The natural history of Becker expandable breast implants: a single-center 10-year experience.

Science.gov (United States)

Sindali, Katia; Davis, Marcus; Mughal, Maleeha; Orkar, Kusu S

2013-09-01

Use of Becker expandable breast implants in single-stage breast surgery is a well-established technique; however, replacement with fixed-volume implants is common. The authors sought to analyze the long-term natural history of these implants over a wide range of surgical indications. A retrospective review of 330 consecutive patients who underwent 384 Becker expander breast reconstructions over a 10-year period in a dedicated plastic surgery unit was undertaken. Implant indication, Becker type, volume and site, complications, expander lifespan, and explant reasons were assessed. Two hundred twenty-eight patients (267 implants) and 102 patients (117 implants) underwent implantation for congenital deformities and breast cancer reconstruction, respectively. One hundred eighty-seven (48 percent) were explanted at a median period of 13.0 months (range, 9.0 to 26.0 months), 149 (39 percent) for aesthetic reasons and 38 (10 percent) for complications. Complication rates were higher in breast cancer reconstruction compared with congenital patients (19.6 percent versus 7.9 percent; p = 0.002), driven by an increased rate of wound complications (13.7 percent versus 4.4 percent; p = 0.003). Cancer-related surgery and advancing age were the only predictors of complication risk. The overall Becker expander retention rate was 24.9 percent and 46.8 percent at 150 months in the cancer reconstruction and congenital groups, respectively. Forty-seven percent of Becker implants were retained long term after congenital corrective surgery; only 25 percent were retained after postmastectomy reconstruction. Poor aesthetics was driving the exchange for fixed-volume implants, indicating that after breast cancer reconstruction, Becker expanders were being used as part of a two-stage reconstructive strategy.

Early stages of oxidation of ion-implanted nickel at high temperature

International Nuclear Information System (INIS)

Peide, Z.; Grant, W.A.; Procter, R.P.M.

1981-01-01

The early stages of oxidation of nickel implanted with nickel, chromium, or lithium ions in oxygen at 1100 0 C have been studied using various electron-optical techniques. The unimplanted metal develops initially a fine-grained, convoluted scale having a ridged, cellular structure. Subsequently, the oxide grains increase in size significantly and oxidation becomes predominantly controlled by diffusion of Ni /sup 2+/ ions across a compact, columnar scale. Implantation of the surface with nickel ions has no significant effect on the initial oxidation behavior. However, after implantation with chromium or lithium ions, the development of the NiO scale is, in the early stages of oxidation, suppressed by formation of NiCr 2 O 4 or LiO 2 nodules, respectively. Subsequently, the implanted species are incorporated into the steady-state NiO scale where they dope the oxide and thus influence the diffusion rate of Ni /sup 2+/ ions through it. As would be predicted, the steady-state oxidation rate of chromium-implanted nickel is increased while that of lithium- implanted nickel is decreased compared with that of the unimplanted metal

Cochlear implantation for single-sided deafness and tinnitus suppression.

Science.gov (United States)

Holder, Jourdan T; O'Connell, Brendan; Hedley-Williams, Andrea; Wanna, George

To quantify the potential effectiveness of cochlear implantation for tinnitus suppression in patients with single-sided deafness using the Tinnitus Handicap Inventory. The study included 12 patients with unilateral tinnitus who were undergoing cochlear implantation for single-sided deafness. The Tinnitus Handicap Inventory was administered at the patient's cochlear implant candidacy evaluation appointment prior to implantation and every cochlear implant follow-up appointment, except activation, following implantation. Patient demographics and speech recognition scores were also retrospectively recorded using the electronic medical record. A significant reduction was found when comparing Tinnitus Handicap Inventory score preoperatively (61.2±27.5) to the Tinnitus Handicap Inventory score after three months of cochlear implant use (24.6±28.2, p=0.004) and the Tinnitus Handicap Inventory score beyond 6months of CI use (13.3±18.9, p=0.008). Further, 45% of patients reported total tinnitus suppression. Mean CNC word recognition score improved from 2.9% (SD 9.4) pre-operatively to 40.8% (SD 31.7) by 6months post-activation, which was significantly improved from pre-operative scores (p=0.008). The present data is in agreement with previously published studies that have shown an improvement in tinnitus following cochlear implantation for the large majority of patients with single-sided deafness. Copyright © 2017 Elsevier Inc. All rights reserved.

Randomized study on the effect of single-implant versus two-implant retained overdentures on implant loss and muscle activity: a 12-month follow-up report.

Science.gov (United States)

Alqutaibi, A Y; Kaddah, A F; Farouk, M

2017-06-01

The objective was to evaluate and compare single- and two-implant retained overdentures for the rehabilitation of the edentulous mandible. Fifty-six edentulous subjects were eligible for inclusion. Using a random sampling system, a single implant or two implants were placed in the mandible. After 3 months, locator attachments were connected to the implants and the denture delivered with the retentive components incorporated in the denture base. Implant failure and muscle activity were evaluated at the 3-, 6-, and 12-month follow-up examinations. The study sample comprised 56 patients (32 male, 24 female), with a mean age of 58.2 years. A total of 84 implants were placed (28 in the single-implant group and 56 in the two-implant group). All patients completed the 12 months of follow-up. No significant differences were found between subjects in the two groups with respect to implant failure. With regard to improvements in muscle activity, the two-implant group showed statistically significant but perhaps not clinically important differences. Single-implant mandibular overdentures may be suggested as an alternative treatment modality for the rehabilitation of edentulous patients who cannot afford the cost of a two-implant overdenture. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Efficacies of 125I seed implantation in advanced stage central lung cancer via fibrobronchoscope

International Nuclear Information System (INIS)

Liu Jianguo; An Liqing; Cheng Jinguang; Zhang Yufen; Guo Xiaokui

2009-01-01

Objective: To explore the temporal curative effect of 125 I seed implantation in advanced stage central type lung cancer. Methods: 125 I seed was implanted in 56 patients confirmed advanced stage central type lung cancer via fibrobronchoscope and all cases were fellow up in certain duration to explore their efficacies and the adverse reaction. Results: Total efficient rate was 76.78% in 56 patients. Lung reexpanded rate was 90.90%. Conclusion: The therapy of 125 I seed implantation in advanced stage central type lung cancer is safe and available. (authors)

Single ion implantation for single donor devices using Geiger mode detectors

International Nuclear Information System (INIS)

Bielejec, E; Seamons, J A; Carroll, M S

2010-01-01

Electronic devices that are designed to use the properties of single atoms such as donors or defects have become a reality with recent demonstrations of donor spectroscopy, single photon emission sources, and magnetic imaging using defect centers in diamond. Ion implantation, an industry standard for atom placement in materials, requires augmentation for single ion capability including a method for detecting a single ion arrival. Integrating single ion detection techniques with the single donor device construction region allows single ion arrival to be assured. Improving detector sensitivity is linked to improving control over the straggle of the ion as well as providing more flexibility in lay-out integration with the active region of the single donor device construction zone by allowing ion sensing at potentially greater distances. Using a remotely located passively gated single ion Geiger mode avalanche diode (SIGMA) detector we have demonstrated 100% detection efficiency at a distance of >75 μm from the center of the collecting junction. This detection efficiency is achieved with sensitivity to ∼600 or fewer electron-hole pairs produced by the implanted ion. Ion detectors with this sensitivity and integrated with a thin dielectric, for example a 5 nm gate oxide, using low energy Sb implantation would have an end of range straggle of -1 and 10 -4 for operation temperatures of ∼300 K and ∼77 K, respectively. Low temperature operation and reduced false, 'dark', counts are critical to achieving high confidence in single ion arrival. For the device performance in this work, the confidence is calculated as a probability of >98% for counting one and only one ion for a false count probability of 10 -4 at an average ion number per gated window of 0.015.

Two-stage implant placement technique for the management of irradiated jaws: An animal study.

Science.gov (United States)

Aboushelib, Moustafa N; Arnaout, Mohamed A; Elsafi, Mohamed H; Kassem, Youssef M

2017-10-01

Radiotherapy results in diminished bone remodeling capacity and an elevated risk of osteoradionecrosis, which can negatively influence the survival rate of dental implants. Patients receiving radiotherapy are advised not to receive dental implants during or soon after completing their radiotherapy. The purpose of this animal study was to investigate a 2-stage implant placement technique designed to diminish applied trauma on irradiated bone. Two groups of white New Zealand rabbits received radiotherapy in ascending doses (2, 4, 8 Gy), while a nonirradiated group served as control. Three weeks after completion of the last radiotherapy session, one of the irradiated groups and the control group received titanium dental implants bilaterally in the femur head. For the second irradiated group, an osteotomy was performed, and the surgical wound was left to heal for 2 weeks before implant placement. All animals were sacrificed 4 weeks after implant placement, and histomorphometric analysis was used to study bone-implant contact (n=14, α=.05). Statistical analysis revealed significantly higher (F=159, P<.001) bone-implant contact in the 2-stage (40.2 ±1.9) implant placement technique than in the immediately placed implants (21.2 ±2.3) in irradiated bone. Both of the groups had a significantly lower bone-to-implant contact ratio than the non-irradiated control (64.2 ±3.8). Within the limitations of this animal study, the 2-stage implant placement technique could be used to reduce trauma in irradiated bone and to improve wound healing around dental implants. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Ion implantation induced blistering of rutile single crystals

Energy Technology Data Exchange (ETDEWEB)

Xiang, Bing-Xi [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Jiao, Yang [College of Physics and Electronics, Shandong Normal University, Jinan, Shandong 250100 (China); Guan, Jing [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Wang, Lei [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (China)

2015-07-01

The rutile single crystals were implanted by 200 keV He{sup +} ions with a series fluence and annealed at different temperatures to investigate the blistering behavior. The Rutherford backscattering spectrometry, optical microscope and X-ray diffraction were employed to characterize the implantation induced lattice damage and blistering. It was found that the blistering on rutile surface region can be realized by He{sup +} ion implantation with appropriate fluence and the following thermal annealing.

Temporary Piggyback Intraocular Lens Implantation Versus Single Intraocular Lens Implantation in Congenital Cataracts: Long-Term Clinical Outcomes.

Science.gov (United States)

Hwang, Sungsoon; Lim, Dong Hui; Lee, Soomin; Choi, Daye Diana; Chung, Eui-Sang; Chung, Tae-Young

2018-04-01

To report the long-term results of temporary piggyback IOL implantation in congenital cataract and to compare the clinical outcomes of temporary piggyback IOL with those of single IOL implantation. This is a retrospective, comparative, interventional study. The medical records of all consecutive patients who underwent cataract extraction and single or temporary piggyback IOL implantation within the first 3 years of life from 1999 to 2013 at Samsung Medical Center were reviewed. Twenty-eight eyes from 18 patients underwent single IOL implantation (monopseudophakia group), and 32 eyes of 20 patients underwent temporary piggyback IOL implantation in congenital cataract surgery (polypseudophakia group). The mean age at initial cataract surgery was 15.8 months in the monopseudophakia group and 11.1 months in the polypseudophakia group (P = 0.144). The average follow-up duration was 133 months in the monopseudophakia group and 120 months in the polypseudophakia group (P = 0.391). The best-corrected visual acuity at the last visit was 0.36 logMAR in the monopseudophakia group and 0.55 logMAR in the polypseudophakia group (P = 0.044). Four (14%) and 14 (44%) reoperations for complications within the anterior segment were performed in the monopseudophakia group and polypseudophakia group, respectively (P = 0.042). Four cases (14.3%) in the monopseudophakia group and 13 cases (40.6%) in the polypseudophakia group had a glaucoma-related adverse event (P = 0.086). Compared with primary single IOL implantation in congenital cataract, temporary piggyback IOL implantation produced worse visual acuity, higher reoperation rate, and higher risk of secondary glaucoma. Temporary piggyback IOL implantation does not have benefit in congenital cataract.

Single-staged resections and 3D reconstructions of the nasion, glabella, medial orbital wall, and frontal sinus and bone: Long-term outcome and review of the literature.

Science.gov (United States)

Ciporen, Jeremy; Lucke-Wold, Brandon P; Mendez, Gustavo; Chen, Anton; Banerjee, Amit; Akins, Paul T; Balough, Ben J

2016-01-01

Aesthetic facial appearance following neurosurgical ablation of frontal fossa tumors is a primary concern for patients and neurosurgeons alike. Craniofacial reconstruction procedures have drastically evolved since the development of three-dimensional computed tomography imaging and computer-assisted programming. Traditionally, two-stage approaches for resection and reconstruction were used; however, these two-stage approaches have many complications including cerebrospinal fluid leaks, necrosis, and pneumocephalus. We present two successful cases of single-stage osteoma resection and craniofacial reconstruction in a 26-year-old female and 65-year-old male. The biopolymer implants were preselected and contoured based on imaging prior to surgery. The ideal selection of appropriate flaps for reconstruction was imperative. The flaps were well vascularized and included a pedicle for easy translocation. Using a titanium mesh biopolymer implant for reconstruction in conjunction with a forehead flap proved advantageous, and the benefits of single-stage approaches were apparent. The patients recovered quickly after the surgery with complete resection of the osteoma and good aesthetic appearance. The flap adhered to the biopolymer implant, and the cosmetic appearance years after surgery remained decent. The gap between the bone and implant was less than 2 mm. The patients are highly satisfied with the symmetrical appearance of the reconstruction. Advances in technology are allowing neurosurgeons unprecedented opportunities to design complex yet feasible single-stage craniofacial reconstructions that improve a patient's quality of life by enhancing facial contours, aesthetics, and symmetry.

Economic evaluation of single-tooth replacement: dental implant versus fixed partial denture.

Science.gov (United States)

Kim, Younhee; Park, Joo-Yeon; Park, Sun-Young; Oh, Sung-Hee; Jung, YeaJi; Kim, Ji-Min; Yoo, Soo-Yeon; Kim, Seong-Kyun

2014-01-01

This study assessed the cost-effectiveness from a societal perspective of a dental implant compared with a three-unit tooth-supported fixed partial denture (FPD) for the replacement of a single tooth in 2010. A decision tree was developed to estimate cost-effectiveness over a 10-year period. The survival rates of single-tooth implants and FPDs were extracted from a meta-analysis of single-arm studies. Medical costs included initial treatment costs, maintenance costs, and costs to treat complications. Patient surveys were used to obtain the costs of the initial single-tooth implant or FPD. Maintenance costs and costs to treat complications were based on surveys of seven clinical experts at dental clinics or hospitals. Transportation costs were calculated based on the number of visits for implant or FPD treatment. Patient time costs were estimated using the number of visits and time required, hourly wage, and employment rate. Future costs were discounted by 5% to convert to present values. The results of a 10-year period model showed that a single dental implant cost US $261 (clinic) to $342 (hospital) more than an FPD and had an average survival rate that was 10.4% higher. The incremental cost-effectiveness ratio was $2,514 in a clinic and $3,290 in a hospital for a prosthesis in situ for 10 years. The sensitivity analysis showed that initial treatment costs and survival rate influenced the cost-effectiveness. If the cost of an implant were reduced to 80% of the current cost, the implant would become the dominant intervention. Although the level of evidence for effectiveness is low, and some aspects of single-tooth implants or FPDs, such as satisfaction, were not considered, this study will help patients requiring single-tooth replacement to choose the best treatment option.

Improving neuromodulation technique for refractory voiding dysfunctions: two-stage implant.

Science.gov (United States)

Janknegt, R A; Weil, E H; Eerdmans, P H

1997-03-01

Neuromodulation is a new technique that uses electrical stimulation of the sacral nerves for patients with refractory urinary urge/frequency or urge-incontinence, and some forms of urinary retention. The limiting factor for receiving an implant is often a failure of the percutaneous nerve evaluation (PNE) test. Present publications mention only about a 50% success score for PNE of all patients, although the micturition diaries and urodynamic parameters are similar. We wanted to investigate whether PNE results improved by using a permanent electrode as a PNE test. This would show that improvement of the PNE technique is feasible. In 10 patients where the original PNE had failed to improve the micturition diary parameters more than 50%, a permanent electrode was implanted by operation. It was connected to an external stimulator. In those cases where the patients improved according to their micturition diary by more than 50% during a period of 4 days, the external stimulator was replaced by a permanent subcutaneous neurostimulator. Eight of the 10 patients had a good to very good result (60% to 90% improvement) during the testing period and received their implant 5 to 14 days after the first stage. The good results of the two-stage implant technique we used indicate that the development of better PNE electrodes may lead to an improvement of the testing technique and better selection between nonresponders and technical failures.

Contemporary rates and outcomes of single- vs. dual-coil implantable cardioverter defibrillator lead implantation: data from the Israeli ICD Registry.

Science.gov (United States)

Leshem, Eran; Suleiman, Mahmoud; Laish-Farkash, Avishag; Konstantino, Yuval; Glikson, Michael; Barsheshet, Alon; Goldenberg, Ilan; Michowitz, Yoav

2017-09-01

Dual-coil leads were traditionally considered standard of care due to lower defibrillation thresholds (DFT). Higher complication rates during extraction with parallel progression in implantable cardioverter defibrillator (ICD) technology raised questions on dual coil necessity. Prior substudies found no significant outcome difference between dual and single coils, although using higher rates of DFT testing then currently practiced. We evaluated the temporal trends in implantation rates of single- vs. dual-coil leads and determined the associated adverse clinical outcomes, using a contemporary nation-wide ICD registry. Between July 2010 and March 2015, 6343 consecutive ICD (n = 3998) or CRT-D (n = 2345) implantation patients were prospectively enrolled in the Israeli ICD Registry. A follow-up of at least 1 year of 2285 patients was available for outcome analysis. The primary endpoint was all-cause mortality. Single-coil leads were implanted in 32% of our cohort, 36% among ICD recipients, and 26% among CRT-D recipients. Secondary prevention indication was associated with an increased rate of dual-coil implantation. A significant decline in dual-coil leads with reciprocal incline of single coils was observed, despite low rates of DFT testing (11.6%) during implantation, which also declined from 31 to 2%. In the multivariate Cox model analysis, dual- vs. single-coil lead implantation was not associated with an increased risk of mortality [hazard ratio (HR) = 1.23; P= 0.33], heart failure hospitalization (HR = 1.34; P=0.13), appropriate (HR = 1.25; P= 0.33), or inappropriate ICD therapy (HR = 2.07; P= 0.12). Real-life rates of single-coil lead implantation are rising while adding no additional risk. These results of single-coil safety are reassuring and obtained, despite low and contemporary rates of DFT testing. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Evaluation of mandibular posterior single implants with two different surfaces: a 5-year comparative study.

Science.gov (United States)

Jung, Ui-Won; Choi, Jung-Yoo; Kim, Chang-Sung; Cho, Kyoo-Sung; Chai, Jung-Kiu; Kim, Chong-Kwan; Choi, Seong-Ho

2008-10-01

Anatomic and biomechanical limitations can jeopardize successful single implantation in the mandibular posterior area. To overcome the limitations, the design and the surface of the fixtures were modified. This study evaluated the cumulative survival rate (CSR) of mandibular molars replaced with a sand-blasted, large-grit, acid-etched (SLA) single implant or an anodized (ANO) single implant and examined associated factors, such as the surface treatment, position, and length and diameter of the implants. One hundred ninety-three single implants restored with an SLA implant and 112 single implants restored with an ANO implant in the mandibular molar area were selected from subjects who had visited the Department of Periodontology, Dental Hospital of Yonsei University, from March 2001 through June 2006. In the SLA group, 123 and 70 implants were placed in the first and second molar area, respectively. In the ANO group, 55 and 57 implants were placed in the first and second molar area, respectively. The 1- to 6-year CSR of the SLA and ANO groups was calculated using the life-table analysis. In addition, associated factors, such as the surface treatment, position, and length and diameter of the implants, were compared and analyzed using the chi(2) test (P CSR of 98.96%; four of 112 ANO implants failed, giving a CSR of 96.43%. There were no significant differences with regard to the surface treatment, position, and length and diameter of the implants. Despite the anatomic and biomechanical limitation in the mandibular posterior area, mandibular posterior single implants showed a high CSR during the observation period. Mandibular posterior single implants can be an effective and reliable treatment modality that is not affected by the surface treatment, position, or length and diameter of the implant.

Single-tooth replacement by osseointegrated Astra Tech dental implants: a 2-year report

DEFF Research Database (Denmark)

Karlsson, U; Gotfredsen, K; Olsson, C

1998-01-01

This study presents the outcome of single-tooth restorations supported by Astra Tech single-tooth implants followed for 2 years. Forty-seven implants were placed in the same number of patients. Forty-three patients attended the second recall visit, and none of the evaluated implants have been...

Immediate loading with single-piece implant following extraction

Directory of Open Access Journals (Sweden)

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.

Efficacy and safety of a diode laser in second-stage implant surgery: a comparative study.

Science.gov (United States)

El-Kholey, K E

2014-05-01

For more than a decade, peri-implant tissues have been treated with soft tissue lasers to create a bloodless flap for implant placement and to uncover implants with minimal bleeding, trauma, and anaesthesia. This study was designed to assess if dental implant uncovering is possible with a diode laser without anaesthesia, and to compare its performance with traditional cold scalpel surgery. Thirty patients with a total of 45 completely osseointegrated implants participated in this study. Patients were divided into two groups. For the study group, second-stage implant surgery was done with a 970nm diode laser. For the control group, the implants were exposed with a surgical blade. Certain parameters were used for evaluation of the two techniques. The use of the diode laser obviated the need for local anaesthesia; there was a significant difference between the two groups regarding the need for anaesthesia (Pdiode laser can be used effectively for second-stage implant surgery, providing both the dentist and the patient with additional advantages over the conventional methods used for implant exposure. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Esthetic evaluation of single-tooth implants in the anterior mandible.

Science.gov (United States)

Hof, Markus; Tepper, Gabor; Koller, Barbara; Krainhöfner, Martin; Watzek, Georg; Pommer, Bernhard

2014-09-01

Single-tooth replacement of anterior mandibular teeth is frequently complicated by insufficient bucco-lingual bone width and limited mesio-distal space available for implant placement. The aim of the present study was to assess implant esthetics in the partially edentulous anterior mandible. Esthetic evaluation of 43 anterior mandibular single-tooth implants in 15 women and 28 men was performed using esthetic indices (PES = Pink Esthetic Score, PI = Papilla Index, SES = Subjective Esthetic Score) as well as subjective patients' Visual Analogue Scale (VAS) ratings. Clinical and radiological parameters (implant and crown dimensions, pocket depth, bleeding on probing, plaque, keratinized mucosa, marginal bone level, and distance to adjacent teeth) were tested for influence. Implant esthetics were judged satisfactory (PES ≤10) in 42% of implants compared with a patient satisfaction rate of 87%. Correlation between objective indices (PES/PI: rs  = 0.62, PES/SES: rs  = -0.73, PI/SES: rs  = -0.48) was highly significant (P ≤ 0.001); however, no association to subjective patients' ratings could be observed. Type of prosthetic restoration (single crown vs. tulip-shaped double crowns), mesio-distal crown width as well as anatomic crown length significantly affected esthetic scores. Patients' judgment, by contrast, could not be associated to any prognostic factor. Subjective patient satisfaction with implant esthetics in the partially edentulous anterior mandible is high, however, remains hard to predict or objectively quantify. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Six-year clinical outcome of single implant-retained mandibular overdentures--a pilot study.

Science.gov (United States)

Passia, Nicole; Wolfart, Stefan; Kern, Matthias

2015-10-01

The aim of this prospective pilot study was to evaluate the prosthodontic maintenance as well as the implant outcome of single implant-retained mandibular overdentures over an observation period of 6 years. Eleven edentulous patients received one single implant in the midline of the mandible. Denture bases were temporarily relined and 2 months later provided with a ball attachment for implant retention. Implant related parameters and prosthodontic maintenance interventions were assessed 4 weeks after implant loading and then once a year. Over a mean observation period of 75.9 months, no implant was lost. The most frequent prosthetic maintenance intervention was activation of the matrix due to loss of retention, followed by exchange of the female part. Eight denture bases had to be repaired after a fracture in the midline area. Within the limitations of this preliminary clinical study, the concept of a single midline implant to retain a mandibular complete denture was a successful treatment option for elderly edentulous patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Two-Stage Latissimus Dorsi Flap with Implant for Unilateral Breast Reconstruction: Getting the Size Right

Directory of Open Access Journals (Sweden)

Jiajun Feng

2016-03-01

Full Text Available BackgroundThe aim of unilateral breast reconstruction after mastectomy is to craft a natural-looking breast with symmetry. The latissimus dorsi (LD flap with implant is an established technique for this purpose. However, it is challenging to obtain adequate volume and satisfactory aesthetic results using a one-stage operation when considering factors such as muscle atrophy, wound dehiscence and excessive scarring. The two-stage reconstruction addresses these difficulties by using a tissue expander to gradually enlarge the skin pocket which eventually holds an appropriately sized implant.MethodsWe analyzed nine patients who underwent unilateral two-stage LD reconstruction. In the first stage, an expander was placed along with the LD flap to reconstruct the mastectomy defect, followed by gradual tissue expansion to achieve overexpansion of the skin pocket. The final implant volume was determined by measuring the residual expander volume after aspirating the excess saline. Finally, the expander was replaced with the chosen implant.ResultsThe average volume of tissue expansion was 460 mL. The resultant expansion allowed an implant ranging in volume from 255 to 420 mL to be placed alongside the LD muscle. Seven patients scored less than six on the relative breast retraction assessment formula for breast symmetry, indicating excellent breast symmetry. The remaining two patients scored between six and eight, indicating good symmetry.ConclusionsThis approach allows the size of the eventual implant to be estimated after the skin pocket has healed completely and the LD muscle has undergone natural atrophy. Optimal reconstruction results were achieved using this approach.

