensional finite element analyses.

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    Wu, Aaron Yu-Jen; Hsu, Jui-Ting; Chee, Winston; Lin, Yun-Te; Fuh, Lih-Jyh; Huang, Heng-Li

    2016-09-01

    Small-diameter dental implants are associated with a higher risk of implant failure. This study used both three-dimensional finite-element (FE) simulations and in-vitro experimental tests to analyze the stresses and strains in both the implant and the surrounding bone when using one-piece (NobelDirect) and two-piece (NobelReplace) small-diameter implants, with the aim of understanding the underlying biomechanical mechanisms. Six experimental artificial jawbone models and two FE models were prepared for one-piece and two-piece 3.5-mm diameter implants. Rosette strain gauges were used for in-vitro tests, with peak values of the principal bone strain recorded with a data acquisition system. Implant stability as quantified by Periotest values (PTV) were also recorded for both types of implants. Experimental data were analyzed statistically using Wilcoxon's rank-sum test. In FE simulations, the peak value and distribution of von-Mises stresses in the implant and bone were selected for evaluation. In in-vitro tests, the peak bone strain was 42% lower for two-piece implants than for one-piece implants. The PTV was slightly lower for one-piece implants (PTV = -6) than for two-piece implants (PTV = -5). In FE simulations, the stresses in the bone and implant were about 23% higher and 12% lower, respectively, for one-piece implants than those for two-piece implants. Due to the higher peri-implant bone stresses and strains, one-piece implants (NobelDirect) might be not suitable for use as small-diameter implants. Copyright © 2016. Published by Elsevier B.V.

  7. One-Piece Implant-Retained Mandibular Overdentures By Pre-Fabricated Titanium Telescopic Attachments and Frictional Varnish: A Two-Year Prospective Study.

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    Nik, Shahram Namjoy; Nejatian, Touraj

    2016-12-01

    Clinical efficiency of one-piece screw-type implants with telescopic were attachments evaluated in this study. Twenty-four patients received a mandibular implant-supported overdenture and maxillary complete denture. Ninety-six one-piece implants were inserted in the inter-foraminal area. Implants were immediately loaded with an implant-retained overdenture and telescopic attachments which had frictional retention elements. There was 0.25±0.24 mm, 0.32±0.25 mm, 0.43±0.30 mm, 0.61±0.30 mm and of bone resorption after 3, 6, 12 and 24 months, respectively. The need to activate the frictional retention was the most common complication. Treatment outcomes for prefabricated telescopic retained overdentures on one-piece implants are similar to that obtained in cases of delayed loading. Copyright© 2016 Dennis Barber Ltd.

  8. Bite Reconstruction in the Aesthetic Zone Using One-Piece Bicortical Screw Implants

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    Stefan Ihde

    2018-01-01

    Full Text Available The aim of this article was to present the clinical application of a new, smooth surfaced one-piece bicortical screw implant with immediate loading protocol. An 18-year-old, healthy male patient with a history of total dislocation and replantation of teeth 11 and 21 in early childhood was admitted to the clinic. Teeth 11 and 21 were extracted, and two long one-piece implants were inserted at extraction sockets in one surgical session under local anesthesia. Temporary composite crowns were placed in the patient on the same day. After 3 months, the single-phase two-layer impression was made and the composite crowns were replaced with metal-ceramic crowns. After 12 months, satisfactory aesthetic and functional results were obtained.

  9. One-Piece Zirconia Ceramic versus Titanium Implants in the Jaw and Femur of a Sheep Model: A Pilot Study.

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    Siddiqi, A; Duncan, W J; De Silva, R K; Zafar, S

    2016-01-01

    Reports have documented titanium (Ti) hypersensitivity after dental implant treatment. Alternative materials have been suggested including zirconia (Zr) ceramics, which have shown predictable osseointegration in animal studies and appear free of immune responses. The aim of the research was to investigate the bone-to-implant contact (BIC) of one-piece Zr, compared with one-piece Ti implants, placed in the jaws and femurs of domestic sheep. Ten New Zealand mixed breed sheep were used. A One-piece prototype Ti (control) and one Zr (test) implant were placed in the mandible, and one of each implant (Ti and Zr) was placed into the femoral epicondyle of each animal. The femur implants were submerged and unloaded; the mandibular implants were placed using a one-stage transgingival protocol and were nonsubmerged. After a healing period of 12 weeks, %BIC was measured. The overall survival rate for mandibular and femur implants combined was 87.5%. %BIC was higher for Zr implants versus Ti implants in the femur (85.5%, versus 78.9%) ( p = 0.002). Zirconia implants in the mandible showed comparable %BIC to titanium implants (72.2%, versus 60.3%) ( p = 0.087). High failure rate of both Zr and Ti one-piece implants in the jaw could be attributed to the one-piece design and surface characteristics of the implant that could have influenced osseointegration. Further clinical trials are recommended to evaluate the performance of zirconia implants under loading conditions.

  10. Immediate loading with single-piece implant following extraction

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    Hemlata Dwivedi

    2017-01-01

    Full Text Available Although dental implantology had evolved over a number of years, many dental surgeons are unaware of the concept of immediate loading with the use of one-piece implant that began in the early 1960s. The goal of successful prosthodontics rehabilitation is to provide function, esthetics, and comfort to the patient. The aim of this literature is to provide an overview of one-piece implant, with its advantages and disadvantages over conventional two-piece implant. Immediate prosthetic of a one-piece system allows for a better tissue healing and better adhesion of gingival mucosa to form a collar which is healthy and adherent to the implant, avoiding a second surgical procedure, and also includes a very important aspect esthetics. This article describes a case report of immediate loading with single-piece implant following extraction.

  11. Immediate prostheses on one-piece trans-mucosal implants in flapless surgical procedures Case Series Report. Part I: full arch rehabilitations

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    Aris Petros Tripodakis

    2012-06-01

    Full Text Available Aim: The aim of the present case series report is to illustrate a clinical technique and present the application of onepiece transmucosal implants in flapless surgical procedures, supporting full arch immediate prostheses. Materials and methods: A total of 294 implants (Xive TG, Friadent, Germany have been used to support full arch immediate prostheses, over the last six years and have been in function for at least one year. The surgical placement of five or more implants per case involved immediate extraction and intrasocket flapless placement, combined with minimal flap elevation in the areas of healed extraction sites (43 mandibular and 7 maxillary arches. In all cases immediate provisionalization followed. Detailed three-dimensional cone-beam localized volumetric tomography preceeded the surgical procedures. The delivery of the final ceramo-metal prostheses was accomplished within a 20 day period. Materials and methods: Results Six implants failed to osseointegrate. All other implants are still successfully bearing the final prosthesis for the time that they have been followed. Soft tissue reaction was favorable from both the biologic and esthetic point of view. Conclusion: The flapless placement of one piece implants into edentulous healed sites is a predictable procedure in the presence of abundance of supporting bone as confirmed by 3-D imaging. On the other hand, immediate extraction placement of one piece implants allows the engagement of sound bone located deeper into the socket and provides adequate mechanical support of the soft tissue architecture that is preserved predictably. In all cases the prosthetic procedures are accomplished without disturbing the hardsoft tissue interface as the abutment-prosthesis interface is coronally elevated by the virtual design of the implant.

  12. Improving the fit of implant prosthetics: an in vitro study.

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    Yannikakis, Stavros; Prombonas, Anthony

    2013-01-01

    Accurate and passive fit between a prosthesis and its supporting implants has been considered a prerequisite for successful long-term osseointegration. The objective of this in vitro study was to evaluate the strain development during tightening of a five-unit screw-retained superstructure constructed using five different methods. Five-unit screw-retained fixed partial prostheses (n = 25) were fabricated on three implants embedded in an epoxy resin block using five different methods: (1) cobalt-chromium (Co-Cr), plastic cylinders, one-piece cast; (2) Co-Cr, plastic cylinders, framework sectioned, preceramic laser-welding soldering; (3) gold-platinum (Au-Pt), gold cylinders, one-piece cast; (4) Au-Pt, gold cylinders, framework sectioned, preceramic laser-welding soldering; (5) Co-Cr, one-piece cast, and cementation to "passive abutments" (Southern Implants) after final finishing and polishing. Strain gauges (SG) were attached to the fixed partial prosthesis (FPP) and to the resin block to measure the stress created during screw tightening. The combination of Co-Cr alloy and plastic cylinders in a one-piece cast showed such an inadequate fit among the fabricated methods that this group was excluded from the remainder of the experiment. Specimens of Au-Pt cast on gold cylinders in one piece showed higher strain development than the other groups used in this study, with strains ranging from 223.1 to 2,198.1 Μm/m. Sectioning and soldering significantly improved the overall fit. FPPs of Co-Cr in a one-piece cast cemented to "passive abutments" produced the best level of fit, with the least strain development in the prosthesis and the resin block (59 to 204.6 Μm/m). Absolute fit of superstructures on implants is not possible using conventional laboratory procedures. Cementing FPPs onto prefabricated cylinders directly onto the implants significantly reduces strain development compared to the other fabrication methods.

  13. Torque Removal Evaluation of Screw in One-Piece and Two-Piece Abutments Tightened with a Handheld screwdriver

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    Jalil Ghanbarzadeh

    2013-12-01

    Full Text Available Introduction: Some clinicians use a handheld screw driver instead of a torque wrench to definitively tighten abutment screws. The aim of this study was to compare the removal torque of one-piece and two-piece abutments tightened with a handheld driver and a torque control ratchet. Methods: 40 ITI implants were placed in acrylic blocks and divided into 4 groups. In groups one and two, 10 ITI one-piece abutments (Solid® and in groups three and four, 10 ITI two-piece abutments (Synocta® were placed on the implants. In groups one and three abutments were tightened by 5 experienced males and 5 experienced females using a handheld driver. In groups two and four abutments were tightened using a torque wrench with torque values of 10, 20 and 35 N.cm. Insertion torque and removal torque values of the abutments were measured with a digital torque meter. Results: The insertion torque values (ITVs of males in both abutments were significantly higher than those of females. ITVs in both Solid® and Synocta® abutments tightened with a handheld screwdriver were similar to the torque of 20 N.cm in the torque wrench. Removal torque values (RTVs of solid® abutments were higher than those of synocta® abutments. Conclusion: The one- piece abutments (solid® showed higher RTVs than the two-piece abutments (synocta®. Hand driver does not produce sufficient preload force for the final tightening of the abutment

  14. Prosthetic misfit of implant-supported prosthesis obtained by an alternative section method

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    Falcão-Filho, Hilmo Barreto Leite; de Aguiar, Fábio Afrânio; Rodrigues, Renata Cristina Silveira; de Mattos, Maria da Gloria Chiarello; Ribeiro, Ricardo Faria

    2012-01-01

    PURPOSE Adequate passive-fitting of one-piece cast 3-element implant-supported frameworks is hard to achieve. This short communication aims to present an alternative method for section of one-piece cast frameworks and for casting implant-supported frameworks. MATERIALS AND METHODS Three-unit implant-supported nickel-chromium (Ni-Cr) frameworks were tested for vertical misfit (n = 6). The frameworks were cast as one-piece (Group A) and later transversally sectioned through a diagonal axis (Group B) and compared to frameworks that were cast diagonally separated (Group C). All separated frameworks were laser welded. Only one side of the frameworks was screwed. RESULTS The results on the tightened side were significantly lower in Group C (6.43 ± 3.24 µm) when compared to Groups A (16.50 ± 7.55 µm) and B (16.27 ± 1.71 µm) (Plaser welding showed significant improvement in the levels of misfit of the frameworks (Group A, 58.66±14.30 µm; Group B, 39.48±12.03 µm; Group C, 23.13±8.24 µm) (P<.05). CONCLUSION Casting diagonally sectioned frameworks lowers the misfit levels. Lower misfit levels for the frameworks can be achieved by diagonally sectioning one-piece frameworks. PMID:22737313

  15. Prevention of Cutaneous Tissue Contracture During Removal of Craniofacial Implant Superstructures for CT and MRI Studies

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    Maureen Sullivan

    2010-04-01

    Full Text Available Objectives: Head and neck cancer patients who have lost facial parts following surgical intervention frequently require craniofacial implant retained facial prostheses for restoration. Many craniofacial implant patients require computed tomography and magnetic resonance imaging scans as part of their long-term follow-up care. Consequently removal of implant superstructures and peri-abutment tissue management is required for those studies. The purpose of the present paper was to describe a method for eliminating cranial imaging artifacts in patients with craniofacial implants.Material and Methods: Three patients wearing extraoral implant retained facial prostheses needing either computed tomography or magnetic resonance imaging studies were discussed. Peri-implant soft tissues contracture after removal of percutaneous craniofacial implant abutments during computed tomography and magnetic resonance imaging studies was prevented using a method proposed by authors. The procedure involves temporary removal of the supra-implant components prior to imaging and filling of the tissue openings with polyvinyl siloxane dental impression material.Results: Immediately after filling of the tissue openings with polyvinyl siloxane dental impression material patients were sent for the imaging studies, and were asked to return for removal of the silicone plugs and reconnection of all superstructure hardware after imaging procedures were complete. The silicone plugs were easily removed with a dental explorer. The percutaneous abutments were immediately replaced and screwed into the implants which were at the bone level.Conclusions: Presented herein method eliminates the source of artifacts and prevents contracture of percutaneous tissues upon removal of the implant abutments during imaging.

  16. Fit Analysis of Different Framework Fabrication Techniques for Implant-Supported Partial Prostheses.

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    Spazzin, Aloísio Oro; Bacchi, Atais; Trevisani, Alexandre; Farina, Ana Paula; Dos Santos, Mateus Bertolini

    2016-01-01

    This study evaluated the vertical misfit of implant-supported frameworks made using different techniques to obtain passive fit. Thirty three-unit fixed partial dentures were fabricated in cobalt-chromium alloy (n = 10) using three fabrication methods: one-piece casting, framework cemented on prepared abutments, and laser welding. The vertical misfit between the frameworks and the abutments was evaluated with an optical microscope using the single-screw test. Data were analyzed using one-way analysis of variance and Tukey test (α = .05). The one-piece casted frameworks presented significantly higher vertical misfit values than those found for framework cemented on prepared abutments and laser welding techniques (P Laser welding and framework cemented on prepared abutments are effective techniques to improve the adaptation of three-unit implant-supported prostheses. These techniques presented similar fit.

  17. Alveolar Bone Resorption Evaluation Around Single-piece Designed Bicortical Implants, Using Immediate Loading Protocol, Based on Orthopantomographs

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    Száva Dániel-Tamás

    2017-12-01

    Full Text Available Background: Inserting dental implants in severely atrophied jawbones is a great challenge for the dental practitioner. There are an increasing number of patients who choose dental implantanchored prosthetic restorations despite compromised bone quality and quantity. There have been numerous attempts in adapting implant design for the atrophic crestal bone. One-piece, needle-type basal implant design is a typical design for these cases. These implants are inserted in the remaining compact bone located in the basal aspect of the jawbones. If high primary stability is achieved, these implants are used for immediate loading protocol. From many points of view, this technique is based on contradictory principles compared to classic implant surgery and loading protocols. The aim of this study was to investigate the long-term success of basal one-piece short-diameter dental implants used for immediate loading protocol.

  18. Clinical Performance of One-Piece, Screw-Retained Implant Crowns Based on Hand-Veneered CAD/CAM Zirconia Abutments After a Mean Follow-up Period of 2.3 Years.

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    Schnider, Nicole; Forrer, Fiona Alena; Brägger, Urs; Hicklin, Stefan Paul

    The aim of this study was to evaluate the clinical performance of one-piece, screw-retained implant crowns based on hand-veneered computer-aided design/computer-aided manufacture (CAD/CAM) zirconium dioxide abutments with a crossfit connection at least 1 year after insertion of the crown. Consecutive patients who had received at least one Straumann bone level implant and one-piece, screw-retained implant crowns fabricated with CARES zirconium dioxide abutments were reexamined. Patient satisfaction, occlusal and peri-implant parameters, mechanical and biologic complications, radiologic parameters, and esthetics were recorded. A total of 50 implant crowns in the anterior and premolar region were examined in 41 patients. The follow-up period of the definitive reconstructions ranged from 1.1 to 3.8 years. No technical and no biologic complications had occurred. At the reexamination, 100% of the implants and reconstructions were in situ. Radiographic evaluation revealed a mean distance from the implant shoulder to the first visible bone-to-implant contact of 0.06 mm at the follow-up examination. Screw-retained crowns based on veneered CAD/CAM zirconium dioxide abutments with a crossfit connection seem to be a promising way to replace missing teeth in the anterior and premolar region. In the short term, neither failures of components nor complications were noted, and the clinical and radiographic data revealed stable hard and soft tissue conditions.

  19. An alternative section method for casting and posterior laser welding of metallic frameworks for an implant-supported prosthesis.

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    de Aguiar, Fábio Afrânio; Tiossi, Rodrigo; Rodrigues, Renata Cristina Silveira; Mattos, Maria de Gloria Chiarello; Ribeiro, Ricardo Faria

    2009-04-01

    The aim of this study was to compare the accuracy of fit of three types of implant-supported frameworks cast in Ni-Cr alloy: specifically, a framework cast as one piece compared to frameworks cast separately in sections to the transverse or the diagonal axis, and later laser welded. Three sets of similar implant-supported frameworks were constructed. The first group of six 3-unit implant-supported frameworks were cast as one piece, the second group of six were sectioned in the transverse axis of the pontic region prior to casting, and the last group of six were sectioned in the diagonal axis of the pontic region prior to casting. The sectioned frameworks were positioned in the matrix (10 N.cm torque) and laser welded. To evaluate passive fit, readings were made with an optical microscope with both screws tightened and with only one-screw tightened. Data were submitted to ANOVA and Tukey-Kramer's test (p screws were tightened, no differences were found between the three groups (p > 0.05). In the single-screw-tightened test, with readings made opposite to the tightened side, the group cast as one piece (57.02 +/- 33.48 mum) was significantly different (p 0.05) from the group transversally sectioned (31.42 +/- 20.68 microm). On the tightened side, no significant differences were found between the groups (p > 0.05). Results of this study showed that casting diagonally sectioned frameworks lowers misfit levels of prosthetic implant-supported frameworks and also improves the levels of passivity to the same frameworks when compared to structures cast as one piece.

  20. Titanium versus zirconia implants supporting maxillary overdentures: three-dimensional finite element analysis.

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    Osman, Reham B; Elkhadem, Amr H; Ma, Sunyoung; Swain, Michael V

    2013-01-01

    The purpose of this study was to compare the stress and strain occurring in peri-implant bone and implants used to support maxillary overdentures. Three-dimensional finite element analysis (3D FEA) was used to compare one-piece zirconia and titanium implants. Two types of implants were simulated using a 3D FEA model: one-piece zirconia and titanium implants (diameter, 3.8 × 11.5 mm) with 2.25-mm diameter ball abutments. In each simulation four implants were placed bilaterally in the canine/premolar region of an edentulous maxillary model. Static loads were applied axially and 20 degrees buccolingually on the buccal slope of the lingual cusps of posterior teeth of the first quadrant. Von Mises stresses and equivalent strains generated in peri-implant bone and first principal stresses in the implants were calculated. Comparable stress and strain values were shown in the peri-implant bone for both types of implants. The maximum equivalent strain produced in the peri-implant region was mostly within the range for bone augmentation. Under oblique loading, maximum von Mises stresses and equivalent strain were more evident at the neck of the most distal implant on the loaded side. Under axial load, the stress and strain were transferred to the peri-implant bone around the apex of the implant. Maximum tensile stresses that developed for either material were well below their fracture strength. The highest stresses were mainly located at the distobuccal region of the neck for the two implant materials under both loading conditions. From a biomechanical point of view, ceramic implants made from yttrium-stabilized tetragonal polycrystalline zirconia may be a potential alternative to conventional titanium implants for the support of overdentures. This is particularly relevant for a select group of patients with a proven allergy to titanium. Prospective clinical studies are still required to confirm these in vitro results. Different simulations presenting various cortical bone

  1. In vitro synchrotron-based radiography of micro-gap formation at the implant-abutment interface of two-piece dental implants.

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    Rack, A; Rack, T; Stiller, M; Riesemeier, H; Zabler, S; Nelson, K

    2010-03-01

    Micro-gap formation at the implant-abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites.

  2. Integral ceramic superstructure evaluation using time domain optical coherence tomography

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    Sinescu, Cosmin; Bradu, Adrian; Topala, Florin I.; Negrutiu, Meda Lavinia; Duma, Virgil-Florin; Podoleanu, Adrian G.

    2014-02-01

    Optical Coherence Tomography (OCT) is a non-invasive low coherence interferometry technique that includes several technologies (and the corresponding devices and components), such as illumination and detection, interferometry, scanning, adaptive optics, microscopy and endoscopy. From its large area of applications, we consider in this paper a critical aspect in dentistry - to be investigated with a Time Domain (TD) OCT system. The clinical situation of an edentulous mandible is considered; it can be solved by inserting 2 to 6 implants. On these implants a mesostructure will be manufactured and on it a superstructure is needed. This superstructure can be integral ceramic; in this case materials defects could be trapped inside the ceramic layers and those defects could lead to fractures of the entire superstructure. In this paper we demonstrate that a TD-OCT imaging system has the potential to properly evaluate the presence of the defects inside the ceramic layers and those defects can be fixed before inserting the prosthesis inside the oral cavity. Three integral ceramic superstructures were developed by using a CAD/CAM technology. After the milling, the ceramic layers were applied on the core. All the three samples were evaluated by a TD-OCT system working at 1300 nm. For two of the superstructures evaluated, no defects were found in the most stressed areas. The third superstructure presented four ceramic defects in the mentioned areas. Because of those defects the superstructure may fracture. The integral ceramic prosthesis was send back to the dental laboratory to fix the problems related to the material defects found. Thus, TD-OCT proved to be a valuable method for diagnosing the ceramic defects inside the integral ceramic superstructures in order to prevent fractures at this level.

  3. One-year results of maxillary overdentures supported by 2 titanium-zirconium implants - implant survival rates and radiographic outcomes.

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    Zembic, Anja; Tahmaseb, Ali; Jung, Ronald E; Wismeijer, Daniel

    2017-07-01

    To assess implant survival rates and peri-implant bone loss of 2 titanium-zirconium implants supporting maxillary overdentures at 1 year of loading. Twenty maxillary edentulous patients (5 women and 15 men) being dissatisfied with their complete dentures were included. In total, 40 diameter-reduced titanium-zirconium implants were placed in the anterior maxilla. Local guided bone regeneration (GBR) was allowed if the treatment did not compromise implant stability. Following 3 to 5 months of healing, implant-supported overdentures were inserted on two ball anchors. Implants and overdentures were assessed at 1, 2, 4, and 8 weeks after implant insertion and 2, 4, and 12 months after insertion of overdentures (baseline). Standardized radiographs were taken at implant loading and 1 year. Implant survival rates and bone loss were the primary outcomes. Nineteen patients (1 dropout) with 38 implants were evaluated at a mean follow-up of 1.1 years (range 1.0-1.7 years). One implant failed resulting in an implant survival rate of 97.3%. There was a significant peri-implant bone loss of the implants at 1 year of function (mean, 0.7 mm, SD = 1.1 mm; median: 0.48 mm, IQR = 0.56 mm). There was a high 1-year implant survival rate for edentulous patients receiving 2 maxillary implants and ball anchors as overdenture support. However, several implants exhibited an increased amount of bone loss of more than 2 mm. Overdentures supported by 2 maxillary implants should thus be used with caution as minimally invasive treatment for specific patients encountering problems with their upper dentures until more long-term data is available. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Learning and Memory Processes Following Cochlear Implantation:The Missing Piece of the Puzzle

    Directory of Open Access Journals (Sweden)

    David B. Pisoni

    2016-04-01

    Full Text Available At the present time, there is no question that cochlear implants work and often work very well in quiet listening conditions for many profoundly deaf children and adults. The speech and language outcomes data published over the last two decades document quite extensively the clinically significant benefits of cochlear implants. Although there now is a large body of evidence supporting the efficacy of cochlear implants as a medical intervention for profound hearing loss in both children and adults, there still remain a number of challenging unresolved clinical and theoretical issues that deal with the effectiveness of cochlear implants in individual patients that have not yet been successfully resolved. In this paper, we review recent findings on learning and memory, two central topics in the field of cognition that have been seriously neglected in research on cochlear implants. Our research findings on sequence learning, memory and organization processes, and retrieval strategies used in verbal learning and memory of categorized word lists suggests that basic domain-general learning abilities may be the missing piece of the puzzle in terms of understanding the cognitive factors that underlie the enormous individual differences and variability routinely observed in speech and language outcomes following cochlear implantation.

  5. Two-piece impression procedure for implant-retained orbital prostheses.

    Science.gov (United States)

    Ozcelik, Tuncer Burak; Yilmaz, Burak

    2012-01-01

    Obtaining an accurate impression of facial tissues with undercuts and extraoral implants has always been a challenge for both clinicians and patients. This report describes a three-step, two-piece technique that enables an accurate and comfortable impression of undercut tissues and extraoral implants in an orbital defect. An impression of the basal tissue surface of the defect area was made using a medium-body polyether impression material followed by an impression of the entire face of the patient made with a polyvinyl siloxane (PVS) impression material. First, the PVS impression material was removed; second, the impression posts were removed from the magnets; and third, the polyether impression was removed from the defect. The impression posts were attached to the implant analogs and placed in the negative spaces in the polyether impression. The polyether impression, which carries the implant analogs and impression posts, was placed in the PVS impression through the negative spaces. This technique minimizes trauma to the soft tissues and implants during impression making and also does not require additional materials.

  6. FEA and microstructure characterization of a one-piece Y-TZP abutment.

    Science.gov (United States)

    da Silva, Lucas Hian; Ribeiro, Sebastião; Borges, Alexandre Luís Souto; Cesar, Paulo Francisco; Tango, Rubens Nisie

    2014-11-01

    The most important drawback of dental implant/abutment assemblies is the need for a fixing screw. This study aimed to develop an esthetic one-piece Y-TZP abutment to suppress the use of the screw. Material characterization was performed using a bar-shaped specimen obtained by slip-casting to validate the method prior to prototype abutment fabrication by the same process. The mechanical behavior of the prototype abutment was verified and compared with a conventional abutment by finite element analysis (FEA). The abutment was evaluated by micro-CT analysis and its density was measured. FEA showed stress concentration at the first thread pitch during installation and in the cervical region during oblique loading for both abutments. However, stress concentration was observed at the base of the screw head and stem in the conventional abutment. The relative density for the fabricated abutment was 95.68%. Micro-CT analysis revealed the presence of elongated cracks with sharp edges over the surface and porosity in the central region. In the light of these findings, the behavior of a one-piece abutment is expected to be better than that of the conventional model. New studies should be conducted to clarify the performance and longevity of this one-piece Y-TZP abutment. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  7. Immediate implant-supported oral rehabilitation using a photocurable plastic skull model and laser welding. A technical note on the screw-retained type: Part 1.

    Science.gov (United States)

    Tomotake, Yoritoki; Ishida, Osamu; Kanitani, Hideo; Ichikawa, Tetsuo

    2002-01-01

    This article describes a new procedure for immediate implant-supported oral rehabilitation using a photocurable resin skull model and a laser-welding apparatus. Preoperatively, the framework was fabricated on a photocurable resin skull model produced from a CT scan and individually designed guide template. The implants were immediately placed using the guide template; laser welding connected the components of framework. Despite the custom-made prosthesis, the total treatment from implant placement to superstructure placement can be completed within only 1 day. This procedure for immediate implant-supported oral rehabilitation using a photocurable resin skull model and a laser-welding apparatus may be useful for any implant system and patient.

  8. Toolbox for super-structured and super-structure free multi-disciplinary building spatial design optimisation

    NARCIS (Netherlands)

    Boonstra, S.; van der Blom, K.; Hofmeyer, H.; Emmerich, M.T.M.; van Schijndel, A.W.M.; de Wilde, P.

    2018-01-01

    Multi-disciplinary optimisation of building spatial designs is characterised by large solution spaces. Here two approaches are introduced, one being super-structured and the other super-structure free. Both are different in nature and perform differently for large solution spaces and each requires

  9. The stereognostic ability of natural dentitions versus implant-supported fixed prostheses or overdentures.

    Science.gov (United States)

    Jacobs, R; Bou Serhal, C; van Steenberghe, D

    1997-06-01

    A stereognostic ability test was performed in 60 patients. Forty patients were rehabilitated by means of osseointegrated implants. One group consisted of 20 patients with fixed prostheses on implants in both the upper and lower jaws. The other 20 patients had a maxillary denture while in the mandible an overdenture was retained by means of two implants connected by a bar. They were compared to a group of 20 subjects (controls) with a non-restored natural dentition. For the stereognostic ability test, subjects had to recognise ten different test pieces by manipulating them with two antagonistic incisor teeth, avoiding any contact with other oral structures. Both response time and percentage accuracy of recognition were evaluated. The present findings indicated that subjects with an overdenture on implants did not score significantly different from those with an implant-supported fixed prosthesis. In contrast, subjects with teeth had a significantly better stereognostic ability. The percentage of correct responses was 52% for overdentures, 56% for fixed prostheses on implants and 75% for natural dentitions. From these results, it could be concluded that the stereognostic ability is impaired in subjects rehabilitated with osseointegrated implants by about one-third to one-quarter compared to subjects with natural teeth.

  10. Placement of implant bridge anterior maxilla post autograft (Serial case

    Directory of Open Access Journals (Sweden)

    Rifaat Nurrahma

    2016-06-01

    Full Text Available An advanced technology with implants based has now been developed in recent years.Implant with the bridge superstructure method is employed after variety of considerations where it is expected to meet its function, aesthetics, and comfortability.The alveolar bone existed is one reason for the process of adding bone (bonegraft.This case report proposes to determine the successful insertion of a superstructure anterior implant bridge post autograft.Two female patients were asked to use dental implant anterior with bridge system.The first case, the autograft application is made for a 20-year-old woman with edentulous teeth 11, 21, 22. One year later it was then inserted in the area of dental implant fixture 11 and 22. After 9 months, the healing abutments and the superstructure were inserted too.2 weeks after, the abutments of bridge and crowns of teeth 11, 21 and 22 with a pontic in the teeth 21 had been inserted. The second case, a 46-year-old woman with edentulous 11,12,21,22.They want to change the denture because they did not feel comfortable with the removable denture acrylic.Fixture placement was done a year after autograft.Insertion of healing abutments and the superstructure printing can be done after 6 months.A month later implant abutments and crowns could be inserted.Labial fullness is corrected; an implant-retained in the region of 12 and 21, 12, and 22 used the pontic.Prosthodontic rehabilitation with a fixed denture using the implant bridge after autograft anterior maxilla is an alternative fixed denture placement with satisfactory results, aesthetic correction and comfortably.

  11. Stability of prototype two-piece zirconia and titanium implants after artificial aging: an in vitro pilot study.

    Science.gov (United States)

    Kohal, Ralf-Joachim; Finke, Hans Christian; Klaus, Gerold

    2009-12-01

    Zirconia oral implants are a new topic in implant dentistry. So far, no data are available on the biomechanical behavior of two-piece zirconia implants. Therefore, the purpose of this pilot investigation was to test in vitro the fracture strength of two-piece cylindrical zirconia implants after aging in a chewing simulator. This laboratory in vitro investigation comprised three different treatment groups. Each group consisted of 16 specimens. In group 1, two-piece zirconia implants were restored with zirconia crowns (zirconia copings veneered with Triceram; Esprident, Ispringen, Germany), and in group 2 zirconia implants received Empress 2 single crowns (Ivoclar Vivadent AG, Schaan, Liechtenstein). The implants, including the abutments, in the two zirconia groups were identical. In group 3, similar titanium implants were reconstructed with porcelain-fused-to-metal crowns. Eight samples of each group were submitted to artificial aging with a long-term load test in the artificial mouth (chewing simulator). Subsequently, all not artificially aged samples and all artificially aged samples that survived the long-term loading of each group were submitted to a fracture strength test in a universal testing machine. For the pairwise comparisons in the different test groups with or without artificial loading and between the different groups at a given artificial loading condition, the Wilcoxon rank-sum test for independent samples was used. The significance level was set at 5%. One sample of group 1 (veneer fracture), none of group 2, and six samples of group 3 (implant abutment screw fractures) failed while exposed to the artificial mouth. The values for the fracture strength after artificial loading with 1.2 million cycles for group 1 were between 45 and 377 N (mean: 275.7 N), in group 2 between 240 and 314 N (mean: 280.7 N), and in the titanium group between 45 and 582 N (mean: 165.7 N). The fracture strength results without artificial load for group 1 amounted to between

  12. Dynamic cholesteric liquid crystal superstructures photoaligned by one-step polarization holography

    Science.gov (United States)

    Li, Sen-Sen; Shen, Yuan; Chang, Zhen-Ni; Li, Wen-Song; Xu, Yan-Chao; Fan, Xing-Yu; Chen, Lu-Jian

    2017-12-01

    A convenient approach to modulate the fingerprint textures of methyl red (MR) doped cholesteric liquid crystals by asymmetric photoalignment in the green-light waveband is presented, resulting in the generation of voltage-controllable helical superstructures. The interaction between the MR molecules and the incident light polarization determines the initial twisted planar geometry, providing a multivariant control over the stripe directions of fingerprint textures by applying a proper electric field. The key factors for precise manipulation of fingerprint stripes in a predictable and rewritable manner are analyzed theoretically and investigated experimentally, which involves the alignment asymmetry, the ratio of cell gap to natural pitch length, and the chirality of chiral dopant. Dynamic periodic fingerprint textures in shapes of dashed curve and dashed line are further demonstrated by utilizing a facile one-step polarization holography process using two beams with orthogonal circular and orthogonal linear polarizations, respectively. It is believed that the practical approach described in this study would enrich the research contents of self-assembled hierarchical superstructures using soft liquid crystal building blocks.

  13. Rehabilitation of Posterior Maxilla with Obturator Supported by Zygomatic Implants

    Directory of Open Access Journals (Sweden)

    Sankalp Mittal

    2018-01-01

    Full Text Available Prosthetic rehabilitation of atrophic maxilla and large maxillary defects can be done successfully by zygomatic implant-supported prosthesis. Zygomatic implants are an avant-garde to complex and invasive-free vascularised osteocutaneous flaps, distraction osteogenesis, and the solution to flap failures. A treated case of tuberculous osteomyelitis, with a class II (Aramany’s classification maxillary defect, reported to oral maxillofacial department, Government Dental College (RUHS-CODS. The defect in this group was unilateral, retaining the anterior teeth. The patient was previously rehabilitated with a removable maxillary obturator. Inadequate retention affected essential functions like speaking, mastication, swallowing, esthetics, and so on due to lack of sufficient supporting tissues. A fixed prosthetic rehabilitation of posterior maxillary defect was done with obturator supported with two single-piece zygomatic implants. At 1-year follow-up, the patient was comfortable with the prosthesis, and no further complaints were recorded.

  14. Terminal Posterior Tilted Implants Planned as a Sinus Graft Alternative for Fixed Full-Arch Implant-Supported Maxillary Restoration: A Case Series with 10- to 19-Year Results on 44 Consecutive Patients Presenting for Routine Maintenance.

    Science.gov (United States)

    Fortin, Yvan; Sullivan, Richard M

    2017-02-01

    Posterior maxillary tilted implants are gaining prevalence as an alternative to sinus grafts supporting fixed maxillary restorations. This paper reports long-term results after loading using this technique. Consecutive patients presenting for either routine hygiene maintenance or unplanned emergency care who had received tilted implants as a sinus graft alternative to support fixed fully implant-supported restoration of an edentulous maxilla and were followed for a minimum of 10 years from initial implant placement were included in this evaluation. Forty-four patients were identified: 40 with bilateral tilted implants and 4 with one tilted and one axial posterior implant. Eight patients received one-piece fixed porcelain-to-gold screw-retained restorations, and thirty-six patients received a fully implant-supported patient-removable Marius Bridge. Seventy-nine out of 84 originally loaded posterior tilted implants survived a minimum of 10 years loading; one tilted implant was lost at 10 years. Eight additional posterior implants were placed for either these lost tilted posterior implants or as proactive supplemental support; one of these replacement tilted implants survived for at least 10 years and is included in the data. All patients have maintained continuous fixed function throughout the follow-up period. Forty-one out of 44 patients continue with the original restoration, 33 without modification or removal of the fixed restoration or implant-connecting bar. One porcelain-to-gold and seven Marius Bridges had framework modifications to accommodate additional implants; 3 Marius Bridge restorations were replaced with a newer generation. Within the limits of this retrospective study, the results show that continuous fixed function of fully implant-supported maxillary restorations using posterior tilted implants in terminal positions of support as a sinus graft alternative combined with axial anterior implants is possible over a prolonged period. Loss of a posterior

  15. In vitro investigation of marginal accuracy of implant-supported screw-retained partial dentures.

    Science.gov (United States)

    Koke, U; Wolf, A; Lenz, P; Gilde, H

    2004-05-01

    Mismatch occurring during the fabrication of implant-supported dentures may induce stress to the peri-implant bone. The purpose of this study was to investigate the influence of two different alloys and the fabrication method on the marginal accuracy of cast partial dentures. Two laboratory implants were bonded into an aluminium block so that the distance between their longitudinal axes was 21 mm. Frameworks designed for screw-retained partial dentures were cast either with pure titanium (rematitan) or with a CoCr-alloy (remanium CD). Two groups of 10 frameworks were cast in a single piece. The first group was made of pure titanium, and the second group of a CoCr-alloy (remanium CD). A third group of 10 was cast in two pieces and then laser-welded onto a soldering model. This latter group was also made of the CoCr-alloy. All the frameworks were screwed to the original model with defined torque. Using light microscopy, marginal accuracy was determined by measuring vertical gaps at eight defined points around each implant. Titanium frameworks cast in a single piece demonstrated mean vertical gaps of 40 microm (s.d. = 11 microm) compared with 72 microm (s.d. = 40 microm) for CoCr-frameworks. These differences were not significant (U-test, P = 0.124) because of a considerable variation of the values for CoCr-frameworks (minimum: 8 microm and maximum: 216 microm). However, frameworks cast in two pieces and mated with a laser showed significantly better accuracy in comparison with the other experimental groups (mean: 17 microm +/- 6; P laser welding. Manufacturing the framework pieces separately and then welding them together provides the best marginal fit.

  16. Orbital Wall Reconstruction with Two-Piece Puzzle 3D Printed Implants: Technical Note

    Science.gov (United States)

    Mommaerts, Maurice Y.; Büttner, Michael; Vercruysse, Herman; Wauters, Lauri; Beerens, Maikel

    2015-01-01

    The purpose of this article is to describe a technique for secondary reconstruction of traumatic orbital wall defects using titanium implants that act as three-dimensional (3D) puzzle pieces. We present three cases of large defect reconstruction using implants produced by Xilloc Medical B.V. (Maastricht, the Netherlands) with a 3D printer manufactured by LayerWise (3D Systems; Heverlee, Belgium), and designed using the biomedical engineering software programs ProPlan and 3-Matic (Materialise, Heverlee, Belgium). The smaller size of the implants allowed sequential implantation for the reconstruction of extensive two-wall defects via a limited transconjunctival incision. The precise fit of the implants with regard to the surrounding ledges and each other was confirmed by intraoperative 3D imaging (Mobile C-arm Systems B.V. Pulsera, Philips Medical Systems, Eindhoven, the Netherlands). The patients showed near-complete restoration of orbital volume and ocular motility. However, challenges remain, including traumatic fat atrophy and fibrosis. PMID:26889349

  17. Patient’s satisfaction after 2-piece inflatable penile prosthesis implantation: An Italian multicentric study

    Directory of Open Access Journals (Sweden)

    Giorgio Gentile

    2016-03-01

    Full Text Available Introduction: Penile prosthesis implant represents a valuable solution for pts with severe erectile dysfunction (ED, non-responders to medical management. The aim of our study was to evaluate the satisfaction of patients (pts after 2-pieces inflatable penile prosthesis (IPP. Aim of the study: to evaluate safety, reliability and post-operative patient’s satisfaction after implantation of two-pieces IPP. Materials and Methods: This retrospective multicentric analysis concerns a group of 42 patients undergone 2-pieces IPP implantation from November 2005 to November 2013, in four Centers of proven experience. As a first step, a detailed review of all clinical reports was performed. Secondly, every patient was asked to fill the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS specifically modified, in order to assess their own satisfaction after surgery and, its impact on patient’s quality of sexual life. Results: 42 pts were evaluated (AMS-Ambicor: 28; Coloplast- Excell: 14; mean age, at time of operation: 60,7 years; mean follow up: 27,6 months; etiology of ED: vascular 23,8%, diabetes 19%, La Peyronie D. 7,1%, consequence of radical prostatectomy 31%, consequence of other pelvic surgery 11,9%, spinal trauma 7%. Mean operative time: 117 ± 58 min, mean postoperative hospital stay 3 ± 1,6 days. Post operative short-term complications: 4 pts (9,5%. Post operative long-term complications: 4 pts (9,5%. Long-term functional results (Questionnaire: 71% of pts (30 reported regular use of the prosthesis, at least 1 time/week, the satisfaction was good in 42% of pts (18, quite good in 33,3% (14, quite bad in 2,4% (1, very bad in 7,1% (3, 6 pts (14,4% didn’t answer. Conclusions: 2 pieces IPP appears to be associated with a low complication rate and good satisfaction of pts especially in the elderly. It also assures satisfactory rates of aesthetics and functional results.

  18. Learning and Memory Processes Following Cochlear Implantation: The Missing Piece of the Puzzle.

    Science.gov (United States)

    Pisoni, David B; Kronenberger, William G; Chandramouli, Suyog H; Conway, Christopher M

    2016-01-01

    At the present time, there is no question that cochlear implants (CIs) work and often work very well in quiet listening conditions for many profoundly deaf children and adults. The speech and language outcomes data published over the last two decades document quite extensively the clinically significant benefits of CIs. Although there now is a large body of evidence supporting the "efficacy" of CIs as a medical intervention for profound hearing loss in both children and adults, there still remain a number of challenging unresolved clinical and theoretical issues that deal with the "effectiveness" of CIs in individual patients that have not yet been successfully resolved. In this paper, we review recent findings on learning and memory, two central topics in the field of cognition that have been seriously neglected in research on CIs. Our research findings on sequence learning, memory and organization processes, and retrieval strategies used in verbal learning and memory of categorized word lists suggests that basic domain-general learning abilities may be the missing piece of the puzzle in terms of understanding the cognitive factors that underlie the enormous individual differences and variability routinely observed in speech and language outcomes following cochlear implantation.

  19. Implant supported overdentures--the Copenhagen experience

    DEFF Research Database (Denmark)

    Gotfredsen, K

    1997-01-01

    OBJECTIVES: To evaluate the functional and biological effect of implant-supported overdenture treatment in the lower jaw. METHODS AND MATERIALS: Thirty-two patients were consecutively treated with Astra Tech implants in the lower jaw for retaining overdentures. All implants had a diameter of 3.5 mm...... and all but two of the implants were longer than 10 mm. For the implant supported overdentures two methods of attachment were used, a bar or a ball. RESULTS: One of 69 fixtures was lost during the 4-5 year observation period. The mean bone loss for all fixtures was less than 0.2 mm per year. Complications...... quality and quantity is sufficient, two implants can support an overdenture in the lower jaw, providing prosthesis which functions well....

  20. The role of superstructure material on the stress distribution in mandibular full-arch implant-supported fixed dentures. A CT-based 3D-FEA.

    Science.gov (United States)

    Ferreira, Mayara Barbosa; Barão, Valentim Adelino; Faverani, Leonardo Perez; Hipólito, Ana Carolina; Assunção, Wirley Gonçalves

    2014-02-01

    This study evaluated the stress distribution in mandibular full-arch implant-supported fixed dentures with different veneering and metallic infrastructure materials, using three-dimensional finite element analysis. Ten models were obtained from an edentulous human mandible with a complete denture fixed by four implants. Acrylic resin (RES) and porcelain (POR) teeth were associated with infrastructures of titanium (Ti), gold (Au), silver-palladium (AgPd), chrome-cobalt (CoCr) and nickel-chrome (NiCr). A 100-N oblique was applied. The von Mises (σvM) and maximum (σmax) and minimum (σmin) principal stresses were obtained. The RES-AgPd group showed the lowest σvM values, while the RES-Ni-Cr group showed the highest. In the bone tissue, the RES-Au group was the only one that showed different σmax values with a 12% increase in comparison to the other groups which had similar stress values. In the implants, the groups with Ti, Au and AgPd infrastructures, either with porcelain or resin teeth, showed σvM values similar and lower in comparison to the groups with CoCr and NiCr infrastructures. The tooth veneering material influenced the stress values in metallic infrastructures, in which the acrylic resin had the highest values. The veneering and infrastructure materials have influence on stress values of implant-supported dentures, except for the peri-implant bone tissue. © 2013.

  1. Application of the 2-piece orthodontic C-implant for provisional restoration with laser welded customized coping: a case report.

    Science.gov (United States)

    Paek, Janghyun; Ahn, Hyo-Won; Jeong, Do-Min; Shim, Jeong-Seok; Kim, Seong-Hun; Chung, Kyu-Rhim

    2015-03-25

    This article presents the application of laser welding technique to fabricate an orthodontic mini-implant provisional restoration in missing area after limited orthodontic treatment. A 15-year-old boy case is presented. Two-piece orthodontic C-implant was placed after regaining space for missing right mandibular central incisor. Due to angular deviation of implant, customized abutment was required. Ready-made head part was milled and lingual part of customized abutment was made with non-precious metal. Two parts then were laser welded (Master 1000, Elettrolaser Italy, Verona, Italy) and indirect lab composite (3 M ESPE Sinfony, St. Paul, MN, USA) was built up. The patient had successful result, confirmed by clinical and radiographic examinations. Before the patient is ready to get a permanent restoration later on, this provisional restoration will be used. This case shows that a two-piece orthodontic C-implant system can be used to maintain small edentulous space after orthodontic treatment.

  2. Tunable superstructure fiber Bragg grating with chirp-distribution modulation based on the effect of external stress.

    Science.gov (United States)

    Huang, Yize; Li, Yi; Zhu, Huiqun; Tong, Guoxiang; Fang, Baoying; Li, Liu; Shen, Yujian; Zheng, Qiuxin; Liang, Qian; Yan, Meng; Wang, Feng; Qin, Yuan; Ding, Jie; Wang, Xiaohua

    2012-09-15

    We report an external stress modulation method for producing a superstructure fiber Bragg grating (FBG) with approximate cascaded resonant cavities composed of different index chirp distributions. The 15 mm uncoated apodized uniform-period FBG is pressed by the vertical stress from the upper 11 pieces of the pattern plate controlled by a piezoelectric ceramic actuator. The piece length is 1 mm, and the interval of the adjacent pieces is 0.4 mm. The reflectivity of the modulated FBG gradually shows six obvious multichannel 75%-85% reflection peaks with the increase of the vertical stress of each pattern-plate piece from 0 to 30 N. The channel spacing is steady at about 10 GHz for a C-band wavelength division multiplexing system.

  3. Learning and Memory Processes Following Cochlear Implantation: The Missing Piece of the Puzzle

    Science.gov (United States)

    Pisoni, David B.; Kronenberger, William G.; Chandramouli, Suyog H.; Conway, Christopher M.

    2016-01-01

    At the present time, there is no question that cochlear implants (CIs) work and often work very well in quiet listening conditions for many profoundly deaf children and adults. The speech and language outcomes data published over the last two decades document quite extensively the clinically significant benefits of CIs. Although there now is a large body of evidence supporting the “efficacy” of CIs as a medical intervention for profound hearing loss in both children and adults, there still remain a number of challenging unresolved clinical and theoretical issues that deal with the “effectiveness” of CIs in individual patients that have not yet been successfully resolved. In this paper, we review recent findings on learning and memory, two central topics in the field of cognition that have been seriously neglected in research on CIs. Our research findings on sequence learning, memory and organization processes, and retrieval strategies used in verbal learning and memory of categorized word lists suggests that basic domain-general learning abilities may be the missing piece of the puzzle in terms of understanding the cognitive factors that underlie the enormous individual differences and variability routinely observed in speech and language outcomes following cochlear implantation. PMID:27092098

  4. Biomechanical effects of two different collar implant structures on stress distribution under cantilever fixed partial dentures.

    Science.gov (United States)

    Merıç, Gökçe; Erkmen, Erkan; Kurt, Ahmet; Eser, Atilim; özden, Ahmet Utku

    2011-11-01

    The purpose of the study was to compare the effects of two distinct collar geometries of implants on stress distribution in the bone around the implants supporting cantilever fixed partial dentures (CFPDs) as well as in the implant-abutment complex and superstructures. The three-dimensional finite element method was selected to evaluate the stress distribution. CFPDs which was supported by microthread collar structured (MCS) and non-microthread collar structured (NMCS) implants was modeled; 300 N vertical, 150 N oblique and 60 N horizontal forces were applied to the models separately. The stress values in the bone, implant-abutment complex and superstructures were calculated. In the MCS model, higher stresses were located in the cortical bone and implant-abutment complex in the case of vertical load while decreased stresses in cortical bone and implant-abutment complex were noted within horizontal and oblique loading. In the case of vertical load, decreased stresses have been noted in cancellous bone and framework. Upon horizontal and oblique loading, a MCS model had higher stress in cancellous bone and framework than the NMCS model. Higher von Mises stresses have been noted in veneering material for NMCS models. It has been concluded that stress distribution in implant-supported CFPDs correlated with the macro design of the implant collar and the direction of applied force.

  5. Early Loading of Single-Piece Implant for Partially Edentulous Posterior Arch: A Prospective One-Year Case Report

    Directory of Open Access Journals (Sweden)

    Amol Beldar

    2013-01-01

    Full Text Available Implant therapy is now well established, and there is an increasing need for shorter rehabilitation time. Original prerequisites of osseointegration have been reassessed to satisfy continuously increasing patient's expectation of reduced treatment time, improved esthetics, and increased comfort. Shorter healing time may be appropriate in some circumstances, and examples of early loading have been reported in animal and human studies. However, to date there are insufficient data to determine a universally acceptable opinion on early loading of implants for single-tooth replacement. This case report involves early loading, combined with construction of a restoration, inserted directly after 6 weeks of implant surgery and followup of one year.

  6. In vitro synchrotron-based radiography of micro-gap formation at the implant–abutment interface of two-piece dental implants

    International Nuclear Information System (INIS)

    Rack, A.; Rack, T.; Stiller, M.; Riesemeier, H.; Zabler, S.; Nelson, K.

    2010-01-01

    Micro-radiography using hard X-ray synchrotron radiation is the first potential tool to allow an evaluation of the mechanical behavior of the dental implant–abutment complex during force application, thus enabling the enhancement of the design of dental implants which has been based on theoretical analysis to date. Micro-gap formation at the implant–abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites

  7. In vitro synchrotron-based radiography of micro-gap formation at the implant–abutment interface of two-piece dental implants

    Energy Technology Data Exchange (ETDEWEB)

    Rack, A., E-mail: arack@snafu.de [European Synchrotron Radiation Facility, Grenoble (France); Rack, T. [Charité, Department of Oral and Maxillofacial Surgery, Clinical Navigation and Robotics, Berlin (Germany); Stiller, M. [Charité, Department of Maxillofacial and Facial-Plastic Surgery, Division of Oral Medicine, Radiology and Surgery, Berlin (Germany); Riesemeier, H. [Bundesanstalt für Materialforschung und -prüfung, Division Structure Analysis, Polymer Analysis, Berlin (Germany); Zabler, S. [Technical University of Berlin, Institute for Materials Engineering (Germany); Nelson, K. [Charité, Department of Oral and Maxillofacial Surgery, Clinical Navigation and Robotics, Berlin (Germany)

    2010-03-01

    Micro-radiography using hard X-ray synchrotron radiation is the first potential tool to allow an evaluation of the mechanical behavior of the dental implant–abutment complex during force application, thus enabling the enhancement of the design of dental implants which has been based on theoretical analysis to date. Micro-gap formation at the implant–abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites.

  8. Visual function after implantation of single-piece toric hydrophilic acrylic intraocular lenses with hydrophobic surface six months after cataract surgery

    Directory of Open Access Journals (Sweden)

    Alja Črnej

    2012-06-01

    Conclusion: Patients with medium to high corneal astigmatism and implanted single-piece toric hydrophilic acrylic IOLs with hydrophobic surface have very good visual function six months postoperatively.

  9. Implants in free fibula flap supporting dental rehabilitation - Implant and peri-implant related outcomes of a randomized clinical trial.

    Science.gov (United States)

    Kumar, Vinay V; Ebenezer, Supriya; Kämmerer, Peer W; Jacob, P C; Kuriakose, Moni A; Hedne, Naveen; Wagner, Wilfried; Al-Nawas, Bilal

    2016-11-01

    The objective of this study was to assess the difference in success rates of implants when using two or four implant-supported-overdentures following segmental mandibular reconstruction with fibula free flap. This prospective, parallel designed, randomized clinical study was conducted with 1:1 ratio. At baseline, all participants already had segmental reconstruction of mandible with free fibula flap. The participants were randomized into two groups: Group-I received implant-supported-overdentures on two tissue-level implants and Group-II received implant-supported-overdentures on four tissue-level implants. Success rates of the implants were evaluated at 3 months, 6 months and 12 months following implant loading using marginal bone level changes as well as peri-implant indices (Buser et al., 1990). 52 patients were randomized into two treatment groups (26 each), out of which 18 patients (36 implants) of Group-I and 17 patients (68 implants) of Group-II were evaluated. One implant in Group-I was lost due to infective complications and one patient in the same group had superior barrel necrosis. There was a statistically significant increase at both time points (p = 0.03, p = 0.04 at 6 months, 12 months) in the amount of marginal bone loss in Group-I (0.4 mm, 0.5 mm at 6 months, 12 months) as compared to Group-II (0.1 mm, 0.2 mm at 6 months, 12 months). There were no clinically significant changes peri-implant parameters between both groups. Peri-implant soft tissue hyperplasia was seen in both groups, 32% of implants at 3-months, 26% at 6-months and 3% at 12-months follow-up. The results of this study show that patients with 2-implant-supported-overdentures had higher marginal bone loss as compared to patients with 4-implant-supported-overdentures. There were no clinically significant differences in peri-implant soft tissue factors in patients with 2- or 4-implant-supported-overdentures. Hyperplastic peri-implant tissues are common in the early implant

  10. Full Contoured Tooth-Implant Supported 3-Pointic All-Ceramic Denture During Occlusal Load Transfer in Lateral Region

    Directory of Open Access Journals (Sweden)

    Żmudzki J.

    2016-06-01

    Full Text Available Implant and a tooth supported dentures are avoided by dentists because of uneven distribution of occlusal loads between a stiffer implant and a more pliable tooth. The hypothesis was that a 3-point all-ceramic bridge supported on a natural second premolar tooth and a two-pieces typical implant bears safely mastication loads. The finite element analysis showed that the implant splinted by all-ceramic zirconium bridge with the second premolar was safe under lateral mastication load, but there was found an overload at wide zone of bone tissue around the implant under the load of 800 N. The patients can safely masticate, but comminution of hard food should be avoided and they should be instructed that after such an indiscretion they need to contact a dental professional, because, in spite of integrity of the prosthesis, the bone tissue around the implant may fail and there is a hazard of intrusion of the tooth.

  11. Settling of abutments into implants and changes in removal torque in five different implant-abutment connections. Part 1: Cyclic loading.

    Science.gov (United States)

    Kim, Ki-Seong; Han, Jung-Suk; Lim, Young-Jun

    2014-01-01

    The aim of this study was to evaluate and compare the settling of abutments into implants and the removal torque values (RTVs) before and after cyclic loading. Five different implant-abutment connections were tested: Ext = external butt joint + two-piece abutment; Int-H2 = internal hexagon + two-piece abutment; Int-H1 = internal hexagon + one-piece abutment; Int-O2 = internal octagon + two-piece abutment; and Int-O1 = internal octagon + one-piece abutment. Ten abutments from each group were secured to their corresponding implants (total n = 50). All samples were tested in a universal testing machine with a vertical load of 250 N for 100,000 cycles of 14 Hz. The amount of settling of the abutment into the implant was calculated from the change in the total length of the implant-abutment sample before and after loading, as measured with an electronic digital micrometer. The RTV after cyclic loading was compared to the initial RTV with a digital torque gauge. Statistical analysis was performed at a 5% significance level. A multiple-comparison test showed specific significant differences in settling values in each group after 250 N cyclic loading (Int-H1, Ext abutment type and related to the design characteristics of the implant-abutment connection.

  12. One Piece Orbitozygomatic Approach Based on the Sphenoid Ridge Keyhole

    DEFF Research Database (Denmark)

    Spiriev, Toma; Poulsgaard, Lars; Fugleholm, Kåre

    2016-01-01

    The one-piece orbitozygomatic (OZ) approach is traditionally based on the McCarty keyhole. Here, we present the use of the sphenoid ridge keyhole and its possible advantages as a keyhole for the one-piece OZ approach. Using transillumination technique the osteology of the sphenoid ridge...... was examined on 20 anatomical dry skull specimens. The results were applied to one-piece OZ approaches performed on freshly frozen cadaver heads. We defined the center of the sphenoid ridge keyhole as a superficial projection on the lateral skull surface of the most anterior and thickest part of the sphenoid...... ridge. It was located 22 mm (standard deviation [SD], 0.22 mm) from the superior temporal line; 10.7 mm (SD, 0.08 mm) posterior and 7.1 mm (SD, 0.22 mm) inferior to the frontozygomatic suture. The sphenoid ridge burr hole provides exposure of frontal, temporal dura as well as periorbita, which...

  13. A new system of implant abutment connection: how to improve a two piece implant system sealing.

    Science.gov (United States)

    Grecchi, F; DI Girolamo, M; Cura, F; Candotto, V; Carinci, F

    2017-01-01

    Implant dentistry has become one of the most successful dentistry techniques for replacing missing teeth. The success rate of implant dentistry is above 80%. However, peri-implantitis is a later complication of implant dentistry that if untreated, can lead to implant loss. One of the hypotized causes of peri-implantis is the bacterial leakage at the level of implant-abutment connection. Bacterial leakage is favored to the presence of a micro gap at the implant-abutment interface, allowing microorganisms to penetrate and colonize the inner part of the implant leading to biofilm accumulation and consequently to peri-implantitis development. To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Implants were immerged in a bacterial culture for twenty-four hours and then bacteria amount was measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 9%. The reported results are better to those of previous studies carried out on different implant systems. Until now, none implant-abutment system has been proven to seal the gap between implant and abutment.

  14. One piece reactor removal

    International Nuclear Information System (INIS)

    Chia, Wei-Min; Wang, Song-Feng

    1993-01-01

    The strategy of Taiwan Research Reactor Renewal plan is to remove the old reactor block with One Piece Reactor Removal (OPRR) method for installing a new research reactor in original building. In this paper, the engineering design of each transportation works including the work method, the major equipments, the design policy and design criteria is described and discussed. In addition, to ensure the reactor block is safety transported for storage and to guarantee the integrity of reactor base mat is maintained for new reactor, operation safety is drawn special attention, particularly under seismic condition, to warrant safe operation of OPRR. ALARA principle and Below Regulatory Concern (BRC) practice were also incorporated in the planning to minimize the collective dose and the total amount of radioactive wastes. All these activities are introduced in this paper. (J.P.N.)

  15. Study on superstructure in ion co-doped BiFeO3 by using transmission electron microscopy

    Science.gov (United States)

    Pu, Shi-Zhou; Guo, Chao; Li, Mei-Ya; Chen, Zhen-Lian; Zou, Hua-Min

    2015-04-01

    La3+ and V5+ co-doped BiFeO3 ceramics are synthesized by rapid liquid sintering technique. The modulated structure in Bi0.85La0.15Fe0.97V0.03O3 is investigated by using transmission electron microscopy (TEM). Two kinds of superstructures are observed in the samples. One is the component modulated superstructure and twin-domain, which is generated by La3+ ordered substitution for Bi3+ and frequently appears. The chemical composition of the superstructure is explored by x-ray energy dispersive spectroscopy (EDS). The model of the ordered structure is proposed. Simulation based on the model is conducted. The second is the fluorite-type δ-Bi2O3 related superstructure. The relation between the ferroelectric property and the microstructure of the sample is also discussed. Project supported by the National Natural Science Foundation of China (Grant Nos. 51372174, 11074193, and 51132001) and the Fundamental Research Funds for the Central Universities.

  16. Nanoparticle assemblies and superstructures

    National Research Council Canada - National Science Library

    Kotov, Nicholas A

    2006-01-01

    ... building blocks of larger and more complex systems. Therefore, the present challenge of nanoscale science is to shift from making certain building blocks to organizing them in one-, two-, and three-dimensional structures. Such assemblies and superstructures are the next logical step in the development of nanoscience and nanotechnology. In this re...

  17. Classification system on the selection of number of implants and superstructure design on the basis available vertical restorative space and interforaminal distance for implant supported mandibular overdenture

    Directory of Open Access Journals (Sweden)

    Akshay Bhargava

    2016-01-01

    Full Text Available Purpose: The rehabilitation of the edentulous mandible is a challenge due to various limiting factors, of which the available vertical restorative space (AVRS has been well understood in the literature. However, other anatomic variations such as arch form, arch size, and also the interforaminal distance (IFD (due to the presence of mandibular nerve are influential in the selection of size and position of implants, and thereby the prosthetic design. Materials and Method: In the present study, 30 edentulous patients from a group of 300 edentulous patients, representing all the three jaw relations (Class I, II, and III were evaluated for designing a classification that could help in a comprehensive treatment plan for the edentulous mandible. Dental panoramic radiographs of each individual with a trial or final prosthesis were made. The horizontal IFD and AVRS values were calculated. Results: One-way analysis of variance followed by post-hoc test (multiple comparison and Bonferroni method having P < 0.05 as significant value showed an overall mean of 38.9 mm for horizontal distance and 13.69 mm for the AVRS in 30 edentulous patients. Conclusion: The results showed that in the majority of cases (90% there is insufficient space to place a bar attachment supported by five implants for mandibular overdentures. This suggests that a universal treatment plan cannot be followed due to varying anatomic factors. Hence, it becomes imperative to have a set of clinical guidelines based on the AVRS and IFD, for the selection of implant number and type of attachment. The article proposes a simple classification system based on the AVRS and IFD for establishing guidelines in the treatment planning of the edentulous mandible, to aid in selection of implant size, number, and position along with the associated prosthetic design.

  18. Electrochemical Behaviour and Galvanic Effects of Titanium Implants Coupled to Metallic Suprastructures in Artificial Saliva

    Science.gov (United States)

    Mellado-Valero, Ana; Igual Muñoz, Anna; Guiñón Pina, Virginia

    2018-01-01

    The aim of the present study is to analyze the electrochemical behavior of five different dental alloys: two cobalt-chromium alloys (CoCr and CoCr-c), one nickel-chromium-titanium alloy (NiCrTi), one gold-palladium alloy (Au), and one titanium alloy (Ti6Al4V), and the galvanic effect when they are coupled to titanium implants (TiG2). It was carried out by electrochemical techniques (open circuit measurements, potentiodynamic curves and Zero-Resistance Ammetry) in artificial saliva (AS), with and without fluorides in different acidic conditions. The studied alloys are spontaneously passivated, but NiCrTi alloy has a very narrow passive domain and losses its passivity in presence of fluorides, so is not considered as a good option for implant superstructures. Variations of pH from 6.5 to 3 in artificial saliva do not change the electrochemical behavior of Ti, Ti6Al4V, and CoCr alloys, and couples, but when the pH of the artificial saliva is below 3.5 and the fluoride content is 1000 ppm Ti and Ti6Al4V starts actively dissolving, and CoCr-c superstructures coupled to Ti show acceleration of corrosion due to galvanic effects. Thus, NiCrTi is not recommended for implant superstructures because of risk of Ni ion release to the body, and fluorides should be avoided in acidic media because Ti, Ti6Al4V, and CoCr-c superstructures show galvanic corrosion. The best combinations are Ti/Ti6Al4V and Ti/CoCr as alternative of noble gold alloys. PMID:29361767

  19. Solving intraocular lens-related pigment dispersion syndrome with repositioning of primary sulcus implanted single-piece IOL in the capsular bag.

    Science.gov (United States)

    Kohnen, Thomas; Kook, Daniel

    2009-08-01

    We describe 2 cases of pigment dispersion syndrome (PDS) after uneventful phacoemulsification and implantation of a posterior chamber single-piece intraocular lens (IOL) with a sharp-edge design. In both cases, several days after IOL implantation, marked pigment dispersion was seen on the iris and in the trabecular meshwork, associated with an elevation in intraocular pressure (IOP). Thorough examination showed that the implanted IOL was in the ciliary sulcus. After surgical repositioning of both IOLs in the capsular bag, the pigment dispersion regressed and the IOP returned to normal limits. The 2 cases suggest that particularly in PDS patients, an IOL with an anterior sharp-edge design should be implanted in the capsular bag. Implantation in the ciliary sulcus should be avoided.

  20. Macro design effects on stress distribution around implants: a photoelastic stress analysis.

    Science.gov (United States)

    Ozkir, Serhat Emre; Terzioglu, Hakan

    2012-01-01

    Biomechanics is one of the main factors for achieving long-term success of implant supported prostheses. Long-term failures mostly depend on biomechanical complications. It is important to distinguish the effects of macro design of the implants. In this study, the photoelastic response of four different types of implants that were inserted with different angulations were comparatively analyzed. The implant types investigated were screw cylinder (ITI, Straumann AG, Basel, Switzerland), stepped cylinder (Frialit2, Friadent GmbH, Manheim, Germany), root form (Camlog Rootline, Alatatec, Wilshelm, Germany), and cylindrical implant, with micro-threads on the implant neck (Astra, AstraTech, Mölndal, Sweden). In the test models, one of the implants was inserted straight, while the other one was aligned mesially with 15° angles. The superstructures were prepared as single crowns. A 150N loading was applied to the restorations throughout the test. A comparison of the implant designs showed that there were no significant differences between the straight implants; however, between the inclined implants, the most favorable stress distribution was seen with the stepped cylinder implants. The least favorable stress concentration was observed around the root formed implants. Microthreads around the implant neck appeared to be effective in a homogenous stress distribution. Observations showed that misaligned implants caused less stress than straight implants, but the stress concentrations were not homogenous. As there were observable differences between the implant types, straight placed cylindrical implants showed better stress distribution characteristics, while inclined tapering implants had better stress distribution characteristics.

  1. One-Piece Faraday Generator: A Paradoxical Experiment from 1851

    Science.gov (United States)

    Crooks, M. J.; And Others

    1978-01-01

    Describes an experiment based on Faraday's one-piece generator, where the rotating disk is replaced by a cylindrical permanent magnet. Explains the apparent paradox that an observer in an inertial frame could measure his absolute velocity. (GA)

  2. Superstructure of stapes

    International Nuclear Information System (INIS)

    Horiuchi, Yasuharu; Hunai, Hiroaki; Ichimura; Keiiti; Iinuma, Toshitaka; Oyama, Kazuyuki

    1989-01-01

    High-resolution Computed Tomography (HRCT) of the temporal bone has now become a routine test for the diagnosis of various temporal bone lesions. Correct assessment of such minute structures as ossicles, especially stapes, is important in the pre-operative HRCT evaluation. On the other hand, analysis for the reliability of HRCT findings has not been done, including the superstructure of the stapes. A retrospectively study was done in order to assess the availability of HRCT findings in axial overlapping scans in 226 ears, with respect to the superstructures of stapes. The study was concerned with the analysis of HRCTs of 148 normal ears, 71 ears of chronic otitis media and 7 ears of ossicular abnormalities. HRCT findings were compared to those of surgeries in pathological cases. The present study revealed that the superstructures of stapes are noted in 70% when the stapes is surrounded by air. The major limitations in the proper analysis of stapes by HRCT are partial volume averaging and effects of soft tissue silhouetting, this is especially so when the stapes is surrounded by soft tissue density. (author)

  3. Standard plans for timber bridge superstructures

    Science.gov (United States)

    James P. Wacker; Matthew S. Smith

    2001-01-01

    These standardized bridge plans are for superstructures consisting of treated timber. Seven superstructure types are includes: five longitudinal and two transverse deck systems. Both HS520 and HS25 loadings are included, along with L/360 and L/500 deflection criteria.

  4. Fracture analysis of randomized implant-supported fixed dental prostheses

    Science.gov (United States)

    Esquivel-Upshaw, Josephine F.; Mehler, Alex; Clark, Arthur E.; Neal, Dan; Anusavice, Kenneth J.

    2014-01-01

    Objective Fractures of posterior fixed dental all-ceramic prostheses can be caused by one or more factors including prosthesis design, flaw distribution, direction and magnitude of occlusal loading, and nature of supporting infrastructure (tooth root/implant), and presence of adjacent teeth. This clinical study of implant-supported, all-ceramic fixed dental prostheses, determined the effects of (1) presence of a tooth distal to the most distal retainer; (2) prosthesis loading either along the non-load bearing or load bearing areas; (3) presence of excursive contacts or maximum intercuspation contacts in the prosthesis; and (4) magnitude of bite force on the occurrence of veneer ceramic fracture. Methods 89 implant-supported FDPs were randomized as either a three-unit posterior metal-ceramic (Au-Pd-Ag alloy and InLine POM, Ivoclar, Vivadent) FDP or a ceramic-ceramic (ZirCAD and ZirPress, Ivoclar, Vivadent) FDP. Two implants (Osseospeed, Dentsply) and custom abutments (Atlantis, Dentsply) supported these FDPs, which were cemented with resin cement (RelyX Universal Cement). Baseline photographs were made with markings of teeth from maximum intercuspation (MI) and excursive function. Patients were recalled at 6 months and 1 to 3 years. Fractures were observed, their locations recorded, and images compared with baseline photographs of occlusal contacts. Conclusion No significant relationship exists between the occurrence of fracture and: (1) the magnitude of bite force; (2) a tooth distal to the most distal retainer; and (3) contacts in load-bearing or non-load-bearing areas. However, there was a significantly higher likelihood of fracture in areas with MI contacts only. Clinical Significance This clinical study demonstrates that there is a need to evaluate occlusion differently with implant-supported prostheses than with natural tooth supported prostheses because of the absence of a periodontal ligament. Implant supported prostheses should have minimal occlusion and

  5. Superstructures: First Cold Test and Future Applications

    International Nuclear Information System (INIS)

    J. Sekutowicz; C Albrecht; V Ayvazyan; R Bandelmann; T Buttner; P Castro; S Choroba; J Eschke; B Faatz; A Gossel; K Honkavaara; B Horst; J Iverson; K Jensch; H Kaiser; R Kammering; G Kreps; D Kostin; J Lorkiewicz; R Lange; A Matheisen; W -D Moller; H -B Peters; D Proch; K Rehlich; H Schlarb; S Schrieber; D Reschke; S Simrock; W Singer; X Singer; K Twarowski; T Weichert; M Wojtkiewicz; G Wendt; K Zapfe; M Liepe; M Huening; M Ferrario; E Plawski; C Pagani; P Kneisel; G Wu; N Baboi; C Thomas; H Chen; W Huang; C Tang; S Zheng

    2003-01-01

    Superstructures, chains of superconducting multi-cell cavities (subunits) connected by e/2 long tube(s) have been proposed as an alternative layout for the TESLA main accelerator [1]. After three years of preparation, two superstructures, each made of two weakly coupled superconducting 7-cell subunits driven by a single Fundamental Power Coupler (FPC), have been installed in the Tesla Test Facility linac for beam tests. Energy stability, HOM damping, frequency and field adjustment methods were tested. The measured results confirme Superstructures, chains of superconducting multi-cell cavities (subunits) connected by e/2 long tube(s) have been proposed as an alternative layout for the TESLA main accelerator [1]. After three years of preparation, two superstructures, each made of two weakly coupled superconducting 7-cell subunits driven by a single Fundamental Power Coupler (FPC), have been installed in the Tesla Test Facility linac for beam tests. Energy stability, HOM damping, frequency and field adjustment methods were tested. The measured results confirmed expectation on the superstructure performance and proved that an alternative layout for the 800 GeV upgrade of the TESLA collider is feasible. We report on the test and give here an overview of its results. The tests confirmed very good damping of HOMs in superstructures and thus has opened a possible new application of this concept to high current energy recovery machines. We have built two 1.5 GHz copper models of two superstructures: 2x5-cells and 2x2-cells to prove further improvement of HOM damping. This contribution presents also measured results on these models. d expectations on the superstructure performance and proved that an alternative layout for the 800 GeV upgrade of the TESLA collider is feasible. We report on the test and give here an overview of its results

  6. Evaluation of anterior segment changes using ultrasound biomicroscopy following phacoemulsification and implantation of one-piece and three-piece intraocular lenses in high myopia

    Directory of Open Access Journals (Sweden)

    Reham Mohamed Samy

    2017-01-01

    The study of this correlation is to help in answering an important question − that is, does one diameter IOL fit all capsular bags? The statistical analyses in both groups point to a statistically significant correlation between the diameters of the capsular bags and the diameters of the implanted IOLs in both groups A and B, which demonstrates the absence of fitting of both sorts of IOLs in relation to the enlarged capsular bags of the highly myopic eyes − i.e. it focuses on the divergence between the size of the IOLs and that of the capsular bag.

  7. Do Puzzle Pieces and Autism Puzzle Piece Logos Evoke Negative Associations?

    Science.gov (United States)

    Gernsbacher, Morton Ann; Raimond, Adam R.; Stevenson, Jennifer L.; Boston, Jilana S.; Harp, Bev

    2018-01-01

    Puzzle pieces have become ubiquitous symbols for autism. However, puzzle-piece imagery stirs debate between those who support and those who object to its use because they believe puzzle-piece imagery evokes negative associations. Our study empirically investigated whether puzzle pieces evoke negative associations in the general public.…

  8. Fracture strength of zirconia implant abutments on narrow diameter implants with internal and external implant abutment connections: A study on the titanium resin base concept.