Rationale for one stage exchange of infected hip replacement using uncemented implants and antibiotic impregnated bone graft.

Science.gov (United States)

Winkler, Heinz

2009-09-04

Infection of a total hip replacement (THR) is considered a devastating complication, necessitating its complete removal and thorough debridement of the site. It is undoubted that one stage exchange, if successful, would provide the best benefit both for the patient and the society. Still the fear of re-infection dominates the surgeons decisions and in the majority of cases directs them to multiple stage protocols. However, there is no scientifically based argument for that practice. Successful eradication of infection with two stage procedures is reported to average 80% to 98%. On the other hand a literature review of Jackson and Schmalzried (CORR 2000) summarizing the results of 1,299 infected hip replacements treated with direct exchange (almost exclusively using antibiotic loaded cement), reports of 1,077 (83%) having been successful. The comparable results suggest, that the major factor for a successful outcome with traditional approaches may be found in the quality of surgical debridement and dead space management. Failures in all protocols seem to be caused by small fragments of bacterial colonies remaining after debridement, whereas neither systemic antibiotics nor antibiotic loaded bone cement (PMMA) have been able to improve the situation significantly. Reasons for failure may be found in the limited sensitivity of traditional bacterial culturing and reduced antibiotic susceptibility of involved pathogens, especially considering biofilm formation. Whenever a new prosthesis is implanted into a previously infected site the surgeon must be aware of increased risk of failure, both in single or two stage revisions. Eventual removal therefore should be easy with low risk of additional damage to the bony substance. On the other hand it should also have potential of a good long term result in case of success. Cemented revisions generally show inferior long term results compared to uncemented techniques; the addition of antibiotics to cement reduces its

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

Development of a keV single-ion-implanter for nanofabrication

International Nuclear Information System (INIS)

Yang, C.; Jamieson, D.N.; Hopf, T.; Tamanyan, G.; Spizziri, P.; Pakes, C.; Andresen, S.E.; Hudson, F.; Gauja, E.; Dzurak, A.; Clark, R.G.

2005-01-01

Traditional methods of doping semiconductors have a difficulty meeting the demand for high precision doping due to large statistical fluctuations in the numbers of dopant atoms introduced in the ever shrinking volume in micro- and nano-electronics devices, especially when the fabrication process approaches the nanometre scale. The statistical fluctuations in doping semiconductors for the fabrication of devices with a very small feature size may lead to inconsistent and unreliable performance. This paper describes the adaptation of a commercial ion implanter into a single-ion-implantation system for the accurate delivery of dopants into a nanometre or micrometre area in a silicon substrate. All the implanted ions can be accurately counted with near 100% certainty through online detection using the silicon substrate itself as an ion detector. A variety of ion species including B + , N + , P + at the energy range of 10-15 keV can be delivered in the single ion implantation system. (author). 6 refs., 6 figs

Single-Ion Implantation for the Development of Si-Based MOSFET Devices with Quantum Functionalities

Directory of Open Access Journals (Sweden)

Jeffrey C. McCallum

2012-01-01

Full Text Available Interest in single-ion implantation is driven in part by research into development of solid-state devices that exhibit quantum behaviour in their electronic or optical characteristics. Here, we provide an overview of international research work on single ion implantation and single ion detection for development of electronic devices for quantum computing. The scope of international research into single ion implantation is presented in the context of our own research in the Centre for Quantum Computation and Communication Technology in Australia. Various single ion detection schemes are presented, and limitations on dopant placement accuracy due to ion straggling are discussed together with pathways for scale-up to multiple quantum devices on the one chip. Possible future directions for ion implantation in quantum computing and communications are also discussed.

Assessment of implant stability during various stages of healing placed immediately following extraction in an overdenture situation

Directory of Open Access Journals (Sweden)

Ashwin Thomas Koshy

2017-01-01

Full Text Available To assess the implant stability during different stages of healing in an immediate loaded implant soon after extraction. A 73-year-old female came with a chief complaint of bad smell and irritation in her lower front gum region. On examination, she was found to be completely edentulous in the maxillary arch and partially edentulous in the mandibular arch with only the canines present bilaterally. The posterior mandibular ridge was severely resorbed and hence could not be treated with a conventional mandibular complete denture. Considering the age of the patient and the preference of only a single surgical visit, we decided to plan for a conventional maxillary denture against an implant supported mandibular overdenture with two implants placed immediately after extraction of canines. The stability of these implants was assessed during the early phases of healing with the help of a resonance frequency analysis method (RFA using Osstell ISQ™. During the healing phase, implant stability quotient (ISQ values decrease by 4–5 values after installation with the lowest values at the 1st week postplacement. Following this, the ISQ values increased steadily for all implants up to 16 weeks. No significant differences were noted over time. At placement, the mean ISQ values at 33 and 43 regions were 74 and 75.2, respectively. The mean lowest ISQ values recorded at the 1st week were 58.8 and 65.4, respectively. At 16 weeks, the mean ISQ values were 70.5 and 67.9, respectively. The survival of such immediately placed implants, which are later used as overdenture supported implants, are highly predictable when the surgical and prosthetic part is done meticulously. However, there needs future studies oriented to understand better the healing pattern of immediately placed implants in extraction sockets, which would guide the clinician with the optimal loading time.

When is an implant ready for a tooth?

Science.gov (United States)

Tupac, Robert G

2003-12-01

The capability of placing an osseointegrated implant at the time of tooth extraction and immediately placing a restoration on the implant depends upon a number of factors. This paper describes the traditional Brånemark protocol, the evolution of single-stage surgery, the guidelines for immediate placement, the measurement of implant stability, and the considerations critical to immediately loading.

CMOS single-stage input-powered bridge rectifier with boost switch and duty cycle control

Science.gov (United States)

Radzuan, Roskhatijah; Mohd Salleh, Mohd Khairul; Hamzah, Mustafar Kamal; Ab Wahab, Norfishah

2017-06-01

This paper presents a single-stage input-powered bridge rectifier with boost switch for wireless-powered devices such as biomedical implants and wireless sensor nodes. Realised using CMOS process technology, it employs a duty cycle switch control to achieve high output voltage using boost technique, leading to a high output power conversion. It has only six external connections with the boost inductance. The input frequency of the bridge rectifier is set at 50 Hz, while the switching frequency is 100 kHz. The proposed circuit is fabricated on a single 0.18-micron CMOS die with a space area of 0.024 mm2. The simulated and measured results show good agreement.

Single dental implant retained mandibular complete dentures – influence of the loading protocol: study protocol for a randomized controlled trial

Science.gov (United States)

2014-01-01

Background Over the years, there has been a strong consensus in dentistry that at least two implants are required to retain a complete mandibular denture. It has been shown in several clinical trials that one single median implant can retain a mandibular overdenture sufficiently well for up to 5 years without implant failures, when delayed loading was used. However, other trials have reported conflicting results with in part considerable failure rates when immediate loading was applied. Therefore it is the purpose of the current randomized clinical trial to test the hypothesis that immediate loading of a single mandibular midline implant with an overdenture will result in a comparable clinical outcome as using the standard protocol of delayed loading. Methods/design This prospective nine-center randomized controlled clinical trial is still ongoing. The final patient will complete the trial in 2016. In total, 180 edentulous patients between 60 and 89 years with sufficient complete dentures will receive one median implant in the edentulous mandible, which will retain the existing complete denture using a ball attachment. Loading of the median implant is either immediately after implant placement (experimental group) or delayed by 3 months of submerged healing at second-stage surgery (control group). Follow-up of patients will be performed for 24 months after implant loading. The primary outcome measure is non-inferiority of implant success rate of the experimental group compared to the control group. The secondary outcome measures encompass clinical, technical and subjective variables. The study was funded by the Deutsche Forschungsgemeinschaft (German research foundation, KE 477/8-1). Discussion This multi-center clinical trial will give information on the ability of a single median implant to retain a complete mandibular denture when immediately loaded. If viable, this treatment option will strongly improve everyday dental practice. Trial registration The trial

Stress analysis at bone-implant interface of single- and two-implant-retained mandibular overdenture using three-dimensional finite element analysis

Directory of Open Access Journals (Sweden)

Krishnakumar Lahoti

2016-01-01

Conclusion: Within the limitations of the study, it had been seen that stresses produced were the highest on HB and SB in single implant-retained mandibular overdenture while stresses produced across the denture as well as implant were the highest in two-implant-retained mandibular overdenture.

Patient satisfaction with single-tooth implant therapy in the esthetic zone

NARCIS (Netherlands)

den Hartog, Laurens; Meijer, Henny J. A.; Santing, Hendrik J.; Vissink, Arjan; Raghoebar, Gerry M.

2014-01-01

This prospective study assessed patient satisfaction before and after single-tooth implant therapy in the esthetic zone. Before implant therapy, patients wore an acrylic resin tissue-supported removable partial denture (RPD). A total of 153 patients were included. Self-administered questionnaires

Design considerations for single-stage and two-stage pneumatic pellet injectors

International Nuclear Information System (INIS)

Gouge, M.J.; Combs, S.K.; Fisher, P.W.; Milora, S.L.

1988-09-01

Performance of single-stage pneumatic pellet injectors is compared with several models for one-dimensional, compressible fluid flow. Agreement is quite good for models that reflect actual breech chamber geometry and incorporate nonideal effects such as gas friction. Several methods of improving the performance of single-stage pneumatic pellet injectors in the near term are outlined. The design and performance of two-stage pneumatic pellet injectors are discussed, and initial data from the two-stage pneumatic pellet injector test facility at Oak Ridge National Laboratory are presented. Finally, a concept for a repeating two-stage pneumatic pellet injector is described. 27 refs., 8 figs., 3 tabs

Study of shallow junction formation by boron-containing cluster ion implantation of silicon and two-stage annealing

Science.gov (United States)

Lu, Xin-Ming

Shallow junction formation made by low energy ion implantation and rapid thermal annealing is facing a major challenge for ULSI (ultra large scale integration) as the line width decreases down to the sub micrometer region. The issues include low beam current, the channeling effect in low energy ion implantation and TED (transient enhanced diffusion) during annealing after ion implantation. In this work, boron containing small cluster ions, such as GeB, SiB and SiB2, was generated by using the SNICS (source of negative ion by cesium sputtering) ion source to implant into Si substrates to form shallow junctions. The use of boron containing cluster ions effectively reduces the boron energy while keeping the energy of the cluster ion beam at a high level. At the same time, it reduces the channeling effect due to amorphization by co-implanted heavy atoms like Ge and Si. Cluster ions have been used to produce 0.65--2keV boron for low energy ion implantation. Two stage annealing, which is a combination of low temperature (550°C) preannealing and high temperature annealing (1000°C), was carried out to anneal the Si sample implanted by GeB, SiBn clusters. The key concept of two-step annealing, that is, the separation of crystal regrowth, point defects removal with dopant activation from dopant diffusion, is discussed in detail. The advantages of the two stage annealing include better lattice structure, better dopant activation and retarded boron diffusion. The junction depth of the two stage annealed GeB sample was only half that of the one-step annealed sample, indicating that TED was suppressed by two stage annealing. Junction depths as small as 30 nm have been achieved by two stage annealing of sample implanted with 5 x 10-4/cm2 of 5 keV GeB at 1000°C for 1 second. The samples were evaluated by SIMS (secondary ion mass spectrometry) profiling, TEM (transmission electron microscopy) and RBS (Rutherford Backscattering Spectrometry)/channeling. Cluster ion implantation

A glass fiber-reinforced composite - bioactive glass cranioplasty implant: A case study of an early development stage implant removed due to a late infection.

Science.gov (United States)

Posti, Jussi P; Piitulainen, Jaakko M; Hupa, Leena; Fagerlund, Susanne; Frantzén, Janek; Aitasalo, Kalle M J; Vuorinen, Ville; Serlo, Willy; Syrjänen, Stina; Vallittu, Pekka K

2015-03-01

This case study describes the properties of an early development stage bioactive glass containing fiber-reinforced composite calvarial implant with histology that has been in function for two years and three months. The patient is a 33-year old woman with a history of substance abuse, who sustained a severe traumatic brain injury later unsuccessfully treated with an autologous bone flap and a custom-made porous polyethylene implant. She was thereafter treated with developmental stage glass fiber-reinforced composite - bioactive glass implant. After two years and three months, the implant was removed due to an implant site infection. The implant was analyzed histologically, mechanically, and in terms of chemistry and dissolution of bioactive glass. Mechanical integrity of the load bearing fiber-reinforced composite part of the implant was not affected by the in vivo period. Bioactive glass particles demonstrated surface layers of hydroxyapatite like mineral and dissolution, and related increase of pH was considerably less after two and three months period than that for fresh bioactive glass. There was a difference in the histology of the tissues inside the implant areas near to the margin of the implant that absorbed blood during implant installation surgery, showed fibrous tissue with blood vessels, osteoblasts, collagenous fibers with osteoid formation, and tiny clusters of more mature hard tissue. In the center of the implant, where there was less absorbed blood, only fibrous tissue was observed. This finding is in line with the combined positron emission tomography - computed tomography examination with (18F)-fluoride marker, which demonstrated activity of the mineralizing bone by osteoblasts especially at the area near to the margin of the implant 10 months after implantation. Based on these promising reactions found in the bioactive glass containing fiber-reinforced composite implant that has been implanted for two years and three months, calvarial

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....

One-stage exchange with antibacterial hydrogel coated implants provides similar results to two-stage revision, without the coating, for the treatment of peri-prosthetic infection.

Science.gov (United States)

Capuano, Nicola; Logoluso, Nicola; Gallazzi, Enrico; Drago, Lorenzo; Romanò, Carlo Luca

2018-03-16

Aim of this study was to verify the hypothesis that a one-stage exchange procedure, performed with an antibiotic-loaded, fast-resorbable hydrogel coating, provides similar infection recurrence rate than a two-stage procedure without the coating, in patients affected by peri-prosthetic joint infection (PJI). In this two-center case-control, study, 22 patients, treated with a one-stage procedure, using implants coated with an antibiotic-loaded hydrogel [defensive antibacterial coating (DAC)], were compared with 22 retrospective matched controls, treated with a two-stage revision procedure, without the coating. At a mean follow-up of 29.3 ± 5.0 months, two patients (9.1%) in the DAC group showed an infection recurrence, compared to three patients (13.6%) in the two-stage group. Clinical scores were similar between groups, while average hospital stay and antibiotic treatment duration were significantly reduced after one-stage, compared to two-stage (18.9 ± 2.9 versus 35.8 ± 3.4 and 23.5 ± 3.3 versus 53.7 ± 5.6 days, respectively). Although in a relatively limited series of patients, our data shows similar infection recurrence rate after one-stage exchange with DAC-coated implants, compared to two-stage revision without coating, with reduced overall hospitalization time and antibiotic treatment duration. These findings warrant further studies in the possible applications of antibacterial coating technologies to treat implant-related infections. III.

Plasma immersion ion implantation: duplex layers from a single process

International Nuclear Information System (INIS)

Hutchings, R.; Collins, G.A.; Tendys, J.

1992-01-01

Plasma immersion ion implantation (PI 3 ) is an alternative non-line-of-sight technique for implanting ions directly from a plasma which surrounds the component to be treated. In contrast to plasma source ion implantation, the PI 3 system uses an inductively coupled r.f. plasma. It is shown that nitrogen can be retained during implantation at elevated temperatures, even for unalloyed steels. This allows controlled diffusion of nitrogen to greater depths, thereby improving the load bearing capacity of the implanted layer. Components can be heated directly, using the energy deposited by the incident ions during the pulsed implantation. The necessary temperature control can be accomplished simply by regulating the frequency and length of the high voltage pulses applied to the component. Chemical depth profiles and microstructural data obtained from H13 tool steel are used to show that PI 3 can, in a single process, effectively produce a duplex subsurface structure. This structure consists of an outer non-equilibrium layer typical of nitrogen implantation (containing in excess of 20 at.% nitrogen) backed by a substantial diffusion zone of much lower nitrogen content. The relationship between implantation temperature and the resultant subsurface microstructure is explored. (orig.)

Risk of pacemaker implantation subsequent to radiotherapy for early-stage breast cancer in Denmark, 1982-2005

DEFF Research Database (Denmark)

Rehammar, Jens Christian; Videbaek, L.; Brock Johansen, J.

2015-01-01

. Objectives: The aim of this study was to examine the risk of severe conduction abnormalities evaluated by implantation of a pacemaker, subsequent to breast cancer radiotherapy. Methods: From the database of the Danish Breast Cancer Collaborative Group, we identified women treated with radiotherapy for early......-stage breast cancer in Denmark from 1982 to 2005. By record linkage to the Danish Pacemaker and ICD Registry information was retrieved on pacemaker implants subsequent to radiotherapy. Rate ratios (RR) of pacemaker implantation for left versus right sided breast cancer were calculated. Results: Among 18......,308 women treated with radiotherapy for early-stage breast cancer, 179 women had a pacemaker implanted subsequent to radiotherapy, 90 in 9,315 left sided and 89 in 8,993 right sided breast cancers. The unadjusted RR was 1.02 (0.76-1.36 95% CI, p=0.91) and the RR adjusted for year, age and time since...

3D finite element analysis of immediate loading of single wide versus double implants for replacing mandibular molar

Directory of Open Access Journals (Sweden)

Shrikar R Desai

2013-01-01

Full Text Available Purpose: The purpose of this finite element study was to compare the stresses, strains, and displacements of double versus single implant in immediate loading for replacing mandibular molar. Materials and Methods: Two 3D FEM (finite element method models were made to simulate implant designs. The first model used 5-mm-wide diameter implant to support a single molar crown. The second model used 3.75-3.75 double implant design. Anisotropic properties were assigned to bone model. Each model was analyzed with single force magnitude (100 N in vertical axis. Results: This FEM study suggested that micromotion can be controlled better for double implants compared to single wide-diameter implants. The Von Mises stress for double implant showed 74.44% stress reduction compared to that of 5-mm implant. The Von Mises elastic strain was reduced by 61% for double implant compared to 5-mm implant. Conclusion: Within the limitations of the study, when the mesiodistal space for artificial tooth is more than 12.5 mm, under immediate loading, the double implant support should be considered.

Hydroxyapatite ceramic implants for cranioplasty in children: a single-center experience.

Science.gov (United States)

Zaccaria, Laura; Tharakan, Sasha Job; Altermatt, Stefan

2017-02-01

The use of hydroxyapatite ceramic (HAC) implants for the treatment of skull defects in pediatric patients started 2010 at our institution. Ceramic implants facilitate osteoblast migration and therefore optimize osteointegration with the host bone. The purpose of this study is to report a single-center experience with this treatment modality. A retrospective review of all patients from July 2010 through June 2014 undergoing a cranioplasty using hydroxyapatite ceramic implant and managed at a single institution was performed. Indication for cranioplasty, the hospital course, and follow-up were reviewed. Bone density was measured in Hounsfield Units (HU) and osteointegration was calculated using Mimics Software® (Mimics Innovation Suite v17.0 Medical, Materialize, Leuven, Belgium). Over the 4-year period, six patients met criteria for the study. Five patients had an osteointegration of nearly 100%. One patient had an incomplete osteointegration with a total bone-implant contact area of 69%. The mean bone density was 2800 HU (2300-3000 HU). Bone density alone is estimated to have a Hounsfield value between 400 and 2000 HU depending on the body region and bone quality. There were no major complications, and the patients were highly satisfied with the esthetical result. Hydroxyapatite ceramic implants for cranioplasty in pediatric patients are a good choice for different indications. The implants show excellent osteointegration and esthetical results.

Different responses to muon implantation in single- and double-stranded DNA

International Nuclear Information System (INIS)

Hubbard, Penny L.; Tani, Akiko; Oganesyan, Vasily S.; Butt, Julea N.; Cottrell, Stephen P.; Jayasooriya, Upali A.

2006-01-01

A model-free analysis of the longitudinal muon spin relaxation of muons implanted into single- and double-stranded DNA samples is reported. These samples show distinctly different responses to implanted muons with discontinuities of the integrated asymmetries at temperatures where these molecules are likely to have onset of molecular and electron dynamics

Single- and double- lumen silicone breast implant integrity: prospective evaluation of MR and US criteria.

Science.gov (United States)

Berg, W A; Caskey, C I; Hamper, U M; Kuhlman, J E; Anderson, N D; Chang, B W; Sheth, S; Zerhouni, E A

1995-10-01

To evaluate the accuracy of magnetic resonance (MR) and ultrasound (US) criteria for breast implant integrity. One hundred twenty-two single-lumen silicone breast implants and 22 bilumen implants were evaluated with surface coil MR imaging and US and surgically removed. MR criteria for implant failure were a collapsed implant shell ("linguine sign"), foci of silicone outside the shell ("noose sign"), and extracapsular gel, US criteria were collapsed shell, low-level echoes within the gel, and "snowstorm" echoes of extracapsular silicone. Among single-lumen implants, MR imaging depicted 39 of 40 ruptures, 14 of 28 with minimal leakage; 49 of 54 intact implants were correctly interpreted. US depicted 26 of 40 ruptured implants, four of 28 with minimal leakage, and 30 of 54 intact implants. Among bilumen implants, MR imaging depicted four of five implants with rupture of both lumina and nine of 10 as intact; US depicted one rupture and helped identify two of 10 as intact. Mammography accurately depicted the status of 29 of 30 bilumen implants with MR imaging correlation. MR imaging depicts implant integrity more accurately than US; neither method reliably depicts minimal leakage with shell collapse. Mammography is useful in screening bilumen implant integrity.

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....

Breast implants following mastectomy in women with early-stage breast cancer: prevalence and impact on survival

International Nuclear Information System (INIS)

Le, Gem M; O'Malley, Cynthia D; Glaser, Sally L; Lynch, Charles F; Stanford, Janet L; Keegan, Theresa HM; West, Dee W

2005-01-01

Few studies have examined the effect of breast implants after mastectomy on long-term survival in breast cancer patients, despite growing public health concern over potential long-term adverse health effects. We analyzed data from the Surveillance, Epidemiology and End Results Breast Implant Surveillance Study conducted in San Francisco–Oakland, in Seattle–Puget Sound, and in Iowa. This population-based, retrospective cohort included women younger than 65 years when diagnosed with early or unstaged first primary breast cancer between 1983 and 1989, treated with mastectomy. The women were followed for a median of 12.4 years (n = 4968). Breast implant usage was validated by medical record review. Cox proportional hazards models were used to estimate hazard rate ratios for survival time until death due to breast cancer or other causes for women with and without breast implants, adjusted for relevant patient and tumor characteristics. Twenty percent of cases received postmastectomy breast implants, with silicone gel-filled implants comprising the most common type. Patients with implants were younger and more likely to have in situ disease than patients not receiving implants. Risks of breast cancer mortality (hazard ratio, 0.54; 95% confidence interval, 0.43–0.67) and nonbreast cancer mortality (hazard ratio, 0.59; 95% confidence interval, 0.41–0.85) were lower in patients with implants than in those patients without implants, following adjustment for age and year of diagnosis, race/ethnicity, stage, tumor grade, histology, and radiation therapy. Implant type did not appear to influence long-term survival. In a large, population-representative sample, breast implants following mastectomy do not appear to confer any survival disadvantage following early-stage breast cancer in women younger than 65 years old

Esthetic evaluation of single-tooth implants in the anterior maxilla following autologous bone augmentation.

Science.gov (United States)

Hof, M; Pommer, B; Strbac, G D; Sütö, D; Watzek, G; Zechner, W

2013-08-01

Autologous bone augmentation to rebuild compromised alveolar ridge contour prior to implant placement allows for favorable three-dimensional implant positioning to achieve optimum implant esthetics. The aim of the present study was to evaluate peri-implant soft tissue conditions around single-tooth implants following bone grafts in the esthetic zone of the maxilla. Sixty patients underwent autologous bone augmentation of deficient maxillary sites prior to placement of 85 implants in the esthetic zone. In case of multiple implants per patient, one implant was randomly selected. Objective evaluation of 60 single-tooth implants was performed using the Pink-Esthetic-Score (PES) and Papilla Index (PI) and supplemented by subjective patient evaluation, as well as clinical and radiologic examination. Objective ratings of implant esthetics were satisfactory (median PES: 11, median PI: 2) and significantly correlated with high patient satisfaction (mean VAS score: 80%). Both esthetic indices demonstrated respectable levels of inter- as well as intra-observer agreement. Poor implant esthetics (low PES and PI ratings) were significantly associated with increased anatomic crown height, while no influence of horizontal implant-tooth distance could be found. The present investigation indicates that favorable esthetic results may be achieved in the augmented anterior maxilla. However, bony reconstruction of compromised alveolar ridges does not guarantee optimum implant esthetics. © 2011 John Wiley & Sons A/S.