    Science.gov (United States)

    Sailer, Irena; Asgeirsson, Asgeir G; Thoma, Daniel S; Fehmer, Vincent; Aspelund, Thor; Özcan, Mutlu; Pjetursson, Bjarni E

    2018-04-01

    There is limited knowledge regarding the strength of zirconia abutments with internal and external implant abutment connections and zirconia abutments supported by a titanium resin base (Variobase, Straumann) for narrow diameter implants. To compare the fracture strength of narrow diameter abutments with different types of implant abutment connections after chewing simulation. Hundred and twenty identical customized abutments with different materials and implant abutment connections were fabricated for five groups: 1-piece zirconia abutment with internal connection (T1, Cares-abutment-Straumann BL-NC implant, Straumann Switzerland), 1-piece zirconia abutment with external hex connection (T2, Procera abutment-Branemark NP implant, Nobel Biocare, Sweden), 2-piece zirconia abutments with metallic insert for internal connection (T3, Procera abutment-Replace NP implant, Nobel Biocare), 2-piece zirconia abutment on titanium resin base (T4, LavaPlus abutment-VarioBase-Straumann BL-NC implant, 3M ESPE, Germany) and 1-piece titanium abutment with internal connection (C, Cares-abutment-Straumann BL-NC implant, Straumann, Switzerland). All implants had a narrow diameter ranging from 3.3 to 3.5 mm. Sixty un-restored abutments and 60 abutments restored with glass-ceramic crowns were tested. Mean bending moments were compared using ANOVA with p-values adjusted for multiple comparisons using Tukey's procedure. The mean bending moments were 521 ± 33 Ncm (T4), 404 ± 36 Ncm (C), 311 ± 106 Ncm (T1) 265 ± 22 Ncm (T3) and 225 ± 29 (T2) for un-restored abutments and 278 ± 84 Ncm (T4), 302 ± 170 Ncm (C), 190 ± 55 Ncm (T1) 80 ± 102 Ncm (T3) and 125 ± 57 (T2) for restored abutments. For un-restored abutments, C and T4 had similar mean bending moments, significantly higher than those of the three other groups (p internal connection had higher bending moments than zirconia abutments with external connection (T2) (p internal connected zirconia

  9. A comparison of the accuracy of polyether, polyvinyl siloxane, and plaster impressions for long-span implant-supported prostheses.

    Science.gov (United States)

    Hoods-Moonsammy, Vyonne J; Owen, Peter; Howes, Dale G

    2014-01-01

    The purpose of this study was to compare the capacity of different impression materials to accurately reproduce the positions of five implant analogs on a master model by comparing the resulting cast with the stainless steel master model. The study was motivated by the knowledge that distortions can occur during impression making and the pouring of casts and that this distortion may produce inaccuracies of subsequent restorations, especially long-span castings for implant superstructures. The master model was a stainless steel model with five implant analogs. The impression materials used were impression plaster (Plastogum, Harry J Bosworth), a polyether (Impregum Penta, 3M ESPE), and two polyvinyl siloxane (PVS) materials (Aquasil Monophase and Aquasil putty with light-body wash, Dentsply). Five impressions were made with each impression material and cast in die stone under strictly controlled laboratory conditions. The positions of the implants on the master model, the impression copings, and the implant analogs in the subsequent casts were measured using a coordinate measuring machine that measures within 4 μm of accuracy. Statistical analyses indicated that distortion occurred in all of the impression materials, but inconsistently. The PVS monophase material reproduced the master model most accurately. Although there was no significant distortion between the impressions and the master model or between the impressions and their casts, there were distortions between the master model and the master casts, which highlighted the cumulative effects of the distortions. The polyether material proved to be the most reliable in terms of predictability. The impression plaster displayed cumulative distortion, and the PVS putty with light body showed the least reliability. Some of the distortions observed are of clinical significance and likely to contribute to a lack of passive fit of any superstructure. The inaccuracy of these analog materials and procedures suggested

  10. Control superstructure of rigid polyelectrolytes in oppositely charged hydrogels via programmed internal stress

    Science.gov (United States)

    Takahashi, Riku; Wu, Zi Liang; Arifuzzaman, Md; Nonoyama, Takayuki; Nakajima, Tasuku; Kurokawa, Takayuki; Gong, Jian Ping

    2014-08-01

    Biomacromolecules usually form complex superstructures in natural biotissues, such as different alignments of collagen fibres in articular cartilages, for multifunctionalities. Inspired by nature, there are efforts towards developing multiscale ordered structures in hydrogels (recognized as one of the best candidates of soft biotissues). However, creating complex superstructures in gels are hardly realized because of the absence of effective approaches to control the localized molecular orientation. Here we introduce a method to create various superstructures of rigid polyanions in polycationic hydrogels. The control of localized orientation of rigid molecules, which are sensitive to the internal stress field of the gel, is achieved by tuning the swelling mismatch between masked and unmasked regions of the photolithographic patterned gel. Furthermore, we develop a double network structure to toughen the hydrogels with programmed superstructures, which deform reversibly under large strain. This work presents a promising pathway to develop superstructures in hydrogels and should shed light on designing biomimetic materials with intricate molecular alignments.

  11. Evaluation of Satisfaction Level in Patients With Mandibular Implant Supported Overdentures

    Directory of Open Access Journals (Sweden)

    Masoumeh khoshhal

    2016-01-01

    Full Text Available Background Implant-supported overdentures could have many benefits for patients, especially in the lower jaws. As a matter of fact, the most common reason for prescribing mandibular overdenture is dissatisfaction of patients with mandibular dentures usually because of a lack of retention, stability and function and speech difficulties. On the other hand, patients' expectations of overdenture treatments are their main disadvantage. Objectives The aim of this study was to evaluate the satisfaction of patients who had received mandibular implant supported overdenture treatment with different number of implants. Patients and Methods This study was a descriptive cross-sectional study. Twenty-five patients with a mean age of 62.7 years who had received mandibular implant supported overdenture treatment at the dental school of Hamadan University of Medical Sciences were enrolled. Among these patients, six had overdentures supported by one implant, nine had overdentures supported by two implants, two had overdentures supported by three implants, five had overdentures supported by four implants and three had overdentures supported by five implants. The visual analogue scale (VAS questionnaire was used to evaluate the general satisfaction, comfort, esthetic, fitness, satisfaction of chewing and social communication, and the data was analyzed by the analysis of variance (ANOVA test. Results All patients in all five groups were satisfied with their overdentures; however there was no significant relationship between the number of implants and fitness (P = 0.446, esthetic (P = 0.843, comfort (P = 0.805, satisfaction of chewing (P = 0.133, social communication (P = 0.322 and general satisfaction (P = 0.493. Conclusions There was no difference in satisfaction level of patients who had received mandibular overdentures with different number of implants.

  12. Turbulent Superstructures in Rayleigh-Bénard convection at different Prandtl number

    Science.gov (United States)

    Schumacher, Jörg; Pandey, Ambrish; Ender, Martin; Westermann, Rüdiger; Scheel, Janet D.

    2017-11-01

    Large-scale patterns of the temperature and velocity field in horizontally extended cells can be considered as turbulent superstructures in Rayleigh-Bénard convection (RBC). These structures are obtained once the turbulent fluctuations are removed by a finite-time average. Their existence has been reported for example in Bailon-Cuba et al.. This large-scale order obeys a strong similarity with the well-studied patterns from the weakly nonlinear regime at lower Rayleigh number in RBC. In the present work we analyze the superstructures of RBC at different Prandtl number for Prandtl values between Pr = 0.005 for liquid sodium and 7 for water. The characteristic evolution time scales, the typical spatial extension of the rolls and the properties of the defects of the resulting superstructure patterns are analyzed. Data are obtained from well-resolved spectral element direct numerical simulations. The work is supported by the Priority Programme SPP 1881 of the Deutsche Forschungsgemeinschaft.

  13. Erection of the Rokko island bridge superstructure. Rokko island kyojobu koji no seko

    Energy Technology Data Exchange (ETDEWEB)

    Tanino, A; Sakai, Y; Morikawa, Y; Sakoda, H; Egami, T; Maeda, Y; Shikata, H; Miyazaki, K [Kawasaki Heavy Industries, Ltd., Tokyo (Japan)

    1993-10-20

    Erection of the superstructure of the Rokko Island Bridge (220 m long) was outlined which connects Rokko Island with Kobe City. The weight of the superstructure was nearly 7,300 tons, the highest single weight of any unit bridge structures ever installed in Japan. Because various ships cruised at the erection site every day, the superstructure was assembled and painted in a factory, and after shipped to its destination on a large barge, it was hoisted onto the previously constructed piers by three giant floating cranes (FC). Since it was most essential to match hook loads among the FCs, the hook load control system was developed in which hook load data of each FC were sent to a control center every 4-5 seconds by wireless transmission, and the data as well as their required control limits were graphically displayed to support a situation recognition, resulting in rapid and safe erection. The erection work started from that of piers in Aug. 1992, and that of the superstructure started in Nov. 1992 and ended in Feb. 1993. 13 figs., 4 tabs.

  14. A three-dimensional finite element study on the stress distribution pattern of two prosthetic abutments for external hexagon implants.

    Science.gov (United States)

    Moreira, Wagner; Hermann, Caio; Pereira, Jucélio Tomás; Balbinoti, Jean Anacleto; Tiossi, Rodrigo

    2013-10-01

    The purpose of this study was to evaluate the mechanical behavior of two different straight prosthetic abutments (one- and two-piece) for external hex butt-joint connection implants using three-dimensional finite element analysis (3D-FEA). Two 3D-FEA models were designed, one for the two-piece prosthetic abutment (2 mm in height, two-piece mini-conical abutment, Neodent) and another one for the one-piece abutment (2 mm in height, Slim Fit one-piece mini-conical abutment, Neodent), with their corresponding screws and implants (Titamax Ti, 3.75 diameter by 13 mm in length, Neodent). The model simulated the single restoration of a lower premolar using data from a computerized tomography of a mandible. The preload (20 N) after torque application for installation of the abutment and an occlusal loading were simulated. The occlusal load was simulated using average physiological bite force and direction (114.6 N in the axial direction, 17.1 N in the lingual direction and 23.4 N toward the mesial at an angle of 75° to the occlusal plan). The regions with the highest von Mises stress results were at the bottom of the initial two threads of both prosthetic abutments that were tested. The one-piece prosthetic abutment presented a more homogeneous behavior of stress distribution when compared with the two-piece abutment. Under the simulated chewing loads, the von Mises stresses for both tested prosthetic-abutments were within the tensile strength values of the materials analyzed which thus supports the clinical use of both prosthetic abutments.

  15. Implementing Composite Superstructures in Large Passenger Ships

    DEFF Research Database (Denmark)

    Karatzas, Vasileios; Berggreen, Christian; Jensen, Jørgen Juncher

    2015-01-01

    This study focuses on the structural response of the part of the superstructure of a RoPax ferry that has been redesigned using composite materials. The composite superstructure is presented and subsequently compared to the existing steel design considering different loading conditions by the use...

  16. Mandibular implant-supported overdentures: Prosthetic overview

    Directory of Open Access Journals (Sweden)

    Fahad A Al-Harbi

    2018-01-01

    Full Text Available Implant-supported overdentures are becoming the treatment of choice for the completely edentulous mandible. They significantly improve the quality of life in edentulous patients. For this review article, the literature was searched to identify pertinent studies. No meta-analysis was conducted because of high heterogeneity within the literature. Accordingly, in this review article, the author provides an update on implant-supported mandible overdentures with regard to the number of implants, type of loading, stress–strain distribution, mode of implant-to-denture attachment, occlusal considerations and complications.

  17. Implant-supported mandibular removable partial dentures; patient-based outcome measures in relation to implant position.

    Science.gov (United States)

    Jensen, Charlotte; Raghoebar, Gerry M; Kerdijk, Wouter; Meijer, Henny J A; Cune, Marco S

    2016-12-01

    To assess the benefits of implant support to Removable Partial Dentures (RPD) in patients with a bilateral free-ending situation in the mandible and to determine the most favorable implant position: the premolar (PM) or the molar (M) region. Thirty subjects with a bilateral unbounded posterior saddle received 2 PM and 2M implants. A new RPD was placed. Implant support was provided 3 months later. Two PM implants supported the RPD. After 3 months the 2M implants were used or vice versa. Outcome measures included oral health related quality of life (OHIP-NL49), general health status (SF-36), contentment assessed on a Visual Analogue Scale (VAS) and the number of hours that the RPD was worn. Data were collected prior to treatment, 3 months after having functioned with a new RPD and after 3 and 6 months with implant support. Finally, patients expressed their preferred implant position. The general health status (SF-36) was not influenced. OHIP-NL49 values and mean wearing-time were statistical significantly more favorable for ISRPD's, regardless of the implant position. Per day, the ISRPD's were worn 2-3h more than the unsupported new RPD. Patients' expectations were met as the VAS-scores of anticipated and realized contentment did not reach a statistical significant level (p>0.05). VAS scores for ISRPD's with M implant support were higher than for PM implant support. Finally, 56.7% of subjects preferred the M implant support, 13.3% expressed no preference and 30% opted for PM implant support. Mandibular implant support favorably influences oral health related patient-based outcome measures in patients with a bilateral free-ending situation. The majority of patients prefer the implant support to be in the molar region. Patients with a bilateral free-ending situation in the mandible opposed by a maxillary denture benefit from implant support to their mandibular removable partial denture. Most patients prefer this support to be in the molar region. Copyright © 2016

  18. The Efficacy of Supportive Peri-Implant Therapies in Preventing Peri-Implantitis and Implant Loss: a Systematic Review of the Literature

    Directory of Open Access Journals (Sweden)

    Ausra Ramanauskaite

    2016-09-01

    Full Text Available Objectives: To study the efficacy of supportive peri-implant therapies in preventing clinical and radiological signs of peri-implantitis and implant loss. Material and Methods: Longitudinal human studies, published between January 1, 2006, and February 1, 2016, were included based on an electronic search using MEDLINE and EMBASE databases and complemented by a manual search. Articles were included only if 1 they comprised a group of patients involved in/adhering to regular supportive peri-implant therapies (SPTs and a control group without such therapies or with poor adherence to them, 2 the protocol of the SPTs was clearly described and 3 the outcome was indicated by means of clinical/radiological changes or implant loss. Results: After initially identifying a total of 710 titles and abstracts, 12 full text articles were selected for eligibility assessment. Seven studies, three prospective and four retrospective, fulfilled the inclusion criteria for this review. The frequency of recall visits varied between the studies from a minimum of one visit every three months to an individually tailored regimen. In all the studies a lack of SPTs or poor adherence to them resulted in significantly higher frequencies of sites with mucosal bleeding, deepened peri-implant pockets or alveolar bone loss. In line with the above, a lack of/poor adherence to SPTs was associated with higher implant loss. Conclusions: To prevent peri-implantitis, an individually tailored supportive programme based on patient motivation and re-instruction in oral hygiene measures combined with professional implant cleaning seem to be crucial.

  19. Marginal bone-level alterations of loaded zirconia and titanium dental implants: an experimental study in the dog mandible.

    Science.gov (United States)

    Thoma, Daniel S; Benic, Goran I; Muñoz, Fernando; Kohal, Ralf; Sanz Martin, Ignacio; Cantalapiedra, Antonio G; Hämmerle, Christoph H F; Jung, Ronald E

    2016-04-01

    The aim was to test whether or not the marginal bone-level alterations of loaded zirconia implants are similar to the bone-level alterations of a grade 4 titanium one-piece dental implant. In six dogs, all premolars and the first molars were extracted in the mandible. Four months later, three zirconia implants (BPI, VC, ZD) and a control titanium one-piece (STM) implant were randomly placed in each hemimandible and left for transmucosal healing (baseline). Six months later, CAD/CAM crowns were cemented. Sacrifice was scheduled at 6-month postloading. Digital X-rays were taken at implant placement, crowns insertion, and sacrifice. Marginal bone-level alterations were calculated, and intra- and intergroup comparisons performed adjusted by confounding factors. Implants were successfully placed. Until crown insertion, two implants were fractured (one VC, one ZD). At sacrifice, 5 more implants were (partly) fractured (one BPI, four ZD), and one lost osseointegration (VC). No decementation of crowns occurred. All implant systems demonstrated a statistically significant (except VC) loss of marginal bone between baseline and crown insertion ranging from 0.29 mm (VC; P = 0.116) to 0.80 mm (ZD; P = 0.013). The estimated marginal bone loss between baseline and 6 months of loading ranged between 0.19 mm (BPI) and 1.11 mm (VC), being statistically significant for STM and VC only (P implants and control implants (STM vs. BPI P = 0.007; vs. VC P = 0.001; vs. ZD P = 0.011). Zirconia implants were more prone to fracture prior to and after loading with implant-supported crowns compared to titanium implants. Individual differences and variability in the extent of the bone-level changes during the 12-month study period were found between the different implant types and materials. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Pseudo-capsule “coffin effect”: How to prevent penile retraction after implant of three-piece inflatable prosthesis

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    Enrico Caraceni

    2014-06-01

    Full Text Available Objective: Following three-component implantation of a penile prosthesis, some patients are dissatisfied with their penile length. This may be due to the procedure by itself or pre-existing risk factors or psychological reasons. We supposed that formation of a restricted pseudo-capsule due to a late prosthesis activation can inhibit later system expansion. We aimed to identify the presence or absence of penile retraction after implant and to prevent it by immediate prosthesis activation after implantation. Material and methods. Forty-six patients operated with three-piece inflatable penile prosthesis (AMS 700 CX o LGX were enrolled. In 27 patients prosthesis was first activated four weeks after surgery (NEA group and in 19 patients prosthesis was activated immediately after surgery (DEA group. Length and girth of the penis was evaluated before (in DEA group and after the surgical procedure. Results. The average post implant dorsal length of the erect penis in group NEA was found 3.28 cm shorter than in group with early activation (DEA. In DEA group there was no lenght difference between pre-operative stretching (14.57 cm and post operative erection (14.98 cm. When early activation was not performed, the clinical result was a smaller penis in erect phase. Conclusion. Reduced lenght of the penis after implantation can be caused by the presence of a pseudo-capsule that limits the elongation of the prosthesis and of the penis (“coffin effect”. Timing of first activation seems to be the key in order to prevent the risk of penile retraction after implantation. Early activation is identified as the best measure to maintain the length of the pre implant erect penis after the prosthetic hydraulic implant.

  1. Voids and superstructures: correlations and induced large-scale velocity flows

    Science.gov (United States)

    Lares, Marcelo; Luparello, Heliana E.; Maldonado, Victoria; Ruiz, Andrés N.; Paz, Dante J.; Ceccarelli, Laura; Garcia Lambas, Diego

    2017-09-01

    The expanding complex pattern of filaments, walls and voids build the evolving cosmic web with material flowing from underdense on to high density regions. Here, we explore the dynamical behaviour of voids and galaxies in void shells relative to neighbouring overdense superstructures, using the Millenium simulation and the main galaxy catalogue in Sloan Digital Sky Survey data. We define a correlation measure to estimate the tendency of voids to be located at a given distance from a superstructure. We find voids-in-clouds (S-types) preferentially located closer to superstructures than voids-in-voids (R-types) although we obtain that voids within ˜40 h-1 Mpc of superstructures are infalling in a similar fashion independently of void type. Galaxies residing in void shells show infall towards the closest superstructure, along with the void global motion, with a differential velocity component depending on their relative position in the shell with respect to the direction to the superstructure. This effect is produced by void expansion and therefore is stronger for R-types. We also find that galaxies in void shells facing the superstructure flow towards the overdensities faster than galaxies elsewhere at the same relative distance to the superstructure. The results obtained for the simulation are also reproduced for the Sky Survey Data Release data with a linearized velocity field implementation.

  2. Influence of laser-welding and electroerosion on passive fit of implant-supported prosthesis.

    Science.gov (United States)

    Silva, Tatiana Bernardon; De Arruda Nobilo, Mauro Antonio; Pessanha Henriques, Guilherme Elias; Mesquita, Marcelo Ferraz; Guimaraes, Magali Beck

    2008-01-01

    This study investigated the influence of laser welding and electroerosion procedure on the passive fit of interim fixed implant-supported titanium frameworks. Twenty frameworks were made from a master model, with five parallel placed implants in the inter foramen region, and cast in commercially pure titanium. The frameworks were divided into 4 groups: 10 samples were tested before (G1) and after (G2) electroerosion application; and another 10 were sectioned into five pieces and laser welded before (G3) and after (G4) electroerosion application. The passive fit between the UCLA abutment of the framework and the implant was evaluated using an optical microscope Olympus STM (Olympus Optical Co., Tokyo, Japan) with 0.0005mm of accuracy. Statistical analyses showed significant differences between G1 and G2, G1 and G3, G1 and G4, G2 and G4. However, no statistical difference was observed when comparing G2 and G3. These results indicate that frameworks may show a more precise adaptation if they are sectioned and laser welded. In the same way, electroerosion improves the precision in the framework adaptation.

  3. Implant supported overdentures--the Copenhagen experience

    DEFF Research Database (Denmark)

    Gotfredsen, K

    1997-01-01

    included 15 fractures of the ball attachment and 26 episodes of looseness of the matrices holding the screw in place. Patient satisfaction with the treatment of the lower jaw was high although 7 patients found that control of the upper denture was poor following treatment. CONCLUSIONS: When the bone...... and all but two of the implants were longer than 10 mm. For the implant supported overdentures two methods of attachment were used, a bar or a ball. RESULTS: One of 69 fixtures was lost during the 4-5 year observation period. The mean bone loss for all fixtures was less than 0.2 mm per year. Complications...

  4. Classification of delocalization power of global unitary operations in terms of LOCC one-piece relocalization

    Directory of Open Access Journals (Sweden)

    Akihito Soeda

    2010-06-01

    Full Text Available We study how two pieces of localized quantum information can be delocalized across a composite Hilbert space when a global unitary operation is applied. We classify the delocalization power of global unitary operations on quantum information by investigating the possibility of relocalizing one piece of the quantum information without using any global quantum resource. We show that one-piece relocalization is possible if and only if the global unitary operation is local unitary equivalent of a controlled-unitary operation. The delocalization power turns out to reveal different aspect of the non-local properties of global unitary operations characterized by their entangling power.

  5. Quasi-static strength and fractography analysis of two dental implants manufactured by direct metal laser sintering.

    Science.gov (United States)

    Gehrke, Sergio Alexandre; Pérez-Díaz, Leticia; Dedavid, Berenice Anina

    2018-01-30

    New manufacturing methods was developed to improve the tissues integration with the titanium alloy pieces. The present in vitro study was to assess the resistance and fracture mode after applied a quasi-static compressive force on the two dental implants manufactured by direct metal laser sintering. Twenty dental implants manufactured by direct metal laser sintering, using titanium alloy (Ti-6Al-4V) granules in two designs (n = 10 per group): Conventional dental implant (group Imp1) two-piece implant design, where the surgical implant and prosthetic abutment are two separate components and, the one-piece implant (group Imp2), where the surgical implant and prosthetic abutment are one integral piece. All samples were subjected to quasi-static loading at a 30° angle to the implant axis in a universal testing machine. The mean fracture strengths were 1269.2 ± 128.8 N for the group Imp1 and, 1259.5 ± 115.1 N for the group Imp2, without statistical differences (P = .8722). In both groups, the fracture surface does not present crack between the compact core and the superficial (less dense and porous) part of the implants. Based on the measured resistance data for the two implant models manufactured by direct metal laser sintering tested in the present study, we can suggest that they have adequate capacity to withstand the masticatory loads. © 2018 Wiley Periodicals, Inc.

  6. A sectional-splinting technique for impressing multiple implant units by eliminating the use of an open tray

    Directory of Open Access Journals (Sweden)

    Suryakant C. Deogade

    2014-01-01

    Full Text Available Since the inception of root form implant dentistry by P-I Branemark in the early 1980′s, so many technical advances have been put forward by several authors. However, the open tray impression technique is still performed for impressing multiple implant fixtures as it was first described in the original Branemark procedure manual. The most critical aspect for a successful implant-supported restoration is the passive and an accurate fit of superstructures to avoid preload and loading stresses. Splinting impression technique in multiple implants has gained popularity. Auto-polymerizing acrylic resin is among the most routinely practiced splinting material for multiple implant units. However, unfortunately, it exhibits shrinkage, which makes an impression quite inaccurate. This case report presents the solution to minimize the shrinkage of resin by utilizing sectional-splinting technique as advocated in the previous implant literature.

  7. A Novel Computer-Aided Design/Computer-Assisted Manufacture Method for One-Piece Removable Partial Denture and Evaluation of Fit.

    Science.gov (United States)

    Ye, Hongqiang; Li, Xinxin; Wang, Guanbo; Kang, Jing; Liu, Yushu; Sun, Yuchun; Zhou, Yongsheng

    2018-02-15

    To investigate a computer-aided design/computer-aided manufacturing (CAD/CAM) process for producing one-piece removable partial dentures (RPDs) and to evaluate their fits in vitro. A total of 15 one-piece RPDs were designed using dental CAD and reverse engineering software and then fabricated with polyetheretherketone (PEEK) using CAM. The gaps between RPDs and casts were measured and compared with traditional cast framework RPDs. Gaps were lower for one-piece PEEK RPDs compared to traditional RPDs. One-piece RPDs can be manufactured by CAD/CAM, and their fits were better than those of traditional RPDs.

  8. Implant-supported mandibular removable partial dentures: Functional, clinical and radiographical parameters in relation to implant position.

    Science.gov (United States)

    Jensen, Charlotte; Speksnijder, Caroline M; Raghoebar, Gerry M; Kerdijk, Wouter; Meijer, Henny J A; Cune, Marco S

    2017-06-01

    Patients with a Kennedy class I situation often encounter problems with their removable partial denture (RPD). To assess the functional benefits of implant support to RPDs, the clinical performance of the implants and teeth and to determine the most favorable implant position: the premolar (PM) or molar (M) region. Thirty subjects received 2 PM and 2 M implants. A new RPD was made. Implant support was provided 3 months later. In a cross-over model, randomly, 2 implants (PM or M) supported the RPD during 3 months. Masticatory performance was assessed using the mixing ability index (MAI). Clinical and radiographic parameters were assessed. Non-parametric statistical analysis for related samples and post hoc comparisons were performed. Masticatory performance differed significantly between the stages of treatment (P < .001). MAI-scores improved with implant support although the implant position had no significant effect. No complications to the implants or RPD were observed and clinical and radiographical parameters for both implants and teeth were favorable. Higher scores for bleeding on probing were seen for molar implants. Implant support to a Kennedy class I RPD significantly improves masticatory function, regardless of implant position. No major clinical problems were observed. © 2017 Wiley Periodicals, Inc.

  9. Unknown Aspects of Self-Assembly of PbS Microscale Superstructures

    Science.gov (United States)

    Querejeta-Fernández, Ana; Hernández-Garrido, Juan C.; Yang, Hengxi; Zhou, Yunlong; Varela, Aurea; Parras, Marina; Calvino-Gámez, José J.; González-Calbet, Jose M.; Green, Peter F.; Kotov, Nicholas A.

    2012-01-01

    A lot of interesting and sophisticated examples of nanoparticle (NP) self-assembly (SA) are known. From both fundamental and technological standpoints this field requires advancements in three principle directions: a) understanding the mechanism and driving forces of three-dimensional (3D) SA with both nano- and micro-levels of organization; b) understanding of disassembly/deconstruction processes; and c) finding synthetic methods of assembly into continuous superstructures without insulating barriers. From this perspective, we investigated the formation of well-known star-like PbS superstructures and found a number of previously unknown or overlooked aspects that can advance the knowledge of NP self-assembly in these three directions. The primary one is that the formation of large seemingly monocrystalline PbS superstructures with multiple levels of octahedral symmetry can be explained only by SA of small octahedral NPs. We found five distinct periods in the formation PbS hyperbranched stars: 1) nucleation of early PbS NPs with an average diameter of 31 nm; 2) assembly into 100–500 nm octahedral mesocrystals; 3) assembly into 1000–2500 nm hyperbranched stars; 4) assembly and ionic recrystallization into six-arm rods accompanied by disappearance of fine nanoscale structure; 5) deconstruction into rods and cubooctahedral NPs. The switches in assembly patterns between the periods occur due to variable dominance of pattern–determining forces that include vander Waals and electrostatic (charge-charge, dipole-dipole, and polarization) interactions. The superstructure deconstruction is triggered by chemical changes in the deep eutectic solvent (DES) used as the media. PbS superstructures can be excellent models for fundamental studies of nanoscale organization and SA manufacturing of (opto)electronics and energy harvesting devices which require organization of PbS components at multiple scales. PMID:22515512

  10. Mach Number effects on turbulent superstructures in wall bounded flows

    Science.gov (United States)

    Kaehler, Christian J.; Bross, Matthew; Scharnowski, Sven

    2017-11-01

    Planer and three-dimensional flow field measurements along a flat plat boundary layer in the Trisonic Wind Tunnel Munich (TWM) are examined with the aim to characterize the scaling, spatial organization, and topology of large scale turbulent superstructures in compressible flow. This facility is ideal for this investigation as the ratio of boundary layer thickness to test section spanwise extent ratio is around 1/25, ensuring minimal sidewall and corner effects on turbulent structures in the center of the test section. A major difficulty in the experimental investigation of large scale features is the mutual size of the superstructures which can extend over many boundary layer thicknesses. Using multiple PIV systems, it was possible to capture the full spatial extent of large-scale structures over a range of Mach numbers from Ma = 0.3 - 3. To calculate the average large-scale structure length and spacing, the acquired vector fields were analyzed by statistical multi-point methods that show large scale structures with a correlation length of around 10 boundary layer thicknesses over the range of Mach numbers investigated. Furthermore, the average spacing between high and low momentum structures is on the order of a boundary layer thicknesses. This work is supported by the Priority Programme SPP 1881 Turbulent Superstructures of the Deutsche Forschungsgemeinschaft.

  11. The Amount of Wear in Attachment of Implant-Supported Overdentures in Mandible

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    Fariborz Vafaee

    2016-10-01

    Full Text Available Background and objectives: One of the simplest and cheapest attachments for overdentures, is the ball-type attachment, however, keeping it during the first year of prosthesis delivery and after that is one of the main concerns of dentists. The present study aimed to assess the wear of matrix in overdentures attachment supported by one, two and three implants in the mandible. Materials and methods: Thirty edentulous patients were randomly divided into three groups: the first group received a single implant in the midline of the lower mandible, the second group two implants in areas B and D, and the third group three implants in areas B, C, and D. The attachment used in patients’ prosthetic with single and two implants was O-ball/ring attachment and for patients with three implants, the treatment plan was ball bar-supported attachments. After placing the new matrix implant for each patient and obtaining their consent, the matrix wear was measured with CMM (Coordinate Measuring Machine device. To compare matrix wear after six months and one year, measurements were repeated. Data analysis, using ANOVA and multiple comparisons was down by Tukey Test. variance with repeated measures and Tukey test were used to compare the groups two-by-two. P.value less than 0.05 was set statistical significant. SPSS 16 software was used for data analysis. Results: The data obtained from the CMM device showed that the lowest mean matrix wear in the maximum single implant and maximum mean were in group two. Conclusion: Both time and the number of implants had a significant effect on the wear of the O-ring.

  12. The role of prosthetic abutment material on the stress distribution in a maxillary single implant-supported fixed prosthesis

    International Nuclear Information System (INIS)

    Peixoto, Hugo Eduardo; Bordin, Dimorvan; Del Bel Cury, Altair A.; Silva, Wander José da; Faot, Fernanda

    2016-01-01

    Purpose: Evaluate the influence of abutment's material and geometry on stress distribution in a single implant-supported prosthesis. Materials and Methods: Three-dimensional models were made based on tomographic slices of the upper middle incisor area, in which a morse taper implant was positioned and a titanium (Ti) or zirconia (ZrN) universal abutments was installed. The commercially available geometry of titanium (T) and zirconia (Z) abutments were used to draw two models, TM1 and ZM1 respectively, which served as control groups. These models were compared with 2 experimental groups were the mechanical properties of Z were applied to the titanium abutment (TM2) and vice versa for the zirconia abutment (ZM2). Subsequently, loading was simulated in two steps, starting with a preload phase, calculated with the respective friction coefficients of each materials, followed by a combined preload and chewing force. The maximum von Mises stress was described. Data were analyzed by two-way ANOVA that considered material composition, geometry and loading (p 0.05). Conclusion: The screw was the piece most intensely affected, mainly through the preload force, independent of the abutment's material. - Highlights: • The abutment's screw was the most impaired piece of the dental implant system. • The highest stress was located at first thread of the abutment's screw. • The preload is the main factor in the abutment's screw stress. • Abutment configuration and material can have a positive contribution for the stress distribution

  13. ELABORATION OF THE SUPERSTRUCTURE OF THE BULGARIAN HOTEL INDUSTRY

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    Tanya Dabeva

    2010-12-01

    Full Text Available The purpose of the paper is to suggest some terms of reference for the elaboration of the superstructure of the Bulgarian hotel industry. The suggestions are based on the analysis of the superstructure at present. Its capacity, main types of accommodation establishments and their distribution by categories and territory are examined. An analysis is made of some resulting indices such as overnight stays and average stay. The main positive, respectively negative features of the superstructure have been analyzed. Concrete terms of reference have been given in order to overcome the problems specified.

  14. Treatment planning: implant-supported partial overdentures.

    Science.gov (United States)

    Chee, Winston W L

    2005-04-01

    When multiple anterior teeth are missing, many options of replacement are available. Traditionally, the choice was between a fixed or removable prostheses. Today, with the predictability of dental implants, the options of tooth replacement range from removable partial dentures to implant-supported fixed prostheses. The choice of which restoration that will best provide occlusion and esthetics depends on multiple factors including the number and location of missing teeth, the residual ridge form in relation to the replacement teeth, the relationship of the maxillary and mandibular anterior teeth, the condition of teeth adjacent to the edentulous span, the amount of bone available for implant placement, the patients "smile line" and display of teeth, lip support, and financial constraints. When there is minimal loss of the ridge contour, restorations that emerge from the ridge are the most functional and esthetic restorations, adhesive-type fixed partial dentures, conventional fixed partial dentures, and implant-supported restorations can be indicated with the choice of restoration dependent on a risk benefit and cost benefit analysis. When there is a loss of ridge contour due to residual ridge resorption or trauma, the decision becomes more complex as not only does the tooth structure need to be replaced, the ridge form also has to be replaced. (Figures 1 and 2). This can be assessed clinically as illustrated by Figures 1 and 2 where a dis crepancy in arch form and ridge form in relation to the adjacent teeth and/or opposing arch can be observed. Other considerations are lip support and display of the teeth when smiling. This article presents a case and rationale for implant-supported par tial overdentures. Many authors have written on the merits of com plete overdentures. The complete overdenture has proven to be an improvement over conventional complete prostheses with respect to chewing efficiency, patient comfort and satisfaction. In partial edentulism, the

  15. Split-Framework in Mandibular Implant-Supported Prosthesis

    Directory of Open Access Journals (Sweden)

    Danny Omar Mendoza Marin

    2015-01-01

    Full Text Available During oral rehabilitation of an edentulous patient with an implant-supported prosthesis, mandibular flexure must be considered an important biomechanical factor when planning the metal framework design, especially if implants are installed posterior to the interforaminal region. When an edentulous mandible is restored with a fixed implant-supported prosthesis connected by a fixed full-arch framework, mandibular flexure may cause needless stress in the overall restorative system and lead to screw loosening, poor fit of prosthesis, loss of the posterior implant, and patient’s discomfort due to deformation properties of the mandible during functional movements. The use of a split-framework could decrease the stress with a precise and passive fit on the implants and restore a more natural functional condition of the mandible, helping in the longevity of the prosthesis. Therefore, the present clinical report describes the oral rehabilitation of an edentulous patient by a mandibular fixed implant-supported prosthesis with a split-framework to compensate for mandibular flexure. Clinical Significance. The present clinical report shows that the use of a split-framework reduced the risk of loss of the posterior implants or screws loosening with acceptable patient comfort over the period of a year. The split-framework might have compensated for the mandibular flexure during functional activities.

  16. Tardive Dyskinesia, Oral Parafunction, and Implant-Supported Rehabilitation

    Directory of Open Access Journals (Sweden)

    S. Lumetti

    2016-01-01

    Full Text Available Oral movement disorders may lead to prosthesis and implant failure due to excessive loading. We report on an edentulous patient suffering from drug-induced tardive dyskinesia (TD and oral parafunction (OP rehabilitated with implant-supported screw-retained prostheses. The frequency and intensity of the movements were high, and no pharmacological intervention was possible. Moreover, the patient refused night-time splint therapy. A series of implant and prosthetic failures were experienced. Implant failures were all in the maxilla and stopped when a rigid titanium structure was placed to connect implants. Ad hoc designed studies are desirable to elucidate the mutual influence between oral movement disorders and implant-supported rehabilitation.

  17. Tardive Dyskinesia, Oral Parafunction, and Implant-Supported Rehabilitation.

    Science.gov (United States)

    Lumetti, S; Ghiacci, G; Macaluso, G M; Amore, M; Galli, C; Calciolari, E; Manfredi, E

    2016-01-01

    Oral movement disorders may lead to prosthesis and implant failure due to excessive loading. We report on an edentulous patient suffering from drug-induced tardive dyskinesia (TD) and oral parafunction (OP) rehabilitated with implant-supported screw-retained prostheses. The frequency and intensity of the movements were high, and no pharmacological intervention was possible. Moreover, the patient refused night-time splint therapy. A series of implant and prosthetic failures were experienced. Implant failures were all in the maxilla and stopped when a rigid titanium structure was placed to connect implants. Ad hoc designed studies are desirable to elucidate the mutual influence between oral movement disorders and implant-supported rehabilitation.

  18. Fabrication of a Customized Ball Abutment to Correct a Nonparallel Implant Abutment for a Mandibular Implant-Supported Removable Partial Prosthesis: A Case Report

    Directory of Open Access Journals (Sweden)

    Hossein Dasht

    2017-12-01

    Full Text Available Introduction: While using an implant-supported removable partial prosthesis, the implant abutments should be parallel to one another along the path of insertion. If the implants and their attachments are placed vertically on a similar occlusal plane, not only is the retention improved, the prosthesis will also be maintained for a longer period. Case Report: A 65-year-old male patient referred to the School of Dentistry in Mashhad, Iran with complaints of discomfort with the removable partial dentures for his lower mandible. Due to the lack of parallelism in the supporting implants, prefabricated ball abutment could not be used. As a result, a customized ball abutment was fabricated in order to correct the non-parallelism of the implants. Conclusion: Using UCLA abutments could be a cost-efficient approach for the correction of misaligned implant abutments in implant-supported overdentures.

  19. Cryo-transmission electron microscopy of a superstructure of fluid dioleoylphosphatidylcholine (DOPC) membranes

    DEFF Research Database (Denmark)

    Klösgen, B; Helfrich, W

    1997-01-01

    a porous technical membrane. Sampling and cryofixation took place at various times within 3 weeks after the preparation. From the micrographs we infer that the small fraction of vesicles enclosing one another develop passages (connections) between the bilayers. In contrast, the superstructure is basically...... a feature of disconnected membranes. Among its modifications are isolated membrane bends or folds and a grainy membrane texture with a minimal grain spacing of 4-6 nm. In the extruded dispersions the passages and the superstructure seem to be formed mostly within the first day. The fraction of smooth...

  20. PEEK with Reinforced Materials and Modifications for Dental Implant Applications

    Directory of Open Access Journals (Sweden)

    Fitria Rahmitasari

    2017-12-01

    Full Text Available Polyetheretherketone (PEEK is a semi-crystalline linear polycyclic thermoplastic that has been proposed as a substitute for metals in biomaterials. PEEK can also be applied to dental implant materials as a superstructure, implant abutment, or implant body. This article summarizes the current research on PEEK applications in dental implants, especially for the improvement of PEEK surface and body modifications. Although various benchmark reports on the reinforcement and surface modifications of PEEK are available, few clinical trials using PEEK for dental implant bodies have been published. Controlled clinical trials, especially for the use of PEEK in implant abutment and implant bodies, are necessary.

  1. Multi-objective superstructure-free synthesis and optimization of thermal power plants

    International Nuclear Information System (INIS)

    Wang, Ligang; Lampe, Matthias; Voll, Philip; Yang, Yongping; Bardow, André

    2016-01-01

    The merits of superstructure-free synthesis are demonstrated for bi-objective design of thermal power plants. The design of thermal power plants is complex and thus best solved by optimization. Common optimization methods require specification of a superstructure which becomes a tedious and error-prone task for complex systems. Superstructure specification is avoided by the presented superstructure-free approach, which is shown to successfully solve the design task yielding a high-quality Pareto front of promising structural alternatives. The economic objective function avoids introducing infinite numbers of units (e.g., turbine, reheater and feedwater preheater) as favored by pure thermodynamic optimization. The number of feasible solutions found per number of mutation tries is still high even after many generations but declines after introducing highly-nonlinear cost functions leading to challenging MINLP problems. The identified Pareto-optimal solutions tend to employ more units than found in modern power plants indicating the need for cost functions to reflect current industrial practice. In summary, the multi-objective superstructure-free synthesis framework is a robust approach for very complex problems in the synthesis of thermal power plants. - Highlights: • A generalized multi-objective superstructure-free synthesis framework for thermal power plants is presented. • The superstructure-free synthesis framework is comprehensively evaluated by complex bi-objective synthesis problems. • The proposed framework is effective to explore the structural design space even for complex problems.

  2. All-in-one bioprobe devised with hierarchical-ordered magnetic NiCo2O4 superstructure for ultrasensitive dual-readout immunosensor for logic diagnosis of tumor marker.

    Science.gov (United States)

    Dai, Hong; Gong, Lingshan; Zhang, Shupei; Xu, Guifang; Li, Yilin; Hong, Zhensheng; Lin, Yanyu

    2016-03-15

    A new enzyme-free all-in-one bioprobe, consisted of hematin decorated magnetic NiCo2O4 superstructure (ATS-MNS-Hb), was designed for ultrasensitive photoelectrochemical and electrochemical dual-readout immunosensing of carcinoembryonic antigen (CEA) on carbon nanohorns (CNH) support. Herein, the MNS, possessed hierarchical-ordered structure, good porosity and magnetism, acted as nanocarrier to absorb abundant Hb molecular after functionalization, providing a convenient collection means by magnetic control as well as enhanced dual-readout sensing performances. CNH superstructures were employed as support to immobilize abounding captured antibodies, and then as-designed dual mode bioprobe, covalent binding with secondary antibody of CEA, was introduced for ultrasensitive detection of CEA by sandwich immunosensing. Photoelectrochemical response originated from plentiful hematin molecular, a excellent photosensitizer with good visible light harvesting efficiency, absorbed by functionalized porous MNS. The resultant concentration dependant linear calibration range was from 10 fg/mL to 1 ng/mL with ultralow detection limit of 10 fg/mL. For electrochemical process, catalase-like property of MNS was validated, moreover, MNS-Hb hybrid exhibited much higher mimic enzyme catalytic activity and evidently amplified electrocatalytic signal, performing a wide dynamic linear range from 1 ng/mL to 40 ng/mL with low detection limit of 1 ng/mL. Additionally, due to the improved accuracy of dual signals detection, the exact diagnoses of serum samples were gotten by operating resulting dual signals with AND logic system. This work demonstrated the promising application of MNS in developing ultrasensitive, cost-effective and environment friendly dual-readout immunosensor and accurate diagnoses strategy for tumor markers. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. The effect of inter-implant distance on retention and resistance to dislodging forces for mandibular implant-tissue-supported overdentures.

    Directory of Open Access Journals (Sweden)

    Farhad Tabatabaian

    2014-10-01

    Full Text Available The effect of inter-implant distance on retention and resistance of implant-tissue-supported overdentures is lacking in the literature. An in vitro study was performed to evaluate this effect for mandibular implant-tissue-supported overdentures retained by two ball attachments.An acrylic cast of an edentulous mandible was fabricated. Three pairs of implants were symmetrically placed at both sides of the midline. The inter-implant distance was 10, 25, and 35 millimeters in positions A, B and C, respectively. A framework simulating the overdenture was fabricated on the cast. Six attachment housings were placed within the overdenture. For each sample, two ball abutments were screwed onto the implant pairs and two pink nylon inserts were seated in their respective attachment housings. The samples were tested in three groups of 15 (A, B, and C. The testing machine applied tensile dislodging forces and peak loads were measured in three directions: vertical, oblique, and anterior-posterior. A one-way ANOVA followed by Tukey's HSD was used to determine groups that were significantly different. Tests were carried out at 0.05 level of significance.Peak loads for the anterior-posteriorly directed dislodging forces were significantly the highest for group C (P0.05.Inter-implant distance did not affect the vertical retention and oblique resistance of mandibular implant-tissue-supported overdentures; however, it affected anterior-posterior resistance.

  4. Comparative study of longitudinal changes in peri-implant bone microstructure

    International Nuclear Information System (INIS)

    Suzuki, Yusuke; Matsunaga, Satoru; Abe, Shinichi; Ide, Yoshinobu; Usami, Akinobu

    2010-01-01

    The load applied to an implant is directly transmitted to the jaw and is considered to be one of the causes of remodeling of internal trabecular bones. However, the longitudinal changes during loading and the rearrangement of the trabecular bone structure are mostly unknown. The aim of this study was to clarify the changes in internal jaw bone structure longitudinally during natural tooth eruption as well as tooth extraction and post-implantation periods in a dog model by micro computed tomography (micro-CT). Maxillae of 16 male beagle dogs were used in this study. First, 4 dogs with all maxillary molar teeth erupted were euthanized as a control group. Next, 6 teeth consisting of the bilateral maxillary fourth premolars, and first and second molars were extracted from each of the 12 dogs. Then, 4 dogs of the tooth-extracted group were euthanized 3 months after extraction of the teeth. At this time, three implants were inserted in the left side of the maxilla of the remaining 8 dogs, and the superstructures were placed after 3 months. Four of these 8 dogs with implants were euthanized at 3 months and the other 4 at 1 year after placement of the superstructure. Then, the maxillary bone was removed from each dog as a specimen and sequential micro-CT images were taken. After reconstruction of three-dimensional images, morphological and metrical observation of the jaw trabecular bone structure was performed. A decrease of the trabecular bone in the tooth-extracted group was morphologically and morphometrically observed, whereas the implanted group showed thick, rich trabecular bone. Although a longitudinal decrease in the bone tissue volume was recognized both in the tooth-extracted and the implanted groups, the amount was smaller in the implanted group than in the tooth-extracted group. The results suggested that the application of load by implants in the case of tooth loss inhibits resorption of the alveolar bone and prevents thinning of the jaw. (author)

  5. Nilai Pendidikan Dalam Komik One Piece Jilid 1-23 Karya Eiichiro Oda (Sebuah Tinjauan Sosiologi Sastra)

    OpenAIRE

    Furqon, Muhammad Taufiq

    2013-01-01

    Furqon, Muhammad Taufiq. 2013. “Nilai Pendidikan dalam Komik One Piece Jilid 1-23 Karya Eiichiro Oda”. Skripsi S-1 Fakultas Ilmu Budaya Universitas Diponegoro Semarang. Permasalahan dalam penelitian ini adalah komik One Piece dilihat dari bentuknya hanya terdiri dari gambar dan teks, tetapi ada unsur-unsur fiksi terdapat di dalamnya seperti adanya tema, tokoh, latar,dan ada amanat yang ingin disampaikan pengarangnya. Sehingga pemahaman dan pemaknaan terhadapnya mampu memberikan manfaat bagi p...

  6. Influence of implant position on clinical crown length and peri-implant soft tissue dimensions at implant-supported single crowns replacing maxillary central incisors

    DEFF Research Database (Denmark)

    Peng, Min; Fei, Wei; Hosseini, Mandana

    2013-01-01

    The aims of the present study were to evaluate the influence of implant position on clinical crown length and marginal soft tissue dimensions at implant-supported single crowns of maxillary central incisors, and to validate the papilla index score (PIS). Twenty-five patients, who had lost one of ...... abutments and did not necessarily result in an increased crown length. The distal implant papilla heightwas obviously shorter, althoughthe mesial papilla height was similar to thatof the healthy dentition.The papilla index score was tested to be a valid index for papilla fill....

  7. Occlusal wear of provisional implant-supported restorations.

    Science.gov (United States)

    Santing, Hendrik J; Kleverlaan, Cornelis J; Werner, Arie; Feilzer, Albert J; Raghoebar, Gerry M; Meijer, Henny J A

    2015-02-01

    Implant-supported provisional restorations should be resistant to occlusal wear. The purpose of this laboratory study was to evaluate three-body wear of three indirect laboratory composite resins, five chair side bis-acryl resin-based materials, and two chair side methacrylate-based materials used to fabricate provisional implant-supported restorations. The materials were handled and cured according to the manufacturers' instructions. The three-body wear was measured 1 day, 3 days, 7 days, 4 weeks, and 8 weeks after curing using the ACTA wear device. Wear rate decreased significantly after 8 weeks compared with the first day for all tested materials, except for Estenia C&B. The three-body wear of two indirect laboratory composite resins, that is, Estenia C&B and Solidex, was significantly less compared with all other tested materials used for fabricating provisional implant-supported restorations. Of the chair side materials, the wear rate of Protemp Crown Paste was significantly less compared with the others materials used to fabricate chair side provisional implant-supported restorations. The methacrylate-based materials, Temdent Classic and Trim, showed extreme high wear rates. Based on the results of this laboratory study on long-term wear, the use of indirect composite resin is preferred over chair side methacrylate-based materials when the provisional implant-supported restoration has to be in service for a long period of time. Of the investigated materials, only Estenia C&B and Solidex showed wear rate comparable with posterior resin composites. © 2013 Wiley Periodicals, Inc.

  8. Elements of implant-supported rehabilitation planning in patients with bruxism.

    Science.gov (United States)

    Sarmento, Hugo Ramalho; Dantas, Raquel Venâncio Fernandes; Pereira-Cenci, Tatiana; Faot, Fernanda

    2012-11-01

    The rehabilitation of partial or completely edentulous patients with implant-supported prostheses has been widely used, achieving high success rates. However, many studies consider the presence of bruxism as a contraindication for this treatment modality. The purpose of this study was to revise the literature and identify risk factors in implant-supported rehabilitation planning in subjects with bruxism. Available literature was searched through Medline, with no time limit, including only studies in English. Topics discussed were etiology of bruxism and its implications on dental implants, biomechanical considerations regarding the overload on dental implants, and methods to prevent the occurrence of overloads in implant-supported prostheses. The rehabilitation of bruxers using implant-supported prostheses, using implants with adequate length and diameter, as well as proper positioning seems to be a reliable treatment, with reduced risks of failure. Bruxism control through the use of a nightguard by rigid occlusal stabilization appliance relieved in the region of implants is highly indicated. Although it is clear that implant-supported rehabilitation of patients with bruxism requires adequate planning and follow-up, well-designed randomized controlled trials are needed to provide reliable evidence on the long-term success of this treatment modality.

  9. Investigational Clinical Trial of a Prototype Optoelectronic Computer-Aided Navigation Device for Dental Implant Surgery.

    Science.gov (United States)

    Jokstad, Asbjørn; Winnett, Brenton; Fava, Joseph; Powell, David; Somogyi-Ganss, Eszter

    New digital technologies enable real-time computer-aided (CA) three-dimensional (3D) guidance during dental implant surgery. The aim of this investigational clinical trial was to demonstrate the safety and effectiveness of a prototype optoelectronic CA-navigation device in comparison with the conventional approach for planning and effecting dental implant surgery. Study participants with up to four missing teeth were recruited from the pool of patients referred to the University of Toronto Graduate Prosthodontics clinic. The first 10 participants were allocated to either a conventional or a prototype device study arm in a randomized trial. The next 10 participants received implants using the prototype device. All study participants were restored with fixed dental prostheses after 3 (mandible) or 6 (maxilla) months healing, and monitored over 12 months. The primary outcome was the incidence of any surgical, biologic, or prosthetic adverse events or device-related complications. Secondary outcomes were the incidence of positioning of implants not considered suitable for straightforward prosthetic restoration (yes/no); the perception of the ease of use of the prototype device by the two oral surgeons, recorded by use of a Likert-type questionnaire; and the clinical performance of the implant and superstructure after 1 year in function. Positioning of the implants was appraised on periapical radiographs and clinical photographs by four independent blinded examiners. Peri-implant bone loss was measured on periapical radiographs by a blinded examiner. No adverse events occurred related to placing any implants. Four device-related complications led to a switch from using the prototype device to the conventional method. All implants placed by use of the prototype device were in a position considered suitable for straightforward prosthetic restoration (n = 21). The qualitative evaluation by the surgeons was generally positive, although ergonomic challenges were identified

  10. Autoinflation Leading to Failure of Two-Piece Ambicor Implantable Penile Prosthesis: An Outcome from a Methodical Treatment of Recalcitrant Stuttering Priapism

    Directory of Open Access Journals (Sweden)

    R. Charles Welliver

    2014-01-01

    Full Text Available Introduction. We present the case of a patient who received a two-piece Ambicor penile prosthesis for idiopathic recurrent “stuttering” priapism refractory to other treatment options. The patient returned unable to deflate the device due to an interesting anatomically induced mechanical failure. Aims. To describe the method and findings of this inflatable prosthesis failure. Results. Prosthesis failure occurred due to restrictive corporal diameter and the unique characteristics of fluid reservoir location in the two-piece inflatable prosthesis. The patient was successfully converted to a semirigid prosthesis with resolution of the pain that was due to his prosthesis autoinflation. Conclusion. Stuttering priapism remains a challenging clinical problem. Penile implantation is a reasonable long-term solution in a patient refractory to less invasive options. In patients with fibrotic corpora, a malleable device should be considered (at least temporarily if unable to dilate comfortably to 13 mm.

  11. Prosthodontic maintenance of overdentures on zirconia implants: 1-year results of a randomized controlled trial.

    Science.gov (United States)

    Osman, Reham B; Ma, Sunyoung

    2014-01-01

    The purpose of this study was to determine the prosthodontic outcomes of one-piece zirconia implants and their attachment systems in edentulous participants with maxillary and mandibular overdentures after 1 year of a randomized controlled trial. Random allocation of 24 edentulous participants (age range: 45 to 86 years) into titanium (control) or zirconia (test) groups using onepiece implants and a planned unsplinted prosthodontic design was performed. Four maxillary implants (one midpalatal; three anterior crestal) and three mandibular implants (one midsymphyseal; two bilateral distal) were conventionally loaded with the overdentures. Similar attachment systems were used throughout: ball abutment-type patrices (diameter: 2.25 to 3.1 mm as part of the one-piece implants) and custommade plastic matrices (with or without metal housings depending on the patrix size). Prosthodontic outcomes were documented during the first year of the clinical trial. Following three deaths and two dropouts, there were 19 participants who were available at the 1-year recall. Of these participants, 3 had early maxillary implant failure and had to be converted to conventional maxillary complete dentures opposing mandibular implant overdentures. There were 79 maintenance events, 34 in the titanium (control) group and 45 in the zirconia (test) group. Patrix loss occurred as a result of three zirconia implant fractures (one mandibular and two crestal maxillary implants). Maintenance events were principally the replacement of matrices and overdenture fracture. Although relines and replacement overdentures also occurred, overall there were no significant differences in prosthodontic maintenance between the control and test groups. A six-field prosthodontic-success analysis table showed no statistically significant difference between the two groups; however, 50% of participants in each group were allocated to the retreatment (repair) field, which produced a low prosthodontic success rate

  12. Peri-Implant Strain in an In Vitro Model.

    Science.gov (United States)

    Hussaini, Souheil; Vaidyanathan, Tritala K; Wadkar, Abhinav P; Quran, Firas A Al; Ehrenberg, David; Weiner, Saul

    2015-10-01

    An in vitro experimental model was designed and tested to determine the influence that peri-implant strain may have on the overall crestal bone. Strain gages were attached to polymethylmethacrylate (PMMA) models containing a screw-type root form implant at sites 1 mm from the resin-implant interface. Three different types of crown superstructures (cemented, 1-screw [UCLA] and 2-screw abutment types) were tested. Loading (1 Hz, 200 N load) was performed using a MTS Mechanical Test System. The strain gage data were stored and organized in a computer for statistical treatment. Strains for all abutment types did not exceed the physiological range for modeling and remodeling of cancellous bone, 200-2500 με (microstrain). For approximately one-quarter of the trials, the strain values were less than 200 με the zone for bone atrophy. The mean microstrain obtained was 517.7 με. In conclusion, the peri-implant strain in this in vitro model did not exceed the physiologic range of bone remodeling under axial occlusal loading.

  13. A novel ethanol templating synthesis of ordered lamellar superstructured crystalline zirconia

    International Nuclear Information System (INIS)

    Liu Chao; Wang Bin; Ji Xiujie; Zhao Shanshan; Wu Jie; Jia Jianlong; Ma Dongxia

    2012-01-01

    Soft template technique has attracted great interest, because it is a facile, inexpensive and efficient synthesis strategy for ordered superstructural systems. Here, a novel ethanol template was used to synthesize the ordered lamellar superstructured crystalline zirconia (Lα-ZrO 2 ) without post-treatments and surfactants. ZrOCl 2 and NaOH were served as Zr source and precipitant, respectively. XRD analysis showed that Lα-ZrO 2 is crystalline. XPS spectra indicated the physical adsorption of ethanol molecules in Lα-ZrO 2 . TEM further observed and proved the 1.36-nm period of superstructure detected and calculated by SAXRD (1.35 nm), which is composed of 0.68-nm thick ZrO 2 and pore alternatively. In contrast, the template-free ZrO 2 (TF-ZrO 2 ) presents no superstructure and is poorly crystallized. As a soft template, ethanol presents the roles of (i) inducing the growth of zirconia layers, (ii) directing the self-assembly of ordered lamellar superstructure, and (iii) decreasing the crystallization temperature. The possible mechanism of ethanol serving as a soft template was proposed and discussed in thermodynamics.

  14. Implant Supported Fixed Restorations versus Implant Supported Removable Overdentures: A Systematic Review

    Science.gov (United States)

    Selim, Khaled; Ali, Sherif; Reda, Ahmed

    2016-01-01

    AIM: The aim of this study is to systematically evaluate and compare implant retained fixed restoration versus implant retained over denture. MATERIAL AND METHODS: Search was made in 2 databases including PubMed and PubMed Central. Title and abstract were screened to select studies comparing implant retained fixed restorations versus implant retained removable overdentures. Articles which did not follow the inclusion criteria were excluded. Included papers were then read carefully for a second stage filter, this was followed by manual searching of bibliography of selected articles. RESULTS: The search resulted in 5 included papers. One study evaluated the masticatory function, while the other 4 evaluated the patient satisfaction. Two of them used Visual Analogue Scale (VAS) as a measurement tool, while the other two used VAS and Categorical Scales (CAT). Stability, ability to chew, ability to clean, ability to speak and esthetics were the main outcomes of the 4 included papers. CONCLUSION: Conflicting results was observed between the fixed and removable restorations. PMID:28028423

  15. Retrofitting the Superstructure of a Large Passenger Ship Using Composites – A Demonstration

    DEFF Research Database (Denmark)

    Karatzas, Vasileios; Hjørnet, Niels; Berggreen, Christian

    2015-01-01

    In this work, the superstructure of a RoPax ferry has been redesigned using composite materials and the new design has been compared to the existing steel superstructure from a structural perspective. To this end, FE models have been developed and the superstructures have been subjected to loadin...

  16. Zinc phosphate as a definitive cement for implant-supported crowns and fixed dentures

    Directory of Open Access Journals (Sweden)

    Flanagan D

    2017-11-01

    Full Text Available Dennis Flanagan Private Practice, Willimantic, CT, USA Abstract: Implant-supported dental prostheses can be retained by a screw or cement. Implant-supported fixed partial dentures have a passive fit. A passive fit means there is an internal gap between the abutment surface and the intaglio of the retainer to insure that there is no lateral pressure on the supporting implants or friction upon seating of the prosthesis. This gap is filled with cement for retention of the prosthesis. Any lateral pressure may cause marginal bone loss or periimplantitis. Also, there is usually a microscopic gap at the margin of a crown retainer that exposes the cement to oral fluids. The solubility of zinc phosphate (ZOP cement is a definite liability due to the risk for cement dissolution. In fixed prostheses, the dissolution of the cement of one or more retainers would cause a transfer of the occlusal load to the retained unit(s. The resulting rotation and lifting of the cement-retained implants from occlusal and parafunctional loads could cause loss of osseointegration of the abutment-retained implant(s. ZOP cement may not be indicated for implant-supported fixed partial dentures or splints. Cement dissolution in single unit probably only involves re-cementation, if the patient does not swallow or aspirate the crown. Keywords: passive fit, retention, film thickness, fixed, marginal gap 

  17. Scleral fixation of a single-piece multifocal intraocular lens.

    Science.gov (United States)

    Can, Ertugrul; Basaran, M Resat; Gül, Adem

    2013-01-01

    We describe an ab interno technique for injector implantation of a one-piece multifocal intraocular lens (IOL). Transscleral fixation of multifocal posterior chamber IOL implantation using an injector with ab interno technique was performed in an eye of a 9-year-old girl who had undergone pars plana lensectomy 2 years before for bilateral lens subluxation with unknown etiology. No major complications were encountered during a 3-month follow-up of the patient and excellent centration was observed during the follow-up period. Her preoperative best spectacle-corrected distance visual acuity of 20/32 improved to uncorrected distance visual acuity of 20/25. Closed-loop design of IOL served the function of eyelets and position of the IOL was provided using only a 2-point fixation. Intraoperative position adjustment of the IOL provided an excellent centralization of multifocal IOL.

  18. Super-structure and building performance

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-11-01

    Full Text Available The super-structure consists predominantly of the load- and no-load-bearing walls-including all doors and windows and suspended floor slabs. The building envelope plays a significant role in the performance of a building, especially with regard...

  19. Fracture of Reduced-Diameter Zirconia Dental Implants Following Repeated Insertion.

    Science.gov (United States)

    Karl, Matthias; Scherg, Stefan; Grobecker-Karl, Tanja

    Achievement of high insertion torque values indicating good primary stability is a goal during dental implant placement. The objective of this study was to evaluate whether or not two-piece implants made from zirconia ceramic may be damaged as a result of torque application. A total of 10 two-piece zirconia implants were repeatedly inserted into polyurethane foam material with increasing density and decreasing osteotomy size. The insertion torque applied was measured, and implants were checked for fractures by applying the fluorescent penetrant method. Weibull probability of failure was calculated based on the recorded insertion torque values. Catastrophic failures could be seen in five of the implants from two different batches at insertion torques ranging from 46.0 to 70.5 Ncm, while the remaining implants (all belonging to one batch) survived. Weibull probability of failure seems to be low at the manufacturer-recommended maximum insertion torque of 35 Ncm. Chipping fractures at the thread tips as well as tool marks were the only otherwise observed irregularities. While high insertion torques may be desirable for immediate loading protocols, zirconia implants may fracture when manufacturer-recommended insertion torques are exceeded. Evaluating bone quality prior to implant insertion may be useful.

  20. Masseter muscle fatigue during sustained clenching in subjects with complete dentures, implant-supported prostheses, and natural teeth.

    Science.gov (United States)

    Jacobs, R; van Steenberghe, D

    1993-03-01

    A sustained submaximal (50%) clenching effort was performed in four patient groups to establish whether implant-supported prosthetic reconstructions influence myoelectrical signal parameters. The first group consisted of patients with natural teeth in both jaws. The other three groups consisted of patients who were edentulous in both jaws: one group had complete dentures; one had an overdenture in the mandible on two implants connected by a bar; and the third had an implant-supported fixed prosthesis in either the maxilla or the mandible. Surface electromyography indicated an increased myoelectrical output level that paralleled a higher bite force level for implant-supported reconstructions compared with complete dentures. Power spectrum analysis revealed a downward shift of the mean power frequency during sustained clenching in all groups except the implant-supported fixed prosthesis. The absence of a spectral shift in the latter group probably reflected a fear of biting too hard and fracturing the prosthesis.

  1. The smaller the pieces the healthier their consumption

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg; Skov, Katrine Lund; Schmidt, Karsten

    the snack breaks. The hypothesis was that consumers could be nudged to healthier food choices by improving accessibility to sliced apples and make a “healthier” cake portion (small) the default. The sample consisted of 391 people attending a congress in Copenhagen, Denmark. People were divided in two groups...... for snacking during breaks, and were informed that this was for logistic reasons. Two snack tables were set up, one with normal sized pieces of cake (usual sizes provided by the caterer) as well as whole apples (control N=189), and a table with halved pieces of cake as well as apples served in quarter pieces....... This pilot study supports the hypothesis that the presentation of snacks plays an important role in the consumption of fruit and cake among Danish adults. Further, it suggests that such approach could become a supportive tool set for achieving PHN objectives....

  2. Experimental Investigation of a Self-Sensing Hybrid GFRP-Concrete Bridge Superstructure with Embedded FBG Sensors

    OpenAIRE

    Wang, Yanlei; Li, Yunyu; Ran, Jianghua; Cao, Mingmin

    2012-01-01

    A self-sensing hybrid GFRP-concrete bridge superstructure, which consists of two bridge decks and each bridge deck is comprised of four GFRP box sections combined with a thin layer of concrete in the compression zone, was developed by using eight embedded FBG sensors in the top and bottom flanges of the four GFRP box sections at midspan section of one bridge deck along longitudinal direction, respectively. The proposed self-sensing hybrid bridge superstructure was tested in 4-point loading to...

  3. Mandibular implant-supported overdentures: attachment systems, and number and locations of implants--Part I.

    Science.gov (United States)

    Warreth, Abdulhadi; Alkadhimi, Aslam Fadel; Sultan, Ahmed; Byrne, Caroline; Woods, Edel

    2015-01-01

    The use of dental implants in replacing missing teeth is an integral part of restorative dental treatment. Use of conventional complete dentures is associated with several problems such as lack of denture stability, support and retention. However, when mandibular complete dentures were used with two or more implants, an improvement in the patients' psychological and social well-being could be seen. There is general consensus that removable implant-supported overdentures (RISOs) with two implants should be considered as the first-choice standard of care for an edentulous mandible. This treatment option necessitates the use of attachment systems that connect the complete denture to the implant. Nevertheless, each attachment system has its inherent advantages and disadvantages, which should be considered when choosing a system. The first part of this article provides an overview on options available to restore the mandibular edentulous arch with dental implants. Different types of attachment systems, their features and drawbacks are also reviewed.

  4. Topotactic transformations of superstructures: from thin films to two-dimensional networks to nested two-dimensional networks.

    Science.gov (United States)

    Guo, Chuan Fei; Cao, Sihai; Zhang, Jianming; Tang, Haoying; Guo, Shengming; Tian, Ye; Liu, Qian

    2011-06-01

    Design and synthesis of super-nanostructures is one of the key and prominent topics in nanotechnology. Here we propose a novel methodology for synthesizing complex hierarchical superstructures using sacrificial templates composed of ordered two-dimensional (2D) nanostructures through lattice-directed topotactic transformations. The fabricated superstructures are nested 2D orthogonal Bi(2)S(3) networks composed of nanorods. Further investigation indicates that the lattice matching between the product and sacrificial template is the dominant mechanism for the formation of the superstructures, which agrees well with the simulation results based on an anisotropic nucleation and growth analysis. Our approach may provide a promising way toward a lattice-directed nonlithographic nanofabrication technique for making functional porous nanoarchitectures and electronic devices. © 2011 American Chemical Society

  5. A novel ethanol templating synthesis of ordered lamellar superstructured crystalline zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Liu Chao, E-mail: liuchao_tj@yahoo.com; Wang Bin [Key Laboratory for New Type of Functional Materials in Hebei Province, Hebei University of Technology (China); Ji Xiujie, E-mail: jxjchem@yahoo.com [State Key Laboratory of Hollow Fiber Membrane Materials and Processes, Tianjin Polytechnic University (China); Zhao Shanshan; Wu Jie; Jia Jianlong; Ma Dongxia [Key Laboratory for New Type of Functional Materials in Hebei Province, Hebei University of Technology (China)

    2012-03-15

    Soft template technique has attracted great interest, because it is a facile, inexpensive and efficient synthesis strategy for ordered superstructural systems. Here, a novel ethanol template was used to synthesize the ordered lamellar superstructured crystalline zirconia (L{alpha}-ZrO{sub 2}) without post-treatments and surfactants. ZrOCl{sub 2} and NaOH were served as Zr source and precipitant, respectively. XRD analysis showed that L{alpha}-ZrO{sub 2} is crystalline. XPS spectra indicated the physical adsorption of ethanol molecules in L{alpha}-ZrO{sub 2}. TEM further observed and proved the 1.36-nm period of superstructure detected and calculated by SAXRD (1.35 nm), which is composed of 0.68-nm thick ZrO{sub 2} and pore alternatively. In contrast, the template-free ZrO{sub 2} (TF-ZrO{sub 2}) presents no superstructure and is poorly crystallized. As a soft template, ethanol presents the roles of (i) inducing the growth of zirconia layers, (ii) directing the self-assembly of ordered lamellar superstructure, and (iii) decreasing the crystallization temperature. The possible mechanism of ethanol serving as a soft template was proposed and discussed in thermodynamics.

  6. In vitro comparative analysis of the fit of gold alloy or commercially pure titanium implant-supported prostheses before and after electroerosion.

    Science.gov (United States)

    Sartori, Ivete Aparecida de Mattias; Ribeiro, Ricardo Faria; Francischone, Carlos Eduardo; de Mattos, Maria da Gloria Chiarello

    2004-08-01

    For implant-supported prostheses, passive fit is critical for the success of rehabilitation, especially when alternative materials are used. The purpose of this study was to compare interfacial fit of implant-supported prostheses cast in titanium to those cast in gold alloy. Five 3-unit fixed partial dentures were fabricated in gold alloy (Degudent U) as 1-piece castings, and 5 others were similarly cast in commercially pure titanium (Grade 1). The interfacial gaps between the prostheses and the abutments were evaluated with an optical microscope, before and after electroerosion. Readings were made with both screws tightened (10 N.cm torque), and with only 1 side tightened, so as to also evaluate the passive fit of the prostheses. Data were compared statistically by 2-way analysis of variance and the post hoc Tukey multiple range test (alpha=.05). Before electroerosion, the interfacial gaps for the 1-piece prostheses were significantly smaller (Pelectroerosion procedure significantly (Pelectroerosion did not present significant differences when the side opposite the tightened side was analyzed, but the gold alloy group showed better fit when the tightened side was analyzed (12.8 +/- 1.4 microm for gold alloy; 29.6 +/- 4.4 microm for titanium) and when both screws were tightened (5.4 +/- 2.3 microm for gold alloy; 16.1 +/- 5.5 microm for titanium). Cast titanium prostheses, despite showing larger interfacial gaps between the prosthesis and abutment than those obtained with gold alloy, had improved fit after being subjected to electroerosion.

  7. Clinical outcomes of immediate/early loading of dental implants. A literature review of recent controlled prospective clinical studies.

    Science.gov (United States)

    Sennerby, L; Gottlow, J

    2008-06-01

    Two previous reviews have evaluated the clinical outcomes of immediate/early loading of dental implants based on studies published until 2005.(1,2) The aim of the present paper was to review controlled clinical studies on the subject published since 2005 including at least 10 patients in each group followed for at least one year in function. Six comparative studies were found and none of these showed any differences in survival rates or marginal bone loss after one to five years. Most authors used specified inclusion criteria to avoid known risk factors such as soft bone, short implants and bruxism. Data from one randomized study in the edentulous maxilla showed no differences between early and delayed loading in consecutive clinical routine cases including short implants and soft bone. Three additional studies comparing different surfaces or implant designs under immediate loading were reviewed. No differences between implants with a moderately rough or smooth surface topography were observed. The data add to the previous bulk of evidence that various designs of implants can be loaded shortly after their placement in both the mandible and the maxilla. However, one study reported on marginal bone loss around a novel one-piece implant design leading to implant failure which was not seen for control two-piece implants.(3).

  8. Satisfaction and Clinical Outcomes Among Patients with Immediately Loaded Mandibular Overdentures Supported by One or Two Dental Implants: Results of a 5-Year Prospective Randomized Clinical Trial.

    Science.gov (United States)

    Kronstrom, Mats; Davis, Ben; Loney, Robert; Gerrow, Jack; Hollender, Lars

    The purpose of this study was to evaluate patient satisfaction and clinical outcomes among subjects with mandibular overdentures supported by one or two immediately placed dental implants 5 years after loading. Thirty-six subjects (16 men and 20 women) received one or two dental implants in the anterior mandible, and all implants were loaded the day of surgery. Subjects were scheduled for follow-up 3-, 6-, and 12 months after implant placement and thereafter annually for 4 more years. Patient satisfaction scores were measured with the Oral Health Impact Profile-EDENT (OHIPEDENT) questionnaire. Seventeen subjects (7 male and 10 female) with a mean age of 59.4 years (range, 44 to 74 years) were available for the 5-year follow-up examination. Nine subjects with 10 failing implants were excluded during the first year and nine subjects were lost to follow-up. No implants failed between the 12- and 60-month follow-up examinations, and the need for denture maintenance was low. Mean peri-implant bone change was 0.92 mm, and the Spearman test failed to show correlation between the insertion torque value and implant stability quotient. Patient satisfaction scores increased significantly when compared with baseline values and continued to be high for both groups, with no significant differences. Ten implants in nine subjects failed early, but no failures were observed after the 12-month examination. No significant differences were found between subjects in the two groups with respect to implant survival rates and peri-implant bone loss, and patient satisfaction scores continued to be high. Although patient satisfaction and implant success were high during the 12- to 60-month period, the results should be interpreted with caution because of the high number of failing implants and patients lost to follow-up. More research is needed to study outcomes of treatment with immediately loaded mandibular implant overdentures.

  9. Superstructure optimization of biodiesel production from microalgal biomass

    DEFF Research Database (Denmark)

    Rizwan, Muhammad; Lee, Jay H.; Gani, Rafiqul

    2013-01-01

    In this study, we propose a mixed integer nonlinear programming (MINLP) model for superstructure based optimization of biodiesel production from microalgal biomass. The proposed superstructure includes a number of major processing steps for the production of biodiesel from microalgal biomass...... for the production of biodiesel from microalgae. The proposed methodology is tested by implementing on a specific case study. The MINLP model is implemented and solved in GAMS using a database built in Excel. The results from the optimization are analyzed and their significances are discussed....

  10. Fracture Resistance and Mode of Failure of Ceramic versus Titanium Implant Abutments and Single Implant-Supported Restorations.

    Science.gov (United States)

    Sghaireen, Mohd G

    2015-06-01

    The material of choice for implant-supported restorations is affected by esthetic requirements and type of abutment. This study compares the fracture resistance of different types of implant abutments and implant-supported restorations and their mode of failure. Forty-five Oraltronics Pitt-Easy implants (Oraltronics Dental Implant Technology GmbH, Bremen, Germany) (4 mm diameter, 10 mm length) were embedded in clear autopolymerizing acrylic resin. The implants were randomly divided into three groups, A, B and C, of 15 implants each. In group A, titanium abutments and metal-ceramic crowns were used. In group B, zirconia ceramic abutments and In-Ceram Alumina crowns were used. In group C, zirconia ceramic abutments and IPS Empress Esthetic crowns were used. Specimens were tested to failure by applying load at 130° from horizontal plane using an Instron Universal Testing Machine. Subsequently, the mode of failure of each specimen was identified. Fracture resistance was significantly different between groups (p Empress crowns supported by zirconia abutments had the lowest fracture loads (p = .000). Fracture modes of metal-ceramic crowns supported by titanium abutments included screw fracture and screw bending. Fracture of both crown and abutment was the dominant mode of failure of In-Ceram/IPS Empress crowns supported by zirconia abutments. Metal-ceramic crowns supported by titanium abutments were more resistant to fracture than In-Ceram crowns supported by zirconia abutments, which in turn were more resistant to fracture than IPS Empress crowns supported by zirconia abutments. In addition, failure modes of restorations supported by zirconia abutments were more catastrophic than those for restorations supported by titanium abutments. © 2013 Wiley Periodicals, Inc.

  11. Management of sulcus-fixated single-piece intraocular lens-induced pigmentary glaucoma with 3-piece IOL exchange.

    Science.gov (United States)

    Rabie, Hossein Mohammad; Esfandiari, Hamed; Rikhtegar, Mohammad Hassan; Hekmat, Vahid

    2018-02-01

    To describe our experience with exchanging sulcus-fixated single-piece intraocular lens (IOL) with 3-piece IOLs for management of pigmentary glaucoma. In this retrospective study, records of patients who underwent sulcus-fixated single-piece IOL exchanged with 3-piece IOLs were retrieved, and demographic and baseline data of patients, type of IOL, pre- and post-IOL exchange BCVA, IOP, number of anti-glaucoma medications, and optic nerve head examination were documented. Baseline and final examinations were analyzed and compared. Mean age of the patients was 59 ± 10 years, and 5 (41.6%) were female. Mean interval between primary cataract extraction operation and IOL exchange was 17 ± 5 months. Nine patients received in sulcus implantation of Alcon SA60AT, and three patients had SN60WF model at the end of primary surgery. BCVA changed insignificantly from 0.06 ± 0.06 logMAR to 0.06 ± 0.06 after IOL exchange. (P = 0.22) IOP was controlled in 8 cases (66.6%), but four cases (33.3%) needed glaucoma surgery to further control glaucoma condition. IOP decreased significantly from preoperative 17 ± 3 to 14 ± 1 mmHg postoperatively. Patients with advanced age and higher baseline IOP were more likely to undergo glaucoma surgery after IOL exchange. (P = 0.07 and 0.00, respectively). single-piece IOL exchange with 3-piece IOL dramatically decreases pigment release and reduces IOP. Those with advanced age and higher IOP are less likely to respond to IOL exchange and may need glaucoma surgery to control high intraocular pressure.

  12. Interface magnons. Magnetic superstructure

    International Nuclear Information System (INIS)

    Djafari-Rouhani, B.; Dobrzynski, L.

    1975-01-01

    The localized magnons at an interface between two Heisenberg ferromagnets are studied with a simple model. The effect of the coupling at the interface on the existence condition for the localized modes, the dispersion laws and the possible occurrence of magnetic superstructures due to soft modes are investigated. Finally a comparison is made with the similar results obtained for interface phonons [fr

  13. Sand moulds milling for one-of-a-kind pieces

    Science.gov (United States)

    Rodríguez, A.; Calleja, A.; Olvera, D.; Peñafiel, F. J.; López de Lacalle, L. N.

    2012-04-01

    Time to market is a critical measurement for today's foundry market. Combining 3D digitizing and sand blocks milling is possible to reduce this time. Avoiding the use of a wood pattern, this technique is useful for art pieces or unique parts, when only one component is necessary. The key of the proposed methodology is to achieve enough tool life with conventional tool qualities, avoiding the risk of sand destruction or damage. A special study of tool wear is presented in this work, studying different tool materials and different sand types. Two examples of unique parts are also presented in this work following the proposed methodology in order to reduce time and cost for the rapid reproduction of very short batches.

  14. Fabricating a Mandibular Implant Supported Overdenture with a Suspended Framework

    OpenAIRE

    Ahuja, Swati; Jain, Vinay; Cagna, David; Wicks, Russell

    2012-01-01

    The introduction of implant-supported overdentures as a clinical alternative has improved the quality of life of the edentulous population. Implant-supported overdentures have diminished many of the problems associated with conventional dentures by providing improved retention, stability, function, esthetics and physical and emotional health. Greater support and stability of the implant borne prosthesis is associated with improved bite force and oral function for overdentures when compared to...

  15. Enhanced fullerene–Au(111 coupling in (2√3 × 2√3R30° superstructures with intermolecular interactions

    Directory of Open Access Journals (Sweden)

    Michael Paßens

    2015-06-01

    Full Text Available Disordered and uniform (2√3 × 2√3R30° superstructures of fullerenes on the Au(111 surface have been studied using scanning tunneling microscopy and spectroscopy. It is shown that the deposition and growth process of a fullerene monolayer on the Au(111 surface determine the resulting superstructure. The supply of thermal energy is of importance for the activation of a Au vacancy forming process and thus, one criterion for the selection of the respective superstructure. However, here it is depicted that a vacancy–adatom pair can be formed even at room temperature. This latter process results in C60 molecules that appear slightly more bright in scanning tunnelling microscopy images and are identified in disordered (2√3 x 2√3R30° superstructures based on a detailed structure analysis. In addition, these slightly more bright C60 molecules form uniform (2√3 x 2√3R30° superstructures, which exhibit intermolecular interactions, likely mediated by Au adatoms. Thus, vacancy–adatom pairs forming at room temperature directly affect the resulting C60 superstructure. Differential conductivity spectra reveal a lifting of the degeneracy of the LUMO and LUMO+1 orbitals in the uniform (2√3 x 2√3R30° superstructure and in addition, hybrid fullerene–Au(111 surface states suggest partly covalent interactions.

  16. 46 CFR 108.133 - Hull superstructure, structural bulkheads, decks, and deckhouses.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Hull superstructure, structural bulkheads, decks, and deckhouses. 108.133 Section 108.133 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A... Protection § 108.133 Hull superstructure, structural bulkheads, decks, and deckhouses. Each hull...

  17. Within-Subject Comparison of Maxillary Implant-Supported Overdentures with and without Palatal Coverage.

    Science.gov (United States)

    Zembic, Anja; Tahmaseb, Ali; Wismeijer, Daniel

    2015-06-01

    The purpose of this study was to compare patient-reported outcomes for maxillary implant-supported overdentures with and without palatal coverage. Twenty-one maxillary edentulous patients (six women, 15 men) were included. In total, 42 implants were inserted in the anterior maxilla. All patients received implant-supported overdentures on two retentive anchors with palatal coverage for 2 months. Thereafter, patient satisfaction was assessed by means of questionnaires capturing the oral health impact profile (OHIP) on functional limitation, physical pain, psychological discomfort, physical, psychological and social disability, and handicap. Additionally, cleaning ability, general satisfaction, speech, comfort, esthetics, stability, and chewing ability were rated. Subsequently, palatal coverage was reduced, and the patients wore the overdentures for another 2 months. Patient satisfaction was obtained in the same way as above, and the evaluated parameters were compared for the two overdenture designs. There were no significant differences between implant-supported overdentures with and without palatal coverage for any of the OHIP domains. The evaluation of additional parameters revealed significantly higher patient satisfaction for esthetics (mean difference 8.8 mm ± 24.6) and taste (mean difference 28.4 mm ± 29.9) without palatal coverage, p overdentures supported by two implants were equally satisfactory with and without palatal coverage. © 2013 Wiley Periodicals, Inc.

  18. Effects of Food Texture on Three-Dimensional Loads on Implants During Mastication Based on In Vivo Measurements.

    Science.gov (United States)

    Yoda, Nobuhiro; Ogawa, Toru; Gunji, Yoshinori; Vanegas, Juan R; Kawata, Tetsuo; Sasaki, Keiichi

    2016-08-01

    The mechanisms by which the loads exerted on implants that support prostheses are modulated during mastication remain unclear. The purpose of this study was to evaluate the effects of food texture on 3-dimensional loads measured at a single implant using a piezoelectric transducer. Two subjects participated in this study. The transducer and the experimental superstructure, which had been adjusted to the subject's occlusal scheme, were attached to the implant with a titanium screw. The foods tested were chewing gum and peanuts. The mean maximum load on the implant in each chewing cycle was significantly higher during peanut chewing than during gum chewing. The direction of maximum load was significantly more widely dispersed during peanut chewing than during gum chewing. The range of changes in load direction during the force-increasing phase of each chewing cycle was significantly wider during peanut chewing than during gum chewing. The load on the implant was affected by food texture in both subjects. This measurement method can be useful to investigate the mechanisms of load modulation on implants during mastication.

  19. Diamondlike carbon coating as a galvanic corrosion barrier between dental implant abutments and nickel-chromium superstructures.

    Science.gov (United States)

    Ozkomur, Ahmet; Erbil, Mehmet; Akova, Tolga

    2013-01-01

    The objectives of this study were to evaluate the galvanic corrosion behavior between titanium and nickel-chromium (Ni-Cr) alloy, to investigate the effect of diamondlike carbon (DLC) coating over titanium on galvanic corrosion behavior between titanium and Ni-Cr alloy, and to evaluate the effect of DLC coating over titanium abutments on the fit and integrity of prosthetic assemblies by scanning electron microcopy (SEM). Five Ni-Cr and 10 titanium disks with a diameter of 5 mm and thickness of 3 mm were prepared. DLC coating was applied to five titanium disks. Electrode samples were prepared, and open circuit potential measurements, galvanic current measurements over platinum electrodes, and potentiodynamic polarization tests were carried out. For the SEM evaluation, 20 Ni-Cr alloy and 10 gold alloy superstructures were cast and prepared over 30 abutments. DLC coating was applied to 10 of the abutments. Following the fixation of prosthetic assemblies, the samples were embedded in acrylic resin and cross sectioned longitudinally. Internal fit evaluations were carried out through examination of the SEM images. Titanium showed more noble and electrochemically stable properties than Ni-Cr alloy. DLC coating over the cathode electrode served as an insulating film layer over the surface and prevented galvanic coupling. Results of the SEM evaluations indicated that the DLC-coated and titanium abutments showed no statistically significant difference in fit. Hence, no adverse effects on the adaptation of prosthetic components were found with the application of DLC coating over abutment surfaces. DLC coating might serve as a galvanic corrosion barrier between titanium abutments and Ni-Cr superstructures.

  20. No influence of simultaneous bone-substitute application on the success of immediately loaded dental implants: a retrospective cohort study.

    Science.gov (United States)

    Kopp, Sigmar; Behrend, Detlef; Kundt, Günther; Ottl, Peter; Frerich, Bernhard; Warkentin, Mareike

    2013-06-01

    To examine the influence of bone-substitute application during implantation on the success of immediately placed and loaded dental implants. A total of 147 consecutive patients (age, 16.5-80.4 years) were provided with 696 immediately loaded implants. The mean follow-up time was 34.1 months. Of these implants, 50.4% (n=351) were immediately placed into extraction sockets. A total of 119 implants were added by simultaneous bone-substitute application (NanoBone, Artoss GmbH, Rostock Germany), whereas the other implants were placed in healed bone. Univariate and multivariate analysis was performed using IBM SPSS V.20. The overall implant success rate was 96.1%. Implants with simultaneous bone replacement had a hazard ratio of 0.877 (p=0.837); 95% CI, 0.253-3.04). Factors found to be statistically significant modifiers of success on multivariate analysis (p<0.05) included type of superstructure (p<0.001), implant-abutment connection (p<0.001), membrane use (p=0.010), and jaw (p=0.026). None of the other factors investigated were significant modifiers. The present study demonstrates high success rates for immediately loaded implants and their superstructures independent of the simultaneous application of bone substitute. The declared aim of socket preservation, the prevention avoiding bone loss, is achieved in the immediate implant placement scenario under immediate-loading conditions.

  1. Comparison of three-implant-supported fixed dentures and two-implant-retained overdentures in the edentulous mandible: a pilot study of treatment efficacy and patient satisfaction.

    Science.gov (United States)

    De Kok, Ingeborg J; Chang, Kuang-Han; Lu, Tsui-Shan; Cooper, Lyndon F

    2011-01-01

    The mandibular two-implant overdenture has been shown to be a highly successful treatment. However, overdenture patients who desire a fixed prosthesis may not be satisfied with a removable overdenture. This prospective study sought to compare prosthetic outcomes, patient satisfaction, and survival rates of implants between two-implant-supported overdentures (IODs) and three-implant-supported fixed dentures (ISFDs). Twenty completely edentulous patients were randomly and equally assigned to two groups. New conventional complete dentures were made, and the mandibular denture was used as a surgical guide during implant placement. Implants were placed in one stage, followed by a mandibular denture soft reline (provisional loading). Ball attachments were inserted at 8 weeks, and ISFDs were delivered at 16 weeks. IODs were connected to the attachments at 8 weeks, using each patients's existing denture. The definitive ISFDs were fabricated using computer-aided design/computer-assisted manufacture milled titanium frameworks and acrylic resin base and teeth. Patient satisfaction and panoramic radiographs were investigated at 6 and 12 months. Both treatments had significant and positive effects on patient satisfaction and quality of life. None of the 50 implants placed had failed at 12 months of follow-up; therefore, the implant survival rate was 100%. Prosthetic complications were generally rare and easily manageable. Both the treatment modalities-the ISFD supported by three implants and the IOD supported by two implants-significantly and similarly improved patient satisfaction and oral health-related quality of life, and prosthetic complications were relatively rare for both treatments. Three implants can be used to support a mandibular fixed prosthesis; however, a longer observation period is needed to validate this treatment modality.

  2. Economic Evaluation of Implant-Supported Overdentures in Edentulous Patients: A Systematic Review.

    Science.gov (United States)

    Zhang, Qi; Jin, Xin; Yu, Mengliu; Ou, Guoming; Matsui, Hiroyuki; Liang, Xing; Sasaki, Keiichi

    Edentulous patients benefit significantly from implant-supported overdenture prostheses. The purpose of this systematic review was to evaluate the cost-effectiveness of implant-supported overdentures (IODs) for edentulous patients. The search was limited to studies written in English and included an electronic and manual search through MEDLINE (Ovid, 1946 to November 2015), Embase (Ovid, 1966 to November 2015), Cochrane Central Register of Controlled Trials (CENTRAL) (to November 2015), and PubMed (to November 2015). Two investigators extracted the data and assessed the studies independently. No meta-analysis was conducted due to the high heterogeneity within the literature. Of the initial 583 selected articles, 10 studies involving 802 participants were included. Of these, 6 studies had a high risk of bias and the rest had an unclear risk of bias. Implant-supported prostheses were more cost-effective when compared to conventional dentures and fixed implant-supported prostheses. Overdentures supported by two implants and magnet attachment were reported as cost-effective. Implant-supported overdentures are a cost-effective treatment for edentulous patients. More clinical studies with appropriate scientific vigor are required to further assess the cost-effectiveness of implant-supported overdentures.

  3. Analysis of connection element classes and locations and of some structural requirements for the mounting of different superstructure types on transport vehicles

    Directory of Open Access Journals (Sweden)

    Zoran Đ. Majkić

    2011-04-01

    Full Text Available The paper presents the basic requirements for transport vehicles. A special request regarding the adaptation of transport vehicles for the transport of various types of cargo was taken into consideration. Superstructures and the situation arising after mounting superstructures on wheeled transport vehicles were analyzed and the following was described: console coupling, stirrups, simplex elastic coupling, two-way elastic and rigid connection elements. Vehicle torsional elasticity is provided by a proper choice of the type of connection between the superstructure and the vehicle chassis. Applying the instructions of vehicle manufacturers for using appropriate connections between the truck superstructure and the vehicle chassis provides positive torsional elasticity of the vehicle. The paper gives the general recommendations of the Volvo, Mercedes and Renault transport vehicle producers for the use of particular connection types of locations as well as structural requirements for the mounting of concrete mixers, tippers and truck tanks on their vehicles. Introduction Achieving a high level of transport effectiveness depends on a number of factors. One of the most important ones is the possibility to increase the payload share in the gross vehicle weight. This share depends on the net vehicle weight, a method of coupling the truck superstructure with the chassis frame as well as on the truck superstructure construction. Realization of this requirement is of significant importance, particularly for large business systems since it results in the reduction of number of necessary vehicles, more economic fleet maintenance and the fleet capacity increase. It is also relatively easy to adapt the vehicle for the transportation of other loads, depending on user's current needs. The adaptation is correctly performed if manufacturer's recommendations are followed during the mounting of the superstructure on the chassis. This paper gives the analysis of the

  4. Impact of implant-supported prostheses on nutritional status and oral health perception in edentulous patients.

    Science.gov (United States)

    El Osta, Nada; El Osta, Lana; Moukaddem, Farah; Papazian, Tatiana; Saad, Robert; Hennequin, Martine; Rabbaa Khabbaz, Lydia

    2017-04-01

    Improvement of nutritional status and perception of oral health are supposed to be different with complete conventional denture or implant-supported fixed or removable prostheses. Since no study has been conducted in Lebanon, the aim of our study was to assess the nutritional status and oral heath related quality of life (OHRQoL) in totally edentulous patients after treatment with complete denture or implant supported-prostheses. This was an observational clinical prospective study. A convenient sample of Lebanese people aged 60 years or more was selected between September 2013 and July 2015 from the Departments of removable and fixed prosthesis at Saint-Joseph University of Beirut. The treatment options included complete denture, implant-supported complete denture and implant-supported fixed prostheses. Nutritional status and OHRQoL were assessed with the Mini-Nutritional Assessment Index (MNA) and the Geriatric Oral Health Assessment Index (GOHAI) respectively at Baseline (first visit before treatment), 2-3 weeks after treatment (t1), 3 months (t2) and 6 months (t3) after treatment. Fifty-one participants (mean age: 69.39 ± 7.164 years) were included. The results have shown an improvement over time in nutritional status and OHRQoL for all treatment groups. However, 2-3 weeks after treatment the number of participants at risk of malnutrition was higher with complete removable denture, intermediate with implant-supported complete denture and lower with implant-supported fixed prostheses (p-value = 0.049). Moreover, the mean GOHAI score was significantly lower over time with complete removable denture compared to implant-supported prostheses (p-value nutritional status for implant supported-prostheses compared to conventional removable dentures. Therefore, it is fundamental that dentists communicate with their patients about implant treatment to understand their expectations, to explain the outcomes and achieve the desired clinical result. Copyright © 2017

  5. [Fracture of implant abutment screws and removal of a remaining screw piece

    NARCIS (Netherlands)

    Broeke, S.M. van den; Baat, C. de

    2008-01-01

    Fracture of the implant abutment screws is a complication which can render an implant useless. The prevalence of abutment screw fracture does not exceed 2.5% after 10 years. Causes are loosening of implant abutment screw, too few, too short or too narrow implants, implants not inserted perpendicular

  6. Antibacterial iodine-supported titanium implants.

    Science.gov (United States)

    Shirai, T; Shimizu, T; Ohtani, K; Zen, Y; Takaya, M; Tsuchiya, H

    2011-04-01

    Deep infection remains a serious complication in orthopedic implant surgery. In order to reduce the incidence of implant-associated infections, several biomaterial surface treatments have been proposed. This study focused on evaluating the antibacterial activity of iodine-supported titanium (Ti-I(2)) and its impact on post-implant infection, as well as determining the potential suitability of Ti-I(2) as a biomaterial. External fixation pins were used in this experiment as trial implants because of the ease of making the septic models. The antibacterial activity of the metal was measured using a modification of the Japanese Industrial Standards method. Activity was evaluated by exposing the implants to Staphylococcus aureus or Escherichia coli and comparing reaction of pathogens to Ti-I(2) vs. stainless steel and titanium controls. Ti-I(2) clearly inhibited bacterial colonization more than the control metals. In addition, cytocompatibility was assessed by counting the number of colonies that formed on the metals. The three metals showed the same amount of fibroblast colony formation. Japanese white rabbits were used as an in vivo model. Three pins were inserted into both femora of six rabbits for histological analysis. Pin sites were inspected and graded for infection and inflammation. Fewer signs of infection and inflammatory changes were observed in conjunction with the Ti-I(2) pins. Furthermore, osteoconductivity of the implant was evaluated with osteoid formation surface of the pin. Consecutive bone formation was observed around the Ti-I(2) and titanium pins, while little osteoid formation was found around the stainless steel pins. These findings suggest that Ti-I(2) has antimicrobial activity and exhibits cytocompatibility. Therefore, Ti-I(2) substantially reduces the incidence of implant infection and shows particular promise as a biomaterial. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  7. A new classification of peri-implant bone morphology: a radiographic study of patients with lower implant-supported mandibular overdentures

    NARCIS (Netherlands)

    Zhang, L.; Geraets, W.; Zhou, Y.; Wu, W.; Wismeijer, D.

    2014-01-01

    Objective This study aimed to classify peri-implant bone defects (PIBDs) on the basis of their radiographic appearance in a cohort of patients with lower implant-supported overdentures. Materials and methods Eighty-three patients with lower implant-supported overdentures were recruited to

  8. Fabrication of a Customized Ball Abutment to Correct a Nonparallel Implant Abutment for a Mandibular Implant-Supported Removable Partial Prosthesis: A Case Report

    OpenAIRE

    Hossein Dasht; Mohammadreza Nakhaei; Nafiseh teimouri

    2017-01-01

    Introduction: While using an implant-supported removable partial prosthesis, the implant abutments should be parallel to one another along the path of insertion. If the implants and their attachments are placed vertically on a similar occlusal plane, not only is the retention improved, the prosthesis will also be maintained for a longer period. Case Report: A 65-year-old male patient referred to the School of Dentistry in Mashhad, Iran with complaints of discomfort with the removable partial ...

  9. Effect of modeling of super-structure on the behaviour of reactor building raft

    International Nuclear Information System (INIS)

    Mondal, A.; Singh, A.K.; Roy, Raghupati; Verma, U.S.P.; Warudkar, A.S.

    2003-01-01

    The behaviour of the reactor building raft was studied when the stiffness of the super-structural elements is included in the analysis as compared to the results of conventional analysis ignoring the stiffness of the super-structural elements. The effect of the stiffness of the super-structures on the loss of contact of the raft under seismic environment was also investigated. In order to study the effect of horizontal springs on the behaviour of the raft particularly near the stressing gallery under seismic environment, a separate study has been carried out considering a 3D model consisting of solid elements supported on both horizontal and vertical springs. The model was analysed for all the forces applied at the top of the raft and the analysis results were compared with those of shell model. The following conclusions are drawn: (i) Idealisation of the reactor building raft using shell elements is adequate for estimating the design forces/moments on the raft. The design forces/moments obtained from FE model consisting of solid elements closely matches with those obtained from FE model with shell elements. Idealisation of the RB raft using shell elements will also reduce the problem size and the related computational efforts. (ii) The stiffness of the super-structure has significant effect on the behaviour of the raft. Consideration of the stiffness of the super structure reduces the design forces/moments significantly and hence, modelling of the stiffness of the super structure is necessary for economical design. (iii) Modelling of horizontal stiffness of the raft in terms of horizontal springs at the interface of the raft and the rock does not have significant effect on the behaviour of the raft and as such, is not required to be considered in the FE model. However, it is necessary to ensure adequate factor of safety against the overall stability of the raft

  10. Implant-supported mandibular removable partial dentures : Functional, clinical and radiographical parameters in relation to implant position

    NARCIS (Netherlands)

    Jensen, Charlotte; Speksnijder, Caroline M.; Raghoebar, Gerry M.; Kerdijk, Wouter; Meijer, Henny J A; Cune, Marco S.

    Background: Patients with a Kennedy class I situation often encounter problems with their removable partial denture (RPD). Purpose: To assess the functional benefits of implant support to RPDs, the clinical performance of the implants and teeth and to determine the most favorable implant position:

  11. Implant-supported titanium prostheses following augmentation procedures: a clinical report.

    Science.gov (United States)

    Knabe, C; Hoffmeister, B

    2003-03-01

    This report describes a novel technique for fabricating retrievable implant-supported titanium (Ti) prostheses in patients requiring a comprehensive treatment plan involving the combined efforts of maxillofacial surgery and implant prosthodontics. Following bone graft reconstructive surgery and implant placement prosthetic treatment was initiated by inserting ITI-Octa abutments. An impression was made, and a framework was fabricated by fusing Ti-cast frameworks to prefabricated titanium copings by laser-welding. This was followed by veneering or fabrication of a removable denture with Ti metal re-enforcement. Favourable clinical results have been achieved using these screw-retained Ti implant-supported restorations for patients treated with reconstructive bone graft-surgery, with clinical observation periods ranging from three to four years. The present observations suggest that these screw-retained implant-supported Ti prostheses may be a meaningful contribution to implant prosthodontics, facilitating retrievable restorations of optimum biocompatibility, good marginal precision and with a good esthetic result. However, controlled clinical studies are needed to establish the long-term serviceability of these Ti restorations.

  12. Bilateral implant-retained auricular prosthesis for a patient with congenitally missing ears. A clinical report.

    Science.gov (United States)

    Kumar, Preeti Satheesh; Satheesh Kumar, K S; Savadi, Ravindra C

    2012-06-01

    Microtia is a major congenital anomaly of the external ear. It includes a spectrum of deformities from a grossly normal but small ear to the absence of the entire external ear. These deformities account for three in every 10,000 births, with bilaterally missing ears seen in fewer than 10% of all cases. Congenital abnormalities of the ear are unlikely to result in the complete absence of the ears, but the patient presented in this article had bilateral congenitally missing ears. There was loss of anatomic landmarks and alteration of normal bony architecture. Minimal tissue was available for retention; therefore, conventional techniques could not be used for achieving retention. A two-implant-supported auricular prosthesis was planned, but the patient was found to have deficient bone in the implant site. Hence the implants were placed posterior to these sites, and the superstructure was modified to accommodate for this change in position of the implant to ensure the esthetic positioning of the prosthesis. © 2012 by the American College of Prosthodontists.

  13. The effect of implant-supported removable partial dentures on oral health quality of life.

    Science.gov (United States)

    Gates, W Day; Cooper, Lyndon F; Sanders, Anne E; Reside, Glenn J; De Kok, Ingeborg J

    2014-02-01

    Removable partial dentures (RPDs) represent standard treatment for partial edentulism despite major shortcomings. To alleviate these shortcomings, endosseous implants provide support and stability as well as contribute to maintenance of alveolar bone. This prospective, within subject, time series study evaluated patient-based outcomes of RPDs compared to implant-supported removable partial dentures (ISRPDs). The study hypothesis was that the ISRPD would substantially improve oral health quality of life for patients. Seventeen patients requesting new mandibular Kennedy I or II RPDs received one 6-mm dental implant in one or both of the posterior edentulous areas. After healing, conventional RPDs were fabricated and delivered. Twelve weeks later, second-stage surgery was performed, and ball abutments with Clix attachments were inserted, thereby converting the prostheses to ISRPDs. Oral health quality of life was evaluated using the 49-item Oral Health Impact Profile (OHIP-49) questionnaire. The OHIP-49 was administered prior to treatment (baseline), at 6 and 12 weeks following RPD delivery and at 6 and 12 weeks following ISRPD conversion. Radiographic evaluation was performed at 6 and 12 weeks following ISRPD conversion. In statistical analysis, a fixed-slope random intercept variance components model took account of the multiple observations per person over time. In 17 subjects, 29 of 30 implants survived. The failed implant was replaced without complications. Abutment complications were limited to one abutment loosening and one attachment replacement. Minor prosthodontic complications were recorded. The OHIP-49 score reduced by 11.8 points, on average, at 12 weeks following ISRPD conversion (P = 0.011). Patients reported improved oral health following conversion to an ISRPD from RPD. The ISRPD involving short implants is one treatment option that should be considered when treatment planning Kennedy Class I and II patients. © 2012 John Wiley & Sons A/S.

  14. Superstructure for high current applications in superconducting linear accelerators

    Science.gov (United States)

    Sekutowicz, Jacek [Elbchaussee, DE; Kneisel, Peter [Williamsburg, VA

    2008-03-18

    A superstructure for accelerating charged particles at relativistic speeds. The superstructure consists of two weakly coupled multi-cell subunits equipped with HOM couplers. A beam pipe connects the subunits and an HOM damper is included at the entrance and the exit of each of the subunits. A coupling device feeds rf power into the subunits. The subunits are constructed of niobium and maintained at cryogenic temperatures. The length of the beam pipe between the subunits is selected to provide synchronism between particles and rf fields in both subunits.

  15. Three-Year Outcome of Fixed Partial Rehabilitations Supported by Implants Inserted with Flap or Flapless Surgical Techniques.

    Science.gov (United States)

    Maló, Paulo; de Araújo Nobre, Miguel; Lopes, Armando

    2016-07-01

    The aim of this prospective clinical study was to evaluate the 3-year outcome of fixed partial prostheses supported by implants with immediate provisionalization without occlusal contacts inserted in predominantly soft bone with flap and flapless protocols. Forty-one patients partially rehabilitated with 72 NobelSpeedy implants (51 maxillary; 21 mandibular) were consecutively included and treated with a flapless surgical protocol (n = 20 patients; 32 implants) and flapped surgical protocol (n = 21 patients; 40 implants). Primary outcome measure was implant survival; secondary outcome measures were marginal bone resorption (comparing the bone levels at 1 and 3 years with baseline) and the incidence of biological, mechanical, and esthetic complications. Survival was computed through life tables; descriptive statistics were applied to the remaining variables of interest. Eight patients with eight implants dropped out of the study. One implant failed in one patient (flapless group) giving an overall cumulative survival rate (CSR) of 98.6%. No failures were noted with the flapped protocol (CSR 100%), while for the implants placed with the flapless surgical technique, a 96.9% CSR was registered. The overall average marginal bone resorption at 3 years was 1.37 mm (SD = 0.94 mm), with 1.14 mm (SD = 0.49 mm) and 1.60 mm (SD = 1.22 mm) for the flap and flapless groups, respectively. Mechanical complications occurred in nine patients (n = 5 patients in the flapless group; n = 4 patients in the flap group). Implant infection was registered in three implants and three patients (flapless group), who exhibited inadequate oral hygiene levels. Partial edentulism rehabilitation through immediate provisionalization fixed prosthesis supported by dental implants inserted through flap or flapless surgical techniques in areas of predominantly soft bone was viable at 3 years of follow-up. The limitations and risks of the "free-hand" method in flapless surgery should be considered when

  16. Randomized controlled clinical trial comparing two dental implants with different neck configurations.

    Science.gov (United States)

    Sanz-Martín, Ignacio; Sanz-Sánchez, Ignacio; Noguerol, Fernando; Cok, Susy; Ortiz-Vigón, Alberto; Sanz, Mariano

    2017-06-01

    Peri-implant bone levels can vary according to the implant neck macro-design and the implant-abutment interface. To compare the changes in soft and hard tissues when using a one-piece implant with a machined collar (TG) versus a two-piece implant with a progressive platform widening and a platform switching connection (SP). Partially edentulous patients willing to receive one or two implants in the posterior maxilla or mandible were randomized to the control (TG) or to the test group (SP). Final prostheses were delivered after 12 months. Radiographic measurements of interproximal bone levels (primary outcome) were assessed at implant loading and 1-year postloading. Clinical, patient related outcomes and adverse events were assessed at loading and after 6 and 12 months. Sixty-one implants were placed in 47 patients, 37 patients (18 in the TG group and 19 in the SP group), and 47 implants (23 TG and 24 SP) completed the 24-months follow up. At the patient level, a significantly greater bone resorption from baseline to implant loading was observed in the SP group (-0.42 ± 0.45 vs -0.07 ± 0.45; P = .001*), while from loading to the final visit, the TG group had significantly greater bone loss than the SP group (-0.26 ± 0.22 vs -0.11 ± 0.2; P = .020*). At 24 months after surgery, there were no significant differences between both groups (control: 0.33 ± 0.49 vs test: 0.53 ± 0.53; P = .230). Similarly, no significant differences were observed for the secondary outcomes. Both types of implant reported high survival rates and similar bone level changes, clinical parameters, and patient related outcomes after 12 months of loading. © 2017 Wiley Periodicals, Inc.

  17. Telescopic crowns as attachments for implant supported restorations: a case series.

    Science.gov (United States)

    Hoffmann, Oliver; Beaumont, Christian; Tatakis, Dimitris N; Zafiropoulos, Gregory-George

    2006-01-01

    The use of dental implants to support mandibular or maxillary overdentures is a widely used treatment modality. Advantages are an increase in retention, an increase in chewing ability, and easy access for oral hygiene procedures. While telescopic and conical crowns have been used for decades to connect natural teeth to overdentures, not many cases have been reported in the literature of telescopic crowns placed on implants to support overdentures. This article describes 7 patients with overdentures supported by telescopic crowns who received 65 implants (ITI Straumann). The cases presented in this report have been in function for up to 4.5 years. During that time no adverse events were reported. The use of telescopic crowns as attachments for implant-supported overdentures may be a viable treatment option.

  18. Pigment dispersion and chronic intraocular pressure elevation after sulcus placement of 3-piece acrylic intraocular lens.

    Science.gov (United States)

    Almond, M Camille; Wu, Michael C; Chen, Philip P

    2009-12-01

    A 55-year-old man had phacoemulsification and implantation of a 3-piece acrylic intraocular lens (IOL) (AcrySof MA60AC) in the right eye. One month postoperatively, the intraocular pressure (IOP) was 48 mm Hg and peripheral transillumination defects were noted in the iris circumferentially, with the IOL optic edge visible as a silhouette. Gonioscopy showed dense pigmentation of the trabecular meshwork in the right eye, but in the left eye, only mild trabecular meshwork pigment was seen, along with a concave peripheral iris insertion. At 21 months, the right eye required 3 medications for IOP control. While pigment dispersion has been widely reported after placement of 1-piece acrylic IOLs in the ciliary sulcus, we conclude that in susceptible individuals with a concave peripheral iris insertion, pigment dispersion can occur with sulcus placement of a 3-piece acrylic model despite its thinner optic and angulated haptics.

  19. Using individual two-posterior short implants with two-anterior standard implants in mandibular implant-supported-overdenture to enhance the patient satisfaction: A clinical report

    Directory of Open Access Journals (Sweden)

    Mehran Bahrami

    2017-01-01

    Full Text Available Introduction: Many clinical cases and the literature review have revealed implant-supported-overdentures’ (ISOs treatment success and predictability in elderly patients. According to the previous studies, all the mandibular ISOs used 2–4 implants anterior to mental foramen to retain the denture. Case Report: In this clinical report, two individual anterior standard implants and two individual posterior short implants were used to support the mandibular ISO, as well as to prevent further posterior bone resorption. This treatment option permits the patient to insert more implants in the future, and could be upgraded to implant-supported-fixed prosthesis. Discussion: The patient was completely satisfied about the final result, especially for upgrading the mastication efficiency. The patient was followed-up for more than 2 years without complication. The panoramic X-ray showed the preserved bone in the posterior region. This technique could be considered to be innovative, and more clinical cases are required to be documented as a predictable modality.

  20. Implant support for removable partial overdentures: a case report.

    Science.gov (United States)

    Halterman, S M; Rivers, J A; Keith, J D; Nelson, D R

    1999-01-01

    Functional stability and the preservation of remaining alveolar bone are primary, and often elusive, goals when restoring the partially edentulous arch. The incorporation of dental implants for the partial support of removable prostheses offers a practical adjunct in the fulfillment of these objectives. Planning for complex courses of treatment that include dental implants requires close coordination between the surgeon and the restorative dentist. Decisions that deal with type, location, size, number of implant fixtures, and design of the prosthesis are critical. All of these areas must be discussed and established as acceptable to the patient and each clinician before the initiation of treatment. In this report, we present a course of patient treatment in which a removable partial denture is supported by natural remaining teeth in conjunction with osseointegrated implants.

  1. Magnet-retained implant-supported overdentures: review and 1-year clinical report.

    Science.gov (United States)

    Ceruti, Paola; Bryant, S Ross; Lee, Jun-Ho; MacEntee, Michael I

    2010-01-01

    Open-field aluminum-nickle-cobalt magnets have been used in prosthodontics for many years, but success has been limited because these magnets are susceptible to corrosion by the saliva and because their retentive force is weak relative to the initial retention offered by mechanical attachments. More recently, magnets have been made from alloys of the rare earth elements samarium and neodymium, which provide stronger magnetic force per unit size. In addition, a new generation of laser-welded containers has improved protection from salivary corrosion. The current resurgence of interest in this type of attachment appears justified because, unlike mechanical attachments, magnets have potential for unlimited durability and might therefore be superior to mechanical ball or bar attachments for the retention of removable prostheses on implants. To date, no long-term prospective trials have been conducted to confirm the clinical durability of this new generation of magnets for retaining dentures on either teeth or implants. The aim of this study was to document initial clinical experiences and levels of satisfaction among edentulous patients treated with mandibular implant-supported overdentures retained using a new generation of rare-earth magnetic attachments. At the outset, all but one of the 17 patients had had several years of experience with implant-supported overdentures. During the first year, the mean overall satisfaction among these 17 patients increased from less than 70 to over 90 out of 100 (standardized visual analogue scale). No unusual difficulties were encountered in rendering the treatment or maintaining the attachments. This report offers preliminary evidence of the excellent potential of these magnets for retaining mandibular implant-supported overdentures.

  2. The impact on bone tissues of immediate implant-supported mandibular overdentures with cusped and cuspless teeth

    OpenAIRE

    Khalid A. Arafa

    2016-01-01

    Objectives: To examine the effects on bone tissues of immediate implant-supported mandibular overdentures with cusped or cuspless teeth. Methods: A randomized controlled trial was conducted at the Dental Clinic, Faculty of Dentistry, Al-Azhar University, Assiut Branch, Egypt, over a 12-month period from September 2013 to September 2014. Twenty patients were treated with immediate implant-supported overdentures: one group received overdentures with cusped teeth, and the other group receive...

  3. Removable Partial Denture Supported by Implants with Prefabricated Telescopic Abutments - A Case Report

    Science.gov (United States)

    Sehgal, Komal

    2014-01-01

    Implants have been designed to rehabilitate edentulous patients with fixed prosthesis or implant supported overdentures. Implant-supported single crowns and fixed partial dentures have become successful treatment alternatives to removable and fixed partial dentures. However, it is common to have clinical situations which make it impossible to use conventional as well as implant supported fixed partial dentures. The implant supported removable partial dentures can be a treatment modality that offers the multitude of benefits of implant-based therapy—biologic, biomechanical, social, and psychological to such patients. The aim of this article is to present a case report describing the fabrication and advantages of removable partial denture supported by teeth and implants for a patient with long edentulous span. The patient was satisfied with his dentures in terms of function and aesthetics. Regular follow-up visits over a period of three years revealed that the periodontal condition of remaining natural dentition and peri-implant conditions were stable. There was no evidence of excessive residual ridge resorption or mobility of the teeth, nor were any visible changes in the bone levels of the natural teeth or implants noted on radiographs. PMID:25121066

  4. Removable partial denture supported by implants with prefabricated telescopic abutments - a case report.

    Science.gov (United States)

    Kumar, Lalit; Sehgal, Komal

    2014-06-01

    Implants have been designed to rehabilitate edentulous patients with fixed prosthesis or implant supported overdentures. Implant-supported single crowns and fixed partial dentures have become successful treatment alternatives to removable and fixed partial dentures. However, it is common to have clinical situations which make it impossible to use conventional as well as implant supported fixed partial dentures. The implant supported removable partial dentures can be a treatment modality that offers the multitude of benefits of implant-based therapy-biologic, biomechanical, social, and psychological to such patients. The aim of this article is to present a case report describing the fabrication and advantages of removable partial denture supported by teeth and implants for a patient with long edentulous span. The patient was satisfied with his dentures in terms of function and aesthetics. Regular follow-up visits over a period of three years revealed that the periodontal condition of remaining natural dentition and peri-implant conditions were stable. There was no evidence of excessive residual ridge resorption or mobility of the teeth, nor were any visible changes in the bone levels of the natural teeth or implants noted on radiographs.

  5. Various Techniques to Increase Keratinized Tissue for Implant Supported Overdentures: Retrospective Case Series

    Directory of Open Access Journals (Sweden)

    Ahmed Elkhaweldi

    2015-01-01

    Full Text Available Purpose. The purpose of this retrospective case series is to describe and compare different surgical techniques that can be utilized to augment the keratinized soft tissue around implant-supported overdentures. Materials and Methods. The data set was extracted as deidentified information from the routine treatment of patients at the Ashman Department of Periodontology and Implant Dentistry at New York University College of Dentistry. Eight edentulous patients were selected to be included in this study. Patients were treated for lack of keratinized tissue prior to implant placement, during the second stage surgery, and after delivery of the final prosthesis. Results. All 8 patients in this study were wearing a complete maxillary and/or mandibular denture for at least a year before the time of the surgery. One of the following surgical techniques was utilized to increase the amount of keratinized tissue: apically positioned flap (APF, pedicle graft (PG, connective tissue graft (CTG, or free gingival graft (FGG. Conclusions. The amount of keratinized tissue should be taken into consideration when planning for implant-supported overdentures. The apical repositioning flap is an effective approach to increase the width of keratinized tissue prior to the implant placement.

  6. Influence of Palatal Coverage and Implant Distribution on Implant Strain in Maxillary Implant Overdentures.

    Science.gov (United States)

    Takahashi, Toshihito; Gonda, Tomoya; Mizuno, Yoko; Fujinami, Yozo; Maeda, Yoshinobu

    2016-01-01

    Maxillary implant overdentures are often used in clinical practice. However, there is no agreement or established guidelines regarding prosthetic design or optimal implant placement configuration. The purpose of this study was to examine the influence of palatal coverage and implant number and distribution in relation to impact strain under maxillary implant overdentures. A maxillary edentulous model with implants and experimental overdentures with and without palatal coverage was fabricated. Four strain gauges were attached to each implant, and they were positioned in the anterior, premolar, and molar areas. A vertical occlusal load of 98 N was applied through a mandibular complete denture, and the implant strains were compared using one-way analysis of variance (P = .05). The palatolabial strain was much higher on anterior implants than on other implants in both denture types. Although there was no significant difference between the strain under dentures with and without palatal coverage, palateless dentures tended to result in higher implant strain than dentures with palatal coverage. Dentures supported by only two implants registered higher strain than those supported by four or six implants. Implants under palateless dentures registered higher strain than those under dentures with palatal coverage. Anterior implants exhibited higher palatolabial strain than other implants regardless of palatal coverage and implant configuration; it is therefore recommended that maxillary implant overdentures should be supported by six implants with support extending to the distal end of the arch.

  7. The Effects on the Operating Condition of a Passenger Ship Retro-fitted with a Composite Superstructure

    DEFF Research Database (Denmark)

    Karatzas, Vasileios; Hjørnet, N. K.; Kristensen, Hans Otto Holmegaard

    2016-01-01

    As sustainability and climate change have come on the politi-cal agenda, the shipping industry will have to be operating energy efficient ships. An appealing step to achieve this goal is by designing superstructures made out of Fiber Reinforced Plastics (FRP) aiming at the reduction of the ship......’s lightship weight. The benefits of a light superstructure become most prominent in large passenger ships, as the superstructures constitute a significant percentage of the lightship. Additional-ly, depending on the size of the ship, the superstructure may tower several decks above the weather deck, affecting...

  8. Compliance with Supportive Periodontal Treatment in Patients with Dental Implants.

    Science.gov (United States)

    Hu, Kai-Fang; Lin, Ying-Chu; Ho, Kun-Yen; Chou, Yu-Hsiang

    The need for dental implants is increasing, and supportive periodontal treatment can achieve long-term success and prevent peri-implantitis. Contributing factors to noncompliance with long-term scheduled supportive periodontal treatment remain unclear. To investigate whether demographic and clinical characteristics are associated with noncompliance, the authors analyzed data for patients who had received dental implants. The authors recruited patients participating in a supportive periodontal treatment program after receiving permanent prostheses on implants placed from 2005 to 2013. Demographic data and dental treatment histories were collected. Compliance was defined as a record of participation in a standard supportive periodontal treatment program for at least 1 year. The chi-square test, log-rank test, Kaplan-Meier survival curve, and Cox proportional hazards model were used for statistical analysis. The study included 120 patients (259 implants, 60% compliance). The two groups (compliant and noncompliant) differed significantly in frequency distributions for sex (P = .0017), educational level (P = .0325), and histories of substance use (P = .0016), periodontitis (P = .0005), and root planing or flap surgery (P = .0002). The Kaplan-Meier survival curves and log-rank test showed that increases in cumulative continuation rates were significantly associated with male sex (P = .0025); body mass index ≥ 24 kg/m² (P = .0093); and a history of periodontitis (P implant placement, root planing or flap surgery was the crucial factor in determining compliance with supportive periodontal treatment. However, well-designed large-scale studies with a larger sample size are needed to confirm the findings of this study.

  9. Implant-abutment connections on single crowns: a systematic review.

    Science.gov (United States)

    Ceruso, F M; Barnaba, P; Mazzoleni, S; Ottria, L; Gargari, M; Zuccon, A; Bruno, G; DI Fiore, A

    2017-01-01

    Different implant-abutment connections have been developed in the effort of reducing mechanical and biological failure. The most frequent complications are screw loosening, abutment or implant fracture and marginal bone loss due to overload and bacterial micro-leakage. Ideal connection should work as a one-piece implant avoiding the formation of a micro-gap at the implant-abutment interface. Different in vitro and in vivo researches have been published to compare the implant-abutment connections actually available: external hexagon, internal hexagon and conical finding different amount of micro-gap, micro-leakage and marginal bone loss. The aim of this article is to describe, according to the most recent literature, different kind of fixture-abutment connections and their clinical and mechanical advantages or disadvantages.

  10. Bilateral Congenital Absence of the Stapes Superstructure in Two Siblings

    Directory of Open Access Journals (Sweden)

    Jose Ignacio Undabeitia

    2014-01-01

    Full Text Available Middle ear ossicle malformations are an uncommon event. Among them, the congenital absence of the stapes is a very rare condition that is seldom described in the literature. We report the cases of two women, aged 19 and 22 , who presented with a long history of conductive deafness. An exploratory tympanotomy was performed and the absence of the stapes superstructure and an abnormal position of the facial nerve could be observed. A bone anchored hearing aid (BAHA was implanted in both patients with good results. It is believed that stapes agenesis is related to an abnormal development of the facial nerve, which by the 5th to 6th week of gestation would interpose between the otic capsule and the stapes blastema, preventing these structures from contacting. A long history of nonprogressive hearing loss from birth or early childhood is the key to reach a diagnosis. Several treatment options have been described. The authors opted for a hearing aid due to the high risk of facial nerve lesion, with good functional results.

  11. Prevalence of Peri-Implant Mucositis and Peri-Implantitis in Patients Treated with a Combination of Axial and Tilted Implants Supporting a Complete Fixed Denture

    Directory of Open Access Journals (Sweden)

    Nicolò Cavalli

    2015-01-01

    Full Text Available Objectives. The aim of this retrospective study was to assess the incidence and prevalence of peri-implant mucositis and peri-implantitis in patients with a fixed full-arch prosthesis supported by two axial and two tilted implants. Materials and Methods. Sixty-nine patients were included in the study. Each patient received a fixed full-arch prosthesis supported by two mesial axial and two distal tilted implants to rehabilitate the upper arch, the lower arch, or both. Three hundred thirty-six implants for 84 restorations were delivered. Patients were scheduled for follow-up visits every 6 months in the first 2 years and yearly after. At each follow-up visit peri-implant mucositis and peri-implantitis were diagnosed if present. Results. The overall follow-up range was from 12 to 130 months (mean 63,2 months. Three patients presented peri-implantitis. The prevalence of peri-implant mucositis ranged between 0 and 7,14% of patients (5,06% of implants while the prevalence of peri-implantitis varied from 0 to 4,55% of patients (3,81% of implants. Conclusions. The prevalence and incidence of peri-implant mucositis and peri-implantitis are lower than most of the studies in literature. Therefore this kind of rehabilitation could be considered a feasible option, on the condition of adopting a systematic hygienic protocol.

  12. Effects of Repeated Screw Tightening on Implant Abutment Interfaces in Terms of Bacterial and Yeast Leakage in Vitro: One-Time Abutment Versus the Multiscrewing Technique.

    Science.gov (United States)

    Calcaterra, Roberta; Di Girolamo, Michele; Mirisola, Concetta; Baggi, Luigi

    2016-01-01

    Screw loosening can damage the interfaces of implant components, resulting in susceptibility to contamination of the internal parts by microorganisms. The aim of this study was to investigate the impact of abutment screw retightening on the leakage of two different types of bacteria, Streptococcus sanguinis and Fusobacterium nucleatum, and of the yeast Candida albicans. Two types of implant-abutment systems with tube-in-tube interfaces were tested. Groups A and B each used a different type of system that consisted of 20 different pieces that were assembled according to the manufacturer's torque recommendations; four samples in each group were closed just one time, four samples three times, four samples five times, four samples seven times, and four samples nine times. The implants of groups A and B were contaminated with 0.1 μL of microbial solution just before being assembled for the last time to minimize the possibility of contamination. Results showed a direct correlation between the number of colony-forming units grown in the plates and the closing/opening cycles of the implant-abutment systems. Within the limitations of this study, the results indicate the possibility that repeated closing/opening cycles of the implant-abutment unit may influence bacterial/yeast leakage, most likely as a consequence of decreased precision of the coupling between the abutment and the internal part of the dental implant. These findings suggest that a one-time abutment technique may avoid microbiologic leakage in cases of implant-abutment systems with tube-in-tube interfaces.

  13. Influence of implant number on the biomechanical behaviour of mandibular implant-retained/supported overdentures: a three-dimensional finite element analysis.

    Science.gov (United States)

    Liu, Jingyin; Pan, Shaoxia; Dong, Jing; Mo, Zhongjun; Fan, Yubo; Feng, Hailan

    2013-03-01

    The aim of this study was to evaluate strain distribution in peri-implant bone, stress in the abutments and denture stability of mandibular overdentures anchored by different numbers of implants under different loading conditions, through three-dimensional finite element analysis (3D FEA). Four 3D finite element models of mandibular overdentures were established, using between one and four Straumann implants with Locator attachments. Three types of load were applied to the overdenture in each model: 100N vertical and inclined loads on the left first molar and a 100N vertical load on the lower incisors. The biomechanical behaviours of peri-implant bone, implants, abutments and overdentures were recorded. Under vertical load on the lower incisors, the single-implant overdenture rotated over the implant from side to side, and no obvious increase of strain was found in peri-implant bone. Under the same loading conditions, the two-implant-retained overdenture showed more apparent rotation around the fulcrum line passing through the two implants, and the maximum equivalent stress in the abutments was higher than in the other models. In the three-implant-supported overdenture, no strain concentration was found in cortical bone around the middle implant under three loading conditions. Single-implant-retained mandibular overdentures do not show damaging strain concentration in the bone around the only implant and may be a cost-effective treatment option for edentulous patients. A third implant can be placed between the original two when patients rehabilitated by two-implant overdentures report constant and obvious denture rotation around the fulcrum line. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Implant-supported mandibular removable partial dentures; patient-based outcome measures in relation to implant position

    NARCIS (Netherlands)

    Jensen, Charlotte; Raghoebar, Gerry M.; Kerdijk, Wouter; Meijer, Henny J. A.; Cune, Marco S.

    2016-01-01

    Objectives: To assess the benefits of implant support to Removable Partial Dentures (RPD) in patients with a bilateral free-ending situation in the mandible and to determine the most favorable implant position: the premolar (PM) or the molar (M) region. Methods: Thirty subjects with a bilateral

  15. Bar versus ball attachments for implant-supported overdentures in complete edentulism: A systematic review.

    Science.gov (United States)

    Anas El-Wegoud, Marwah; Fayyad, Ahmed; Kaddah, Amal; Nabhan, Ashraf

    2018-04-01

    Implant-supported overdenture is one of the most predictable treatment options used in complete edentulism. However, differences have been reported between bar and ball attachments used to retain overdentures in terms of patient satisfaction and prosthesis retention. The purpose of this study is to compare the effectiveness of bar and ball attachments for conventionally loaded implant-supported overdentures in completely edentulous patients to improve patient satisfaction and prosthesis retention. We conducted the review according to the Cochrane methods and following MECIR standards. We searched Cochrane Oral Health Group Trial register, Cochrane Central Register of Controlled Trials, MEDLINE, and the WHO ICTRP (March 31, 2017). Two review authors assessed trials for inclusion and risk of bias, extracted data, and checked for accuracy. We have expressed results as risk ratio or mean differences, together with their 95% confidence intervals. We included 10 trials (465 participants). After 5 y, one trial reported higher patient satisfaction when bar attachment was used (MD 1.30, 95% CI 0.20-2.40), and reported no difference between both systems in prosthesis retention (MD -0.90, 95% CI -1.90 to 0.10). Two trials reported no implant failures after 1 and 5 y in both attachments. Downgrading of evidence was based on the unclear risk of bias of included studies and the wide CI crossing the line of no effect. There is insufficient evidence to support bar or ball attachment to be used with implant-supported overdentures in completely edentulous patients to improve patient satisfaction and prosthesis retention (PROSPERO 2014:CRD42014014594). © 2017 Wiley Periodicals, Inc.

  16. The effect of varying implant position in immediately loaded implant-supported mandibular overdentures.

    Science.gov (United States)

    Shaarawy, Mohammed A; Aboelross, Ehab M

    2013-06-01

    This study was carried out to evaluate the effect of varying implant position in immediately loaded implant-supported mandibular overdentures on peri-implant bone density, muscle activity, and patient satisfaction. Fourteen completely edentulous patients were selected for the study. After complete denture construction, patients were divided into 2 equal groups. Four dental implants were installed bilaterally in the interforaminal region in the first group, while in the second group, 4 dental implants were inserted bilaterally: 2 in the interforaminal region and 2 in the first molar area. Immediately after suturing, telescopic abutments were screwed to the implants, and the retaining caps were picked up into the fitting surface of the lower denture, which was delivered to the patient. Patients were recalled for radiographic bone density evaluation just after denture delivery and then at 3, 6, and 12 months thereafter. Muscle activities of masseter and temporalis muscles as well as patient satisfaction were also evaluated. The results of the study showed a high success rate approximating 98.2% of the immediately loaded implants. The electromyographic (EMG) records of both muscles in group 1 were significantly higher during chewing hard food after 3 months compared with group 2 (P overdentures through posterior placement beyond the interforaminal area results in a favorable response in terms of increased peri-implant bone density as well as decreased EMG activity of masseter and temporalis muscles.

  17. Masticatory function with implant-supported overdentures

    NARCIS (Netherlands)

    van Kampen, FMC; van der Bilt, A; Cune, MS; Fontijn-Tekamp, FA; Bosman, F

    The type of attachment that is used in implant-supported mandibular overdentures may influence the retention and stability of the prosthesis and, thus, masticatory function. In this within- subject cross- over clinical trial, we examined the hypothesis that greater retention and stability of the

  18. Two Versus Three Narrow-Diameter Implants with Locator Attachments Supporting Mandibular Overdentures: A Two-Year Prospective Study

    Directory of Open Access Journals (Sweden)

    Ali M. El-Sheikh

    2012-01-01

    Full Text Available Purpose. To compare treatment outcome (survival rate, condition of hard and soft peri-implant tissues and prosthodontic maintenance requirements of two versus three narrow-diameter bone level implants with Locator attachments supporting mandibular overdentures. Materials and Methods. Twenty completely edentulous patients with atrophic mandibles were treated. Ten patients (Group A were treated with overdentures supported by two narrow (3.3-mm diameter implants (Straumann AG, Basel, Switzerland and ten patients (Group B were treated with overdentures supported by three narrow implants. Locator (Zest Anchors, USA attachments were used for prosthetic anchorage. Standardized clinical and radiographic parameters (survival rate, plaque index, calculus index, gingival index, bleeding index, probing depth and marginal bone loss were evaluated at the time of the completion of the prosthetic treatment (baseline and after 6, 12 and 24 months of functional loading. Prosthodontic maintenance requirements were also scored. Results. Only one implant was lost (Group B during the healing period. There were no significant differences with regards to any of the studied clinical and radiographic parameters between the two groups (>0.05. Few prosthetic complications were recorded. Conclusions. No need to insert more than two narrow-diameter bone level implants with Locator attachments in cases of atrophic mandible to support an overdenture, however, long-term prospective studies are required to support this notion.

  19. Retrospective analysis of 56 edentulous dental arches restored with 344 single-stage implants using an immediate loading fixed provisional protocol: statistical predictors of implant failure.

    Science.gov (United States)

    Kinsel, Richard P; Liss, Mindy

    2007-01-01

    The purpose of this retrospective study was to evaluate the effects of implant dimensions, surface treatment, location in the dental arch, numbers of supporting implant abutments, surgical technique, and generally recognized risk factors on the survival of a series of single-stage Straumann dental implants placed into edentulous arches using an immediate loading protocol. Each patient received between 4 and 18 implants in one or both dental arches. Periapical radiographs were obtained over a 2- to 10-year follow-up period to evaluate crestal bone loss following insertion of the definitive metal-ceramic fixed prostheses. Univariate tests for failure rates as a function of age ( or = 60 years), gender, smoking, bone grafting, dental arch, surface type, anterior versus posterior, number of implants per arch, and surgical technique were made using Fisher exact tests. The Cochran-Armitage test for trend was used to evaluate the presence of a linear trend in failure rates regarding implant length and implant diameter. Logistic regression modeling was used to determine which, if any, of the aforementioned factors would predict patient and implant failure. A significance criterion of P = .05 was utilized. Data were collected for 344 single-stage implants placed into 56 edentulous arches (39 maxillae and 17 mandibles) of 43 patients and immediately loaded with a 1-piece provisional fixed prosthesis. A total of 16 implants failed to successfully integrate, for a survival rate of 95.3%. Increased rates of failure were associated with reduced implant length, placement in the posterior region of the jaw, increased implant diameter, and surface treatment. Implant length emerged as the sole significant predictor of implant failure. In this retrospective analysis of 56 consecutively treated edentulous arches with multiple single-stage dental implants loaded immediately, reduced implant length was the sole significant predictor of failure.

  20. Effect of implant number and distribution on load transfer in implant-supported partial fixed dental prostheses for the anterior maxilla: A photoelastic stress analysis study.

    Science.gov (United States)

    Lee, Jae-In; Lee, Yoon; Kim, Yu-Lee; Cho, Hye-Won

    2016-02-01

    The 4-, 3- or even 2-implant-supported partial fixed dental prosthesis (PFDP) designs have been used to rehabilitate the anterior edentulous maxilla. The purpose of this in vitro study was to compare the stress distribution in the supporting tissues surrounding implants placed in the anterior maxilla with 5 PFDP designs. A photoelastic model of the human maxilla with an anterior edentulous region was made with photoelastic resin (PL-2; Vishay Micro-Measurements), and 6 straight implants (OsseoSpeed; Astra Tech AB) were placed in the 6 anterior tooth positions. The 5 design concepts based on implant location were as follows: model 6I: 6 implants; model 2C2CI: 4 implants (2 canines and 2 central incisors); model 2C2LI: 4 implants (2 canines and 2 lateral incisors); model 2C1CI: 3 implants (2 canines and 1 central incisor); and model 2C: 2 canines. A load of 127.4 N was applied on the cingulum of 3 teeth at a 30-degree angle to the long axis of the implant. Stresses that developed in the supporting structure were recorded photographically. The 6-implant-supported PFDP exhibited the most even and lowest distribution of stresses in all loading conditions. When the canine was loaded, the 2- or 3-implant-supported PFDP showed higher stresses around the implant at the canine position than did the 4- or 6-implant-supported PFDP. When the central incisor or lateral incisor was loaded, the two 4-implant-supported PFDPs exhibited similar levels of stresses around the implants and showed lower stresses than did the 2- or 3-implant-supported PFDP. Implant number and distribution influenced stress distribution around the implants in the anterior maxilla. With a decrease in implant number, the stresses around the implants increased. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  1. Retention system for implant-supported dentures used by brazilian dentists who work in implant dentistry

    OpenAIRE

    Saturnino Aparecido Ramalho; Fábio Pontes Dantas

    2010-01-01

    Objective: To provide the dentists with support in the choice of the cement or screw type of retention for implant-supported dentures, according to the patient’s problem. Methods: An opinion questionnaire was applied to a sample of 468 participants, all dentists working in the field of Implant Dentistry, of whom 272 (58.1%) participated in the 4th International Congress of Osseointegration of APCD, held in São Paulo (SP) from 6 to 9 May 2004, 119 (25.4%) participated in the 2nd International ...

  2. Comparison of patient's satisfaction with implant-supported mandibular overdentures and complete dentures

    Directory of Open Access Journals (Sweden)

    Yu-Hwa Pan

    2014-06-01

    Full Text Available Background: The purpose of this study was to compare patients' subjective experiences with respect to long-term satisfaction with mandibular implant-retained overdentures versus conventional complete dentures. Methods: Among 85 completely edentulous patients, 60 were treated with four one-stage titanium implants and overdentures retained by a cast bar with extracoronal attachments. These patients constituted the experimental group, and were subsequently evaluated clinically over a period of up to 6 years. The other 25 patients constituted the control group and were treated with conventional complete dentures without implant retained. All the patients (n = 60 in the experimental group responded to questions on their experiences before and after treatment with the implant-retained overdentures. Sixty percent (n = 15 of the 25 patients in the control group responded to the questionnaire. Results: No implants or restorations failed during the observation period. The experimental group, however, showed significant differences with the control group in terms of their responses to the questionnaire. Conclusion: The use of implants to retain and support the overdenture improved comfort and gave the experimental patients greater self-confidence in social interactions, in addition to more effective oral rehabilitation. The results demonstrate that the effects of rehabilitation of the mandibular arch with an implant-retained overdenture are predictable.

  3. The impact on bone tissues of immediate implant-supported mandibular overdentures with cusped and cuspless teeth

    Directory of Open Access Journals (Sweden)

    Khalid A. Arafa

    2016-01-01

    Full Text Available Objectives: To examine the effects on bone tissues of immediate implant-supported mandibular overdentures with cusped or cuspless teeth. Methods: A randomized controlled trial was conducted at the Dental Clinic, Faculty of Dentistry, Al-Azhar University, Assiut Branch, Egypt, over a 12-month period from September 2013 to September 2014. Twenty patients were treated with immediate implant-supported overdentures: one group received overdentures with cusped teeth, and the other group received overdentures with cuspless teeth. The rate of implant success was assessed clinically and radiographically at 3, 6, 9, and 12 months. The data were collected by a questionnaire, an observation checklist, and radiography. The data were then analyzed using computerized methods. Results: Overdentures with cusped teeth showed a significant improvement in the clinical criteria, including the absence of clinical implant mobility, pain, and bone resorption, while the clinical criteria for the absence of peri-implant radiolucency were insignificantly different between the 2 groups (p>0.05. There were no significant differences in the clinical evaluations for bone levels at the time of insertion or 3 months after insertions, while significant differences were found at 6, 9, and 12 months after insertion. Conclusion: Overdentures with cusped teeth supported by immediate implants were found superior regarding many clinical criteria than those cuspless counterparts.

  4. The impact on bone tissues of immediate implant-supported mandibular overdentures with cusped and cuspless teeth.

    Science.gov (United States)

    Arafa, Khalid A

    2016-01-01

    To examine the effects on bone tissues of immediate implant-supported mandibular overdentures with cusped or cuspless teeth. A randomized controlled trial was conducted at the Dental Clinic, Faculty of Dentistry, Al-Azhar University, Assiut Branch, Egypt, over a 12-month period from September 2013 to September 2014. Twenty patients were treated with immediate implant-supported overdentures: one group received overdentures with cusped teeth, and the other group received overdentures with cuspless teeth. The rate of implant success was assessed clinically and radiographically at 3, 6, 9, and 12 months. The data were collected by a questionnaire, an observation checklist, and radiography. The data were then analyzed using computerized methods.  Overdentures with cusped teeth showed a significant improvement in the clinical criteria, including the absence of clinical implant mobility, pain, and bone resorption, while the clinical criteria for the absence of peri-implant radiolucency were insignificantly different between the 2 groups (p more than 0.05). There were no significant differences in the clinical evaluations for bone levels at the time of insertion or 3 months after insertions, while significant differences were found at 6, 9, and 12 months after insertion. Overdentures with cusped teeth supported by immediate implants were found superior regarding many clinical criteria than those cuspless counterparts.

  5. Clinical research in implant dentistry: evaluation of implant-supported restorations, aesthetic and patient-reported outcomes.

    Science.gov (United States)

    Lang, Niklaus P; Zitzmann, Nicola U

    2012-02-01

    The articles discussed in working group 3 dealt with specific aspects of clinical research. In this context, the literature reporting on survival and complication rates of implant-supported or implant-tooth supported restorations in longitudinal studies of at least 5 years were discussed. The second aspect dealt with the evaluation of aesthetic outcomes in clinical studies and the related index systems available. Finally, the third aspect discussed dealt with patient-reported outcome measures (PROMs). A detailed appraisal of the available methodology was presented. © 2012 John Wiley & Sons A/S.

  6. Implant and root supported overdentures - a literature review and some data on bone loss in edentulous jaws.

    Science.gov (United States)

    Carlsson, Gunnar E

    2014-08-01

    To present a literature review on implant overdentures after a brief survey of bone loss after extraction of all teeth. Papers on alveolar bone loss and implant overdentures have been studied for a narrative review. Bone loss of the alveolar process after tooth extraction occurs with great individual variation, impossible to predict at the time of extraction. The simplest way to prevent bone loss is to avoid extraction of all teeth. To keep a few teeth and use them or their roots for a tooth or root-supported overdenture substantially reduces bone loss. Jaws with implant-supported prostheses show less bone loss than jaws with conventional dentures. Mandibular 2-implant overdentures provide patients with better outcomes than do conventional dentures, regarding satisfaction, chewing ability and oral-health-related quality of life. There is no strong evidence for the superiority of one overdenture retention-system over the others regarding patient satisfaction, survival, peri-implant bone loss and relevant clinical factors. Mandibular single midline implant overdentures have shown promising results but long-term results are not yet available. For a maxillary overdenture 4 to 6 implants splinted with a bar provide high survival both for implants and overdenture. In edentulous mandibles, 2-implant overdentures provide excellent long-term success and survival, including patient satisfaction and improved oral functions. To further reduce the costs a single midline implant overdenture can be a promising option. In the maxilla, overdentures supported on 4 to 6 implants splinted with a bar have demonstrated good functional results.

  7. Implant and root supported overdentures - a literature review and some data on bone loss in edentulous jaws

    Science.gov (United States)

    2014-01-01

    PURPOSE To present a literature review on implant overdentures after a brief survey of bone loss after extraction of all teeth. MATERIALS AND METHODS Papers on alveolar bone loss and implant overdentures have been studied for a narrative review. RESULTS Bone loss of the alveolar process after tooth extraction occurs with great individual variation, impossible to predict at the time of extraction. The simplest way to prevent bone loss is to avoid extraction of all teeth. To keep a few teeth and use them or their roots for a tooth or root-supported overdenture substantially reduces bone loss. Jaws with implant-supported prostheses show less bone loss than jaws with conventional dentures. Mandibular 2-implant overdentures provide patients with better outcomes than do conventional dentures, regarding satisfaction, chewing ability and oral-health-related quality of life. There is no strong evidence for the superiority of one overdenture retention-system over the others regarding patient satisfaction, survival, peri-implant bone loss and relevant clinical factors. Mandibular single midline implant overdentures have shown promising results but long-term results are not yet available. For a maxillary overdenture 4 to 6 implants splinted with a bar provide high survival both for implants and overdenture. CONCLUSION In edentulous mandibles, 2-implant overdentures provide excellent long-term success and survival, including patient satisfaction and improved oral functions. To further reduce the costs a single midline implant overdenture can be a promising option. In the maxilla, overdentures supported on 4 to 6 implants splinted with a bar have demonstrated good functional results. PMID:25177466

  8. High-resolution electron microscopy on incommensurate long-period superstructures of hexagonal-close-packed Cu-Sb alloy

    International Nuclear Information System (INIS)

    Onozuka, T.; Kakehashi, S.; Takahashi, T.; Hirabayashi, M.

    1989-01-01

    Hexagonal incommensurate long-period superstructures of the Cu-Sb alloys containing 18-20 at.% Sb have been investigated by means of superstructure imaging using a high-resolution electron microscope. Honeycomb-type distributions of hexagonal domains consisting of the commensurate superstructure of type 7a 0 -2H are observed. The incommensurabilities of superstructure can be interpreted well with a hexagonal model composed of the 7a 0 -2H domains surrounded by domain walls which contain higher Sb content than the domain interior. The observed image contrast is reproduced well with multislice computer simulations based on the structure models proposed for the 7a 0 -2H domain and the domain wall. (orig.)

  9. High-resolution electron microscopy on incommensurate long-period superstructures of hexagonal-close-packed Cu-Sb alloy

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, T.; Kakehashi, S.; Takahashi, T.; Hirabayashi, M. (Tohoku Univ., Sendai (Japan). Inst. for Materials Research)

    1989-06-01

    Hexagonal incommensurate long-period superstructures of the Cu-Sb alloys containing 18-20 at.% Sb have been investigated by means of superstructure imaging using a high-resolution electron microscope. Honeycomb-type distributions of hexagonal domains consisting of the commensurate superstructure of type 7a{sub 0}-2H are observed. The incommensurabilities of superstructure can be interpreted well with a hexagonal model composed of the 7a{sub 0}-2H domains surrounded by domain walls which contain higher Sb content than the domain interior. The observed image contrast is reproduced well with multislice computer simulations based on the structure models proposed for the 7a{sub 0}-2H domain and the domain wall. (orig.).

  10. In situ microradioscopy and microtomography of fatigue-loaded dental two-piece implants.

    Science.gov (United States)

    Wiest, Wolfram; Zabler, Simon; Rack, Alexander; Fella, Christian; Balles, Andreas; Nelson, Katja; Schmelzeisen, Rainer; Hanke, Randolf

    2015-11-01

    Synchrotron real-time radioscopy and in situ microtomography are the only techniques providing direct visible information on a micrometre scale of local deformation in the implant-abutment connection (IAC) during and after cyclic loading. The microgap formation at the IAC has been subject to a number of studies as it has been proposed to be associated with long-term implant success. The next step in this scientific development is to focus on the in situ fatigue procedure of two-component dental implants. Therefore, an apparatus has been developed which is optimized for the in situ fatigue analysis of dental implants. This report demonstrates both the capability of in situ radioscopy and microtomography at the ID19 beamline for the study of cyclic deformation in dental implants. The first results show that it is possible to visualize fatigue loading of dental implants in real-time radioscopy in addition to the in situ fatigue tomography. For the latter, in situ microtomography is applied during the cyclic loading cycles in order to visualize the opening of the IAC microgap. These results concur with previous ex situ studies on similar systems. The setup allows for easily increasing the bending force, to simulate different chewing situations, and is, therefore, a versatile tool for examining the fatigue processes of dental implants and possibly other specimens.

  11. SELF-ORGANIZATION OF LEAD SULFIDE QUANTUM DOTS INTO SUPERSTRUCTURES

    Directory of Open Access Journals (Sweden)

    Elena V. Ushakova

    2014-11-01

    Full Text Available The method of X-ray structural analysis (X-ray scattering at small angles is used to show that the structures obtained by self-organization on a substrate of lead sulfide (PbS quantum dots are ordered arrays. Self-organization of quantum dots occurs at slow evaporation of solvent from a cuvette. The cuvette is a thin layer of mica with teflon ring on it. The positions of peaks in SAXS pattern are used to calculate crystal lattice of obtained ordered structures. Such structures have a primitive orthorhombic crystal lattice. Calculated lattice parameters are: a = 21,1 (nm; b = 36,2 (nm; c = 62,5 (nm. Dimensions of structures are tens of micrometers. The spectral properties of PbS QDs superstructures and kinetic parameters of their luminescence are investigated. Absorption band of superstructures is broadened as compared to the absorption band of the quantum dots in solution; the luminescence band is slightly shifted to the red region of the spectrum, while its bandwidth is not changed much. Luminescence lifetime of obtained structures has been significantly decreased in comparison with the isolated quantum dots in solution, but remained the same for the lead sulfide quantum dots close-packed ensembles. Such superstructures can be used to produce solar cells with improved characteristics.

  12. One-stage explant-implant procedure of exposed porous orbital implants

    DEFF Research Database (Denmark)

    Toft, Peter B; Rasmussen, Marie L Roed; Prause, Jan Ulrik

    2011-01-01

    Purpose:  To investigate the risks of implant exposure after a combined explant-implant procedure in patients with an exposed porous orbital implant. Methods:  Twenty-four consecutive patients who had a combined explant-implant procedure of an exposed hydroxyapatite (21) or porous polyethylene (3...... at the same procedure in sockets without profound signs of infection. The procedure carries a possible risk of poor motility....

  13. Reverse engineering of mandible and prosthetic framework: Effect of titanium implants in conjunction with titanium milled full arch bridge prostheses on the biomechanics of the mandible.

    Science.gov (United States)

    De Santis, Roberto; Gloria, Antonio; Russo, Teresa; D'Amora, Ugo; Varriale, Angelo; Veltri, Mario; Balleri, Piero; Mollica, Francesco; Riccitiello, Francesco; Ambrosio, Luigi

    2014-12-18

    This study aimed at investigating the effects of titanium implants and different configurations of full-arch prostheses on the biomechanics of edentulous mandibles. Reverse engineered, composite, anisotropic, edentulous mandibles made of a poly(methylmethacrylate) core and a glass fibre reinforced outer shell were rapid prototyped and instrumented with strain gauges. Brånemark implants RP platforms in conjunction with titanium Procera one-piece or two-piece bridges were used to simulate oral rehabilitations. A lateral load through the gonion regions was used to test the biomechanical effects of the rehabilitations. In addition, strains due to misfit of the one-piece titanium bridge were compared to those produced by one-piece cast gold bridges. Milled titanium bridges had a better fit than cast gold bridges. The stress distribution in mandibular bone rehabilitated with a one-piece bridge was more perturbed than that observed with a two-piece bridge. In particular the former induced a stress concentration and stress shielding in the molar and symphysis regions, while for the latter design these stresses were strongly reduced. In conclusion, prosthetic frameworks changed the biomechanics of the mandible as a result of both their design and manufacturing technology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Prosthetic Consideration in Implant-supported Prosthesis: A Review of Literature.

    Science.gov (United States)

    Gowd, Manga Snigdha; Shankar, Thatapudi; Ranjan, Rajeev; Singh, Arpita

    2017-06-01

    Modern dentistry has changed tremendously with implant therapy. For the successful implant therapy, making a proper treatment plan considering both surgical and prosthetic part in mind is the key of success. Often practitioners tend to create a treatment plan overlooking the basic principles of prosthetic part. This present review has discussed various prosthetic consideration of implant-supported prosthesis. A step-by-step detailed prosthetic option with their indications has been discussed to help all dental implant practitioners in making of an optimal treatment plan for each case.