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.

Formation of oriented nitrides by N+ ion implantation in iron single crystals

International Nuclear Information System (INIS)

Costa, A.R.G.; Silva, R.C. da; Ferreira, L.P.; Carvalho, M.D.; Silva, C.; Franco, N.; Godinho, M.

2014-01-01

Iron single crystals were implanted with nitrogen at room temperature, with a fluence of 5×10 17 cm −2 and 50 keV energy, to produce iron nitride phases and characterize the influence of the crystal orientation. The stability and evolution of the nitride phases and diffusion of implanted nitrogen were studied as a function of successive annealing treatments at 250 °C in vacuum. The composition, structure and magnetic properties were characterized using RBS/channeling, X-Ray Diffraction, Magnetic Force Microscopy, Magneto-optical Kerr Effect and Conversion Electron Mössbauer Spectroscopy. In the as-implanted state the formation of Fe 2 N phase was clearly identified in all single crystals. This phase is not stable at 250 °C and annealing at this temperature promotes the formation of ε-Fe 3 N, or γ′-Fe 4 N, depending on the orientation of the substrate. - Highlights: • Oriented magnetic iron nitrides were obtained by nitrogen implantation into iron single crystals. • The stable magnetic nitride phase at 250 °C depends on the orientation of the host single crystal, being γ'-Fe 4 N or ε-Fe 3 N. • The easy magnetization axis was found to lay in the (100) plane for cubic γ'-Fe 4 N and out of (100) plane for hexagonal ε-Fe 3 N

A positive bacterial culture during re-implantation is associated with a poor outcome in two-stage exchange arthroplasty for deep infection.

Science.gov (United States)

Akgün, D; Müller, M; Perka, C; Winkler, T

2017-11-01

The aim of this study was to identify the incidence of positive cultures during the second stage of a two-stage revision arthroplasty and to analyse the association between positive cultures and an infection-free outcome. This single-centre retrospective review of prospectively collected data included patients with a periprosthetic joint infection (PJI) of either the hip or the knee between 2013 and 2015, who were treated using a standardised diagnostic and therapeutic algorithm with two-stage exchange. Failure of treatment was assessed according to a definition determined by a Delphi-based consensus. Logistic regression analysis was performed to assess the predictors of positive culture and risk factors for failure. The mean follow-up was 33 months (24 to 48). A total of 163 two-stage revision arthroplasties involving 84 total hip arthroplasties (THAs) and 79 total knee arthroplasties (TKAs) were reviewed. In 27 patients (16.6%), ≥ 1 positive culture was identified at re-implantation and eight (29.6%) of these subsequently failed compared with 20 (14.7%) patients who were culture-negative. The same initially infecting organism was isolated at re-implantation in nine of 27 patients (33.3%). The organism causing re-infection in none of the patients was the same as that isolated at re-implantation. The risk of the failure of treatment was significantly higher in patients with a positive culture (odds ratio (OR) 1.7; 95% confidence interval (CI) 1.0 to 3.0; p = 0.049) and in patients with a higher Charlson Comorbidity Index (OR 1.5; 95% CI 1.6 to 1.8; p = 0.001). Positive culture at re-implantation was independently associated with subsequent failure. Surgeons need to be aware of this association and should consider the medical optimisation of patients with severe comorbidities both before and during treatment. Cite this article: Bone Joint J 2017;99-B:1490-5. ©2017 The British Editorial Society of Bone & Joint Surgery.

Oxygen recoil implant from SiO2 layers into single-crystalline silicon

International Nuclear Information System (INIS)

Wang, G.; Chen, Y.; Li, D.; Oak, S.; Srivastav, G.; Banerjee, S.; Tasch, A.; Merrill, P.; Bleiler, R.

2001-01-01

It is important to understand the distribution of recoil-implanted atoms and the impact on device performance when ion implantation is performed at a high dose through surface materials into single crystalline silicon. For example, in ultralarge scale integration impurity ions are often implanted through a thin layer of screen oxide and some of the oxygen atoms are inevitably recoil implanted into single-crystalline silicon. Theoretical and experimental studies have been performed to investigate this phenomenon. We have modified the Monte Carlo ion implant simulator, UT-Marlowe (B. Obradovic, G. Wang, Y. Chen, D. Li, C. Snell, and A. F. Tasch, UT-MARLOWE Manual, 1999), which is based on the binary collision approximation, to follow the full cascade and to dynamically modify the stoichiometry of the Si layer as oxygen atoms are knocked into it. CPU reduction techniques are used to relieve the demand on computational power when such a full cascade simulation is involved. Secondary ion mass spectrometry (SIMS) profiles of oxygen have been carefully obtained for high dose As and BF 2 implants at different energies through oxide layers of various thicknesses, and the simulated oxygen profiles are found to agree very well with the SIMS data. [copyright] 2001 American Institute of Physics

Improved generation of single nitrogen-vacancy centers in diamond by ion implantation

Energy Technology Data Exchange (ETDEWEB)

Naydenov, Boris; Beck, Johannes; Steiner, Matthias; Balasubramanian, Gopalakrishnan; Jelezko, Fedor; Wrachtrup, Joerg [3. Institute of Physics, University of Stuttgart (Germany); Richter, Vladimir; Kalish, Rafi [Solid State Institute, Technion City, Haifa (Israel); Achard, Jocelyn [Laboratoire d' Ingenieurie des Materiaux et des Hautes Pressions, CNRS, Villetaneuse (France)

2010-07-01

Nitrogen-vacancy (NV) centers in diamond have recently attracted the attention of many research groups due to their possible application as quantum bits (qubits), ultra low magnetic field sensors and single photon sources. These color centers can be produced by nitrogen ion implantation, although the yield is usually below 5 % at low ion energies. Here we report an increase of the NV production efficiency by subsequently implanting carbon ions in the area of implanted nitrogen ions. This method improves the production yield by more than 50 %. We also show that very low nitrogen concentration (below 0.1 ppb) in diamond can be determined by converting the intrinsic nitrogen atoms to single NV centers and detecting the latter using a confocal microscope.

Esthetic outcome for maxillary anterior single implants assessed by different dental specialists.

Science.gov (United States)

Al-Dosari, Abdullah; Al-Rowis, Ra'ed; Moslem, Feras; Alshehri, Fahad; Ballo, Ahmed M

2016-10-01

The aim of this study was to assess the esthetic outcome of maxillary anterior single implants by comparing the esthetic perception of dental professionals and patients. Twenty-three patients with single implants in the esthetic zone were enrolled in this study. Dentists of four different dental specialties (Three orthodontists, three oral surgeons, three prosthodontists, and three periodontists) evaluated the pink esthetic score (PES)/white esthetic score (WES) for 23 implant-supported single restorations. The satisfactions of the patients on the esthetic outcome of the treatment have been evaluated according to the visual analog scale (VAS). The mean total PES/WES was 12.26 ± 4.76. The mean PES was 6.45 ± 2.78 and mean WES was 5.80 ± 2.82. There was a statistically significant difference among the different specialties for WES ( P esthetic perception, thereby providing rationales for involving patients in the treatment plan to achieve higher levels of patient satisfaction.

Comparison of migration behavior between single and dual lag screw implants for intertrochanteric fracture fixation

Directory of Open Access Journals (Sweden)

Katonis Pavlos G

2009-05-01

Full Text Available Abstract Background Lag screw cut-out failure following fixation of unstable intertrochanteric fractures in osteoporotic bone remains an unsolved challenge. This study tested if resistance to cut-out failure can be improved by using a dual lag screw implant in place of a single lag screw implant. Migration behavior and cut-out resistance of a single and a dual lag screw implant were comparatively evaluated in surrogate specimens using an established laboratory model of hip screw cut-out failure. Methods Five dual lag screw implants (Endovis, Citieffe and five single lag screw implants (DHS, Synthes were tested in the Hip Implant Performance Simulator (HIPS of the Legacy Biomechanics Laboratory. This model simulated osteoporotic bone, an unstable fracture, and biaxial rocking motion representative of hip loading during normal gait. All constructs were loaded up to 20,000 cycles of 1.45 kN peak magnitude under biaxial rocking motion. The migration kinematics was continuously monitored with 6-degrees of freedom motion tracking system and the number of cycles to implant cut-out was recorded. Results The dual lag screw implant exhibited significantly less migration and sustained more loading cycles in comparison to the DHS single lag screw. All DHS constructs failed before 20,000 cycles, on average at 6,638 ± 2,837 cycles either by cut-out or permanent screw bending. At failure, DHS constructs exhibited 10.8 ± 2.3° varus collapse and 15.5 ± 9.5° rotation around the lag screw axis. Four out of five dual screws constructs sustained 20,000 loading cycles. One dual screw specimens sustained cut-out by medial migration of the distal screw after 10,054 cycles. At test end, varus collapse and neck rotation in dual screws implants advanced to 3.7 ± 1.7° and 1.6 ± 1.0°, respectively. Conclusion The single and double lag screw implants demonstrated a significantly different migration resistance in surrogate specimens under gait loading simulation with

Influence of the Diameter of Dental Implants Replacing Single Molars: 3- to 6-Year Follow-Up.

Science.gov (United States)

Mendonça, Jose Alfredo; Senna, Plinio Mendes; Francischone, Carlos Eduardo; Francischone Junior, Carlos Eduardo; Sotto-Maior, Bruno Salles

The aim of this study was to evaluate the influence of the implant diameter on marginal bone remodeling around dental implants replacing single molars after a follow-up period of 3 to 6 years. Patients who received dental implants with an external hexagon platform in healed sites to support a single metal-ceramic crown in the molar region were recalled to the office. The implantation sites and implant length information were recorded, and the implants were divided according to the implant diameter: regular (RP) or wide (WP). Each implant was assessed by digital periapical radiography, using a sensor holder for the paralleling technique. The marginal bone remodeling was determined as the distance from the implant platform to the first bone-to-implant contact, and the known implant length was used to calibrate the images in the computer software. The follow-up measurements were compared with those obtained from the radiograph taken at the time of prosthetic loading to determine the late bone remodeling. The independent t test was used to compare data. A total of 67 implants from 46 patients were evaluated with a mean follow-up period of 4.5 ± 1.0 years. The RP group comprised 36 implants from 29 patients (mean age: 58.3 ± 10.6 years), while 31 implants from 17 patients (mean age: 56.9 ± 11.5 years) were included in the WP group. The RP group presented lower survival rates (86.1%) than the WP group (100.0%). Similar marginal bone loss (P implants exhibited lower incidence failures, the bone levels were similar after the prosthetic loading around regular- and wide-diameter implants supporting single molar crowns.

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.

Heavy doping of CdTe single crystals by Cr ion implantation

Science.gov (United States)

Popovych, Volodymyr D.; Böttger, Roman; Heller, Rene; Zhou, Shengqiang; Bester, Mariusz; Cieniek, Bogumil; Mroczka, Robert; Lopucki, Rafal; Sagan, Piotr; Kuzma, Marian

2018-03-01

Implantation of bulk CdTe single crystals with high fluences of 500 keV Cr+ ions was performed to achieve Cr concentration above the equilibrium solubility limit of this element in CdTe lattice. The structure and composition of the implanted samples were studied using secondary ion mass spectrometry (SIMS), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS) to characterize the incorporation of chromium into the host lattice and to investigate irradiation-induced damage build-up. It was found that out-diffusion of Cr atoms and sputtering of the targets alter the depth distribution and limit concentration of the projectile ions in the as-implanted samples. Appearance of crystallographically oriented, metallic α-Cr nanoparticles inside CdTe matrix was found after implantation, as well as a strong disorder at the depth far beyond the projected range of the implanted ions.

Comparisons of single-stage and two-stage approaches to genomic selection.

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Schulz-Streeck, Torben; Ogutu, Joseph O; Piepho, Hans-Peter

2013-01-01

Genomic selection (GS) is a method for predicting breeding values of plants or animals using many molecular markers that is commonly implemented in two stages. In plant breeding the first stage usually involves computation of adjusted means for genotypes which are then used to predict genomic breeding values in the second stage. We compared two classical stage-wise approaches, which either ignore or approximate correlations among the means by a diagonal matrix, and a new method, to a single-stage analysis for GS using ridge regression best linear unbiased prediction (RR-BLUP). The new stage-wise method rotates (orthogonalizes) the adjusted means from the first stage before submitting them to the second stage. This makes the errors approximately independently and identically normally distributed, which is a prerequisite for many procedures that are potentially useful for GS such as machine learning methods (e.g. boosting) and regularized regression methods (e.g. lasso). This is illustrated in this paper using componentwise boosting. The componentwise boosting method minimizes squared error loss using least squares and iteratively and automatically selects markers that are most predictive of genomic breeding values. Results are compared with those of RR-BLUP using fivefold cross-validation. The new stage-wise approach with rotated means was slightly more similar to the single-stage analysis than the classical two-stage approaches based on non-rotated means for two unbalanced datasets. This suggests that rotation is a worthwhile pre-processing step in GS for the two-stage approaches for unbalanced datasets. Moreover, the predictive accuracy of stage-wise RR-BLUP was higher (5.0-6.1%) than that of componentwise boosting.

Falling Leaves Inspired ZnO Nanorods-Nanoslices Hierarchical Structure for Implant Surface Modification with Two Stage Releasing Features.

Science.gov (United States)

Liao, Hang; Miao, Xinxin; Ye, Jing; Wu, Tianlong; Deng, Zhongbo; Li, Chen; Jia, Jingyu; Cheng, Xigao; Wang, Xiaolei

2017-04-19

Inspired from falling leaves, ZnO nanorods-nanoslices hierarchical structure (NHS) was constructed to modify the surfaces of two widely used implant materials: titanium (Ti) and tantalum (Ta), respectively. By which means, two-stage release of antibacterial active substances were realized to address the clinical importance of long-term broad-spectrum antibacterial activity. At early stages (within 48 h), the NHS exhibited a rapid releasing to kill the bacteria around the implant immediately. At a second stage (over 2 weeks), the NHS exhibited a slow releasing to realize long-term inhibition. The excellent antibacterial activity of ZnO NHS was confirmed once again by animal test in vivo. According to the subsequent experiments, the ZnO NHS coating exhibited the great advantage of high efficiency, low toxicity, and long-term durability, which could be a feasible manner to prevent the abuse of antibiotics on implant-related surgery.

Comparison of single-stage and temperature-phased two-stage anaerobic digestion of oily food waste

International Nuclear Information System (INIS)

Wu, Li-Jie; Kobayashi, Takuro; Li, Yu-You; Xu, Kai-Qin

2015-01-01

Highlights: • A single-stage and two two-stage anaerobic systems were synchronously operated. • Similar methane production 0.44 L/g VS_a_d_d_e_d from oily food waste was achieved. • The first stage of the two-stage process became inefficient due to serious pH drop. • Recycle favored the hythan production in the two-stage digestion. • The conversion of unsaturated fatty acids was enhanced by recycle introduction. - Abstract: Anaerobic digestion is an effective technology to recover energy from oily food waste. A single-stage system and temperature-phased two-stage systems with and without recycle for anaerobic digestion of oily food waste were constructed to compare the operation performances. The synchronous operation indicated the similar ability to produce methane in the three systems, with a methane yield of 0.44 L/g VS_a_d_d_e_d. The pH drop to less than 4.0 in the first stage of two-stage system without recycle resulted in poor hydrolysis, and methane or hydrogen was not produced in this stage. Alkalinity supplement from the second stage of two-stage system with recycle improved pH in the first stage to 5.4. Consequently, 35.3% of the particulate COD in the influent was reduced in the first stage of two-stage system with recycle according to a COD mass balance, and hydrogen was produced with a percentage of 31.7%, accordingly. Similar solids and organic matter were removed in the single-stage system and two-stage system without recycle. More lipid degradation and the conversion of long-chain fatty acids were achieved in the single-stage system. Recycling was proved to be effective in promoting the conversion of unsaturated long-chain fatty acids into saturated fatty acids in the two-stage system.

A comparison of buried oxide characteristics of single and multiple implant SIMOX and bond and etch back wafers

International Nuclear Information System (INIS)

Annamalai, N.K.; Bockman, J.F.; McGruer, N.E.; Chapski, J.

1990-01-01

The current through the buried oxides of single and multiple implant SIMOX and bond and etch back silicon-on-insulator (BESOI) wafers were measured as a function of radiation dose. From these measurements, conductivity and static capacitances were derived. High frequency capacitances were also measured. Leakage current through the buried oxide of multiple implant SIMOX is considerably less than that of single implant SIMOX (more than an order of magnitude). High frequency and static capacitances, as a function of total dose, were used to study the buried oxide---top silicon interface and the buried oxide---bottom silicon interface. Multiple implant had fewer interface traps than single implant at pre-rad and after irradiation

A new computationally-efficient two-dimensional model for boron implantation into single-crystal silicon

International Nuclear Information System (INIS)

Klein, K.M.; Park, C.; Yang, S.; Morris, S.; Do, V.; Tasch, F.

1992-01-01

We have developed a new computationally-efficient two-dimensional model for boron implantation into single-crystal silicon. This paper reports that this new model is based on the dual Pearson semi-empirical implant depth profile model and the UT-MARLOWE Monte Carlo boron ion implantation model. This new model can predict with very high computational efficiency two-dimensional as-implanted boron profiles as a function of energy, dose, tilt angle, rotation angle, masking edge orientation, and masking edge thickness

Control of Single-Stage Single-Phase PV inverter

DEFF Research Database (Denmark)

Ciobotaru, Mihai; Teodorescu, Remus; Blaabjerg, Frede

2005-01-01

In this paper the issue of control strategies for single-stage photovoltaic (PV) inverter is addressed. Two different current controllers have been implemented and an experimental comparison between them has been made. A complete control structure for the single-phase PV system is also presented......-forward; - and the grid current controller implemented in two different ways, using the classical proportional integral (PI) and the novel proportional resonant (PR) controllers. The control strategy was tested experimentally on 1.5 kW PV inverter....

Risk of pacemaker or implantable cardioverter defibrillator after radiotherapy for early-stage breast cancer in Denmark, 1982-2005

DEFF Research Database (Denmark)

Rehammar, Jens Christian; Johansen, Jens Brock; Jensen, Maj-Britt

2017-01-01

BACKGROUND AND PURPOSE: To examine the risk of cardiac conduction abnormalities or severe ventricular arrhythmias requiring implantation of a cardiac implantable electronic device (CIED), either a pacemaker or an implantable cardioverter-defibrillator, subsequent to breast cancer (BC) radiotherapy...... (RT). MATERIAL AND METHODS: All women treated for early-stage BC in Denmark from 1982 to 2005 were identified from the Danish Breast Cancer Cooperative Group. By record linkage to the Danish Pacemaker and ICD Registry information was retrieved on CIED implants subsequent to RT. Standardized incidence...

Effect of connective tissue grafting on peri-implant tissue in single immediate implant sites : A RCT

NARCIS (Netherlands)

Zuiderveld, Elise G; Meijer, Henny J A; den Hartog, Laurens; Vissink, Arjan; Raghoebar, Gerry M

AimTo assess the effect of connective tissue grafting on the mid-buccal mucosal level (MBML) of immediately placed and provisionalized single implants in the maxillofacial aesthetic zone. Materials and methodsSixty patients with a failing tooth were provided with an immediately placed and

Hydrogen- and helium-implanted silicon: Low-temperature positron-lifetime studies

DEFF Research Database (Denmark)

Mäkinen, S.; Rajainmäki, H.; Linderoth, Søren

1991-01-01

High-purity single-crystal samples of float-zoned Si have been implanted with 6.95-MeV protons and with 25-MeV 3He2 ions at 15 K, and the positron-lifetime technique has been used to identify the defects created in the samples, and to study the effects of H and He on the annealing of point defects...... in Si. The results have been compared with those of proton-irradiated Si. A 100–300-K annealing stage was clearly observed in hydrogen (H+) -implanted Si, and this stage was almost identical to that in the p-irradiated Si. The final annealing state of the H+-implanted Si started at about 400 K......, and it is connected to annealing out of negatively charged divacancy-oxygen pairs. This stage was clearly longer than that for the p-irradiated Si, probably due to the breakup of Si-H bonds at about 550 K. The 100-K annealing stage was not seen with the He-implanted samples. This has been explained by assuming...

EXPERIMENTAL RESEARCH OF REGENERATIVE FEATURES IN BONE TISSUES AROUND IMPLANTS AFTER ONE-STAGE BILATERAL TOTAL HIP REPLACEMENT

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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.

Transition from failing dentition to complete-arch implant rehabilitation with a staged approach: a 3-year clinical report.

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Papaspyridakos, Panos; Chronopoulos, Vasilios

2014-09-01

The transition of patients from failing dentition to complete-arch implant rehabilitation often means that the patient is rendered edentulous and has to wear a removable complete denture for a time. Many patients find this objectionable. A staged treatment approach provides a fixed interim prosthesis for use throughout the rehabilitation process, allowing patient comfort and prosthodontic control. This clinical report describes a staged approach protocol with a new type of interim prosthesis. The prosthesis is supported by hopeless teeth and the soft tissues of the maxillary tuberosities and mandibular retromolar pads for the complete-arch implant rehabilitation of a patient with failing dentition. This protocol allows for a fixed interim prosthesis with combined tooth and mucosa or implant support during the entire rehabilitation process, thus avoiding the use of complete dentures. The implants and prostheses were functioning successfully after 3 years of clinical service. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Complications and Mortality of Single Versus Dual Chamber Implantable Cardioverter Defibrillators

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Ataallah Bagherzadeh

2006-04-01

Full Text Available Background: The implantable cardioverter defibrillators (ICDs are increasingly being used as a treatment modality for life threatening tachyarrhythmia. The purpose of this study was to compare the frequency of complications and mortality between single-chamber and dual-chamber ICD implantation in Shahid Rajaie cardiovascular center. Methods and results: Between January 2000 and December 2004, 234 patients received ICD by a percutaneous transvenous approach and were followed for 33 ± 23 months. The cumulative incidence of complications was 9.4% over the follow-up period. There was no significant difference in overall complication rate between single chamber (VR and dual chamber (DR ICD groups in the follow-up period (P= 0.11. The risk of complications did not have any statistically significant difference in secondary versus primary prevention groups (P=0.06. The complications were not associated with the severity of left ventricular systolic dysfunction (P=0.16.The frequency of lead-related complications was higher in dual chamber ICDs in comparison with single chamber ICDs (P=0.02. There was no significant difference in mortality between different sex groups (P=0.37, different indications for ICD implantation (P=0.43 or between VR and DR ICD groups (P= 0.55. Predictors of mortality were NYHA class III or more (P65 years (P=0.011 and LVEF<30% (P<0.001. The mortality in patients with CAD and DCM were significantly higher than those with other structural heart diseases (P=0.001. Conclusions: Close monitoring of patients during the first 2 month after ICD implantation is recommended because the majority of complications occur early after the procedure.

Structural and magnetic properties of Tb implanted ZnO single crystals

International Nuclear Information System (INIS)

Zhou Shengqiang; Potzger, K.; Muecklich, A.; Eichhorn, F.; Helm, M.; Skorupa, W.; Fassbender, J.

2008-01-01

ZnO single crystals have been implanted with Tb ions. For an atomic concentration of 1.5%, annealing at 823 K leads to an increase of the saturation magnetization per implanted Tb ion up to 1.8 μ B at room temperature. Structural investigations revealed no secondary phase formation, but the out-diffusion of Tb. No significant evidence is found for Tb substituting Zn sites either in the as-implanted or annealed samples. However, indications for the existence of a small amount of Tb nanoclusters however have been found using magnetization versus temperature measurements. The ferromagnetic properties disappear completely upon annealing at 1023 K. This behavior is related to the formation of oxide complexes or nanoparticles

Two-stage revision surgery with preformed spacers and cementless implants for septic hip arthritis: a prospective, non-randomized cohort study

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Logoluso Nicola

2011-05-01

Full Text Available Abstract Background Outcome data on two-stage revision surgery for deep infection after septic hip arthritis are limited and inconsistent. This study presents the medium-term results of a new, standardized two-stage arthroplasty with preformed hip spacers and cementless implants in a consecutive series of adult patients with septic arthritis of the hip treated according to a same protocol. Methods Nineteen patients (20 hips were enrolled in this prospective, non-randomized cohort study between 2000 and 2008. The first stage comprised femoral head resection, debridement, and insertion of a preformed, commercially available, antibiotic-loaded cement hip spacer. After eradication of infection, a cementless total hip arthroplasty was implanted in the second stage. Patients were assessed for infection recurrence, pain (visual analog scale [VAS] and hip joint function (Harris Hip score. Results The mean time between first diagnosis of infection and revision surgery was 5.8 ± 9.0 months; the average duration of follow up was 56.6 (range, 24 - 104 months; all 20 hips were successfully converted to prosthesis an average 22 ± 5.1 weeks after spacer implantation. Reinfection after total hip joint replacement occurred in 1 patient. The mean VAS pain score improved from 48 (range, 35 - 84 pre-operatively to 18 (range, 0 - 38 prior to spacer removal and to 8 (range, 0 - 15 at the last follow-up assessment after prosthesis implantation. The average Harris Hip score improved from 27.5 before surgery to 61.8 between the two stages to 92.3 at the final follow-up assessment. Conclusions Satisfactory outcomes can be obtained with two-stage revision hip arthroplasty using preformed spacers and cementless implants for prosthetic hip joint infections of various etiologies.