  15. Morphology-controlled hydrothermal synthesis of MnCO3 hierarchical superstructures with Schiff base as stabilizer

    International Nuclear Information System (INIS)

    Hu, He; Xu, Jie-yan; Yang, Hong; Liang, Jie; Yang, Shiping; Wu, Huixia

    2011-01-01

    Graphical abstract: MnCO3 microcrystals with hierarchical superstructures were synthesized by using the CO2 in atmosphere as carbonate ions source and Schiff base as shape guiding-agent in water/ethanol system under hydrothermal condition. Highlights: → The most interesting in this work is the use of the greenhouse gases CO 2 in atmosphere as carbonate ions source to precipitate with Mn 2+ for producing MnCO 3 crystals. → This work is the first report related to the small organic molecule Schiff base as shape guiding-agent to produce different MnCO 3 hierarchical superstructures. → We are controllable synthesis of the MnCO 3 hierarchical superstructures such as chrysanthemum, straw-bundle, dumbbell and sphere-like microcrystals. → The as-prepared MnCO 3 could be used precursor to fabricate the Mn 2 O 3 hierarchical superstructures after thermal decomposition at high temperature. -- Abstract: MnCO 3 with hierarchical superstructures such as chrysanthemum, straw-bundle, dumbbell and sphere-like were synthesized in water/ethanol system under environment-friendly hydrothermal condition. In the synthesis process, the CO 2 in atmosphere was used as the source of carbonate ions and Schiff base was used as shape guiding-agent. The different superstructures of MnCO 3 could be obtained by controlling the hydrothermal temperature, the molar ratio of manganous ions to the Schiff base, or the volume ratio of water to ethanol. A tentative growth mechanism for the generation of MnCO 3 superstructures was proposed based on the rod-dumbbell-sphere model. Furthermore, the MnCO 3 as precursor could be further successfully transferred to Mn 2 O 3 microstructure after heating in the atmosphere at 500 o C, and the morphology of the Mn 2 O 3 was directly determined by that of the MnCO 3 precursor.

  16. Zirconia Dental Implants: Investigation of Clinical Parameters, Patient Satisfaction, and Microbial Contamination.

    Science.gov (United States)

    Holländer, Jens; Lorenz, Jonas; Stübinger, Stefan; Hölscher, Werner; Heidemann, Detlef; Ghanaati, Shahram; Sader, Robert

    2016-01-01

    In recent years, dental implants made from zirconia have been further developed and are considered a reliable treatment method for replacing missing teeth. The aim of this study was to analyze dental implants made from zirconia regarding their clinical performance compared with natural teeth (control). One hundred six zirconia implants in 38 adults were analyzed in a clinical study after 1 year of loading. The plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD), probing attachment level (PAL), and creeping or recession (CR/REC) of the gingiva were detected and compared with natural control teeth (CT). Furthermore, the papilla index (PAP), Periotest values (PTV), microbial colonization of the implant/dental sulcus fluid, and patient satisfaction were assessed. The survival rate was 100%. No statistical significance was observed between implants and teeth regarding BOP, PPD, and PAL. A statistical significance was detected regarding PI and CR/REC with significantly less plaque accumulation and recession in the study group. Mean PAP was 1.76 ± 0.55, whereas the mean PTV was -1.31 ± 2.24 (range from -5 to +6). A non-statistically significant higher colonization of periodontitis/peri-implantitis bacteria was observed in the implant group. The questionnaire showed that the majority of the patients were satisfied with the overall treatment. One-piece zirconia dental implants exhibited similar clinical results (BOP, PPD, and PAL) compared with natural teeth in regard to adhesion of plaque (PI) and creeping attachment (CR/REC); zirconia implants performed even better. The favorable results for PAL and CR/REC reflect the comparable low affinity of zirconia for plaque adhesion. Patient satisfaction indicated a high level of acceptance for zirconia implants. However, a long-term follow-up is needed to support these findings.

  17. Zygoma Implant-Supported Prosthetic Rehabilitation of a Patient After Bilateral Maxillectomy.

    Science.gov (United States)

    Celakil, Tamer; Ayvalioglu, Demet Cagil; Sancakli, Erkan; Atalay, Belir; Doganay, Ozge; Kayhan, Kivanc Bektas

    2015-10-01

    Maxillectomy defects may vary from localized to extensive soft and hard tissue loss. In addition to physical and psychologic damages, functional and aesthetic aspects must be restored. This clinical report describes the rehabilitation of a patient with a zygoma implant-supported obturator prosthesis caused by a subtotal bilateral maxillectomy due to a squamous oral cell carcinoma. Prosthetic rehabilitation of this patient was performed after zygoma implant surgery. A maxillary obturator prosthesis supported by 2 osseointegrated zygoma implants was fabricated. Despite limited mouth opening and anatomic deficiencies, the patient's aesthetic and functional demands were fulfilled.

  18. Two-Implant-Supported Mandibular Overdentures: Do Clinical Denture Quality and Inter-Implant Distance Affect Patient Satisfaction?

    Science.gov (United States)

    Alfadda, Sara A; Al Amri, Mohammad D; Al-Ohali, Amal; Al-Hakami, Arwa; Al-Madhi, Noura

    To investigate the following three null hypotheses in patients rehabilitated with a mandibular overdenture supported by two unsplinted implants: (1) patient satisfaction is not related to the clinical quality of the dentures; (2) inter-implant distance (IID) has no effect on the clinical quality of the dentures; and (3) IID does not influence patient satisfaction. Forty edentulous patients who were rehabilitated with a two-implant-supported mandibular overdenture participated in the study. Independent investigators evaluated the dentures on the basis of five clinical criteria using the validated Denture Quality Evaluation Form, and the patients completed the validated Denture Satisfaction Scale. Irreversible hydrocolloid impressions of the mandible were made and poured immediately in die stone. The IID was measured by adapting an orthodontic wire to the mandibular alveolar ridge crest, extending from the center of one implant to the center of the other. Spearman correlation analyses were used to identify possible correlations, with a significance level set at P overdenture and of the maxillary conventional complete denture was significantly related to satisfaction (r = 0.389 and r = 0.44, respectively). Significant associations were found between the mandibular stability items and satisfaction with both maxillary and mandibular dentures. The stability of the maxillary denture was significantly associated with patient satisfaction with mandibular denture retention, stability, and comfort. None of the 12 denture satisfaction items were significantly associated with IID. Similarly, IID did not have an effect on the quality of either denture in terms of retention, stability, or occlusion. Denture stability was the feature that had the most influence on patient satisfaction with the mandibular overdenture and with the maxillary conventional denture. IID had no effect on the clinical quality of either denture and did not influence patient satisfaction.

  19. 40 CFR 745.228 - Accreditation of training programs: public and commercial buildings, bridges and superstructures...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Accreditation of training programs: public and commercial buildings, bridges and superstructures. [Reserved] 745.228 Section 745.228... Accreditation of training programs: public and commercial buildings, bridges and superstructures. [Reserved] ...

  20. Maxillary sinus by-pass with tilted implants via tapered-screw bone expanders in low density bone: one year follow -up of a case series.

    Science.gov (United States)

    Andreasi Bassi, M; Andrisani, C; Lopez, M A; Gaudio, R M; Lombardo, L; Lauritano, D

    2016-01-01

    In the present paper the use of tapered-screw bone expanders (TSBEs) is proposed, in combination with the placement of tilted implants in close proximity to the anterior sinus wall, solving the problem of the reduced height of the alveolar bone in the sub-antral area. The Authors named the procedure: Tilted Implant Expansion Osteotomy (TIEO). Fifteen patients (10 females and 5 males, mean age 47.8±8.15 years) with distal edentulous maxillae were enrolled in this study. For each edentulous site 2 implants were placed, the anterior implant in the area of the most anterior missing tooth while, the posterior implant, immediately in front of the maxillary sinus, with an inclined position. Adopting the aforesaid procedure, 34 cylindrical two-piece implants were placed, 17 of which were placed in tilted position, in order to by-pass the maxillary sinus. After a healing period of 4-6 months, the second stage surgery was performed. The cases were finalized by metal-ceramic cementable restorations with a variable number of elements, from 2 to 4, without any cantilever element. The post finalization follow-up was at 12 months. Survival rate was 100% since no fixtures were lost. At the one-year follow-up the clinical and radiological appearance of the soft and hard tissues was optimal and no pathological signs were recorded. TIEO is a promising surgical procedure for oral rehabilitation of maxillary edentulous sites and represents a therapeutic alternative to sinus lift techniques.

  1. A conceptual knowledge-link model for supporting dental implant process

    OpenAIRE

    Szejka , Anderson Luis; Canciglieri , Osiris ,; Rudek , Marcelo; Panetto , Hervé

    2014-01-01

    International audience; Computer aided techniques widely used as diagnostic and surgical procedures tools are scarcely applied in implantology, which continues using visualization of CT images to define the parameters for dental implant process leaving to the dentist discretion the implant determination, since only the images analysis is non-deterministic. Thus, this research proposes the development of a knowledge-link model integrated to a reasoner system to support dental implant process t...

  2. In situ microradioscopy and microtomography of fatigue-loaded dental two-piece implants

    Energy Technology Data Exchange (ETDEWEB)

    Wiest, Wolfram; Zabler, Simon, E-mail: simon.zabler@physik.uni-wuerzburg.de [University of Würzburg (Germany); Rack, Alexander [European Synchrotron Radiation Facility (France); Fella, Christian; Balles, Andreas [University of Würzburg (Germany); Nelson, Katja; Schmelzeisen, Rainer [Medical Centre – University of Freiburg (Germany); Hanke, Randolf [University of Würzburg (Germany); Fraunhofer EZRT, Fürth (Germany)

    2015-10-09

    Results of a novel in situ microradiography and microtomography setup for the study of fatigue processes are presented. This setup is optimized for the requirements of dental implants and use at synchrotron imaging beamlines. Synchrotron real-time radioscopy and in situ microtomography are the only techniques providing direct visible information on a micrometre scale of local deformation in the implant–abutment connection (IAC) during and after cyclic loading. The microgap formation at the IAC has been subject to a number of studies as it has been proposed to be associated with long-term implant success. The next step in this scientific development is to focus on the in situ fatigue procedure of two-component dental implants. Therefore, an apparatus has been developed which is optimized for the in situ fatigue analysis of dental implants. This report demonstrates both the capability of in situ radioscopy and microtomography at the ID19 beamline for the study of cyclic deformation in dental implants. The first results show that it is possible to visualize fatigue loading of dental implants in real-time radioscopy in addition to the in situ fatigue tomography. For the latter, in situ microtomography is applied during the cyclic loading cycles in order to visualize the opening of the IAC microgap. These results concur with previous ex situ studies on similar systems. The setup allows for easily increasing the bending force, to simulate different chewing situations, and is, therefore, a versatile tool for examining the fatigue processes of dental implants and possibly other specimens.

  3. In situ microradioscopy and microtomography of fatigue-loaded dental two-piece implants

    International Nuclear Information System (INIS)

    Wiest, Wolfram; Zabler, Simon; Rack, Alexander; Fella, Christian; Balles, Andreas; Nelson, Katja; Schmelzeisen, Rainer; Hanke, Randolf

    2015-01-01

    Results of a novel in situ microradiography and microtomography setup for the study of fatigue processes are presented. This setup is optimized for the requirements of dental implants and use at synchrotron imaging beamlines. Synchrotron real-time radioscopy and in situ microtomography are the only techniques providing direct visible information on a micrometre scale of local deformation in the implant–abutment connection (IAC) during and after cyclic loading. The microgap formation at the IAC has been subject to a number of studies as it has been proposed to be associated with long-term implant success. The next step in this scientific development is to focus on the in situ fatigue procedure of two-component dental implants. Therefore, an apparatus has been developed which is optimized for the in situ fatigue analysis of dental implants. This report demonstrates both the capability of in situ radioscopy and microtomography at the ID19 beamline for the study of cyclic deformation in dental implants. The first results show that it is possible to visualize fatigue loading of dental implants in real-time radioscopy in addition to the in situ fatigue tomography. For the latter, in situ microtomography is applied during the cyclic loading cycles in order to visualize the opening of the IAC microgap. These results concur with previous ex situ studies on similar systems. The setup allows for easily increasing the bending force, to simulate different chewing situations, and is, therefore, a versatile tool for examining the fatigue processes of dental implants and possibly other specimens

  4. Antiphase boundaries, inversion, and ferroelastic domains in the striped-type superstructure of γ-brass Cu-Al alloys

    Science.gov (United States)

    Koyama, Y.; Hatano, M.; Tanimura, M.

    1996-05-01

    Features of the striped-type superstructure in γ-brass Cu-Al alloys have been investigated mainly by transmission electron microscopy in order to understand the role of a rhombohedral distortion in its stability. From dark field images taken from alloys exhibiting the superstructure, it was found that there exist two types of ferroelastic rhombohedral domains, which are in a twin relation. In other words, the superstructure is characterized by a periodic array of the ferroelastic domains as well as inversion antiphase boundaries. Because charge density waves should be responsible for the formation of the superstructure, as suggested in our previous paper [Phys. Rev. B 40, 5378 (1989)], the rhombohedral distortion must play a crucial role in their appearance. Presumably the distortion enlarges parallel portions of the Fermi surface. On the basis of the present experimental data, the interplay between the striped-type superstructure and the rhombohedral γ-brass structure is also discussed.

  5. Cross-pinning: the philosophy of retrievability applied practically to fixed, implant-supported prostheses.

    Science.gov (United States)

    Gervais, M J; Hatzipanagiotis, P; Wilson, P R

    2008-03-01

    Biologic and technical complications are widely reported in the dental literature and often compromise the functional and/or aesthetic features of fixed, implant-supported prostheses. Managing complications without damaging or destroying a restoration is an obvious advantage of implant-based dentistry where the option of prosthetic retrievability is almost always available. The technique of cross-pinning uses a transverse screw to secure a prosthesis to a milled implant abutment, allowing prosthetic retrievability irrespective of dental implant alignment. This study presents guidelines for cross-pinning implant-supported prostheses based on resistance form, screw mechanics and natural tooth contours. The technical aspects of cross-pinning are also discussed using examples from four implant systems.

  6. Zirconia dental implants: where are we now, and where are we heading?

    Science.gov (United States)

    Cionca, Norbert; Hashim, Dena; Mombelli, Andrea

    2017-02-01

    Despite decades of titanium as the gold standard in oral implantology, the search for alternatives has been growing. High esthetic standards and increasing incidence of titanium allergies, along with a rising demand for metal-free reconstructions, have led to the proposal of ceramics as potential surrogates. Following numerous experimental studies, zirconium dioxide (zirconia) has earned its place as a potential substitute for titanium in implantology. Yet, despite zirconia's excellent biocompatibility and tissue integration, low affinity to plaque and favorable biomechanical properties, early failures were significantly higher for zirconia implants than for titanium implants. Technical failure as a result of fracture of the material is also a major concern. So far, zirconia implants have been mainly manufactured as one-piece implant systems because of the material's limitations. Nevertheless, various two-piece systems have been progressively emerging with promising results. Screw-retained abutments are desirable but present a major technical challenge. Innovation and technical advances will undoubtedly lead to further improvement in the reliability and strength of zirconia implants, allowing for novel designs, connections and reconstructions. Additional clinical studies are required to identify all relevant technical and biological factors affecting implant success and patients' satisfaction. However, the evidence for a final verdict is, at present, still incomplete. © 2016 The Authors. Periodontology 2000 published by John Wiley & Sons Ltd.

  7. Axial displacement of abutments into implants and implant replicas, with the tapered cone-screw internal connection, as a function of tightening torque.

    Science.gov (United States)

    Dailey, Bruno; Jordan, Laurence; Blind, Olivier; Tavernier, Bruno

    2009-01-01

    The passive fit of a superstructure on implant abutments is essential to success. One source of error when using a tapered cone-screw internal connection may be the difference between the tightening torque level applied to the abutments by the laboratory technician compared to that applied by the treating clinician. The purpose of this study was to measure the axial displacement of tapered cone-screw abutments into implants and their replicas as a function of the tightening torque level. Twenty tapered cone-screw abutments were selected. Two groups were created: 10 abutments were secured into 10 implants, and 10 abutments were secured into 10 corresponding implant replicas. Each abutment was tightened in increasing increments of 5 Ncm, from 0 Ncm to 45 Ncm, with a torque controller. The length of each sample was measured repeatedly with an Electronic Digital Micrometer. The mean axial displacement for the implant group and the replica group was calculated. The data were analyzed by the Mann-Whitney and Spearman tests. For both groups, there was always an axial displacement of the abutment upon each incremental application of torque. The mean axial displacement values varied between 7 and 12 microm for the implant group and between 6 and 21 microm for the replica group at each 5-Ncm increment. From 0 to 45 Ncm, the total mean axial displacement values were 89 microm for the implant group and 122 microm for the replica group. There was a continuous axial displacement of the abutments into implants and implant replicas when the applied torque was raised from 0 to 45 Ncm. Torque applied above the level recommended by the manufacturer increased the difference in displacement between the two groups.

  8. Occlusal wear of provisional implant-supported restorations

    NARCIS (Netherlands)

    Santing, Hendrik J.; Kleverlaan, Cornelis J.; Werner, Arie; Feilzer, Albert J.; Raghoebar, Gerry M.; Meijer, Henny J. A.

    BACKGROUND: Implant-supported provisional restorations should be resistant to occlusal wear. PURPOSE: The purpose of this laboratory study was to evaluate three-body wear of three indirect laboratory composite resins, five chair side bis-acryl resin-based materials, and two chair side

  9. Bi-layered zirconia/fluor-apatite bridges supported by ceramic dental implants: a prospective case series after thirty months of observation.

    Science.gov (United States)

    Spies, Benedikt Christopher; Witkowski, Siegbert; Butz, Frank; Vach, Kirstin; Kohal, Ralf-Joachim

    2016-10-01

    The aim of this study was to determine the success and survival rate of all-ceramic bi-layered implant-supported three-unit fixed dental prostheses (IS-FDPs) 3 years after implant placement. Thirteen patients (seven males, six females; age: 41-78 years) received two one-piece ceramic implants (alumina-toughened zirconia) each in the region of the premolars or the first molar and were finally restored with adhesively cemented bi-layered zirconia-based IS-FDPs (3 in the maxilla, 10 in the mandible) composed of CAD/CAM-fabricated zirconia frameworks pressed-over with fluor-apatite glass-ceramic ingots. At prosthetic delivery and the follow-ups after 1, 2 and 3 years, the restorations were evaluated using modified United States Public Health Service (USPHS) criteria. Restorations with minor veneer chippings, a small-area occlusal roughness, slightly soundable restoration margins, minimal contour deficiencies and tolerable color deviations were regarded as success. In case of more distinct defects that could, however, be repaired to a clinically acceptable level, IS-FDPs were regarded as surviving. Kaplan-Meier plots were used for the success/survival analyses. To verify an impact on subjective patients' perceptions, satisfaction was evaluated by visual analog scales (VAS). All patients were seen 3 years after implant installation. No IS-FDP had to be replaced, resulting in 100% survival after a mean observation period of 29.5 months (median: 30.7). At the 3-year follow-up, 7/13 IS-FDPs showed a veneer chipping, 13/13 an occlusal roughness and 12/13 minimal deficiencies of contour/color. Since six restorations showed a major chipping and/or a major occlusal roughness, the Kaplan-Meier success rate was 53.8%. However, patients' significantly improved perceptions of function, esthetics, sense, and speech at prosthetic delivery remained stable over time. Bi-layered zirconia/fluor-apatite IS-FDPs entirely survived the observation period but showed a high frequency of

  10. Influence of connection type on the biomechanical behavior of distal extension mandibular removable partial dentures supported by implants and natural teeth.

    Science.gov (United States)

    Xiao, Wei; Li, Zhiyong; Shen, Shiqian; Chen, Shaowu; Chen, Sulin; Wang, Jiawei

    2016-02-01

    Few studies are performed to evaluate the influence of connection type on the stress distribution of distal extension mandibular removable partial dentures (RPDs) supported by both implants and natural teeth. In this study, five three-dimensional finite element models were prepared to simulate mandibular bilateral partially edentulous arches. Four were RPDs supported by both implants and natural teeth, and the other one was RPDs supported only by natural teeth. The maximum equivalent (EQV) stress values of bone around implants, the abutments, and the mucosa displacements of the related supporting structures were measured. It was found that a non-rigid telescopic coping was more favorable to protect the implant than a rigid telescopic coping. Compared with other connection types, the easy resilient attachment (ERA) system seemed to be effective to associate implant without complications. However, the results obtained in the present study should be cautiously interpreted in the clinic.

  11. Neuromuscular coordination of masticatory muscles in subjects with two types of implant-supported prostheses.

    Science.gov (United States)

    Ferrario, Virgilio F; Tartaglia, Gianluca M; Maglione, Michele; Simion, Massimo; Sforza, Chiarella

    2004-04-01

    To compare the electromyographic (EMG) characteristics of masticatory muscles in patients with fixed implant-supported prostheses and implant overdentures. Nineteen subjects aged 45-79 years were examined. Fourteen were edentulous and had been successfully rehabilitated with (a) maxillary and mandibular implant-supported fixed prostheses (seven patients); (b) mandibular implant overdentures and maxillary complete dentures (seven patients). Five control subjects had natural dentition or single/partial (no more than two teeth) tooth or implant fixed dentures. Surface EMG of the masseter and temporal muscles was performed during unilateral gum chewing and during maximum teeth clenching. To reduce biological and instrumental noise, all values were standardized as percentage of a maximum clenching on cotton rolls. During clenching, temporal muscle symmetry was larger in control subjects and fixed implant-supported prosthesis patients than in overdenture patients (analysis of variance, P=0.005). No differences were found in masseter muscle symmetry or in muscular torque. Muscle activities (integrated areas of the EMG potentials over time) were significantly larger in control subjects than in implant-supported prosthesis patients (P=0.014). In both patient groups, a poor neuromuscular coordination during chewing, with altered muscular patterns, and a smaller left-right symmetry than in control subjects were found (P=0.05). No differences in masticatory frequency were found. Surface EMG analysis of clenching and chewing showed that fixed implant-supported prostheses and implant overdentures were functionally equivalent. Neuromuscular coordination during chewing was inferior to that found in subjects with natural dentition.

  12. Cone-morse implant connection system significantly reduces bacterial leakage between implant and abutment: an in vitro study.

    Science.gov (United States)

    Baj, A; Bolzoni, A; Russillo, A; Lauritano, D; Palmieri, A; Cura, F; Silvestre, F J; Giannì, A B

    2017-01-01

    Osseointegrated implants are very popular dental treatments today in the world. In osseointegrated implants, the occlusal forces are transmitted from prosthesis through an abutment to a dental implant. The abutment is connected to the implant by mean of a screw. A screw is the most used mean for connecting an implant to an abutment. Frequently the screws break and are lost. There is an alternative to screw retained abutment systems: the cone-morse connection (CMC). The CMC, thanks to the absence of the abutment screw, guarantees no micro-gaps, no micro-movements, and a reduction of bacterial leakage between implant and abutment. As P. gingivalis and T. forsythia penetration might have clinical relevance, it was the purpose of this investigation to evaluate molecular leakage of these two bacteria in a new CMC implants systems (Leone Spa®, Florence, Italy). To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Four cone-morse Leone implants (Leone® Spa, Florence, Italy) were immerged in a bacterial culture for 24 h and bacteria amount was then measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 3% for P. gingivalis and 4% for T. forsythia. Cone-morse connection implant system has very low bacterial leakage percentage and is similar to one-piece implants.

  13. Satisfaction and complications with the Titan® one-touch release penile implant

    DEFF Research Database (Denmark)

    Lindeborg, Lisa; Fode, Mikkel; Fahrenkrug, Lasse

    2014-01-01

    OBJECTIVE: The aim of this study was to assess complication rates and patient satisfaction with Coloplast Titan® one-touch release (OTR) inflatable penile implants inserted at one university hospital centre between November 2008 and April 2011. MATERIAL AND METHODS: Overall, 33 patients with orga......OBJECTIVE: The aim of this study was to assess complication rates and patient satisfaction with Coloplast Titan® one-touch release (OTR) inflatable penile implants inserted at one university hospital centre between November 2008 and April 2011. MATERIAL AND METHODS: Overall, 33 patients...... with organic erectile dysfunction underwent penile implant surgery during the study period. The Titan OTR inflatable penile implants were inserted using a penoscrotal approach. Patient and partner satisfaction was assessed with the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) questionnaire...

  14. The role of prosthetic abutment material on the stress distribution in a maxillary single implant-supported fixed prosthesis

    Energy Technology Data Exchange (ETDEWEB)

    Peixoto, Hugo Eduardo, E-mail: hugo.e.peixoto@hotmail.com [Implantology Team, Latin American Institute of Research and Education in Dentistry, Curitiba, Paraná (Brazil); Bordin, Dimorvan, E-mail: dimorvan_bordin@hotmail.com [Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Limeira avenue, 901-Vila Rezende, Piracicaba, SP 13414-903 (Brazil); Del Bel Cury, Altair A., E-mail: altcury@fop.unicamp.br [Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Limeira avenue, 901-Vila Rezende, Piracicaba, SP 13414-903 (Brazil); Silva, Wander José da, E-mail: wanderjose@fop.unicamp.br [Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Limeira avenue, 901-Vila Rezende, Piracicaba, SP 13414-903 (Brazil); Faot, Fernanda, E-mail: fernanda.faot@gmail.com [Department of Restorative Dentistry, School of Dentistry, Federal University of Pelotas, Gonçalves Chaves, 457, 2nd floor, Pelotas, Rio Grande do Sul 96015-560 (Brazil)

    2016-08-01

    Purpose: Evaluate the influence of abutment's material and geometry on stress distribution in a single implant-supported prosthesis. Materials and Methods: Three-dimensional models were made based on tomographic slices of the upper middle incisor area, in which a morse taper implant was positioned and a titanium (Ti) or zirconia (ZrN) universal abutments was installed. The commercially available geometry of titanium (T) and zirconia (Z) abutments were used to draw two models, TM1 and ZM1 respectively, which served as control groups. These models were compared with 2 experimental groups were the mechanical properties of Z were applied to the titanium abutment (TM2) and vice versa for the zirconia abutment (ZM2). Subsequently, loading was simulated in two steps, starting with a preload phase, calculated with the respective friction coefficients of each materials, followed by a combined preload and chewing force. The maximum von Mises stress was described. Data were analyzed by two-way ANOVA that considered material composition, geometry and loading (p < 0.05). Results: Titanium and zirconia abutments showed similar von Mises stresses in the mechanical part of the four models. The area with the highest concentration of stress was the screw thread, following by the screw body. The highest stress levels occurred in screw thread was observed during the preloading phase in the ZM1 model (931 MPa); and during the combined loading in the TM1 model (965 MPa). Statistically significant differences were observed for loading, the material × loading interaction, and the loading × geometry interaction (p < 0.05). Preloading contributed for 77.89% of the stress (p < 0.05). There were no statistically significant differences to the other factors (p > 0.05). Conclusion: The screw was the piece most intensely affected, mainly through the preload force, independent of the abutment's material. - Highlights: • The abutment's screw was the most impaired piece of the

  15. Implant and prosthodontic survival rates with implant fixed complete dental prostheses in the edentulous mandible after at least 5 years: a systematic review.

    Science.gov (United States)

    Papaspyridakos, Panos; Mokti, Muizzaddin; Chen, Chun-Jung; Benic, Goran I; Gallucci, German O; Chronopoulos, Vasilios

    2014-10-01

    The treatment of mandibular edentulism with implant fixed complete dental prostheses (IFCDPs) is a routinely used treatment option. The study aims to report the implant and prosthodontic survival rates associated with IFCDPs for the edentulous mandible after an observation period of a minimum 5 years. An electronic MEDLINE/PubMED search was conducted to identify randomized controlled clinical trials and prospective studies with IFCDPs for the edentulous mandible. Clinical studies with at least 5-year follow-up were selected. Pooled data were statistically analyzed and cumulative implant- and prosthesis survival rates were calculated by meta-analysis, regression, and chi-square statistics. Implant-related and prosthesis-related factors were identified and their impact on survival rates was assessed. Seventeen prospective studies, including 501 patients and 2,827 implants, were selected for meta-analysis. The majority of the implants (88.5% of all placed implants) had been placed in the interforaminal area. Cumulative implant survival rates for rough surface ranged from 98.42% (95% confidence interval [CI]: 97.98-98.86) (5 years) to 96.86% (95% CI: 96.00-97.73) (10 years); smooth surface implant survival rates ranged from 98.93% (95% CI: 98.38-99.49) (5 years) to 97.88% (95% CI: 96.78-98.98) (10 years). The prosthodontic survival rates for 1-piece IFCDPs ranged from 98.61% (95% CI: 97.80-99.43) (5 years) to 97.25% (95% CI: 95.66-98.86) (10 years). Treatment with mandibular IFCDPs yields high implant and prosthodontic survival rates (more than 96% after 10 years). Rough surface implants exhibited cumulative survival rates similar to the smooth surface ones (p > .05) in the edentulous mandible. The number of supporting implants and the antero-posterior implant distribution had no influence (p > .05) on the implant survival rate. The prosthetic design and veneering material, the retention type, and the loading protocol (delayed, early, and immediate) had no

  16. Automatic recognition of ship types from infrared images using superstructure moment invariants

    Science.gov (United States)

    Li, Heng; Wang, Xinyu

    2007-11-01

    Automatic object recognition is an active area of interest for military and commercial applications. In this paper, a system addressing autonomous recognition of ship types in infrared images is proposed. Firstly, an approach of segmentation based on detection of salient features of the target with subsequent shadow removing is proposed, as is the base of the subsequent object recognition. Considering the differences between the shapes of various ships mainly lie in their superstructures, we then use superstructure moment functions invariant to translation, rotation and scale differences in input patterns and develop a robust algorithm of obtaining ship superstructure. Subsequently a back-propagation neural network is used as a classifier in the recognition stage and projection images of simulated three-dimensional ship models are used as the training sets. Our recognition model was implemented and experimentally validated using both simulated three-dimensional ship model images and real images derived from video of an AN/AAS-44V Forward Looking Infrared(FLIR) sensor.

  17. Role of Steric Hindrance in the Crystal Packing of Z′ = 4 Superstructure of Trimethyltin Hydroxide

    KAUST Repository

    Dey, S.; Schö nleber, A.; Mondal, S.; Ali, S. I.; van Smaalen, S.

    2018-01-01

    The roomerature crystal structure of trimethyltin hydroxide, (CH)SnOH, has been described by Anderson et al. [Cryst. Growth Des. 2011, 11, 820-826] as a 2a × 2b × 8c, 32-fold superstructure. We report a a × b × 8c, eight-fold superstructure

  18. Musings on the puzzle piece.

    Science.gov (United States)

    Goin-Kochel, Robin P

    2016-02-01

    Following is a brief musing on Roy Grinker's discussion of what the puzzle piece symbolizes for autism during his presentation at the 2015 International Meeting for Autism Research. In his words, "The puzzle piece is ubiquitous." It likely holds a different meaning for each of us, and this is how one autism researcher sees it. © The Author(s) 2015.

  19. CNC-milled titanium frameworks supported by implants in the edentulous jaw: a 10-year comparative clinical study.

    Science.gov (United States)

    Örtorp, Anders; Jemt, Torsten

    2012-03-01

    No long-term clinical studies covering more than 5 years are available on Computer Numeric Controlled (CNC) milled titanium frameworks. To evaluate and compare the clinical and radiographic performance of implant-supported prostheses provided with CNC titanium frameworks in the edentulous jaw with prostheses with cast gold-alloy frameworks during the first 10 years of function. Altogether, 126 edentulous patients were by random provided with 67 prostheses with titanium frameworks (test) in 23 maxillas and 44 mandibles, and with 62 prostheses with gold-alloy castings (control) in 31 maxillas and 31 mandibles. Clinical and radiographic 10-year data were collected for the groups and statistically compared on patient level. The 10-year prosthesis and implant cumulative survival rate was 95.6% compared with 98.3%, and 95.0% compared with 97.9% for test and control groups, respectively (p > .05). No implants were lost after 5 years of follow-up. Smokers lost more implants than nonsmokers after 5 years of follow-up (p .05), respectively. One prosthesis was lost in each group due to loss of implants, and one prosthesis failed due to framework fracture in the test group. Two metal fractures were registered in each group. More appointments of maintenance were needed for the prostheses in the maxilla compared with those in the mandible (p CNC-milled titanium frameworks are a viable alternative to gold-alloy castings for restoring patients with implant-supported prostheses in the edentulous jaw. © 2009 Wiley Periodicals, Inc.

  20. Scattering of the radiofrequency electromagnetic field by orthopedic bone support frame implants

    International Nuclear Information System (INIS)

    Mohsin, S.A.; Sheikh, N.M.

    2009-01-01

    The interaction of the fields in MRI (Magnetic Resonance Imaging) with orthopedic implants is investigated. The primary interaction is the scattering of the MRI RF (Radiofrequency) field by the implants. As a specific case study, the scattel-cd field due to a bone support frame implant is computed by the finite-element-method. The support frame has steel pins of significant length embedded in tissue. The induced surface current distributions on the steel pins and the spatial electric field distributions in the surrounding tissue have been obtained. (author)

  1. Two-stage dental implants inserted in a one-stage procedure : a prospective comparative clinical study

    NARCIS (Netherlands)

    Heijdenrijk, Kees

    2002-01-01

    The results of this study indicate that dental implants designed for a submerged implantation procedure can be used in a single-stage procedure and may be as predictable as one-stage implants. Although one-stage implant systems and two-stage.

  2. A one-dimensional collisional model for plasma-immersion ion implantation

    International Nuclear Information System (INIS)

    Vahedi, V.; Lieberman, M.A.; Alves, M.V.; Verboncoeur, J.P.; Birdsall, C.K.

    1991-01-01

    Plasma-immersion ion implantation (also known as plasma-source ion implantation) is a process in which a target is immersed in a plasma and a series of large negative-voltage pulses are applied to it to extract ions from the plasma and implant them into the target. A general one-dimensional model is developed to study this process in different coordinate systems for the case in which the pressure of the neutral gas is large enough that the ion motion in the sheath can be assumed to be highly collisional

  3. Dual jaw treatment of edentulism using implant-supported monolithic zirconia fixed prostheses.

    Science.gov (United States)

    Altarawneh, Sandra; Limmer, Bryan; Reside, Glenn J; Cooper, Lyndon

    2015-01-01

    This case report describes restoration of the edentulous maxilla and mandible with implant supported fixed prostheses using monolithic zirconia, where the incisal edges and occluding surfaces were made of monolithic zirconia. Edentulism is a debilitating condition that can be treated with either a removable or fixed dental prosthesis. The most common type of implant-supported fixed prosthesis is the metal acrylic (hybrid), with ceramo-metal prostheses being used less commonly in complete edentulism. However, both of these prostheses designs are associated with reported complications of screw loosening or fracture and chipping of acrylic resin and porcelain. Monolithic zirconia implant-supported fixed prostheses have the potential for reduction of such complications. In this case, the CAD/CAM concept was utilized in fabrication of maxillary and mandibular screw-retained implant-supported fixed prostheses using monolithic zirconia. Proper treatment planning and execution coupled with utilizing advanced technologies contributes to highly esthetic results. However, long-term studies are required to guarantee a satisfactory long-term outcome of this modality of treatment. This case report describes the clinical and technical procedures involved in fabrication of maxillary and mandibular implant-supported fixed prostheses using monolithic zirconia as a treatment of edentulism, and proposes the possible advantages associated with using monolithic zirconia in eliminating dissimilar interfaces in such prostheses that are accountable for the most commonly occurring technical complication for these prostheses being chipping and fracture of the veneering material. © 2015 Wiley Periodicals, Inc.

  4. Cost-effectiveness of implant-supported mandibular removable partial dentures.

    Science.gov (United States)

    Jensen, Charlotte; Ross, Jamila; Feenstra, Talitha L; Raghoebar, Gerry M; Speksnijder, Caroline; Meijer, Henny J A; Cune, Marco S

    2017-05-01

    The aim of this study was to conduct a cost-effectiveness analysis comparing conventional removable partial dentures (RPDs) and implant-supported RPDs (ISRPDs) treatment in patients with an edentulous maxilla and a bilateral free-ending situation in the mandible. Thirty subjects were included. A new RPD was made and implant support was provided 3 months later. Treatment costs (opportunity costs and costs based on tariffs) were calculated. Treatment effect was expressed by means of the Dutch Oral Health Impact Profile questionnaire (OHIP-NL49), a chewing ability test (Mixing Ability Index, MAI) and a short-form health survey measuring perceived general health (SF-36), which was subsequently converted into quality-adjusted-life-years (QALYs). The incremental cost-effectiveness ratio (ICER) was the primary outcome measure of cost-effectiveness, comparing both treatment strategies. The mean total opportunity costs were €981 (95% CI €971-€991) for the RPD treatment and €2.480 (95% CI €2.461-€2.500) for the ISRPD treatment. The total costs derived from the national tariff structure were €850 for the RPD treatment and €2.610 for the ISRPD treatment. The ICER for OHIP-NL49 and MAI using the opportunity costs was €80 and €786, respectively. When using the tariff structure, corresponding ICERs were €94 and €921. The effect of supporting an RPD with implants when expressed in QALYs was negligible; hence an ICER was not determined. It is concluded that depending on the choice of outcome measure and monetary threshold, supporting an RPD with implants is cost-effective when payers are willing to pay more than €80 per OHIP point gained. Per MAI point gained, an additional €786 has to be invested. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Implant-tooth-supported fixed partial prostheses: correlations between in vivo occlusal bite forces and marginal bone reactions.

    Science.gov (United States)

    Akça, Kivanç; Uysal, Serdar; Cehreli, Murat Cavit

    2006-06-01

    To evaluate maximal occlusal bite forces (MOF) and marginal bone level (MBL) changes in patients with implant-tooth-supported fixed partial prostheses (FPP). Twenty nine partially edentulous patients consecutively who received 34 three-occlusal unit FPP with terminal implant and tooth support were subjected to quantification of MOFs using a sub-miniature load cell connected to a data acquisition system and measurement of the MBL changes around implants in digitalized periapical radiographs obtained at prostheses delivery and 24-month follow-up. MOFs for implant support (mean: 353.61 N) significantly differed from tooth support (mean: 275.48 N) (P 0.05). MBL changes at mesial and distal sites of the implants at 24 months of functional loading were 0.28 and 0.097 mm respectively. Although MOFs under functional loading might indicate an increase in load participation for supporting implant, the rigid connection between implant and natural tooth via three-occlusal unit FPP does not jeopardize the time-dependent MBL stability of the implant under functional loads.

  6. Superstructure-based optimization of biorefinery networks: Production of biodiesel

    DEFF Research Database (Denmark)

    Bertran, Maria-Ona; Orsi, Albert; Gani, Rafiqul

    2015-01-01

    through a practical case study for the production biodiesel from a variety of feedstock. The different biorefinery processing alternatives are represented in a superstructure and the associated data is collected and stored in a database. Once a specific biorefinery synthesis problem is formulated...

  7. Maxillary Implant-Supported Fixed Prosthesis: A Survey of Reviews and Key Variables for Treatment Planning.

    Science.gov (United States)

    Gallucci, German O; Avrampou, Marianna; Taylor, James C; Elpers, Julie; Thalji, Ghadeer; Cooper, Lyndon F

    2016-01-01

    This review was conducted to provide information to support the establishment of clinical guidelines for the treatment of maxillary edentulism using implant-supported fixed dental prostheses. Initial efforts were directed toward a systematic review with a defined PICO question: "For maxillary edentulous patients with dental implants treated using a fixed prosthesis, what is the impact of prosthesis design on prosthesis survival and complications?" Following a title search of more than 3,000 titles identified by electronic search of PubMed, 180 articles were identified that addressed the clinical evaluation of maxillary dental implant prostheses. The broad methodologic heterogeneity and clinical variation among reports precluded this approach for a systematic review. The information was extracted using a standardized extraction table by two pairs of investigators, and the reported outcomes were then summarized according to reported outcomes for implant prostheses supported by four, six, or eight implants using unitary or segmented prostheses. This review indicated that high prosthetic survival is observed using all approaches. The advantages of using fewer implants and a unitary prosthesis are revealed in the surgical phases, and complications commonly involve the fracture or detachment of acrylic teeth and reduced access for proper oral hygiene and related biologic complications. Using six implants typically involved grafting of posterior regions with advantages of reduced cantilevers and redundancy of implant support. Reduced prosthesis survival in these cases was associated with poor implant distribution. Segmented prostheses supported by six or more implants offered greater prosthetic survival, perhaps due to posterior implant placement. Advantages of a segmented prosthesis included pragmatic issues of accommodating divergent implants, attaining passive fit, combining prosthetic materials, and relative simplicity of repair. The existing literature demonstrated

  8. Immediately loaded implants supporting fixed prostheses in the edentulous maxilla: a preliminary clinical and radiologic report.

    Science.gov (United States)

    Bergkvist, Göran; Sahlholm, Sten; Karlsson, Ulf; Nilner, Krister; Lindh, Christina

    2005-01-01

    To evaluate the survival rate of immediately loaded ITI sand-blasted, large-grit, acid-etched (SLA) solid-screw dental implants in the edentulous maxilla after 8 months of loading. Twenty-eight patients (mean age 63 years) with edentulous maxillae each received 6 implants and 1 implant-supported fixed provisional prosthesis within 24 hours after surgery. After a mean healing time of 15 weeks, the patient received a definitive, screw-retained, implant-supported fixed prosthesis. A total of 168 implants were placed. Clinical parameters were registered after 1 month of loading with the implant-supported fixed prostheses as well as 8 months after implant placement. Radiologic examinations and assessments were made at implant placement and after 8 months. The mean marginal bone level at implant placement was 1.6 mm (range 0 to 5.1; SD 1.1) apical of the reference point (the implant shoulder). The mean marginal bone level at the 8-month follow-up was 3.2 mm (range 0.4 to 5.9; SD 1.1) apical of the reference point. Three implants failed during the healing period. The improved results in the present study might be a result of the positive effect of splinting the implants immediately after placement. ITI SLA solid-screw implants immediately loaded (ie, loaded within 24 hours of placement) and supporting fixed prostheses had successful survival rates after 8 months. The present results constitute a solid baseline for future follow-up studies.

  9. Development of patient-based questionnaire about aesthetic and functional differences between overdentures implant-supported and overdentures tooth-supported. Study of 43 patients with a follow up of 1 year.

    Science.gov (United States)

    Gargari, M; Prete, V; Pujia, M; Ceruso, F M

    2012-10-01

    Development of patient-based questionnaire about aesthetic and functional differences between overdentures implant-supported and overdentures tooth-supported. Study of 43 patients with a follow up of 1 year. The aim of this study is to compare functional efficiency and patients satisfaction between tooth-supported and implant-supported overdenture through a questionnaire that accurately reflects the real concerns of patients with dental prosthesis. Forty-three patients were selected from the out patient clinic, Department of Dentistry "Fra G.B. Orsenigo Ospedale San Pietro F.B.F.", Rome, Italy. Their age were ranging from 61 to 83 years. Eighteen patients were rehabilitated with overdentures supported by natural teeth and twenty-five with overdentures implant-supported. DISCUSSION AND RESULT: The questionnaire proposed one year after the insertion of the prosthetis has showed that there isn't difference statistically significant in terms of function, phonetics and aesthetics between overdenture implant-supported and tooth-supported. The results of the questionnaire showed that the patients generally had a high level of satisfaction concern to the masticatory function, esthetics and phonetics. In addition, on average, they haven't difficulty in removal and insertion of the denture and in oral hygiene. They haven't in both groups problems related to fractures.

  10. Linking experiment and theory for three-dimensional networked binary metal nanoparticle–triblock terpolymer superstructures

    KAUST Repository

    Li, Zihui

    2014-02-21

    © 2014 Macmillan Publishers Limited. Controlling superstructure of binary nanoparticle mixtures in three dimensions from self-assembly opens enormous opportunities for the design of materials with unique properties. Here we report on how the intimate coupling of synthesis, in-depth electron tomographic characterization and theory enables exquisite control of superstructure in highly ordered porous three-dimensional continuous networks from single and binary mixtures of metal nanoparticles with a triblock terpolymer. Poly(isoprene-block-styrene-block-(N,N-dimethylamino)ethyl methacrylate) is synthesized and used as structure-directing agent for ligand-stabilized platinum and gold nanoparticles. Quantitative analysis provides insights into short-and long-range nanoparticle-nanoparticle correlations, and local and global contributions to structural chirality in the networks. Results provide synthesis criteria for next-generation mesoporous network superstructures from binary nanoparticle mixtures for potential applications in areas including catalysis.

  11. Maxillary Overdentures Supported by Four Splinted Direct Metal Laser Sintering Implants: A 3-Year Prospective Clinical Study

    Directory of Open Access Journals (Sweden)

    Francesco Mangano

    2014-01-01

    Full Text Available Purpose. Nowadays, the advancements in direct metal laser sintering (DMLS technology allow the fabrication of titanium dental implants. The aim of this study was to evaluate implant survival, complications, and peri-implant marginal bone loss of DMLS implants used to support bar-retained maxillary overdentures. Materials and Methods. Over a 2-year period, 120 implants were placed in the maxilla of 30 patients (18 males, 12 females to support bar-retained maxillary overdentures (ODs. Each OD was supported by 4 implants splinted by a rigid cobalt-chrome bar. At each annual follow-up session, clinical and radiographic parameters were assessed. The outcome measures were implant failure, biological and prosthetic complications, and peri-implant marginal bone loss (distance between the implant shoulder and the first visible bone-to-implant contact, DIB. Results. The 3-year implant survival rate was 97.4% (implant-based and 92.9% (patient-based. Three implants failed. The incidence of biological complication was 3.5% (implant-based and 7.1% (patient-based. The incidence of prosthetic complication was 17.8% (patient-based. No detrimental effects on marginal bone level were evidenced. Conclusions. The use of 4 DMLS titanium implants to support bar-retained maxillary ODs seems to represent a safe and successful procedure. Long-term clinical studies on a larger sample of patients are needed to confirm these results.

  12. Maxillary overdentures supported by four splinted direct metal laser sintering implants: a 3-year prospective clinical study.

    Science.gov (United States)

    Mangano, Francesco; Luongo, Fabrizia; Shibli, Jamil Awad; Anil, Sukumaran; Mangano, Carlo

    2014-01-01

    Purpose. Nowadays, the advancements in direct metal laser sintering (DMLS) technology allow the fabrication of titanium dental implants. The aim of this study was to evaluate implant survival, complications, and peri-implant marginal bone loss of DMLS implants used to support bar-retained maxillary overdentures. Materials and Methods. Over a 2-year period, 120 implants were placed in the maxilla of 30 patients (18 males, 12 females) to support bar-retained maxillary overdentures (ODs). Each OD was supported by 4 implants splinted by a rigid cobalt-chrome bar. At each annual follow-up session, clinical and radiographic parameters were assessed. The outcome measures were implant failure, biological and prosthetic complications, and peri-implant marginal bone loss (distance between the implant shoulder and the first visible bone-to-implant contact, DIB). Results. The 3-year implant survival rate was 97.4% (implant-based) and 92.9% (patient-based). Three implants failed. The incidence of biological complication was 3.5% (implant-based) and 7.1% (patient-based). The incidence of prosthetic complication was 17.8% (patient-based). No detrimental effects on marginal bone level were evidenced. Conclusions. The use of 4 DMLS titanium implants to support bar-retained maxillary ODs seems to represent a safe and successful procedure. Long-term clinical studies on a larger sample of patients are needed to confirm these results.

  13. Turbulent thermal superstructures in Rayleigh-Bénard convection

    Science.gov (United States)

    Stevens, Richard J. A. M.; Blass, Alexander; Zhu, Xiaojue; Verzicco, Roberto; Lohse, Detlef

    2018-04-01

    We report the observation of superstructures, i.e., very large-scale and long living coherent structures in highly turbulent Rayleigh-Bénard convection up to Rayleigh Ra=109 . We perform direct numerical simulations in horizontally periodic domains with aspect ratios up to Γ =128 . In the considered Ra number regime the thermal superstructures have a horizontal extend of six to seven times the height of the domain and their size is independent of Ra. Many laboratory experiments and numerical simulations have focused on small aspect ratio cells in order to achieve the highest possible Ra. However, here we show that for very high Ra integral quantities such as the Nusselt number and volume averaged Reynolds number only converge to the large aspect ratio limit around Γ ≈4 , while horizontally averaged statistics such as standard deviation and kurtosis converge around Γ ≈8 , the integral scale converges around Γ ≈32 , and the peak position of the temperature variance and turbulent kinetic energy spectra only converge around Γ ≈64 .

  14. Nonlinear analysis of collapse mechanism in superstructure vehicle

    Science.gov (United States)

    Nor, M. K. Mohd; Ho, C. S.; Ma'at, N.

    2017-04-01

    The EU directive 2001/85/EC is an official European text which describes the specifications for "single deck class II and III vehicles" required to be approved by the regulation UN/ECE no.66 (R66). To prevent the catastrophic consequences by occupant during an accident, the Malaysian government has reinforced the same regulation upon superstructure construction. This paper discusses collapse mechanism analysis of a superstructure vehicle using a Crash D nonlinear analysis computer program based on this regulation. The analysis starts by hand calculation to define the required energy absorption by the chosen structure. Simple calculations were then performed to define the weakest collapse mechanism after undesirable collapse modes are eliminated. There are few factors highlighted in this work to pass the regulation. Using the selected cross section, Crash D simulation showed a good result. Generally, the deformation is linearly correlates to the energy absorption for the structure with low stiffness. Failure of critical members such as vertical lower side wall must be avoided to sustain safety of the passenger compartment and prevent from severe and fatal injuries to the trapped occupant.

  15. Effect of difference in occlusal contact area of mandibular free-end edentulous area implants on periodontal mechanosensitive threshold of adjacent premolars.

    Science.gov (United States)

    Terauchi, Rie; Arai, Korenori; Tanaka, Masahiro; Kawazoe, Takayoshi; Baba, Shunsuke

    2015-01-01

    Implant treatment is believed to cause minimal invasion of remaining teeth. However, few studies have examined teeth adjacent to an implant region. Therefore, this study investigated the effect of occlusal contact size of implants on the periodontal mechanosensitive threshold of adjacent premolars. A cross-sectional study design was adopted. The Department of Oral Implantology, Osaka Dental University, was the setting where patients underwent implant treatment in the mandibular free-end edentulous area. The study population comprised of 87 patients (109 teeth) who underwent follow-up observation for at least 3 years following implant superstructure placement. As variables, age, sex, duration following superstructure placement, presence or absence of dental pulp, occlusal contact area, and periodontal mechanosensitive threshold were considered. The occlusal contact area was measured using Blue Silicone(®)and Bite Eye BE-I(®). Periodontal mechanosensitive threshold were measured using von Frey hair. As quantitative variables for periodontal mechanosensitive threshold, we divided subjects into two groups: normal (≤5 g) and high (≥5.1 g). For statistical analysis, we compared the two groups for the sensation thresholds using the Chi square test for categorical data and the Mann-Whitney U test for continuous volume data. For variables in which a significant difference was noted, we calculated the odds ratio (95 % confidence interval) and the effective dose. There were 93 teeth in the normal group and 16 teeth in the high group based on periodontal mechanosensitive threshold. Comparison of the two groups indicated no significant differences associated with age, sex, duration following superstructure placement, or presence or absence of dental pulp. A significant difference was noted with regard to occlusal contact area, with several high group subjects belonging to the small contact group (odds ratio: 4.75 [1.42-15.87]; effective dose: 0.29). The results of

  16. Underwater transporting method and device for incore structure cutting piece

    International Nuclear Information System (INIS)

    Kurosawa, Koichi; Chiba, Noboru; Chiba, Isao; Takada, Hiroshi; Furukawa, Hideyasu; Chiba, Noboru.

    1996-01-01

    Cutting pieces are handled by using a pick-up device connected with a wire ropes, a take-up drum, chains and a winch as cutting piece handling means, and moved freely on the water surface by a propulsion machine of a transporting means of the device to transfer them under water to a predetermined position. The pick-up device is lifted by taking-up the rope by the rotation of the take-up drum using chain-driving by way of the winch and the chains. The cut pieces are stored in a cask by lowering them in the cask and releasing the handling. In addition, if the weight of the cut pieces is recognized before cutting, and the load of the weight of the cut pieces is applied to the device previously, the balance of the device and the cut pieces can be kept, and cut pieces can be transported under water always stably. Further, if the cut pieces are supported upon cutting operation, the cut pieces are made stable, and cutting operation with good efficiency can be attained. (N.H.)

  17. Biting Force and Muscle Activity in Implant-Supported Single Mandibular Overdentures Opposing Fixed Maxillary Dentition.

    Science.gov (United States)

    Al-Magaleh, Wafaʼa R; Abbas, Nadia A; Amer, Ashraf A; Abdelkader, Ann A; Bahgat, Basma

    2016-04-01

    This study aimed to investigate the relation between biting force and masticatory muscle activity in patients treated by 3 modalities of single mandibular dentures. Forty implants were placed in 10 patients with completely edentulous mandibles. The study was divided into 3 treatment stages. Initially, each patient received a conventional mandibular complete denture. At the second stage, 4 mandibular implants were placed and the denture was refitted to their abutments. Third stage comprised connecting the denture to the implants through ball attachments. During each treatment stage, maximum biting force and muscle activity were measured during maximum clenching and chewing of soft and hard food. Biting force demonstrated a statistically significant increase by time for the 3 treatment stages. The highest muscle activity was recorded for the conventional denture followed by the implant-supported overdenture without attachment, whereas the lowest values were recorded for the implant-supported overdenture with attachment. Biting force was related mainly to the quality of denture support. Muscle activity was higher in patients with conventional denture than with implant-supported prostheses (with or without attachments).

  18. Elmo Bumpy Torus proof of principle, Phase II: Title 1 report. Volume IX. Support structure

    International Nuclear Information System (INIS)

    Conlee, J.L.

    1982-01-01

    The EBT-P support structure provides structural support for the 36 mirror coil magnets, magnet protection system, the toroidal vessel, and much of the device ancillary equipment. The structure is comprised of a primary support and a superstructure. The primary support is a reinforced concrete ring located directly inboard of the torus and is supported by nine columns. The toroidal vessel and the mirror coil magnets are cantilevered from the ring with the centerline of the torus located eight feet above the floor. The superstructure is an aluminum truss structure that rests on the concrete ring. The superstructure provides support for the device ancillary equipment. Engineering drawings of the support structure are given

  19. Retention system for implant-supported dentures used by brazilian dentists who work in implant dentistry

    Directory of Open Access Journals (Sweden)

    Saturnino Aparecido Ramalho

    2010-04-01

    Full Text Available Objective: To provide the dentists with support in the choice of the cement or screw type of retention for implant-supported dentures, according to the patient’s problem. Methods: An opinion questionnaire was applied to a sample of 468 participants, all dentists working in the field of Implant Dentistry, of whom 272 (58.1% participated in the 4th International Congress of Osseointegration of APCD, held in São Paulo (SP from 6 to 9 May 2004, 119 (25.4% participated in the 2nd International Congress of Implant Dentistry of Minas Gerais, between 10 and 12 June 2004 and 77 (16.5% were professors and specialization and master students from São Leopoldo Mandic. Results: The results showed that 254 participants opted for the screw-retained system while 214 opted for the cement-retained system. Conclusion: There was a preference for the use of the screw-retained system, and that both cemented and screw-retained systems have advantages and disadvantages, so that the dentist is left to decide and evaluate them in order to indicate and use them with confidence in different clinical cases.

  20. Esthetic Outcome of Implant Supported Crowns With and Without Peri-Implant Conditioning Using Provisional Fixed Prosthesis: A Randomized Controlled Clinical Trial.

    Science.gov (United States)

    Furze, David; Byrne, Ashley; Alam, Sonia; Wittneben, Julia-Gabriela

    2016-12-01

    Achieving an optimal esthetic result using dental implants is challenging. Fixed implant-supported provisional crowns are often used to customize the emergence profile and to individualize the surrounding peri-implant soft tissue. The objective of this study is to evaluate whether the use of a provisional implant-supported crown leads to an esthetic benefit on implants that are placed in the esthetic zone. The null hypothesis is that there is no-difference between the two study groups. Twenty single implants (Bone Level, Straumann AG, Basel, Switzerland) were inserted in consecutive patients. After reopening, a randomization process assigned them to either cohort group 1: a provisional phase with soft tissue conditioning using the "dynamic compression technique" or cohort group 2: without a provisional. Implants were finally restored with an all-ceramic crown. Follow-up examinations were performed at 3 and 12 months including implant success and survival, clinical, and radiographic parameters. After 1 year all implants successfully integrated, mean values of combined modPES and WES were 16.7 for group 1 and 10.5 for Group 2. This was statistically significant. Mean bone loss after 1 year was -0.09 and -0.08 for groups 1 and 2, respectively, without being statistically significant. A provisional phase with soft tissue conditioning does improve the final esthetic result. © 2016 Wiley Periodicals, Inc.

  1. Stress and strain distribution in three different mini dental implant designs using in implant retained overdenture: a finite element analysis study

    Science.gov (United States)

    AUNMEUNGTONG, W.; KHONGKHUNTHIAN, P.; RUNGSIYAKULL, P.

    2016-01-01

    SUMMARY Finite Element Analysis (FEA) has been used for prediction of stress and strain between dental implant components and bone in the implant design process. Purpose Purpose of this study was to characterize and analyze stress and strain distribution occurring in bone and implants and to compare stress and strain of three different implant designs. Materials and methods Three different mini dental implant designs were included in this study: 1. a mini dental implant with an internal implant-abutment connection (MDIi); 2. a mini dental implant with an external implant-abutment connection (MDIe); 3. a single piece mini dental implant (MDIs). All implant designs were scanned using micro-CT scans. The imaging details of the implants were used to simulate models for FEA. An artificial bone volume of 9×9 mm in size was constructed and each implant was placed separately at the center of each bone model. All bone-implant models were simulatively loaded under an axial compressive force of 100 N and a 45-degree force of 100 N loading at the top of the implants using computer software to evaluate stress and strain distribution. Results There was no difference in stress or strain between the three implant designs. The stress and strain occurring in all three mini dental implant designs were mainly localized at the cortical bone around the bone-implant interface. Oblique 45° loading caused increased deformation, magnitude and distribution of stress and strain in all implant models. Conclusions Within the limits of this study, the average stress and strain in bone and implant models with MDIi were similar to those with MDIe and MDIs. The oblique 45° load played an important role in dramatically increased average stress and strain in all bone-implant models. Clinical implications Mini dental implants with external or internal connections have similar stress distribution to single piece mini dental implants. In clinical situations, the three types of mini dental implant

  2. Stress and strain distribution in three different mini dental implant designs using in implant retained overdenture: a finite element analysis study.

    Science.gov (United States)

    Aunmeungtong, W; Khongkhunthian, P; Rungsiyakull, P

    2016-01-01

    Finite Element Analysis (FEA) has been used for prediction of stress and strain between dental implant components and bone in the implant design process. Purpose of this study was to characterize and analyze stress and strain distribution occurring in bone and implants and to compare stress and strain of three different implant designs. Three different mini dental implant designs were included in this study: 1. a mini dental implant with an internal implant-abutment connection (MDIi); 2. a mini dental implant with an external implant-abutment connection (MDIe); 3. a single piece mini dental implant (MDIs). All implant designs were scanned using micro-CT scans. The imaging details of the implants were used to simulate models for FEA. An artificial bone volume of 9×9 mm in size was constructed and each implant was placed separately at the center of each bone model. All bone-implant models were simulatively loaded under an axial compressive force of 100 N and a 45-degree force of 100 N loading at the top of the implants using computer software to evaluate stress and strain distribution. There was no difference in stress or strain between the three implant designs. The stress and strain occurring in all three mini dental implant designs were mainly localized at the cortical bone around the bone-implant interface. Oblique 45° loading caused increased deformation, magnitude and distribution of stress and strain in all implant models. Within the limits of this study, the average stress and strain in bone and implant models with MDIi were similar to those with MDIe and MDIs. The oblique 45° load played an important role in dramatically increased average stress and strain in all bone-implant models. Mini dental implants with external or internal connections have similar stress distribution to single piece mini dental implants. In clinical situations, the three types of mini dental implant should exhibit the same behavior to chewing force.

  3. Maxillary complete denture outcome with two-implant supported mandibular overdentures. A systematic review.

    Science.gov (United States)

    Rutkunas, Vygandas; Mizutani, Hiroshi; Peciuliene, Vytaute; Bendinskaite, Ruta; Linkevicius, Tomas

    2008-01-01

    Research data regarding maxillary complete denture outcome with two-implant supported mandibular overdentures are not consistent. Considering multiple publications on implant supported mandibular overdentures, it was decided to summarize currently present evidence on the maxillary complete dentures opposed by implant-supported mandibular overdentures, and analyze factors that could potentially influence the outcomes. The articles from 1985 to 2007 related to the topic were identified in the online MEDLINE/Pubmed and other databases and manually. Primary articles were scanned, and irrelevant studies were excluded from the further review process. Potentially relevant titles and abstracts were provisionally included for consideration on the basis of full text articles. Full text articles were obtained from on-line and printed sources. The data from the studies were extracted and reviewed. The study has failed to identify any prospective satisfying inclusion/exclusion criteria RCT reporting on maxillary bone resorption. The number of maxillary complete denture relining incidences per patient was constantly increasing during the 10-year period. Maxillary complete denture remake incidences comprised 16-33 % of the number of patients followed during the 10-year period. Comparing patient satisfaction with upper dentures at the baseline and after two years, no decrease in satisfaction was noticed. There is no evidence that maxillary ridge resorption is accelerated with certain types of two-implant supported mandibular overdenture attachments. Most common complication for the maxilla - prosthetic maintenance. There is a risk of decreased patient satisfaction with bar-supported mandibular overdenture. Further studies are needed to provide evidence for the maxillary complete denture outcome with two-implant supported mandibular overdentures.

  4. Case study for one-piece removal method of reactor vessel of nuclear ship 'Mutsu'

    International Nuclear Information System (INIS)

    Nagane, Satoru; Kitahara, Katsumi; Yoshikawa, Seiji; Miyasaka, Yasuhiko; Fukumura, Nobuo; Nisizawa, Ichiou

    2010-01-01

    A reactor installed at the center part of the nuclear ship 'Mutsu' has been stored safely and exhibited in a reactor room building since 1996. The reactor vessel and its internals are key components because of main radioactive wastes for the reasonable decommissioning plan in the future. This report describes the one-piece removal method as the one package of the reactor vessel with its internals intact with a shipping container or additional shields. The reactor vessel package (Max.100ton) will be classified acceptable for burial at the low level radioactive waste (LLW), which will be buried at a LLW pit facility under waste disposal regulations. And also, the package will be classified as an IP-2-equivalent package according to the requirement for Shipments and Packagings. (author)

  5. Post-operative hemimaxillectomy rehabilitation using prostheses supported by zygoma implants and remaining natural teeth

    Directory of Open Access Journals (Sweden)

    Xing Zhou Qu

    Full Text Available OBJECTIVES: This study aimed to evaluate the stability of prostheses supported by zygoma implants and remaining teeth for subjects who had undergone hemi-maxillectomy. METHODS: Ten patients were included in the study. Oral rehabilitation was performed using a temporary prosthesis that was supported by remaining teeth for the first three months. Then, a zygoma implant was placed to provide support for a final prosthesis in addition to the remaining teeth. Each prosthesis was tailor-made according to biomechanical three-dimensional finite element analysis results. The patients were assessed using the prosthesis functioning scale of the Memorial Sloan-Kettering Cancer Center. In addition, retention and bite force were recorded for both the temporary prosthesis and the final prosthesis. RESULTS: The mean bite force of the prosthetic first molar was increased to 69.2 N. The mean retentive force increased to 13.5 N after zygoma implant insertion. The bite force on the prosthetic first molar was improved to 229.3 N. CONCLUSION: Bite force increased significantly with the support of a zygoma implant. The use of zygoma implants in the restoration of maxillary defects improved functional outcome and patient satisfaction.

  6. A Sequential Approach to Implant-Supported Overdentures.

    Science.gov (United States)

    Kosinski, Timothy

    2016-03-01

    Fabrication of implant-supported maxillary or mandibular overdentures can seem to be difficult procedures. Many things could go wrong and/or unnoticed until the fabrication has been completed. Implants must be correctly surgically placed in viable bone at the proper angulation and spacing within an arch. The type of attachment must be considered and future treatment of the appliance should be simple and efficient. The appliance must function not only initially but also for many years to come. The author has found the use of the GPS attachment to be an ideal tool to achieve the goals of retention and stability. Careful planning is the most important part of this process, and understanding the benefits and risks of creating overdentures should be well understood by the dentists. By sequentially planning and treating these types of cases, the patient is able to function reasonably during the stages of implant healing. The final prosthesis is created and remaining teeth that held the transitional appliance in place are remove on the day of final seating. This is an excellent simplified retentive system option for those patients who are anxious about losing their teeth, even those teeth that are diseased and ugly.

  7. Superconducting superstructure for the TESLA collider

    Energy Technology Data Exchange (ETDEWEB)

    Sekutowicz, J.; Tang, C. [DESY, MHF-SL, Hamburg (Germany); Ferrario, M. [INFN, Laboratori Nazionali di Frascati, Rome (Italy)

    1998-04-01

    The Authors discuss the new layout of a cavity chain (superstructure) allowing, the Authors hope, significant cost reduction of the RF system of both linacs of the TESLA linear collider. The proposed scheme increases the fill factor and thus makes an effective gradient of an accelerator higher. The authors present mainly computations that have performed up to now and which encouraged to order the copper model of the scheme, still keeping in mind that experiments with a beam will be necessary to prove if the proposed solution can be used for the acceleration.

  8. Quality of Life of Patients Treated With Implant-Supported Mandibular Overdentures Evaluated With the Oral Health Impact Profile (OHIP-14: a Survey of 58 Patients

    Directory of Open Access Journals (Sweden)

    Ritva Kuoppala

    2013-06-01

    Full Text Available Objectives: The purpose of this study was to evaluate the oral health-related quality of life of patients treated with implant-supported mandibular overdentures and to compare the attachment systems used.Material and Methods: Altogether 112 patients treated with implant-supported mandibular overdentures in 1985 - 2004 were invited to the follow-up; 58 of them attended and replied to the Oral Health Impact Profile (OHIP-14 -questionnaire. There were 48 overdentures with a bar connection and 10 with a ball connection, the total number of implants installed and still in use was 197. The mean follow-up time was 13.7 years. The associations between the OHIP-14 variables and the patient’s age, gender as well as the number of implants supporting the overdenture and the type of attachment used were assessed.Results: The results showed that patients with implant-supported mandibular overdentures were satisfied with their oral health-related quality of life (OHRQoL. Older patients were more satisfied than younger ones in both genders. Neither the implant connection type nor the number of supporting implants seemed to have a significant influence on the OHRQoL.Conclusions: Especially older patients with mandibular implant-supported overdentures were satisfied with their oral health-related quality of life. Attachment type or the number of supporting implants did not have a significant influence on the oral health-related quality of life.

  9. Retropupillary iris claw intraocular lens implantation in aphakia for dislocated intraocular lens.

    Science.gov (United States)

    Faria, Mun Yueh; Ferreira, Nuno Pinto; Pinto, Joana Medeiros; Sousa, David Cordeiro; Leal, Ines; Neto, Eliana; Marques-Neves, Carlos

    2016-01-01

    Nowadays, dislocated intraocular lenses (IOLs) and inadequate capsular support are becoming a challenge for every ophthalmic surgeon. Explantation of dislocated IOL and iris claw IOL (ICIOL) are the techniques that have been used in our ophthalmic department. The aim of this study is to report our technique for retropupillar ICIOL. This study is a retrospective case series. A total of 105 eyes with dislocated IOL from the patients at the Department of Ophthalmology in Santa Maria Hospital, a tertiary reference hospital in Lisbon, Portugal, from January 2012 until January 2016, had been analyzed. Of these 105 eyes, 66 eyes had dislocated one-piece IOL and 39 eyes had dislocated three-piece IOL. The latter underwent iris suture of the same IOL and were excluded from this study. The remaining 66 eyes with dislocated one-piece IOL underwent pars plana vitrectomy, that is, explantation of dislocated IOL through corneal incision and an implantation of retropupillary ICIOL. Operative data and postoperative outcomes included best corrected visual acuity, IOL position, intraocular pressure, pigment dispersion, clinical signs of endothelial cell loss, and anterior chamber depth. The mean follow-up was 23 months (range: 6-48 months). The mean preoperative best corrected visual acuity was 1.260±0.771 logMAR, and postoperative best corrected visual acuity was 0.352±0.400 logMAR units. Mean vision gain was 0.909 logMar units. The patients had the following complications: 1) retinal detachment was found in one patient, 2) corneal edema was found in three patients, 3) high intraocular pressure was observed in twelve patients, 4) subluxation of the IOL was observed in one patient, and 5) macular edema was found in three eyes. The results demonstrate that retropupillary ICIOL is an easy and effective method for the correction of aphakia in patients not receiving capsule support. The safety of this procedure must be interpreted in the context of a surgery usually indicated in

  10. Failure analysis of fractured dental zirconia implants.

    Science.gov (United States)

    Gahlert, M; Burtscher, D; Grunert, I; Kniha, H; Steinhauser, E

    2012-03-01

    The purpose of the present study was the macroscopic and microscopic failure analysis of fractured zirconia dental implants. Thirteen fractured one-piece zirconia implants (Z-Look3) out of 170 inserted implants with an average in situ period of 36.75±5.34 months (range from 20 to 56 months, median 38 months) were prepared for macroscopic and microscopic (scanning electron microscopy [SEM]) failure analysis. These 170 implants were inserted in 79 patients. The patient histories were compared with fracture incidences to identify the reasons for the failure of the implants. Twelve of these fractured implants had a diameter of 3.25 mm and one implant had a diameter of 4 mm. All fractured implants were located in the anterior side of the maxilla and mandibula. The patient with the fracture of the 4 mm diameter implant was adversely affected by strong bruxism. By failure analysis (SEM), it could be demonstrated that in all cases, mechanical overloading caused the fracture of the implants. Inhomogeneities and internal defects of the ceramic material could be excluded, but notches and scratches due to sandblasting of the surface led to local stress concentrations that led to the mentioned mechanical overloading by bending loads. The present study identified a fracture rate of nearly 10% within a follow-up period of 36.75 months after prosthetic loading. Ninety-two per cent of the fractured implants were so-called diameter reduced implants (diameter 3.25 mm). These diameter reduced implants cannot be recommended for further clinical use. Improvement of the ceramic material and modification of the implant geometry has to be carried out to reduce the failure rate of small-sized ceramic implants. Nevertheless, due to the lack of appropriate laboratory testing, only clinical studies will demonstrate clearly whether and how far the failure rate can be reduced. © 2011 John Wiley & Sons A/S.

  11. Polygonal Area of Prosthesis Support with Straight and Tilted Dental Implants in Edentulous Maxillae.

    Science.gov (United States)

    Wentaschek, Stefan; Lehmann, Karl Martin; Scheller, Herbert; Weibrich, Gernot; Behneke, Nikolaus

    2016-01-01

    The aim of this in vitro study was to assess the increase in the polygonal area of implant-retained prosthesis supports in edentulous maxillae with the use of tilted distal implants compared with the use of straight distal implants, using a variety of implant lengths. A total of 25 DICOM datasets of atrophic edentulous maxillae were provided. Bone augmentations in the molar region had to be avoided. Two straight reference implants were virtually inserted in the anterior region. Two additional implants were placed far distally on both sides (4 groups: [1] straight, 12-mm length; [2] straight, 10 mm; [3] straight, 8 mm; [4] tilted, 12-16 mm). The resulting implant-supported polygon was measured for each of the 4 groups using three-dimensional planning software. The mean sagittal depth of the supported polygon in Group 1 was 9.9 mm (standard deviation [SD] 4.4) on the right and 10.2 mm (SD 4.4) on the left, and it was 33.7 mm (SD 5.8) in width. For Group 2, the mean sagittal depth was 11.5 mm (SD 5.0) on the right and 11.9 mm (SD 4.7) on the left, and the width was 35.2 mm (SD 5.6). The measurements for Group 3 were 13.8 mm (SD 4.9) deep on the right, 13.8 mm (SD 5.1) deep on the left, and 37.0 mm (SD 5.4) in width. For Group 4, the depth was 15.8 mm (SD 4.9) on the right and 16.4 mm (SD 5.8) on the left, and the width was 39.0 mm (SD 5.1). The area of implant-retained prosthesis support can be enlarged by the use of tilted implants (12 to 16 mm in length, 42 to 45 degrees) compared to the use of straight 8-mm implants (resulting increase: about 15%).

  12. Maxillary overdentures supported by four or six implants in the anterior region: 5-year results from a randomized controlled trial.

    Science.gov (United States)

    Slot, Wim; Raghoebar, Gerry M; Cune, Marco S; Vissink, Arjan; Meijer, Henny J A

    2016-12-01

    To compare a four- and six-implant maxillary overdenture after an observation period of 5 years. Fifty subjects with functional problems concerning their maxillary denture, who had ample bone volume in the anterior region to place four or six implants, were included and randomly assigned to either group. Implant and overdenture survival, clinical performance, marginal bone loss and patient satisfaction were assessed. Forty-six patients completed the 5-year follow-up. One implant failed in the six implants group (99.2% survival) and none in the four implants group (100% survival). No overdentures had to be replaced during the observation period and the number of complications was limited. Clinical function was good, with no difference in clinical parameters between the groups. Mean marginal bone resorption was 0.50 ± 0.37 and 0.52 ± 0.43 mm in the four and six implant group respectively. In patients with functional complaints of their maxillary denture, bar-supported overdentures on four implants in the anterior maxillary region were not inferior to overdentures supported by six implants after 5 years of function. Implant survival and patient satisfaction were high, clinical parameters favourable, bone loss and complications to the denture were minor in both groups (Clinical trial registration number: NTR2969). © 2016 The Authors. Journal of Clinical Periodontology Published by John Wiley & Sons Ltd.

  13. Effect of joining the sectioned implant-supported prosthesis on the peri-implant strain generated in simulated mandibular model.

    Science.gov (United States)

    Singh, Ipsha; Nair, K Chandrasekharan; Shetty, Jayakar

    2017-01-01

    The aim of this study is to evaluate the strain developed in simulated mandibular model before and after the joining of an implant-supported screw-retained prosthesis by different joining techniques, namely, arc welding, laser welding, and soldering. A specimen simulating a mandibular edentulous ridge was fabricated in heat-cured acrylic resin. 4-mm holes were drilled in the following tooth positions; 36, 33, 43, 46. Implant analogs were placed in the holes. University of California, Los Angeles, abutment was attached to the implant fixture. Eight strain gauges were attached to the acrylic resin model. Six similar models were made. Implant-supported screw-retained fixed prosthesis was fabricated in nickel-chromium alloy. A load of 400 N was applied on the prosthesis using universal testing machine. Resultant strain was measured in each strain gauge. All the prostheses were sectioned at the area between 36 and 33, 33 and 43, and 43 and 46 using 35 micrometer carborundum disc, and strain was measured in each strain gauge after applying a load of 400 N on the prosthesis. Specimens were joined by arc welding, soldering, and laser welding. After joining, a load of 400 N was applied on each prosthesis and the resultant strain was measured in each strain gauge. Highest mean strain values were recorded before sectioning of the prostheses (889.9 microstrains). Lowest mean strain values were recorded after sectioning the prosthesis and before reuniting it (225.0 microstrains). Sectioning and reuniting the long-span implant prosthesis was found to be a significant factor in influencing the peri-implant strain.

  14. Transition piece for joining together tubular pieces

    International Nuclear Information System (INIS)

    Holko, K.H.

    1981-01-01

    A transition piece for joining together tubular pieces formed respectively from a low alloy or carbon steel and a high temperature alloy containing at least 16% chromium includes a plurality of tubular parts welded together and formed from materials of selected composition with a maximum chromium content difference of 5% between adjacent parts when the chromium content of each part is below 10% and a maximum chromium difference of 7% between adjacent parts when the chromium content of either part is above 10%. The transition parts are also graded as to such characteristics as thermal expansion coefficient. The transition parts at opposite ends of the transition joint have chromium percentages similar to the tubular pieces to which they are to be joined. The parts may be joined by fusion and/or friction welding and parts may be formed by fusion weld deposition. (author)

  15. Intracorporeal Heat Distribution from Fully Implantable Energy Sources for Mechanical Circulatory Support: A Computational Proof-of-Concept Study

    OpenAIRE

    Biasetti, Jacopo; Pustavoitau, Aliaksei; Spazzini, Pier Giorgio

    2017-01-01

    Mechanical circulatory support devices, such as total artificial hearts and left ventricular assist devices, rely on external energy sources for their continuous operation. Clinically approved power supplies rely on percutaneous cables connecting an external energy source to the implanted device with the associated risk of infections. One alternative, investigated in the 70s and 80s, employs a fully implanted nuclear power source. The heat generated by the nuclear decay can be converted into ...

  16. Treatment Outcome of Two Adjacent Implant-Supported Restorations with Different Implant Platform Designs in the Esthetic Region : A Five-Year Randomized Clinical Trial

    NARCIS (Netherlands)

    Van Nimwegen, Wouter G.; Raghoebar, Gerry M.; Stellingsma, Kees; Tymstra, Nynke; Vissink, Arjan; Meijer, Henny J. A.

    Purpose: The aim of this study was to evaluate the peri-implant soft and hard tissues and satisfaction in patients with two adjacent implant-supported restorations in the esthetic region, treated with two adjacent implants with a scalloped or flat platform. Materials and Methods: The randomized

  17. Connective tissue grafts for thickening peri-implant tissues at implant placement. One-year results from an explanatory split-mouth randomised controlled clinical trial.

    Science.gov (United States)

    Wiesner, Günter; Esposito, Marco; Worthington, Helen; Schlee, Markus

    2010-01-01

    Nothing to declare. To evaluate whether connective tissue grafts performed at implant placement could be effective in augmenting peri-implant soft tissues. Ten partially edentulous patients requiring at least one single implant in the premolar or molar areas of both sides of the mandible were randomised to have one side augmented at implant placement with a connective soft tissue graft harvested from the palate or no augmentation. After 3 months of submerged healing, abutments were placed and within 1 month definitive crowns were permanently cemented. Outcome measures were implant success, any complications, peri-implant marginal bone level changes, patient satisfaction and preference, thickness of the soft tissues and aesthetics (pink aesthetic score) evaluated by an independent and blinded assessor 1 year after loading. One year after loading, no patients dropped out, no implants failed and no complications occurred. Both groups lost statistically significant amounts of peri-implant bone 1 year after loading (0.8 mm in the grafted group and 0.6 mm in the non-grafted group), but there was no statistically significant difference between groups. Soft tissues at augmented sites were 1.3 mm thicker (P Connective tissue grafts are effective in increasing soft tissue thickness, thus improving aesthetics. Longer follow-ups are needed to evaluate the stability of peri-implant tissues over time.

  18. 3DII implantation effect on corrosion properties of the AISI/SAE 1020 steel

    Energy Technology Data Exchange (ETDEWEB)

    Dulce M., H.J.; Rueda V., Alejandro [Universidad Francisco de Paula Santander, A.A. 1055, Cucuta (Colombia); Dougar-Jabon, Valeri [Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia)

    2005-08-01

    The three dimensional ion implantation technology (3DII) is one of the methods of improving the tribological characteristics and resistance to hydrogen embrittlement processes in metals. In this report, some results concerning the resistance effect of nitrogen ion implantation to oxidation of the sample, made of AISI/SAE 1020 steel, are given. The nitrogen ions were implanted in the discharge chamber of the JUPITER reactor. Both the treated and untreated samples were tested through potential-static measurements, which permitted to determine the corrosion current, the slopes that characterise the braking level of anode and cathode reactions. The polarization resistance near the corrosion potential is calculated. The results of the study encourage to consider the nitrogen ion implantation in high voltage and low pressure discharges as one of the methods of anticorrosive protection which do not change the geometric configuration of the treated steel pieces. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. A 5- to 8-year retrospective study comparing the clinical results of implant-supported telescopic crown versus bar overdentures in patients with edentulous maxillae.

    Science.gov (United States)

    Zou, Duohong; Wu, Yiqun; Huang, Wei; Zhang, Zhiyong; Zhang, Zhiyuan

    2013-01-01

    The objective of this study was to compare implant survival and success rates, peri-implant parameters, and prosthodontic maintenance efforts for implant-supported telescopic crown overdentures and bar overdentures to restore maxillary edentulism. This retrospective clinical study involved patients with maxillary edentulism who were fitted with implant-supported overdentures from January 2004 to June 2007. During a 5- to 8-year follow-up period, the implant survival and success rates, biologic and mechanical complications, prosthodontic maintenance, and patient satisfaction were retrospectively analyzed. The data were evaluated statistically and P overdentures. Twenty-one patients chose telescopic crown overdentures and 23 patients chose bar overdentures. A total of 41 patients and 201 implants were available for follow-up. The implant survival and success rates, average bone resorption, and subjective patient satisfaction scores showed no difference between the telescopic crown and the bar overdenture group at follow-up. However, there were higher values for Plaque and Calculus Indexes in the bar group compared with the telescopic crown group, and these values showed a statistically significant difference annually from the 3-year follow-up (P overdentures provided a healthy peri-implant structure for implants in both groups. Implant-supported telescopic crown or bar overdentures can provide a good treatment option for patients with edentulous maxillae.

  20. Remodeling of the Mandibular Bone Induced by Overdentures Supported by Different Numbers of Implants.

    Science.gov (United States)

    Li, Kai; Xin, Haitao; Zhao, Yanfang; Zhang, Zhiyuan; Wu, Yulu

    2016-05-01

    The objective of this study was to investigate the process of mandibular bone remodeling induced by implant-supported overdentures. computed tomography (CT) images were collected from edentulous patients to reconstruct the geometry of the mandibular bone and overdentures supported by implants. Based on the theory of strain energy density (SED), bone remodeling models were established using the user material subroutine (UMAT) in abaqus. The stress distribution in the mandible and bone density change was investigated to determine the effect of implant number on the remodeling of the mandibular bone. The results indicated that the areas where high Mises stress values were observed were mainly situated around the implants. The stress was concentrated in the distal neck region of the distal-most implants. With an increased number of implants, the biting force applied on the dentures was almost all taken up by implants. The stress and bone density in peri-implant bone increased. When the stress reached the threshold of remodeling, the bone density began to decrease. In the posterior mandible area, the stress was well distributed but increased with decreased implant numbers. Changes in bone density were not observed in this area. The computational results were consistent with the clinical data. The results demonstrate that the risk of bone resorption around the distal-most implants increases with increased numbers of implants and that the occlusal force applied to overdentures should be adjusted to be distributed more in the distal areas of the mandible.

  1. Refusal of implant supported mandibular overdentures by elderly patients.

    Science.gov (United States)

    Ellis, Janice S; Levine, Alissa; Bedos, Christophe; Mojon, Phillippe; Rosberger, Zeer; Feine, Jocelyne; Thomason, J Mark

    2011-03-01

      The aim of this study was to gain greater in-depth understanding of why elderly patients who are currently dissatisfied with conventional dentures decline implant treatment.   There is strong evidence from high-quality randomised controlled trials to support the use of implant-supported overdentures for the restoration of the edentulous mandible. However, whilst recruiting for randomised clinical trials, researchers have found that a high proportion of potential subjects decline participation, despite the removal of financial constraints.   The study adopted a qualitative approach to provide a rich and deep understanding of people's reasons for refusal. Data were collected through focus group interviews in a two-centre study based in Montreal, Canada and Newcastle, UK. A semi-structured interview schedule was used and iteratively developed as analysis identified themes from previous focus groups. Transcripts of focus groups were coded and emergent themes determined.   Two main themes emerged; patients' fear and anxiety (relating to the pain of surgery, complications of the procedure and immediate post-surgical denture use), and the appropriateness of the procedure in an elderly person.   Fears of pain, complications and social embarrassment, exacerbated by age, are important factors that help explain refusal of implants by elderly patients. © 2010 The Gerodontology Society and John Wiley & Sons A/S.

  2. Cataract Surgery with Foldable Single Piece IOLs in Congenital Cataract-Microcornea Syndrome

    Directory of Open Access Journals (Sweden)

    Niphon Chirapapaisan, M.D.

    2017-11-01

    Full Text Available Objective: To present the visual outcomes and intraocular lens (IOLs stability after cataract surgery with foldable single piece IOLs in a patient with congenital cataract-microcornea syndrome (CCMC. Case presentation: A 28-year-old woman presented with bilateral microcornea and posterior polar cataract. Her uncorrected (UDVA and corrected (CDVA distance visual acuities were 20/100, 20/160 and 20/80, 20/80, respectively. The horizontal cornea diameter was 9.0 mm in both eyes. Anterior chamber angle assessment (ACAA with Scheie classification showed grade 3 on the superior, inferior, and temporal site and grade 2 on the nasal site in both eyes. On ultrasound biomicroscopy (UBM, the anterior chamber depths were 2.35 mm. OD and 2.41 mm. OS. The axial lengths were 23.28 mm., OD and 22.50 mm. OS with the A-scan ultrasound biometry. The IOLs power calculation with SRK/T formulas was +25.00 diopter OD and +22.50 diopter OS (A-constant 118.4. Phacoemulsification was performed on both eyes. After lens aspiration, ruptured posterior capsule, a common complication occurred. Then anterior vitrectomy was performed. A foldable single piece IOLs without haptic trimming was implanted in the sulcus in each eye. CDVA was 20/63 equally in both eyes. The intraocular pressure was 12 and 14 mmHg. ACAA showed grade 2 and no pigment dispersion. The IOLs had no tilt or decentration. UBM showed the IOLs were in the proper position and were not rubbing the iris. Conclusion: The foldable single piece IOLs without haptic trimming in the sulcus were safely implanted in both eyes with microcornea in CCMC.

  3. [A phd completed 10. Implant-supported removable partial -dentures in a Kennedy Class I-situation in the mandible].

    Science.gov (United States)

    Jensen-Louwerse, C

    2017-06-01

    Implant-supported removable partial dentures in the mandible often cause problems, which means that patients wear their dentures seldom if at all. A solution is to place implants that the dentures can be snapped onto. There is, however, no consensus about the best position of the implants in the mandible yet. In addition, it is worthwhile to balance the cost of treatment with its effectiveness. In a randomised cross-over clinical trial involving 30 patients with a shortened dental arch, the implant-supported removable partial denture in the mandible was evaluated based on the experience of the patient, mean time of wearing, chewing ability and the clinical and radiographic parameters in relation to 2 different implant positions: 2 in the pre-molar region or 2 in the molar region. The cost-effectiveness of both treatments was also evaluated. From the patient's point of view, the implant-supported removable partial dentures are best supported by implants placed in the molar region. The research also revealed, however, that significantly more bleeding occurred around implants placed in the molar region and from a clinical perspective placement in the pre-molar region would have preference. The cost-effectiveness of the treatment with an implant-supported removable partial denture depends on the choice of outcome measurement and monetary threshold.

  4. Large area spark chamber and support, and method of recording and analyzing the information on a radioactive work piece

    International Nuclear Information System (INIS)

    Britten, R.J.; Davidson, E.H.

    1985-01-01

    Novel large area spark chamber having a support for carrying a generally planar, radioactive work piece. The spark chamber has a thin window which is either a rigid plastic sheet carrying a thin layer of an electrically conductive material on the surface thereof, or a thin planar piece or film of electrically conductive metal. There is positioned in superposed relationship to the thin window, a layer of semi-conducting glass in spaced-apart relationship from the thin window by a resilient insulating seal to form an enclosed gas retaining chamber. An electrically conducting surface is adhered to the upper surface of the layer of semi-conducting glass. An electrically conductive path is provided between the thin layer of electrically conductive material on the thin window and the electrically conducting surface on said semi-conducting glass. The electrically conductive path includes a high voltage supply and TDCs and ADCs. There are also means for detecting the location of sites of impingement of radiation on the electrically conducting surface of the semi-conducting glass, and means for recording and analyzing the information present on the work piece

  5. Effect of joining the sectioned implant-supported prosthesis on the peri-implant strain generated in simulated mandibular model

    Directory of Open Access Journals (Sweden)

    Ipsha Singh

    2017-01-01

    Full Text Available Aim: The aim of this study is to evaluate the strain developed in simulated mandibular model before and after the joining of an implant-supported screw-retained prosthesis by different joining techniques, namely, arc welding, laser welding, and soldering. Materials and Methods: A specimen simulating a mandibular edentulous ridge was fabricated in heat-cured acrylic resin. 4-mm holes were drilled in the following tooth positions; 36, 33, 43, 46. Implant analogs were placed in the holes. University of California, Los Angeles, abutment was attached to the implant fixture. Eight strain gauges were attached to the acrylic resin model. Six similar models were made. Implant-supported screw-retained fixed prosthesis was fabricated in nickel-chromium alloy. A load of 400 N was applied on the prosthesis using universal testing machine. Resultant strain was measured in each strain gauge. All the prostheses were sectioned at the area between 36 and 33, 33 and 43, and 43 and 46 using 35 micrometer carborundum disc, and strain was measured in each strain gauge after applying a load of 400 N on the prosthesis. Specimens were joined by arc welding, soldering, and laser welding. After joining, a load of 400 N was applied on each prosthesis and the resultant strain was measured in each strain gauge. Results: Highest mean strain values were recorded before sectioning of the prostheses (889.9 microstrains. Lowest mean strain values were recorded after sectioning the prosthesis and before reuniting it (225.0 microstrains. Conclusions: Sectioning and reuniting the long-span implant prosthesis was found to be a significant factor in influencing the peri-implant strain.

  6. Role of Steric Hindrance in the Crystal Packing of Z′ = 4 Superstructure of Trimethyltin Hydroxide

    KAUST Repository

    Dey, S.

    2018-01-22

    The roomerature crystal structure of trimethyltin hydroxide, (CH)SnOH, has been described by Anderson et al. [Cryst. Growth Des. 2011, 11, 820-826] as a 2a × 2b × 8c, 32-fold superstructure. We report a a × b × 8c, eight-fold superstructure with orthorhombic P2cn symmetry and Z′ = 4. Structured diffuse scattering observed at the positions of presumed superlattice reflections along a∗ and b∗ might have appeared as Bragg reflections in the experiment by Anderson et al. Alternatively, Anderson et al. and the present work might have studied different polymorphs of (CH)SnOH. Crystalline (CH)SnOH constitutes polymeric chains arranged parallel to c. In the eight-fold superstructure at 220 K, the polymeric chains possess a distorted zigzag arrangement of linked linear O-Sn-O units with bent angle at oxygen of ∼139.2°. This structure is essentially different from the 8-helical arrangement in the published 32-fold superstructure model. The origin of the distorted zigzag structure is explained by steric hindrance between hydrogen atoms of adjacent hydroxy groups and (CH)Sn groups. Frustration in the packing of the chains is determined by steric hindrance between methyl groups of neighboring chains, which prevents the formation of interchain C-H···O hydrogen bonds.

  7. Bone-repair properties of biodegradable hydroxyapatite nano-rod superstructures

    Science.gov (United States)

    D'Elía, Noelia L.; Mathieu, Colleen; Hoemann, Caroline D.; Laiuppa, Juan A.; Santillán, Graciela E.; Messina, Paula V.

    2015-11-01

    Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures for the in vitro conditions of bone-repair. Experiments are underway to investigate the effects of the material microstructure, surface roughness and hydrophilicity on their osseo-integration, osteo-conduction and osteo-induction abilities. Materials were tested in the presence of both, rat primary osteoblasts and rabbit mesenchymal stem cells. The following aspects are discussed: (i) cytotoxicity and material degradation; (ii) rat osteoblast spreading, proliferation and differentiation; and (iii) rabbit mesenchymal stem cell adhesion on nano-HAp and nano-HAp/collagen type I coatings. We effectively prepared a material based on biomimetic HAp nano-rods displaying the appropriate surface topography, hydrophilicity and degradation properties to induce the in vitro desired cellular responses for bone bonding and healing. Cells seeded on the selected material readily attached, proliferated and differentiated, as confirmed by cell viability, mitochondrial metabolic activity, alkaline phosphatase (ALP) activity and cytoskeletal integrity analysis by immunofluorescence localization of alpha-smooth muscle actin (α-SMA) protein. These results highlight the influence of material's surface characteristics to determine their tissue regeneration potential and their future use in engineering osteogenic scaffolds for orthopedic implants.Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures

  8. Clinical Evaluation of Implant-Supported Removable Partial Dentures With a Stress-Breaking Attachment.

    Science.gov (United States)

    Suzuki, Yasunori; Kono, Kentaro; Shimpo, Hidemasa; Sato, Yohei; Ohkubo, Chikahiro

    2017-08-01

    The stress-breaking ball (SBB) attachment can distribute the occlusal force equally between the alveolar ridge and the implants. The purpose of this study was to evaluate the implant-supported distal extension removable partial dentures (RPDs) with SBB attachment in 10 patients who were partially edentulous. This randomized crossover study was designed to compare the function of RPDs with and without healing abutments and SBB attachments to support the posterior aspects of the RPDs. Mandibular jaw movements during mastication and the occlusal force and contact area were measured with a commercially available tracking device and pressure-sensitive sheets. Using a visual analog scale, 4 criteria-chewing, retention, stability, and comfort-were evaluated. All of the data obtained were analyzed using a 1-way analysis of variance (α = 0.05). There were no significant differences in either the mean time or the coefficient of variation among the SBB attachments and healing abutments of implant-supported removable partial dentures (ISRPDs) and conventional removable partial dentures (CRPDs). SBB attachments and healing abutments of ISRPDs had greater forces and contact areas than those of CRPDs with significant differences. For all criteria, patients preferred SBB attachments to healing abutments and CRPDs. The implant-supported distal extension RPDs with SBB attachment improved denture stability and patients' satisfaction.

  9. One-time versus repeated abutment connection for platform-switched implant: A systematic review and meta-analysis.

    Science.gov (United States)

    Wang, Qing-Qing; Dai, Ruoxi; Cao, Chris Ying; Fang, Hui; Han, Min; Li, Quan-Li

    2017-01-01

    This review aims to compare peri-implant tissue changes in terms of clinical and radiographic aspects of implant restoration protocol using one-time abutment to repeated abutment connection in platform switched implant. A structured search strategy was applied to three electronic databases, namely, Pubmed, Embase and Web of Science. Eight eligible studies, including seven randomised controlled studies and one controlled clinical study, were identified in accordance with inclusion/exclusion criteria. Outcome measures included peri-implant bone changes (mm), peri-implant soft tissue changes (mm), probing depth (mm) and postsurgical complications. Six studies were pooled for meta-analysis on bone tissue, three for soft tissue, two for probing depth and four for postsurgical complications. A total of 197 implants were placed in one-time abutment group, whereas 214 implants were included in repeated abutment group. The implant systems included Global implants, Ankylos, JDEvolution (JdentalCare), Straumann Bone level and Conelog-Screwline. One-time abutment group showed significantly better outcomes than repeated abutment group, as measured in the standardised differences in mean values (fixed- and random-effect model): vertical bone change (0.41, 3.23) in 6 months, (1.51, 14.81) in 12 months and (2.47, 2.47) in 3 years and soft tissue change (0.21, 0.23). No significant difference was observed in terms of probing depth and complications. Our meta-analysis revealed that implant restoration protocol using one-time abutment is superior to repeated abutment for platform switched implant because of less bone resorption and soft tissue shifts in former. However, future randomised clinical trials should be conducted to further confirm these findings because of the small samples and the limited quality of the original research.

  10. Coherent Synchrotron-Based Micro-Imaging Employed for Studies of Micro-Gap Formation in Dental Implants

    International Nuclear Information System (INIS)

    Rack, T.; Stiller, M.; Nelson, K.; Zabler, S.; Rack, A.; Riesemeier, H.; Cecilia, A.

    2011-01-01

    Biocompatible materials such as titanium are regularly applied in oral surgery. Titanium-based implants for the replacement of missing teeth demand a high mechanical precision in order to minimize micro-bacterial leakage, especially when two-piece concepts are used. Synchrotron-based hard x-ray radiography, unlike conventional laboratory radiography, allows high spatial resolution in combination with high contrast even when micro-sized features in such highly attenuating objects are visualized. Therefore, micro-gap formation at interfaces in two-piece dental implants with the sample under different mechanical loads can be studied. We show the existence of micro-gaps in implants with conical connections and study the mechanical behavior of the mating zone of conical implants during loading. The micro-gap is a potential source of implant failure, i.e., bacterial leakage, which can be a stimulus for an inflammatory process.

  11. Increased crown-to-implant ratio may not be a risk factor for dental implant failure under appropriate plaque control.

    Science.gov (United States)

    Okada, Shinsuke; Koretake, Katsunori; Miyamoto, Yasunari; Oue, Hiroshi; Akagawa, Yasumasa

    2013-01-01

    The aim of this study was to evaluate whether increased crown-to-implant (C/I) ratio influences implant stability or not under proper healthy control of peri-implant mucosa. The hypothesis of this study is that implant stability can be maintained despite High C/I, under appropriate plaque control. Five male Beagle-Labrador hybrid dogs (2 years old) were used. Their bilateral mandibular premolar extraction was performed. After allowing 12 weeks for bone healing, 3 types of vertical marginal bone loss were simultaneously prepared randomly. Then, 30 titanium implants were placed in the edentulous areas and defined as High C/I, Mid C/I and Low C/I groups. This time point was designated as the baseline (0 Week). Twelve weeks after implant placement, metal superstructures were cemented to the implants and an occlusal plate was set at the opposite side. At the same time, Calcein green was injected for remodeling evaluation. Implants were loaded by feeding the dogs a hard pellet diet. Tooth brushing was performed 5 days per week during the study to maintain healthy peri-implant mucosa. Twenty-four weeks following implant placement, the interface structure was evaluated clinically, radiologically, and histologically. Implant stability quotient (ISQ) increased with time in all 3 groups, without any significant correlation with the C/I value (p >0.05). Moreover, mean marginal bone loss adjacent around implants in all 3 groups ranged between 0.11 and 0.19 mm, with no significant difference (p >0.05). Many fluorescence-labeled bones are shown in the High C/I group. It is considered that high remodeling activity prevent marginal bone loss in the High C/I group and this may provide favorable implant stability under proper plaque control. These findings suggest that increased C/I may not be a risk factor for implant failure if the peri-implant mucosa is kept healthy, as was the case in this animal model.

  12. Increased crown-to-implant ratio may not be a risk factor for dental implant failure under appropriate plaque control.

    Directory of Open Access Journals (Sweden)

    Shinsuke Okada

    Full Text Available OBJECTIVE: The aim of this study was to evaluate whether increased crown-to-implant (C/I ratio influences implant stability or not under proper healthy control of peri-implant mucosa. The hypothesis of this study is that implant stability can be maintained despite High C/I, under appropriate plaque control. MATERIALS AND METHODS: Five male Beagle-Labrador hybrid dogs (2 years old were used. Their bilateral mandibular premolar extraction was performed. After allowing 12 weeks for bone healing, 3 types of vertical marginal bone loss were simultaneously prepared randomly. Then, 30 titanium implants were placed in the edentulous areas and defined as High C/I, Mid C/I and Low C/I groups. This time point was designated as the baseline (0 Week. Twelve weeks after implant placement, metal superstructures were cemented to the implants and an occlusal plate was set at the opposite side. At the same time, Calcein green was injected for remodeling evaluation. Implants were loaded by feeding the dogs a hard pellet diet. Tooth brushing was performed 5 days per week during the study to maintain healthy peri-implant mucosa. Twenty-four weeks following implant placement, the interface structure was evaluated clinically, radiologically, and histologically. RESULT: Implant stability quotient (ISQ increased with time in all 3 groups, without any significant correlation with the C/I value (p >0.05. Moreover, mean marginal bone loss adjacent around implants in all 3 groups ranged between 0.11 and 0.19 mm, with no significant difference (p >0.05. Many fluorescence-labeled bones are shown in the High C/I group. It is considered that high remodeling activity prevent marginal bone loss in the High C/I group and this may provide favorable implant stability under proper plaque control. CONCLUSION: These findings suggest that increased C/I may not be a risk factor for implant failure if the peri-implant mucosa is kept healthy, as was the case in this animal model.

  13. Cost-effectiveness of implant-supported mandibular removable partial dentures

    NARCIS (Netherlands)

    Jensen, Charlotte; Ross, Jamila; Feenstra, Talitha L; Raghoebar, Gerry M; Speksnijder, Caroline; Meijer, Henny J A; Cune, Marco S

    ObjectivesThe aim of this study was to conduct a cost-effectiveness analysis comparing conventional removable partial dentures (RPDs) and implant-supported RPDs (ISRPDs) treatment in patients with an edentulous maxilla and a bilateral free-ending situation in the mandible. Material and methodsThirty

  14. Comparison of posterior capsule folds following intracapsular implantation of three types of intraocular lenses with different haptic design

    Directory of Open Access Journals (Sweden)

    Ling-Lin Zhang

    2018-04-01

    Full Text Available AIM: To compare the incidence of posterior capsule folds among different types of intraocular lens(IOLto determine risk factors of posterior capsule folds. METHODS:It was a retrospective study. We collected the cases in which the patients underwent phacoemulsification(PHACOand IOL implantation and at least one of the three types of IOL was implanted, including 2-haptic 3-piece IOLs(HOYA PY60AD, 4-haptic 1-piece IOLs(Bausch & Lomb AO, 2-haptic 1-piece IOLs(AMO Tecnis ZCB00. The posterior capsule folds were measured using slit lamp microscope 2d after the surgery. Information of patient's age, gender, length of ocular axis, intraocular pressure, types of IOL were recorded. Posterior capsule fold risk indicators were identified by using logistic regression analysis. RESULTS: One hundred eighty-seven patients(242 eyeshad been collected, including 80 eyes implanted with HOYA PY60AD IOLs, 81 eyes implanted with Bausch & Lomb AO IOLs, 81 eyes implanted with AMO Tecnis ZCB00 IOLs. The incidence of posterior capsule folds of patients implanted with HOYA PY60AD IOLs was significantly higher than those of patients implanted with AMO Tecnis ZCB00 IOLs(56.3% vs 38.3%, P=0.027. While the incidence of patients implanted with Bausch & Lomb AO IOLs was significantly lower than those of patients implanted with AMO Tecnis ZCB00 IOLs(14.8% vs 38.3%, P=0.001. Multi-factor logistics regression analysis demonstrated that independent risk factors were type of IOLs and length of ocular axis. Compared with AMO Tecnis ZCB00 IOLs, using HOYA PY60AD IOLs increased the risk of posterior capsule folds \\〖P=0.020, OR(95%CI=2.145(1.129,4.073\\〗, while using Bausch & Lomb AO IOLs reduced the risk \\〖P=0.001, OR(95%CI=0.274(0.127, 0.591\\〗. Shorter ocular axis might increase the risk of posterior capsule folds \\〖P=0.012, OR(95%CI=0.669(0.489, 0.915\\〗. CONCLUSION: Haptic design should be an important consideration in IOL design. Compared with AMO Tecnis ZCB00 IOLs

  15. Effect of implant support on mandibular distal extension removable partial dentures: relationship between denture supporting area and stress distribution.

    Science.gov (United States)

    Sato, Maki; Suzuki, Yasunori; Kurihara, Daisuke; Shimpo, Hidemasa; Ohkubo, Chikahiro

    2013-04-01

    This study explored the relationship between implant support and the denture-supporting area by comparing the stability of an implant-supported distal extension removable partial denture and a conventional distal extension removable partial denture. A model simulating a mandibular bilateral distal extension missing (#34-37 and #44-47) was fabricated using silicone impression material as soft tissue (2 mm thick) on an epoxy resin bone model. The denture base was reduced by 5 mm cutting part of both the retromolar pad and the lingual border. Loads of up to 5 kg were applied, and the pressure and displacement of the RPDs were simultaneously measured and analyzed using the Wilcoxon test (αremovable partial denture (ISRPD) was significantly less than on the conventional RPD (CRPD). As the supporting area of the denture base decreased, the pressure and the denture displacement of the CRPD were greater than for the ISRPD. This study indicated that implant placement at the distal edentulous ridge can prevent denture displacement of the distal extension bases, regardless of the supporting area of the denture base. Copyright © 2013 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  16. Enigmatic cranial superstructures among Chamorro ancestors from the Mariana Islands: gross anatomy and microanatomy.

    Science.gov (United States)

    Heathcote, Gary M; Bromage, Timothy G; Sava, Vincent J; Hanson, Douglas B; Anderson, Bruce E

    2014-06-01

    This study focuses on the gross anatomy, anatomic relations, microanatomy, and the meaning of three enigmatic, geographically patterned, and quasi-continuous superstructures of the posterior cranium. Collectively known as occipital superstructures (OSSs), these traits are the occipital torus tubercle (TOT), retromastoid process (PR), and posterior supramastoid tubercle (TSP). When present, TOT, PR, and TSP develop at posterior cranial attachment sites of the upper trapezius, superior oblique, and sternocleidomastoid muscles, respectively. Marked expression and co-occurrence of these OSSs are virtually circumscribed within Oceania and reach highest recorded frequencies in protohistoric Chamorros (CHamoru) of the Mariana Islands. Prior to undertaking scanning electron microscopy (SEM) work, our working multifactorial model for OSS development was that early-onset, long-term, and chronic activity-related microtrauma at enthesis sites led to exuberant reactive or reparative responses in a substantial minority of genetically predisposed (and mostly male) individuals. SEM imaging, however, reveals topographic patterning that questions, but does not negate, activity induction of these superstructures. Although OSSs appear macroscopically as relatively large and discrete phenomena, SEM findings reveal a unique, widespread, and seemingly systemic distribution of structures over the occipital surface that have the appearance of OSS microforms. Nevertheless, apparent genetic underpinnings, anatomic relationships with muscle entheses, and positive correlation of OSS development with humeral robusticity continue to suggest that these superstructures have potential to at once bear witness to Chamorro population history and inform osteobiographical constructions of chronic activity patterns in individuals bearing them. Further work is outlined that would illuminate the proximate and ultimate meanings of OSS. Copyright © 2014 Wiley Periodicals, Inc.

  17. Investigation of the implant-supported overdentures in completely edentulous mandibles

    Directory of Open Access Journals (Sweden)

    Yu-Hwa Pan

    2015-12-01

    Conclusion: Our results indicate that implant-supported overdentures provide a reliable and effective alternative to conventional complete mandibular dentures. Overdentures with Hader bars and bilateral, cast ERA attachments resulted in fewer prosthetic complications.

  18. Electropolished Titanium Implants with a Mirror-Like Surface Support Osseointegration and Bone Remodelling

    Directory of Open Access Journals (Sweden)

    Cecilia Larsson Wexell

    2016-01-01

    Full Text Available This work characterises the ultrastructural composition of the interfacial tissue adjacent to electropolished, commercially pure titanium implants with and without subsequent anodisation, and it investigates whether a smooth electropolished surface can support bone formation in a manner similar to surfaces with a considerably thicker surface oxide layer. Screw-shaped implants were electropolished to remove all topographical remnants of the machining process, resulting in a thin spontaneously formed surface oxide layer and a smooth surface. Half of the implants were subsequently anodically oxidised to develop a thickened surface oxide layer and increased surface roughness. Despite substantial differences in the surface physicochemical properties, the microarchitecture and the composition of the newly formed bone were similar for both implant surfaces after 12 weeks of healing in rabbit tibia. A close spatial relationship was observed between osteocyte canaliculi and both implant surfaces. On the ultrastructural level, the merely electropolished surface showed the various stages of bone formation, for example, matrix deposition and mineralisation, entrapment of osteoblasts within the mineralised matrix, and their morphological transformation into osteocytes. The results demonstrate that titanium implants with a mirror-like surface and a thin, spontaneously formed oxide layer are able to support bone formation and remodelling.

  19. Fracture Strength of Three-Unit Implant Supported Fixed Partial Dentures with Excessive Crown Height Fabricated from Different Materials

    Directory of Open Access Journals (Sweden)

    Vahideh Nazari

    2017-01-01

    Full Text Available Objectives: Fracture strength is an important factor influencing the clinical long-term success of implant-supported prostheses especially in high stress situations like excessive crown height space (CHS. The purpose of this study was to compare the fracture strength of implant-supported fixed partial dentures (FPDs with excessive crown height, fabricated from three different materials.Materials and Methods: Two implants with corresponding abutments were mounted in a metal model that simulated mandibular second premolar and second molar. Thirty 3-unit frameworks with supportive anatomical design were fabricated using zirconia, nickel-chromium alloy (Ni-Cr, and polyetheretherketone (PEEK (n=10. After veneering, the CHS was equal to 15mm. Then; samples were axially loaded on the center of pontics until fracture in a universal testing machine at a crosshead speed of 0.5 mm/minute. The failure load data were analyzed by one-way ANOVA and Games-Howell tests at significance level of 0.05.Results: The mean failure loads for zirconia, Ni-Cr and PEEK restorations were 2086±362N, 5591±1200N and 1430±262N, respectively. There were significant differences in the mean failure loads of the three groups (P<0.001. The fracture modes in zirconia, metal ceramic and PEEK restorations were cohesive, mixed and adhesive type, respectively.Conclusions: According to the findings of this study, all implant supported three-unit FPDs fabricated of zirconia, metal ceramic and PEEK materials are capable to withstand bite force (even para-functions in the molar region with excessive CHS.Keywords: Dental Implants; Polyetheretherketone; Zirconium oxide; Dental Restoration Failure; Dental Porcelain

  20. Placement of single tooth implant in healed socket with immediate temporization: Clinical study

    Directory of Open Access Journals (Sweden)

    Jeevan Lata

    2012-01-01

    Full Text Available Introduction: Edentulous condition inadequately compensated for, by dentures, impair oral function and is accompanied by reduced self–confidence. In a continued effort to achieve these goals, implant dentistry was introduced. Immediate temporization is somehow a recent concept, which allows the maintenance of soft tissue contours, along with interdental alveolar contours. Aims and Obectives: Aims of the present study were to study the placement of implant in the post-extracted healed tooth socket of anterior maxilla and to evaluate the feasibility of early function on implants placed. Materials and Methods: In the present study, HI-TECH IMPLANTS TRX-OP one-piece immediate loading implant system with the built on abutment has been used.Immediate temporisation has been done and results have been evaluated in terms of stability, gingival health, esthetics, marginal bone loss, patient′s psychological attitude, and satisfaction.
Results: Out of eight implants, 6 successfully healed whereas 2 implants suffered failure
Conclusion: Overall conclusion drawn from the study is, immediate temporization is a successful method providing psychological, financial and emotional benefits to the patient.

  1. Treatment Outcome and Patient Satisfaction with Two Adjacent Implant-Supported Restorations in the Esthetic Zone

    NARCIS (Netherlands)

    Tymstra, Nynke; Meijer, Henny J. A.; Stellingsma, Kees; Raghoebar, Gerry M.; Vissink, Arjan

    2010-01-01

    The purpose of this study was to evaluate the clinical and radiographic parameters as well as the esthetic outcome of two adjacent implant-supported restorations and the surrounding peri-implant mucosa in the maxillary esthetic zone. Ten patients were treated with two adjacent implants in the

  2. Chewing efficiency, bite force and oral health-related quality of life with narrow diameter implants - a prospective clinical study: results after one year.

    Science.gov (United States)

    Enkling, Norbert; Saftig, Marcus; Worni, Andreas; Mericske-Stern, Regina; Schimmel, Martin

    2017-04-01

    This prospective study aimed to investigate the evolution of chewing efficiency, maximum voluntary bite force (MBF) and oral health-related quality of life (OHRQoL) in edentulous patients treated with narrow diameter implants (NDIs) over the course of 1 year. Four NDIs (MDI ® , 3M ESPE, diameter 1.8 mm) were placed interforaminally in 20 edentulous patients. They were immediately loaded by converting the existing prosthesis into an implant overdenture. Participants were examined six times pre- and postoperatively [baseline (BL) to week 52 (w52)]. Chewing efficiency was evaluated with a colour-mixing ability test by evaluation of the standard deviation of hue (VOH, ViewGum©). MBF was measured using a digital force gauge. OHRQoL was determined with the Oral Health Impact Profile (OHIPG49). Nonparametric Brunner-Langer models were applied for statistical testing. The study failed to demonstrate an effect on chewing efficiency. MBF increased continuously during the observation period (medians: MBF[N]@BL = 46.6 [iqr 50.1]; MBF[N]@w52 = 103.9 [iqr 76.0]; P = 0.002). OHRQoL increased steeply after implant loading and continued improving (medians: BL ∑OHIPG49 = 31 [iqr 40.0]; w4 ∑OHIPG49 = 11.5 [iqr 19.5]; w52 ∑OHIPG49 = 6 [iqr 13.0], P chewing instructions. Larger studies need to confirm a positive effect on chewing efficiency and develop long-term maintenance solutions if patients become frail because no easy downgrading approaches of one-piece titanium implants exist. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Effect of joining the sectioned implant-supported prosthesis on the peri-implant strain generated in simulated mandibular model

    OpenAIRE

    Ipsha Singh; K Chandrasekharan Nair; Jayakar Shetty

    2017-01-01

    Aim: The aim of this study is to evaluate the strain developed in simulated mandibular model before and after the joining of an implant-supported screw-retained prosthesis by different joining techniques, namely, arc welding, laser welding, and soldering. Materials and Methods: A specimen simulating a mandibular edentulous ridge was fabricated in heat-cured acrylic resin. 4-mm holes were drilled in the following tooth positions; 36, 33, 43, 46. Implant analogs were placed in the holes. Un...

  4. Randomized clinical trial of implant-supported ceramic-ceramic and metal-ceramic fixed dental prostheses: preliminary results.

    Science.gov (United States)

    Esquivel-Upshaw, Josephine F; Clark, Arthur E; Shuster, Jonathan J; Anusavice, Kenneth J

    2014-02-01

    The aim of this study was to determine the survival rates over time of implant-supported ceramic-ceramic and metal-ceramic prostheses as a function of core-veneer thickness ratio, gingival connector embrasure design, and connector height. An IRB-approved, randomized, controlled clinical trial was conducted as a single-blind pilot study involving 55 patients missing three teeth in either one or two posterior areas. These patients (34 women; 21 men; age range 52-75 years) were recruited for the study to receive a three-unit implant-supported fixed dental prosthesis (FDP). Two implants were placed for each of the 72 FDPs in the study. The implants (Osseospeed, Astra Tech), which were made of titanium, were grit blasted. A gold-shaded, custom-milled titanium abutment (Atlantis, Astra Tech), was secured to each implant body. Each of the 72 FDPs in 55 patients were randomly assigned based on one of the following options: (1) A. ceramic-ceramic (Yttria-stabilized zirconia core, pressable fluorapatite glass-ceramic, IPS e.max ZirCAD, and ZirPress, Ivoclar Vivadent) B. metal-ceramic (palladium-based noble alloy, Capricorn, Ivoclar Vivadent, with press-on leucite-reinforced glass-ceramic veneer, IPS InLine POM, Ivoclar Vivadent); (2) occlusal veneer thickness (0.5, 1.0, and 1.5 mm); (3) curvature of gingival embrasure (0.25, 0.5, and 0.75 mm diameter); and (4) connector height (3, 4, and 5 mm). FDPs were fabricated and cemented with dual-cure resin cement (RelyX, Universal Cement, 3M ESPE). Patients were recalled at 6 months, 1 year, and 2 years. FDPs were examined for cracks, fracture, and general surface quality. Recall exams of 72 prostheses revealed 10 chipping fractures. No fractures occurred within the connector or embrasure areas. Two-sided Fisher's exact tests showed no significant correlation between fractures and type of material system (p = 0.51), veneer thickness (p = 0.75), radius of curvature of gingival embrasure (p = 0.68), and connector height (p = 0

  5. Comparison of Three Attachments in Implant-Tissue Supported Overdentures: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    F. Alaie

    2010-09-01

    Full Text Available Objective: Retention and resistance of the implant-tissue supported overdenture may be affected by the type of attachment. The aim of this research was to compare the retention and resistance of Nobel Biocare Ball (NBB, Nobel Biocare Bar and Clip (NBBC andSterngold ERA Red (ERAR attachments on an implant-tissue supported overdenture model.Materials and Methods: The attachment samples were divided into 3 groups of NBB,NBBC, and ERAR (5 samples in each group. Two parallel Nobel Biocare Branemark implants were placed symmetrically at the symphysis region of a mandibular test model. A metallic overdenture was fabricated precisely adapted to the model and attached to aZwick testing machine (crosshead speed of 51 mm/min. Dislodging tensile forces were applied in three vertical, oblique, anterior-posterior directions and two situations, at the beginning and after 100 times of insertion/removal of the overdenture, for each sample.The maximum dislodging force was measured. A One-way ANOVA test was employed followed by Tukey’s test.Results: ERAR was the most retentive and resistant in both situations. NBB and NBBC showed the same anterior-posterior resistance at the beginning. All test groups representeda large amount of retention and resistance loss after the insertion/removal of the overdenture,while NBBC showed a higher loss of anterior-posterior resistance than NB.Conclusion: A highest level of retention and resistance was seen in ERAR. The retention and resistance were affected by the wear of attachments.

  6. A novel computer-aided method to fabricate a custom one-piece glass fiber dowel-and-core based on digitized impression and crown preparation data.

    Science.gov (United States)

    Chen, Zhiyu; Li, Ya; Deng, Xuliang; Wang, Xinzhi

    2014-06-01

    Fiber-reinforced composite dowels have been widely used for their superior biomechanical properties; however, their preformed shape cannot fit irregularly shaped root canals. This study aimed to describe a novel computer-aided method to create a custom-made one-piece dowel-and-core based on the digitization of impressions and clinical standard crown preparations. A standard maxillary die stone model containing three prepared teeth each (maxillary lateral incisor, canine, premolar) requiring dowel restorations was made. It was then mounted on an average value articulator with the mandibular stone model to simulate natural occlusion. Impressions for each tooth were obtained using vinylpolysiloxane with a sectional dual-arch tray and digitized with an optical scanner. The dowel-and-core virtual model was created by slicing 3D dowel data from impression digitization with core data selected from a standard crown preparation database of 107 records collected from clinics and digitized. The position of the chosen digital core was manually regulated to coordinate with the adjacent teeth to fulfill the crown restorative requirements. Based on virtual models, one-piece custom dowel-and-cores for three experimental teeth were milled from a glass fiber block with computer-aided manufacturing techniques. Furthermore, two patients were treated to evaluate the practicality of this new method. The one-piece glass fiber dowel-and-core made for experimental teeth fulfilled the clinical requirements for dowel restorations. Moreover, two patients were treated to validate the technique. This novel computer-aided method to create a custom one-piece glass fiber dowel-and-core proved to be practical and efficient. © 2013 by the American College of Prosthodontists.

  7. Mini-implant-supported Molar Distalization

    Directory of Open Access Journals (Sweden)

    Amit Goyal

    2012-01-01

    Full Text Available Temporary anchorage devices popularly called mini-implants or miniscrews are the latest addition to an orthodontist′s armamentarium. The following case report describes the treatment of a 16-year-old girl with a pleasant profile, moderate crowding and Angle′s Class II molar relationship. Maxillary molar distalization was planned and mini-implants were used to preserve the anterior anchorage. After 13 months of treatment, Class I molar and canine relation was achieved bilaterally and there was no anterior proclination. Thus, mini-implants provide a viable option to the clinician to carry out difficult tooth movements without any side effects.

  8. Large-scale laboratory observations of wave forces on a highway bridge superstructure.

    Science.gov (United States)

    2011-10-01

    The experimental setup and data are presented for a laboratory experiment conducted to examine realistic wave forcing on a highway bridge : superstructure. The experiments measure wave conditions along with the resulting forces, pressures, and struct...

  9. Esthetic and Clinical Performance of Implant-Supported All-Ceramic Crowns Made with Prefabricated or CAD/CAM Zirconia Abutments: A Randomized, Multicenter Clinical Trial.

    Science.gov (United States)

    Wittneben, J G; Gavric, J; Belser, U C; Bornstein, M M; Joda, T; Chappuis, V; Sailer, I; Brägger, U

    2017-02-01

    Patients' esthetic expectations are increasing, and the options of the prosthetic pathways are currently evolving. The objective of this randomized multicenter clinical trial was to assess and compare the esthetic outcome and clinical performance of anterior maxillary all-ceramic implant crowns (ICs) based either on prefabricated zirconia abutments veneered with pressed ceramics or on CAD/CAM zirconia abutments veneered with hand buildup technique. The null hypothesis was that there is no statistically significant difference between the 2 groups. Forty implants were inserted in sites 14 to 24 (FDI) in 40 patients in 2 centers, the Universities of Bern and Geneva, Switzerland. After final impression, 20 patients were randomized into group A, restored with a 1-piece screw-retained single crown made of a prefabricated zirconia abutment with pressed ceramic as the veneering material using the cut-back technique, or group B using an individualized CAD/CAM zirconia abutment (CARES abutment; Institut Straumann AG) with a hand buildup technique. At baseline, 6 mo, and 1 y clinical, esthetic and radiographic parameters were assessed. Group A exhibited 1 dropout patient and 1 failure, resulting in a survival rate of 94.7% after 1 y, in comparison to 100% for group B. No other complications occurred. Clinical parameters presented stable and healthy peri-implant soft tissues. Overall, no or only minimal crestal bone changes were observed with a mean DIB (distance from the implant shoulder to the first bone-to-implant contact) of -0.15 mm (group A) and 0.12 mm (group B) at 1 y. There were no significant differences at baseline, 6 mo, and 1 y for DIB values between the 2 groups. Pink esthetic score (PES) and white esthetic score (WES) values at all 3 examinations indicated stability over time for both groups and pleasing esthetic outcomes. Both implant-supported prosthetic pathways represent a valuable treatment option for the restoration of single ICs in the anterior maxilla

  10. Does the number of implants have any relation with peri-implant disease?

    Directory of Open Access Journals (Sweden)

    Bernardo Born PASSONI

    2014-10-01

    Full Text Available Objective: The aim of this study was to evaluate the relationship between the number of pillar implants of implant-supported fixed prostheses and the prevalence of periimplant disease. Material and Methods: Clinical and radiographic data were obtained for the evaluation. The sample consisted of 32 patients with implant-supported fixed prostheses in function for at least one year. A total of 161 implants were evaluated. Two groups were formed according to the number of implants: G1 ≤5 implants and G2 >5 implants. Data collection included modified plaque index (MPi, bleeding on probing (BOP, probing depth (PD, width of keratinized mucosa (KM and radiographic bone loss (BL. Clinical and radiographic data were grouped for each implant in order to conduct the diagnosis of mucositis or peri-implantitis. Results: Clinical parameters were compared between groups using Student’s t test for numeric variables (KM, PD and BL and Mann-Whitney test for categorical variables (MPi and BOP. KM and BL showed statistically significant differences between both groups (p<0.001. Implants from G1 – 19 (20.43% – compared with G2 – 26 (38.24% – showed statistically significant differences regarding the prevalence of peri-implantitis (p=0.0210. Conclusion: It seems that more than 5 implants in total fixed rehabilitations increase bone loss and consequently the prevalence of implants with periimplantitis. Notwithstanding, the number of implants does not have any influence on the prevalence of mucositis.

  11. Implant-supported removable partial dentures in the mandible : A 3-16 year retrospective study

    NARCIS (Netherlands)

    Jensen, Charlotte; Meijer, Henny J A; Raghoebar, Gerry M; Kerdijk, Wouter; Cune, Marco S

    PURPOSE: The purpose of this retrospective study was to assess performance, together with biological and technical complications, of implant-supported removable partial dentures (ISRPD) in mandibular Kennedy class I situations with implants placed in the anterior or posterior position. METHODS: 23

  12. Implant-supported removable partial dentures in the mandible : A 3-16 year retrospective study

    NARCIS (Netherlands)

    Jensen, Charlotte; Meijer, Henny J. A.; Raghoebar, Gerry M.; Kerdijk, Wouter; Cune, Marco S.

    Purpose: The purpose of this retrospective study was to assess performance, together with biological and technical complications, of implant-supported removable partial dentures (ISRPD) in mandibular Kennedy class I situations with implants placed in the anterior or posterior position. Methods: 23

  13. Mastication improvement after partial implant-supported prosthesis use.

    Science.gov (United States)

    Gonçalves, T M S V; Campos, C H; Gonçalves, G M; de Moraes, M; Rodrigues Garcia, R C M

    2013-12-01

    Partially edentulous patients may be rehabilitated by the placement of removable dental prostheses, implant-supported removable dental prostheses, or partial implant fixed dental prostheses. However, it is unclear the impact of each prosthesis type over the masticatory aspects, which represents the objective of this paired clinical trial. Twelve patients sequentially received and used each of these 3 prosthesis types for 2 months, after which maximum bite force was assessed by a strain sensor and food comminution index was determined with the sieving method. Masseter and temporal muscle thicknesses during rest and maximal clenching were also evaluated by ultrasonography. Each maxillary arch received a new complete denture that was used throughout the study. Data were analyzed by analysis of variance for repeated measures, followed by the Tukey test (p mastication, and the magnitude of this effect was related to prosthesis type.

  14. Trauma to an implant-supported crown that was saved by the fixation screw : A case report

    NARCIS (Netherlands)

    den Hartog, Laurens; Meijer, Henny J. A.; Stellingsma, Kees; Santing, Hendrik J.; Raghoebar, Gerry M.

    A traumatic impact to an implant-supported crown might damage the implant, restoration and peri-implant tissues. Ideally, only a small prosthetic retreatment is needed for restoration, as complicated prosthetic retreatments or surgical retreatments in particular, could be very inconvenient for the

  15. Teaching mandibular implant-Supported overdentures in dental schools in North America - a survey.

    Science.gov (United States)

    Ben-Gal, G; Ziv, Y; Weiss, E I; Zabrovsky, A

    2017-05-01

    Mandibular two-implant overdentures are considered the minimum standard of care for edentulous patients and provide an excellent performance, as well as satisfaction to the patients. Dental schools are required to promote the teaching of current treatment options in order to enable students to master state-of-the-art procedures. The purpose of this study was to examine how the theoretical and practical aspects of mandibular two-implant overdentures are taught in dental schools in North America. Data were collected via an online questionnaire that included questions regarding the theoretical and clinical courses, surgical procedure and imaging method. Of 75 schools, 36 responded to the survey. Almost all the schools teach the subject theoretically, but it is not mandatory for students to perform in most of the schools. Only a minority (23%) of the mandibular dentures made by students are implant-supported. Almost all of the schools (94%) use two implants to support overdentures, and Locator abutment is used almost exclusively. The prevalent imaging for the surgical procedure is CT scans, although 30% of the schools use panoramic radiograph. None of the schools loads the implants immediately after surgery. Some clear trends are apparent in the current survey: the use of two implants, no use of bar connectors and delayed loading of the implants. It is likely that graduates will not have sufficient clinical skills and will need continuing education to be familiar with the required procedures, both surgical and prosthetic. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. A new one-step procedure for pulmonary valve implantation of the melody valve: Simultaneous prestenting and valve implantation.

    Science.gov (United States)

    Boudjemline, Younes

    2018-01-01

    To describe a new modification, the one-step procedure, that allows interventionists to pre-stent and implant a Melody valve simultaneously. Percutaneous pulmonary valve implantation (PPVI) is the standard of care for managing patients with dysfunctional right ventricular outflow tract, and the approach is standardized. Patients undergoing PPVI using the one-step procedure were identified in our database. Procedural data and radiation exposure were compared to those in a matched group of patients who underwent PPVI using the conventional two-step procedure. Between January 2016 and January 2017, PPVI was performed in 27 patients (median age/range, 19.1/10-55 years) using the one-step procedure involving manual crimping of one to three bare metal stents over the Melody valve. The stent and Melody valve were delivered successfully using the Ensemble delivery system. No complications occurred. All patients had excellent hemodynamic results (median/range post-PPVI right ventricular to pulmonary artery gradient, 9/0-20 mmHg). Valve function was excellent. Median procedural and fluoroscopic times were 56 and 10.2 min, respectively, which significantly differed from those of the two-step procedure group. Similarly, the dose area product (DAP), and radiation time were statistically lower in the one-step group than in the two-step group (P step procedure is a safe modification that allows interventionists to prestent and implants the Melody valve simultaneously. It significantly reduces procedural and fluoroscopic times, and radiation exposure. © 2017 Wiley Periodicals, Inc.

  17. Maxillary implant-supported overdentures opposed by (partial) natural dentitions : A 5-year prospective case series study

    NARCIS (Netherlands)

    Boven, G. C.; Slot, J. W. A.; Raghoebar, G. M.; Vissink, A.; Meijer, H. J. A.

    2017-01-01

    The aim of this study was to assess the 5-year treatment outcome of maxillary implant-retained overdentures opposed by natural antagonistic teeth. Fifty consecutive patients received maxillary overdentures supported by six dental implants. Implants were placed in the anterior region, if enough bone

  18. Simultaneous communication supports learning in noise by cochlear implant users

    NARCIS (Netherlands)

    Blom, H.C.; Marschark, M.; Machmer, E.

    2017-01-01

    Objectives: This study sought to evaluate the potential of using spoken language and signing together (simultaneous communication, SimCom, sign-supported speech) as a means of improving speech recognition, comprehension, and learning by cochlear implant (CI) users in noisy contexts.Methods: Forty

  19. One-step breast reconstruction with polyurethane-covered implants after skin-sparing mastectomy.

    Science.gov (United States)

    Rancati, Alberto; Soderini, Alejandro; Dorr, Julio; Gercovich, Gustavo; Tessari, Luciano; Gonzalez, Eduardo

    2013-12-01

    Skin-sparing mastectomy (SSM) and immediate one-step breast reconstruction with implants has become an increasingly popular, effective treatment for selected patients with breast carcinoma. However, it is associated with high complication rates. Breast augmentation with polyurethane-covered implants (PCIs) has consistently had optimal short-term and long-term results with low rates of capsular contracture. The aim of this study was to evaluate the clinical and aesthetic outcomes of immediate one-step breast reconstruction with PCI after SSM in early breast cancer patients at a single institution. We reviewed the records of 221 consecutive breast cancer patients who underwent one-stage immediate reconstruction with PCI after SSM from 1995 through 2005. Patient and tumour characteristics, type of reconstruction, postoperative complications, aesthetic results and recurrence rate were analysed. The mean age of the patients was 52±11 years (range, 30-76; standard deviation (SD), 11). The American Joint Committee on Cancer (AJCC) pathologic stages were 0 (10%), I (63.3%) and II (26.7%). Thirty-nine (17.65%; confidence interval (CI)=13.04-23.1) of the 221 patients had complications; seven had prosthesis extrusion requiring an implant (five due to skin necrosis, one due to infection and one due to late haematoma). In six of these seven cases, the procedure was indicated for local recurrence after conservative breast surgery with adjunctive radiation therapy (rescue procedure). Thirty-two (14.4%) patients had minor complications: 12 had cutaneous rash, four had malpositioned implants and 16 had inadequate implant projection. At long-term follow-up, four (1.8%) patients had developed grade IV capsular contracture associated with postoperative radiation therapy. At a median follow-up of 98 months (range, 36-156), 14 (6.3%) patients had tumour recurrence and 12.2% had distant metastasis. Nineteen patients had died of cancer, and 192 (86.8%) remained disease free. One

  20. New 3D technologies applied to assess the long-term clinical effects of misfit of the full jaw fixed prosthesis on dental implants.

    Science.gov (United States)

    Jokstad, Asbjørn; Shokati, Babak

    2015-10-01

    To assess implant:suprastructure misfit in patients with an edentulous jaw restored by an implant-retained fixed dental prosthesis (FDP) and its association with biologic and mechanical adverse events over an extensive period. Thirty patients with an edentulous mandible treated with implant-supported prosthetics before 2000 were examined clinically in 2012. Each patient had received 4 to 6 implants to retain a FDP made from acrylic and three different metal alloys, that is, Ag-Pd, Pd-Ag, and Au type IV. The implant intra-oral locations were recorded digitally by use of an intra-oral scanner, and the intaglio surface of the detached FDP was recorded using a desktop scanner. The fit was estimated by digital matching of the STL files using industrial metrological software. The average misfit was correlated with the average marginal bone loss and the prevalence of screw loosening or fractures, using the patient as the statistical unit. Over an average of 19 years (range 12 to 32), 5 implants had been lost in 4 participants (96.7% implant survival) and 8 eight prostheses (26.7%) had been remade. Anaverage misfit was 150 μm (SD 35, range 95-232, CI 138-163). An average marginal bone loss of 2.2 mm (SD = 0.7) had occurred (range 0.6 to 5.8 mm) for individual implants. The correlation between framework misfit and marginal bone loss was weak (R² = 0.04) (P = 0.29). The prostheses with a history of screw-related adverse events showed average misfit of 169 μm (SD = 32) vs. those with no history of screw-related adverse events, that is, 134 μm (SD = 30) (P = 0.005, Student's t-test). Fourteen of the 30 participants had experienced at least one incidence of screw loosening or fracture of prosthetic or abutment screw(s) over the period of follow-up. The occurrence among the frameworks fabricated with different metal alloys did not differ (P > 0.05, Fisher's exact test). Combining STL files with best-fit algorithms to appraise misfit is feasible using

  1. Implant-supported removable partial dentures in the mandible: A 3-16 year retrospective study.

    Science.gov (United States)

    Jensen, Charlotte; Meijer, Henny J A; Raghoebar, Gerry M; Kerdijk, Wouter; Cune, Marco S

    2017-04-01

    The purpose of this retrospective study was to assess performance, together with biological and technical complications, of implant-supported removable partial dentures (ISRPD) in mandibular Kennedy class I situations with implants placed in the anterior or posterior position. 23 subjects with two endosseous implants to support a bilateral-free-ending mandibular removable denture were examined. Eight subjects had implants in the premolar (anterior) region and 15 subjects implants in the molar (posterior) region. Biological and technical complications were recorded from the patients' medical record. Patients filled out a validated questionnaire regarding their appreciation of oral health related quality of life (OHIP-NL49) and a VAS score on overall satisfaction. Over a mean follow-up period of 8 years (median 8 years, range 3-16 years) the cumulative implant survival rate was 91.7% (SE 0.05). Mean peri-implant bone loss was 0.9mm (SD 1.0mm). Scores for bleeding on probing, plaque and mucosal health were generally low, but significantly worse for posteriorly placed implants. Significantly more biological complications occurred in the posterior group (X 2 (1)=3.9; p=0.048). In 65% of the cases no technical complications were registered. Mean overall OHIP score was 16.1 (SD 18.4) and patients were highly satisfied (VAS: 8.4; SD 2.1). Within the limitations of this retrospective study, in case of a Kennedy class I situation in the mandible, an ISRPD is a viable treatment option with a high implant survival rate and satisfied patients after a maximum of 16 years. Technical and biological complications should be anticipated. Anteriorly placed implants performed slightly better. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  2. Superstructure formation in PrNi_2Al_3 and ErPd_2Al_3

    International Nuclear Information System (INIS)

    Eustermann, Fabian; Hoffmann, Rolf-Dieter; Janka, Oliver; Oldenburg Univ.

    2017-01-01

    The intermetallic phase ErPd_2Al_3 was obtained by arc-melting of the elements and subsequent annealing for crystal growth. The sample was studied by X-ray diffraction on powders and single crystals. The structure of ErPd_2Al_3 was refined from X-ray diffraction data and revealed a superstructure of PrNi_2Al_3 - a CaCu_5 derivative (P6/m, a=1414.3(1), c=418.87(3) pm wR=0.0820, 1060 F"2 values, 48 variables). The same superstructure was subsequently found for PrNi_2Al_3 (P6/m, a=1407.87(4), c=406.19(2) pm, wR=0.0499, 904 F"2 values, 47 variables). In the crystal structure, the aluminium and transition metal atoms form a polyanionic network according to [T_2Al_3]"δ"-, while rare earth atoms fill cavities within the networks. They are coordinated by six transition metal and twelve aluminum atoms. In contrast to the PrNi_2Al_3 type structure reported so far, two crystallographic independent rare-earth sites are found of which one (1b) is shifted by 1/2 z, causing a distortion in the structure along with a recoloring of the T and Al atoms in the network.

  3. Experimental Study of Properties of Pervious Concrete used for Bridge Superstructure

    DEFF Research Database (Denmark)

    Lund, Mia Schou Møller; Hansen, Kurt Kielsgaard; Hertz, Kristian Dahl

    2014-01-01

    around freezing point are exposed to a harsh freeze-thaw impact, since bridges are not only cooled from the topside, as a normal road bed, but also from underneath. Hence, the demands to the moisture properties of the superstructure are strict in order to ensure the necessary durability. Pearl...

  4. Globalisation in Africa: Reflecting on Peter Jarvis's Superstructure and Substructure Model

    Science.gov (United States)

    Preece, Julia

    2017-01-01

    This paper reflects on Peter Jarvis' book "Globalisation, lifelong learning and the learning society," volume 2--in which he describes human learning within a global context and factors contributing to globalisation. He describes the relationship of power between countries manifested as the superstructure and sub structure. The paper…

  5. Implant-Supported PMMA Monolithic Full-Arch Rehabilitation with Surgical Computer-Planned Guide and Immediate Provisional: A Case Report with One Year Follow-Up

    Directory of Open Access Journals (Sweden)

    Vincenzo Luca Zizzari

    2018-01-01

    Full Text Available The aim of this case report is to describe the surgical and prosthetic procedures to achieve maxillary and mandibular implant-supported PMMA monolithic full-arch rehabilitation (PMFR with surgical computer-planned guide and immediate provisional. In such cases, the correct planning of dental implants’ position, length, and diameter and the prosthetic phases via computer-aided design are very important to achieve good aesthetic and functional long-lasting results.

  6. Implant-Supported PMMA Monolithic Full-Arch Rehabilitation with Surgical Computer-Planned Guide and Immediate Provisional: A Case Report with One Year Follow-Up

    OpenAIRE

    Zizzari, Vincenzo Luca; Tacconelli, Gianmarco

    2018-01-01

    The aim of this case report is to describe the surgical and prosthetic procedures to achieve maxillary and mandibular implant-supported PMMA monolithic full-arch rehabilitation (PMFR) with surgical computer-planned guide and immediate provisional. In such cases, the correct planning of dental implants’ position, length, and diameter and the prosthetic phases via computer-aided design are very important to achieve good aesthetic and functional long-lasting results.

  7. Laws of phase formation in ion-implanted metals

    International Nuclear Information System (INIS)

    Kazdaev, H.R.; Abylkhalykova, R.B.; Skakov, M.K.

    2004-01-01

    Full text: Main laws of ordered structures formation at molybdenum implantation by elements forming phases of introduction (B, C, N, 0, Si, P, S) are discovered in this work. According to them the character of structural and phase transformations in molybdenum at ion implantation is determined not by kinetic parameters of bombarding particles and their chemical activity but by size factor η x/Me (ratio of nuclear radii of introduced elements and atoms of a matrix). At change of its meaning in the certain limits the following can be observed: superstructures formation (η x/Mo x/Mo x/Mo >0.69). In the latter case at the further implantation doze increasing recrystallization of molybdenum monocrystalline layers amorphized during previous bombarding with chemical connection formation takes place, characterized by us as ion-inducted synthesis. The phenomenon discovered on the samples implanted by phosphorus ions. As the result, the high-temperature phase of molybdenum monophosphide MoP having densely situated lattice was synthesized. The complete confirmation of the main laws of structural and phased transformations at ion implantation established by results on molybdenum monocrystals with OCC lattice was achieved at realization of similar researches on the other transitive metal - zirconium which differs from molybdenum according to a number of attributes: a type of an initial lattice structural condition (large scaled polycrystal), presence of interparticle borders and high solubility of atmospheric impurities (nitrogen, carbon, oxygen). The discovered laws have proved to be true also according to ion implanted samples of monocrystal tungsten and polycrystal tantalum

  8. Zirconia- versus metal-based, implant-supported abutments and crowns

    DEFF Research Database (Denmark)

    Hosseini, Mandana

    , the selection of restoration materials should be based on proper optical characteristics in addition to biocompatibility and sufficient strength of materials. Abutments and crowns based on zirconia are one of the most recent alternatives to metal abutments and metal-ceramic crowns. To date, only few comparative...... and to estimate long-term biomechanical results of zirconia-based versus metal-based restorations. The aim of study I was to analyse the mode of fracture and number of cyclic loadings until veneering fracture of zirconia-based all-ceramic restorations compared to metal-ceramic restorations. The aim of study II...... was to test the reliability and validity of six aesthetic parameters used at the Copenhagen Dental School to assess the aesthetic outcome of implant-supported restorations. The aims of study III and IV were to compare the influence of different abutment and crown materials on biological, biomechanical...

  9. Simultaneous communication supports learning in noise by cochlear implant users.

    Science.gov (United States)

    Blom, Helen; Marschark, Marc; Machmer, Elizabeth

    2017-01-01

    This study sought to evaluate the potential of using spoken language and signing together (simultaneous communication, SimCom, sign-supported speech) as a means of improving speech recognition, comprehension, and learning by cochlear implant (CI) users in noisy contexts. Forty eight college students who were active CI users, watched videos of three short presentations, the text versions of which were standardized at the 8 th -grade reading level. One passage was presented in spoken language only, one was presented in spoken language with multi-talker babble background noise, and one was presented via simultaneous communication with the same background noise. Following each passage, participants responded to 10 (standardized) open-ended questions designed to assess comprehension. Indicators of participants' spoken language and sign language skills were obtained via self-reports and objective assessments. When spoken materials were accompanied by signs, scores were significantly higher than when materials were spoken in noise without signs. Participants' receptive spoken language skills significantly predicted scores in all three conditions; neither their receptive sign skills nor age of implantation predicted performance. Students who are CI users typically rely solely on spoken language in the classroom. The present results, however, suggest that there are potential benefits of simultaneous communication for such learners in noisy settings. For those CI users who know sign language, the redundancy of speech and signs potentially can offset the reduced fidelity of spoken language in noise. Accompanying spoken language with signs can benefit learners who are CI users in noisy situations such as classroom settings. Factors associated with such benefits, such as receptive skills in signed and spoken modalities, classroom acoustics, and material difficulty need to be empirically examined.

  10. [Intraocular lens implantation with one loop haptic amputated: a new propose to the subluxation lens surgical treatment].

    Science.gov (United States)

    Ventura, Marcelo; Endriss, Daniela

    2010-01-01

    To evaluate the postoperative results of congenital lens subluxation corrected by a new technique. Retrospective chart review of 21 eyes of 13 patients with no traumatic lens subluxation who underwent surgery in Altino Ventura Foundation from April, 1999 to April, 2004. The mean age was 8.7 +/- 5.4 years old, and the mean follow-up period was 21.5 +/- 19.3 months. Patients underwent phacoaspiration, endocapsular ring and intraocular lens (IOL) implantation. The implanted IOL had one loop haptic excised and was supported above the ring, inside the capsular bag promoting intraocular lens centralization. Visual acuity improvement was observed in all cases. There was a significant reduction of the spherical equivalent and spherical component comparing the pre and postoperative refraction (psubluxation surgical treatment, promoting lens centralization and postoperative visual acuity improvement.

  11. Comparison of fixed implant-supported prostheses, removable implant-supported prostheses, and complete dentures: patient satisfaction and oral health-related quality of life.

    Science.gov (United States)

    Oh, Sung-Hee; Kim, Younhee; Park, Joo-Yeon; Jung, Yea Ji; Kim, Seong-Kyun; Park, Sun-Young

    2016-02-01

    The purpose of this study was to compare patient satisfaction and oral health-related quality of life (OHRQoL) among fully edentulous patients treated with either fixed implant-supported prostheses (FP), removable implant-supported prostheses (RP), or complete dentures (CD). Eighty-six patients - 29 FP, 27 RP, and 30 CD patients - participated in this study. The survey was conducted using face-to-face interviews with a questionnaire that included a patient satisfaction scale and Oral Health Impact Profile (OHIP-14). We measured patient satisfaction after prosthetic treatments and OHRQoL before and after the treatments. After prosthetic treatments, OHRQoL increased in all three groups (P patient satisfaction and OHRQoL, and both groups showed greater improvement compared with the CD group. Specifically, the OHRQoL dimensions of functional limitation, physical pain, psychological discomfort, and psychological disability in the FP group, and functional limitation in the RP group, improved greatly in comparison with the CD group (P patient satisfaction than the CD treatment. Reliable information of OHRQoL and patient satisfaction helps experts and patients choose the best prosthetic treatment option. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Simultaneous measurement of temperature and tensile loading using superstructure FBGs developed by laser direct writing of periodic on-fiber metallic films

    International Nuclear Information System (INIS)

    Alemohammad, Hamidreza; Toyserkani, Ehsan

    2009-01-01

    This paper addresses the development of superstructure fiber Bragg gratings (FBGs) by laser-assisted direct writing of on-fiber metallic films. A novel laser direct write method is characterized to fabricate periodic films of silver nanoparticles on the non-planar surface of as-fabricated FBGs. Silver films with a thickness of 9 µm are fabricated around a Bragg grating optical fiber. The performance of the superstructure FBG is studied by applying temperature and tensile stress on the fiber. An opto-mechanical model is also developed to predict the optical response of the synthesized superstructure FBG under thermal and structural loadings. The results show that the reflectivity of sidebands in the reflection spectrum can be tuned up to 20% and 37% under thermal and structural loadings, respectively. In addition, the developed superstructure FBG is used for simultaneous measurement of force and temperature to eliminate the inherent limitation of regular FBGs in multi-parameter sensing

  13. A novel high-temperature commensurate superstructure in a natural bariopyrochlore: A structural study by means of a multiphase crystal structure refinement

    International Nuclear Information System (INIS)

    Bindi, L.; Petricek, V.; Withers, R.L.; Zoppi, M.; Bonazzi, P.

    2006-01-01

    Additional X-ray diffraction effects yielding an eightfold commensurate superstructure [a=20.974(5)A] of the ideal pyrochlore structure were observed after annealing at 873K of a thallium-doped bariopyrochlore single crystal. Electron diffraction indicated the coexistence of two cubic phases, the pyrochlore structure and a new F-centred, cubic phase. The superstructure was solved and refined in the space group F4-bar 3m. The two phases were combined together and refined as independently diffracting to R=0.0628. The resulting unit-cell content is (A,-bar ) 20 Nb 16 Ti 2 O 53 (Z=8), with A=Ba, Tl, Ce, Th. For some atomic positions of the superstructure, third- and fourth-order anharmonic ADP's were used to account for the specific density shape having a continuous character as typical for ionic conductors. There are three distinct clusters in the superstructure, leading to a new structure type no longer strictly of pyrochlore-structure type

  14. Evaluation of stress distribution characteristics on various bar designs of three-implant-supported mandibular overdentures

    Directory of Open Access Journals (Sweden)

    Emre Tokar

    2017-01-01

    Full Text Available Objective: Implant-supported-overdentures, instead of conventional complete dentures, are frequently recommended to rehabilitate patients having edentulous mandible. The aim of this study was to evaluate the stress distribution characteristics of mandibular implant-supported overdentures with four different bar attachment designs. Materials and Method: A photoelastic mandibular model with three implants (3.75 mm - 13 mm placed at the interforaminal region was generated from a cast of an edentulous mandible. Four mandibular bar overdenture designs were fabricated: bar-clip, bar-galvano, bar-locator, and bar-ceka. Axial vertical loads (135 N were applied to the central fossa of the right first molar area for each overdenture design. Stress concentrations were recorded photographically and analyzed visually. Results: The tested bar attachment designs revealed low and moderate stress levels. The lowest stress was observed with the bar-clip design, followed by bar-locator, bar-ceka, and bar-galvano designs. Conclusion: The loads were distributed to all of the implants. Studied designs experienced moderate stress levels around the loaded side implant. Bars with distally placed stud attachments and surface treatment with electroforming seems to increase stress levels around the implants.

  15. The effect of flexible acrylic resin on masticatory muscle activity in implant-supported mandibular overdentures: a controlled clinical trial

    OpenAIRE

    Ibraheem, Eman Mostafa Ahmed; Nassani, Mohammad Zakaria

    2016-01-01

    Background It is not yet clear from the current literature to what extent masticatory muscle activity is affected by the use of flexible acrylic resin in the construction of implant-supported mandibular overdentures. Objective To compare masticatory muscle activity between patients who were provided with implant-supported mandibular overdentures constructed from flexible acrylic resin and those who were provided with implant-supported mandibular overdentures constructed from heat-cured conven...

  16. Maxillary overdentures supported by anteriorly or posteriorly placed implants opposed by a natural dentition in the mandible: a 1-year prospective case series study.

    Science.gov (United States)

    Slot, Wim; Raghoebar, Gerry M; Vissink, Arjan; Meijer, Henny J A

    2014-02-01

    For maxillary overdenture therapy, treatment guidelines are missing. There is a need for longitudinal studies. The purpose of this 1-year prospective case series study was to assess the treatment outcome of maxillary overdentures supported by six dental implants opposed by natural antagonistic teeth in the mandible. Fifty patients were treated with a maxillary overdenture supported by six dental implants, either placed in the anterior region (n = 25 patients) or in the posterior region (n = 25 patients). Items of evaluation were the following: survival of implants, condition of hard and soft peri-implant tissues, and patients' satisfaction. One-year implant survival rate was 98% in the anterior group and 99.3% in the posterior group. Mean radiographic bone loss in the anterior and posterior groups after 1 year of loading was 0.22 and 0.50 mm, respectively. Mean scores for plaque, calculus, gingiva, bleeding, and pocket probing depth were low, and patients' satisfaction was high, with no differences between the groups. Six dental implants placed in either the anterior region or the posterior region of the edentulous maxilla, connected with a bar, and opposed by antagonistic teeth in the mandible supply a proper base for the support of an overdenture. © 2012 Wiley Periodicals, Inc.

  17. Overcoming artificial spatial correlations in simulations of superstructure domain growth with parallel Monte Carlo algorithms

    International Nuclear Information System (INIS)

    Schleier, W.; Besold, G.; Heinz, K.