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...

Esthetic evaluation of maxillary single-tooth implants in the esthetic zone

Science.gov (United States)

Cho, Hae-Lyung; Lee, Jae-Kwan; Um, Heung-Sik

2010-01-01

Purpose The aim of this study is to assess the influence exerted by the observer's dental specialization and compare patients' opinion with observers' opinion of the esthetics of maxillary single-tooth implants in the esthetic zone. Methods Forty-one adult patients, who were treated with a single implant in the esthetic zone, were enrolled in this study. Eight observers (2 periodontists, 2 prosthodontists, 2 orthodontists and 2 senior dental students) applied the pink esthetic score (PES)/white esthetic score (WES) to 41 implant-supported single restorations twice with an interval of 4 weeks. We used a visual analog scale (VAS) to assess the patient's satisfaction with the treatment outcome from an esthetic point of view. Results In the PES/WES, very good and moderate intraobserver agreements were noted between the first and second rating. The mean total PES/WES was 11.19 ± 3.59. The mean PES was 5.17 ± 2.29 and mean WES was 6.02 ± 1.96. In the total PES/WES, the difference between the groups was not significant. However, in the WES, the difference between the groups was significant and prosthodontists were found to have assigned poorer ratings than the other groups. Periodontists gave higher ratings than prosthodontists and senior dental students. Orthodontists were clearly more critical than the other observers. The statistical analysis revealed statistically significant correlation between patients' esthetic perception and dentists' perception of the anterior tooth. However, the correlation between the total PES/WES and the VAS score for the first premolar was not statistically significant. Conclusions The PES/WES is an objective tool in rating the esthetics of implant supported single crowns and adjacent soft tissues. Orthodontists were the most critical observers, while periodontists were more generous than other observers. The statistical analysis revealed a statistically significant correlation between patients' esthetic perception and dentists

Clinical Outcome After 8 to 10 Years of Immediately Restored Single Implants Placed in Extraction Sockets and Healed Ridges.

Science.gov (United States)

Raes, Stefanie; Cosyn, Jan; Noyelle, Anabel; Raes, Filiep; De Bruyn, Hugo

Recent systematic reviews point to the scarcity of single implants followed up longer than 5 years, and the incidence of biologic/technical complications is underreported. This prospective follow-up study documents 8- to 10-year clinical outcomes of immediately restored single implants in extraction sockets (immediate implant treatment [IIT]) and healed bone (conventional implant treatment [CIT]). Patients received a single, chemically modified, moderately rough titanium implant and a provisional crown on the day of surgery in the anterior maxilla (second premolar to second premolar). Provisional crowns were replaced by permanent crowns after 10 weeks. Implant survival, complications, crestal bone changes, plaque score, probing depth, and bleeding on probing were regularly recorded up to 10 years of follow-up. Of 16 patients who underwent IIT, 11 could be evaluated after 8 years. Of the 23 patients who received an implant in healed bone, 18 were finally evaluated. One implant failed in the IIT group at 12 weeks; all implants survived in the CIT group; 38% of the patients experienced at least one complication; 10% had one or more biologic complications, whereas 31% experienced one or more technical complications. There were no significant changes in crestal bone level from 1 to ≥ 8 years of follow-up for either group or between IIT and CIT at any time point (P ≥ .129). Only 6.9% (2 of 29) implants demonstrated progressive bone loss > 2 mm combined with pockets ≥ 6 mm. Immediately restored single implants in extraction sockets and healed ridges demonstrate good long-term outcomes in terms of implant survival, crestal bone loss, and peri-implant health. However, biologic and especially technical complications are common.

Evaluation of the influence of implant placement timing on the esthetic outcomes of single tooth implant treatment in the anterior maxilla: A retrospective study.

Science.gov (United States)

Arora, Himanshu; Ivanovski, Saso

2018-05-15

The purpose of this retrospective study was to investigate the influence of implant placement timing on the esthetic outcomes for single implants in the anterior maxilla. One hundred and ten patients (48 males; 62 females) who received a single-tooth implant after extraction either immediately (Type 1); after 4-8 weeks (Type 2); after 8-16 weeks (Type 3); or more than 16 weeks (Type 4) were evaluated in terms of esthetic outcomes after a mean post-placement interval of 26.3 months (range 12-116). Esthetic outcomes were measured using the Pink and White Esthetic Score (PES; WES). Stepwise regression analysis was performed to analyze the effect of timing of placement, as well as patient demographics and other clinical parameters on the esthetic outcomes. No statistically significantly differences in PES were found between the various treatment modalities with Type 1 implants (n = 33) scoring 10.58 ± 1.65 (median: 11), followed by 10.36 ± 2.09 (median: 10.5), 9.68 ± 2.43 (median: 10), and 9.63 ± 2.21 (median: 10) for Type 2 (n = 14), Type 3 (n = 19), and Type 4 (n = 44), respectively. For immediate implants, a trend towards better esthetic outcomes was observed when implant placement was done flaplessly in cases with intact buccal bone (Type 1A, median PES 11) as compared to cases with partial/complete missing buccal plates where a flap was raised (Type 1B, median PES 10). Overall, the only parameter that influenced esthetic outcomes (as measured by PES) was gender, with females having significantly superior results. The median WES was 8 and 96% of the crowns were deemed esthetically acceptable, with crowns placed by specialist prosthodontists yielding higher scores than those placed by general practitioners. Single tooth implants in the anterior maxilla showed satisfactory outcomes when measured with objective esthetic criteria. Timing of implant placement did not significantly influence the esthetic outcomes, although a trend

Marginal Bone Remodeling around healing Abutment vs Final Abutment Placement at Second Stage Implant Surgery: A 12-month Randomized Clinical Trial.

Science.gov (United States)

Nader, Nabih; Aboulhosn, Maissa; Berberi, Antoine; Manal, Cordahi; Younes, Ronald

2016-01-01

The periimplant bone level has been used as one of the criteria to assess the success of dental implants. It has been documented that the bone supporting two-piece implants undergoes resorption first following the second-stage surgery and later on further to abutment connection and delivery of the final prosthesis. The aim of this multicentric randomized clinical trial was to evaluate the crestal bone resorption around internal connection dental implants using a new surgical protocol that aims to respect the biological distance, relying on the benefit of a friction fit connection abutment (test group) compared with implants receiving conventional healing abutments at second-stage surgery (control group). A total of partially edentulous patients were consecutively treated at two private clinics, with two adjacent two-stage implants. Three months after the first surgery, one of the implants was randomly allocated to the control group and was uncovered using a healing abutment, while the other implant received a standard final abutment and was seated and tightened to 30 Ncm. At each step of the prosthetic try-in, the abutment in the test group was removed and then retightened to 30 Ncm. Horizontal bone changes were assessed using periapical radiographs immediately after implant placement and at 3 (second-stage surgery), 6, 9 and 12 months follow-up examinations. At 12 months follow-up, no implant failure was reported in both groups. In the control group, the mean periimplant bone resorption was 0.249 ± 0.362 at M3, 0.773 ± 0.413 at M6, 0.904 ± 0.36 at M9 and 1.047 ± 0.395 at M12. The test group revealed a statistically significant lower marginal bone loss of 20.88% at M3 (0.197 ± 0.262), 22.25% at M6 (0.601 ± 0.386), 24.23% at M9 (0.685 ± 0.341) and 19.2% at M9 (0.846 ± 0.454). The results revealed that bone loss increased over time, with the greatest change in bone loss occurring between 3 and 6 months. Alveolar bone loss was significantly greater in the

3D Printing/Additive Manufacturing Single Titanium Dental Implants: A Prospective Multicenter Study with 3 Years of Follow-Up.

Science.gov (United States)

Tunchel, Samy; Blay, Alberto; Kolerman, Roni; Mijiritsky, Eitan; Shibli, Jamil Awad

2016-01-01

This prospective 3-year follow-up clinical study evaluated the survival and success rates of 3DP/AM titanium dental implants to support single implant-supported restorations. After 3 years of loading, clinical, radiographic, and prosthetic parameters were assessed; the implant survival and the implant-crown success were evaluated. Eighty-two patients (44 males, 38 females; age range 26-67 years) were enrolled in the present study. A total of 110 3DP/AM titanium dental implants (65 maxilla, 45 mandible) were installed: 75 in healed alveolar ridges and 35 in postextraction sockets. The prosthetic restorations included 110 single crowns (SCs). After 3 years of loading, six implants failed, for an overall implant survival rate of 94.5%; among the 104 surviving implant-supported restorations, 6 showed complications and were therefore considered unsuccessful, for an implant-crown success of 94.3%. The mean distance between the implant shoulder and the first visible bone-implant contact was 0.75 mm (±0.32) and 0.89 (±0.45) after 1 and 3 years of loading, respectively. 3DP/AM titanium dental implants seem to represent a successful clinical option for the rehabilitation of single-tooth gaps in both jaws, at least until 3-year period. Further, long-term clinical studies are needed to confirm the present results.

3D Printing/Additive Manufacturing Single Titanium Dental Implants: A Prospective Multicenter Study with 3 Years of Follow-Up

Directory of Open Access Journals (Sweden)

Samy Tunchel

2016-01-01

Full Text Available This prospective 3-year follow-up clinical study evaluated the survival and success rates of 3DP/AM titanium dental implants to support single implant-supported restorations. After 3 years of loading, clinical, radiographic, and prosthetic parameters were assessed; the implant survival and the implant-crown success were evaluated. Eighty-two patients (44 males, 38 females; age range 26–67 years were enrolled in the present study. A total of 110 3DP/AM titanium dental implants (65 maxilla, 45 mandible were installed: 75 in healed alveolar ridges and 35 in postextraction sockets. The prosthetic restorations included 110 single crowns (SCs. After 3 years of loading, six implants failed, for an overall implant survival rate of 94.5%; among the 104 surviving implant-supported restorations, 6 showed complications and were therefore considered unsuccessful, for an implant-crown success of 94.3%. The mean distance between the implant shoulder and the first visible bone-implant contact was 0.75 mm (±0.32 and 0.89 (±0.45 after 1 and 3 years of loading, respectively. 3DP/AM titanium dental implants seem to represent a successful clinical option for the rehabilitation of single-tooth gaps in both jaws, at least until 3-year period. Further, long-term clinical studies are needed to confirm the present results.

Immediate Loading of Single Implants in the Anterior Maxilla: A 1-Year Prospective Clinical Study on 34 Patients

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Miguel Stanley

2017-01-01

Full Text Available Purpose. To present the outcomes of immediately loaded single implants placed in the anterior maxilla. Methods. Over a 2-year period, all patients referred to a private clinic were considered for enrolment in this study. Inclusion criteria were single-tooth placement in postextraction sockets or healed sites of the anterior maxilla. All implants were immediately loaded and followed for a period of 1 year after the placement of definitive crowns. The outcome measures were implant stability, survival, and success. Results. 34 patients were selected and 43 tapered implants with a knife-edge thread design and a nanostructured, calcium-incorporated surface (Anyridge®, Megagen, Gyeongsang, Korea were installed. Two implants were not sufficiently stable at placement (ISQ < 60 and were considered failed for immediate loading; 41 implants had an ISQ ≥ 60 at placement and were immediately loaded. One year after the placement of definitive crowns, no implant failures were reported, for a survival rate of 100%. No biological complications were found, but 2 implants had their prosthetic abutments loosened: the implant success rate was 95.2%. Conclusions. In the present study on the immediate loading of single implants in the anterior maxilla, positive outcomes were reported, with high survival (100% and success (95.2% rates (the present study has been registered in the ISRCTN registry, a publicly available trial register recognized by WHO and ICMJE, with number ISRCTN12935478.

Clinical and radiographic evaluation of early loaded narrow-diameter implants

DEFF Research Database (Denmark)

Maiorana, Carlo; King, Paul; Quaas, Sebastian

2015-01-01

OBJECTIVE: To evaluate the clinical reliability of narrow implants placed in a one-stage procedure and early loaded in the upper and lower incisor region. MATERIAL AND METHODS: This is a prospective, single-arm, multicenter study in which patients with missing natural dentition in upper lateral a...... be considered as a valid solution in the treatment of the localized narrow bony defects in the anterior area with reduced spaces between the natural teeth....... healing period. Clinical and radiographic checks were performed at implant placement, loading, and at the 6, 12, 24, and 36 months follow-up visits. RESULTS: A total of 69 subjects with 97 implants have been included in this study. From surgery to 36 months follow-up, 5.6% of the implants showed bone loss...... loss between loading and the 1-year follow-up visit (Galindo-Moreno et al. 2012). This finding, associated with a stable probing pocket depth and a stable crown-gingiva distance, using a one-stage surgical procedure helps to maintain the integrity of the peri-implant soft tissues. Narrow implants can...

Research on dental implant and its industrialization stage

Science.gov (United States)

Dongjoon, Yang; Sukyoung, Kim

2017-02-01

Bone cell attachment to Ti implant surfaces is the most concerned issue in the clinical implant dentistry. Many attempts to achieve the fast and strong integration between bone and implant have been tried in many ways, such as selection of materials (for example, Ti, ZrO2), shape design of implant (for example, soft tissue level, bone level, taped or conical, etc), and surface modification of implants (for example, roughed. coated, hybrid), etc. Among them, a major consideration is the surface design of dental implants. The surface with proper structural characteristics promotes or induces the desirable responses of cells and tissues. To obtain such surface which has desirable cell and tissue response, a variety of surface modification techniques has been developed and employed for many years. In this review, the method and trend of surface modification will be introduced and explained in terms of the surface topography and chemistry of dental implants.

P-type single-crystalline ZnO films obtained by (N,O) dual implantation through dynamic annealing process

Science.gov (United States)

Zhang, Zhiyuan; Huang, Jingyun; Chen, Shanshan; Pan, Xinhua; Chen, Lingxiang; Ye, Zhizhen

2016-12-01

Single-crystalline ZnO films were grown on a-plane sapphire substrates by plasma-assisted molecular beam epitaxy technique. The films have been implanted with fixed fluence of 120 keV N and 130 keV O ions at 460 °C. Hall measurements show that the dually-implanted single-crystalline ZnO films exhibit p-type characteristics with hole concentration in the range of 2.1 × 1018-1.1 × 1019 cm-3, hole mobilities between 1.6 and 1.9 cm2 V-1 s-1, and resistivities in the range of 0.353-1.555 Ω cm. The ZnO films exhibit (002) (c-plane) orientation as identified by the X-ray diffraction pattern. It is confirmed that N ions were effectively implanted by SIMS results. Raman spectra, polarized Raman spectra, and X-ray photoelectron spectroscopy results reflect that the concentration of oxygen vacancies is reduced, which is attributed to O ion implantation. It is concluded that N and O implantation and dynamic annealing play a critical role in forming p-type single-crystalline ZnO films.

Comparative evaluation of efficacy and soft tissue wound healing using diode laser (810 nm versus conventional scalpel technique for second-stage implant surgery

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Manvir Kaur

2018-01-01

Full Text Available Background: This study was aimed to compare the efficacy and soft tissue wound healing using diode lasers (810 nm versus conventional scalpel approach as uncovering technique during the second-stage surgery in implants. This was a prospective, randomized study which was conducted on 20 subjects in which the implants were already placed using a two-stage technique. Implant sites were examined and the patients were randomly divided into two groups. Materials and Methods: Patients were randomly divided into two groups, i.e., Group A and Group B. In Group A, implants were uncovered as a part of Stage II surgery with conventional scalpel technique, and in Group B, implants were uncovered using 810 nm diode laser. Clinical parameters such as need and amount of local anesthesia, duration of surgery, intraoperative bleeding, pain index, wound healing index (HI, and time for impression taking were recorded at various intervals. Results: Statistical differences for clinical parameters were seen between Group A and Group B showing uncovery of implant with laser more effective, and for time of impression taking, difference was statistically significant showing that impressions were taken early in case of Group A because of better healing which was recorded with help of HI, but the difference in time of healing between Group A and Group B was not statistically significant. Conclusion: The use of a diode laser (810 nm in the second-stage implant surgery can minimize surgical trauma, reduce the amount of anesthesia, improve visibility during surgery due to the absence of bleeding, and eliminate postoperative discomfort.

Delayed Single Stage Perineal Posterior Urethroplasty.

Science.gov (United States)

Ali, Shahzad; Shahnawaz; Shahzad, Iqbal; Baloch, Muhammad Umar

2015-06-01

To determine the delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture/distraction defect. Descriptive case series. Department of Urology, Jinnah Postgraduate Medical Centre, Karachi, from January 2009 to December 2011. Patients were selected for delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture / distraction defect. All were initially suprapubically catheterized followed by definitive surgery after at least 3 months. Thirty male patients were analyzed with a mean follow-up of 10 months, 2 patients were excluded as they developed failure in first 3 months postoperatively. Mean patient's age was 26.25 ± 7.9 years. On follow-up, 7 patients (23.3%) experienced recurrent stricture during first 10 months. Five (16.6%) patients were treated successfully with single direct visual internal urethrotomy. Two patients (6.6%) had more than one direct visual internal urethrotomy and considered failed. Re-do perineal urethroplasty was eventually performed. The overall success rate was 93.3% with permissive criteria allowing single direct visual internal urethrotomy and 76.6% with strict criteria allowing no more procedures postoperatively. Posterior anastomotic urethroplasty offers excellent long-term results to patients with posterior urethral trauma and distraction defect even after multiple prior procedures.

The patient general satisfaction of mandibular single-implant overdentures and conventional complete dentures: Study protocol for a randomized crossover trial.

Science.gov (United States)

Kanazawa, Manabu; Tanoue, Mariko; Miyayasu, Anna; Takeshita, Shin; Sato, Daisuke; Asami, Mari; Lam, Thuy Vo; Thu, Khaing Myat; Oda, Ken; Komagamine, Yuriko; Minakuchi, Shunsuke; Feine, Jocelyne

2018-05-01

Mandibular overdentures retained by a single implant placed in the midline of edentulous mandible have been reported to be more comfortable and function better than complete dentures. Although single-implant overdentures are still more costly than conventional complete dentures, there are a few studies which investigated whether mandibular single-implant overdentures are superior to complete dentures when patient general satisfaction is compared. The aim of this study is to assess patient general satisfaction with mandibular single-implant overdentures and complete dentures. This study is a randomized crossover trial to compare mandibular single-implant overdentures and complete dentures in edentulous individuals. Participant recruitment is ongoing at the time of this submission. Twenty-two participants will be recruited. New mandibular complete dentures will be fabricated. A single implant will be placed in the midline of the edentulous mandible. The mucosal surface of the complete denture around the implant will be relieved for 3 months. The participants will then be randomly allocated into 2 groups according to the order of the interventions; group 1 will receive single-implant overdentures first and will wear them for 2 months, followed by complete dentures for 2 months. Group 2 will receive the same treatments in a reverse order. After experiencing the 2 interventions, the participants will choose one of the mandibular prostheses, and yearly follow-up visits are planned for 5 years. The primary outcome of this trial is patient ratings of general satisfaction on 100 mm visual analog scales. Assessments of the prostheses and oral health-related quality of life will also be recorded as patient-reported outcomes. The secondary outcomes are cost and time for treatment. Masticatory efficiency and cognitive capacity will also be recorded. Furthermore, qualitative research will be performed to investigate the factors associated with success of these mandibular

Risk of pacemaker or implantable cardioverter defibrillator after radiotherapy for early-stage breast cancer in Denmark, 1982-2005

DEFF Research Database (Denmark)

Rehammar, Jens Christian; Johansen, Jens Brock; Jensen, Maj-Britt

2017-01-01

BACKGROUND AND PURPOSE: To examine the risk of cardiac conduction abnormalities or severe ventricular arrhythmias requiring implantation of a cardiac implantable electronic device (CIED), either a pacemaker or an implantable cardioverter-defibrillator, subsequent to breast cancer (BC) radiotherapy...... (RT). MATERIAL AND METHODS: All women treated for early-stage BC in Denmark from 1982 to 2005 were identified from the Danish Breast Cancer Cooperative Group. By record linkage to the Danish Pacemaker and ICD Registry information was retrieved on CIED implants subsequent to RT. Standardized incidence...... ratios (SIR) of CIED implantation were estimated for women receiving RT and compared to women not receiving RT for BC. Uni- and multivariate Poisson regression models were used to estimate incidence rate ratios (IRR) among irradiated women compared to non-irradiated. RESULTS: Of 44,423 BC patients, 179...

Impact of dental implant insertion method on the peri-implant bone tissue: Experimental study

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Stamatović Novak

2013-01-01

Full Text Available Background/Aim. The function of dental implants depends on their stability in bone tissue over extended period of time, i.e. on osseointegration. The process through which osseointegration is achieved depends on several factors, surgical insertion method being one of them. The aim of this study was to histopathologically compare the impact of the surgical method of implant insertion on the peri-implant bone tissue. Methods. The experiment was performed on 9 dogs. Eight weeks following the extraction of lower premolars implants were inserted using the one-stage method on the right mandibular side and two-stage method on the left side. Three months after implantation the animals were sacrificed. Three distinct regions of bone tissue were histopathologically analyzed, the results were scored and compared. Results. In the specimens of one-stage implants increased amount of collagen fibers was found in 5 specimens where tissue necrosis was also observed. Only moderate osteoblastic activity was found in 3 sections. The analysis of bone-to-implant contact region revealed statistically significantly better results regarding the amount of collagen tissue fibers for the implants inserted in the two-stage method (Wa = 59 105, α = 0.05. No necrosis and osteoblastic activity were observed. Conclusion. Better results were achieved by the two-stage method in bone-to-implant contact region regarding the amount of collagen tissue, while the results were identical regarding the osteoblastic activity and bone tissue necrosis. There was no difference between the methods in the bone-implant interface region. In the bone tissue adjacent to the implant the results were identical regarding the amount of collagen tissue, osteoblastic reaction and bone tissue necrosis, while better results were achieved by the two-stage method regarding the number of osteocytes.

Anterior single implants with different neck designs : 5 Year results of a randomized clinical trial

NARCIS (Netherlands)

den Hartog, Laurens; Meijer, Henny J A; Vissink, Arjan; Raghoebar, Gerry M

BACKGROUND: The design of the implant neck might be significant for preservation of marginal bone. PURPOSE: To compare the 5-year radiographic and clinical outcome of single anterior implants provided with a smooth neck, a rough neck or a scalloped rough neck. MATERIALS AND METHODS: 93 Patients with

Characterization of junctions produced by medium-energy ion implantation in silicon

International Nuclear Information System (INIS)

Monfret, A.

1970-01-01

Characteristics of diodes made by implanting 20 keV boron and phosphorus ions into silicon are reviewed. Special features of theses diodes are presented, and correlation with technology is studied. This paper includes three parts: - in the first part, the theory of range distribution is considered for both amorphous and single-crystal targets, - In the second part, a brief description of the experimental conditions is given. - In the third part, the experimental results are presented. The results lead to a schematic model of the component. They also show the influence of cleaning and annealing treatments from which optimized process of fabrication can be determined. In this study, the influence of a two stage annealing process is shown. For phosphorus and boron implants, the first stage is performed at 150 deg. C while the second stage is 450 deg. C for phosphorus and 550 deg. C for boron implants. The implanted diodes are found to exhibit good electrical characteristics. Comparisons with standard diffused diodes are quite favourable. (author) [fr

P-type single-crystalline ZnO films obtained by (Na,N) dual implantation through dynamic annealing process

Science.gov (United States)

Zhang, Zhiyuan; Huang, Jingyun; Chen, Shanshan; Pan, Xinhua; Chen, Lingxiang; Ye, Zhizhen

2018-02-01

Single-crystalline ZnO films were grown by plasma-assisted molecular beam epitaxy technique on c-plane sapphire substrates. The films have been implanted with fixed fluence of 130 keV Na and 90 keV N ions at 460 °C. It is observed that dually-implanted single crystalline ZnO films exhibit p-type characteristics with hole concentration in the range of 1.24 × 1016-1.34 × 1017 cm-3, hole mobilities between 0.65 and 8.37 cm2 V-1 s-1, and resistivities in the range of 53.3-80.7 Ω cm by Hall-effect measurements. There are no other secondary phase appearing, with (0 0 2) (c-plane) orientation after ion implantation as identified by the X-ray diffraction pattern. It is obtained that Na and N ions were successfully implanted and activated as acceptors measured by XPS and SIMS results. Also compared to other similar studies, lower amount of Na and N ions make p-type characteristics excellent as others deposited by traditional techniques. It is concluded that Na and N ion implantation and dynamic annealing are essential in forming p-type single-crystalline ZnO films.

Thermodynamic analysis of single-stage and multi-stage adsorption refrigeration cycles with activated carbon–ammonia working pair

International Nuclear Information System (INIS)

Xu, S.Z.; Wang, L.W.; Wang, R.Z.