    1992-01-01

    The authors study the applicability of parallelized/vectorized Monte Carlo (MC) algorithms to the simulation of domain growth in two-dimensional lattice gas models undergoing an ordering process after a rapid quench below an order-disorder transition temperature. As examples they consider models with 2 x 1 and c(2 x 2) equilibrium superstructures on the square and rectangular lattices, respectively. They also study the case of phase separation ('1 x 1' islands) on the square lattice. A generalized parallel checkerboard algorithm for Kawasaki dynamics is shown to give rise to artificial spatial correlations in all three models. However, only if superstructure domains evolve do these correlations modify the kinetics by influencing the nucleation process and result in a reduced growth exponent compared to the value from the conventional heat bath algorithm with random single-site updates. In order to overcome these artificial modifications, two MC algorithms with a reduced degree of parallelism ('hybrid' and 'mask' algorithms, respectively) are presented and applied. As the results indicate, these algorithms are suitable for the simulation of superstructure domain growth on parallel/vector computers. 60 refs., 10 figs., 1 tab

  18. Influences of microgap and micromotion of implant-abutment interface on marginal bone loss around implant neck.

    Science.gov (United States)

    Liu, Yang; Wang, Jiawei

    2017-11-01

    To review the influences and clinical implications of micro-gap and micro-motion of implant-abutment interface on marginal bone loss around the neck of implant. Literatures were searched based on the following Keywords: implant-abutment interface/implant-abutment connection/implant-abutment conjunction, microgap, micromotion/micromovement, microleakage, and current control methods available. The papers were then screened through titles, abstracts, and full texts. A total of 83 studies were included in the literature review. Two-piece implant systems are widely used in clinics. However, the production error and masticatory load result in the presence of microgap and micromotion between the implant and the abutment, which directly or indirectly causes microleakage and mechanical damage. Consequently, the degrees of microgap and micromotion further increase, and marginal bone absorption finally occurs. We summarize the influences of microgap and micromotion at the implant-abutment interface on marginal bone loss around the neck of the implant. We also recommend some feasible methods to reduce their effect. Clinicians and patients should pay more attention to the mechanisms as well as the control methods of microgap and micromotion. To reduce the corresponding detriment to the implant marginal bone, suitable Morse taper or hybrid connection implants and platform switching abutments should be selected, as well as other potential methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Implant Supported Distal Extension over Denture Retained by Two Types of Attachments. A Comparative Radiographic Study by Cone Beam Computed Tomography

    Science.gov (United States)

    Mahrous, Ahmed I; Aldawash, Hussien A; Soliman, Tarek A; Banasr, Fahad H; Abdelwahed, Ahmed

    2015-01-01

    Background: This study was conducted to compare and evaluate the effect of two different attachments (locator attachment and ball and socket [B&S] attachment) on implants and natural abutments supporting structures, in cases of limited inter-arch spaces in mandibular Kennedy Class I implant supported removable partial over dentures by measuring the bone height changes through the cone beam radiographic technology. Materials and Methods: Two implants were positioned in the first or second molar area following the two-stage surgical protocol. Two equal groups were divided ten for each: Group I: Sides were the placed implants restored by the locator attachment. Group II: The other sides, implants were restored by B&S attachment. Evaluation of the implants and main abutments supporting structures of each group was done at the time of removable partial over denture insertion, 6, 12 and 18 months by measuring the bone height changes using cone beam computed tomography. Results: Implants with locator attachment showed marginal bone height better effects on implants and main abutments supporting structures. Conclusion: Implants restored by locator attachment shows better effects on bone of both main natural abutments and implant than those restored with ball and socket. PMID:26028894

  20. Influence of restorative materials on color of implant-supported single crowns in esthetic zone: A spectrophotometric evaluation

    DEFF Research Database (Denmark)

    M., Peng; W.-J., Zhao; M., Hosseini

    2017-01-01

    of the esthetic outcome of soft tissue around implant-supported single crowns in the anterior zone, and the crown color match score was used for subjective evaluation of the esthetic outcome of implant-supported restoration. ANOVA analysis was used to compare the differences among groups and Spearman correlation...

  1. The Origin of the Superstructure in Bi2Sr2CaCu2O8+dgr as Revealed by Scanning Tunneling Microscopy.

    Science.gov (United States)

    Kirk, M D; Nogami, J; Baski, A A; Mitzi, D B; Kapitulnik, A; Geballe, T H; Quate, C F

    1988-12-23

    Real-space images with atomic resolution of the BiO plane of Bi(2)Sr(2)CaCu(2)O(8+delta) were obtained with a scanning tunneling microscope. Single-crystal samples were cleaved and imaged under ultrahigh vacuum conditions at room temperature. The images clearly show the one-dimensional incommensurate superstructure along the b-axis that is common to this phase. High-resolution images show the position of the Bi atoms, revealing the structural nature of the superlattice. A missing row of Bi atoms occurs either every nine or ten atomic sites in both (110) directions, accounting for the measured incommensurate periodicity of the superstructure. A model is proposed that includes missing rows of atoms, as well as displacements of the atomic positions along both the a- and c-axis directions.

  2. The origin of the superstructure in Bi2Sr2CaCu2O(8+delta) as revealed by scanning tunneling microscopy

    Science.gov (United States)

    Kirk, M. D.; Nogami, J.; Baski, A. A.; Mitzi, D. B.; Kapitulnik, A.

    1988-12-01

    Real-space images with atomic resolution of the BiO plane of Bi2Sr2CaCu2O(8+delta) were obtained with a scanning tunneling microscope. Single-crystal samples were cleaved and imaged under ultrahigh vacuum conditions at room temperature. The images clearly show the one-dimensional incommensurate superstructure along the b-axis that is common to this phase. High-resolution images show the position of the Bi atoms, revelaing the structural nature of the superlattice. A missing row of Bi atoms occurs either every nine or ten atomic sites in both 110-line directions, accounting for the measured incommensurate periodicity of the superstructure. A model is proposed that includes missing rows of atoms, as well as displacements of the atomic positions along both the a- and c-axis directions.

  3. Clinical Parameters and Crestal Bone Loss in Internal Versus External Hex Implants at One Year after Loading

    Directory of Open Access Journals (Sweden)

    HamidReza Arab

    2015-09-01

    Full Text Available Introduction: The survival of an implant system is affected by the choice of antirotational design, which can include an external or internal hex. Implant success also is affected by the maintenance of the crestal bone around implants. The aim of present study was to evaluate the crestal bone loss and clinical parameters related to bone loss in patients loaded with an external or internal hex 3i implant (3i Implant Innovation, Palm Beach Gardens, FL, USA. The evaluations were performed one year after loading. Materials and Methods: A total of 39 implants (23 external hex, 16 internal hex were placed randomly in 23 patients (10 male, 13 female by a submerged approach. None of patients had compromised conditions or parafunctional habits. At placement and at one year after loading, periapical radiographs were taken via the parallel method from the implant sites. Results: Crestal bone loss was -0.712±0.831 mm in implants with an internal hex connection and -0.139±0.505 mm in implants with an external hex connection (P≤0.05. No correlation was found between crestal bone loss and parameters such as age, gender, jaw, implant location (anterior, premolar, or molar, implant diameter, or implant length. Conclusions: Crestal bone loss was greater in patients with internal hex 3i implants than in those with external implants. Similar results in other clinical factors were found between the groups.

  4. Prediction of hardness in pieces of quenched and tempered steel

    International Nuclear Information System (INIS)

    Yanzon, Rodolfo Carlos; Rodriguez, Augusto; Sanchez, Arlington Ricardo

    2006-01-01

    This presentation describes the first stage of a work plan to obtain a simple software, for predicting properties at certain points of a quenched and tempered piece. In this first stage, this prediction is limited to cylindrical pieces made with steels whose chemical composition is within a certain range. The methodology basically consists of obtaining , from experimental data, a mathematical tool able to predict the hardness value, for Jominy test piece ends made with this type of steel. This meant beginning with the analysis of the usual forms of theoretical calculation of Jominy curves of quenched samples, which resulted in a proposal to modify the Just equation. Two different mathematical methods were then developed, that could predict hardness values in tempered Jominy test pieces. One, based on the determination of polynomic equations, that reproduces the loss of hardness at points along the test piece, base on the quenching value and as a function of the tempering temperature. The other one, which uses the lineal multidimensional interpolation method, because of its ease of application, has been selected as the mathematical tool to use in the software under development. At this stage of the work, the relationship between the points on the piece and those on the Jominy test pieces is carried out by the Lamont method and the representative variable of the temperature/time combination for the tempering process itself, is obtained with software based on the Hollomon and Jaffe expression. Data is needed to define: a) chemical composition and grain size of the steel used, b) diameter of the piece, c) 'H G ' severity of the quenching medium d) temperature and time of the tempering. The work's second stage continued with the addition of hardness values measured in Jominy test pieces made with other steels. The chemical composition and grain size data of each steel introduced are converted by the software into one more variable, using the concept of ideal critical

  5. Retentiveness of implant-supported metal copings using different luting agents

    Directory of Open Access Journals (Sweden)

    Farahnaz Nejatidanesh

    2012-01-01

    Full Text Available Background: With regard to potential retrievability of cement-retained implant restorations, the retentive strength of the luting agents is critical. The aim of this study was to evaluate the retention values of implant-supported metal copings using different luting agents. Materials and Methods: Twenty ITI implant analogs and solid abutments of 5.5-mm height were embedded vertically in autopolymerizing acrylic resin blocks. Metal copings with a loop on the occlusal surface were fabricated using base metal alloy (Rexillium III. The copings were luted using eight cements with different retention mechanisms (Panavia F2.0, Fuji Plus, Fleck′s, Poly F, Fuji I, Temp Bond, GC-free eugenol, and TempSpan under static load of 5 kg (n=10. All specimens were incubated at 37°C for 24 hours, conditioned in artificial saliva for 7 days and thermocycled for 5000 cycles (5-55°C. The dislodging force was measured using a universal testing machine at a crosshead speed of 5 mm/min. Statistical analyses were performed using Kruskal-Wallis (α=0.05 and Mann-Whitney tests with Bonferroni correction (α=0.001. Results: Fuji Plus and TempSpan had the highest and the least mean retentive strength, respectively (320.97±161.47, 3.39±2.33. There was no significant difference between Fuji Plus, Fleck′s, Ploy F, and Panavia F2.0. These cements were superior to provisional cements and Fuji I (P<0.001 which showed statistically same retentive strength. Conclusion: Within the conditions of this study, the resin modified glass ionomer, zinc phosphate, zinc polycarboxylate, and Panavia F2.0 had statistically the same retentive quality and are recommended for definitive cementation of single implant-supported restorations. The provisional cements and glass ionomer may allow retrievability of these restorations.

  6. The success rate of narrow body implants used for supporting immediate provisional restorations: a pilot feasibility study.

    Science.gov (United States)

    Wang, Hom-Lay; Okayasu, Kozue; Fu, Jia-Hui; Hamerink, Howard A; Layher, Mary G; Rudek, Ivan Elimar

    2012-12-01

    Implants were first designed to be used in the reconstruction of edentulous mandibles. However, with the technological advancement, enormous changes were made to improve the implant design and surface characteristics leading to the wide use of implants in the replacement of missing teeth. During the transition from an edentulous span to a fixed prosthesis, narrow body implants (NBIs) have been proposed to enhance patient comfort and function. Therefore, this study was aimed at investigating the survival and success rates of NBIs used for supporting immediately nonfunctional loaded provisional fixed partial denture (PFPD). Either 2.2- or 2.4-mm-diameter dental implants were placed transmucosally into the edentulous ridges of 10 partially edentulous patients. PFPD of self-cured bis-acryl composite material were made using either a vacuform template chairside or a relined prefabricated PFPD. Occlusal adjustments were made to ensure that there was no functional loading on the provisional restorations before they were secured onto the transitional implants. At 1 year, the implant success and survival rates were 38.7% and 93.5%, respectively, with a mean percentage of bone loss of 9.46% (0%-40%) and a mean bone loss of 1.19 mm (range: 0-3.5 mm). With a favorable implant survival rate, the use of NBIs to support provisional restorations seemed to be a feasible treatment option. In addition, there is merit for research on the long-term use of NBIs-supported final prostheses.

  7. Effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts.

    Science.gov (United States)

    Ebadian, Behnaz; Rismanchian, Mansor; Dastgheib, Badrosadat; Bajoghli, Farshad

    2015-01-01

    Different factors such as impression techniques and materials can affect the passive fit between the superstructure and implant. The aim of this study was to determine the effect of different impression materials and techniques on the dimensional accuracy of implant definitive casts. Four internal hex implants (Biohorizons Ø4 mm) were placed on a metal maxillary model perpendicular to the horizontal plane in maxillary lateral incisors, right canine and left first premolar areas. Three impression techniques including open tray, closed tray using ball top screw abutments and closed tray using short impression copings and two impression materials (polyether and polyvinyl siloxane) were evaluated (n = 60). The changes in distances between implant analogues in mediolateral (x) and anteroposterior (y) directions and analogue angles in x/z and y/z directions in the horizontal plane on the definitive casts were measured by coordinate measuring machine. The data were analyzed by multivariate two-way analysis of variance and one sample t-test (α = 0.05). No statistical significant differences were observed between different impression techniques and materials. However, deviation and distortion of definitive casts had a significant difference with the master model when short impression copings and polyvinyl siloxane impression material were used (P impression materials (P impression techniques; however, less distortion and deviation were observed in the open tray technique. In the closed tray impression technique, ball top screw was more accurate than short impression copings.

  8. Giant reversible magnetocaloric effect in flower-like β-Co(OH){sub 2} hierarchical superstructures self-assembled by nanosheets

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xianguo; Feng, Chao; Xiao, Feng; Jin, Chuangui; Xia, Ailin, E-mail: liuxianguohugh@gmail.com, E-mail: eeswor@polyu.edu.hk [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Ma' anshan, PR (China); Or, Siu Wing [Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Sun, Yuping [Center for Engineering Practice and Innovation Education, Anhui University of Technology, Ma' anshan, PR (China)

    2014-01-15

    A facile hydrothermal strategy is proposed to synthesize flower-like β- Co(OH){sub 2} hierarchical microspherical superstructures with a diameter of 0.5-1.5 µm, which are self-assembled by β - Co(OH){sub 2} nano sheets with the average thickness ranging between 20 and 40 nm. The magnetocaloric effect associated with magnetic phase transitions in Co(OH){sub 2} superstructures has been investigated. A sign change in the magnetocaloric effect is induced by a magnetic field, which is related to a filed-induced transition from the antiferromagnetic to the ferromagnetic state below the Néel temperature. The large reversible magnetic-entropy change –ΔS{sub m} (13.4 J/kg K at 15 K for a field change of 5 T) indicates that flower-like Co(OH){sub 2} superstructures is a potential candidate for application in magnetic refrigeration in the low-temperature range. (author)

  9. Development of a new quantitative gas permeability method for dental implant-abutment connection tightness assessment

    Science.gov (United States)

    2011-01-01

    Background Most dental implant systems are presently made of two pieces: the implant itself and the abutment. The connection tightness between those two pieces is a key point to prevent bacterial proliferation, tissue inflammation and bone loss. The leak has been previously estimated by microbial, color tracer and endotoxin percolation. Methods A new nitrogen flow technique was developed for implant-abutment connection leakage measurement, adapted from a recent, sensitive, reproducible and quantitative method used to assess endodontic sealing. Results The results show very significant differences between various sealing and screwing conditions. The remaining flow was lower after key screwing compared to hand screwing (p = 0.03) and remained different from the negative test (p = 0.0004). The method reproducibility was very good, with a coefficient of variation of 1.29%. Conclusions Therefore, the presented new gas flow method appears to be a simple and robust method to compare different implant systems. It allows successive measures without disconnecting the abutment from the implant and should in particular be used to assess the behavior of the connection before and after mechanical stress. PMID:21492459

  10. [Influence of attachment type on stress distribution of implant-supported removable partial dentures].

    Science.gov (United States)

    Yang, Xue; Rong, Qi-guo; Yang, Ya-dong

    2015-02-18

    To compare influences of different retention attachments on stress among supporting structures. By 3-dimensional laser scanner and reverse engineering computer aided design (CAD) software, a basic partially edentulous digital model with mandibular premolar and molar missing was established. Implant attachment and removable partial dentures (RPD) were added into the basic model to build three kinds of models: RPD only, RPD + implant + Locator attachment, and RPD + implant + Magfit attachment. Vertical and inclined loads were put on artificial teeth unilaterally. By means of 3-dimensional finite element analysis, the stress distribution and displacement of the main supportive structures were compared. A complete 3-dimensional finite element model was established, which contained tooth structure, and periodontal structures. The displacement of the denture was smaller in Locator (9.38 μm vertically, 45.48 μm obliquely) and Magfit models (9.54 μm vertically, 39.45 μm obliquely) compared with non-implant RPD model (95.27 μm vertically, 155.70 μm obliquely). Compared with the two different attachments, cortical bone stress value was higher in Locator model (Locator model 10.850 MPa vertically, 43.760 MPa obliquely; Magfit model 7.100 MPa vertically, 19.260 MPa obliquely).The stress value of abutment periodontal ligamentin Magfit model (0.420 MPa vertically) was lower than that in Locator model (0.520 MPa vertically). The existence of implant could reduce maximum von Mises value of each supportive structure when Kennedy I partially edentulous mandible was restored. Comparing the structure of Magfit and Locator attachment, the contact of Magfit attachment was rigid, while Locator was resilient. Locator attachment could improve stability of the denture dramatically. Locator had stronger effect on defending horizontal movement of the denture.

  11. Progressive recovery of osseoperception as a function of the combination of implant-supported prostheses.

    Science.gov (United States)

    Batista, Mauro; Bonachela, Wellington; Soares, Janir

    2008-06-01

    The extraction of teeth involves the elimination of extremely sensitive periodontal mechanoreceptors, which play an important role in oral sensory perception. The aim of this study was to evaluate the recovery of interocclusal sensory perception for micro-thickness in individuals with different types of implant-supported prostheses. Wearers of complete dentures (CDs) comprised the negative control group (group A, n=17). The experimental group consisted of wearers of prostheses supported by osseointegrated implants (Group B, n=29), which was subsequently divided into 4 subgroups: B(1) (n=5)--implant supported overdentures (ISO) occluding with CD; B(2) (n=6)--implant-supported fixed prostheses (ISFP) occluding with CD; B(3) (n=8)--wearers of maxillary and mandibular ISFP, and B(4) (n=10)--ISFP occluding with natural dentition (ND). Individuals with ND represented the positive control group (Group C, n=24). Aluminum foils measuring 10 microm, 24 microm, 30 microm, 50 microm, 80 microm, and 104 microm thickness were placed within the premolar area, adding up to 120 tests for each individual. The mean tactile thresholds of groups A, B1, B2, B3, B4, and C were 92 microm, 27 microm, 27 microm, 14 microm, 10 microm, and 10 microm, respectively. [Correction added after publication online 18 April 2008: in the preceding sentence 92 microm, 27 microm, 14 microm, 10 microm and 10 microm, was corrected to 92 microm, 27 microm, 27 microm, 14 microm, 10 microm and 10 microm]. The Kruskal-Wallis test revealed significant difference among groups (P<0.05). The Dunn test revealed that group A was statistically different from groups C, B(3), and B(4), and that B(1) and B(2) were statistically different from group C. Progressive recovery of osseoperception as a function of the combination of implant-supported prostheses could be observed. Moreover, ISO and/or ISFP combinations may similarly maximize the recovery of osseoperception.

  12. Original computer aided support system for safe and accurate implant placement—Collaboration with an university originated venture company

    Directory of Open Access Journals (Sweden)

    Taiji Sohmura

    2010-08-01

    Two clinical cases with implant placement on the three lower molars by flap operation using bone supported surgical guide and flapless operation with teeth supported surgical guide and immediate loading with provisional prostheses prepared beforehand are introduced. The present simulation and drilling support using the surgical guide may help to perform safe and accurate implant surgery.

  13. Finite Element Analysis of the Effect of Superstructure Materials and Loading Angle on Stress Distribution around the Implant

    Directory of Open Access Journals (Sweden)

    Jafari K

    2014-12-01

    Full Text Available Statement of Problem: A general process in implant design is to determine the reason of possible problems and to find the relevant solutions. The success of the implant depends on the control technique of implant biomechanical conditions. Objectives: The goal of this study was to evaluate the influence of both abutment and framework materials on the stress of the bone around the implant by using threedimensional finite element analysis. Materials and Methods: A three-dimensional model of a patient’s premaxillary bone was fabricated using Cone Beam Computed Tomography (CBCT. Then, three types of abutment from gold, nickel-chromium and zirconia and also three types of crown frame from silver-palladium, nickel-chromium and zirconia were designed. Finally, a 178 N force at angles of zero, 30 and 45 degrees was exerted on the implant axis and the maximum stress and strain in the trabecular, cortical bones and cement was calculated. Results: With changes of the materials and mechanical properties of abutment and frame, little difference was observed in the level and distribution pattern of stress. The stress level was increased with the rise in the angle of pressure exertion. The highest stress concentration was related to the force at the angle of 45 degrees. The results of the cement analysis proved an inverse relationship between the rate of elastic modulus of the frame material and that of the maximum stress in the cement. Conclusions: The impact of the angle at which the force was applied was more significant in stress distribution than that of abutment and framework core materials.

  14. Enhanced thermophysical properties via PAO superstructure

    Science.gov (United States)

    Pournorouz, Zahra; Mostafavi, Amirhossein; Pinto, Aditya; Bokka, Apparao; Jeon, Junha; Shin, Donghyun

    2017-01-01

    For the last few years, molten salt nanomaterials have attracted many scientists for their enhanced specific heat by doping a minute concentration of nanoparticles (up to 1% by weight). Likewise, enhancing the specific heat of liquid media is important in many aspects of engineering such as engine oil, coolant, and lubricant. However, such enhancement in specific heat was only observed for molten salts, yet other engineering fluids such as water, ethylene glycol, and oil have shown a decrease of specific heat with doped nanoparticles. Recent studies have shown that the observed specific heat enhancement resulted from unique nanostructures that were formed by molten salt molecules when interacting with nanoparticles. Thus, such enhancement in specific heat is only possible for molten salts because other fluids may not naturally form such nanostructures. In this study, we hypothesized such nanostructures can be mimicked through in situ formation of fabricated nano-additives, which are putative nanoparticles coated with useful organic materials (e.g., polar-group-ended organic molecules) leading to superstructures, and thus can be directly used for other engineering fluids. We first applied this approach to polyalphaolefin (PAO). A differential scanning calorimeter (DSC), a rheometer, and a customized setup were employed to characterize the heat capacity, viscosity, and thermal conductivity of PAO and PAO with fabricated nano-additives. Results showed 44.5% enhanced heat capacity and 19.8 and 22.98% enhancement for thermal conductivity and viscosity, respectively, by an addition of only 2% of fabricated nanostructures in comparison with pure PAO. Moreover, a partial melting of the polar-group-ended organic molecules was observed in the first thermal cycle and the peak disappeared in the following cycles. This indicates that the in situ formation of fabricated nano-additives spontaneously occurs in the thermal cycle to form nanostructures. Figure of merit analyses have

  15. Enhanced thermophysical properties via PAO superstructure.

    Science.gov (United States)

    Pournorouz, Zahra; Mostafavi, Amirhossein; Pinto, Aditya; Bokka, Apparao; Jeon, Junha; Shin, Donghyun

    2017-12-01

    For the last few years, molten salt nanomaterials have attracted many scientists for their enhanced specific heat by doping a minute concentration of nanoparticles (up to 1% by weight). Likewise, enhancing the specific heat of liquid media is important in many aspects of engineering such as engine oil, coolant, and lubricant. However, such enhancement in specific heat was only observed for molten salts, yet other engineering fluids such as water, ethylene glycol, and oil have shown a decrease of specific heat with doped nanoparticles. Recent studies have shown that the observed specific heat enhancement resulted from unique nanostructures that were formed by molten salt molecules when interacting with nanoparticles. Thus, such enhancement in specific heat is only possible for molten salts because other fluids may not naturally form such nanostructures. In this study, we hypothesized such nanostructures can be mimicked through in situ formation of fabricated nano-additives, which are putative nanoparticles coated with useful organic materials (e.g., polar-group-ended organic molecules) leading to superstructures, and thus can be directly used for other engineering fluids. We first applied this approach to polyalphaolefin (PAO). A differential scanning calorimeter (DSC), a rheometer, and a customized setup were employed to characterize the heat capacity, viscosity, and thermal conductivity of PAO and PAO with fabricated nano-additives. Results showed 44.5% enhanced heat capacity and 19.8 and 22.98% enhancement for thermal conductivity and viscosity, respectively, by an addition of only 2% of fabricated nanostructures in comparison with pure PAO. Moreover, a partial melting of the polar-group-ended organic molecules was observed in the first thermal cycle and the peak disappeared in the following cycles. This indicates that the in situ formation of fabricated nano-additives spontaneously occurs in the thermal cycle to form nanostructures. Figure of merit analyses have

  16. Effects of elevated ambient temperature on embryo implantation in rats

    African Journals Online (AJOL)

    Yomi

    2012-03-22

    Mar 22, 2012 ... ambient temperature leads to a delayed implantation and reduced number of implantation sites in. Sprague ... rates decrease after exposure to stress. One of the ..... implantation initiation time, support the previous findings.

  17. Theoretical role of adjunctive implant positional support in stress distribution of distal-extension mandibular removable partial dentures.

    Science.gov (United States)

    Xiao, Wei; Li, Zhiyong; Shen, Shiqian; Chen, Shaowu; Wang, Yining; Wang, Jiawei

    2014-01-01

    This preliminary study evaluated the adjunctive supporting role of diverse implant positions on stress distribution in a Class I removable partial denture (RPD) design. Nine three-dimensional finite element models were prepared to simulate mandibular RPD designs with three different loading conditions applied. Implant supported designs demonstrated lower stress value concentrations and mucosal displacement.

  18. Linking experiment and theory for three-dimensional networked binary metal nanoparticle–triblock terpolymer superstructures

    KAUST Repository

    Li, Zihui; Hur, Kahyun; Sai, Hiroaki; Higuchi, Takeshi; Takahara, Atsushi; Jinnai, Hiroshi; Gruner, Sol M.; Wiesner, Ulrich

    2014-01-01

    the intimate coupling of synthesis, in-depth electron tomographic characterization and theory enables exquisite control of superstructure in highly ordered porous three-dimensional continuous networks from single and binary mixtures of metal nanoparticles

  19. Dichotic Listening Can Improve Perceived Clarity of Music in Cochlear Implant Users.

    Science.gov (United States)

    Vannson, Nicolas; Innes-Brown, Hamish; Marozeau, Jeremy

    2015-08-26

    Musical enjoyment for cochlear implant (CI) recipients is often reported to be unsatisfactory. Our goal was to determine whether the musical experience of postlingually deafened adult CI recipients could be enriched by presenting the bass and treble clef parts of short polyphonic piano pieces separately to each ear (dichotic). Dichotic presentation should artificially enhance the lateralization cues of each part and help the listeners to better segregate them and thus provide greater clarity. We also hypothesized that perception of the intended emotion of the pieces and their overall enjoyment would be enhanced in the dichotic mode compared with the monophonic (both parts in the same ear) and the diotic mode (both parts in both ears). Twenty-eight piano pieces specifically composed to induce sad or happy emotions were selected. The tempo of the pieces, which ranged from lento to presto covaried with the intended emotion (from sad to happy). Thirty participants (11 normal-hearing listeners, 11 bimodal CI and hearing-aid users, and 8 bilaterally implanted CI users) participated in this study. Participants were asked to rate the perceived clarity, the intended emotion, and their preference of each piece in different listening modes. Results indicated that dichotic presentation produced small significant improvements in subjective ratings based on perceived clarity and preference. We also found that preference and clarity ratings were significantly higher for pieces with fast tempi compared with slow tempi. However, no significant differences between diotic and dichotic presentation were found for the participants' preference ratings, or their judgments of intended emotion. © The Author(s) 2015.

  20. Dichotic Listening Can Improve Perceived Clarity of Music in Cochlear Implant Users

    Directory of Open Access Journals (Sweden)

    Nicolas Vannson

    2015-08-01

    Full Text Available Musical enjoyment for cochlear implant (CI recipients is often reported to be unsatisfactory. Our goal was to determine whether the musical experience of postlingually deafened adult CI recipients could be enriched by presenting the bass and treble clef parts of short polyphonic piano pieces separately to each ear (dichotic. Dichotic presentation should artificially enhance the lateralization cues of each part and help the listeners to better segregate them and thus provide greater clarity. We also hypothesized that perception of the intended emotion of the pieces and their overall enjoyment would be enhanced in the dichotic mode compared with the monophonic (both parts in the same ear and the diotic mode (both parts in both ears. Twenty-eight piano pieces specifically composed to induce sad or happy emotions were selected. The tempo of the pieces, which ranged from lento to presto covaried with the intended emotion (from sad to happy. Thirty participants (11 normal-hearing listeners, 11 bimodal CI and hearing-aid users, and 8 bilaterally implanted CI users participated in this study. Participants were asked to rate the perceived clarity, the intended emotion, and their preference of each piece in different listening modes. Results indicated that dichotic presentation produced small significant improvements in subjective ratings based on perceived clarity. We also found that preference and clarity ratings were significantly higher for pieces with fast tempi compared with slow tempi. However, no significant differences between diotic and dichotic presentation were found for the participants’ preference ratings, or their judgments of intended emotion.

  1. Biomechanical evaluation of the natural abutment teeth in combined tooth-implant-supported telescopic prostheses: a three-dimensional finite element analysis.

    Science.gov (United States)

    Chen, Yu; Wang, Chao; Huang, Yuanding; Feng, Tianming; Zou, Huawei; Fan, Yubo

    2017-07-01

    Telescopic overdentures supported by the combination of natural teeth and implants have been thought a valuable treatment for the severely compromised partially edentulous patients. But the combination of teeth and implants involves highly complex biomechanical problems. This study is to evaluate biomechanical behaviors of the natural abutment teeth with the treatment of combined tooth-implant supported telescopic crown prostheses in mandible through 3D FEA. According to this study, the prosthetic option supported by a combination of teeth and implants and retained by double crowns could protect teeth and their periodontal support tissues acting as a rigid splint, and may be a valuable treatment option for partially edentulous patients with severely reduced remaining teeth in mandible.

  2. DEPENDENCIES TO DETERMINE THE MEASURE OF DAMAGE AND CALCULATION OF RESIDUAL LIFE OF REINFORCED CONCRETE SUPERSTRUCTURE, EXPOSED TO SALT CORROSION

    OpenAIRE

    SAATOVA NODIRA ZIYAYEVNA

    2016-01-01

    In this paper we consider the current method of determining the measure of damage of concrete and reinforcement. The proposed dependence measures of damage, convenient for use in predicting the life of structures superstructures.The practical method of calculation determination of residual resource of the exploited superstructures developed. The main source of data for calculating the residual life are the parameters defined by the technical diagnosis.

  3. Bone healing response in cyclically loaded implants: Comparing zero, one, and two loading sessions per day.

    Science.gov (United States)

    de Barros E Lima Bueno, Renan; Dias, Ana Paula; Ponce, Katia J; Wazen, Rima; Brunski, John B; Nanci, Antonio

    2018-05-31

    When bone implants are loaded, they are inevitably subjected to displacement relative to bone. Such micromotion generates stress/strain states at the interface that can cause beneficial or detrimental sequels. The objective of this study is to better understand the mechanobiology of bone healing at the tissue-implant interface during repeated loading. Machined screw shaped Ti implants were placed in rat tibiae in a hole slightly bigger than the implant diameter. Implants were held stable by a specially-designed bone plate that permits controlled loading. Three loading regimens were applied, (a) zero loading, (b) one daily loading session of 60 cycles with an axial force of 1.5 N/cycle for 7 days, and (c) two such daily sessions with the same axial force also for 7 days. Finite element analysis was used to characterize the mechanobiological conditions produced by the loading sessions. After 7 days, the implants with surrounding interfacial tissue were harvested and processed for histological, histomorphometric and DNA microarray analyses. Histomorphometric analyses revealed that the group subjected to repeated loading sessions exhibited a significant decrease in bone-implant contact and increase in bone-implant distance, as compared to unloaded implants and those subjected to only one loading session. Gene expression profiles differed during osseointegration between all groups mainly with respect to inflammatory and unidentified gene categories. The results indicate that increasing the daily cyclic loading of implants induces deleterious changes in the bone healing response, most likely due to the accumulation of tissue damage and associated inflammatory reaction at the bone-implant interface. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. All on Four® fixed implant support rehabilitation: a masticatory function study.

    Science.gov (United States)

    De Rossi, Moara; Santos, Carla Moreto; Migliorança, Reginaldo; Regalo, Simone Cecílio Hallak

    2014-08-01

    Fixed implant-supported prostheses according to All-on-Four® (Nobel Biocare, Goteborg, Sweden) principles have become an accepted treatment modality in totally edentulous patients, whereas the functional effect of this therapy is limited. The purpose of this study was to evaluate the muscular function of patients totally rehabilitated with All-on-Four. This study evaluated 63 patients. Twenty-one patients were successfully rehabilitated with maxillary and mandibular All-on-Four (no dropout implants, satisfactory aesthetic and function demands prosthesis), 21 patients were dentate, and 21 were rehabilitated with double complete dentures. Electromyography was carried out during clenching, nonhabitual and habitual chewing, and rest. All values were standardized as percentage of a maximum voluntary contraction. Data were analyzed by ANOVA to compare groups and paired t-test was used for comparison between sides within each group. All groups presented symmetric muscular activity. The All-on-Four and dentate groups had a similar muscles surface electromyography (sEMG) contraction pattern, that is, a higher sEMG activity of masseter than temporalis muscles, differing (p ≤ .05) from those of denture group. Not one statistical difference was found between All-on-Four and dentate groups. The muscular function similarity of All-on-Four and dentate patients shows that this treatment concept may be considered as a good option for oral rehabilitation in edentulous patients. © 2013 Wiley Periodicals, Inc.

  5. Self-assembly of polyhedral metal–organic framework particles into three-dimensional ordered superstructures

    NARCIS (Netherlands)

    Avci, Civan; Imaz, Inhar; Carné-Sánchez, Arnau; Pariente, Jose Angel; Tasios, Nikos; Pérez-Carvajal, Javier; Alonso, Maria Isabel; Blanco, Alvaro; Dijkstra, M.; López, Cefe; Maspoch, Daniel

    Self-assembly of particles into long-range, three-dimensional, ordered superstructures is crucial for the design of a variety of materials, including plasmonic sensing materials, energy or gas storage systems, catalysts and photonic crystals. Here, we have combined experimental and simulation data

  6. Proximity annealing of sulfur-implanted gallium arsenide using a strip heater

    International Nuclear Information System (INIS)

    Banerjee, S.; Baker, J.

    1985-01-01

    A graphite strip heater has been employed for rapid (-- 30 s) thermal annealing (RTA), at temperatures between 850 and 1150 0 C, of Cr-doped GaAs implanted with 120 keV 32 S + with doses between 10 13 and 10 15 cm -2 . In order to minimize the incongruent evaporation of As, proximity anneals were employed by protecting the implanted samples with GaAs cover pieces. RTA yields electrical activation and donor mobilities better than or comparable to furnace annealing, with less redistribution of the implanted S and background Cr. (author)

  7. Fuel assembly supporting structure

    International Nuclear Information System (INIS)

    Aisch, F.W.; Fuchs, H.P.; Knoedler, D.; Steinke, A.; Steven, J.

    1976-01-01

    For use in forming the core of a pressurized-water reactor, a fuel assembly supporting structure for holding a bundle of interspaced fuel rods, is formed by interspaced end pieces having holes in which the end portions of control rod guide tubes are inserted, fuel rod spacer grids being positioned by these guide tubes between the end pieces. The end pieces are fastened to the end portions of the guide tubes, to integrate the supporting structure, and in the case of at least one of the end pieces, this is done by means which releases that end piece from the guide tubes when the end pieces receive an abnormal thrust force directed towards each other and which would otherwise place the guide tubes under a compressive stress that would cause them to buckle. The spacer grids normally hold the fuel rods interspaced by distances determined by nuclear physics, and buckling of the control rod guide tubes can distort the fuel rod spacer grids with consequent dearrangement of the fuel rod interspacing. A sudden loss of pressure in a pressurized-water reactor pressure vessel can result in the pressurized coolant in the vessel discharging from the vessel at such high velocity as to result in the abnormal thrust force on the end pieces of each fuel assembly, which could cause buckling of the control rod guide tubes when the end pieces are fixed to them in the normal rigid and unyielding manner

  8. A 2-year report on maxillary and mandibular fixed partial dentures supported by Astra Tech dental implants. A comparison of 2 implants with different surface textures

    DEFF Research Database (Denmark)

    Karlsson, U; Gotfredsen, K; Olsson, C

    1998-01-01

    In 50 partially edentulous patients, 133 (48 maxillary; 85 mandibular) Astra Tech dental implants of 2 different surface textures (machined; TiO-blasted) were alternately installed, supporting 52 fixed partial dentures (FPDs). Before abutment connection 2 machined implants (1 mandibular; 1...

  9. Pieces

    DEFF Research Database (Denmark)

    Jensen, Niels Henrik

    1990-01-01

    The report presents results from the SIP project (System Representation in Process Control). PIECES is a graphical, interactive user interface system designed and programmed as a tool for building, manipulating and using a Multilevel Flow Model (MFM - Morten Lind, Tecnical University of Denmark)....

  10. A 5-year prospective study of single-tooth replacements supported by the Astra Tech implant: a pilot study

    DEFF Research Database (Denmark)

    Gotfredsen, Klaus

    2004-01-01

    BACKGROUND: Implant-supported single-tooth replacements are an increasingly used method to replace teeth, especially in young patients. Therefore, long-term validation of different treatment modalities with different implant systems is of great importance. PURPOSE: The aim of the present study...... was to make a biologic, technical, and aesthetic evaluation of single-tooth replacement supported by the Astra Tech implant (Astra Tech AB, Mölndal, Sweden) during a 5-year period. MATERIALS AND METHODS: Twenty patients were divided into two consecutively treated groups. In group A the implants were placed...... "early" in the extraction sockets, and standard single-tooth abutments were used. In group B the implants were placed "delayed," and preparable abutments were used. Clinical examinations including registration of plaque, bleeding, crown lengths, soft tissue marginal level, papilla height, complications...

  11. Strain analysis of different diameter Morse taper implants under overloading compressive conditions

    Directory of Open Access Journals (Sweden)

    Carolina Guimarães CASTRO

    2015-01-01

    Full Text Available The aim of this study was to evaluate the amount of deformation from compression caused by different diameters of Morse taper implants and the residual deformation after load removal. Thirty Morse taper implants lacking external threads were divided into 3 groups (n = 10 according to their diameter as follows: 3.5 mm, 4.0 mm and 5.0 mm. Two-piece abutments were fixed into the implants, and the samples were subjected to compressive axial loading up to 1500 N of force. During the test, one strain gauge remained fixed to the cervical portion of each implant to measure the strain variation. The strain values were recorded at two different time points: at the maximum load (1500 N and 60 seconds after load removal. To calculate the strain at the implant/abutment interface, a mathematical formula was applied. Data were analyzed using a one-way Anova and Tukey’s test (α = 0.05. The 5.0 mm diameter implant showed a significantly lower strain (650.5 μS ± 170.0 than the 4.0 mm group (1170.2 μS ± 374.7 and the 3.5 mm group (1388.1 μS ± 326.6 (p < 0.001, regardless of the load presence. The strain values decreased by approximately 50% after removal of the load, regardless of the implant diameter. The 5.0 mm implant showed a significantly lower strain at the implant/abutment interface (943.4 μS ± 504.5 than the 4.0 mm group (1057.4 μS ± 681.3 and the 3.5 mm group (1159.6 μS ± 425.9 (p < 0.001. According to the results of this study, the diameter influenced the strain around the internal and external walls of the cervical region of Morse taper implants; all diameters demonstrated clinically acceptable values of strain.

  12. A support shield for a powered support

    Energy Technology Data Exchange (ETDEWEB)

    Korczynski, P; Rojicek, P

    1982-08-31

    The subject of this invention is a support shield for a powered support. This shield resists creep of the coal from the longwall face, including an inclined longwall. It involves an arrangement wherein the distributor hinge is separated into upper and lower sections. The lower section holds a second hinge and the end of the rod of the pressure cylinder, one end of which is connected to the roof support. An advantage of the support is that compared to existing supports, it is self-advancing and holds stopes with coal which slopes in its formation or has inrushes. To a certain degree it prevents the stope space from ejecting fine pieces of rock from the longwall roof using an inter-timber support between the powered support and the stope. The support shield is moved by a simple system of levers which makes it possible, using a pressurized cylinder, to transmit a significant force to the coal stope. In this case, when the coal inrushes exceed the designed capabilities of the shield, a wooden extension piece is placed between the support and the face, through which the support pressure is applied.

  13. Observation of Vacancies, Faults, and Superstructures in Ln5Mo2O12 (Ln = La, Y, and Lu) Compounds with Direct Mo-Mo Bonding.

    Science.gov (United States)

    Colabello, Diane M; Sobalvarro, Elizabeth M; Sheckelton, John P; Neuefeind, Joerg C; McQueen, Tyrel M; Khalifah, Peter G

    2017-11-06

    Among oxide compounds with direct metal-metal bonding, the Y 5 Mo 2 O 12 (A 5 B 2 O 12 ) structural family of compounds has a particularly intriguing low-dimensional structure due to the presence of bioctahedral B 2 O 10 dimers arranged in one-dimensional edge-sharing chains along the direction of the metal-metal bonds. Furthermore, these compounds can have a local magnetic moment due to the noninteger oxidation state (+4.5) of the transition metal, in contrast to the conspicuous lack of a local moment that is commonly observed when oxide compounds with direct metal-metal bonding have integer oxidation states resulting from the lifting of orbital degeneracy typically induced by the metal-metal bonding. Although a monoclinic C2/m structure has been previously proposed for Ln 5 Mo 2 O 12 (Ln = La-Lu and Y) members of this family based on prior single crystal diffraction data, it is found that this structural model misses many important structural features. On the basis of synchrotron powder diffraction data, it is shown that the C2/m monoclinic unit cell represents a superstructure relative to a previously unrecognized orthorhombic Immm subcell and that the superstructure derives from the ordering of interchangeable Mo 2 O 10 and LaO 6 building blocks. The superstructure for this reason is typically highly faulted, as evidenced by the increased breadth of superstructure diffraction peaks associated with a coherence length of 1-2 nm in the c* direction. Finally, it is shown that oxygen vacancies can occur when Ln = La, producing an oxygen deficient stoichiometry of La 5 Mo 2 O 11.55 and an approximately 10-fold reduction in the number of unpaired electrons due to the reduction of the average Mo valence from +4.5 to +4.05, a result confirmed by magnetic susceptibility measurements. This represents the first observation of oxygen vacancies in this family of compounds and provides an important means of continuously tuning the magnetic interactions within the one

  14. Survival of Implants in Immediate Extraction Sockets of Anterior Teeth: Early Clinical Results.

    Science.gov (United States)

    Sabir, Mohammad; Alam, Mohammad Nazish

    2015-06-01

    The aims and objectives of this study were placement of implants in freshly extracted sockets of anterior teeth and to evaluate the implant stability, peri-implant radiolucency and gingival inflammation around implant over a short period of 30 months. A total of 12 patients (8 male and 4 female), ranging in the age from 20 to 50 years, from March 2007 to June 2007, were evaluated for immediate implant placement into 22 fresh extraction sockets. Only maxillary and mandibular anterior teeth/roots (central incisors, lateral incisors and canines) were considered for replacement with implants. One piece implant with integrated abutment and integrated surface, non-submerged, threaded and tapered at apical 5 mm, sand-blasted and acid etched surfaced implants (HI-TEC TRX-OP Implants of Life Care Company) were used. The mobility was not present in any of the implants at all the follow up visits. There were 2 implants at 6 month, 1 implant at 12 month, 1 implant at 18 month visits, showing peri-implant radiolucency at some sites at bone to implant contact site. Severe gingival inflammation was not observed in any of the implant site. At every follow-up visit, every implant met the criteria of success and none was found to be failed over a 30 months duration i.e. 100% success rate was achieved by implants in immediate extraction socket. The success rate of implant survival in this study was found 100%. These implants have fulfilled all the criteria of implant success and based on the defined criteria, the success rate of implants placed in immediate extraction sockets of anterior teeth compared favorably with the conventional implants. The early results of the present study showed that high survival rates with the implants in immediate extraction sockets can be achieved.

  15. Establishing contact between cell-laden hydrogels and metallic implants with a biomimetic adhesive for cell therapy supported implants.

    Science.gov (United States)

    Barthes, Julien; Mutschler, Angela; Dollinger, Camille; Gaudinat, Guillaume; Lavalle, Philippe; Le Houerou, Vincent; Brian McGuinness, Garrett; Engin Vrana, Nihal

    2017-12-15

    For in-dwelling implants, controlling the biological interface is a crucial parameter to promote tissue integration and prevent implant failure. For this purpose, one possibility is to facilitate the establishment of the interface with cell-laden hydrogels fixed to the implant. However, for proper functioning, the stability of the hydrogel on the implant should be ensured. Modification of implant surfaces with an adhesive represents a promising strategy to promote the adhesion of a cell-laden hydrogel on an implant. Herein, we developed a peptidic adhesive based on mussel foot protein (L-DOPA-L-lysine) 2 -L-DOPA that can be applied directly on the surface of an implant. At physiological pH, unoxidized (L-DOPA-L-lysine) 2 -L-DOPA was supposed to strongly adhere to metallic surfaces but it only formed a very thin coating (less than 1 nm). Once oxidized at physiological pH, (L-DOPA-L-lysine) 2 -L-DOPA forms an adhesive coating about 20 nm thick. In oxidized conditions, L-lysine can adhere to metallic substrates via electrostatic interaction. Oxidized L-DOPA allows the formation of a coating through self-polymerization and can react with amines so that this adhesive can be used to fix extra-cellular matrix based materials on implant surfaces through the reaction of quinones with amino groups. Hence, a stable interface between a soft gelatin hydrogel and metallic surfaces was achieved and the strength of adhesion was investigated. We have shown that the adhesive is non-cytotoxic to encapsulated cells and enabled the adhesion of gelatin soft hydrogels for 21 days on metallic substrates in liquid conditions. The adhesion properties of this anchoring peptide was quantified by a 180° peeling test with a more than 60% increase in peel strength in the presence of the adhesive. We demonstrated that by using a biomimetic adhesive, for the application of cell-laden hydrogels to metallic implant surfaces, the hydrogel/implant interface can be ensured without relying on the

  16. 76 FR 55708 - Servicing Multi-Piece and Single Piece Rim Wheels; Extension of the Office of Management and...

    Science.gov (United States)

    2011-09-08

    ...] Servicing Multi-Piece and Single Piece Rim Wheels; Extension of the Office of Management and Budget's (OMB... concerning its proposal to extend the Office of Management and Budget's (OMB) approval of the information collection requirements specified in the Standard on Servicing Multi-Piece and Single Piece Rim Wheels (29...

  17. A simplified method to reduce prosthetic misfit for a screw-retained, implant-supported complete denture using a luting technique and laser welding.

    Science.gov (United States)

    Longoni, Salvatore; Sartori, Matteo; Davide, Roberto

    2004-06-01

    An important aim of implant-supported prostheses is to achieve a passive fit of the framework with the abutments to limit the amount of stress transfer to the bone-implant interface. An efficient and standardized technique is proposed. A definitive screw-retained, implant-supported complete denture was fabricated for an immediately loaded provisional screw-retained implant-supported complete denture. Precise fit was achieved by the use of industrial titanium components and the passivity, by an intraoral luting sequence and laser welding.

  18. Rehabilitation with implant-supported overdentures in total edentulous patients: A review

    OpenAIRE

    Martínez–Lage-Azorín, Juan F.; Segura-Andrés, Gustavo; Faus-López, Joan; Agustín-Panadero, Rubén

    2013-01-01

    Objectives: The main aim of this review article is to discuss implant-supported overdentures (ISOs) as treatment in edentulous patients. Besides, we will try to discuss among the different treatment options in such patients and to analyze their validity when ISOs are compared with other clinical modalities. At the same time, we will try to suggest clinical guidelines supported by current clinical studies. Material and methods: We performed a Medline search and review of pertinent articles on ...

  19. Pay Matters: The Piece Rate and Health in the Developing World.

    Science.gov (United States)

    Davis, Mary E

    Piece rate pay remains a common form of compensation in developing-world industries. While the piece rate may boost productivity, it has been shown to have unintended consequences for occupational safety and health, including increased accident and injury risk. This paper explores the relationship between worker pay and physical and emotional health, and questions the modern day business case for piece rate pay in the developing world. The relationship between piece rate and self-reported measures of physical and emotional health is estimated using a large survey of garment workers in 109 Vietnamese factories between 2010 and 2014. A random effects logit model controls for factory and year, predicting worker health as a function of pay type, demographics, and factory characteristics. Workers paid by the piece report worse physical and emotional health than workers paid by the hour (OR = 1.38-1.81). Wage incentives provide the most consistently significant evidence of all demographic and factory-level variables, including the factory's own performance on occupational safety and health compliance measures. These results highlight the importance of how workers are paid to understanding the variability in worker health outcomes. More research is needed to better understand the business case supporting the continued use of piece rate pay in the developing world. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

  20. Improvement of a microwave ECR plasma source for the plasma immersion ion implantation and deposition process

    International Nuclear Information System (INIS)

    Wu Hongchen; Zhang Huafang; Peng Liping; Jiang Yanli; Ma Guojia

    2004-01-01

    The Plasma Immersion Ion Implantation and Deposition (PIII and D) process has many advantages over the pure plasma immersion ion implantation or deposition. It can compensate for or eliminate the disadvantages of the shallow modification layer (for PIII) and increase the bond strength of the coating (of deposition). For this purpose, a new type of microwave plasma source used in the PIII and D process was developed, composed of a vacuum bend wave guide and a special magnetic circuit, so that the coupling window was protected from being deposited with a coating and bombarded by high-energy particles. So the life of the window is increased. To enhance the bonding between the coating and substrate a new biasing voltage is applied to the work piece so that the implantation and deposition (or hybrid process) can be completed in one vacuum cycle

  1. Optimal processing pathway for the production of biodiesel from microalgal biomass: A superstructure based approach

    DEFF Research Database (Denmark)

    Rizwan, Muhammad; Lee, Jay H.; Gani, Rafiqul

    2013-01-01

    In this study, we propose a mixed integer nonlinear programming (MINLP) model for superstructure based optimization of biodiesel production from microalgal biomass. The proposed superstructure includes a number of major processing steps for the production of biodiesel from microalgal biomass......, such as the harvesting of microalgal biomass, pretreatments including drying and cell disruption of harvested biomass, lipid extraction, transesterification, and post-transesterfication purification. The proposed model is used to find the optimal processing pathway among the large number of potential pathways that exist...... for the production of biodiesel from microalgae. The proposed methodology is tested by implementing on a specific case with different choices of objective functions. The MINLP model is implemented and solved in GAMS using a database built in Excel. The results from the optimization are analyzed...

  2. Implanted-tritium permeation experiments

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Holland, D.F.; Casper, L.A.; Hsu, P.Y.; Miller, L.G.; Schmunk, R.E.; Watts, K.D.; Wilson, C.J.; Kershner, C.J.; Rogers, M.L.

    1982-04-01

    In fusion reactors, charge exchange neutral atoms of tritium coming from the plasma will be implanted into the first wall and other interior structures. EG and G Idaho is conducting two experiments to determine the magnitude of permeation into the coolant streams and the retention of tritium in those structures. One experiment uses an ion gun to implant deuterium. The ion gun will permit measurements to be made for a variety of implantation energies and fluxes. The second experiment utilizes a fission reactor to generate a tritium implantation flux by the 3 He(n,p) 3 H reaction. This experiment will simulate the fusion reactor radiation environment. We also plan to verify a supporting analytical code development program, in progress, by these experiments

  3. Complications and patient-centered outcomes with an implant-supported monolithic zirconia fixed dental prosthesis: 1 year results.

    Science.gov (United States)

    Limmer, Bryan; Sanders, Anne E; Reside, Glenn; Cooper, Lyndon F

    2014-06-01

    To characterize the number and type of complications that occur with a monolithic zirconia fixed dental prosthesis (MZ-FDP) supported by four endosseous implants in the edentulous mandible over time and to quantify the impact of treatment on oral health quality of life (OHQoL). Seventeen edentulous participants were enrolled. New conventional dentures were fabricated for each participant. Four Astra Tech Osseospeed TX implants (Dentsply) were then placed in the parasymphyseal mandible, and after a period of healing, a full-arch monolithic zirconia prosthesis (Zirkonzahn) was inserted. Complication data were recorded and OHQoL was evaluated using the Oral Health Impact Profile (OHIP-49), administered on four occasions: enrollment; implant surgery; and 6- and 12-month recalls. Sixty-eight implants were placed in 17 edentulous individuals aged 30 to 78 (mean 57.9 years). Implant survival was 94% from the subject perspective and 99% from the implant perspective. Prosthesis survival was 88%. Twelve complications occurred in ten participants, whereas seven participants remained complication free. Both OHIP-49 severity and extent scores decreased significantly between enrollment and 12-month recall (p < 0.001). The mean OHIP-49 severity score at baseline was 94.8 (95% confidence interval [CI]: 73.9, 115.8) and declined an average of 76.8 (95% CI: -91.3, -62.3) units per participant. The mean OHIP-49 extent score at baseline was 17.2 (95% CI: 10.8, 23.6) and declined 16.3 (95% CI: -20.2, -12.4) units per participant on average. Implant survival was high, and few complications related to the MZ-FDP were observed. The most common prosthetic complication was tooth chipping in the opposing maxillary denture, which accounted for 50% of all complication events. Substantial and clinically important improvements in OHQoL were achieved with both conventional dentures and the implant-supported MZ-FDP. The data of this short-term study indicate that the implant-supported MZ-FDP is a

  4. Evaluation of marginal fit of single implant-supported metal-ceramic crowns prepared by using presintered metal blocks.

    Science.gov (United States)

    Pasali, Baris; Sarac, Duygu; Kaleli, Necati; Sarac, Yakup Sinasi

    2018-02-01

    Recently, presintered metal blocks for nonprecious and precious metal implant-supported restorations have gained popularity in computer-aided design and computer-aided manufacturing (CAD-CAM) systems. However, few studies have evaluated the marginal discrepancy of implant-supported restorations made with these new alloy systems. The purpose of this in vitro study was to compare the milling-sintering method with the lost-wax and milling methods in terms of the marginal fit of implant-supported metal-ceramic restorations. Thirty implant abutments screwed to implant analogs were embedded into acrylic resin to investigate marginal fit and then divided according to fabrication methods into the following 3 groups (n=10): lost-wax (LW; control group), milling (M), and milling-sintering (MS). Porcelain material was applied to all specimens after completion of the fabrication process. Subsequently, all specimens were cemented to implant abutments for the measurement of marginal discrepancies. Twelve marginal discrepancy measurements were recorded on each implant abutment by using a stereomicroscope. The arithmetic mean of these 12 measurements was considered the mean marginal discrepancy value of each abutment. Data were statistically analyzed by using 1-way ANOVA and Tukey honest significant difference tests (α=.05). The lowest mean marginal discrepancy values (81 ±2 μm) were observed in the M group, which was significantly different (Pmarginal discrepancy values (99 ±2 μm) were observed in the MS group. The results revealed that restorations prepared by the milling-sintering method provided clinically acceptable results (marginal fit. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  5. A prospective 5-year study of fixed partial prostheses supported by implants with machined and TiO2-blasted surface

    DEFF Research Database (Denmark)

    Gotfredsen, K; Karlsson, U

    2001-01-01

    PURPOSE: The aim of the present study was to evaluate whether there was a difference between machined and TiO(2)-blasted implants regarding survival rate and marginal bone loss during a 5-year observation period. MATERIALS AND METHODS: A total of 133 implants (Astra Tech Dental Implants; Astra Tech...... AB, Mölndal, Sweden) were placed in 50 patients at 6 centers in 4 Scandinavian countries. Forty-eight implants were installed in the maxilla and 85 implants in the mandible. A randomization and a stratification were done, so that each fixed partial prosthesis was supported by at least 1 machined...... and 1 TiO(2)-blasted implant. The implant-supported fixed partial prostheses (ISFPP) were fabricated within 2 months after postoperative healing. A total of 52 ISFPP (17 maxillary, 35 mandibular) were inserted. The patients were clinically examined once a year for 5 years. At the annual follow...

  6. Imunohistological aspects of the tissue around dental implants

    Science.gov (United States)

    Nimigean, Victor; Nimigean, Vanda R.; Sǎlǎvǎstru, Dan I.; Moraru, Simona; BuÅ£incu, Lavinia; Ivaşcu, Roxana V.; Poll, Alexandru

    2016-03-01

    Objectives: study of soft and hard tissues around implants. Material and methods: For the immunohistochemical and histological study of the implant/soft tissue interface, we examined pieces of peri-implant mucosa harvested from 35 patients. The implant/bone interface was assessed using histologic and histomorphometric examination of hard tissues around unloaded, early loaded or delayed loaded dental implants with pre-established design, with a sandblasted and acid-etched surface, placed both in extraction sockets, or after bone healing following tooth removal. This study was performed on 9 common race dogs. Results: The histological study of the implant/soft tissue interface showed regenerative modifications and moderate chronic subepithelial inflammatory reactions. Immunohistochemical evaluation of the soft tissue biopsies revealed the presence of specific immunocompetent cells and proteins of the matrix metalloproteinase (MMP) expression. Bone-implants contacts were more obvious in the apical half of the implants and at the edges of the threads, than between them. A mature, lamelliform bone containing lacunae with osteocytes and lack of connective tissue were noticed around implants that were late placed and loaded. The new-formed bone was also abundant in the crestal zone, not only in the apical part of the implants. Conclusions: A thorough understanding of the microstructure of dental implant/soft and hard tissue interface will improve the longevity of osseointegrated implants.

  7. Gallium ion implantation greatly reduces thermal conductivity and enhances electronic one of ZnO nanowires

    Directory of Open Access Journals (Sweden)

    Minggang Xia

    2014-05-01

    Full Text Available The electrical and thermal conductivities are measured for individual zinc oxide (ZnO nanowires with and without gallium ion (Ga+ implantation at room temperature. Our results show that Ga+ implantation enhances electrical conductivity by one order of magnitude from 1.01 × 103 Ω−1m−1 to 1.46 × 104 Ω−1m−1 and reduces its thermal conductivity by one order of magnitude from 12.7 Wm−1K−1 to 1.22 Wm−1K−1 for ZnO nanowires of 100 nm in diameter. The measured thermal conductivities are in good agreement with those in theoretical simulation. The increase of electrical conductivity origins in electron donor doping by Ga+ implantation and the decrease of thermal conductivity is due to the longitudinal and transverse acoustic phonons scattering by Ga+ point scattering. For pristine ZnO nanowires, the thermal conductivity decreases only two times when its diameter reduces from 100 nm to 46 nm. Therefore, Ga+-implantation may be a more effective method than diameter reduction in improving thermoelectric performance.

  8. Photoelastic analysis of mandibular full-arch implant-supported fixed dentures made with different bar materials and manufacturing techniques.

    Science.gov (United States)

    Zaparolli, Danilo; Peixoto, Raniel Fernandes; Pupim, Denise; Macedo, Ana Paula; Toniollo, Marcelo Bighetti; Mattos, Maria da Glória Chiarello de

    2017-12-01

    To compare the stress distribution of mandibular full dentures supported with implants according to the bar materials and manufacturing techniques using a qualitative photoelastic analysis. An acrylic master model simulating the mandibular arch was fabricated with four Morse taper implant analogs of 4.5×6mm. Four different bars were manufactured according to different material and techniques: fiber-reinforced resin (G1, Trinia, CAD/CAM), commercially pure titanium (G2, cpTi, CAD/CAM), cobalt‑chromium (G3, Co-Cr, CAD/CAM) and cobalt‑chromium (G4, Co-Cr, conventional cast). Standard clinical and laboratory procedures were used by an experienced dental technician to fabricate 4 mandibular implant-supported dentures. The photoelastic model was created based on the acrylic master model. A load simulation (150N) was performed in total occlusion against the antagonist. Dentures with fiber-reinforced resin bar (G1) exhibited better stress distribution. Dentures with machined Co-Cr bar (G3) exhibited the worst standard of stress distribution, with an overload on the distal part of the posteriors implants, followed by dentures with cast Co-Cr bar (G4) and machined cpTi bar (G2). The fiber-reinforced resin bar exhibited an adequate stress distribution and can serve as a viable alternative for oral rehabilitation with mandibular full dentures supported with implants. Moreover, the use of the G1 group offered advantages including reduced weight and less possible overload to the implants components, leading to the preservation of the support structure. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Evolution of impedance field telemetry after one day of activation in cochlear implant recipients.

    Directory of Open Access Journals (Sweden)

    Hao-Chun Hu

    Full Text Available Changes in impedance between 24 hours and one month after cochlear implantation have never been explored due to the inability to switch on within one day. This study examined the effect of early activation (within 24 hours on the evolution of electrode impedance with the aim of providing information on the tissue-to-electrode interface when electrical stimulation was commenced one day post implantation.We performed a retrospective review at a single institution. Patients who received a Nucleus 24RECA implant system (Cochlear, Sydney, Australia and underwent initial switch-on within 24 hours postoperatively were included. Impedance measurements were obtained intraoperatively and postoperatively at 1 day, 1 week, 4 weeks, and 8 weeks.A significant drop in impedance was noted 1 day after an initial activation within 24 hours followed by a significant rise in impedance in all channels until 1 week, after which the impedance behaved differently in different segments. Basal and mid-portion electrodes revealed a slight increase while apical electrodes showed a slight decrease in impedance from 1 week to 8 weeks postoperatively. Impedance was relatively stable 4 weeks after surgery.This is the first study to report the evolution of impedance in all channels between initial mapping 1 day and 1 month after cochlear implantation. The underlying mechanism for the differences in behavior between different segments of the electrode may be associated with the combined effect of dynamics among the interplay of cell cover formation, electrical stimulation, and fibrotic reaction.

  10. A Generic Methodology for Superstructure Optimization of Different Processing Networks

    DEFF Research Database (Denmark)

    Bertran, Maria-Ona; Frauzem, Rebecca; Zhang, Lei

    2016-01-01

    In this paper, we propose a generic computer-aided methodology for synthesis of different processing networks using superstructure optimization. The methodology can handle different network optimization problems of various application fields. It integrates databases with a common data architecture......, a generic model to represent the processing steps, and appropriate optimization tools. A special software interface has been created to automate the steps in the methodology workflow, allow the transfer of data between tools and obtain the mathematical representation of the problem as required...

  11. Survival of various implant-supported prosthesis designs following 36 months of clinical function.

    Science.gov (United States)

    Rodriguez, A M; Orenstein, I H; Morris, H F; Ochi, S

    2000-12-01

    The use of endosseous dental implants to replace natural teeth lost to trauma, dental caries, or periodontal disease has become a predictable form of prosthetic treatment since gaining popularity in the early 1980s. While numerous clinical studies have focused on the survival of implants, few address the survival of different prosthesis designs. Beginning in 1991, 882 prostheses supported by more than 2,900 implants (687 patients) were placed by the Department of Veterans Affairs Dental Implant Clinical Research Group (DICRG). These prostheses were divided into five research strata based on arch location. The recommended design for each stratum was: bar-supported overdenture (maxillary completely edentulous); screw-retained hybrid denture (mandibular completely edentulous); screw-retained fixed partial denture (mandibular and maxillary posterior partially edentulous); and cemented single crown (maxillary anterior single tooth). Alternative overdenture designs were utilized in the edentulous arches when the recommended prosthesis could not be fabricated. Prosthesis success rates for the research strata were calculated for an observation time of up to 36 months following prosthesis placement. Success rates for the maxillary edentulous stratum ranged from 94.6% for the bar-retained overdenture supported by five to six fixtures to 81.8% for the cap-retained overdenture. The mandibular edentulous strata produced success rates of 98.1% for the fixed hybrid prosthesis to 91.7% for the cap-retained prosthesis. Success rates for maxillary and mandibular posterior fixed partial dentures were 94.3% and 92.6%, respectively, while the maxillary anterior single-tooth prosthesis yielded a success rate of 98.1% for the 36-month observation period. The recommended prosthesis designs investigated in this study proved to be reliable, with encouraging success rates for an observation period of 36 months following placement.

  12. Effects of framework design and layering material on fracture strength of implant-supported zirconia-based molar crowns.

    Science.gov (United States)

    Kamio, Shingo; Komine, Futoshi; Taguchi, Kohei; Iwasaki, Taro; Blatz, Markus B; Matsumura, Hideo

    2015-12-01

    To evaluate the effects of framework design and layering material on the fracture strength of implant-supported zirconia-based molar crowns. Sixty-six titanium abutments (GingiHue Post) were tightened onto dental implants (Implant Lab Analog). These abutment-implant complexes were randomly divided into three groups (n = 22) according to the design of the zirconia framework (Katana), namely, uniform-thickness (UNI), anatomic (ANA), and supported anatomic (SUP) designs. The specimens in each design group were further divided into two subgroups (n = 11): zirconia-based all-ceramic restorations (ZAC group) and zirconia-based restorations with an indirect composite material (Estenia C&B) layered onto the zirconia framework (ZIC group). All crowns were cemented on implant abutments, after which the specimens were tested for fracture resistance. The data were analyzed with the Kruskal-Wallis test and the Mann-Whitney U-test with the Bonferroni correction (α = 0.05). The following mean fracture strength values (kN) were obtained in UNI design, ANA design, and SUP design, respectively: Group ZAC, 3.78, 6.01, 6.50 and Group ZIC, 3.15, 5.65, 5.83. In both the ZAC and ZIC groups, fracture strength was significantly lower for the UNI design than the other two framework designs (P = 0.001). Fracture strength did not significantly differ (P > 0.420) between identical framework designs in the ZAC and ZIC groups. A framework design with standardized layer thickness and adequate support of veneer by zirconia frameworks, as in the ANA and SUP designs, increases fracture resistance in implant-supported zirconia-based restorations under conditions of chewing attrition. Indirect composite material and porcelain perform similarly as layering materials on zirconia frameworks. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. [Suggestions to strengthen quality management of herbal decoction pieces--based on production chain of herbal decoction pieces].

    Science.gov (United States)

    Liu, Yan; Nie, Qing; Chen, Jing

    2015-08-01

    With the development of society and the improvement of people's living standards, the effect of Chinese medicine in treatment and health care is more and more prominent. The herbal decoction pieces are the important part of Chinese medicine,it can be applied directly to clinical treatment and it's also the raw material of Chinese patent medicine. Therefore, the quality of herbal decoction pieces is quite important. The parts of the production of herbal decoction pieces are numerous, and there are possibilities of adverse effects on the quality of the herbal decoction pieces in every part. In this paper, we based on the production chain of herbal decoction pieces, analyzed the main problem that affect the quality of herbal decoction pieces in the part of selection of Chinese herbal medicines, planting, purchasing, processing, packaging, storage and transport, such as the poor quality of seed and seedlings of plant-based Chinese medicines, some plants left their place of origin and have been introduced in the place that is not suitable for this kind of plant, the insufficient growth time and the excessive harmful substances. The purchasers and the accepters lack of professional knowledge and professional ethics. The mechanism of processing is not clear, the standards can not be uniformed, and lack of qualified person in processing, etc. So we suggest: intensify the basic research of key scientific issues. Improve the quality of persons who work in herbal decoction pieces; Establish an "integration" mode of operation in herbal decoction pieces enterprise; Breeding high quality plant resources, establish the large-scale planting basement; Make the packing of herbal decoction pieces standard; Establish the modernization traditional Chinese medicine logistics enterprise.

  14. Implant-retained maxillary overdentures.

    Science.gov (United States)

    Eckert, Steven E; Carr, Alan B

    2004-07-01

    Overdentures supported by osseointegrated implants overcome many of the complications observed with overdentures supported by natural teeth. Dental implants are free of biologic consequences associated with natural teeth, such as dental caries and periodontal disease. Bone undercuts adjacent to implants do not mimic those found adjacent to natural tooth roots. Implants are used to provide predictable retention, support, and stability for overdenture prostheses. When lip or facial support is required, the overdenture is the treatment of choice. Likewise the overdenture may improve phonetic deficiencies associated with alveolar bone loss.

  15. Multiple piece turbine rotor blade

    Science.gov (United States)

    Jones, Russell B; Fedock, John A

    2013-05-21

    A multiple piece turbine rotor blade with a shell having an airfoil shape and secured between a spar and a platform with the spar including a tip end piece. a snap ring fits around the spar and abuts against the spar tip end piece on a top side and abuts against a shell on the bottom side so that the centrifugal loads from the shell is passed through the snap ring and into the spar and not through a tip cap dovetail slot and projection structure.

  16. Implant-Supported Telescopic Crown-Retained Overdentures for Oral Rehabilitation of Patients with Severe Bony Defects: A 5-Year Retrospective Study.

    Science.gov (United States)

    Zou, Duohong; Wang, Feng; Wu, Yiqun; Huang, Wei; Zhang, Chenping; Zhang, Zhiyuan

    2015-01-01

    To evaluate the performance of dental implant-supported telescopic crown (TC)-retained overdentures to restore the oral function of patients who have insufficient jawbone volume resulting from tumor resection or trauma. From January 2004 to December 2008, implant-supported TC-retained overdentures were used to restore the oral function of patients with severe bony defects resulting from tumor resection or trauma. Clinical data, including implant success and survival rates, biologic and mechanical complications, prosthodontic maintenance efforts, and patient satisfaction, were analyzed annually after delivery of the final prostheses. Twenty-four patients were treated, and a total of 88 implants were inserted to support TC-retained overdentures. The mean modified plaque index of implants remained low (76.3%) in the study showed the absence of bleeding on probing at follow-up visits. Peri-implant marginal bone loss (MBL) ranged from 0.8 to 1.2 mm. There was no statistically significant difference in the MBL between maxillary and mandibular implants (P = .43). The implant success rate was 100% after 5 years, and the prosthodontic maintenance and complication rate was 0.22 times per year. More than 90% of patients were satisfied with the restoration of their oral function using TCs. Based on our study of 24 patients treated with TC-retained overdentures, it appears that this treatment may be a viable option for patients with insufficient jawbone volume.

  17. Synthesis of noble metal nanoparticles and their superstructures; Darstellung von Edelmetallnanopartikeln und deren Ueberstrukturen

    Energy Technology Data Exchange (ETDEWEB)

    Bigall, Nadja-Carola

    2009-08-18

    A modified synthesis procedure for citrate-stabilized gold nanoparticles in aqueous solution is transferred under application of equal concentrations to the systems silver, platinum, and palladium. The nanoparticles are analyzed by means of absorption spectroscopy and electron microscopy. Ordered superstructures of the noble-metal nanoparticles can be synthesized by infiltration of templates of block-copolymer films with aqueous nanoparticle solution. In dependence on the pre-treatment of the polymer films either two-dimensional periodical arrangements with a periodicity of less than 30 nm or fingerprint-like arrangements with a groove distance in the same order of magnitude. By removal of the polymer one- respectively two-dimensional arrangements of platinum nanowires respectively nanoparticles on a silicon waver arise.

  18. Full mouth rehabilitation with retrievable metal-ceramic implant-supported fixed prostheses for a young patient with atrophic jaws: a clinical report.

    Science.gov (United States)

    Ameri, Narges; Alikhasi, Marzieh; Rezayani, Vida

    2017-09-01

    Treatment of atrophic edentulous jaws with implant-supported fixed prostheses is one of the most complicated challenges in dentistry. This clinical report describes the prosthesis which consists of screw retained frameworks with individual cement retained crowns which combines the advantages of the screw retained restoration with the advantage of cement retained.

  19. Single vs two implant-retained overdentures for edentulous mandibles: a systematic review.

    Science.gov (United States)

    Alqutaibi, Ahmed Yaseen; Esposito, Marco; Algabri, Radwan; Alfahad, Adnan; Kaddah, Amal; Farouk, Mohammed; Alsourori, Ali

    To compare prosthesis and implant failure, patient satisfaction, prosthetic complications and peri-implant marginal bone loss of mandibular overdentures (IOD) supported by a single or two implants. Manual and electronic database (PubMed and Cochrane) searches were performed to identify randomised controlled trials, without language restriction, comparing single vs two implant supported mandibular overdentures. Two investigators extracted data independently. The Cochrane tool was used for assessing the quality of included studies. Meta-analyses were performed for the included RCTs. Six publications corresponding to four RCTs were identified. Three RCTs (corresponding to five publications) were included and one trial was excluded. Follow-ups in function were 1, 3 and 5 years after loading. All included studies were considered to be at a high risk of bias. The pooled result revealed more prosthesis failures at overdentures supported by two implants at 1 year (three trials) (P = 0.02; Risk Difference: -0.12, 95% CI: -0.22, -0.02), however, there were non-significant differences at 3 years (two trials) (P = 0.22; Risk Difference: -0.32, 95% CI: -0.83, 0.19) and at 5 years (one trial) (P = 0.95; Risk Difference: 0.01, 95% CI: -0.22, 0.24). Regarding implant failures, there were more implant losses in overdentures supported by two implants at 1 year (three trials) (P = 0.02; Risk Difference: -0.12, 95% CI: -0.22, -0.02) and at 5 years (one trial) (P = 0.95; Risk Difference: -0.15, 95% CI: -0.28, -0.02), however, there were non-significant difference at 3 years (two trials) (P = 0.2; Risk Difference: -0.33, 95% CI: -0.84, 0.18). After 5 years in function, meta-analyses revealed that there were non-significant differences regarding overall prosthetic complications when mandibular overdentures supported by a single implant were compared with overdentures supported by two implants (P = 0.43; RD: 0.04, 95% CI: -0.06, 0.15). Mandibular overdentures retained by a single implant

  20. Comparative analysis of different joining techniques to improve the passive fit of cobalt-chromium superstructures.

    Science.gov (United States)

    Barbi, Francisco C L; Camarini, Edevaldo T; Silva, Rafael S; Endo, Eliana H; Pereira, Jefferson R

    2012-12-01

    The influence of different joining techniques on passive fit at the interface structure/abutment of cobalt-chromium (Co-Cr) superstructures has not yet been clearly established. The purpose of this study was to compare 3 different techniques of joining Co-Cr superstructures by measuring the resulting marginal misfit in a simulated prosthetic assembly. A specially designed metal model was used for casting, sectioning, joining, and measuring marginal misfit. Forty-five cast bar-type superstructures were fabricated in a Co-Cr alloy and randomly assigned by drawing lots to 3 groups (n=15) according to the joining method used: conventional gas-torch brazing (G-TB), laser welding (LW), and tungsten inert gas welding (TIG). Joined specimens were assembled onto abutment analogs in the metal model with the 1-screw method. The resulting marginal misfit was measured with scanning electron microscopy (SEM) at 3 different points: distal (D), central (C), and mesial (M) along the buccal aspect of both abutments: A (tightened) and B (without screw). The Levene test was used to evaluate variance homogeneity and then the Welsch ANOVA for heteroscedastic data (α=.05). Significant differences were found on abutment A between groups G-TB and LW (P=.013) measured mesially and between groups G-TB and TIG (P=.037) measured centrally. On abutment B, significant differences were found between groups G-TB and LW (Plaser method. Copyright © 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  1. All about alignment

    CERN Multimedia

    2006-01-01

    The ALICE absorbers, iron wall and superstructure have been installed with great precision. The ALICE front absorber, positioned in the centre of the detector, has been installed and aligned. Weighing more than 400 tonnes, the ALICE absorbers and the surrounding support structures have been installed and aligned with a precision of 1-2 mm, hardly an easy task but a very important one. The ALICE absorbers are made of three parts: the front absorber, a 35-tonne cone-shaped structure, and two small-angle absorbers, long straight cylinder sections weighing 18 and 40 tonnes. The three pieces lined up have a total length of about 17 m. In addition to these, ALICE technicians have installed a 300-tonne iron filter wall made of blocks that fit together like large Lego pieces and a surrounding metal support structure to hold the tracking and trigger chambers. The absorbers house the vacuum chamber and are also the reference surface for the positioning of the tracking and trigger chambers. For this reason, the ab...

  2. MR images of rupture and leakage of breast implants

    International Nuclear Information System (INIS)

    Fang Ling; Liu Pengcheng; Huang Rong; Hu Huaxin; Chen Zaizhong; Du Duanming; Liu Hanqiao; Feng Fei

    2002-01-01

    Objective: To investigate the diagnostic value of magnetic resonance imaging in detecting rupture and leakage of breast implants. Methods: Seventeen cases with breast implants were imaged by MR scanner. 1 normal silicone breast implant outside the body was scanned by MR as an consultative standard. MR images of silicone implants and polypropylene acyl amine implants were classified and analyzed. Results: In 7 cases, 12 single lumen silicone implants were intact, among them 8 were silicone gel-filled implants, 4 were physiological saline-filled implants. 2 physiological saline-filled implants ruptured, among them 1 belonged to intracapsular silicone implant rupture with subsided silicone gel capsule which presented as long T 1 signal and short T 2 signal on MR images; The other belonged to extracapsular silicone implant rapture with physiological saline granule outside breast on MR images. 20 breast implants in 10 cases were injected by polypropylene acyl amine, among them 2 breast implants were intact, 16 breast implants ruptured completely with pieces and nodes of long T 1 signal and long T 2 signal on MR images, 14 of 16 also presented polypropylene acyl amine granule outside breast; 2 breast implants splited inside with linguine sign. Conclusion: The magnetic resonance imaging can make clear the type and the seat of breast implants, the type of rupture of breast implants, and the distribution of leakage material. Therefore magnetic resonance imaging can be an effective guidance for clinical operation and can be an consultative standard for follow-up

  3. Clinical and radiological investigations of mandibular overdentures supported by conventional or mini-dental implants: A 2-year prospective follow-up study.

    Science.gov (United States)

    Temizel, Sonay; Heinemann, Friedhelm; Dirk, Cornelius; Bourauel, Christoph; Hasan, Istabrak

    2017-02-01

    Conventional dental implants are not applicable in the mandibular interforaminal region if bone volume is limited. Mini-dental implants offer an alternative means of supporting mandibular overdentures in a narrow residual ridge, without additional surgery. The purpose of this nonrandomized clinical trial was to compare the ability of mini-dental implants with that of conventional dental implants in supporting mandibular overdentures during a 2-year clinical follow-up. Bone quality, bone resorption, implant stability, and oral health were assessed radiographically. A total of 32 participants with edentulism were included. Twenty-two participants (99 implants) received 4 to 5 mini-dental implants (diameter: 1.8-2.4 mm; length: 13-15 mm, study group), and 10 participants (35 implants) received 2 to 4 conventional dental implants (diameter: 3.3-3.7 mm; length: 11-13 mm, control group). The selection of the participants in the study or control group was based on the available bone volume in the mandible. The selection was not randomized. The density of cortical bone thickness was measured in Hounsfield units (HU) from computed tomography data, and patients were followed for 2 years. The participants were examined 3, 6, 12, and 24 months after surgery. Primary stability immediately after the insertion of dental implants (Periotest), secondary stability 6 months after implantation, modified plaque, bleeding on probing indices, and probing depth were measured and analyzed statistically (α=.05). The mean HU value 6 months after implantation in the participants who received mini-dental implants was significantly (P=.035) higher (1250 HU) than that in the participants who received conventional dental implants (1100 HU). The probing depths around the conventional dental implants (1.6 and 1.8 mm, respectively) were significantly higher than those around the mini-dental implants (1.3 and 1.2 mm, respectively) 12 and 24 months after surgery, respectively (Pdental implants were

  4. Prosthetic outcome, patient complaints, and nutritional effects on elderly patients with magnet-retained, implant-supported overdentures--a 1-year report.

    Science.gov (United States)

    Khoo, Huan Ding; Chai, John; Chow, Tak Wah

    2013-01-01

    To study the changes in treatment outcomes of complete dentures and magnet-retained, implant-supported overdentures in a group of elderly patients. In this nonrandomized trial, 43 edentulous patients (14 men and 29 women) were fitted with complete dentures followed by implant-supported mandibular overdenture in a sequential model. Treatment outcomes used for analysis included objective assessment of denture quality (Woelfel's index), patient satisfaction, nutritional status, body mass index (BMI), and serum albumin level. The McNemar test was used to determine if significant differences in the Woelfel's index and nutritional status existed at different treatment phases. Repeated measures ANOVA and multiple pairwise comparison tests were used to analyze patient satisfaction. BMI status and serum albumin level at different treatment phases were analyzed with one-way ANOVA and Tukey post hoc test. At the 1-year follow-up, significant improvements were recorded for the objective assessment of denture quality and patient complaints (P .05) CONCLUSIONS: The present study demonstrated that in elderly patients with stable health and nutritional status, complete dentures made in a university clinic brought about overall improvement in denture quality and reduction in denture complaint score. Insertion of mandibular implant-supported overdentures further improved the mandibular denture quality and reduced the mandibular denture complaint score. In this group of patients, no improvement in BMI, serum albumin value, and nutritional status were documented.

  5. Accuracy of digital impression in dental implants: A literature review

    OpenAIRE

    Sudabe Kulivand; Maryam Moslemion

    2016-01-01

    Restoration of dental implants remains one of the most challenging aspects of implant dentistry. Although it is not clear whether prosthetic misfit could affect osseointegration, mechanical complications of implant-supported prostheses can be avoided by achieving a good passive fit between the framework and the implants. Passive fit is a difficult concept to define. Obtaining absolute passive fit of the prosthetic framework on implants has been reported to be nearly impossible. Because of ...

  6. Analysis of load distribution in tooth-implant supported fixed partial dentures by the use of resilient abutment.

    Science.gov (United States)

    Glisić, Mirko; Stamenković, Dragoslav; Grbović, Aleksandar; Todorović, Aleksandar; Marković, Aleksa; Trifković, Branka

    2016-01-01

    Differences between the tooth and implant response to load can lead to many biological and technical implications in the conditions of occlusal forces. The objective of this study was to analyze load distribution in tooth/implant-supported fixed partial dentures with the use of resilient TSA (Titan Shock Absorber, BoneCare GmbH, Augsburg, Germany) abutment and conventional non-resilient abutment using finite element method. This study presents two basic 3D models. For one model a standard non-resilient abutment is used, and on the implant of the second model a resilient TSA abutment is applied. The virtual model contains drawn contours of tooth, mucous membranes, implant, cortical bones and spongiosa, abutment and suprastructure. The experiment used 500 N of vertical force, applied in three different cases of axial load. Calculations of von Mises equivalent stresses of the tooth root and periodontium, implants and peri-implant tissue were made. For the model to which a non-resilient abutment is applied, maximum stress values in all three cases are observed in the cortical part of the bone (maximum stress value of 49.7 MPa). Measurements of stress and deformation in the bone tissue in the model with application of the resilientTSA abutment demonstrated similar distribution; however, these values are many times lower than in the model with non-resilient TSA abutment (maximum stress value of 28.9 MPa). Application of the resilient TSA abutment results in more equal distribution of stress and deformations in the bone tissue under vertical forces. These values are many times lower than in the model with the non-resilient abutment.

  7. Influence of Abutment Angle on Implant Strain When Supporting a Distal Extension Removable Partial Dental Prosthesis: An In Vitro Study.

    Science.gov (United States)

    Hirata, Kiyotaka; Takahashi, Toshihito; Tomita, Akiko; Gonda, Tomoya; Maeda, Yoshinobu

    This study evaluated the impact of angled abutments on strain in implants supporting a distal extension removable partial denture. An in vitro model of an implant supporting a distal extension removable partial denture was developed. The implant was positioned with a 17- or 30-degree mesial inclination, with either a healing abutment or a corrective multiunit abutment. Levels of strain under load were compared, and the results were compared using t test (P = .05). Correcting angulation with a multiunit angled abutment significantly decreased strain (P abutment. An angled abutment decreased the strain on an inclined implant significantly more than a healing abutment when loaded under a distal extension removable partial denture.

  8. Centering and alignment device of a fuel assembling under a heart upper sheet of a pressure water nuclear reactor and centering piece replacement process

    International Nuclear Information System (INIS)

    Bougis, J.C.

    1994-01-01

    The crossing opening of the heart upper sheet contains a central part and two end parts of which diameter is higher than the central part one. The centering piece contains a head putting down, thanks to a support part, on a retaining of the opening, a centering and positioning smooth part and a threaded part. The device also contains a nut screwed on the threaded part of the centering piece so far as to come supporting on a retaining of the opening. The nut is made not unscrewed thanks to a stopping washer soldered inside the end part of the crossing opening. (Author). 3 figs., 5 refs

  9. La traducción de la onomatopeya en el manga One Piece : tipología y técnicas

    OpenAIRE

    Pérez Álvaro, Laura

    2017-01-01

    Treball Final de Grau en Traducció i Interpretació. Codi: TI0983. Curs: 2015/2016 Este trabajo es un estudio de caso de la traducción de las onomatopeyas en el primer tomo del manga One Piece (Eiichiro Oda). El objetivo que se persigue con esta investigación es comprobar si la posición de las onomatopeyas en diferentes lugares de las páginas de un cómic, es decir, dentro o fuera de bocadillo de diálogo, influye en el método de traducción empleado. Los métodos que se incluyen...

  10. Fatigue induced changes in conical implant-abutment connections.

    Science.gov (United States)

    Blum, Kai; Wiest, Wolfram; Fella, Christian; Balles, Andreas; Dittmann, Jonas; Rack, Alexander; Maier, Dominik; Thomann, Ralf; Spies, Benedikt Christopher; Kohal, Ralf Joachim; Zabler, Simon; Nelson, Katja

    2015-11-01

    Based on the current lack of data and understanding of the wear behavior of dental two-piece implants, this study aims for evaluating the microgap formation and wear pattern of different implants in the course of cyclic loading. Several implant systems with different conical implant-abutment interfaces were purchased. The implants were first evaluated using synchrotron X-ray high-resolution radiography (SRX) and scanning electron microscopy (SEM). The implant-abutment assemblies were then subjected to cyclic loading at 98N and their microgap was evaluated after 100,000, 200,000 and 1 million cycles using SRX, synchrotron micro-tomography (μCT). Wear mechanisms of the implant-abutment connection (IAC) after 200,000 cycles and 1 million cycles were further characterized using SEM. All implants exhibit a microgap between the implant and abutment prior to loading. The gap size increased with cyclic loading with its changes being significantly higher within the first 200,000 cycles. Wear was seen in all implants regardless of their interface design. The wear pattern comprised adhesive wear and fretting. Wear behavior changed when a different mounting medium was used (brass vs. polymer). A micromotion of the abutment during cyclic loading can induce wear and wear particles in conical dental implant systems. This feature accompanied with the formation of a microgap at the IAC is highly relevant for the longevity of the implants. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  11. Maxillary implant-supported overdentures opposed by (partial) natural dentitions: a 5-year prospective case series study.

    Science.gov (United States)

    Boven, G C; Slot, J W A; Raghoebar, G M; Vissink, A; Meijer, H J A

    2017-12-01

    The aim of this study was to assess the 5-year treatment outcome of maxillary implant-retained overdentures opposed by natural antagonistic teeth. Fifty consecutive patients received maxillary overdentures supported by six dental implants. Implants were placed in the anterior region, if enough bone was present (n = 25 patients) Implant were placed in the posterior region if implant placement in the anterior region was not possible (n = 25 patients). Variables assessed included survival of implants, condition of hard and soft peri-implant tissues and patients' satisfaction. The five-year implant survival rate was 97·0% and 99·3%, and mean radiographic bone loss was 0·23 and 0·69 mm in the anterior and posterior group, respectively. Median scores for plaque, calculus, gingiva, bleeding and mean scores for pocket probing depth were low and stayed low. Patients' satisfaction after treatment was high in both groups. Within the limits of this 5-year study, it is concluded that six dental implants (placed in the anterior or posterior region) connected with a bar and opposed to natural antagonistic teeth result in acceptable results for clinical parameters and good outcomes for marginal bone level changes and patient satisfaction. © 2017 John Wiley & Sons Ltd.

  12. A three-dimensional finite element analysis for overdenture attachments supported by teeth and/or mini dental implants.

    Science.gov (United States)

    Fatalla, Abdalbseet A; Song, Ke; Du, Tianfeng; Cao, Yingguang

    2012-12-01

    The aim of this study was to establish the optimum design and attachment combination to support an overdenture with minimal stress and flexing produced in the alveolar bone surrounding any natural teeth and/or mini dental implants. Twelve models were included in the study: the six main models (A, B, C, D, E, and F) were categorized according to the support designs of the overdenture prosthesis, and each model was further subdivided according to the attachment combinations into model 1: with Dalbo elliptic and/or O-ring attachments only and model 2: with flexible acrylic attachments. Vertical loads (35 N) and 17.5 N lateral loads under static conditions were applied to the models to simulate the occlusal forces following the concept of lingualized occlusion. All conditions were created using a finite element software program. Maximum von Mises stress at the level of the attachments and at the bone support foundation interfaces were compared in all 12 models. The flexing of the mandible and the attachments were also compared qualitatively. Stress on these models was analyzed after the given loading condition. The results showed that the model with three freestanding mini dental implants and flexible acrylic attachments showed the lowest von Mises stress and flexing, while the models with four freestanding mini dental implants and O-ring attachments showed the highest von Mises stress. Three freestanding mini dental implants with flexible acrylic attachment systems supporting an overdenture were better choices than four mini dental implants with O-ring attachment systems, which showed the maximum flexing and stress values in this qualitative comparison. © 2012 by the American College of Prosthodontists.

  13. Case study: highly loaded MSE bridge supporting structure, Syncrude NMAPS conveyor overpasses

    Energy Technology Data Exchange (ETDEWEB)

    Scherger, B.; Brockbank, B. [Reinforced Earth Company Ltd., Edmonton, AB (Canada); Mimura, W. [Syncrude Canada Ltd., Edmonton, AB (Canada)

    2005-07-01

    A crusher and conveyor system was constructed at the Mildred Lake Oil Sands Mine near Fort McMurray, Alberta in order to facilitate ore delivery from Syncrude's North Mine. As part of this North Mine Auxiliary Production System (NMAPS), Syncrude Canada and their consultant Cosyn Technology identified the need for 3 overpasses over conveyors in the North Mine in order to provide unrestricted crossing over the operating conveyor system for the heavy hauler trucks and light vehicle mine traffic. The overpasses were designed to support the dead load of the granular fill and the live load of two loaded heavy hauler trucks, with a design load for each loaded hauler of 670 900 kg. This paper reviewed various aspects of the design from planning, structure selection, and overall stability and bearing capacity considerations. The different designs in the 3 new overpasses accommodated foundation and loading requirements. The designs ranged from the use of precast one-piece reinforced concrete arches, Mechanically Stabilized Earth (MSE) bridge abutment technology, and a combination of the two. The MSE retaining walls directly supported the bridge superstructure without the use of piles or other deep structural foundations. The design was challenging because of the significant vertical stresses transferred onto the wall. All 3 overpasses also used MSE walls for the supporting end wing walls. The main focus of this paper was on the heavily loaded MSE walls supporting the bridge abutment style overpasses. This structure has illustrated the capability of properly designed MSE wall structures with steel soil reinforcement and reinforced precast concrete face panels to successfully carry bridge footing pressure loadings up to 545 kPa. It was concluded that this case has good potential for use in future bridge projects in both the industrial and highway sectors. 2 refs., 7 figs.

  14. Nb2OsB2, with a new twofold superstructure of the U3Si2 type: Synthesis, crystal chemistry and chemical bonding

    International Nuclear Information System (INIS)

    Mbarki, Mohammed; Touzani, Rachid St.; Fokwa, Boniface P.T.

    2013-01-01

    The new ternary metal-rich boride, Nb 2 OsB 2 , was synthesized by arc-melting the elements in a water-cooled copper crucible under an argon atmosphere. The compound was characterized from single-crystal X-ray data and EDX measurements. It crystallizes as a new superstructure (space group P4/mnc, no. 128) of the tetragonal U 3 Si 2 -structure type with lattice parameters a=5.922(1) Å and c=6.879(2) Å. All of the B atoms are involved in B 2 dumbbells with B–B distances of 1.89(4) Å. Structure relaxation using VASP (Vienna ab intio Simulation Package) has confirmed the space group and the lattice parameters. According to electronic structure calculations (TB–LMTO–ASA), the homoatomic B–B interactions are optimized and very strong, but relatively strong heteroatomic Os–B, Nb–B and Nb–Os bonds are also found: These interactions, which together build a three-dimensional network, are mainly responsible for the structural stability of this new phase. The density of state at the Fermi level predicts metallic behavior, as expected, from this metal-rich boride. - Graphical abstract: Nb 2 OsB 2 is, to the best of our knowledge, the first fully characterized phase in the ternary Nb–Os–B system. It crystallizes (space group P4/mnc, 128) with a new twofold superstructure of the U 3 Si 2 structure type (space group P4/mbm, 127), and is therefore the first boride in this structure family crystallizing with a superstructure of the U 3 Si 2 structure type. We show that the distortions leading to this superstructure occurs mainly in the Nb-layer, which tries to accommodate the large osmium atoms. The consequence of this puckering is the building osmium dumbbells instead of chains along [001]. - Highlights: • First compound in the Nb–Os–B system. • New twofold superstructure of U 3 Si 2 structure type. • Puckering of Nb-layer responsible for superstructure occurrence. • Chemical bonding studied by density functional theory

  15. Arthroplasty knee registry of Catalonia: What scientific evidence supports the implantation of our prosthesis?

    Science.gov (United States)

    Samaniego Alonso, R; Gaviria Parada, E; Pons Cabrafiga, M; Espallargues Carreras, M; Martinez Cruz, O

    2018-02-28

    In our environment, it is increasingly necessary to perform an activity based on scientific evidence and the field of prosthetic surgery should be governed by the same principles. The national arthroplasty registries allow us to obtain a large amount of data in order to evaluate this technique. The aim of our study is to analyse the scientific evidence that supports the primary total knee arthroplasties implanted in Catalonian public hospitals, based on the Arthoplasty Registry of Catalonia (RACat) MATERIAL AND METHODS: A review of the literature was carried out on knee prostheses (cruciate retaining, posterior stabilized, constricted and rotational) recorded in RACat between the period 2005-2013 in the following databases: Orthopedic Data Evaluation Panel, PubMed, TripDatabase and Google Scholar. The prostheses implanted in fewer than 10 units (1,358 prostheses corresponding to 62 models) were excluded. 41,947 prostheses (96.86%) were analysed out of 43,305 implanted, corresponding to 74 different models. In 13 models (n = 4,715) (11.24%) no clinical evidence to support their use was found. In the remaining 36 models (n = 13,609) (32.45%), level iv studies were the most predominant evidence. There was a significant number of implanted prostheses (11.24%) for which no clinical evidence was found. The number of models should be noted, 36 out of 110, with fewer than 10 units implanted. The use of arthroplasty registries has proved an extremely useful tool that allows us to analyse and draw conclusions in order to improve the efficiency of this surgical technique. Copyright © 2018 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Influence of Manufacturing Methods of Implant-Supported Crowns on External and Internal Marginal Fit: A Micro-CT Analysis.

    Science.gov (United States)

    Moris, Izabela C M; Monteiro, Silas Borges; Martins, Raíssa; Ribeiro, Ricardo Faria; Gomes, Erica A

    2018-01-01

    To evaluate the influence of different manufacturing methods of single implant-supported metallic crowns on the internal and external marginal fit through computed microtomography. Forty external hexagon implants were divided into 4 groups ( n = 8), according to the manufacturing method: GC, conventional casting; GI, induction casting; GP, plasma casting; and GCAD, CAD/CAM machining. The crowns were attached to the implants with insertion torque of 30 N·cm. The external (vertical and horizontal) marginal fit and internal fit were assessed through computed microtomography. Internal and external marginal fit data ( μ m) were submitted to a one-way ANOVA and Tukey's test ( α = .05). Qualitative evaluation of the images was conducted by using micro-CT. The statistical analysis revealed no significant difference between the groups for vertical misfit ( P = 0.721). There was no significant difference ( P > 0.05) for the internal and horizontal marginal misfit in the groups GC, GI, and GP, but it was found for the group GCAD ( P ≤ 0.05). Qualitative analysis revealed that most of the samples of cast groups exhibited crowns underextension while the group GCAD showed overextension. The manufacturing method of the crowns influenced the accuracy of marginal fit between the prosthesis and implant. The best results were found for the crowns fabricated through CAD/CAM machining.

  17. Comparative three-dimensional finite element analysis of implant-supported fixed complete arch mandibular prostheses in two materials.

    Science.gov (United States)

    Tribst, João Paulo Mendes; de Morais, Dayana Campanelli; Alonso, Alexandre Abhdala; Piva, Amanda Maria de Oliveira Dal; Borges, Alexandre Luis Souto

    2017-01-01

    The increase of requests for implant-supported prosthesis (ISP) with zirconia as infrastructure has attracted a lot of attention due to its esthetics, biocompatibility, and survival rate similar to metallic infrastructure. The aim of this study was to evaluate the influence of two different framework materials on stress distribution over a bone tissue-simulating material. Two ISP were modeled and divided into two infrastructure materials: titanium (Ti) and zirconia. Then, these bars were attached to a modeled jaw with polyurethane properties to simulate bone tissue. An axial load of 200 N was applied on a standardized area for both systems. Maximum principal stress (MPS) on solids and microstrain (MS) generated through the jaw were analyzed by finite element analysis. According to MS, both models showed strains on peri-implant region of the penultimate (same side of the load application) and central implants. For MPS, more stress concentration was slightly higher in the left posterior region for Ti's bar. In prosthetic fixation screws, the MPS prevailed strongly in Ti protocol, while for zirconia's bar, the cervical of the penultimate implant was the one that highlighted larger areas of possible damages. The stress generated in all constituents of the system was not significantly influenced by the framework's material. This allows suggesting that in cases without components, the use of a framework in zirconia has biomechanical behavior similar to that of a Ti bar.

  18. Periodontal ligament influence on the stress distribution in a removable partial denture supported by implant: a finite element analysis

    Directory of Open Access Journals (Sweden)

    Carlos Marcelo Archangelo

    2012-06-01

    Full Text Available OBJECTIVES: The non-homogenous aspect of periodontal ligament (PDL has been examined using finite element analysis (FEA to better simulate PDL behavior. The aim of this study was to assess, by 2-D FEA, the influence of non-homogenous PDL on the stress distribution when the free-end saddle removable partial denture (RPD is partially supported by an osseointegrated implant. MATERIAL AND METHODS: Six finite element (FE models of a partially edentulous mandible were created to represent two types of PDL (non-homogenous and homogenous and two types of RPD (conventional RPD, supported by tooth and fibromucosa; and modified RPD, supported by tooth and implant [10.00x3.75 mm]. Two additional Fe models without RPD were used as control models. The non-homogenous PDL was modeled using beam elements to simulate the crest, horizontal, oblique and apical fibers. The load (50 N was applied in each cusp simultaneously. Regarding boundary conditions the border of alveolar ridge was fixed along the x axis. The FE software (Ansys 10.0 was used to compute the stress fields, and the von Mises stress criterion (svM was applied to analyze the results. RESULTS: The peak of svM in non-homogenous PDL was higher than that for the homogenous condition. The benefits of implants were enhanced for the non-homogenous PDL condition, with drastic svM reduction on the posterior half of the alveolar ridge. The implant did not reduce the stress on the support tooth for both PDL conditions. Conclusion: The PDL modeled in the non-homogeneous form increased the benefits of the osseointegrated implant in comparison with the homogeneous condition. Using the non-homogenous PDL, the presence of osseointegrated implant did not reduce the stress on the supporting tooth.

  19. Implant-supported mandibular overdentures retained with ball or bar attachments: a randomized prospective 5-year study

    DEFF Research Database (Denmark)

    Gotfredsen, K; Holm, B

    2001-01-01

    PURPOSE: The aim of the present study was to evaluate the periimplant conditions and the maintenance requirements for implant-supported overdentures in the mandible retained with ball or bar attachments during a 5-year period. MATERIALS AND METHODS: Twenty-six completely edentulous patients had two...... differences were registered. The mean frequency of complications/repairs per patient per year was 1.0 in the bar group and 0.6 in the ball group during the 5-year observation period. CONCLUSION: Two implants with ball or bar attachment supported an overdenture in the mandible for 5 years with a 100% survival...

  20. Clinical experiences with laser-welded titanium frameworks supported by implants in the edentulous mandible: a 5-year follow-up study.

    Science.gov (United States)

    Ortorp, A; Linden, B; Jemt, T

    1999-01-01

    The purpose of this study was to report the 5-year clinical performance of implant-supported prostheses with laser-welded titanium frameworks and to compare their performance with that of prostheses provided with conventional cast frameworks. On a routine basis, a consecutive group of 824 edentulous patients were provided with fixed prostheses supported by implants in the edentulous mandible. In addition to conventional gold-alloy castings, patients were at random provided with 2 kinds of laser-welded titanium frameworks. In all, 155 patients were included in the 2 titanium framework groups. A control group of 53 randomly selected patients with conventional gold-alloy castings was used for comparison. Clinical and radiographic 5-year data was collected for the 3 groups. All followed patients still had fixed prostheses in the mandible after 5 years. The overall cumulative success rates were 95.9% and 99.7% for titanium-framework prostheses and implants, respectively. The corresponding success rates for the control group were 100% and 99.6%, respectively. Bone loss was 0.5 mm on average during the 5-year follow-up period. The most common complications for titanium frameworks were resin or tooth fractures, gingival inflammation, and fractures of the metal frames (10%). One of the cast frameworks fractured and was resoldered. Loose and fractured implant screw components were few (laser-welded titanium frameworks seem to be a viable alternative to conventional castings in the edentulous mandible.

  1. A simple procedure for retrieval of a cement-retained implant-supported crown: a case report.

    Science.gov (United States)

    Buzayan, Muaiyed Mahmoud; Mahmood, Wan Adida; Yunus, Norsiah Binti

    2014-02-01

    Retrieval of cement-retained implant prostheses can be more demanding than retrieval of screw-retained prostheses. This case report describes a simple and predictable procedure to locate the abutment screw access openings of cementretained implant-supported crowns in cases of fractured ceramic veneer. A conventional periapical radiography image was captured using a digital camera, transferred to a computer, and manipulated using Microsoft Word document software to estimate the location of the abutment screw access.

  2. Rehabilitation of resorbed mandibular ridges using mini implant retained overdentures: A case series with 3 year follow-up

    Directory of Open Access Journals (Sweden)

    Pooja Kumari

    2016-01-01

    Full Text Available With the increasing average life expectancy of human beings, the need to cater geriatric patients is ever increasing. Complete dentures are an indispensable tool in this regard. The loose and unstable lower complete denture owing to residual ridge resorption is one of the most common problems faced by edentulous patients. Dental implant retained overdentures have emerged as an efficient treatment modality for such patients. Though useful, not every patient is a suitable candidate to go for conventional implant-borne prosthesis, limitation being the available bone width. In such cases, mini implants may be used for augmenting the retention of the dentures and improving the quality of life of patients. In this case series, rehabilitation of three compromised cases with mini implant retained overdentures have been described wherein patients are experiencing instability of lower denture due to thin resorbed mandibular ridges. In one of the cases, three mini implants placed in A, C, and E position were splinted using a cemented bar to retain the mandibular denture. The other two cases were rehabilitated using unsplinted ball type one piece mini implants placed in A, C, and E position in one case and B and D position in another case. Though splinted bar design should be preferred but the lack of available vertical space precluded the utilization of bar in other two cases. The results were found to be satisfactory with no complications reported during a follow-up period of over 3 years in all the cases.

  3. Retropupillary iris claw intraocular lens implantation in aphakia for dislocated intraocular lens

    Directory of Open Access Journals (Sweden)

    Faria MY

    2016-08-01

    Full Text Available Mun Yueh Faria,1–3 Nuno Pinto Ferreira,1–3 Joana Medeiros Pinto,1–3 David Cordeiro Sousa,1–3 Ines Leal,1–3 Eliana Neto,1–3 Carlos Marques-Neves1–3 1Centro de Estudos da Visão, Universidade de Lisboa, 2Department of Ophthalmology, Hospital de Santa Maria, 3Faculty of Medicine, University of Lisbon, Lisbon, Portugal Background: Nowadays, dislocated intraocular lenses (IOLs and inadequate capsular support are becoming a challenge for every ophthalmic surgeon. Explantation of dislocated IOL and iris claw IOL (ICIOL are the techniques that have been used in our ophthalmic department. The aim of this study is to report our technique for retropupillar ICIOL.Methods: This study is a retrospective case series. A total of 105 eyes with dislocated IOL from the patients at the Department of Ophthalmology in Santa Maria Hospital, a tertiary reference hospital in Lisbon, Portugal, from January 2012 until January 2016, had been analyzed. Of these 105 eyes, 66 eyes had dislocated one-piece IOL and 39 eyes had dislocated three-piece IOL. The latter underwent iris suture of the same IOL and were excluded from this study. The remaining 66 eyes with dislocated one-piece IOL underwent pars plana vitrectomy, that is, explantation of dislocated IOL through corneal incision and an implantation of retropupillary ICIOL. Operative data and postoperative outcomes included best corrected visual acuity, IOL position, intraocular pressure, pigment dispersion, clinical signs of endothelial cell loss, and anterior chamber depth.Results: The mean follow-up was 23 months (range: 6–48 months. The mean preoperative best corrected visual acuity was 1.260±0.771 logMAR, and postoperative best corrected visual acuity was 0.352±0.400 logMAR units. Mean vision gain was 0.909 logMar units. The patients had the following complications: 1 retinal detachment was found in one patient, 2 corneal edema was found in three patients, 3 high intraocular pressure was observed in

  4. Push piece for spent fuel elements magazine

    International Nuclear Information System (INIS)

    Griveau, R.; Kerlau, D.; Tucoulat, D.; Colas, J.; Pellier, R.

    1989-01-01

    The push piece permits the displacement of little section elements in a magazine of high section. At the end of cut, the push piece leans its flank against an auxiliary blank holder and the element is pushed by a paddle, the push piece being immobilized [fr

  5. The influence of screw type, alloy and cylinder position on the marginal fit of implant frameworks before and after laser welding.

    Science.gov (United States)

    Castilio, Daniela; Pedreira, Ana Paula Ribeiro do Vale; Rossetti, Paulo Henrique Orlato; Rossetti, Leylha Maria Nunes; Bonachela, Wellington Cardoso

    2006-04-01

    Misfit at the abutment-prosthetic cylinder interface can cause loss of preload, leading to loosening or fracture of gold and titanium screws. To evaluate the influence of screw type, alloy, and cylinder position on marginal fit of implant frameworks before and after laser welding. After Estheticone-like abutments were screwed to the implants, thirty plastic prosthetic cylinders were mounted and waxed-up to fifteen cylindrical bars. Each specimen had three interconnected prosthetic components. Five specimens were one-piece cast in titanium and five in cobalt-chromium alloy. On each specimen, tests were conducted with hexagonal titanium and slotted gold screws separately, performing a total of thirty tested screws. Measurements at the interfaces were performed using an optical microscope with 5mm accuracy. After sectioning, specimens were laser welded and new measurements were obtained. Data were submitted to a four-way ANOVA and Tukey's multiple comparisons test (alpha=0.05). Slotted and hexagonal screws did not present significant differences regarding to the fit of cylinders cast in titanium, either in one-piece casting framework or after laser welding. When slotted and hexagonal screws were tested on the cobalt-chromium specimens, statistically significant differences were found for the one-piece casting condition, with the slotted screws presenting better fit (24.13 microm) than the hexagonal screws (27.93 microm). Besides, no statistically significant differences were found after laser welding. 1) The use of different metal alloys do exert influence on the marginal fit, 2) The slotted and hexagonal screws play the exclusive role of fixing the prosthesis, and did not improve the fit of cylinders, and 3) cylinder position did not affect marginal fit values.

  6. Individuality in harpsichord performance: disentangling performer- and piece-specific influences on interpretive choices.

    Science.gov (United States)

    Gingras, Bruno; Asselin, Pierre-Yves; McAdams, Stephen

    2013-01-01

    Although a growing body of research has examined issues related to individuality in music performance, few studies have attempted to quantify markers of individuality that transcend pieces and musical styles. This study aims to identify such meta-markers by discriminating between influences linked to specific pieces or interpretive goals and performer-specific playing styles, using two complementary statistical approaches: linear mixed models (LMMs) to estimate fixed (piece and interpretation) and random (performer) effects, and similarity analyses to compare expressive profiles on a note-by-note basis across pieces and expressive parameters. Twelve professional harpsichordists recorded three pieces representative of the Baroque harpsichord repertoire, including three interpretations of one of these pieces, each emphasizing a different melodic line, on an instrument equipped with a MIDI console. Four expressive parameters were analyzed: articulation, note onset asynchrony, timing, and velocity. LMMs showed that piece-specific influences were much larger for articulation than for other parameters, for which performer-specific effects were predominant, and that piece-specific influences were generally larger than effects associated with interpretive goals. Some performers consistently deviated from the mean values for articulation and velocity across pieces and interpretations, suggesting that global measures of expressivity may in some cases constitute valid markers of artistic individuality. Similarity analyses detected significant associations among the magnitudes of the correlations between the expressive profiles of different performers. These associations were found both when comparing across parameters and within the same piece or interpretation, or on the same parameter and across pieces or interpretations. These findings suggest the existence of expressive meta-strategies that can manifest themselves across pieces, interpretive goals, or expressive devices.

  7. Individuality in harpsichord performance: Disentangling performer- and piece-specific influences on interpretive choices

    Directory of Open Access Journals (Sweden)

    Bruno eGingras

    2013-11-01

    Full Text Available Although a growing body of research has examined issues related to individuality in music performance, few studies have attempted to quantify markers of individuality that transcend pieces and musical styles. This study aims to identify such meta-markers by discriminating between influences linked to specific pieces or interpretive goals and performer-specific playing styles, using two complementary statistical approaches: linear mixed models (LMMs to estimate fixed (piece and interpretation and random (performer effects, and similarity analyses to compare expressive profiles on a note-by-note basis across pieces and expressive parameters. Twelve professional harpsichordists recorded three pieces representative of the Baroque harpsichord repertoire, including three interpretations of one of these pieces, each emphasizing a different melodic line, on an instrument equipped with a MIDI console. Four expressive parameters were analyzed: articulation, note onset asynchrony, timing, and velocity. LMMs showed that piece-specific influences were much larger for articulation than for other parameters, for which performer-specific effects were predominant, and that piece-specific influences were generally larger than effects associated with interpretive goals. Some performers consistently deviated from the mean values for articulation and velocity across pieces and interpretations, suggesting that global measures of expressivity may in some cases constitute valid markers of artistic individuality. Similarity analyses detected significant associations among the magnitudes of the correlations between the expressive profiles of different performers. These associations were found both when comparing across parameters and within the same piece or interpretation, or on the same parameter and across pieces or interpretations. These findings suggest the existence of expressive meta-strategies that can manifest themselves across pieces, interpretive goals, or

  8. Devoluming and stabilizing method for end piece

    International Nuclear Information System (INIS)

    Ikeda, Satoshi; Shiotsuki, Msao; Kawamura, Shigeyoshi; Komatsu, Fumiaki.

    1991-01-01

    As a first method, end pieces and other radioactive metal wastes are filled as a mixture in a vessel, and preliminary compression is conducted. Then, the bulk density of the radioactive metal wastes is reduced and gaps in the end pieces are filled with radioactive metal wastes. If they are applied with heat treatment under high pressure in this state together with the vessel, they are devolumed and stabilized without damaging the vessel. As a second method, metal powders are mixed and filled in the vessel together with the end pieces. The gaps in the end pieces are filled with the metal powders and if they are applied with heat treatment under high pressure in this state together with the vessel, the end pieces are devolumed and stabilized without damaging the vessel in the same manner. This can devolume and stabilize the end pieces separated from nuclear fuel assemblies easily and safely. (T.M.)

  9. Dichotic Listening Can Improve Perceived Clarity of Music in Cochlear Implant Users

    DEFF Research Database (Denmark)

    Vannson, Nicolas; Innes-Brown, Hamish; Marozeau, Jeremy

    2015-01-01

    Musical enjoyment for cochlear implant (CI) recipients is often reported to be unsatisfactory. Our goal was to determine whether the musical experience of postlingually deafened adult CI recipients could be enriched by presenting the bass and treble clef parts of short polyphonic piano pieces...

  10. Electromyographic evaluation of mastication and swallowing in elderly individuals with mandibular fixed implant-supported prostheses

    Directory of Open Access Journals (Sweden)

    Giédre Berretin-Felix

    2008-04-01

    Full Text Available This study evaluated the effect of implant-supported oral rehabilitation in the mandible on the electromyographic activity during mastication and swallowing in edentulous elderly individuals. Fifteen patients aged more than 60 years were evaluated, being 10 females and 5 males. All patients were edentulous, wore removable complete dentures on both dental arches, and had the mandibular dentures replaced by implant-supported prostheses. All patients were submitted to electromyographic evaluation of the masseter, superior orbicularis oris muscles, and the submental muscles, before surgery and 3, 6 and 18 months postoperatively, using foods of different textures. The results obtained at the different periods were analyzed statistically by Kruskal-Wallis non-parametric test. Statistical analysis showed that only the masseter muscle had a significant loss in electromyographic activity (p<0.001, with a tendency of similar response for the submental muscles. Moreover, there was an increase in the activity of the orbicularis oris muscle during rubber chewing after treatment, yet without statistically significant difference. Mandibular fixed implant-supported prostheses in elderly individuals revealed a decrease in electromyographic amplitude for the masseter muscles during swallowing, which may indicate adaptation to new conditions of stability provided by fixation of the complete denture in the mandibular arch.

  11. Electromyographic evaluation of implant-supported prostheses in hemimandibulectomy-reconstructed patients.

    Science.gov (United States)

    Dellavia, Claudia; Romeo, Eugenio; Ghisolfi, Marco; Chiapasco, Matteo; Sforza, Chiarella; Ferrario, Virgilio F

    2007-06-01

    To assess the clinical conditions, patient's satisfaction and functional outcomes in oral neoplasia patients with hemimandibulectomy, bone reconstruction and implant-supported prosthesis. Twelve patients after mandibular resection (with and without condyle), reconstruction and successful fixed implant-supported prosthesis rehabilitation were examined. Patients underwent clinical evaluation and filled in a questionnaire about their satisfaction toward oral functions. Surface electromyography (EMG) of the masticatory muscles was performed during a 15-s unilateral gum chewing test. EMG potentials were standardized as percentage of a maximum clench on cotton rolls and compared with reference data obtained from 20 healthy subjects. Excellent clinical and radiological parameters were found. Patients stated a decreased post-rehabilitation satisfaction toward mastication and phonetics, but an increased attention to oral care. Only patients with condylar resection reported augmented esthetic scores. In both the resected and the remaining sides, chewing frequency was higher in the patients than in the reference group (Wilcoxon's rank-sum test, Pchewing were more variable in the reconstructed patients than in control subjects; the difference was significant only in the non-operated side (P<0.01). Post-rehabilitation median scores of the questionnaire indicated a positive judgment of the treatment. EMG analysis showed that functional recovery in hemimandibulectomy patients was satisfactory, although some alterations were observed in the non-operated side of mastication.

  12. Hearing loss patterns after cochlear implantation via the round window in an animal model.

    Science.gov (United States)

    Attias, Joseph; Hod, Roy; Raveh, Eyal; Mizrachi, Aviram; Avraham, Karen B; Lenz, Danielle R; Nageris, Ben I

    2016-01-01

    The mechanism and the type of hearing loss induced by cochlear implants are mostly unknown. Therefore, this study evaluated the impact and type of hearing loss induced by each stage of cochlear implantation surgery in an animal model. Original basic research animal study. The study was conducted in a tertiary, university-affiliated medical center in accordance with the guidelines of the Institutional Animal Care and Use Committee. Cochlear implant electrode array was inserted via the round window membrane in 17 ears of 9 adult-size fat sand rats. In 7 ears of 5 additional animals round window incision only was performed, followed by patching with a small piece of periosteum (control). Hearing thresholds to air (AC) and bone conduction (BC), clicks, 1 kHz and 6 kHz tone bursts were measured by auditory brainstem evoked potential, before, during each stage of surgery and one week post-operatively. In addition, inner ear histology was performed. The degree of hearing loss increased significantly from baseline throughout the stages of cochlear implantation surgery and up to one week after (plosses were found for 1-kHz and 6-kHz frequencies. The hearing loss was not associated with significant changes in inner ear histology. Hearing loss following cochlear implantation in normal hearing animals is progressive and of mixed type, but mainly conductive. Changes in the inner-ear mechanism are most likely responsible for the conductive hearing loss. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Long-term survival rate of implant-supported overdentures with various attachment systems: A 20-year retrospective study

    Directory of Open Access Journals (Sweden)

    Hao-Sheng Chang

    2015-03-01

    Conclusion: The overall survival rate of dental implants with overdenture rehabilitation was 95.3% (91.3% in maxillae vs. 96.4% in mandibles within the past 20 years. With careful treatment planning, implant-supported overdenture is an interesting treatment alternative with better esthetic, retention, stability, and good hygienic maintenance for patients with severe ridge resorption.

  14. A retrospective 3- to 5-year study of the reconstruction of oral function using implant-supported prostheses in patients with hypohidrotic ectodermal dysplasia.

    Science.gov (United States)

    Zou, Duohong; Wu, Yiqun; Wang, Xu Dong; Huang, Wei; Zhang, Zhiyong; Zhang, Zhiyuan

    2014-10-01

    The aim of this study was to evaluate oral function rehabilitation in patients with hypohidrotic ectodermal dysplasia (HED) using implant-supported prostheses based on bone augmentation. From September 2005 and March 2009, 25 HED patients were chosen for clinical data analysis in this study. The criteria for patient selection included the following: the display of clinical features of HED, the number of congenitally missing teeth (>5), the patient age (>16 years), the patient's willingness, and the patient's tolerance for bone graft surgery and implant placement. Follow-up evaluations were initiated from the time of implant prosthetic placement and scheduled annually for 3-5 years. The effects of oral function reconstruction were assessed based on the cumulative survival and success rates of implants, the health of the peri-implant area, and the degree of patient satisfaction. Twenty-five HED patients received 169 conventional implants and 10 zygomatic implants (179 total implants). During 3-5 years of post-loading evaluations, 5 of the 179 implants failed and 3 implants were removed. The 3-year success and cumulative survival rates were 97.2% and 98.3%, respectively. Furthermore, periodontal probing and radiographic assessments showed that the 3-year incidence of peri-implantitis was 4.5%. Finally, HED patients expressed high degrees of satisfaction with their facial contours, masticatory function, pronunciation ability, and comfort with the implant-supported prostheses. The results of this 3- to 5-year retrospective study indicate that the oral function of HED patients can be effectively reconstructed using bone augmentation and implant-supported prostheses; however, longer term results are warranted in the future.

  15. Nuclear reactor fuel element containing an end piece for maintaining the column of fuel pellets

    International Nuclear Information System (INIS)

    Pajot, Jacques; Rabellino, Jacques.

    1974-01-01

    The nuclear reactor fuel element described has an end piece for maintaining the column of fuel pellets in position inside the element cladding. This end piece has a central compression spring one end of which presses against the pellets and the other against a plug shaped piece fitted with a seat for the spring, a conical piece with an elastic ring around it diverging towards the end in contact with the spring and a head at the opposite end. The connection between the compression spring and the pellets is through an application piece. A central bore provided in the end piece helps balance the pressure inside the element. This element is particularly intended for liquid metal cooled fast neutron reactors [fr

  16. Attachment-retained gingival prosthesis for implant-supported fixed dental prosthesis in the maxilla: a clinical report.

    Science.gov (United States)

    Aparecida de Mattias Sartori, Ivete; Uhlendorf, Yuri; Padovan, Luiz Eduardo Marques; Junior, Paulo Domingos Ribeiro; Melo, Ana Cláudia Moreira; Tiossi, Rodrigo

    2014-12-01

    The rehabilitation of edentulous maxillae is a complex procedure due to the involvement of esthetic and functional requirements. A trial maxillary denture can be used to identify the need for adequate upper lip support when replacing removable complete dentures by implant-fixed dental prostheses. This clinical report describes the outcome of the rehabilitation of an edentulous atrophic maxilla with unfavorable maxillomandibular relationship and deficient upper lip support. A trial denture was fabricated and used to diagnose the need for a prosthesis capable of restoring the upper lip support. The reduced upper lip support was also confirmed by a lateral cephalogram. The patient was rehabilitated by an implant-fixed dental prosthesis associated with an attachment-retained gingival prosthesis. The case presented shows that when loss of upper lip support is detected and the patient does not wish to undergo further surgical reconstruction procedure, the retention of a gingival prosthesis using a ball attachment is a satisfactory treatment option. © 2014 by the American College of Prosthodontists.

  17. Inflatable penile prosthesis implant length with baseline characteristic correlations: preliminary analysis of the PROPPER study.

    Science.gov (United States)

    Bennett, Nelson; Henry, Gerard; Karpman, Edward; Brant, William; Jones, LeRoy; Khera, Mohit; Kohler, Tobias; Christine, Brian; Rhee, Eugene; Kansas, Bryan; Bella, Anthony J

    2017-12-01

    "Prospective Registry of Outcomes with Penile Prosthesis for Erectile Restoration" (PROPPER) is a large, multi-institutional, prospective clinical study to collect, analyze, and report real-world outcomes for men implanted with penile prosthetic devices. We prospectively correlated co-morbid conditions and demographic data with implanted penile prosthesis size to enable clinicians to better predict implanted penis size following penile implantation. We present many new data points for the first time in the literature and postulate that radical prostatectomy (RP) is negatively correlated with penile corporal length. Patient demographics, medical history, baseline characteristics and surgical details were compiled prospectively. Pearson correlation coefficient was generated for the correlation between demographic, etiology of ED, duration of ED, co-morbid conditions, pre-operative penile length (flaccid and stretched) and length of implanted penile prosthesis. Multivariate analysis was performed to define predictors of implanted prosthesis length. From June 2011 to June 2017, 1,135 men underwent primary implantation of penile prosthesis at a total of 11 study sites. Malleable (Spectra), 2-piece Ambicor, and 3-piece AMS 700 CX/LGX were included in the analysis. The most common patient comorbidities were CV disease (26.1%), DM (11.1%), and PD (12.4%). Primary etiology of ED: RP (27.4%), DM (20.3%), CVD (18.0%), PD (10.3%), and Priapism (1.4%), others (22.6%). Mean duration of ED is 6.2¡À4.1 years. Implant length was weakly negatively correlated with White/Caucasian (r=-0.18; Pprosthesis length is negatively correlated with some ethnic groups, prostatectomy, and incontinence. Positive correlates include CV disease, preoperative stretched penile length, and flaccid penile length.

  18. Fixed Full Arches Supported by Tapered Implants with Knife-Edge Thread Design and Nanostructured, Calcium-Incorporated Surface: A Short-Term Prospective Clinical Study

    Directory of Open Access Journals (Sweden)

    Soheil Bechara

    2017-01-01

    Full Text Available Purpose. To evaluate implant survival, peri-implant bone loss, and complications affecting fixed full-arch (FFA restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface. Methods. Between January 2013 and December 2015, all patients referred for implant-supported FFA restorations were considered for enrollment in this study. All patients received implants with a knife-edge thread design and nanostructured calcium-incorporated surface (Anyridge®, Megagen, South Korea were restored with FFA restorations and enrolled in a recall program. The final outcomes were implant survival, peri-implant bone loss, biologic/prosthetic complications, and “complication-free” survival of restorations. Results. Twenty-four patients were selected. Overall, 215 implants were inserted (130 maxilla, 85 mandible, 144 in extraction sockets and 71 in healed ridges. Thirty-six FFAs were delivered (21 maxilla, 15 mandible: 27 were immediately loaded and 9 were conventionally loaded. The follow-up ranged from 1 to 3 years. Two fixtures failed, yielding an implant survival rate of 95.9% (patient-based. A few complications were registered, for a “complication-free” survival of restorations of 88.9%. Conclusions. FFA restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface are successful in the short term, with high survival and low complication rates; long-term studies are needed to confirm these outcomes.

  19. Application of interconnected porous hydroxyapatite ceramic block for onlay block bone grafting in implant treatment: A case report.

    Science.gov (United States)

    Ohta, Kouji; Tada, Misato; Ninomiya, Yoshiaki; Kato, Hiroki; Ishida, Fumi; Abekura, Hitoshi; Tsuga, Kazuhiro; Takechi, Masaaki

    2017-12-01

    Autogenous block bone grafting as treatment for alveolar ridge atrophy has various disadvantages, including a limited availability of sufficiently sized and shaped grafts, donor site morbidity and resorption of the grafted bone. As a result, interconnected porous hydroxyapatite ceramic (IP-CHA) materials with high porosity have been developed and used successfully in orthopedic cases. To the best of the author's knowledge, this is the first report of clinical application of an IP-CHA block for onlay grafting for implant treatment in a patient with horizontal alveolar atrophy. The present study performed onlay block grafting using an IP-CHA block to restore bone volume for implant placement in the alveolar ridge area without collecting autogenous bone. Dental X-ray findings revealed that the border of the IP-CHA block became increasingly vague over the 3-year period, whereas CT scanning revealed that the gap between the block and bone had a smooth transition, indicating that IP-CHA improved the process of integration with host bone. In follow-up examinations over a period of 5 years, the implants and superstructures had no problems. An IP-CHA block may be useful as a substitute for onlay block bone grafting in implant treatment.

  20. Self-organization of nickel nanoparticles dispersed in acetone: From separate nanoparticles to three-dimensional superstructures

    Directory of Open Access Journals (Sweden)

    I. Hernández-Pérez

    2017-02-01

    Full Text Available Sonochemical synthesis of monodisperse nickel nanoparticles (Ni-NPs by reduction of Ni acetylacetonate in the presence of polyvinylpyrrolidone stabilizer is reported. The Ni-NPs size is readily controlled to 5 nanometer diameter with a standard deviation of less than 5%. The as-prepared Ni-NPs sample was dispersed in acetone, for 4 weeks. For structural analysis was not applied to a magnetic field or heat treatment as key methods to direct the assembly. The transition from separate Ni-NPs into self-organization of three dimensions (3D superstructures was studied by electron microscopy. Experimental analysis suggests that the translation and rotation movement of the Ni-NPs are governed by magnetic frustration which promotes the formation of different geometric arrangements in two dimensions (2D. The formation of 3D superstructures is confirmed from scanning electron microscopy revealing a layered domain that consists of staking of several monolayers having multiple well-defined supercrystalline domains, enabling their use for optical, electronic and sensor applications.

  1. Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA.

    Science.gov (United States)

    Qamheya, Ala Hassan A; Yeniyol, Sinem; Arısan, Volkan

    2015-01-01

    Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC) material in teeth construction to rehabilitate a complete denture wearer patient.

  2. Neutron activation analysis for calibration of phosphorus implantation dose

    International Nuclear Information System (INIS)

    Paul, Rick L.; Simons, David S.

    2001-01-01

    A feasibility study was undertaken to determine if radiochemical neutron activation analysis (RNAA) can be used to certify the retained dose of phosphorus implanted in silicon, with the goal of producing a phosphorus SRM. Six pieces of silicon, implanted with a nominal phosphorus dose of 8.5x10 14 atoms·cm -2 were irradiated at a neutron flux of 1.05x10 14 cm -2 ·s -1 . The samples were mixed with carrier, dissolved in acid, the phosphorus isolated by chemical separation, and 32 P measured using a beta proportional counter. A mean phosphorus concentration of (8.35±0.20)x10 14 atoms·cm -2 (uncertainty=1 standard deviation) was determined for the six samples, in agreement with the nominal implanted dose

  3. Implant-supported Oral Rehabilitation in Child with Ectodermal Dysplasia - 4-year Follow-up.

    Science.gov (United States)

    Cezária Triches, Thaisa; Ximenes, Marcos; Oliveira de Souza, João Gustavo; Rodrigues Lopes Pereira Neto, Armando; Cardoso, Antônio Carlos; Bolan, Michele

    2017-01-01

    Ectodermal dysplasia (ED) is an anomaly determined by genetic factors that alter ectodermal structures such as skin, hair, nails, glands, and teeth. Children affected by this condition require extensive, comprehensive, and multidisciplinary treatment. An 8-year-old female patient visited the Dentistry Clinic of the Federal University of Santa Catarina with the chief complaint of multiple missing teeth. The mother reported that the patient had ED. Clinical and radiographic examination revealed the congenital absence of several primary and permanent teeth and tooth germs. Subsequent oral rehabilitation comprised the application of a maxillary denture and mandibular implant-supported fixed prosthesis. The child was also supplied with a wig for further enhancement of esthetics aimed at improving her emotional wellbeing. Psychological follow-up and speech therapy were also provided. After 4 years of follow-up, implant-supported oral rehabilitation has proved to be a satisfactory treatment option, allowing restoration of masticatory, phonetic, and esthetic function, as well as an improvement in the patient's self-esteem and social wellbeing.

  4. [Emotional response to music by postlingually-deafened adult cochlear implant users].

    Science.gov (United States)

    Wang, Shuo; Dong, Ruijuan; Zhou, Yun; Li, Jing; Qi, Beier; Liu, Bo

    2012-10-01

    To assess the emotional response to music by postlingually-deafened adult cochlear implant users. Munich music questionnaire (MUMU) was used to match the music experience and the motivation of use of music between 12 normal-hearing and 12 cochlear implant subjects. Emotion rating test in Musical Sounds in Cochlear Implants (MuSIC) test battery was used to assess the emotion perception ability for both normal-hearing and cochlear implant subjects. A total of 15 pieces of music phases were used. Responses were given by selecting the rating scales from 1 to 10. "1" represents "very sad" feeling, and "10" represents "very happy feeling. In comparison with normal-hearing subjects, 12 cochlear implant subjects made less active use of music for emotional purpose. The emotion ratings for cochlear implant subjects were similar to normal-hearing subjects, but with large variability. Post-lingually deafened cochlear implant subjects on average performed similarly in emotion rating tasks relative to normal-hearing subjects, but their active use of music for emotional purpose was obviously less than normal-hearing subjects.

  5. A 3-year prospective clinical study of telescopic crown, bar, and locator attachments for removable four implant-supported maxillary overdentures.

    Science.gov (United States)

    Zou, Duohong; Wu, Yiqun; Huang, Wei; Wang, Feng; Wang, Shen; Zhang, Zhiyong; Zhang, Zhiyuan

    2013-01-01

    To evaluate telescopic crown (TC), bar, and locator attachments used in removable four implant-supported overdentures for patients with edentulous maxillae. A total of 30 maxillary edentulous patients were enrolled in a 3-year prospective study. Ten patients (group A) were treated with overdentures supported by TCs, 10 patients (group B) with overdentures supported by bar attachments, and 10 patients (group C) with overdentures supported by locator attachments. A total of 120 implants were used to restore oral function. During the 3-year follow-up period, implant survival and success rates, biologic and mechanical complications, prosthodontic maintenance efforts, and patient satisfaction were evaluated. All 30 patients were available for the 3-year follow-up and exhibited 100% implant survival and success rates. Peri-implant marginal bone resorption was not statistically significant for the three groups. There were lower plaque, bleeding, gingiva, and calculus indices in group C compared with groups A and B. The number of prosthodontic maintenance visits revealed eight complications in the TC group, seven complications in the bar group, and four complications in the locator group. However, there were no differences in the clinical effects of the overdentures in the three groups. Within the limits of this prospective study, it was concluded that the locator system produced superior clinical results compared with the TC and bar attachments in terms of peri-implant hygiene parameters, the frequency of prosthodontic maintenance measures, cost, and ease of denture preparation. However, longer-term prospective studies are required to confirm these results.

  6. Application of digital diagnostic impression, virtual planning, and computer-guided implant surgery for a CAD/CAM-fabricated, implant-supported fixed dental prosthesis: a clinical report.

    Science.gov (United States)

    Stapleton, Brandon M; Lin, Wei-Shao; Ntounis, Athanasios; Harris, Bryan T; Morton, Dean

    2014-09-01

    This clinical report demonstrated the use of an implant-supported fixed dental prosthesis fabricated with a contemporary digital approach. The digital diagnostic data acquisition was completed with a digital diagnostic impression with an intraoral scanner and cone-beam computed tomography with a prefabricated universal radiographic template to design a virtual prosthetically driven implant surgical plan. A surgical template fabricated with computer-aided design and computer-aided manufacturing (CAD/CAM) was used to perform computer-guided implant surgery. The definitive digital data were then used to design the definitive CAD/CAM-fabricated fixed dental prosthesis. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  7. The Key Points of Maintenance Therapy for Dental Implants: A Literature Review.

    Science.gov (United States)

    Pirc, Miha; Dragan, Irina F

    2017-04-01

    Dental implants require lifelong maintenance and care. Success is defined by biologic factors (presence of inflamed soft tissues surrounding dental implants and radiographic changes in the crestal bone levels) and mechanical factors (stability of the implant fixture and implant supported restoration, etc). Most implant failures are initiated by incipient stages of inflammatory processes, which lead to peri-mucositis and peri-implantitis. The evidence regarding the value of maintenance protocol regarding implants is sparse compared with the one for teeth. This article addresses the existing literature on processes for oral hygiene for implant care.

  8. Use of SIG device to accurately place permanent miniature dental implants to retain mandibular overdenture. A case report.

    Science.gov (United States)

    Sussman, Harold I; Goodridge, Opal F

    2006-01-01

    A case of mini-dental implant insertion for retention of a mandibular overdenture in a hospitalized patient has been documented. The additional use of the SIG (drill guide) directional device in the implant placement protocol gave the practitioner more confidence and resulted in the proper alignment of the three ball-top, one-piece fixtures. The three implants were inserted exactly 1 cm apart and parallel to each other. The distal fixtures were approximately 1 cm away from the mental foramina, thereby eliminating the risk of lip paresthesia. Keeper caps were placed in the denture's intaglio after one month. The keeper caps allowed for proper retention of the overdenture. The caps also enabled the patient to easily insert and withdraw his denture, even though he displayed limited manual dexterity. The tissue response was excellent, and oral hygiene was made easier with adequate spacing of the exposed ball-tops. The overall experience for both the operator and the patient was very positive. General dentists should be able to readily master this technique and add it to their armamentarium for the benefit of all their patients.

  9. The behavior of implant-supported dentures and abutments using the cemented cylinder technique with different resinous cements

    Directory of Open Access Journals (Sweden)

    Ivete Aparecida de Mathias Sartori

    2008-01-01

    Full Text Available Objective: Evaluate the behavior of implant-supported dentures and their components, made by cemented cylinder technique, using threetypes of resin cements. Methods: Fifty three patients, of whom 26 were women and 27 men, aged between 25 and 82 years. Results: With partial (54.43% and total (45.57% implant-supported dentures, of the Cone Morse, external and internal hexagon types (Neodent®, Curitiba, Brazil, totaling 237 fixations, were analyzed. The resin cements used were Panavia® (21.94%, EnForce® (58.23% and Rely X® (19.83% and the components were used in accordance with the Laboratory Immediate Loading - Neodent® sequence. The period of time of denture use ranged between 1 and 5 years. The results reported that 5(2.1% cylinders were loosened from metal structure (both belonging to Rely X group, 2(0.48% implants were lost after the first year of use, 16(6.75% denture retention screws wereloosened and 31(13.08% abutment screws were unloosened.Conclusion: The reasons for these failures probably are: metal structure internal retention failure, occlusal pattern, cementation technique and loading conditions. The cemented cylinder technique was effective when used in partial and total implant-supported rehabilitations, keeping prosthetic components stable, despite the resin cement utilized. However, further clinical studies must be conducted.

  10. Influence of Manufacturing Methods of Implant-Supported Crowns on External and Internal Marginal Fit: A Micro-CT Analysis

    Directory of Open Access Journals (Sweden)

    Izabela C. M. Moris

    2018-01-01

    Full Text Available Aim. To evaluate the influence of different manufacturing methods of single implant-supported metallic crowns on the internal and external marginal fit through computed microtomography. Methods. Forty external hexagon implants were divided into 4 groups (n=8, according to the manufacturing method: GC, conventional casting; GI, induction casting; GP, plasma casting; and GCAD, CAD/CAM machining. The crowns were attached to the implants with insertion torque of 30 N·cm. The external (vertical and horizontal marginal fit and internal fit were assessed through computed microtomography. Internal and external marginal fit data (μm were submitted to a one-way ANOVA and Tukey’s test (α=.05. Qualitative evaluation of the images was conducted by using micro-CT. Results. The statistical analysis revealed no significant difference between the groups for vertical misfit (P=0.721. There was no significant difference (P>0.05 for the internal and horizontal marginal misfit in the groups GC, GI, and GP, but it was found for the group GCAD (P≤0.05. Qualitative analysis revealed that most of the samples of cast groups exhibited crowns underextension while the group GCAD showed overextension. Conclusions. The manufacturing method of the crowns influenced the accuracy of marginal fit between the prosthesis and implant. The best results were found for the crowns fabricated through CAD/CAM machining.

  11. Application of a generic superstructure-based formulation to the design of wind-pumped-storage hybrid systems on remote islands

    International Nuclear Information System (INIS)

    Chen, Cheng-Liang; Chen, Hui-Chu; Lee, Jui-Yuan

    2016-01-01

    Highlights: • A rigorous model for hybrid power system (HPS) design to support a remote island. • Use pumped hydro storage to store tentative surplus electricity. • Formulate the HPS design problem as a mixed-integer linear program (MILP). - Abstract: This paper aims to present a mathematical model for the design of a hybrid power system (HPS) to support a remote island with 100 thousand citizens. The goal is to reduce diesel fuel consumption by adequate expansion of wind power supply. Pumped hydroelectric storage (PHS) is used in the HPS to buffer the impact of intermittent behavior of wind energy. A superstructure is proposed for HPS design, considering all possible capital decisions (e.g. the number of wind turbines) and hourly-basis operational variables (such as the amount of surplus electricity in storage and its discharge). The HPS design problem can then be formulated as a mixed-integer linear program (MILP) based on the proposed superstructure. For a given total share of wind power, the optimal mix of diesel-based and wind power supplies as well as the required capacity of PHS are determined using a four-step optimization approach, involving minimizing (i) the consumption of diesel fuel, (ii) the number of wind turbines, (iii) the size of the upper water reservoir, and (iv) the charge/discharge rates of the PHS system. In this sequential optimization, the objective value obtained in a previous step is added as an additional constraint to the next step. The proposed HPS design model is applied to a real case study of the remote K Island on the other side of Taiwan Strait using hourly-basis, year-round historical data. Inclusion of other renewable energy sources, such as photovoltaic cells and biomass-fired power plants, as well as economic perspectives will be considered in future work.

  12. A comparison of laser-welded titanium and conventional cast frameworks supported by implants in the partially edentulous jaw: a 3-year prospective multicenter study.

    Science.gov (United States)

    Jemt, T; Henry, P; Lindén, B; Naert, I; Weber, H; Bergström, C

    2000-01-01

    The purpose of this prospective multicenter study was to evaluate and compare the clinical performance of laser-welded titanium fixed partial implant-supported prostheses with conventional cast frameworks. Forty-two partially edentulous patients were provided with Brånemark system implants and arranged into 2 groups. Group A was provided with a conventional cast framework with porcelain veneers in one side of the jaw and a laser-welded titanium framework with low-fusing porcelain on the other side. The patients in group B had an old implant prosthesis replaced by a titanium framework prosthesis. The patients were followed for 3 years after prosthesis placement. Clinical and radiographic data were collected and analyzed. Only one implant was lost, and all prostheses were still in function after 3 years. The 2 framework designs showed similar clinical performance with few clinical complications. Only one abutment screw (1%) and 9 porcelain tooth units (5%) fractured. Four prostheses experienced loose gold screws (6%). In group A, marginal bone loss was similar for both designs of prostheses, with a mean of 1.0 mm and 0.3 mm in the maxilla and mandible, respectively. No bone loss was observed on average in group B. No significant relationship (P > 0.05) was observed between marginal bone loss and placement of prosthesis margin or prosthesis design. The use of laser-welded titanium frameworks seems to present similar clinical performance to conventional cast frameworks in partial implant situations after 3 years.

  13. An in vitro investigation into retention strength and fatigue resistance of various designs of tooth/implant supported overdentures.

    Science.gov (United States)

    Fatalla, Abdalbseet A; Song, Ke; Du, Tianfeng; Cao, Yingguang

    2012-02-01

    Previously, the choice of prosthetic implant-retained overdentures has depended on data from previous studies about the retention-fatigue strength of the attachment system selected. Little or no data have been available on the correlation between the attachment system selected and the overdenture support configuration. The purpose of the present study was to evaluate the retention force and fatigue resistance of three attachment systems and four support designs of overdenture prosthesis. Four lower edentulous acrylic models were prepared and eight combinations of attachments groups were investigated in the study. These included: O-Rings with mini-dental implants (MDIs), Dalbo elliptic with Dalbo Rotex and fabricated flexible acrylic attachments with both MDI and Dalbo Rotex. The study was divided into four test groups: groups A and B, controls, and groups C and D, experimental groups. Control group A contained three overdenture supports: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with Dalbo Rotex screwed in. Control group B contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with Dalbo Rotex screwed in at the same MDI position, but on the left side of the model. Experimental group C contained three overdenture support foundations: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with MDI screwed in. Experimental group D contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with MDIs screwed in at the same MDI position, but on the left side of the model. Each group was further divided into two subgroups according to attachment type used. Five samples were prepared for each group. Retention force (N) values were recorded initially (0 cycles) and after 360, 720, 1440

  14. Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA

    Directory of Open Access Journals (Sweden)

    Ala Hassan A. Qamheya

    2015-01-01

    Full Text Available Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC material in teeth construction to rehabilitate a complete denture wearer patient.

  15. Three-dimensional accuracy of different impression techniques for dental implants

    Directory of Open Access Journals (Sweden)

    Mohammadreza Nakhaei

    2015-01-01

    Full Text Available Background: Accurate impression making is an essential prerequisite for achieving a passive fit between the implant and the superstructure. The aim of this in vitro study was to compare the three-dimensional accuracy of open-tray and three closed-tray impression techniques. Materials and Methods: Three acrylic resin mandibular master models with four parallel implants were used: Biohorizons (BIO, Straumann tissue-level (STL, and Straumann bone-level (SBL. Forty-two putty/wash polyvinyl siloxane impressions of the models were made using open-tray and closed-tray techniques. Closed-tray impressions were made using snap-on (STL model, transfer coping (TC (BIO model and TC plus plastic cap (TC-Cap (SBL model. The impressions were poured with type IV stone, and the positional accuracy of the implant analog heads in each dimension (x, y and z axes, and the linear displacement (ΔR were evaluated using a coordinate measuring machine. Data were analyzed using ANOVA and post-hoc Tukey tests (α = 0.05. Results: The ΔR values of the snap-on technique were significantly lower than those of TC and TC-Cap techniques (P < 0.001. No significant differences were found between closed and open impression techniques for STL in Δx, Δy, Δz and ΔR values (P = 0.444, P = 0.181, P = 0.835 and P = 0.911, respectively. Conclusion: Considering the limitations of this study, the snap-on implant-level impression technique resulted in more three-dimensional accuracy than TC and TC-Cap, but it was similar to the open-tray technique.

  16. The role of welding techniques in the biomechanical behavior of implant-supported prostheses.

    Science.gov (United States)

    Rodrigues, Sabrina Alessandra; Presotto, Anna Gabriella Camacho; Barão, Valentim Adelino Ricardo; Consani, Rafael Leonardo Xediek; Nóbilo, Mauro Antônio Arruda; Mesquita, Marcelo Ferraz

    2017-09-01

    This in vitro study investigated the role of welding techniques of implant-supported prostheses in the 2D and 3D marginal misfits of prosthetic frameworks, strain induced on the mini abutment, and detorque of prosthetic screws. The correlations between the analyzed variables were also investigated. Frameworks were cast in commercially pure titanium (cp-Ti). A marginal misfit of 200μm was simulated in the working models (control group) (n=20). The 2D marginal misfit was analyzed according to the single-screw test protocol using a precision optical microscope. The 3D marginal misfit was performed by X-ray microtomography. Strain gauge analysis was performed to investigate the strain induced on the mini abutment. A digital torque meter was used for analysis of the detorque and the mean value was calculated for each framework. Afterwards, the frameworks were divided into two experimental groups (n=10): Laser (L) and TIG (T). The welding techniques were performed according to the following parameters: L (390V/9ms); T (36A/60ms). The L and T groups were reevaluated according to the marginal misfit, strain, and detorque. The results were submitted to one-way ANOVA followed by Tukey's HSD test and Person correlation analysis (α=0.05). Welding techniques statistically reduced the 2D and 3D marginal misfits of prosthetic frameworks (p0.05). Positive correlations were observed between 2D and 3D marginal misfit reading methods (r=0.943, pwelding techniques improved the biomechanical behavior of the implant-supported system. TIG can be an acceptable and affordable technique to reduce the misfit of 3-unit Ti frameworks. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Corrosion behavior of coated and uncoated bio implants in SBF(simulated body fluid)

    International Nuclear Information System (INIS)

    Iqbal, W.; Zahra, N.; Alam, S.; Habib, F.; Irfan, M.

    2013-01-01

    Surgical implants used in medical applications are basically the specific type of stainless steel materials. Stainless steel has been used widely and successfully for various types of trauma and orthopedic reconstructions. If an uncoated (bare) stainless steel metal piece is implanted in any part of the body, it will get corrode in Simulated Body Fluid (SBF) present inside the human body (a mixture of different salts). To overcome this problem a coating of Titanium Nitride (TiN) was developed on stainless steel bio-implants using physical vapor deposition (PVD) method. Both coated and uncoated implants were kept dipped in Simulated Body Fluid for five months. The samples were removed and tested for corrosion life assessment after every fifteen days using weight loss method. (author)

  18. Superstructure formation in PrNi{sub 2}Al{sub 3} and ErPd{sub 2}Al{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Eustermann, Fabian; Hoffmann, Rolf-Dieter [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Janka, Oliver [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Oldenburg Univ. (Germany). Inst. fuer Chemie

    2017-09-01

    The intermetallic phase ErPd{sub 2}Al{sub 3} was obtained by arc-melting of the elements and subsequent annealing for crystal growth. The sample was studied by X-ray diffraction on powders and single crystals. The structure of ErPd{sub 2}Al{sub 3} was refined from X-ray diffraction data and revealed a superstructure of PrNi{sub 2}Al{sub 3} - a CaCu{sub 5} derivative (P6/m, a=1414.3(1), c=418.87(3) pm wR=0.0820, 1060 F{sup 2} values, 48 variables). The same superstructure was subsequently found for PrNi{sub 2}Al{sub 3} (P6/m, a=1407.87(4), c=406.19(2) pm, wR=0.0499, 904 F{sup 2} values, 47 variables). In the crystal structure, the aluminium and transition metal atoms form a polyanionic network according to [T{sub 2}Al{sub 3}]{sup δ-}, while rare earth atoms fill cavities within the networks. They are coordinated by six transition metal and twelve aluminum atoms. In contrast to the PrNi{sub 2}Al{sub 3} type structure reported so far, two crystallographic independent rare-earth sites are found of which one (1b) is shifted by 1/2 z, causing a distortion in the structure along with a recoloring of the T and Al atoms in the network.

  19. A Prospective Study of Early Loaded Single Implant-Retained Mandibular Overdentures: Preliminary One-Year Results

    Directory of Open Access Journals (Sweden)

    Ali M. El-Sheikh

    2012-01-01

    Full Text Available Purpose. To investigate the predictability of simplifying mandibular overdenture treatment using one-stage surgery and early prosthetic loading of a single implant. Materials and Methods. Twenty edentulous patients with problematic existing mandibular dentures were treated. A single implant with a chemically modified surface (SLActive, Straumann AG, Basel, Switzerland was placed into the mandibular midline. The patients were recalled at 3, 6 and 12 months. Clinical assessments and marginal bone loss using standardized radiographs were recorded. All complications, failures and maintenance were noted. Visual analog-scale questionnaires were used to record patient satisfaction in five categories. ANOVA was used to determine differences between means of marginal bone loss and different categories of patient staisfaction (=0.05. Results. The 20 early loaded implants were all surviving at the 12-month recall. All implants showed less than 1 mm of marginal bone loss by the end of the 1-year with a significant increase during the follow-up period. Few prosthetic problems were reported. Patient satisfaction was high with a significant increase in all comfort and functional parameters. Conclusions. These preliminary 1-year results indicate that early loading of a single chemically modified surface implant used to retain a mucosa-borne mandibular overdenture is a safe, reliable, and cost-effective treatment.

  20. Combination of straight and tilted implants for supporting screw-retained dental prostheses in atrophic posterior maxillae: A 2-year prospective study.