2016-01-01

Highlights: • Activated carbon–ammonia multi-stage adsorption refrigerator was analyzed. • COP, exergetic efficiency and entropy production of cycles were calculated. • Single-stage cycle usually has the advantages of simple structure and high COP. • Multi-stage cycles adapt to critical conditions better than single-stage cycle. • Boundary conditions for choosing optimal cycle were summarized as tables. - Abstract: Activated carbon–ammonia multi-stage adsorption refrigeration cycle was analyzed in this article, which realized deep-freezing for evaporating temperature under −18 °C with heating source temperature much lower than 100 °C. Cycle mathematical models for single, two and three-stage cycles were established on the basis of thorough thermodynamic analysis. According to simulation results of thermodynamic evaluation indicators such as COP (coefficient of performance), exergetic efficiency and cycle entropy production, multi-stage cycle adapts to high condensing temperature, low evaporating temperature and low heating source temperature well. Proposed cycle with selected working pair can theoretically work under very severe conditions, such as −25 °C evaporating temperature, 40 °C condensing temperature, and 70 °C heating source temperature, but under these working conditions it has the drawback of low cycle adsorption quantity. It was found that both COP and exergetic efficiency are of great reference value in the choice of cycle, whereas entropy production is not so useful for cycle stage selection. Finally, the application boundary conditions of single-stage, two-stage, and three-stage cycles were summarized as tables according to the simulation results, which provides reference for choosing optimal cycle under different conditions.

Room-temperature ferromagnetism observed in C-/N-/O-implanted MgO single crystals

Science.gov (United States)

Li, Qiang; Ye, Bonian; Hao, Yingping; Liu, Jiandang; Zhang, Jie; Zhang, Lijuan; Kong, Wei; Weng, Huimin; Ye, Bangjiao

2013-01-01

MgO single crystals were implanted with 70 keV C/N/O ions at room temperature with respective doses of 2 × 1016 and 2 × 1017 ions/cm2. All samples with high-dose implantation showed room temperature hysteresis in magnetization loops. Magnetization and slow positron annihilation measurements confirmed that room temperature ferromagnetism in O-implanted samples was attributed to the presence of Mg vacancies. Furthermore, the introduction of C or N played more effective role in ferromagnetic performance than Mg vacancies. Moreover, the magnetic moment possibly occurred from the localized wave function of unpaired electrons and the exchange interaction formed a long-range magnetic order.

One stage rescue procedure after capsular contracture of breast implants with autologous fat grafts collected by water assisted liposuction (“BEAULI Method”

Directory of Open Access Journals (Sweden)

Ueberreiter, Klaus

2013-01-01

Full Text Available With increasing number of patients with silicone implants for breast augmentation or reconstruction we are confronted with more and more cases of capsular contracture. Not every case is resolved by resection of the capsule and exchange of implants. Many patients rather bear the consequences of severe fibrosis than to have their implants removed. The one stage procedure of implant removal and lipofilling proved to be highly efficient with good to excellent results and high patient satisfaction. Between January 2008 and October 2012 a total of 64 patients (124 breasts with capsular fibrosis Baker III to IV were treated with autologous fat grafts collected with the body-jet by water-assisted liposuction (“BEAULI Method”. Magnetic resonance imaging (MRI of the breasts was performed in 5 patients preoperatively and 6 month postoperatively, a clinical examination and photo documentation of all patients was done on day 1 and after 4 weeks, 12 weeks and 6 months postoperatively. The procedure included implant removal and lipofilling of the subcutaneous and intramuscular space in a single procedure by means of the BEAULI Method. The average gross amount of grafted fat was 260 ml. The average drainage time was one day. The shape of the breast changed to a more natural and ptotic form. Negative side effects like oily cysts or infections were not observed. The time of the overall procedure including liposuction was 70±15 min. Reoccurring capsular contracture is one of the hazards in plastic surgery. Until now the treatment of choice after more than two failed implant changes combined with resection of the capsule is usually the final removal of implants with or without possible additional autologous tissue transfer (microvascular flaps. We could add a relatively simple and efficient procedure to resolve and improve those cases by autologous fat transfer using water-assisted liposuction and the BEAULI Method.

Cochlear Implantation and Single-sided Deafness: A Systematic Review of the Literature

Directory of Open Access Journals (Sweden)

Cabral Junior, Francisco

2015-07-01

Full Text Available Introduction Current data show that binaural hearing is superior to unilateral hearing, specifically in the understanding of speech in noisy environments. Furthermore, unilateral hearing reduce onés ability to localize sound. Objectives This study provides a systematic review of recent studies to evaluate the outcomes of cochlear implantation in patients with single-sided deafness (SSD with regards to speech discrimination, sound localization and tinnitus suppression. Data Synthesis We performed a search in the PubMed, Cochrane Library and Lilacs databases to assess studies related to cochlear implantation in patients with unilateral deafness. After critical appraisal, eleven studies were selected for data extraction and analysis of demographic, study design and outcome data. Conclusion Although some studies have shown encouraging results on cochlear implantation and SSD, all fail to provide a high level of evidence. Larger studies are necessary to define the tangible benefits of cochlear implantation in patients with SSD.

Paramagnetism and antiferromagnetic interactions in single-phase Fe-implanted ZnO

CERN Document Server

Pereira, Lino Miguel da Costa; Correia, João Guilherme; Van Bael, M J; Temst, Kristiaan; Vantomme, André; Araújo, João Pedro

2013-01-01

As the intrinsic origin of the high temperature ferromagnetism often observed in wide-gap dilute magnetic semiconductors becomes increasingly debated, there is a growing need for comprehensive studies on the single-phase region of the phase diagram of these materials. Here we report on the magnetic and structural properties of Fe-doped ZnO prepared by ion implantation of ZnO single crystals. A detailed structural characterization shows that the Fe impurities substitute for Zn in ZnO in a wurtzite Zn$_{1−x}$Fe$_{x}$O phase which is coherent with the ZnO host. In addition, the density of beam-induced defects is progressively decreased by thermal annealing up to 900$^{\\circ}$C, from highly disordered after implantation to highly crystalline upon subsequent annealing. Based on a detailed analysis of the magnetometry data, we demonstrate that isolated Fe impurities occupying Zn substitutional sites behave as localized paramagnetic moments down to 2$^{\\circ}$K, irrespective of the Fe concentration and the density...

Delayed Single Stage Perineal Posterior Urethroplasty

International Nuclear Information System (INIS)

Ali, S.; Shahnawaz; Shahzad, I.; Baloch, M. U.

2015-01-01

Objective: To determine the delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture/distraction defect. Study Design: Descriptive case series. Place and Duration of Study: Department of Urology, Jinnah Postgraduate Medical Centre, Karachi, from January 2009 to December 2011. Methodology: Patients were selected for delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture / distraction defect. All were initially suprapubically catheterized followed by definitive surgery after at least 3 months. Results: Thirty male patients were analyzed with a mean follow-up of 10 months, 2 patients were excluded as they developed failure in first 3 months postoperatively. Mean patients age was 26.25 ± 7.9 years. On follow-up, 7 patients (23.3 percentage) experienced recurrent stricture during first 10 months. Five (16.6 percentage) patients were treated successfully with single direct visual internal urethrotomy. Two patients (6.6 percentage) had more than one direct visual internal urethrotomy and considered failed. Re-do perineal urethroplasty was eventually performed. The overall success rate was 93.3 percentage with permissive criteria allowing single direct visual internal urethrotomy and 76.6% with strict criteria allowing no more procedures postoperatively. Conclusion: Posterior anastomotic urethroplasty offers excellent long-term results to patients with posterior urethral trauma and distraction defect even after multiple prior procedures. (author)

Single conversion stage amplifier - SICAM

Energy Technology Data Exchange (ETDEWEB)

Ljusev, P.

2005-12-15

This Ph.D. thesis presents a thorough analysis of the so called SICAM - SIngle Converter stage AMplifier approach to building direct energy conversion audio power amplifiers. The mainstream approach for building isolated audio power amplifiers today consists of isolated DC power supply and Class D amplifier, which essentially represents a two stage solution, where each of the components can be viewed as separate and independent part. The proposed SICAM solution strives for direct energy conversion from the mains to the audio output, by dedicating the operation of the components one to another and integrating their functions, so that the final audio power amplifier represents a single-stage topology with higher efficiency, lower volume, less board space, lower component count and subsequently lower cost. The SICAM approach is both applicable to non-isolated and isolated audio power amplifiers, but the problems encountered in these two cases are different. Non-isolated SICAM solutions are intended for both AC mains-connected and battery-powered devices. In non-isolated mains-connected SICAMs the main idea is to simplify the power supply or even provide integrated power factor correction (PFC) functions, while still maintaining low component stress and good audio performance by generally decreasing the input voltage level to the Class D audio power amplifier. On the other hand, non-isolated battery-powered SICAMs have to cope with the ever changing battery voltage and provide output voltage levels which are both lower and higher than the battery voltage, while still being simple and single-stage energy conversion solutions. In isolated SICAMs the isolation transformer adjusts the voltage level on the secondary side to the desired level, so the main challenges here are decreasing the size of the magnetic core and reducing the number and size of bulky reactive components as much as possible. The main focus of this thesis is directed towards the isolated SICAMs and

Study of percutaneous 125I seeds implantation guided by CT in elderly patients of stage I peripheral non-small cell lung cancer

International Nuclear Information System (INIS)

Ke Mingyao; Yong Yazhi; Luo Bingqing; Wu Xuemei; Chen Lingling; Xie Hongqi

2011-01-01

Objective: To evaluate the efficacy, feasibility and safety of CT guided percutaneous 125 I seeds implantation in elderly patients of stage I peripheral non-small cell lung cancer (NSCLC). Methods: Clinical data of 16 elderly peripheral stage I NSCLC patients (10 squamous carcinoma and 6 adenocarcinoma; 13 stage I A and 3 stage I B ) who received radioactive 125 I seeds implantation because of refusal or being unsuited to operation or external radiotherapy were retrospectively analyzed. Prescribed dose was 140 - 160 Gy. Under CT guidance, 125 I seeds were implanted percutaneously into tumors for interstitial radiotherapy according to treatment plan system. Results: Mean number of 125 I seeds each patient received was 21.1. 12 complete response (CR) and 4 partial response (PR) were achieved. Total response rate (CR + PR) was 100%. 100% patients completed 10 to 56 months of follow-up, 15, 13, 8 and 6 patients completed 1-, 2-, 3-and 4-years' follow-up, respectively. The median local progression free time was 14 months. The 1-, 2-, 3-and 4-year overall survival rate were 60%, 54%, 50% and 33%, respectively (median : 14 months). 7 cases died of non-tumor disease and 5 died of metastasis. No severe complications were observed. Conclusions: CT guided 125 I seeds implantation is a safe, reliable and effective radical treatment method for elderly stage I peripheral NSCLC patients, who refuse to or are unsuitable to operation or external radiotherapy. (authors)

Esthetic outcome and alterations of soft tissue around single implant crowns: a 2-year prospective study.

Science.gov (United States)

Gu, Ying-Xin; Shi, Jun-Yu; Zhuang, Long-Fei; Qiao, Shi-Chong; Xu, You-You; Lai, Hong-Chang

2015-08-01

The aim of this prospective study was to assess the esthetic outcome and alterations of peri-implant soft tissue using tissue-level implants. Furthermore, the influencing factors, including grafting and gingival biotype, of esthetic outcome of peri-implant soft tissue were also evaluated. Of 38 patients with single missing anterior tooth in maxilla were treated with a Straumann (®) Standard Plus SLA implant. Bone augmentation was performed in 24 patients. Follow-up was conducted at 12 and 24 months after definitive crowns placement. Esthetic outcome using the pink esthetic score/white esthetic score (PES/WES) and clinical parameters were evaluated. The mean PES/WES value at baseline, 1-year, and 2-year examination was 13.79, 14.87, and 14.96. Significant improvement was found between baseline and 1-year examination (P esthetic area. Favorable short-term esthetic outcome and stability of soft tissue around single implant crowns can be expected in patients with or without graft. However, graft procedures might have an unfavorable effect on the esthetic outcome. Gingival biotype can be considered as prognostic factor for esthetic outcome. RCTs with long-term follow-up are needed to provide evidence for the long-term stability of peri-implant soft tissue using tissue-level implant systems. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

YouTube and the single-rod contraceptive implant: a content analysis.

Science.gov (United States)

Paul, Jennifer; Boraas, Christy M; Duvet, Mildred; Chang, Judy C

2017-07-01

Since the internet has become an important source of contraceptive information with YouTube.com as the second most visited site, we analysed contraceptive implant YouTube videos for content and clinical accuracy. Using the terms 'contraceptive implant', 'Nexplanon' and 'Implanon', the top 20 results on YouTube by relevance and view count were identified. After excluding duplicates, single-rod implant videos in English were included. Videos were classified as providing a professional or patient perspective. Views, duration and comments were noted. Videos were rated for reliability, global quality scale and whether they were positive or negative about the implant. Inter-rater agreement was measured. A total of 120 videos were retrieved; 52 were eligible for review. Less than 23% were professional videos; the majority reported patient experience (46% testimonials, 27% real-time procedure videos, 4% other). Patient videos had been posted a significantly longer duration of time than professional videos (364 vs 188 days, p =0.02), were less reliable ( p ≤0.0001) and were of lower global quality ( p YouTube pertaining to contraceptive implants is accurate, is presented from the patient's perspective, and promotes the method's use. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Assessment of implant stability during various stages of healing placed immediately following extraction in an overdenture situation

OpenAIRE

Ashwin Thomas Koshy; T Aby Mathew; Nicholas Mathew; Angel Mary Joseph

2017-01-01

To assess the implant stability during different stages of healing in an immediate loaded implant soon after extraction. A 73-year-old female came with a chief complaint of bad smell and irritation in her lower front gum region. On examination, she was found to be completely edentulous in the maxillary arch and partially edentulous in the mandibular arch with only the canines present bilaterally. The posterior mandibular ridge was severely resorbed and hence could not be treated with a conven...

Implanted strontium titanate single crystals for energy storage applications

Energy Technology Data Exchange (ETDEWEB)

Stoeber, Max; Cherkouk, Charaf; Walter, Juliane; Strohmeyer, Ralph; Leisegang, Tilmann; Meyer, Dirk Carl [TU Bergakademie, Freiberg (Germany); Schelter, Matthias; Zosel, Jens [Kurt Schwabe Institute, Meinsberg (Germany); Prucnal, Slawomir [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (Germany)

2016-07-01

A rapid increase of the demand on efficient energy storage solutions requires new approaches beyond the Li-ion technology. In particular, metal-air batteries as well as solid-state fuel cells offer a great potential for high-energy-density storage devices. Since the efficiency of such devices is significantly limited by the activation of both the oxygen reduction reaction (ORR) and the ionic and electronic conductivities, an adequate porosity as well as a controlled doping are required. The ion implantation is a key technology to achieve this goal. In this work, p- and n-doped strontium titanate (SrTiO{sub 3}) single crystals were used as oxidic materials. The oxygen exchange kinetics as well as the structural changes of the SrTiO{sub 3} crystal surface induced by the ion implantation were investigated. On one hand, the depth profile of dopant concentration and dopant valence state were determined using sputtered X-ray photoelectron spectroscopy (XPS). On the other hand, the overall oxygen exchange kinetic of the implanted SrTiO{sub 3} crystal was quantitatively described by means of coulometric titration using Zirox system (ZIROX GmbH, Germany). Furthermore, the surface morphology of the samples was investigated using atomic force microscopy (AFM).

Comparison of Reconstructive Outcomes in Breast Cancer Patients With Preexisting Subpectoral Implants: Implant-Sparing Mastectomy With Delayed Implant Exchange Versus Immediate Tissue Expander Reconstruction.

Science.gov (United States)

Parabkaharan, Sangeetha; Melody, Megan; Trotta, Rose; Lleshi, Amina; Sun, Weihong; Smith, Paul D; Khakpour, Nazanin; Dayicioglu, Deniz

2016-06-01

Women who have undergone prior augmentation mammoplasty represent a unique subset of breast cancer patients with several options available for breast reconstruction. We performed a single institution review of surgical outcomes of breast reconstruction performed in patients with breast cancer with prior history of subpectoral breast augmentation. Institutional review board-approved retrospective review was conducted among patients with previously mentioned criteria treated at our institution between 2000 and 2014. Reconstructions were grouped into 2 categories as follows: (1) removal of preexisting subpectoral implant during mastectomy with immediate tissue expander placement and (2) implant-sparing mastectomy followed by delayed exchange to a larger implant. We reviewed demographics, tumor features, and reconstruction outcomes of these groups. Fifty-three patients had preexisting subpectoral implants. Of the 63 breast reconstructions performed, 18 (28.6%) had immediate tissue expander placed and 45 (71.4%) had implant-sparing mastectomy followed by delayed implant exchange. The groups were comparable based on age, body mass index, cancer type, tumor grade, TNM stage at presentation, and hormonal receptor status. No significant difference was noted between tumor margins or subsequent recurrence, mastectomy specimen weight, removed implant volume, volume of implant placed during reconstruction, or time from mastectomy to final implant placement. Rates of complications were significantly higher in the tissue expander group compared to the implant-sparing mastectomy group 7 (38.9%) versus 4 (8.9%) (P = 0.005). Implant-sparing mastectomy with delayed implant exchange in patients with preexisting subpectoral implants is safe and has fewer complications compared to tissue expander placement. There was no difference noted in the final volume of implant placed, time interval for final implant placement, or tumor margins.

N and Si Implantation Effect on Structural and Electrical Properties of Bridgman grown GaSe Single Crystal

International Nuclear Information System (INIS)

Karabulut, O.

2004-01-01

N and Si implantation to GaSe single crystals were carried out parallel to c-axis with ion beam of about 10 1 6 ions/cm 2 dose having energy values 30, 60 and 100 keV. Ion implantation modifications on Bridgman grown GaSe single crystals have been investigated by means of XRD, electrical conductivity, absorption and photoconductivity measurements. XRD measurements revealed that annealing results in a complete recovery of the crystalline nature that was moderately reduced upon implantation. It was observed that both N- and Siimplantation followed by annealing process decreased the resistivity values from 10 7 to 10 3 .-cm. The analysis of temperature dependent conductivity showed that at high temperature region above 200 K, the transport mechanism is dominated by thermal excitation in the doped and undoped GaSe samples. At lower temperatures, the conduction of carriers is dominated by variable range hopping mechanism in the implanted samples. Absorption and spectral photoconductivity measurements showed that the band edge is shifted in the implanted sample. All these modifications were attributed to the structural modifications and continuous shallow trap levels introduced upon implantation and annealing

[TRENDS OF PERMANENT PACEMAKER IMPLANTATION IN A SINGLE CENTER OVER A 20-YEAR PERIOD].

Science.gov (United States)

Antonelli, Dante; Ilan, Limor Bushar; Freedberg, Nahum A; Feldman, Alexander; Turgeman, Yoav

2015-05-01

To review the changes in permanent pacemaker implantation indications, pacing modes and patients' demographics over a 20-year period. We retrospectively retrieved data on patients who underwent first implantation of the pacemaker between 1-1-1991 and 31-12-2010. One thousand and nine (1,009) patients underwent a first pacemaker implantation during that period; 535 were men (53%), their mean age was 74.6±19.5 years; the highest rate of implanted pacemaker was in patients ranging in age from 70-79 years, however there was an increasing number of patients aged over 80 years. The median survival time after initial pacemaker implantation was 8 years. Syncope was the most common symptom (62.5%) and atrioventricular block was the most common electrocardiographic indication (56.4%) leading to pacemaker implantation. There was increased utilization of dual chamber and rate responsive pacemakers over the years. There was no difference regarding mode selection between genders. Pacemaker implantation rates have increased over a 20-year period. Dual chamber replaced most of the single ventricular chamber pacemaker and rate responsive pacemakers became the norm. The data of a small volume center are similar to those reported in pacemaker surveys of high volume pacemaker implantation centers. They confirm adherence to the published guidelines for pacing.

Immediate occlusal loading of single lower molars using Brånemark System® Wide Platform TiUnite™ implants: a 5-year follow-up report of a prospective clinical multicenter study.

Science.gov (United States)

Calandriello, Roberto; Tomatis, Massimiliano

2011-12-01

Although not essential, molars hold their importance in terms of functional jaw stability, antagonist opposition, and support of facial height. Therefore, implant therapy is an attractive concept in molar areas. However, especially in the posterior mandible, the conventional two-stage surgical approach to implant therapy was reported to cause higher bone loss and/or higher implant failures with machined implants because of the peculiar anatomic and physiologic conditions of this area. As the TiUnite™ (Nobel Biocare AB, Göteborg, Sweden) surface results in faster bone healing than with machined-surface implants, it was hypothesized that this surface would also improve the performance of wide implants in posterior mandibles. Based on these assumptions, a protocol for immediately loaded implants for single molar replacement was developed. This paper aimed to report on the clinical and radiological performance of Brånemark System® TiUnite Wide Platform implants supporting single molars in the lower jaw, loaded immediately and followed for up to 5 years, and to assess if the benefit delivered by oxidized surfaces in the short run is also present after 5 years. The study includes 33 consecutive patients treated between March 2001 and September 2003 and monitored until September 2008 in two private dental offices. A total of 40 Brånemark System TiUnite Wide Platform MK III implants were placed. All implants were provided with provisional crowns in full centric occlusion at the time of surgery. Patients were clinically and radiologically followed up for up to 5 years. Two implant failed so that the cumulative success rate at 5 years was 95.0%. The mean marginal bone remodeling (n = 38) expressed as mesial plus distal value averages was -1.17 mm (SD ± 0.90) at the 5-year time point. Although limited by the number of patients treated in accordance with the protocol described, 5-year results encourage the use of immediately loaded single lower molars supported by Br

Single-stage-to-orbit versus two-stage-two-orbit: A cost perspective

Science.gov (United States)

Hamaker, Joseph W.

1996-03-01

This paper considers the possible life-cycle costs of single-stage-to-orbit (SSTO) and two-stage-to-orbit (TSTO) reusable launch vehicles (RLV's). The analysis parametrically addresses the issue such that the preferred economic choice comes down to the relative complexity of the TSTO compared to the SSTO. The analysis defines the boundary complexity conditions at which the two configurations have equal life-cycle costs, and finally, makes a case for the economic preference of SSTO over TSTO.

Ion implantation effects in single crystal Si investigated by Raman spectroscopy

International Nuclear Information System (INIS)

Harriman, T.A.; Lucca, D.A.; Lee, J.-K.; Klopfstein, M.J.; Herrmann, K.; Nastasi, M.

2009-01-01

A study of the effects of Ar ion implantation on the structural transformation of single crystal Si investigated by confocal Raman spectroscopy is presented. Implantation was performed at 77 K using 150 keV Ar ++ with fluences ranging from 2 x 10 13 to 1 x 10 15 ions/cm 2 . The Raman spectra showed a progression from crystalline to highly disordered structure with increasing fluence. The 520 cm -1 c-Si peak was seen to decrease in intensity, broaden and exhibit spectral shifts indicating an increase in lattice disorder and changes in the residual stress state. In addition, an amorphous Si band first appeared as a shoulder on the 520 cm -1 peak and then shifted to lower wavenumbers as a single broadband peak with a spectral center of 465 cm -1 . Additionally, the emergence of the a-Si TA phonon band and the decrease of the c-Si 2TA and 2TO phonon bands also indicated the same structural transition from crystalline to highly disordered. The Raman results were compared to those obtained by channeling RBS.

Single stage reconstruction of complex anterior urethral strictures

Directory of Open Access Journals (Sweden)

Deepak Dubey

2001-01-01

Full Text Available Purpose: Single stage reconstruction of long, com-plex urethral strictures is technically demanding and may require the use of more than one tissue transfer technique. We describe our experience in the manage-ment of such strictures with a variety of urethroplasty techniques. Materials and Methods: Between 1989 and 1999, 25 men (mean age 38.5 years underwent single stage re-construction of panurethral, multiple segment or focally dense strictures [mean length 11.2 cm (range 8-17 cm]. 8 patients had combined substitution urethroplasty with a circumpenile fasciocutaneous flap and a free graft of bladder/buccal mucosa or tunica vaginalis . flap. In 10 patients a single tissue transfer technique was used. 3 patients underwent an augmented roof/floor strip ure-throplasty with a penile skin flap. 4 patients with multi-ple segment strictures (separate pendulous and bulbar underwent distal onlay flap and proximal anastomotic urethroplasty. Results: The median ,follow-up was 46.5 months (range 6-88 months. The mean postoperative flow rate improved to 22.5 ml/sec. 2 patients developed fistulae requiring repair. Recurrent stricture developed in 5 (20.8% patients, of which 2 were managed with visual internal urethrotomy, 2 with anastomotic urethroplasty and 1 with a two-stage procedure. Pseudodiverticulum and post-void dribbling were seen in 6 (25% patients. Conclusions: Successful outcome of single stage re-construction of long complex strictures can be achieved with a combination of various tissue transfer methods. The urologist who has a thorough knowledge of penile skin and urethral vascular anatomy and a wide array of substitution techniques in his armamentarium can un-dertake approach to such strictures.

Sequential provisional implant prosthodontics therapy.