    Science.gov (United States)

    Casar-Espinosa, Juan-Carlos; Castillo-Oyagüe, Raquel; Serrera-Figallo, María Ángeles; Garrido-Serrano, Roberto; Lynch, Christopher D; Menéndez-Collar, Manuel; Torres-Lagares, Daniel; Gutiérrez-Pérez, José-Luis

    2017-08-01

    To evaluate the two-year survival rate (SR) and marginal bone loss (MBL) of fixed dental prostheses (FDPs) supported by straight (S) and tilted (T) implants under the influence of diverse study variables. A prospective investigation comprising 21 patients provided with a total of 27 maxillary screw-retained restorations fixed to 70 dental implants was developed. Two groups of implants were considered depending on their inclination with respect to the occlusal plane: Group 1 (S, n=37): straight/axial implants and Group 2 (T, n=33): tilted/angled fixations. Each FDP was supported by a combination of S and T implants. SR and MBL were assessed at the time of loading and two years after surgery. Patient-, surgical- and/or rehabilitation-related information was gathered. Data were statistically analysed at the α=0.05 significance level. After 24 months, a 100% SR was achieved and the MBL of S and T implants were statistically similar. T implants located in the molar region showed lower MBL than did those replacing premolars (p=0.031). Upright and angled fixations inserted at posterior maxillary areas resulted in comparable survival rates and peri-implant MBL after two years. The marginal bone resorption around tilted implants depended on their location. Screw-retained restorations fixed to straight and tilted implants seem to be a safe treatment option in posterior atrophic maxillae. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Evaluation of Stress Distribution of Mini Dental Implant-Supported Overdentures in Complete Cleft Palate Models: A Three-Dimensional Finite Element Analysis Study.

    Science.gov (United States)

    Soğancı, Gökçe; Yazıcıoğlu, Hüseyin

    2016-01-01

    Mini dental implants could be an alternative treatment method for prosthetic treatment of edentulous cleft palate. The aim of this study was to analyze stress distribution around the cortical bone and different plans using a varied number of mini dental implants in edentulous unilateral complete cleft palates. Three edentulous maxillary models were modified to create unilateral complete cleft palates. Mini dental implants (2.4 × 15 mm) were located as two mini implants at the premolar region, four mini implants at the premolar and molar region, and six mini implants at the first premolar, second premolar, and first molar regions in the models, respectively. Mucosa, o-ring/ball attachments, and overdentures were simulated. Vertical and horizontal loads of 100 N were applied on both the right and left molar teeth of the overdenture for each model. Maximum and minimum principal stress values and the distribution at cortical bone around the implants and cleft palates were evaluated by finite element analysis. Stress values under vertical loads were lower than values under horizontal loadings for all models. Stress values were found to be lower in the first model than in the second and third models. The highest stress values were found around implants in the second model. The unilateral feature of a complete cleft pattern affected the stress distribution. Stresses occured mostly around implants when the overdenture was supported by six implants; however, the stress distribution around implants was low with two implants because of tissue support.

  2. Processed bovine cartilage: an improved biosynthetic implant for contour defects

    International Nuclear Information System (INIS)

    Ersek, R.A.; Hart, W.G. Jr.; Greer, D.; Beisang, A.A.; Flynn, P.J.; Denton, D.R.

    1984-01-01

    Irradiated human cartilage has been found to be a superior implant material for correction of contour defects; however, availability problems have prevented this material from gaining wide acceptance. Implantation of processed irradiated bovine cartilage in primates and rabbits, as described here, provides strong evidence that this material performs like irradiated allograft cartilage antigenically and has certain cosmetic advantages over allograft cartilage. Our studies in primates have shown that there is no systemically measurable antibody-antigen reaction, either cellular or noncellular, to irradiated processed bovine cartilage. Neither primary nor second-set provocative implantations produced any measurable rejection. In rabbits, composite grafts of two pieces of irradiated bovine cartilage adjacent to each other were also well tolerated, with no measurable absorption and with capsule formation typical of a foreign body reaction to an inert object

  3. Unsplinted implants and teeth supporting maxillary removable partial dentures retained by telescopic crowns: a retrospective study with >6 years of follow-up.

    Science.gov (United States)

    Frisch, Eberhard; Ratka-Krüger, Petra; Wenz, Hans-Jürgen

    2015-09-01

    Data regarding tooth- and implant-supported maxillary removable partial dentures (TIRPDs) are scarce. The objective of this research was to perform a retrospective evaluation of the clinical long-term outcome of maxillary TIRPDs rigidly retained via telescopic crowns in patients undergoing supportive post-implant therapy (SIT). The inclusion criteria were met by 26 patients restored with maxillary TIRPDs between 1997 and 2011 in a private practice. Primary crowns (Marburg double crowns, MDCs) on teeth were cemented, whereas those on implants were screw-retained. Using patient records and data from a cross-sectional clinical examination in 2013, the survival rates of the teeth, implants and prostheses, together with the biological and technical complications, were analyzed. After 6.12 ± 3.80 (range: 2-16) years of loading, 23 non-smoking patients with 23 dentures supported by 60 implants and 66 teeth were available for assessment. Nine teeth (survival rate: 86.36%) were lost, whereas 1 implant (survival rate: 98.36%) failed because of peri-implantitis. Although 30 implants (50%) in 16 patients (69.57%) showed bleeding on probing (BOP+), no further peri-implantitis was observed. The mean peri-implant probing depth (PPD) was 3.68 ± 0.71 mm. All dentures were functional and required technical maintenance efforts amounting to 0.128 treatments per patient per year (T/P/Y). Within the limitations of this study, we conclude that TIRPDs retained via MDCs may represent a viable treatment option for patients with residual maxillary teeth. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Development of debris-resistant bottom end piece

    International Nuclear Information System (INIS)

    Sohn, Dong Seong; Lee, Jae Kyung; Hwang, Dae Hyun; Yim, Jung Sik; Song, Kee Nam; Oh, Dong Seok; Im, Hyun Tae

    1993-01-01

    Debris-related fuel failures has been identified to be one of the major causes of fuel failures recently occured in nuclear power plants. In order to reduce the possibility of debris-related fuel failures, it is necessary to prevent the debris from reaching to fuel rods. In this regard, it is important to develop Debris-Resistant Bottom End Piece. (Author)

  5. Immediate versus early loading of two implants placed with a flapless technique supporting mandibular bar-retained overdentures: a single-blinded, randomised controlled clinical trial.

    Science.gov (United States)

    Cannizzaro, Gioacchino; Leone, Michele; Esposito, Marco

    2008-01-01

    To evaluate the efficacy of immediate loading versus early loading at 6 weeks of bar-retained mandibular overdentures supported by two implants placed with a flapless technique. Sixty patients were randomised: 30 to the immediately loaded group and 30 to the early loaded group. To be immediately loaded, implants had to be inserted with a minimum torque > 48 Ncm. Outcome measures were prosthesis and implant failures, biological and biomechanical complications, patient satisfaction, and Implant Stability Quotient (ISQ) assessed with a resonance frequency analysis instrument. Sixty implants were placed in each group. Flaps had to be raised in nine patients to check drill direction or to better visualise the area after multiple teeth extraction. Two implants in two patients did not reach the planned insertion torque and were immediately replaced by larger diameters ones. After 1 year no drop out occurred and two early loaded implants failed in two patients. There were no statistically significant differences between groups for prosthesis failures, implant losses, complications, and mean ISQ values; however, patients in the immediately loaded group were significantly more satisfied than those loaded early. When comparing mean ISQ values taken 6 weeks after placement with 1-year data within each group, values decreased significantly. Mandibular overdentures can be successfully loaded the same day of implant placement with a minimally invasive surgery, increasing patient satisfaction while decreasing treatment time and patient discomfort. No apparent advantages were seen when loading the overdentures at 6 weeks.

  6. Macro design effects on stress distribution around implants: A photoelastic stress analysis

    OpenAIRE

    Serhat Emre Ozkir; Hakan Terzioglu

    2012-01-01

    Objectives: Biomechanics is one of the main factors for achieving long-term success of implant supported prostheses. Long-term failures mostly depend on biomechanical complications. It is important to distinguish the effects of macro design of the implants. Materials and Methods: In this study, the photoelastic response of four different types of implants that were inserted with different angulations were comparatively analyzed. The implant types investigated were screw cylinder (ITI, Str...

  7. Group D. Initiator paper. Implants--peri-implant (hard and soft tissue) interactions in health and disease: the impact of explosion of implant manufacturers.

    Science.gov (United States)

    Ivanovski, Saso

    2015-01-01

    1. The best-documented implants have a threaded solid screw-type design and are manufactured from commercially pure (grade IV) titanium. There is good evidence to support implants ≥ 6 mm in length, and ≥ 3 mm in diameter. 2. Integrity of the seal between the abutment and the implant is important for several reasons, including minimization of mechanical and biological complications and maintaining marginal bone levels. Although the ideal design features of the implant-abutment connection have not been determined, an internal connection, micro-grooves at the implant collar, and horizontal offset of the implant-abutment junction (platform switch) appear to impart favorable properties. 3. Implants with moderately rough implant surfaces provide advantages over machined surfaces in terms of the speed and extent of osseointegration. While the favorable performances of both minimally and moderately rough surfaces are supported by long-term data, moderately rough surfaces provide superior outcomes in compromised sites, such as the posterior maxilla. 4. Although plaque is critical in the progression of peri-implantitis, the disease has a multi-factorial aetiology, and may be influenced by poor integrity of the abutment/implant connection. Iatrogenic factors, such as the introduction of a foreign body. (e.g., cement) below the mucosal margin, can be important contributors. 5. Clinicians should exercise caution when using a particular implant system, ensuring that the implant design is appropriate and supported by scientific evidence. Central to this is access to and participation in quality education on the impact that implant characteristics can have on clinical outcomes. Caution should be exercised in utilizing non-genuine restorative componentry that may lead to a poor implant-abutment fit and subsequent technical and biological complications.

  8. Surface dimpling on rotating work piece using rotation cutting tool

    Science.gov (United States)

    Bhapkar, Rohit Arun; Larsen, Eric Richard

    2015-03-31

    A combined method of machining and applying a surface texture to a work piece and a tool assembly that is capable of machining and applying a surface texture to a work piece are disclosed. The disclosed method includes machining portions of an outer or inner surface of a work piece. The method also includes rotating the work piece in front of a rotating cutting tool and engaging the outer surface of the work piece with the rotating cutting tool to cut dimples in the outer surface of the work piece. The disclosed tool assembly includes a rotating cutting tool coupled to an end of a rotational machining device, such as a lathe. The same tool assembly can be used to both machine the work piece and apply a surface texture to the work piece without unloading the work piece from the tool assembly.

  9. A Critical Reassessment of Marxian Base-Superstructure Explanations of the Role of Education in Social Change.

    Science.gov (United States)

    Chun, Kyung-Kap

    1986-01-01

    Examines how four major versions of neo-Marxism (i.e., Hegelian, Phenomenological, Structuralist Marxism, and the Frankfurt School) attempt to overcome the base-superstructure thesis of the political economists of education. Considers the implicit social ontological and epistemological assumptions and the related theory of education of each.…

  10. Implant supported prosthesis in an edentulous boy with Hypohidrotic Ectodermal Dysplasia - "A happy boy"

    DEFF Research Database (Denmark)

    Gjørup, Hans; Nyhuus, Lone; Buhl, Jytte

    2009-01-01

    region. 3. At the age of 10 years a new set of dentures were made. This time the upper denture was made as an overdenture supported and retained by 4 implants and a Dolder bar. The surgical procedure included bone grafting from the anterior ramus mandibulae. The boy's subjective judgement of his oral......Implant supported prosthesis in an edentulous boy with Hypohidrotic Ectodermal Dysplasia - "A happy boy". Authors; Gjoerup,H1; Nyhuus,L2; Buhl,J3. 1) Center for Oral Health in Rare Conditions, Aarhus University Hospital 2) Prosthodontic Department, the Dental School, Aarhus University 3) Department...... by the patient and his family. Case presentation The boy was untreated until the age of 5 years. His oral functions were compromised in relation to speech and psychosocial aspects. In the following 6 years, he underwent prosthodontic treatment in three phases. 1. At the age of 5 years a set of complete dentures...

  11. A feasible, aesthetic quality evaluation of implant-supported single crowns: an analysis of validity and reliability

    DEFF Research Database (Denmark)

    Hosseini, Mandana; Gotfredsen, Klaus

    2012-01-01

    OBJECTIVES: To test the reliability and validity of six aesthetic parameters and to compare the professional- and patient-reported aesthetic outcomes. MATERIAL AND METHODS: Thirty-four patients with 66 implant-supported premolar crowns were included. Two prosthodontists and 11 dental students......,24) were found between patient and professional evaluations. CONCLUSIONS: The feasibility, reliability and validity of the CIS make the parameters useful for quality control of implant-supported restorations. The professional- and patient-reported aesthetic outcomes had no significant correlation....... and the internal consistency were analysed by Cohen's ¿ and Cronbach's a, respectively. The validity of CIS parameters was tested against the corresponding Visual Analogue Scales (VAS) scores. The Spearman correlation coefficients were used. Six aesthetic Oral Health Impact Profile (OHIP) questions were correlated...

  12. Oral rehabilitation with implant supported overdentures in patients with non-reconstructed segmental mandibulectomy: A report of two cases

    Directory of Open Access Journals (Sweden)

    Rok Zupančič

    2013-11-01

    Full Text Available Background: Segmental mandibulectomy is most often performed as part of resection of advanced squamous cell carcinoma, which involves the mandible by extension from intraoral tissues and is usually followed by reconstruction of the mandible. However, not all mandibular defects can be surgically reconstructed, due to local or systemic factors. Oral rehabilitation with conventional removable dentures is often insufficient. In order to provide predictable support and denture retention, especially in the non-reconstructed cases of segmental mandibulectomy, dental implants are indicated.Case report: The authors describe oral rehabilitation with implant-supported overdenture in two non-reconstructed patients with similar mandibular defect, but different etiology, as well as different denture design and different outcome in terms of success and patient satisfaction. In the first case, the defect was caused by surgical treatment of cancer, which was followed by radiotherapy and prosthodontic treatment with an implant-supported mandibular overdenture anchored with a bar. In another case, the damage was due to a suicide attempt. This was initially followed by the surgical treatment of the injury. Afterwards, the prosthodontic treatment with an implant-supported and conical–crown-anchored mandibular overdenture was performed.Conclusions: The success of the prosthodontic oral rehabilitation of patients with segmental mandibulectomy depends on many factors. The size of the defect and the condition of the remaining hard and soft tissues, which are affected by radiotherapy, are crucial. The etiology of the defect, the opposing jaw status, maxillomandibular relationships, the consistency of mandibular movement and the denture design play an important role as well.

  13. Comparative evaluation of the oral tactile function by means of teeth or implant-supported prostheses.

    Science.gov (United States)

    Jacobs, R; van Steenberghe, D

    1991-01-01

    To clarify more of the tactile function of oral implants, both an interocclusal thickness detection and discrimination task were carried out in 4 different test conditions on 37 patients: t (tooth)/t, i (implant)/t, i/i and d (denture)/o (overdenture supported by implants). For the interocclusal detection of steel foils, the 50% detection threshold level (RL) in the 4 conditions was 20, 48, 64 and 108 microns, respectively, which indicates significant differences. The ability to discriminate interdental thickness differences was tested with a 0.2 and 1.0 mm standard. It was evaluated as the 75% discrimination level (DL). In the 0.2 mm discrimination task, corresponding DL-values for the t/t, i/t, i/i and d/o condition were 25, 55, 66 and 134 microns, whereas the 1.0 mm standard gave values of 193, 293, 336 and 348 microns, respectively. All results differed significantly from each other (p less than 0.05) except for the i/i-d/o comparison of the 1.0 mm discrimination task where the difference was negligible. The present findings indicate that the tactile sensibility of implants is reduced with regard to natural teeth. Remaining receptors of the peri-implant tissues might play a compensatory role in the decreased exteroceptive function.

  14. Fractal dimension analysis of complexity in Ligeti piano pieces

    Science.gov (United States)

    Bader, Rolf

    2005-04-01

    Fractal correlation dimensional analysis has been performed with whole solo piano pieces by Gyrgy Ligeti at every 50ms interval of the pieces. The resulting curves of development of complexity represented by the fractal dimension showed up a very reasonable correlation with the perceptional density of events during these pieces. The seventh piece of Ligeti's ``Musica ricercata'' was used as a test case. Here, each new part of the piece was followed by an increase of the fractal dimension because of the increase of information at the part changes. The second piece ``Galamb borong,'' number seven of the piano Etudes was used, because Ligeti wrote these Etudes after studying fractal geometry. Although the piece is not fractal in the strict mathematical sense, the overall structure of the psychoacoustic event-density as well as the detailed event development is represented by the fractal dimension plot.

  15. Comparison of external and internal implant-abutment connections for implant supported prostheses. A systematic review and meta-analysis.

    Science.gov (United States)

    Lemos, Cleidiel Aparecido Araujo; Verri, Fellippo Ramos; Bonfante, Estevam Augusto; Santiago Júnior, Joel Ferreira; Pellizzer, Eduardo Piza

    2018-03-01

    The systematic review and meta-analysis aimed to answer the PICO question: "Do patients that received external connection implants show similar marginal bone loss, implant survival and complication rates as internal connection implants?". Meta-analyses of marginal bone loss, survival rates of implants and complications rates were performed for the included studies. Study eligibility criteria included (1) randomized controlled trials (RCTs) and/or prospective, (2) studies with at least 10 patients, (3) direct comparison between connection types and (4) publications in English language. The Cochrane risk of bias tool was used to assess the quality and risk of bias in RCTs, while Newcastle-Ottawa scale was used for non-RCTs. A comprehensive search strategy was designed to identify published studies on PubMed/MEDLINE, Scopus, and The Cochrane Library databases up to October 2017. The search identified 661 references. Eleven studies (seven RCTs and four prospective studies) were included, with a total of 530 patients (mean age, 53.93 years), who had received a total of 1089 implants (461 external-connection and 628 internal-connection implants). The internal-connection implants exhibited lower marginal bone loss than external-connection implants (PInternal connections had lower marginal bone loss when compared to external connections. However, the implant-abutment connection had no influence on the implant's survival and complication rates. Based on the GRADE approach the evidence was classified as very low to moderate due to the study design, inconsistency, and publication bias. Thus, future research is highly encouraged. Internal connection implants should be preferred over external connection implants, especially when different risk factors that may contribute to increased marginal bone loss are present. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. EXPERIMENTAL RESEARCH OF REGENERATIVE FEATURES IN BONE TISSUES AROUND IMPLANTS AFTER ONE-STAGE BILATERAL TOTAL HIP REPLACEMENT

    Directory of Open Access Journals (Sweden)

    V. M. Mashkov

    2012-01-01

    Full Text Available Objective: to research the specific features of regenerative processes of bone tissue around implants after one-stage bilateral total hip replacement in experiment. Material and methods: 27 total hip replacement operations have been performed in 18 rabbits of breed "chinchilla" to which bipolar femoral endoprosthesis made of titanic alloy PT-38, one type-size, with friction pair metal-on-metal and neck-shaft angle 165 degrees have been implanted: total unilateral hip replacement operations have been performed in 9 animals (control group, one-stage bilateral total hip replacement operations have been performed in 9 animals (experimental group. During research they have been on radiological and clinical checking-up. After the experiment the animals had histological tests of the tissues around endoprosthesis components. Results and conclusions: After one-stage bilateral total hip replacement in early terms of research more expressed changes of bone tissue in the form of its thinning and decompaction were found around implants. One-stage bilateral total hip replacement did not essentially influence on the speed of osteogenesis around endoprothesis components in comparison with unilateral total hip replacement, so in late terms of observation in both groups the fixing of endoprothesis components did not differ.

  17. Radial support device for the bundle wrapper and the tube support plates of a steam generator by eccentric stops

    International Nuclear Information System (INIS)

    Comic, G.

    1995-01-01

    Each stop consists of a first piece fixed to the bundle wrapper and in contact to the interior wall of the casing and able to slide with respect to it. A second piece is supported rigidly on the plates and is movably supported on the first piece, movement being possible radially between a first position and a second position corresponding to contact with the plate. A third piece equipped with a cam moves the second piece between its two positions. 5 figs

  18. Axial displacement of external and internal implant-abutment connection evaluated by linear mixed model analysis.

    Science.gov (United States)

    Seol, Hyon-Woo; Heo, Seong-Joo; Koak, Jai-Young; Kim, Seong-Kyun; Kim, Shin-Koo

    2015-01-01

    To analyze the axial displacement of external and internal implant-abutment connection after cyclic loading. Three groups of external abutments (Ext group), an internal tapered one-piece-type abutment (Int-1 group), and an internal tapered two-piece-type abutment (Int-2 group) were prepared. Cyclic loading was applied to implant-abutment assemblies at 150 N with a frequency of 3 Hz. The amount of axial displacement, the Periotest values (PTVs), and the removal torque values(RTVs) were measured. Both a repeated measures analysis of variance and pattern analysis based on the linear mixed model were used for statistical analysis. Scanning electron microscopy (SEM) was used to evaluate the surface of the implant-abutment connection. The mean axial displacements after 1,000,000 cycles were 0.6 μm in the Ext group, 3.7 μm in the Int-1 group, and 9.0 μm in the Int-2 group. Pattern analysis revealed a breakpoint at 171 cycles. The Ext group showed no declining pattern, and the Int-1 group showed no declining pattern after the breakpoint (171 cycles). However, the Int-2 group experienced continuous axial displacement. After cyclic loading, the PTV decreased in the Int-2 group, and the RTV decreased in all groups. SEM imaging revealed surface wear in all groups. Axial displacement and surface wear occurred in all groups. The PTVs remained stable, but the RTVs decreased after cyclic loading. Based on linear mixed model analysis, the Ext and Int-1 groups' axial displacements plateaued after little cyclic loading. The Int-2 group's rate of axial displacement slowed after 100,000 cycles.

  19. Pressure distribution of implant-supported removable partial dentures with stress-breaking attachments.

    Science.gov (United States)

    Kono, Kentaro; Kurihara, Daisuke; Suzuki, Yasunori; Ohkubo, Chikahiro

    2014-04-01

    This in vitro study investigated the pressure distribution of the implant-supported removable partial dentures (RPDs) with the stress-breaking attachments under the occlusal force. The experimental model of bilateral missing premolars and molars was modified from a commercial simulation model. Five pressure sensors were embedded near the bilateral first molars, first premolars, and medio-lingual alveolar crest. Two implants were placed near the second molars, and they were connected to the denture base using the following conditions: complete separation between the denture base and implant with cover screws (CRPD), flexible connection with a stress-breaking ball (SBB) attachment, and rigid connection without stress breaking with healing caps (HC). The pressure at five different areas of the soft tissue and the displacement of the RPDs were simultaneously measured, loading up to 50 N. The coefficient of variation (CV) for each connection was calculated from all data of the pressure at five areas to evaluate the pressure distribution. The pressure on medio-lingual alveolar crest and molars of the HC was less than SBB and CRPD. In contrast, the pressure on premolars of SBB was greater than for the HC and CRPD. The CV of SBB was less than that of HC and CRPD. Denture displacement of HC and SBB was less than for CRPD. Within the in vitro limitations, precise denture settlements and pressure distribution under the denture base could be controlled using an SBB attachment. An SBB attachment might be able to protect the implant from harmful force. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  20. Manufacturing and thermomechanical testing of actively cooled all beryllium high heat flux test pieces

    International Nuclear Information System (INIS)

    Vasiliev, N.N.; Sokolov, Yu.A.; Shatalov, G.E.

    1995-01-01

    One of the problems affiliated to ITER high heat flux elements development is a problem of interface of beryllium protection with heat sink routinely made of copper alloys. To get rid of this problem all beryllium elements could be used as heat receivers in places of enhanced thermal loads. In accordance with this objectives four beryllium test pieces of two types have been manufactured in open-quotes Institute of Berylliumclose quotes for succeeding thermomechanical testing. Two of them were manufactured in accordance with JET team design; they are round open-quotes hypervapotron typeclose quotes test pieces. Another two ones are rectangular test sections with a twisted tape installed inside of the circular channel. Preliminary stress-strain analysis have been performed for both type of the test pieces. Hypervapotrons have been shipped to JET where they were tested on JET test bed. Thermomechanical testing of pieces of the type of open-quotes swirl tape inside of tubeclose quotes have been performed on Kurchatov Institute test bed. Chosen beryllium grade properties, some details of manufacturing, results of preliminary stress-strain analysis and thermomechanical testing of the test pieces open-quotes swirl tape inside of tubeclose quotes type are given in this report

  1. Use of an Implant O-Ring Attachment for the Tooth Supported Mandibular Overdenture: A Clinical Report

    Science.gov (United States)

    Guttal, Satyabodh S.; Tavargeri, Anand K.; Nadiger, Ramesh K.; Thakur, Srinath L.

    2011-01-01

    Retention of a mandibular denture can be achieved by an implant-retained or natural tooth-retained bar and stud attachment in the anterior segment of the mandible. The same design principles holds true for both implant-retained and tooth-retained methods of anchoring the bar and stud attachment. A simple and cost effective treatment for more complex implant overdenture is the concept of conventional tooth-retained overdentures. When few firm teeth still remain in a compromised dentition, preservation of these teeth for overdentures can improve retention and stability. The authors present a clinical report of a patient treated with a mandibular tooth-borne overdenture with bar and O-ring attachment. A splinted bar supported the prosthesis and an O-ring retained the denture. PMID:21769276

  2. Use of an implant o-ring attachment for the tooth supported mandibular overdenture: a clinical report.

    Science.gov (United States)

    Guttal, Satyabodh S; Tavargeri, Anand K; Nadiger, Ramesh K; Thakur, Srinath L

    2011-07-01

    Retention of a mandibular denture can be achieved by an implant-retained or natural tooth-retained bar and stud attachment in the anterior segment of the mandible. The same design principles holds true for both implant-retained and tooth-retained methods of anchoring the bar and stud attachment. A simple and cost effective treatment for more complex implant overdenture is the concept of conventional tooth-retained overdentures. When few firm teeth still remain in a compromised dentition, preservation of these teeth for overdentures can improve retention and stability. The authors present a clinical report of a patient treated with a mandibular tooth-borne overdenture with bar and O-ring attachment. A splinted bar supported the prosthesis and an O-ring retained the denture.

  3. Clinical and patient-reported outcomes of zirconia-based implant fixed dental prostheses: Results of a prospective case series 5 years after implant placement.

    Science.gov (United States)

    Spies, Benedikt Christopher; Witkowski, Siegbert; Vach, Kirstin; Kohal, Ralf-Joachim

    2018-01-01

    To evaluate the clinical and patient-reported outcome of all-ceramic zirconia implant supported fixed dental prostheses (FDPs) 5 years after implant installation. Thirteen patients were treated with two terminally placed one-piece zirconia implants for a three-unit FDP each. The FDPs consisted of a CAD/CAM-fabricated zirconia framework over-pressed with a fluor-apatite veneering ceramic and were adhesively cemented. Survival and success were assessed by applying modified US Public Health Service (USPHS) criteria and preparation of Kaplan-Meier (KM) plots. Alpha and Bravo ratings were accepted for success (among others including small area veneer chippings and occlusal roughness), whereas Charlie ratings allowing for intra-oral correction (e.g., polishing) were accepted for survival. Furthermore, patient-reported outcome measures (PROMs) were analyzed with the help of visual analogue scales (VAS). Wilcoxon matched-pairs signed-rank test (USPHS criteria) and linear mixed models (PROMs) were used to evaluate time effects on response variables. All patients were available 61.8 ± 1.1 months after implant installation (53.6 ± 3.1 months after final prosthesis insertion). FDP survival was 100%. Significant incidence of veneer chipping (p = .0096) and occlusal roughness (p = .0019) was observed. Charlie rated extent of both phenomena resulted in a KM success estimate of 38.5% (95% CI: 14.1%-62.8%; seven FDPs with obvious roughness, three of them with extended veneer chipping). Compared with the pre-treatment assessments (30%-81% of satisfaction), all surveys at prosthetic delivery showed significantly improved VAS scores (66%-93%; p ≤ .038), except for speech (p = .341). Concerning function, esthetics and self-esteem, no decrease in satisfaction could be observed until the end of follow-up (90%-96%; p ≥ .057), whereas perception of sense (92%) and speech (95%) increased over time (p ≤ .030). Occurrence of technical complications did not correlate

  4. Peri-implant soft tissue and marginal bone adaptation on implant with non-matching healing abutments: micro-CT analysis.

    Science.gov (United States)

    Finelle, Gary; Papadimitriou, Dimitrios E V; Souza, André B; Katebi, Negin; Gallucci, German O; Araújo, Mauricio G

    2015-04-01

    To assess (i) the outcome of changing the horizontal-offset dimension on the peri-implant soft tissues and the crestal bone and (ii) the effect of different healing abutments (flared vs. straight) on the marginal peri-implant soft tissues and crestal bone. Two-piece dental implants diameters of 3.5 and 4.5 mm were placed at least 1 mm subcrestal in five beagle dogs. Three different investigational groups: (i) 3.5-mm-diameter implant with narrow healing abutment (3.5N), (ii) 4.5-mm-diameter implant with narrow healing abutment (4.5N), and (iii) 3.5-mm-diameter implant with wide healing abutment (3.5W), were assessed. After 4 months of healing, the vertical distance from the marginal crestal bone (MB) to the implant shoulder (IS); the vertical distance from the IS to the first bone-to-implant contact; and the horizontal distance of bone ingrowth on the implant platform were measured with a high-resolution micro-CT (Xradia MicroXCT-200 system). Implants with a narrow healing caps showed an interproximal MB located between 0 and 1 mm above the implant shoulder, while the 3.5W group exhibits a mean value -0.50 mm. As all implants in group 3.5N presented a fBIC located at the level of the IS. For the 4.5N group, the mean fBIC-IS distance was -0.52 mm apically to the IS. For the 3.5WC group, the mean fBIC-IS distance was -1.42 mm. Horizontal bone apposition was only observed for the 3.5N group and the 4.5N group. The dimension of the horizontal offset would play a minimal role in reducing bone remodeling, whereas the configuration of the transmucosal component would directly influence marginal bone remodeling. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Extended and quasi-continuous tuning of quantum cascade lasers using superstructure gratings and integrated heaters

    Energy Technology Data Exchange (ETDEWEB)

    Bidaux, Yves, E-mail: yves.bidaux@alpeslasers.ch [Alpes Lasers SA, 1-3 Passsage Max Meuron, CH-2001 Neuchâtel (Switzerland); Institute for Quantum Electronics, ETH-Zurich, CH-8093 Zurich (Switzerland); Bismuto, Alfredo, E-mail: alfredo.bismuto@alpeslasers.ch; Tardy, Camille; Terazzi, Romain; Gresch, Tobias; Blaser, Stéphane; Muller, Antoine [Alpes Lasers SA, 1-3 Passsage Max Meuron, CH-2001 Neuchâtel (Switzerland); Faist, Jerome [Institute for Quantum Electronics, ETH-Zurich, CH-8093 Zurich (Switzerland)

    2015-11-30

    In this work, we demonstrate broad electrical tuning of quantum cascade lasers at 9.25 μm, 8.5 μm, and 4.4 μm in continuous wave operation using Vernier-effect distributed Bragg reflectors based on superstructure gratings. Integrated micro-heaters allow to switch from one Vernier channel to the other, while predictable and mode-hop free tuning can be obtained in each channel modulating the laser current with a side mode suppression ratio as high as 30 dB. The resulting device behaves effectively as a switchable multicolour tunable source. Tuning up to 6.5% of the central wavelength is observed. To prove the importance of the developed devices for high resolution molecular spectroscopy, a N{sub 2}O absorption spectrum has been measured.

  6. Loading Variables on Implant-Supported Distal-Extension Removable Partial Dentures: An In Vitro Pilot Study.

    Science.gov (United States)

    Hirata, Kiyotaka; Takahashi, Toshihito; Tomita, Akiko; Gonda, Tomoya; Maeda, Yoshinobu

    2016-01-01

    The aim of this study was to investigate strain on implants used for adjunctive support of distal extension removable partial dentures. An implant with strain gauges was used for testing purposes in two positions, parallel and inclined. Three loading scenarios--loading apparatus (LA), artificial teeth via cotton roll (CR), and artificial teeth (UT)--were studied and strains compared via the Kruskal-Wallis test (P=.05). Strain under CR was significantly larger than UT in parallel (P<.05). However, the opposite was observed in inclined. Strain in parallel was smallest for UT, whereas in inclined it was largest for CR.

  7. The Effect of Abutment Surface Roughness on the Retention of Implant-Supported Crowns Cemented with Provisional

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Abrisham

    2012-09-01

    Full Text Available Introduction: Surface roughness can increase the retention of castings by ridges and grooves that are microretentive. This study compared the retention of implant-supported crowns when used with 3 different surface roughness abutments and one temporary cement. Methods: Thirty solid abutments (ITI, 4 mm high, were divided into three groups randomly. In the first group, 10 abutments were roughened with sandblast (50-µm aluminum oxide and in the second group, 10 abutments were roughened with diamond bur. The third group had no surface treatment. Then, thirty implant fixture analogs (ITI were placed in the center of acrylic cylinders. After that a solid abutment was tightened on the each fixture analog with 35 N/cm force. Thirty base metal crowns were made on the 4 mm ITI abutment analogs using plastic coping. The prepared copings were cemented on the abutments by TempBond temporary cement and finally, crowns were pulled from the abutment in a universal test machine at a cross speed of 0.5cm/min. Results: The mean tensile strength in sandblasted, bur treated, and control group were 64.38±8, 91.37±7.19, and 58.61±1.93, respectively. Bur treated group showed higher tensile strength in comparison with two other groups. Conclusion: Surface modification of implant abutment by diamond bur may be an effective method to increase retention of crown when TempBond is used.

  8. Y-piece temperature and humidification during mechanical ventilation.

    Science.gov (United States)

    Solomita, Mario; Daroowalla, Feroza; Leblanc, Deniese S; Smaldone, Gerald C

    2009-04-01

    Practitioners often presume there is adequate humidification in the ventilator circuit if the Y-piece is at a specified temperature, but control of Y-piece temperature may be inadequate to ensure adequate humidification. In an in vitro bench model we measured water-vapor delivery with several heated humidification setups and a wide range of minute volume (V (E)) values. The setup included a condenser, hygrometry, and thermometer. First, we calibrated the system with a point-source humidifier and water pump. Then we tested the water-vapor delivery during non-heated-wire humidification and during heated-wire humidification with a temperature gradient of +3 degrees C, 0 degrees C, and -3 degrees C between the humidifier and the Y-piece. We compared the results to 2 recommended humidification values: 100% saturated (absolute humidity 44 mg H(2)O/L) gas at 37 degrees C (saturated/37 degrees C); and 75% saturated (absolute humidity 33 mg H(2)O/L), which is the humidity recommended by the International Organization for Standardization (the ISO standard). In all the experiments the setup was set to provide 35 degrees C at the Y-piece. Our method for measuring water-vapor delivery closely approximated the amount delivered by a calibrated pump, but slightly underestimated the water-vapor delivery in all the experiments and the whole V (E) range. At all V (E) values, water-vapor delivery during non-heated-wire humidification matched or exceeded saturated/37 degrees C and was significantly greater than that during heated-wire humidification. During heated-wire humidification, water-vapor delivery varied with the temperature gradient and did not reach saturated/37 degrees C at V (E) > 6 L/min. Water-vapor delivery with the negative temperature gradient was below the ISO standard. Maintaining temperature at one point in the inspiratory circuit (eg, Y-piece), does not ensure adequate water-vapor delivery. Other factors (humidification system, V (E), gradient setting) are critical

  9. A bio-inspired N-doped porous carbon electrocatalyst with hierarchical superstructure for efficient oxygen reduction reaction

    Science.gov (United States)

    Miao, Yue-E.; Yan, Jiajie; Ouyang, Yue; Lu, Hengyi; Lai, Feili; Wu, Yue; Liu, Tianxi

    2018-06-01

    The bio-inspired hierarchical "grape cluster" superstructure provides an effective integration of one-dimensional carbon nanofibers (CNF) with isolated carbonaceous nanoparticles into three-dimensional (3D) conductive frameworks for efficient electron and mass transfer. Herein, a 3D N-doped porous carbon electrocatalyst consisting of carbon nanofibers with grape-like N-doped hollow carbon particles (CNF@NC) has been prepared through a simple electrospinning strategy combined with in-situ growth and carbonization processes. Such a bio-inspired hierarchically organized conductive network largely facilitates both the mass diffusion and electron transfer during the oxygen reduction reactions (ORR). Therefore, the metal-free CNF@NC catalyst demonstrates superior catalytic activity with an absolute four-electron transfer mechanism, strong methanol tolerance and good long-term stability towards ORR in alkaline media.

  10. Influence of artificial aging on the load-bearing capability of straight or angulated zirconia abutments in implant/tooth-supported fixed partial dentures.

    Science.gov (United States)

    Nothdurft, Frank P; Doppler, Klaus E; Erdelt, Kurt J; Knauber, Andreas W; Pospiech, Peter R

    2010-01-01

    The aim of the study was to evaluate the influence of artificial aging on the fracture behavior of straight and angulated zirconia implant abutments used in ZirDesign (Astra Tech) implant/tooth-supported fixed partial dentures (FPDs) in the maxilla. Four different test groups (n = 8) representing anterior implant/tooth-supported FPDs were prepared. Groups 1 and 2 simulated a clinical situation with an ideal implant position (maxillary left central incisor) from a prosthetic point of view, which allowed for the use of a straight, prefabricated zirconia abutment. Groups 3 and 4 simulated a situation with a compromised implant position that required an angulated (20-degree) abutment. OsseoSpeed implants (4.5 3 13 mm, Astra Tech) as well as metal tooth analogs (maxillary right lateral incisor) with simulated periodontal mobility were mounted in polymethyl methacrylate. The FPDs (chromium-cobalt alloy) were cemented with glass ionomer. Groups 2 and 4 were thermomechanically loaded and subjected to static loading until failure. Statistical analysis of force data at the fracture site was performed using nonparametric tests. All samples survived thermomechanical loading. Artificial aging did not lead to a significant decrease in load-bearing capacity in either the straight abutments or the angulated abutments. The restorations that used angulated abutments exhibited higher fracture loads than the restorations with straight abutments (group 1: 209.13 ± 39.11 N; group 2: 233.63 ± 30.68 N; group 3: 324.62 ± 108.07 N; group 4: 361.75 ± 73.82 N). This difference in load-bearing performance was statistically significant, both with and without artificial aging. All abutment fractures occurred below the implant shoulder. Compensation for angulated implant positions with an angulated zirconia abutment is possible without reducing the load-bearing capacity of implant/tooth-supported anterior FPDs.

  11. Maintenance of marginal bone support and soft tissue esthetics at immediately provisionalized OsseoSpeed implants placed into extraction sites: 2-year results.

    Science.gov (United States)

    Noelken, Robert; Neffe, Bettina Anna; Kunkel, Martin; Wagner, Wilfried

    2014-02-01

    Placement of implants into extraction sockets targets the maintenance of peri-implant hard and soft tissue structures and the support of a natural and esthetic contour. The main advantages of immediate implant insertion in comparison with delayed implant placement protocols are as follows: a reduced treatment time, less number of sessions, and, thus, the less invasive procedure. This study examines the clinical performance (survival rate, marginal bone levels and Pink Esthetic Score [PES]) of OsseoSpeed implants placed into extraction sockets with immediate provisionalization in the anterior maxilla after a follow-up of at least 12 months. Twenty patients received a total number of 37 OsseoSpeed implants which were immediately inserted into extraction sockets with or without facial bone deficiencies of various dimensions. A flapless procedure was applied, and the implants were immediately provisionalized with temporary crowns without occlusal contacts. Facial gaps between implant surface and facial bone or the previous contour of the alveolar process were grafted with autogenous bone chips. Implants in diameters 3.5, 4.0, 4.5, and 5.0 with lengths of 11-17 mm were used in the study. During the course of the study, interproximal marginal bone levels, the thickness of the facial bony wall, implant success rate according to the criteria established by Buser, and the PES were assessed per implant. One patient with three implants did not continue the study after prosthesis delivery, the remaining 34 implants were still in function at the final follow-up (survival rate: 100%). The mean follow-up period was 27 months (range, 12-40 months). Marginal bone height at the level of the implant shoulder averaged -0.1 ± 0.55 mm (range, -1.25 to 1.47 mm) at the final follow-up. The mean PES ratings were 11.3 ± 1.8 (range, 6-14) at the final follow-up. In 78% of the patients, the PES was preserved or even improved. Success rates, marginal bone levels, and esthetic results suggest

  12. Hierarchical super-structure identified by polarized light microscopy, electron microscopy and nanoindentation: Implications for the limits of biological control over the growth mode of abalone sea shells

    Directory of Open Access Journals (Sweden)

    Schneider Andreas S

    2012-09-01

    Full Text Available Abstract Background Mollusc shells are commonly investigated using high-resolution imaging techniques based on cryo-fixation. Less detailed information is available regarding the light-optical properties. Sea shells of Haliotis pulcherina were embedded for polishing in defined orientations in order to investigate the interface between prismatic calcite and nacreous aragonite by standard materialographic methods. A polished thin section of the interface was prepared with a defined thickness of 60 μm for quantitative birefringence analysis using polarized light and LC-PolScope microscopy. Scanning electron microscopy images were obtained for comparison. In order to study structural-mechanical relationships, nanoindentation experiments were performed. Results Incident light microscopy revealed a super-structure in semi-transparent regions of the polished cross-section under a defined angle. This super-structure is not visible in transmitted birefringence analysis due to the blurred polarization of small nacre platelets and numerous organic interfaces. The relative orientation and homogeneity of calcite prisms was directly identified, some of them with their optical axes exactly normal to the imaging plane. Co-oriented "prism colonies" were identified by polarized light analyses. The nacreous super-structure was also visualized by secondary electron imaging under defined angles. The domains of the super-structure were interpreted to consist of crystallographically aligned platelet stacks. Nanoindentation experiments showed that mechanical properties changed with the same periodicity as the domain size. Conclusions In this study, we have demonstrated that insights into the growth mechanisms of nacre can be obtained by conventional light-optical methods. For example, we observed super-structures formed by co-oriented nacre platelets as previously identified using X-ray Photo-electron Emission Microscopy (X-PEEM [Gilbert et al., Journal of the

  13. Effect of tightening torque on the marginal adaptation of cement-retained implant-supported fixed dental prostheses.

    Science.gov (United States)

    Ghanbarzadeh, Jalil; Dashti, Hossin; Karamad, Reza; Alikhasi, Marzieh; Nakhaei, Mohammadreza

    2015-01-01

    The final position of the abutment changes with the amount of tightening torque. This could eventually lead to loss of passivity and marginal misfit of prostheses. The aim of this study was to evaluate the effect of three different tightening torques on the marginal adaptation of 3-unit cement-retained implant-supported fixed dental prostheses (FDPs). Two implants (Straumann) were inserted in an acrylic block so that one of the implants was placed vertically and the other at a 15° vertical angle. A straight abutment and a 15° angulated abutment were connected to the vertically and obliquely installed implants, respectively, so that the two abutments were parallel. Then, 10 cement-retained FDPs were waxed and cast. Abutments were tightened with 10, 20, and 35 Ncm torques, respectively. Following each tightening torque, FDPs were luted on respective abutments with temporary cement. The marginal adaptation of the retainers was evaluated using stereomicroscope. FDPs were then removed from the abutments and were sectioned at the connector sites. The retainers were luted again on their respective abutments. Luting procedures and marginal adaptation measurement were repeated. Data were analyzed by ANOVA and least significant difference tests (α = 0.05). After cutting the FDP connectors, the independent samples t-test was used to compare misfit values (α = 0.05). Following 10, 20, and 35 Ncm tightening torques, the marginal discrepancy of the retainers of FDPs significantly increased (P marginal discrepancies of these two retainers (P > 0.05). The marginal gap values of angulated abutment retainers (ANRs) were significantly higher than those of the straight abutment after cutting the connectors (P = 0.026). Within the limitations of this study, the marginal misfit of cement-retained FDPs increased continuously when the tightening torque increased. After cutting the connectors, the marginal misfit of the ANRs was higher than those of the straight abutment retainers.

  14. Bacterial colonization of the implant-abutment interface of conical connection with an internal octagon: an in vitro study using real-time PCR.

    Science.gov (United States)

    Baj, A; Beltramini, G A; Bolzoni, A; Cura, F; Palmieri, A; Scarano, A; Ottria, L; Giannì, A B

    2017-01-01

    Bacterial leakage at the implant-abutment connection of a two-piece implant system is considered the main cause of peri-implantitis. Prevention of bacterial leakage at the implant-abutment connection is mandatory for reducing inflammation process around implant neck and achieving bone stability. Micro-cavities at implant-abutment connection level can favour bacterial leakage, even in modern two-piece implant systems. The conical connection with an internal octagon (CCIO) is considered to be more stable mechanically and allows a more tight link between implant and abutment. As P. gingivalis and T. forsythia penetration might have clinical relevance, it was the purpose of this investigation to evaluate molecular leakage of these two bacteria in a new two-implant system with an internal conical implant-abutment connection with internal octagon (Shiner XT, FMD Falappa Medical Devices S.p.A. Rome, Italy). To verify the ability of the implant in protecting the internal space from the external environment, the passage of genetically modified Escherichia c oli across implant-abutment interface was evaluated. Four Shiner XT implants (FMD, Falappa Medical Devices®, Rome, Italy) were immerged in a bacterial culture for 24 h and bacteria amount was measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 6% for P. gingivalis and 5% for T. forsythia. Other comparable studies about the tightness of the tested implant system reported similar results. The gap size at the implant-abutment connection of CCIOs was measured by other authors discovering a gap size of 1–2μm of the AstraTech system and of 4μm for the Ankylos system. Bacterial leakage along implant-abutment connection of cylindrical and tapered implants, Shiner XT, (FMD Falappa Medical Devices S.p.A. Rome, Italy) showed better results compared to other implants. Additional studies are needed to explore the relationship in terms of

  15. Motor behavior during the first chewing cycle in subjects with fixed tooth- or implant-supported prostheses.

    Science.gov (United States)

    Grigoriadis, Joannis; Trulsson, Mats; Svensson, Krister G

    2016-04-01

    Appropriate sensory information from periodontal mechanoreceptors (PMRs) is important for optimizing the positioning of food and adjustment of force vectors during precision biting. This study was designed to describe motor behavior during the first cycle of a natural chewing task and to evaluate the role of such sensory input in this behavior. While 10 subjects with natural dentition, 11 with bimaxillary fixed tooth-supported prostheses (TSP) and 10 with bimaxillary fixed implant-supported prostheses (ISP) (mean age 69 [range 61-83]) chewed a total of five hazelnuts, their vertical and lateral jaw movements were recorded. Data obtained during the first chewing cycle of each hazelnut were analyzed. The amplitude of vertical and lateral mandibular movement and duration of jaw opening did not differ between the groups, indicating similar behavior during this part of the chewing cycle. However, only 30% of the subjects in the natural dentate group, but 82% of those in the TSP and 70% in the ISP group exhibited slippage of the hazelnut during jaw closure in at least one of five trials. The TSP and ISP groups also exhibited more irregular and narrower patterns of motion (total lateral/vertical movement = 0.15 and 0.19, respectively, compared to 0.27 for the natural group). Subjects with fixed tooth- or implant-supported prostheses in both jaws show altered behavior, including inadequate control of the hazelnut, during the first chewing cycle. We propose that these differences are due to impairment or absence of sensory signaling from PMRs in these individuals. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Staged Hard and Soft Tissue Reconstruction Followed by Implant Supported Restoration in the Aesthetic Zone: A Case Report.

    Science.gov (United States)

    Parthasarathy, Harinath; Ramachandran, Lakshmi; Tadepalli, Anupama; Ponnaiyan, Deepa

    2017-04-01

    Alveolar ridge deficiency is a common clinical consequence following tooth loss due to chronic periodontitis complicating ideal implant placement. Advanced hard and soft tissue augmentation procedures have been developed in the recent past with predictable clinical outcomes. A male patient presented with a Grade III mobile upper right central incisor associated with advanced bone loss and soft tissue deficit. Following extraction of tooth #11, socket augmentation was done using an autogenous cortico-cancellous block graft and subsequent soft tissue augmentation was done with palatal connective tissue graft. At the end of six months, a tapered self tapping implant fixture was placed with adequate primary stability and after eight weeks, second stage implant surgery was done with the Misch technique in order to recreate papillae and the implant was prosthetically restored. The alveolar ridge was adequately recontoured following the staged surgical protocol. The implant was well integrated at the end of 15 months. Execution of sequential surgical procedures in a highly deficient edentulous site made it possible to achieve of optimal pink and white aesthetics with stable implant supported fixed prosthesis.

  17. [Influence of coping material selection and porcelain firing on marginal and internal fit of computer-aided design/computer- aided manufacturing of zirconia and titanium ceramic implant-supported crowns].

    Science.gov (United States)

    Cuiling, Liu; Liyuan, Yang; Xu, Gao; Hong, Shang

    2016-06-01

    This study aimed to investigate the influence of coping material and porcelain firing on the marginal and internal fit of computer-aided design/computer-aided manufacturing (CAD/CAM) of zirconia ceramic implant- and titanium ceramic implant-supported crowns. Zirconia ceramic implant (group A, n = 8) and titanium metal ceramic implant-supported crowns (group B, n = 8) were produced from copings using the CAD/CAM system. The marginal and internal gaps of the copings and crowns were measured by using a light-body silicone replica technique combined with micro-computed tomography scanning to obtain a three-dimensional image. Marginal gap (MG), horizontal marginal discrepancy (HMD), and axial wall (AW) were measured. Statistical analyses were performed using SPSS 17.0. Prior to porcelain firing, the measurements for MG, HMD, and AW of copings in group A were significantly larger than those in group B (P 0.05). Porcelain firing significantly reduced MG (P 0.05). The marginal fits of CAD/CAM zirconia ceramic implant-supported crowns were superior to those of CAD/CAM titanium ceramic-supported crowns. The fits of both the CAD/CAM zirconia ceramic implant- and titanium ceramic implant-supported crowns were obviously influenced by porcelain firing.

  18. Sutureless, Glueless, Scleral Fixation of Single-Piece and Toric Intraocular Lens: A Novel Technique

    Directory of Open Access Journals (Sweden)

    Aditya Kelkar

    2015-07-01

    Full Text Available Sutureless, glueless, scleral fixation of an intraocular lens is a known technique of fixing a lens in the scleral pockets. However, this technique is applied to single-piece and toric lenses instead of 3-piece lenses, allowing the advantage of the use of premium lenses in patients with poor capsular support. Favourable results without complications of pigment dispersion, iris transillumination defects, dysphotopsia, elevated intraocular pressure, intraocular hemorrhage and cystoid macular edema with a well-centered, stable intraocular lens have been observed in the 3-month postoperative period in both cases.

  19. Fracture load of complete-arch implant-supported prostheses reinforced with nylon-silica mesh: An in vitro study.

    Science.gov (United States)

    Gonçalves, Fernanda de Cássia Papaiz; Amaral, Marina; Borges, Alexandre Luiz Souto; Gonçalves, Luiz Fernando Martins; Paes-Junior, Tarcisio José de Arruda

    2018-04-01

    Complete-arch implant-supported prostheses without a framework have a high risk of failure: a straightforward and inexpensive reinforcement material, such as nylon mesh, could improve their longevity. The purpose of this in vitro study was to evaluate a nylon-silica mesh compound on the fracture strength of acrylic resin and the fracture load of complete-arch implant-supported prostheses. Twenty-four complete mandibular arch implant-supported prostheses were divided into 2 groups according to cantilever length (molar and premolar) and subdivided into another 2 subgroups according to the presence or absence of reinforcing mesh. The specimens were submitted to a maximum load-to-fracture test in a universal testing machine, with a 100-N load cell, a 2 mm/min crosshead speed, and a spherical metal tip diameter of 4 mm at different points (molar and premolar). These were submitted to 1-way analysis of variance for repeated measurement and the post hoc Tukey multiple comparison test (α=.05). The mean maximum load ±standard deviation for the molar group was 393.4 ±95.0 N with reinforcement and 305.4 ±76.3 N without reinforcement (P=.02); and for the premolar group was 1083.3 ±283.7 N with reinforcement and 605.3 ±90.5 N without reinforcement (P=.001). Reinforcement with nylon mesh increased the mean maximum load of implant-supported complete-arch prostheses at both cantilever lengths. The cantilever to the premolar (5 mm) presented the highest maximum load values to fracture. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  20. Immediate Direct-To-Implant Breast Reconstruction Using Anatomical Implants

    Directory of Open Access Journals (Sweden)

    Sung-Eun Kim

    2014-09-01

    Full Text Available BackgroundIn 2012, a new anatomic breast implant of form-stable silicone gel was introduced onto the Korean market. The intended use of this implant is in the area of aesthetic breast surgery, and many reports are promising. Thus far, however, there have been no reports on the use of this implant for breast reconstruction in Korea. We used this breast implant in breast reconstruction surgery and report our early experience.MethodsFrom November 2012 to April 2013, the Natrelle Style 410 form-stable anatomically shaped cohesive silicone gel-filled breast implant was used in 31 breasts of 30 patients for implant breast reconstruction with an acellular dermal matrix. Patients were treated with skin-sparing mastectomies followed by immediate breast reconstruction.ResultsThe mean breast resection volume was 240 mL (range, 83-540 mL. The mean size of the breast implants was 217 mL (range, 125-395 mL. Breast shape outcomes were considered acceptable. Infection and skin thinning occurred in one patient each, and hematoma and seroma did not occur. Three cases of wound dehiscence occurred, one requiring surgical intervention, while the others healed with conservative treatment in one month. Rippling did not occur. So far, complications such as capsular contracture and malrotation of breast implant have not yet arisen.ConclusionsBy using anatomic breast implants in breast reconstruction, we achieved satisfactory results with aesthetics better than those obtained with round breast implants. Therefore, we concluded that the anatomical implant is suitable for breast reconstruction.

  1. Development of patient-based questionnaire about aesthetic and functional differences between overdentures implant-supported and overdentures tooth-supported. Study of 43 patients with a follow up of 1 year

    OpenAIRE

    GARGARI, M.; PRETE, V.; PUJIA, M.; CERUSO, F. M.

    2013-01-01

    Development of patient-based questionnaire about aesthetic and functional differences between overdentures implant-supported and overdentures tooth-supported. Study of 43 patients with a follow up of 1 year.

  2. Product management of making large pieces through Rapid Prototyping PolyJet® technology

    Science.gov (United States)

    Belgiu, G.; Cărăuşu, C.; Şerban, D.; Turc, C. G.

    2017-08-01

    The rapid prototyping process has already become a classic manufacturing process for parts and assemblies, either polymeric or metal parts. Besides the well-known advantages and disadvantages of the process, the use of 3D printers has a great inconvenience: the overall dimensions of the parts are limited. Obviously, there is a possibility to purchase a larger (and more expensive) 3D printer, but there are always larger pieces to be manufactured. One solution to this problem is the splitting of parts into several components that can be manufactured. The component parts can then be assembled in a single piece by known methods such as welding, gluing, screwing, etc. This paper shows our experience in making large pieces on the Strarasys® Objet24 printer, pieces larger than the tray sizes. The results obtained are valid for any 3D printer using the PolyJet® process.

  3. Stress analysis on the free-end distal extension of an implant-supported mandibular complete denture

    Directory of Open Access Journals (Sweden)

    Gustavo Diniz Greco

    2009-06-01

    Full Text Available A comparative and qualitative analysis of the tensions generated in the cantilever region of an implant-supported mandibular complete denture was conducted using the three-dimensional finite element method. The mechanical properties of the components were input in the model and a load of 15 N was applied in pre-determined points. In the first simulation, the load was applied on the occlusal surface of the first premolar. In the second simulation, it was applied on the first and second premolars. In the third simulation, it was applied on the first and second premolars and on the first molar. The different occlusion patterns produced similar tension distributions in the cantilever region, which followed a similar pattern in the three simulations. In all of the cases, the highest levels of tension were located in the region of the first implant. However, as the loads were dislocated distally, the tensions increased considerably. The more extensive the cantilever, the more compromised will be the infrastructure, the prosthetic components and the implants. Regardless of the length of the cantilever, the highest tensions will always be located in the region of the implant next to the load application point.

  4. Realistic dynamic stope support testing

    CSIR Research Space (South Africa)

    Ortlepp, WD

    2000-08-01

    Full Text Available -August 1999. Construction of the steel superstructure commenced early in November 1999 and was completed within two weeks. Progress in commissioning the portal crane and the main compressed air hoist was hampered by small design faults and lack...’ for innovative developments. In particular, techniques for preventing collapses between support units and over the work area between the front line of support and the stope face can be explored. There can be little doubt that the facility could also serve a...

  5. State of the Art of Short Dental Implants: A Systematic Review of the Literature

    DEFF Research Database (Denmark)

    Neldam, Camilla Albeck; Pinholt, Else Marie

    2012-01-01

    restorations, supporting overdentures, splinted implants, and implants used for prostheses. Results: The 27 included studies represent zero randomized clinical trial studies, 15 prospective nonrandomized, noncontrolled clinical trials, 11 retrospective nonrandomized, noncontrolled clinical trials, and one...

  6. Maintenance in dental implants

    Directory of Open Access Journals (Sweden)

    Giselle Póvoa Gomes

    2008-01-01

    Full Text Available In implants, maintenance is a decisive factor for obtaining success when implant supported overdentures and dentures are used. The present stud presents, a clinical case of a patient, a 70 year-old white man, with a completely edentulous mandibular alveolar ridge, severe bone resorption with presence of basal bone only, and absence of vestibule. Initially, treatment consisted of the placement of a mandibular overdenture, supported on three implants in the anterior inter-foramen region, as the left implant was transfixed in the basal bone of 2 to 3 millimeters. Eleven years later, another two implants were placed in the anterior area and an immediate load was performed up to the first molars, for the placement of an implant supported fixed. Throughout the entire treatment, meticulous maintenance was carried out, with follow-up for fourteen years, interrupted by the patient’s death. From the third month after the opening the three implants initially placed, the presence of keratinized mucosa, definition of the vestibule, maturation of the alveolar ridge and bone formation in the mento region were observed. It was concluded that good planning, allied to mastery of the technique and adequate maintenance were the prerequisites necessary for obtaining favorable results, success of the present case, and for the patient to have a better quality of life.

  7. Replacement of a hopeless maxillary central incisor: a technique for the fabrication of an immediate implant-supported interim restoration.

    Science.gov (United States)

    Graiff, Lorenzo; Vigolo, Paolo

    2012-04-01

    Placement of a dental implant and an interim restoration in the esthetic zone immediately following tooth extraction is now a common procedure. However, in such clinical situations, the fabrication of an appropriate interim restoration may be challenging. The aim of this article is to present a technique for modifying the extracted tooth so it can be used as an implant-supported interim restoration.

  8. Penile prosthesis implant: scientific advances and technological innovations over the last four decades.

    Science.gov (United States)

    Chung, Eric

    2017-02-01

    Despite introduction of oral phosphodiesterase type 5 inhibitors and intracavernosal vasoactive agents, penile prosthesis implant remains a relevant and desired option with sales of penile prostheses continue to stay high, as many men became refractory to medical therapy and/or seeking a more effective and permanent therapy. There are two types of penile prosthesis implants: inflatable and non-inflatable types, and the inflatable penile implants can be subdivided into single-, two- and three-piece devices. Non-inflatable penile prosthesis (non-IPP) may be referred to as semi-rigid rod or malleable prosthesis. IPP is considered a superior option to malleable prosthesis as it produces penile rigidity and flaccidity that closely replicates a normal penile erectile function. Since the introduction of IPP by Scott in 1973, surgical landscape for penile prosthesis implantation has changed dramatically. Advances in prosthesis design, device technologies and surgical techniques have made penile prosthesis implant a more natural, durable and reliable device. The following article reviews the scientific advances and technological innovation in modern penile prosthesis implants over the last four decades.

  9. [Systematic review and meta-analysis on the effect of implant supported overdentures on the oral health related quality of life of edentulous patients].

    Science.gov (United States)

    Zhang, S S; Zhang, Y; Di, P; Lin, Y

    2017-05-09

    Objective: To evaluate the effect of implant related treatment on the oral health related quality of life (OHRQoL) of edentulous patients. Methods: The CNKI, Wanfang database and Medline, EMBASE, Cochrane Library databases that include randomized clinical trials comparing implant supported overdentures with conventional complete denture for edentulous patients were retrived. Nine studies involving 769 cases were included and meta-analysis was conducted. Results: The standardized mean difference (SMD) of oral health impact profile (OHIP) score was 1.63 (95% CI: 1.25-2.02) and improved after implant related treatment, which was significantly better than the conventional complete denture (0.87, 95% CI: 0.54-1.20). Conclusions: Implant supported overdentures improved patient's OHRQoL and showed better performance compared to the overdentures complete dentures.

  10. Transition from failing dentition to full-arch fixed implant-supported prosthesis with a staged approach using removable partial dentures: a case series.

    Science.gov (United States)

    Cortes, Arthur Rodriguez Gonzalez; Cortes, Djalma Nogueira; No-Cortes, Juliana; Arita, Emiko Saito

    2014-06-01

    The present retrospective case series is aimed at evaluating a staged approach using a removable partial denture (RPD) as an interim prosthesis in treatment to correct a failing dentition until such time as a full-arch fixed implant-supported prosthesis may be inserted. Eight patients, who had undergone maxillary full-arch rehabilitation with dental implants due to poor prognosis of their dentitions, were analyzed. All treatment included initial periodontal therapy and a strategic order of extraction of hopeless teeth. An RPD supported by selected teeth rehabilitated the compromised arch during implant osseointegration. These remaining teeth were extracted prior to definitive prosthesis delivery. Advantages and drawbacks of this technique were also recorded for the cases presented. Among the advantages provided by the staged approach are simplicity of fabrication, low cost, and ease of insertion. Additionally, RPD tooth support prevented contact between the interim prosthesis and healing abutments, promoting implant osseointegration. The main drawbacks were interference with speech and limited esthetic results. Implant survival rate was 100% within a follow-up of at least 1 year. The use of RPDs as interim prostheses allowed for the accomplishment of the analyzed rehabilitation treatments. It is a simple treatment alternative for patients with a low smile line. © 2013 by the American College of Prosthodontists.

  11. Retention of implant-supported zirconium oxide ceramic restorations using different luting agents.

    Science.gov (United States)

    Nejatidanesh, Farahnaz; Savabi, Omid; Shahtoosi, Mojtaba

    2013-08-01

    The aim of this study was to evaluate the retention value of implant-supported zirconium oxide ceramic copings using different luting agents. Twenty ITI solid abutments of 5.5 mm height and ITI implant analogs were mounted vertically into autopolymerizing acrylic resin blocks. Ninety zirconium oxide copings (Cercon, Degudent) with a loop on the occlusal portion were made. All samples were airborne particle abraded with 110 μm Al₂O₃ and luted using different types of luting agents: resin cements (Clearfil SA, Panavia F2.0, Fuji Plus), conventional cements (Fleck's, Poly F, Fuji I), and temporary cements (Temp Bond, GC free eugenol, TempSpan) with a load of 5 Kg. (N = 10) All copings were incubated at 37°C for 24 h and conditioned in artificial saliva for 1 week, and thermal cycled for 5000 cycles 5-55°C with a 30-s dwell time. The dislodging force of the copings along the long axis of the implant-abutment complex was recorded using universal testing machine with 5 mm/min crosshead speed. Data were subjected to Kruskal-Wallis (α = 0.05) and Mann-Whitney tests with Bonferroni step down correction (α = 0.001). There was significant difference between the mean rank retention values of different luting agents (P zirconium oxide restorations. © 2011 John Wiley & Sons A/S.

  12. The effect of implant number and position on the stress behavior of mandibular implant retained overdentures: A three-dimensional finite element analysis.

    Science.gov (United States)

    Topkaya, Tolga; Solmaz, Murat Yavuz

    2015-07-16

    The present study evaluated the effects of ball anchor abutment attached to implants with a 4.30 mm diameter and 11 mm insert length on stress distribution in a patient without any remaining teeth in the lower jaw. In the study, the stress analysis was performed for five different configurations (2 with 4 implant-supported and 3 with 2 implant-supported) and three different loading types using ANSYS Workbench software. The stresses measured in the 4 implant-supported models were lower compared to the stresses measured in the 2 implant-supported models. The stresses on the implants intensified on the cervical region of the implants. When the effects of the loading sites on the stress were examined, the loading on the first molar tooth produced the highest stresses on the implants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Graphene Functionalized Scaffolds Reduce the Inflammatory Response and Supports Endogenous Neuroblast Migration when Implanted in the Adult Brain.

    Directory of Open Access Journals (Sweden)

    Kun Zhou

    Full Text Available Electroactive materials have been investigated as next-generation neuronal tissue engineering scaffolds to enhance neuronal regeneration and functional recovery after brain injury. Graphene, an emerging neuronal scaffold material with charge transfer properties, has shown promising results for neuronal cell survival and differentiation in vitro. In this in vivo work, electrospun microfiber scaffolds coated with self-assembled colloidal graphene, were implanted into the striatum or into the subventricular zone of adult rats. Microglia and astrocyte activation levels were suppressed with graphene functionalization. In addition, self-assembled graphene implants prevented glial scarring in the brain 7 weeks following implantation. Astrocyte guidance within the scaffold and redirection of neuroblasts from the subventricular zone along the implants was also demonstrated. These findings provide new functional evidence for the potential use of graphene scaffolds as a therapeutic platform to support central nervous system regeneration.

  14. A 2D panoramic surgical stent imaging: Complete arch mandibular implant fixed prosthesis along with bar supported maxillary over denture

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar Singhal

    2017-01-01

    Full Text Available Successful rehabilitation of a patient should restore function, esthetic, and speech by prosthesis. Treatment modalities vary from patient to patient. Semi-precision attachments and implants offer several advantages over the traditional approach. The aim and objective of this report was to assess a case of a 55-year-old female patient who had lost all her teeth, except maxillary canines #13 and #23 and with severe bone loss in the mandible. Tooth-supported bar attachment was planned for maxilla, and a total of five dental implants were placed in the mandible using a flapless approach aided by radiographic gutta-percha surgical stents over panoramic two-dimensional imaging. Customized, radiographic stents help for the placement of implant in the view of paralleling and flapless surgery, completely. An immediate loading protocol is adopted as from day of the surgery to 6 weeks along with implant supported full arch fixed dentures after 4 months. The outcome of the treatment was impressive, and the patient gave a positive response with superb esthetics and functions.

  15. Investigation of superstructure damping identification for the HDR containment building

    International Nuclear Information System (INIS)

    Hsieh, B.J.; Kot, C.A.; Srinivasan, M.G.

    1985-01-01

    A method for the estimation of first mode structural damping, developed by other investigators, was applied to shaker test data of the HDR containment building. Due to inadequate precision in the experimental phase measurements no valid results could be obtained. Based on modal analysis it was also noted that for systems such as the HDR building, contributions of higher modes are not negligible as was assumed in the original approach. Therefore, the procedure for the determination of superstructure damping using experimental data was extended to include the effects of higher modes. The extended method does not lead to any higher order nonlinear equations than the first mode approximation and was found to be as simple to apply as the original approach

  16. Immediate restoration of single tapered implants with nonoccluding provisional crowns: a 5-year clinical prospective study.

    Science.gov (United States)

    Lang, Lisa A; Turkyilmaz, Ilser; Edgin, Wendell A; Verrett, Ronald; Garcia, Lily T

    2014-04-01

    Dental literature has limited number of publications regarding long-term outcome data of immediate restoration of single missing teeth with an implant-supported provisional crown. This 5-year study evaluated hard and soft tissue responses to the immediate placement of single implant-supported provisional crowns. Twenty patients received one dental implant restored immediately with a provisional acrylic resin screw-retained crown. Crestal bone loss was evaluated from standardized periapical radiographs collected at 3-month intervals for the first 21 months followed by a 5-year evaluation. Historical controls acquired from available dental literature were used for comparison. One implant failed within 2 months of surgical placement, presenting with pain and mobility. The remaining implants demonstrated no infection, pain, or radiolucencies. Nineteen implants were clinically immobile, osseointegrated, and asymptomatic at 21 months. At 5 years, one patient died, three patients were noncompliant, and 15 implants were evaluated as functional. Mean bone loss (MBL) at 1 year and 21 months was approximately 0.5 ± 0.5 mm and 0.70 ± 0.26 mm at 5 years. There was no statistically significant difference between MBLs at p provisionalization of single dental implants compares favorably with conventional loading protocols. Long-term data suggest that immediate provisionalization of single dental implants is a viable treatment option. © 2012 Wiley Periodicals, Inc.

  17. Intracorporeal Heat Distribution from Fully Implantable Energy Sources for Mechanical Circulatory Support: A Computational Proof-of-Concept Study

    Directory of Open Access Journals (Sweden)

    Jacopo Biasetti

    2017-10-01

    Full Text Available Mechanical circulatory support devices, such as total artificial hearts and left ventricular assist devices, rely on external energy sources for their continuous operation. Clinically approved power supplies rely on percutaneous cables connecting an external energy source to the implanted device with the associated risk of infections. One alternative, investigated in the 70s and 80s, employs a fully implanted nuclear power source. The heat generated by the nuclear decay can be converted into electricity to power circulatory support devices. Due to the low conversion efficiencies, substantial levels of waste heat are generated and must be dissipated to avoid tissue damage, heat stroke, and death. The present work computationally evaluates the ability of the blood flow in the descending aorta to remove the locally generated waste heat for subsequent full-body distribution and dissipation, with the specific aim of investigating methods for containment of local peak temperatures within physiologically acceptable limits. To this aim, coupled fluid–solid heat transfer computational models of the blood flow in the human aorta and different heat exchanger architectures are developed. Particle tracking is used to evaluate temperature histories of cells passing through the heat exchanger region. The use of the blood flow in the descending aorta as a heat sink proves to be a viable approach for the removal of waste heat loads. With the basic heat exchanger design, blood thermal boundary layer temperatures exceed 50°C, possibly damaging blood cells and proteins. Improved designs of the heat exchanger, with the addition of fins and heat guides, allow for drastically lower blood temperatures, possibly leading to a more biocompatible implant. The ability to maintain blood temperatures at biologically compatible levels will ultimately allow for the body-wise distribution, and subsequent dissipation, of heat loads with minimum effects on the human physiology.

  18. Intracorporeal Heat Distribution from Fully Implantable Energy Sources for Mechanical Circulatory Support: A Computational Proof-of-Concept Study.

    Science.gov (United States)

    Biasetti, Jacopo; Pustavoitau, Aliaksei; Spazzini, Pier Giorgio

    2017-01-01

    Mechanical circulatory support devices, such as total artificial hearts and left ventricular assist devices, rely on external energy sources for their continuous operation. Clinically approved power supplies rely on percutaneous cables connecting an external energy source to the implanted device with the associated risk of infections. One alternative, investigated in the 70s and 80s, employs a fully implanted nuclear power source. The heat generated by the nuclear decay can be converted into electricity to power circulatory support devices. Due to the low conversion efficiencies, substantial levels of waste heat are generated and must be dissipated to avoid tissue damage, heat stroke, and death. The present work computationally evaluates the ability of the blood flow in the descending aorta to remove the locally generated waste heat for subsequent full-body distribution and dissipation, with the specific aim of investigating methods for containment of local peak temperatures within physiologically acceptable limits. To this aim, coupled fluid-solid heat transfer computational models of the blood flow in the human aorta and different heat exchanger architectures are developed. Particle tracking is used to evaluate temperature histories of cells passing through the heat exchanger region. The use of the blood flow in the descending aorta as a heat sink proves to be a viable approach for the removal of waste heat loads. With the basic heat exchanger design, blood thermal boundary layer temperatures exceed 50°C, possibly damaging blood cells and proteins. Improved designs of the heat exchanger, with the addition of fins and heat guides, allow for drastically lower blood temperatures, possibly leading to a more biocompatible implant. The ability to maintain blood temperatures at biologically compatible levels will ultimately allow for the body-wise distribution, and subsequent dissipation, of heat loads with minimum effects on the human physiology.

  19. Novel superstructure of the rocksalt type and element distribution in germanium tin antimony tellurides

    Energy Technology Data Exchange (ETDEWEB)

    Rosenthal, Tobias [Department of Chemistry, Ludwig Maximilian University, Butenandtstraße 5-13, 81377 Munich (Germany); Welzmiller, Simon [Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststraße 20, 04275 Leipzig (Germany); Neudert, Lukas [Department of Chemistry, Ludwig Maximilian University, Butenandtstraße 5-13, 81377 Munich (Germany); Urban, Philipp [Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststraße 20, 04275 Leipzig (Germany); Fitch, Andy [European Synchrotron Radiation Facility, CS40220, 38043 Grenoble Cedex 9 (France); Oeckler, Oliver, E-mail: oliver.oeckler@gmx.de [Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststraße 20, 04275 Leipzig (Germany)

    2014-11-15

    A superstructure of the rocksalt-type observed in quenched CVT-grown single crystals of Ge{sub 3.25(7)}Sn{sub 1.10(3)}Sb{sub 1.10(3)}Te{sub 6} was elucidated by X-ray diffraction using fourfold twinned crystals (space group P3{sup ¯}m1, a=4.280(1) Å, c=20.966(3) Å). The structure is built up of distorted rocksalt-type building blocks typical for long-range ordered GST materials and substitution variants thereof. In contrast to those phases, an exclusive ABC-type cubic stacking sequence of the Te-atom layers is present. High-resolution electron microscopy reveals spheroidal domains with this structure (average diameter 25 nm) whose stacking direction is perpendicular to the 〈1 1 1〉 directions of the basic rocksalt-type structure. Additional slab-like domains with a lateral extension up to 1 µm occasionally result in a hierarchical structure motif. Due to the similar electron counts of the elements involved, resonant diffraction was used in order to elucidate the element distribution in rocksalt-type building blocks of the stable layered compound 39R-Ge{sub 3}SnSb{sub 2}Te{sub 7} (R3{sup ¯}m, a=4.24990(4) Å, c=73.4677(9) Å). Sb tends to occupy the atom site close to the van der Waals gaps while Ge concentrates in the center of the building blocks. - Graphical abstract: High-resolution transmission electron micrograph, SAED pattern and reciprocal lattice section of X-ray single crystal data of Ge{sub 3.25}Sn{sub 1.1}Sb{sub 1.1}Te{sub 6} with an 11P-type superstructure of the rocksalt type. - Highlights: • A novel superstructure of the rocksalt-type in the system Ge–Sn–Sb–Te is elucidated. • It combines the cubic stacking of the HT phase with building blocks of the RT phase. • It indicates the ordering mechanism during the phase transition of GST materials. • A hierarchical structure motif is promising with respect to the reduction of κ{sub L}. • Resonant diffraction reveals the element distribution in 39R-Ge{sub 3}SnSb{sub 2}Te{sub 7}.

  20. Last piece of ATLAS takes the plunge

    CERN Multimedia

    2008-01-01

    On Friday 29 February the second small wheel was lowered 100 metres underground into the ATLAS cavern in front of a captivated audience. Although called the "small wheels" they are small in name only - each wheel is 9.3 metres in diameter and weighs 100 tonnes including the massive shielding elements. This piece completes ATLAS’ muon spectrometer, which has the ability to accurately track particles to the width of a human hair. The first piece of ATLAS was installed in 2003 and, five years later, this small wheel is the final large piece of the detector to take the subterranean voyage to its final resting place.