Science.gov (United States)

Zinner, Ira D; Markovits, Stanley; Jansen, Curtis E; Reid, Patrick E; Schnader, Yale E; Shapiro, Herbert J

2012-01-01

The fabrication and long-term use of first- and second-stage provisional implant prostheses is critical to create a favorable prognosis for function and esthetics of a fixed-implant supported prosthesis. The fixed metal and acrylic resin cemented first-stage prosthesis, as reviewed in Part I, is needed for prevention of adjacent and opposing tooth movement, pressure on the implant site as well as protection to avoid micromovement of the freshly placed implant body. The second-stage prosthesis, reviewed in Part II, should be used following implant uncovering and abutment installation. The patient wears this provisional prosthesis until maturation of the bone and healing of soft tissues. The second-stage provisional prosthesis is also a fail-safe mechanism for possible early implant failures and also can be used with late failures and/or for the necessity to repair the definitive prosthesis. In addition, the screw-retained provisional prosthesis is used if and when an implant requires removal or other implants are to be placed as in a sequential approach. The creation and use of both first- and second-stage provisional prostheses involve a restorative dentist, dental technician, surgeon, and patient to work as a team. If the dentist alone cannot do diagnosis and treatment planning, surgery, and laboratory techniques, he or she needs help by employing the expertise of a surgeon and a laboratory technician. This team approach is essential for optimum results.

Comparative assessment of single-stage and two-stage anaerobic digestion for the treatment of thin stillage.

Science.gov (United States)

Nasr, Noha; Elbeshbishy, Elsayed; Hafez, Hisham; Nakhla, George; El Naggar, M Hesham

2012-05-01

A comparative evaluation of single-stage and two-stage anaerobic digestion processes for biomethane and biohydrogen production using thin stillage was performed to assess the impact of separating the acidogenic and methanogenic stages on anaerobic digestion. Thin stillage, the main by-product from ethanol production, was characterized by high total chemical oxygen demand (TCOD) of 122 g/L and total volatile fatty acids (TVFAs) of 12 g/L. A maximum methane yield of 0.33 L CH(4)/gCOD(added) (STP) was achieved in the two-stage process while a single-stage process achieved a maximum yield of only 0.26 L CH(4)/gCOD(added) (STP). The separation of acidification stage increased the TVFAs to TCOD ratio from 10% in the raw thin stillage to 54% due to the conversion of carbohydrates into hydrogen and VFAs. Comparison of the two processes based on energy outcome revealed that an increase of 18.5% in the total energy yield was achieved using two-stage anaerobic digestion. Copyright © 2012 Elsevier Ltd. All rights reserved.

Temperature and fluence effects in lead implanted cobalt single crystals

International Nuclear Information System (INIS)

Johansen, A.; Sarholt-Kristensen, L.; Johnson, E.; Steenstrup, S.; Chernysh, V.S.

1988-01-01

The channeled sputtering yields of the hcp and fcc phases of cobalt depend on the crystal structure and the radiation induced damage. Earlier irradiations of cobalt with argon ions channeled in the hcp direction give sputtering yields higher than expected in the temperature range 100-350deg C. This effect was attributed to a combination of radiation induced damage and a possible implantation induced hcp --> fcc phase transition. Sputtering yields for cobalt single crystals irradiated with 150 keV Pb + ions along the direction of the hcp phase and the direction of the fcc phase have been measured using the weightloss method. The radiation damage and the amount of lead retained in the implanted surface has been investigated by 'in situ' RBS/channeling analysis. Measured partial sputtering yields of lead ≅ 1 atom/ion indicate preferential sputtering of lead atoms. (orig.)

design, construction and measured performance of a single-stage

African Journals Online (AJOL)

2012-11-03

Nov 3, 2012 ... Abstract. The design philosophy, construction and measured performances of a single stage, single entry centrifugal pump .... the tachometer spindle to be held against a recess in the motor shaft. The constructed centrifugal ...

Immediate loading and customized restoration of a single implant in the maxillary esthetic zone : A clinical report

NARCIS (Netherlands)

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

2009-01-01

The replacement of a single missing anterior tooth with an implant-supported crown Is a demanding therapy. This report describes a treatment in which an anterior maxillary implant was immediately restored with a provisional restoration. During the provisional phase, an optimal emergence profile was

Efficacy of single-stage and two-stage Fowler–Stephens laparoscopic orchidopexy in the treatment of intraabdominal high testis

Directory of Open Access Journals (Sweden)

Chang-Yuan Wang

2017-11-01

Conclusion: In the case of testis with good collateral circulation, single-stage F-S laparoscopic orchidopexy had the same safety and efficacy as the two-stage F-S procedure. Surgical options should be based on comprehensive consideration of intraoperative testicular location, testicular ischemia test, and collateral circumstances surrounding the testes. Under the appropriate conditions, we propose single-stage F-S laparoscopic orchidopexy be preferred. It may be appropriate to avoid unnecessary application of the two-stage procedure that has a higher cost and causes more pain for patients.

Long-term cumulative survival and mechanical complications of single-tooth Ankylos Implants: focus on the abutment neck fractures.

Science.gov (United States)

Shim, Hye Won; Yang, Byoung-Eun

2015-12-01

To evaluate the cumulative survival rate (CSR) and mechanical complications of single-tooth Ankylos® implants. This was a retrospective clinical study that analyzed 450 single Ankylos® implants installed in 275 patients between December 2005 and December 2012. The main outcomes were survival results CSR and implant failure) and mechanical complications (screw loosening, fracture, and cumulative fracture rate [CFR]). The main outcomes were analyzed according to age, sex, implant length or diameter, bone graft, arch, and position. The 8-year CSR was 96.9%. Thirteen (2.9%) implants failed because of early osseointegration failure in 3, marginal bone loss in 6, and abutment fracture in 4. Screw loosening occurred in 10 implants (2.2%), and 10 abutment fractures occurred. All abutment fractures were located in the neck, and concurrent screw fractures were observed. The CSR and rate of screw loosening did not differ significantly according to factors. The CFR was higher in middle-aged patients (5.3% vs 0.0% in younger and older patients); for teeth in a molar position (5.8% vs 0.0% for premolar or 1.1% for anterior position); and for larger-diameter implants (4.5% for 4.5 mm and 6.7% for 5.5 mm diameter vs 0.5% for 3.5 mm diameter) (all Pabutment fractures (2.2%) were observed and some fractures resulted in implant failures. Middle-aged patients, the molar position, and a large implant diameter were associated with a high incidence of abutment fracture.

Lattice location of platinum ions implanted into single crystal zirconia and their annealing behaviour

Energy Technology Data Exchange (ETDEWEB)

Cao, D X [Royal Melbourne Inst. of Tech., VIC (Australia); Sood, D K [Academia Sinica, Shanghai, SH (China). Shanghai Inst. of Nuclear Research; Brown, I G [Lawrence Berkeley Lab., CA (United States)

1994-12-31

Single crystal samples of (100) oriented cubic zirconia stabilised with 9.5 mol % yttria were implanted with platinum ions, using a metal vapour vacuum arc (MEVVA) high current ion implanter, to a nominal dose of 1x10{sup 17} ions/cm{sup 2}. The implanted samples were annealed isothermally in air ambient at 1200 deg C, from 1-24 hours. Rutherford Backscattering Spectrometry and Channeling (RBSC) of 2 MeV He ions are employed to determine depth distributions of ion damage, Pt ions and substitutionality of Pt ions before and after annealing. The damage behaviour, Pt migration and lattice location are discussed in terms of metastable phase formation and solid solubility considerations. 7 refs., 3 figs.

Lattice location of platinum ions implanted into single crystal zirconia and their annealing behaviour

Energy Technology Data Exchange (ETDEWEB)

Cao, D.X. [Royal Melbourne Inst. of Tech., VIC (Australia); Sood, D.K. [Academia Sinica, Shanghai, SH (China). Shanghai Inst. of Nuclear Research; Brown, I.G. [Lawrence Berkeley Lab., CA (United States)

1993-12-31

Single crystal samples of (100) oriented cubic zirconia stabilised with 9.5 mol % yttria were implanted with platinum ions, using a metal vapour vacuum arc (MEVVA) high current ion implanter, to a nominal dose of 1x10{sup 17} ions/cm{sup 2}. The implanted samples were annealed isothermally in air ambient at 1200 deg C, from 1-24 hours. Rutherford Backscattering Spectrometry and Channeling (RBSC) of 2 MeV He ions are employed to determine depth distributions of ion damage, Pt ions and substitutionality of Pt ions before and after annealing. The damage behaviour, Pt migration and lattice location are discussed in terms of metastable phase formation and solid solubility considerations. 7 refs., 3 figs.

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...

Origins of low resistivity in Al ion-implanted ZnO bulk single crystals

Science.gov (United States)

Oga, T.; Izawa, Y.; Kuriyama, K.; Kushida, K.; Kinomura, A.

2011-06-01

The origins of low resistivity in Al ion-implanted ZnO bulk single crystals are studied by combining Rutherford backscattering spectroscopy (RBS), nuclear reaction analysis (NRA), photoluminescence (PL), and Van der Pauw methods. The Al-ion implantation (peak concentration: 2.6 × 1020cm-3) into ZnO is performed using a multiple-step energy. The resistivity decreases from ˜104 Ω cm for un-implanted ZnO to 1.4 × 10-1 Ω cm for as-implanted, and reaches 6.0 × 10-4 Ω cm for samples annealed at 1000 °C. RBS and NRA measurements for as-implanted ZnO suggest the existence of the lattice displacement of Zn (Zni) and O (Oi), respectively. After annealing at 1000 °C, the Zni related defects remain and the Oi related defects disappear. The origin of the low resistivity in the as-implanted sample is attributed to the Zni (˜30 meV [Look et al., Phys. Rev. Lett. 82, 2552 (1999)]). In contrast, the origin of the low resistivity in the sample annealed at 1000 °C is assigned to both of the Zni related defects and the electrically activated Al donor. A new PL emission appears at around 3.32 eV after annealing at 1000 °C, suggesting electrically activated Al donors.

85,000-GPM, single-stage, single-suction LMFBR intermediate centrifugal pump

International Nuclear Information System (INIS)

Fair, C.E.; Cook, M.E.; Huber, K.A.; Rohde, R.

1983-01-01

The mechanical and hydraulic design features of the 85,000-gpm, single-stage, single-suction pump test article, which is designed to circulate liquid-sodium coolant in the intermediate heat-transport system of a Large-Scale Liquid Metal Fast Breeder Reactor (LS-LMFBR), are described. The design and analytical considerations used to satisfy the pump performance and operability requirements are presented. The validation of pump hydraulic performance using a hydraulic scale-model pump is discussed, as is the featute test for the mechanical-shaft seal system

Scaling of ion implanted Si:P single electron devices

International Nuclear Information System (INIS)

Escott, C C; Hudson, F E; Chan, V C; Petersson, K D; Clark, R G; Dzurak, A S

2007-01-01

We present a modelling study on the scaling prospects for phosphorus in silicon (Si:P) single electron devices using readily available commercial and free-to-use software. The devices comprise phosphorus ion implanted, metallically doped (n + ) dots (size range 50-500 nm) with source and drain reservoirs. Modelling results are compared to measurements on fabricated devices and discussed in the context of scaling down to few-electron structures. Given current fabrication constraints, we find that devices with 70-75 donors per dot should be realizable. We comment on methods for further reducing this number

Scaling of ion implanted Si:P single electron devices

Energy Technology Data Exchange (ETDEWEB)

Escott, C C [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Hudson, F E [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Chan, V C [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Petersson, K D [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Clark, R G [Centre for Quantum Computer Technology, School of Physics, UNSW, Sydney, 2052 (Australia); Dzurak, A S [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia)

2007-06-13

We present a modelling study on the scaling prospects for phosphorus in silicon (Si:P) single electron devices using readily available commercial and free-to-use software. The devices comprise phosphorus ion implanted, metallically doped (n{sup +}) dots (size range 50-500 nm) with source and drain reservoirs. Modelling results are compared to measurements on fabricated devices and discussed in the context of scaling down to few-electron structures. Given current fabrication constraints, we find that devices with 70-75 donors per dot should be realizable. We comment on methods for further reducing this number.

Methodology of theory of stage-by-stage long-term preparation of sportsmen in single combats

Directory of Open Access Journals (Sweden)

Arziutov G.

2010-04-01

Full Text Available Results over of researches are brought on methodology of theory of stage-by-stage preparation of sportsmen in single combats. The structuralness of theory lies in possibility simple verifications of its substantive provisions, principles and laws. Development of methodology enables to begin creation of map of trainer on the stages of long-term preparation. Laws, conformities to law, principles and rules, must be collected in a map. A map enables the trainers of reserve sport to use its content during all stages of preparation of sportsman.

X-ray diffraction patterns of single crystals implanted with high-energy light ions

International Nuclear Information System (INIS)

Wieteska, K.

1998-01-01

X-ray diffraction patterns of silicon and gallium arsenide single crystals implanted with high-energy protons and α-particles were studied. A various models of lattice parameter changes were analysed. The agreement between the simulation and experiment proves that the lattice parameter depth-distribution can be assumed to be proportional to vacancy distribution obtained by Monte-Carlo method and from the Biersack-Ziegler theory. Most of the X-ray experiments were performed using synchrotron source of X-ray radiation in particular in the case of back-reflection and transmission section topographic methods. The new method of direct determination of the implanted ion ranges was proposed using synchrotron radiation back-reflection section topography. A number of new interference phenomena was revealed and explained. These interferences are important in the applications of diffraction theory in studying of the real structure of implanted layers. (author)

Cochlear implants in children implanted in Jordan: A parental overview.

Science.gov (United States)

Alkhamra, Rana A

2015-07-01

Exploring the perspective of parents on the cochlear implant process in Jordan. Sixty parents of deaf children were surveyed on the information gathering process prior to cochlear implant surgery, and their implant outcome expectations post-surgery. Whether child or parent characteristics may impact parents' post-surgical expectations was explored. Although parents used a variety of information sources when considering a cochlear implant, the ear, nose and throat doctor comprised their major source of information (60%). Parents received a range of information prior to cochlear implant but agreed (93.3%) on the need for a multidisciplinary team approach. Post-surgically, parents' expected major developments in the areas of spoken language (97%), and auditory skills (100%). Receiving education in mainstream schools (92%) was expected too. Parents perceived the cochlear implant decision as the best decision they can make for their child (98.3%). A significant correlation was found between parents contentment with the cochlear implant decision and expecting developments in the area of reading and writing (r=0.7). Child's age at implantation and age at hearing loss diagnosis significantly affected parents' post-implant outcome expectations (pparents agree on the need for a comprehensive multidisciplinary team approach during the different stages of the cochlear implant process. Parents' education about cochlear implants prior to the surgery can affect their post-surgical outcome expectations. The parental perspective presented in this study can help professionals develop better understanding of parents' needs and expectations and henceforth improve their services and support during the different stages of the cochlear implant process. Copyright © 2015. Published by Elsevier Ireland Ltd.

Lattice site occupation of insoluble impurity atoms in aluminium after implantation and irradiation

International Nuclear Information System (INIS)

Kloska, M.K.

1987-03-01

Several elements, whose atoms are oversized and insoluble in aluminium, were implanted in aluminium single crystals at different temperatures. The substitutional fraction and the lattice site location were determined using the ion-channeling technique. The substitutional fractions obtained by in situ analyses are strongly dependent on the implantation temperature. At implantation and analysis temperatures below the temperature of stage III the substitutional fraction is significant larger than at temperatures above. With increasing heat of solution the substitutional fraction decreases for all implantation temperatures. The nonsubstitutional component consists of impurity atom-vacancy complexes. These complexes are formed in the cooling phase of the cascade. At temperatures above the temperature of stage III additional free mobile vacancies were captured by the impurity atoms. The capture radius is correlated with the heat of solution and the size mismatch energy. The results constitute for the first time an experimental confirmation of molecular dynamics calculations of cascade evolution. (orig./BHO)

Clinical Profile and Early Complications after Single and Dual Chamber Permanent Pacemaker Implantation at Manmohan Cardiothoracic Vascular and Transplant Centre, Kathmandu, Nepal.

Science.gov (United States)

Khanal, J; Poudyal, R R; Devkota, S; Thapa, S; Dhungana, R R

2015-01-01

Permanent pacemaker implantation is a minimally invasive surgical procedure in the management of patients with cardiac problems. However, complications during and after implantation are not uncommon. There is lack of evidences in rate of complications with the selection of pacemakers in Nepal. Therefore, this study was performed to compare the frequency of implantation and complication rate between single chamber and dual chamber pacemaker. The present study is based on all consecutive pacemaker implantations in a single centre between April 2014 and May 2015. A total of 116 patients were categorized into two cohorts according to the type of pacemaker implanted- single chamber or dual chamber. All patients had regular 2-weeks follow-up intervals with standardized documentation of all relevant patient data till 6-week after implantation. Data were presented as means ± standard deviation (SD) for continuous variables and as proportions for categorical variables. Comparison of continuous variables between the groups was made with independent Student's t-test. For discrete variables distribution between groups were compared with Chi-square test. The mean age (±SD) of total population at implant was 64.08 (± 15.09) years. Dual chamber units were implanted in 44 (37.93%) of patients, single chamber in 72 (62.06%). Only 14 women (31.81%) received dual chamber compared with 42 women (58.33%) who received single chamber (Chi-square=18, DF=1, P = 0.0084). Complete atrioventricular block was the commonest (56.03%) indication for permanent pacemaker insertion followed by sick sinus syndrome (33.62%), symptomatic high-grade AV block (11.20%). Hypertension (dual chamber 21.55%, single chamber 40.51%) was the most common comorbidity in both cohorts. Complications occurred in 11 (9.48%) patients. More proportion of complication occurred in single chamber group (9 patients, 12.50%) than in dual chamber (2 patients, 4.54%). Complications occurring in dual chamber group include

Single-session versus staged procedures for elective multivessel percutaneous coronary intervention.

Science.gov (United States)

Toyota, Toshiaki; Morimoto, Takeshi; Shiomi, Hiroki; Yamaji, Kyohei; Ando, Kenji; Ono, Koh; Shizuta, Satoshi; Saito, Naritatsu; Kato, Takao; Kaji, Shuichiro; Furukawa, Yutaka; Nakagawa, Yoshihisa; Kadota, Kazushige; Horie, Minoru; Kimura, Takeshi

2018-06-01

To clarify the effect of single-session multivessel percutaneous coronary intervention (PCI) strategy relative to the staged multivessel strategy on clinical outcomes in patients with stable coronary artery disease (CAD) or non-ST-elevation acute coronary syndrome. In the Coronary REvascularisation Demonstrating Outcome Study in Kyoto PCI/coronary artery bypass grafting registry cohort-2, there were 2018 patients who underwent elective multivessel PCI. Primary outcome measure was composite of all-cause death, myocardial infarction and stroke at 5-year follow-up. Single-session multivessel PCI and staged multivessel PCI were performed in 707 patients (35.0%) and 1311 patients (65.0%), respectively. The cumulative 5-year incidence of and adjusted risk for the primary outcome measure were not significantly different between the single-session and staged groups (26.7% vs 23.0%, p=0.45; HR 0.91, 95% CI 0.72 to 1.16, p=0.47). The 30-day incidence of all-cause death was significantly higher in the single-session group than in the staged group (1.1% vs 0.2%, p=0.009). However, the causes of death in 11 patients who died within 30 days were generally not related to the procedural complications, but related to the serious clinical status before PCI. For the subgroup analyses including age, gender, extent of CAD, severe chronic kidney disease and heart failure, there was no significant interaction between the subgroup factors and the effect of the single-session strategy relative to the staged strategy for the primary outcome measure. The single-session multivessel PCI strategy was associated with at least comparable 5-year clinical outcomes compared with the staged multivessel PCI, although the prevalence of the single-session strategy was low in the present study. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Fatigue resistance of 2 different CAD/CAM glass-ceramic materials used for single-tooth implant crowns.

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Çavuşoğlu, Yeliz; Sahin, Erdal; Gürbüz, Riza; Akça, Kivanç

2011-10-01

To evaluate the fatigue resistance of 2 different CAD/CAM in-office monoceramic materials with single-tooth implant-supported crowns in functional area. A metal experimental model with a dental implant was designed to receive in-office CAD/CAM-generated monoceramic crowns. Laterally positioned axial dynamic loading of 300 N at 2 Hz was applied to implant-supported crowns machined from 2 different glass materials for 100,000 cycle. Failures in terms of fracture, crack formation, and chipping were macroscopically recorded and microscopically evaluated. Four of 10 aluminasilicate glass-ceramic crowns fractured at early loading cycles, the rest completed loading with a visible crack formation. Crack formation was recorded for 2 of 10 leucite glass-ceramic crowns. Others completed test without visible damage but fractured upon removal. Lack in chemical adhesion between titanium abutment and dental cement likely reduces the fatigue resistance of machinable glass-ceramic materials. However, relatively better fractural strength of leucite glass-ceramics could be taken into consideration. Accordingly, progress on developmental changes in filler composition of glass-ceramics may be promising. Machinable glass-ceramics do not possess sufficient fatigue resistance for single-tooth implant crowns in functional area.

The single-tooth implant treatment of congenitally missing maxillary lateral incisors using angled abutments: A clinical report

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Suleyman Hakan Tuna

2009-01-01

Full Text Available The maxillary lateral incisor is the second most common congenitally absent tooth. There are several treatment options for replacing the missing maxillary lateral incisor, including canine substitution, tooth-supported restoration, or single-tooth implant. Dental implants are an appropriate treatment option for replacing missing maxillary lateral incisor teeth in adolescents when their dental and skeletal development is complete. This case report presents the treatment of a patient with congenitally missing maxillary lateral incisors using dental implants with angled abutments.

Esthetics of Flapless Single-Tooth Implants in the Anterior Maxilla Using Guided Surgery: Association of Three-Dimensional Accuracy and Pink Esthetic Score.

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Fürhauser, Rudolf; Mailath-Pokorny, Georg; Haas, Robert; Busenlechner, Dieter; Watzek, Georg; Pommer, Bernhard

2015-10-01

Flapless implant placement using surgical templates may guarantee predictable and esthetic results provided that preplanned implant positions are transfered precisely into surgical reality. The study aims to investigate the effect of three-dimensional accuracy in guided implant surgery on the esthetic outcome of single-tooth implants in the anterior maxilla. Single-tooth implants for delayed replacement of upper incisors were inserted in 27 patients using stereolithographic templates. Superimposition of postoperative cone beam computed tomography (CBCT) scans allowed assessment of positional inaccuracy at the implant shoulder and apex, as well as angular deviation. Objective evaluation of implant esthetics was performed after a mean follow-up of 2.3 years using the Pink Esthetic Score (PES). Mean deviation between planned and actual implant position was 0.84 mm at the implant shoulder and significantly correlated to average PES of 12 (p = .031). Inaccuracy toward the buccal side was most frequent (70%). Deviations  ≥  0.8  mm resulted in significantly worse implant esthetics (median PES: 9.5, interquartile range [IQR]: 8-11) compared with more accurate implant positions (median PES: 13, IQR: 12-13, p = .039). Positional inaccuracy is low in guided implant surgery, but may however significantly compromise implant esthetics in the anterior maxilla. © 2014 Wiley Periodicals, Inc.

“REPRESENTATION, PROJECTION AND COCHLEAR IMPLANT: A SINGLE CASE STUDY”

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Carmela Mento

2014-06-01

Full Text Available From the psychological point of view hearing is an essential sensory modality for the human species, because it contributes to the formation of the first relational connections and emotions. It is important to make a diagnosis early to intervene and limit negative effects.  Deafness is a particular phenomenon (onset, types,  in this paper we undertake a thorough descriptive analysis on all aspects of deafness, in particular the use of a prosthetic device known as cochlear implant.  We have deepened personality variables in a single case with the use of Rorschach Test and Draw-a-person-Test.  We aimed to study, with the clinical interpretation of instruments, which personality variables could be involved in hearing loss condition and Cochlear Implant (CI.  This observational study highlights the psychological dynamics that should be taken into account by operators team, in order to improve the quality of life of these patients and increase their long-term therapeutic outcome.

Influence of surgical and prosthetic techniques on marginal bone loss around titanium implants. Part I: immediate loading in fresh extraction sockets.

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Berberi, Antoine N; Tehini, Georges E; Noujeim, Ziad F; Khairallah, Alexandre A; Abousehlib, Moustafa N; Salameh, Ziad A

2014-10-01

Delayed placement of implant abutments has been associated with peri-implant marginal bone loss; however, long-term results obtained by modifying surgical and prosthetic techniques after implant placement are still lacking. This study aimed to evaluate the marginal bone loss around titanium implants placed in fresh extraction sockets using two loading protocols after a 5-year follow-up period. A total of 36 patients received 40 titanium implants (Astra Tech) intended for single-tooth replacement. Implants were immediately placed into fresh extraction sockets using either a one-stage (immediate loading by placing an interim prosthesis into functional occlusion) or a two-stage prosthetic loading protocol (insertion of abutments after 8 weeks of healing time). Marginal bone levels relative to the implant reference point were evaluated at four time intervals using intraoral radiographs: at time of implant placement, and 1, 3, and 5 years after implant placement. Measurements were obtained from mesial and distal surfaces of each implant (α = 0.05). One-stage immediate implant placement into fresh extraction sockets resulted in a significant reduction in marginal bone loss (p sockets reduced marginal bone loss and did not compromise the success rate of the restorations. © 2014 by the American College of Prosthodontists.

Transition from failing dentition to full-arch fixed implant-supported prosthesis with a staged approach using removable partial dentures: a case series.

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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.

Long-term Stability of Soft Tissue Esthetic Outcomes Following Conventional Single Implant Treatment in the Anterior Maxilla: 10-12 Year Results.

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Rokn, A; Bassir, S H; Rasouli Ghahroudi, A A; Kharazifard, M J; Manesheof, R

2016-01-01

The present study aimed to evaluate the long-term stability of esthetic outcomes of soft tissue around maxillary anterior single-tooth implants after 10-to-12 years of loading. Patients who had been treated for single-tooth implants in the anterior maxilla between February 2000 and July 2002 were invited to participate in the study. All implants had been placed according to delayed implant placement and conventional loading protocols without any connective tissue graft or papilla preservation flaps. Pink Esthetic Score (PES) was rated using standardized clinical photographs to assess the esthetic outcomes of the implant treatment at the time of crown placement and at time of follow-up examination which was at least 10 years after the crown placement. A total of 19 patients were included. The mean score of PES was 11.63 (SD 1.61; range 7-14) at baseline. After 10-to-12 years of function, a mean PES score of 11.05 (SD 2.09; range 6-14) was recorded. No significant differences were found in the esthetic outcomes, categorized based on clinically relevant levels, between the baseline and follow-up session (p>0.05). Within limitation of the present study, it can be concluded that the esthetic outcomes of soft tissue around the maxillary anterior single-tooth implants placed using conventional implant placement technique remained stable in the long-term.

Evaluation of the Cortical Bone Reaction Around of Implants Using a Single-Use Final Drill: A Histologic Study.

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Gehrke, Sergio Alexandre

2015-07-01

This study was designed to compare the cortical bone reaction following traditional osteotomy or the use of a single-use final drill in the osseointegration of implants in the tibia of rabbits. For this study, 48 conical implants, of standard surface type and design and manufactured by the same company, were inserted into the tibiae of 12 rabbits and removed after 30 or 60 days for histologic analysis. Two test groups were prepared according to the drill sequence used for the osteotomy at the preparation sites: in the control group was used a conventional drill sequence with several uses, whereas the test group (tesG) used a single-use final drill. The bone-to-implant contact and qualitative factors of the resulting cortical bone were assessed. Both techniques produced good implant integration. Differences in the linear bone-to-implant contact were observed between the drilling procedures as time elapsed in vivo, with the tesG appearing to have clinical advantages. Both groups exhibited new bone in quantity and in quality; however, the tesG exhibited a higher level of new bone deposition than the control group. Within the limitations of this study, the findings suggest that the use of a single-use final drill leads to better and faster organization of the cortical bone area during the evaluated period and may avoid the possible problems that can be caused by worn drills.

Single-implant overdentures retained by the Novaloc attachment system: study protocol for a mixed-methods randomized cross-over trial.

Science.gov (United States)

de Souza, Raphael F; Bedos, Christophe; Esfandiari, Shahrokh; Makhoul, Nicholas M; Dagdeviren, Didem; Abi Nader, Samer; Jabbar, Areej A; Feine, Jocelyne S

2018-04-23

Overdentures retained by a single implant in the midline have arisen as a minimal implant treatment for edentulous mandibles. The success of this treatment depends on the performance of a single stud attachment that is susceptible to wear-related retention loss. Recently developed biomaterials used in attachments may result in better performance of the overdentures, offering minimal retention loss and greater patient satisfaction. These biomaterials include resistant polymeric matrixes and amorphous diamond-like carbon applied on metallic components. The objective of this explanatory mixed-methods study is to compare Novaloc, a novel attachment system with such characteristics, to a traditional alternative for single implants in the mandible of edentate elderly patients. We will carry out a randomized cross-over clinical trial comparing Novaloc attachments to Locators for single-implant mandibular overdentures in edentate elderly individuals. Participants will be followed for three months with each attachment type; patient-based, clinical, and economic outcomes will be gathered. A sample of 26 participants is estimated to be required to detect clinically relevant differences in terms of the primary outcome (patient ratings of general satisfaction). Participants will choose which attachment they wish to keep, then be interviewed about their experiences and preferences with a single implant prosthesis and with the two attachments. Data from the quantitative and qualitative assessments will be integrated through a mixed-methods explanatory strategy. A last quantitative assessment will take place after 12 months with the preferred attachment; this latter assessment will enable measurement of the attachments' long-term wear and maintenance requirements. Our results will lead to evidence-based recommendations regarding these systems, guiding providers and patients when making decisions on which attachment systems and implant numbers will be most appropriate for

Clinical observation of Artisan iris-clip intraocular lens implantation at stage Ⅰ

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Qing Zhou

2014-09-01

Full Text Available AIM: To observe the clinical efficacy of Artisan iris-clip intraocular lens(IOLimplantation on cataract with a wide range of lens dislocation.METHODS: Twenty-four hospital patients(28 eyesof cataract with lens subluxation by trauma(20 patients, 20 eyesand Marfan's syndrome(4 patients, 8 eyesduring May 2007 to December 2011 were selected. All of them underwent phacoemulsification or an anterior vitrectomy and Artisan iris-clip IOL implantation at stage Ⅰ. Postoperative visual acuity, corneal endothelial cell count, intraocular lens position and postoperative complications were observed. Follow-up time was 6mo.RESULTS:Compared with the preoperative, postoperative best corrected visual acuity improved to varying degrees, visual acuity of 0.1-0.5 was in 20 eyes, 0.5-1.0 in 8 eyes. After followed up 1-6mo, no artificial lens shift, iris inflammation, iris atrophy and corneal decompensation and other complications were observed.CONCLUSION: Cataract surgery with a wide range of lens dislocation is difficult, but as long as surgeons who have a wealth of clinical experience and superb skills, still can carry out phacoemulsification surgery or anterior vitrectomy and Artisan iris-clip IOL implantation and obtain a better outcome.

Irradiation effects and hydrogen behavior in H{sub 2}{sup +} and He{sup +} implanted γ-LiAlO{sub 2} single crystals

Energy Technology Data Exchange (ETDEWEB)

Jiang, Weilin, E-mail: weilin.jiang@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA (United States); Zhang, Jiandong; Kovarik, Libor; Zhu, Zihua [Pacific Northwest National Laboratory, Richland, WA (United States); Price, Lloyd; Gigax, Jonathan; Castanon, Elizabeth; Wang, Xuemei; Shao, Lin [Department of Nuclear Engineering, Texas A& M University, College Station, TX (United States); Senor, David J. [Pacific Northwest National Laboratory, Richland, WA (United States)

2017-02-15

Gamma-phase lithium aluminate (γ-LiAlO{sub 2}) is a breeder material for tritium, a necessary substance for strategic stockpile and fusion power systems. A fundamental study of structural evolution and tritium diffusion in γ-LiAlO{sub 2} under displacive irradiation is needed to fully assess the material performance. This study utilizes ion implantation of protium (surrogate for tritium) and helium in γ-LiAlO{sub 2} single crystals at elevated temperatures to emulate the irradiation effects. The results show that at 573 K there are two distinct disorder saturation stages to 1 dpa without full amorphization; overlapping implantation of H{sub 2}{sup +} and He{sup +} ions suggests possible formation of gas bubbles. For irradiation to 10{sup 21} H{sup +}/m{sup 2} (0.36 dpa at peak) at 773 K, amorphization occurs at surface with H diffusion and dramatic Li loss; the microstructure contains bubbles and cubic LiAl{sub 5}O{sub 8} precipitates with sizes up to 200 nm or larger. In addition, significant H diffusion and release are observed during thermal annealing. - Highlights: • Disorder saturation stages are observed in γ-LiAlO{sub 2} irradiated with H{sub 2}{sup +} ions at 573 K. • Li loss occurs during H{sub 2}{sup +} ion implantation in γ-LiAlO{sub 2} at elevated temperatures (573–773 K). • Both gas bubbles and cubic LiAl{sub 5}O{sub 8} precipitates are formed in γ-LiAlO{sub 2} irradiated with H{sub 2}{sup +} ions at 773 K. • Isochronal annealing at temperatures up to 773 K leads to significant H release.

Comparing a single-stage geocoding method to a multi-stage geocoding method: how much and where do they disagree?

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Rice Kenneth

2007-03-01

Full Text Available Abstract Background Geocoding methods vary among spatial epidemiology studies. Errors in the geocoding process and differential match rates may reduce study validity. We compared two geocoding methods using 8,157 Washington State addresses. The multi-stage geocoding method implemented by the state health department used a sequence of local and national reference files. The single-stage method used a single national reference file. For each address geocoded by both methods, we measured the distance between the locations assigned by each method. Area-level characteristics were collected from census data, and modeled as predictors of the discordance between geocoded address coordinates. Results The multi-stage method had a higher match rate than the single-stage method: 99% versus 95%. Of 7,686 addresses were geocoded by both methods, 96% were geocoded to the same census tract by both methods and 98% were geocoded to locations within 1 km of each other by the two methods. The distance between geocoded coordinates for the same address was higher in sparsely populated and low poverty areas, and counties with local reference files. Conclusion The multi-stage geocoding method had a higher match rate than the single-stage method. An examination of differences in the location assigned to the same address suggested that study results may be most sensitive to the choice of geocoding method in sparsely populated or low-poverty areas.

Use of a single implant to retain mandibular overdenture: A preliminary clinical trial of 13 cases

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Tao Cheng

2012-09-01

Conclusion: Within the limitations of this preliminary prospective clinical study, single-implant-supported mandibular overdentures were a successful alternative treatment option for elderly edentulous patients.

二极管激光在种植二期手术中的应用%The application of diode laser in the secondary-stage implant surgery

Institute of Scientific and Technical Information of China (English)

徐可卿

2014-01-01

目的：评价二极管激光在种植二期手术中的临床效果。方法对84例（207颗）种植体植入后3～6个月，牙龈完全覆盖或部分覆盖种植体的患者在表面麻醉下用二极管激光进行龈盖切除术，暴露并取出覆盖螺丝，安装愈合基台，两周后进行金属烤瓷全冠修复，评价修复后1个月的临床效果。结果术中不出血、创面清晰、手术时间短、术后无疼痛及肿胀、切口愈合快。修复效果良好194颗（93．72％），效果一般9颗（4．35％），效果差4颗（1．93％），成功率为98．07％，所有患者无并发症。结论二极管激光在种植二期手术中具有无痛、精确、舒适、高效、安全和微创的优势。%Objective To evaluate the clinical effects of diode laser in the secondary-stage implant surgery.Methods The 207 im-plants of 84 patients whose gum covered the surface of implant were treated with diode laser irradiation under the superficial anesthesia three to six months after implantation.The cover screws were taken.The healing abutments were placed on the implants.The ceramomet-al crown restoration was performed two weeks later.The outcomes were evaluated one month after restoration.Resuits There was no hemorrhage during operation;the operation time was short;there was no pain or swelling after operation and the cut healed quickly.A-mong the 207 implants,194 implants (93.72%) were at good stage,9 implants (4.35%) were at general stage,and 4 implants (1 .93%)were at poor stage.The implant survival ratio was 98.07%.There were no complications.Conclusions Diode Laser is pain-less,accurate,comfortable,effective,safe and of small harm in the secondary-stage implant surgery.

Single Dexamethasone Intravitreal Implant in the Treatment of Noninfectious Uveitis.

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Frère, Ariane; Caspers, Laure; Makhoul, Dorine; Judice, Lia; Postelmans, Laurence; Janssens, Xavier; Lefebvre, Pierre; Mélot, Christian; Willermain, François

2017-05-01

To investigate the effect of a single intravitreal dexamethasone implant (IVT-DI; Ozurdex; Allergan, Inc.) on visual acuity, macular thickness, and intraocular pressure (IOP) in active noninfectious uveitis. Medical records of patients with noninfectious active uveitis treated by IVT-DIs were retrospectively reviewed. Uveitis etiologies, treatment indications, best corrected visual acuity (BCVA), central retinal thickness measured by ocular coherence tomography, IOP, and systemic, local, and topical treatments were collected. Parameters were analyzed before the injection of the implant, after 1.5 ± 0.8 months and 4.4 ± 0.9 months for the BCVA, after 2 ± 1.3 months and 4.6 ± 1.3 months for the ocular coherence tomography, and after 1.3 ± 0.7 months and 4.4 ± 1 months for the IOP. We included 14 patients (20 eyes, 20 implant injections) with cystoid macular edema (78%), vasculitis (7%), choroiditis (7%), and vasculitis associated with choroiditis (7%). Before the injection, mean visual acuity was 0.4 ± 0.5 logMAR (logarithm of the minimum angle of resolution) that improved to 0.3 ± 0.5 logMAR (P = 0.0002) after 1.5 ± 0.8 months and to 0.3 ± 0.5 logMAR (P = 0.005) after 4.4 ± 0.9 months. A statistically significant decrease of macular thickness was observed both at 2 ± 1.3 months and at 4.6 ± 1.3 months after IVT-DI. Mean IOP was 16 ± 5 mmHg before injections, 18 ± 6 mmHg (P = 0.13) at 1.3 ± 0.7 months, and 15 ± 4 mmHg (P = 0.65) at 4.4 ± 1 months. By Kaplan-Meier analysis, we found that after 3.3 months, 17% of the eyes still present a BCVA amelioration ≥0.3 logMAR. In our patients with active noninfectious uveitis, injection of a first single dexamethasone implant was found to improve visual acuity and decrease macular thickness without significant increase of IOP, although the effect seems limited in time.

An in vitro study to compare the accuracy of the master cast fabricated by four different transfer impression techniques for single-tooth implant replacement.

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Lahori, Manesh; Nagrath, Rahul; Agrawal, Prateek

2014-03-01

Single tooth implant retained crowns have become a recognized technique for the replacement of the missing teeth. With the predictable integration of implants, the emphasis is shifted towards precise prosthesis. Minor movement of the impression coping retained inside the impression material can occur during all the procedures, leading to the three-dimensional spatial inaccuracies in the master casts. Therefore, the present study was undertaken with the purpose to evaluate the accuracy of single-tooth implant impression techniques using four different impression copings, so as to obtain a precise definitive cast for a single-unit implant restoration. A maxillary acrylic resin model with a standard single implant in the first molar region was used to simulate a clinical situation. A total of 60 impressions were made with polyvinylsiloxane impression material, which were divided into four groups of 15 impressions each. Group I used non-modified square impression coping, while in group II, III and IV square impression coping were modified differently. Master casts fabricated for all the groups were analyzed to detect rotational position change of the hexagon on the implant replicas in the master casts in reference to the resin model. The master casts obtained with the roughened and adhesive-coated impression copings showed a lower amount of rotational movement than the masters casts achieved with the non-modified impression copings. Hence, the clinician should use sandblasted and adhesive coated impression copings to achieve a more accurate and precise orientation of the implant replicas in the laboratory master casts in single-tooth implant restorations.

Outcomes with single-coil versus dual-coil implantable cardioverter defibrillators: a meta-analysis.

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Sunderland, Nicholas; Kaura, Amit; Murgatroyd, Francis; Dhillon, Para; Scott, Paul A

2018-03-01

Dual-coil implantable cardioverter defibrillator (ICD) leads have traditionally been used over single-coil leads due to concerns regarding high defibrillation thresholds (DFT) and consequent poor shock efficacy. However, accumulating evidence suggests that this position may be unfounded and that dual-coil leads may also be associated with higher complication rates during lead extraction. This meta-analysis collates data comparing dual- and single-coil ICD leads. Electronic databases were systematically searched for randomized controlled trials (RCT) and non-randomized studies comparing single-coil and dual-coil leads. The mean differences in DFT and summary estimates of the odds-ratio (OR) for first-shock efficacy and the hazard-ratio (HR) for all-cause mortality were calculated using random effects models. Eighteen studies including a total of 138,124 patients were identified. Dual-coil leads were associated with a lower DFT compared to single coil leads (mean difference -0.83J; 95% confidence interval [CI] -1.39--0.27; P = 0.004). There was no difference in the first-shock success rate with dual-coil compared to single-coil leads (OR 0.74; 95%CI 0.45-1.21; P=0.22). There was a significantly lower risk of all-cause mortality associated with single-coil leads (HR 0.91; 95%CI 0.86-0.95; P dual-coil leads. The mortality benefit with single-coil leads most likely represents patient selection bias. Given the increased risk and complexity of extracting dual-coil leads, centres should strongly consider single-coil ICD leads as the lead of choice for routine new left-sided ICD implants. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Removal torque evaluation of three different abutment screws for single implant restorations after mechanical cyclic loading.

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Paepoemsin, T; Reichart, P A; Chaijareenont, P; Strietzel, F P; Khongkhunthian, P

2016-01-01

The aim of this study was to evaluate the removal torque of three different abutment screws and pull out strength of implant-abutment connection for single implant restorations after mechanical cyclic loading. The study was performed in accordance with ISO 14801:2007. Three implant groups (n=15) were used: group A, PW Plus® with flat head screw; group B, PW Plus® with tapered screw; and group C, Conelog® with flat head screw. All groups had the same implant-abutment connection feature: cone with mandatory index. All screws were tightened with manufacturer's recommended torque. Ten specimens in each group underwent cyclic loading (1×106 cycles, 10 Hz, and 250 N). Then, all specimens were un-tightened, measured for the removal torque, and underwent a tensile test. The force that dislodged abutment from implant fixture was recorded. The data were analysed using independent sample t-test, ANOVA and Tukey HSD test. Before cyclic loading, removal torque in groups A, B and C were significantly different (B> A> C, Pabutment from implant fixture increased immensely after cyclic loading.

Investigation of Advanced Propellants to Enable Single Stage to Orbit Launch Vehicles

National Research Council Canada - National Science Library

Mossman, Jason

2006-01-01

Single-Stage-To-Orbit (SSTO) launch vehicles designs offer the promise of reduced complexity and cost compared to multi-stage vehicles, as only one stage need be developed, produced, and maintained...

Clinician assessments and patient perspectives of single-tooth implant restorations in the esthetic zone of the maxilla: A systematic review.

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Arunyanak, Sirikarn P; Pollini, Adrien; Ntounis, Athanasios; Morton, Dean

2017-07-01

Esthetic outcomes associated with implant dentistry are important to both clinicians and patients. However, esthetic satisfaction may vary between the 2 groups. In order to evaluate the current publications relating to this topic, the following focused question was developed, "what are the quantitative and qualitative differences between clinician evaluations and patient perspectives in the assessment of single-tooth implant outcomes in the esthetic zone?" The purpose of this systematic review was to identify differences in esthetic satisfaction between clinicians and patients when evaluating single-tooth implant-supported restorations. An electronic search of the Medline database and Cochrane Central Register of Controlled Trials (2000 to 2014) was performed. The search was supplemented by a manual search of specific journals. A quality assessment of full-text articles was performed according to Cochrane Collaboration's tool and Newcastle-Ottawa scale for risk of bias assessment. Information regarding outcomes was collected and compared. The search term combinations identified 555 titles. Subsequent to further review, 11 publications, including 2 randomized controlled trials, were selected for inclusion. Because of the heterogeneity of the study designs, study interventions, and esthetic assessment methods, no meta-analysis was performed. The clinicians identified a satisfactory outcome in 51% to 100% for peri-implant soft tissue and 62% to 90% for implant restorations. Patients showed a mean range score of 43% to 93% for peri-implant soft tissue and 81% to 96% for implant restorations. The visual analog scale score of the dentists was always lower than that of the patients. The review identified correlations between subjective and objective assessments for the Pink Esthetic Score (PES), the Papilla Index (PI), the Implant Crown Aesthetic Index (ICAI), and the modified (mod-ICAI) indices. Clinicians are more critical of esthetic outcomes than patients. The PES and

One-stage vs two-stage cartilage repair: a current review

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Daniel Meyerkort

2010-10-01

Full Text Available Daniel Meyerkort, David Wood, Ming-Hao ZhengCenter for Orthopaedic Research, School of Surgery and Pathology, University of Western Australia, Perth, AustraliaIntroduction: Articular cartilage has a poor capacity for regeneration if damaged. Various methods have been used to restore the articular surface, improve pain, function, and slow progression to osteoarthritis.Method: A PubMed review was performed on 18 March, 2010. Search terms included “autologous chondrocyte implantation (ACI” and “microfracture” or “mosaicplasty”. The aim of this review was to determine if 1-stage or 2-stage procedures for cartilage repair produced different functional outcomes.Results: The main procedures currently used are ACI and microfracture. Both first-generation ACI and microfracture result in clinical and functional improvement with no significant differences. A significant increase in functional outcome has been observed in second-generation procedures such as Hyalograft C, matrix-induced ACI, and ChondroCelect compared with microfracture. ACI results in a higher percentage of patients with clinical improvement than mosaicplasty; however, these results may take longer to achieve.Conclusion: Clinical and functional improvements have been demonstrated with ACI, microfracture, mosaicplasty, and synthetic cartilage constructs. Heterogeneous products and lack of good-quality randomized-control trials make product comparison difficult. Future developments involve scaffolds, gene therapy, growth factors, and stem cells to create a single-stage procedure that results in hyaline articular cartilage.Keywords: autologous chondrocyte implantation, microfracture, cartilage repair

Numerical Simulation of single-stage axial fan operation under dusty flow conditions

Science.gov (United States)

Minkov, L. L.; Pikushchak, E. V.

2017-11-01

Assessment of the aerodynamic efficiency of the single-stage axial flow fan under dusty flow conditions based on a numerical simulation using the computational package Ansys-Fluent is proposed. The influence of dust volume fraction on the dependences of the air volume flow rate and the pressure drop on the rotational speed of rotor is demonstrated. Matching functions for formulas describing a pressure drop and volume flow rate in dependence on the rotor speed and dust content are obtained by numerical simulation for the single-stage axial fan. It is shown that the aerodynamic efficiency of the single-stage axial flow fan decreases exponentially with increasing volume content of dust in the air.

Promising results after single-stage reconstruction of the nipple and areola complex

DEFF Research Database (Denmark)

Børsen-Koch, Mikkel; Bille, Camilla; Thomsen, Jørn B

2013-01-01

Introduction: Reconstruction of the nipple-areola complex (NAC) traditionally marks the end of breast reconstruction. Several different surgical techniques have been described, but most are staged procedures. This paper describes a simple single-stage approach. Material and Methods: We used...... reconstruction was 43 min. (30-50 min.). Conclusion: This simple single-stage NAC reconstruction seems beneficial for both patient and surgeon as it seems to be associated with faster reconstruction and reduced procedure-related time without compromising the aesthetic outcome or the morbidity associated...

CAD/CAM glass ceramics for single-tooth implant crowns: a finite element analysis.

Science.gov (United States)

Akça, Kvanç; Cavusoglu, Yeliz; Sagirkaya, Elcin; Aybar, Buket; Cehreli, Murat Cavit

2013-12-01

To evaluate the load distribution of CAD/CAM mono-ceramic crowns supported with single-tooth implants in functional area. A 3-dimensional numerical model of a soft tissue-level implant was constructed with cement-retained abutment to support glass ceramic machinable crown. Implant-abutment complex and the retained crown were embedded in a Ø 1.5 × 1.5 cm geometric matrix for evaluation of mechanical behavior of mono-ceramic CAD/CAM aluminosilicate and leucite glass crown materials. Laterally positioned axial load of 300 N was applied on the crowns. Resulting principal stresses in the mono-ceramic crowns were evaluated in relation to different glass ceramic materials. The highest compressive stresses were observed at the cervical region of the buccal aspect of the crowns and were 89.98 and 89.99 MPa, for aluminosilicate and leucite glass ceramics, respectively. The highest tensile stresses were observed at the collar of the lingual part of the crowns and were 24.54 and 25.39 MPa, respectively. Stresses induced upon 300 N static loading of CAD/CAM aluminosalicate and leucite glass ceramics are below the compressive strength of the materials. Impact loads may actuate the progress to end failure of mono-ceramic crowns supported by metallic implant abutments.

Single-stage Modified Duhamel procedure for Hirschsprung′s disease : Our experience

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Paras R Kothari

2012-01-01

Full Text Available Introduction: Primary single-stage pull-through for Hirschsprung′s disease (HD has been reported to give comparable surgical outcomes to staged operations with less morbidity. Herein, we present our experience with single-stage Modified Duhamel procedure for management of HD. Patients and Methods: This was a review of 48 cases of HD who underwent single-stage Modified Duhamel procedure without a protective colostomy. Results: The age at surgery ranged from 6 months to 10 years (median - 9 months, mean - 2.3 years. The average weight of the child was 7.2 kg (range, 4.9-22 kg. 38 (79.2% patients had classical rectosigmoid HD, the rest being long segment HD (the proximal most level being the splenic flexure. The average duration of surgery was 175 minutes (range, 130-245 minutes. The average blood loss was 45 ml. The average hospital stay was 7.2 days (range: 6-10 days. The major postoperative complications (n=3 included postoperative adhesive intestinal obstruction, anastomotic leak and persistent constipation due to residual aganglionosis. Each required a re-exploration. Minor complications included surgical site infection (n=3 and post-operative enterocolitis (n=3, which were managed conservatively. Six patients had constipation for a limited period post-operatively. All patients have a satisfactory functional outcome and normal development and growth. Conclusions: For HD, we recommend that single-stage Modified Duhamel procedure should be the preferred approach in view of its low morbidity, satisfactory functional outcome and avoidance of stoma, multiple surgeries and economic benefit in view of decreased hospital stay.

Lot-sizing for a single-stage single-product production system with rework of perishable production defectives

NARCIS (Netherlands)

Teunter, R.; Flapper, S.D.P.

2003-01-01

We consider a single-stage single-product production system. Produced units may be non-defective, reworkable defective, or non-reworkable defective. The system switches between production and rework. After producing a fixed number (N) of units, all reworkable defective units are reworked. Reworkable

Reproducibility of the pink esthetic score--rating soft tissue esthetics around single-implant restorations with regard to dental observer specialization.

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Gehrke, Peter; Lobert, Markus; Dhom, Günter

2008-01-01

The pink esthetic score (PES) evaluates the esthetic outcome of soft tissue around implant-supported single crowns in the anterior zone by awarding seven points for the mesial and distal papilla, soft-tissue level, soft-tissue contour, soft-tissue color, soft-tissue texture, and alveolar process deficiency. The aim of this study was to measure the reproducibility of the PES and assess the influence exerted by the examiner's degree of dental specialization. Fifteen examiners (three general dentists, three oral maxillofacial surgeons, three orthodontists, three postgraduate students in implant dentistry, and three lay people) applied the PES to 30 implant-supported single restorations twice at an interval of 4 weeks. Using a 0-1-2 scoring system, 0 being the lowest, 2 being the highest value, the maximum achievable PES was 14. At the second assessment, the photographs were scored in reverse order. Differences between the two assessments were evaluated with the Spearman's rank correlation coefficient (R). The Wilcoxon signed-rank test was used for comparisons of differences between the ratings. A significance level of p esthetic restorations showed the smallest deviations. Orthodontists were found to have assigned significantly poorer ratings than any other group. The assessment of postgraduate students and laypersons were the most favorable. The PES allows for a more objective appraisal of the esthetic short- and long-term results of various surgical and prosthetic implant procedures. It reproducibly evaluates the peri-implant soft tissue around single-implant restorations and results in good intra-examiner agreement. However, an effect of observer specialization on rating soft-tissue esthetics can be shown.

The Formation of High-Coercivity, Oriented, Nanophase Cobalt Precipitates in Al2O3 single cyrstals by ion implantation

International Nuclear Information System (INIS)

Honda, S.; Modine, F.A.; Haynes, T.E.; Meldrum, A.; Budai, J.D.; SOng, K.J.; Thompson, J.R.; Boatner, L.A.

1999-01-01

Ion-implantation and thermal-processing methods have been used to form nanophase magnetic precipitates of metallic cobalt that are embedded in the near-surface region of single crystals of Al 2 O 3 . The Co precipitates are isolated, single-crystal particles that are crystallographically oriented with respect to the host Al 2 O 3 lattice. Embedded nanophase Co precipitates were formed by the implantation of Co+ at an energy of 140 keV and a dose of 8 x l0 16 ions/cm 2 followed by annealing in a reducing atmosphere. The implanted/annealed Co depth profile, particle size distributions and shapes, and the orientational relationship between the nanophase precipitates and the host crystal lattice were determined using RBS/channeling, transmission electron microscopy, and x-ray diffraction

Consequences of Stimulus Type on Higher-Order Processing in Single-Sided Deaf Cochlear Implant Users.

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Finke, Mareike; Sandmann, Pascale; Bönitz, Hanna; Kral, Andrej; Büchner, Andreas

2016-01-01

Single-sided deaf subjects with a cochlear implant (CI) provide the unique opportunity to compare central auditory processing of the electrical input (CI ear) and the acoustic input (normal-hearing, NH, ear) within the same individual. In these individuals, sensory processing differs between their two ears, while cognitive abilities are the same irrespectively of the sensory input. To better understand perceptual-cognitive factors modulating speech intelligibility with a CI, this electroencephalography study examined the central-auditory processing of words, the cognitive abilities, and the speech intelligibility in 10 postlingually single-sided deaf CI users. We found lower hit rates and prolonged response times for word classification during an oddball task for the CI ear when compared with the NH ear. Also, event-related potentials reflecting sensory (N1) and higher-order processing (N2/N4) were prolonged for word classification (targets versus nontargets) with the CI ear compared with the NH ear. Our results suggest that speech processing via the CI ear and the NH ear differs both at sensory (N1) and cognitive (N2/N4) processing stages, thereby affecting the behavioral performance for speech discrimination. These results provide objective evidence for cognition to be a key factor for speech perception under adverse listening conditions, such as the degraded speech signal provided from the CI. © 2016 S. Karger AG, Basel.

The use of single point incremental forming for customized implants of unicondylar knee arthroplasty: a review

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Pankaj Kailasrao Bhoyar

Full Text Available Abstract Introduction The implantable devices are having enormous market. These products are basically made by traditional manufacturing process, but for the custom-made implants Incremental Sheet Forming is a paramount alternative. Single Point Incremental Forming (SPIF is a manufacturing process to form intricate, asymmetrical components. It forms the component using stretching and bending by maintaining materials crystal structure. SPIF process can be performed using conventional Computer Numerical Control (CNC milling machine. Review This review paper elaborates the various manufacturing processes carried on various biocompatible metallic and nonmetallic customised implantable devices. Conclusion Ti-6Al-4V alloy is broadly used for biomedical implants, but in this alloy, Vanadium is toxic so this alloy is not compatible for implants. The attention of researchers is towards the non toxic and suitable biocompatible materials. For this reason, a novel approach was developed in order to enhance the mechanical properties of this material. . The development of incremental forming technique can improve the formability of existing alloys and may meet the current strict requirements for performance of dies and punches.

Stress Distribution in Single Dental Implant System: Three-Dimensional Finite Element Analysis Based on an In Vitro Experimental Model.

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Rezende, Carlos Eduardo Edwards; Chase-Diaz, Melody; Costa, Max Doria; Albarracin, Max Laurent; Paschoeto, Gabriela; Sousa, Edson Antonio Capello; Rubo, José Henrique; Borges, Ana Flávia Sanches

2015-10-01

This study aimed to analyze the stress distribution in single implant system and to evaluate the compatibility of an in vitro model with finite element (FE) model. The in vitro model consisted of Brånemark implant; multiunit set abutment of 5 mm height; metal-ceramic screw-retained crown, and polyurethane simulating the bone. Deformations were recorded in the peri-implant region in the mesial and distal aspects, after an axial 300 N load application at the center of the occlusal aspect of the crown, using strain gauges. This in vitro model was scanned with micro CT to design a three-dimensional FE model and the strains in the peri-implant bone region were registered to check the compatibility between both models. The FE model was used to evaluate stress distribution in different parts of the system. The values obtained from the in vitro model (20-587 με) and the finite element analysis (81-588 με) showed agreement among them. The highest stresses because of axial and oblique load, respectively were 5.83 and 40 MPa for the cortical bone, 55 and 1200 MPa for the implant, and 80 and 470 MPa for the abutment screw. The FE method proved to be effective for evaluating the deformation around single implant. Oblique loads lead to higher stress concentrations.

Positional changes of maxillary central incisors following orthodontic treatment using single-crown implants as fixed reference markers.

Science.gov (United States)

Brahem, E B; Holm, B; Sonnesen, L; Worsaae, N; Gotfredsen, K

2017-12-01

This follow-up study (1) compares tooth displacement of central incisors in patients with and without pre-implant orthodontic treatment and (2) investigates whether sex, age, or orthodontic retention have an effect on tooth displacement after the insertion of single-crown implants. Fifty-seven patients - thirty-seven with (test group) and twenty without pre-implant orthodontic treatment (control group) - were rehabilitated with 89 single-crown implants in the upper maxilla. Clinical and radiographic data, clinical photographs, and dental casts were collected during baseline examinations after prosthetic rehabilitation and at the final follow-up examination at least 5 years later. A total of 114 dental casts were digitalized and aligned using a software program to measure changes in the positions of the central incisors. After a follow-up period of at least five years, 87% of the central incisors measured in the test group were displaced >0.25 mm vertically compared with 70% in the control group. Seventy-eight percent of the test group teeth had moved >0.25 mm horizontally compared with 55% in the control group. These differences were not significant, and there were no significant correlations with patient age or sex. The majority of patients had minor vertical (60%) or horizontal (67%) tooth displacement of the central incisors (0.25-0.75 mm) after a minimum follow-up period of 5 years. This study found no significant differences in tooth displacement comparing patients with and without pre-implant orthodontic treatment. No significant effect of sex, age, orthodontic retention, or implant location was observed on tooth displacement. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Fringe-shifting single-projector moiré topography application for cotyle implantate abrasion measurement

Science.gov (United States)

Rössler, Tomáš; Hrabovský, Miroslav; Pluháček, František

2005-08-01

The cotyle implantate is abraded in the body of patient and its shape changes. Information about the magnitude of abrasion is contained in the result contour map of the implantate. The locations and dimensions of abraded areas can be computed from the contours deformation. The method called the single-projector moire topography was used for the contour lines determination. The theoretical description of method is given at first. The design of the experimental set-up follows. The light grating projector was developed to realize the periodic structure on the measured surface. The method of fringe-shifting was carried out to increase the data quantity. The description of digital processing applied to the moire grating images is introduced at the end together with the examples of processed images.

Annealing effect of H+ -implanted single crystal silicon on strain and crystal structure

International Nuclear Information System (INIS)

Duo Xinzhong; Liu Weili; Zhang Miao; Gao Jianxia; Fu Xiaorong; Lin Chenglu

2000-01-01

The work focuses on the rocking curves of H + -implanted single silicon crystal detected by Four-Crystal X-ray diffractometer. The samples were annealed under different temperatures. Lattice defect in H + -implanted silicon crystals was detected by Rutherford Backscattering Spectrometry. It appeared that H-related complex did not crush until annealing temperature reached about 400 degree C. At that temperature H 2 was formed, deflated in silicon lattice and strained the lattice. But defects did not come into being in large quantity. The lattice was undamaged. When annealing temperature reached 500 degree C, strain induced by H 2 deflation crashed the silicon lattice. A large number of defects were formed. At the same time bubbles in the crystal and blister/flaking on the surface could be observed

Delayed breast implant reconstruction

DEFF Research Database (Denmark)

Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

2012-01-01

We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... of radiation therapy was associated with a non-significantly increased risk of reoperation after both 1-stage (HR = 1.4; 95% CI: 0.7-2.5) and 2-stage (HR = 1.6; 95% CI: 0.9-3.1) procedures. Reconstruction failure was highest (13.2%) in the 2-stage procedures with a history of radiation therapy. Breast...... reconstruction approaches other than implants should be seriously considered among women who have received radiation therapy....

Single-stage versus two-stage anaerobic fluidized bed bioreactors in treating municipal wastewater: Performance, foulant characteristics, and microbial community.

Science.gov (United States)

Wu, Bing; Li, Yifei; Lim, Weikang; Lee, Shi Lin; Guo, Qiming; Fane, Anthony G; Liu, Yu

2017-03-01

This study examined the receptive performance, membrane foulant characteristics, and microbial community in the single-stage and two-stage anaerobic fluidized membrane bioreactor (AFMBR) treating settled raw municipal wastewater with the aims to explore fouling mechanisms and microbial community structure in both systems. Both AFMBRs exhibited comparable organic removal efficiency and membrane performances. In the single-stage AFMBR, less soluble organic substances were removed through biosorption by GAC and biodegradation than those in the two-stage AFMBR. Compared to the two-stage AFMBR, the formation of cake layer was the main cause of the observed membrane fouling in the single-stage AFMBR at the same employed flux. The accumulation rate of the biopolymers was linearly correlated with the membrane fouling rate. In the chemical-cleaned foulants, humic acid-like substances and silicon were identified as the predominant organic and inorganic fouants respectively. As such, the fluidized GAC particles might not be effective in removing these substances from the membrane surfaces. High-throughout pyrosequencing analysis further revealed that beta-Proteobacteria were predominant members in both AFMBRs, which contributed to the development of biofilms on the fluidized GAC and membrane surfaces. However, it was also noted that the abundance of the identified dominant in the membrane surface-associated biofilm seemed to be related to the permeate flux and reactor configuration. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

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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.

CLINICAL CONSIDERATIONS OF DENTAL IMPLANT SYSTEM IN IMMEDIATE LOADING IMPLANT CASES

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Carolina Damayanti Marpaung

2015-06-01

Full Text Available Immediate loading of dental implant has been researched intensively in the development of Branemark’s early concept of 2 stages implant placement. This was embarked from both patients and practiitioner’s convenience towards a simpler protocol and shorter time frame. Many recent researchers later found that micromotions derived from occlusal loading for a certain degree, instead of resulting a fibrous tissue encapsulation, can enhance the osseointegration process. Dental Implant system enhancement towards maximizing the primary stability held a key factor in Branemark’s concept development. Surgical protocol and implant design was found to give a significant contribution to the prognosis of immediate-loading implants.

Safety and efficacy of Implanon, a single-rod implantable contraceptive containing etonogestrel.

Science.gov (United States)

Funk, Sidney; Miller, Michael M; Mishell, Daniel R; Archer, David F; Poindexter, Alfred; Schmidt, Juergen; Zampaglione, Edio

2005-05-01

The safety and efficacy of a single-rod implantable contraceptive containing etonogestrel (Implanontrade mark) were investigated in a multicenter clinical trial. Sexually active American women (N=330) with apparently normal menstrual cycles used the implant for up to 2 years. All subjects recorded bleeding and/or spotting daily in a diary. Safety was assessed through adverse experiences (AEs), laboratory tests and physical and gynecologic examinations. Total exposure was 474 woman-years (6186 cycles), and 68% of subjects had at least 1 year of exposure. No pregnancies occurred. The most common bleeding pattern observed throughout the study was infrequent bleeding, defined as less than three episodes of bleeding in a reference period (excluding amenorrhea). The least common pattern was frequent bleeding, defined as more than five episodes of bleeding in a reference period. Infrequent, prolonged and frequent bleeding patterns were most common early in the study and declined thereafter. During the 3-month Reference Periods 2-8 (Months 4-24), the incidence of amenorrhea ranged from 14% to 20%. Forty-three subjects (13%) withdrew from the study because of bleeding pattern changes and 76 subjects (23%) discontinued because of other AEs. Other common AEs leading to discontinuation, besides bleeding irregularities, were emotional lability (6.1%), weight increase (3.3%), depression (2.4%) and acne (1.5%). Use of Implanon (etonogestrel subdermal implant, referred to herein as ENG implant) for up to 2 years had no clinically significant effects on laboratory parameters, physical and pelvic examinations, vital signs or body mass index. The average length of time required for ENG implant insertion and that for removal were 0.5 and 3.5 min, respectively, and all the procedures were uncomplicated. The return to normal menstrual cycles and fertility was rapid after removal. Implanon is a safe, highly effective and rapidly reversible new method of contraception.

Single-stage anterior high sacrectomy for locally recurrent rectal cancer.

Science.gov (United States)

Fawaz, Khaled; Khaled, Fawaz; Smith, Myles J; Moises, Cukier; Smith, Andrew J; Yee, Albert J M

2014-03-01

A review of prospectively collected data on a consecutive series of patients undergoing single-stage anterior high sacrectomy for locally recurrent rectal carcinoma (LRRC). To determine the clinical outcome of patients who underwent anterior high sacrectomy for LRRC. High sacrectomy for oncological resection remains technically challenging. Surgery has the potential to achieve cure in carefully selected patients. Complete (R0) tumor excision in LRRC may require sacrectomy. High sacral resections (S3 and above) typically require a combined anterior/supine and posterior/prone procedure. We investigated our experience performing single-stage anterior high sacrectomy for LRRC. A consecutive series of patients with LRRC without systemic metastases who underwent resection with curative intent requiring high sacrectomy were identified. A review of a prospectively maintained colorectal and spine cancer database data was performed. An oblique dome high sacral osteotomy was performed during a single-stage anterior procedure. Outcome measures included surgical resection margin status, hospital length of stay, postoperative complications, physical functioning status, and overall survival. Nineteen consecutive patients were treated between 2002 and 2011. High sacrectomy was performed at sacral level S1-S2 in 4 patients, S2-S3 in 9 patients, and through S3 in 6 patients. An R0 resection margin was achieved histologically in all 19 cases. There was 1 early (<30 d) postoperative death (1/19, 5%). At median follow-up of 38 months, 13 patients had no evidence of residual disease, 1 was alive with disease, and 4 had died of disease. Morbidities occurred in 15 of the 19 patients (79%). Although high sacrectomy may require a combined anterior and posterior surgical approach, our series demonstrates the feasibility of performing single-stage anterior high sacrectomy in LRRC, with acceptable risks and outcomes compared with the literature. The procedure described by us for LRRC lessens

Killing effect of EGFR-TKI combined with 125I seed implantation therapy on ⅢB-Ⅳ stage lung cancer tissue

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Ai-Sheng Xiang

2016-12-01

Full Text Available Objective: To analyze the killing effect of EGFR-TKI combined with 125I seed implantation therapy on ⅢB-Ⅳ stage lung cancer tissue. Methods: A total of 78 patients with ⅢB-Ⅳ stage lung cancer were randomly divided into observation group and control group (n=39, control group received EGFR-TKI treatment and observation group received EGFR-TKI combined with 125I seed implantation therapy. Differences in apoptosis gene, invasion gene and autophagy gene expression in lung tissue were compared between two groups after 1 month of treatment. Results: Apoptosis genes PDCD5, bax and bcl-xS mRNA expression levels in lung tissue of observation group after 1 month of treatment were higher than those of control group while Bag-1, survivin and bcl-xL mRNA expression levels were lower than those of control group; invasion genes CD147, EGFR and DDX17 mRNA expression levels were lower than those of control group while Bin1, E-cadherin and Ovol2 mRNA expression levels were higher than those of control group; autophagy genes ARHI, Beclin1, Atg5, LC3B, pULK and PI3KC3 mRNA expression levels were higher than those of control group. Conclusions: EGFR-TKI combined with 125I seed implantation therapy can enhance the tumor killing effect on patients with ⅢB-Ⅳ stage lung cancer, and contribute to the optimization of overall condition and the extension of survival time.

Iodine-125 implants for carcinoma of the prostate

International Nuclear Information System (INIS)

Peschel, R.E.; Fogel, T.D.; Kacinski, B.M.; Kelly, K.; Mate, T.P.

1985-01-01

One hundred-thirteen patients underwent Iodine-125 prostate implant and lymphadenectomy at Yale-New Haven Hospital from 1974 through 1980. The distribution by clinical stage was: 7 Stage A2, 86 Stage B, and 20 Stage C patients. Ninety-four patients had a negative lymphadenectomy and 19 patients (17%) had metastatic disease in the pelvic lymph nodes (N+). The actuarial 5-year survival for all 113 patients was 87%. Local tumor control was 85% for all Stage B patients and 75% for all Stage C patients. Only 10 patients (9%) have developed long-term gastrointestinal or genitourinary complications following their implant. Iodine-125 implant appears to be a reasonable alternate form of therapy in highly selected groups of patients with carcinoma of the prostate

Immediate non-occlusal loading of single implants in the aesthetic zone : A randomized clinical trial

NARCIS (Netherlands)

den Hartog, Laurens; Raghoebar, Gerry M.; Stellingsma, Kees; Vissink, Arjan; Meijer, Henny J. A.

P>Aim This study compared the outcome of immediate non-occlusal loading with conventional loading for single implants in the maxillary aesthetic zone. It was hypothesized that immediate non-occlusal loading is not inferior to conventional loading. Materials and Methods Sixty-two patients with a

Displacement of screw-retained single crowns into implants with conical internal connections.

Science.gov (United States)

Yilmaz, Burak; Seidt, Jeremy D; McGlumphy, Edwin A; Clelland, Nancy L

2013-01-01

Internal conical implant-abutment connections without platforms may lead to axial displacement of crowns during screw tightening. This displacement may affect proximal contacts, incisal edge position, or occlusion. This study aimed to measure the displacement of screw-retained single crowns into an implant in three dimensions during screw tightening by hand or via torque driver. A stereolithic acrylic resin cast was created using computed tomography data from a patient missing the maxillary right central incisor. A 4.0- × 11-mm implant was placed in the edentulous site. Five porcelain-fused-to-metal single crowns were made using "cast-to" abutments. Crowns were tried on the stereolithic model, representing the patient, and hand tightened. The spatial relationship of crowns to the model after hand tightening was determined using three-dimensional digital image correlation (3D DIC), an optical measurement technique. The crowns were then tightened using a torque driver to 20 Ncm and the relative crown positions were again recorded. Testing was repeated three times for each crown, and displacement of the crowns was compared between the hand-tightened and torqued states. Commercial image correlation software was used to analyze the data. Mean vertical and horizontal crown displacement values were calculated after torqueing. The interproximal contacts were evaluated before and after torquing using an 8-μm aluminum foil shim. There were vertical and horizontal differences in crown positions between hand tightening and torqueing. Although these were small in magnitude, detectable displacements occurred in both apical and facial directions. After hand tightening, the 8-μm shim could be dragged without tearing. However, after torque tightening, the interproximal contacts were too tight and the 8-μm shim could not be dragged without tearing. Differences between hand tightening and torque tightening should be taken into consideration during laboratory and clinical

Slow drilling speeds for single-drill implant bed preparation. Experimental in vitro study.

Science.gov (United States)

Delgado-Ruiz, R A; Velasco Ortega, E; Romanos, G E; Gerhke, S; Newen, I; Calvo-Guirado, J L

2018-01-01

To evaluate the real-time bone temperature changes during the preparation of the implant bed with a single-drill protocol with different drill designs and different slow drilling speeds in artificial type IV bone. For this experimental in vitro study, 600 implant bed preparations were performed in 10 bovine bone disks using three test slow drilling speeds (50/150/300 rpm) and a control drilling speed (1200 rpm). The temperature at crestal and apical areas and time variations produced during drilling with three different drill designs with similar diameter and length but different geometry were recorded with real-life thermographic analysis. Statistical analysis was performed by two-way analysis of variance. Multiple comparisons of temperatures and time with the different drill designs and speeds were performed with the Tukey's test. T Max values for the control drilling speed with all the drill designs (D1 + 1200; D2 + 1200; D3 + 1200) were higher compared to those for the controls for 11 ± 1.32 °C (p drilling at 50 rpm resulted in the lowest temperature increment (22.11 ± 0.8 °C) compared to the other slow drilling speeds of 150 (24.752 ± 1.1 °C) and 300 rpm (25.977 ± 1.2 °C) (p drilling speeds compared to that for the control drilling speed. Slow drilling speeds required significantly more time to finish the preparation of the implant bed shown as follows: 50 rpm > 150 rpm > 300 rpm > control (p drill protocol with slow drilling speeds (50, 150, and 300 rpm) without irrigation in type IV bone increases the temperature at the coronal and apical levels but is below the critical threshold of 47 °C. The drill design in single-drill protocols using slow speeds (50, 150, and 300 rpm) does not have an influence on the thermal variations. The time to accomplish the implant bed preparation with a single-drill protocol in type IV bone is influenced by the drilling speed and not by the drill design. As the speed decreases, then

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.

Transcatheter aortic-valve implantation with one single minimal contrast media injection.

Science.gov (United States)

Arrigo, Mattia; Maisano, Francesco; Haueis, Sabine; Binder, Ronald K; Taramasso, Maurizio; Nietlispach, Fabian

2015-06-01

Performing transcatheter aortic valve implantation (TAVI) with the use of minimal contrast in patients at high-risk for acute kidney injury (AKI). Contrast-induced nephropathy (CIN) is a major cause of AKI following TAVI and is associated with increased morbidity and mortality. The amount of contrast media used increases the risk for CIN. Computed tomography was omitted during the screening process. For the procedure transfemoral access was default. The self-expanding CoreValve prosthesis was chosen in all patients to minimize the risk of annular rupture in case of oversizing. Valve sizing was based on echocardiography, aortography, calcification on fluoroscopy, as well as weight and height of the patient. A single contrast injection was performed to confirm correct position of the pigtail catheter at the level of the annulus. The pigtail then served as the marker for the device landing zone. Intraprocedural assessment of the implantation result relied on echocardiography and hemodynamics. Five patients with severe aortic stenosis and at high risk for developing CIN were included. Device success was achieved in all patients and no major complications occurred. The median dose of injected contrast media was 8 ml (4-9). All but one patient had improved renal function after the intervention compared to baseline. Our study shows feasibility of performing TAVI with a single minimal contrast media injection, using a self-expandable valve. This technique has the potential to reduce the incidence of CIN. © 2015 Wiley Periodicals, Inc.

System and method for single-phase, single-stage grid-interactive inverter

Science.gov (United States)

Liu, Liming; Li, Hui

2015-09-01

The present invention provides for the integration of distributed renewable energy sources/storages utilizing a cascaded DC-AC inverter, thereby eliminating the need for a DC-DC converter. The ability to segment the energy sources and energy storages improves the maintenance capability and system reliability of the distributed generation system, as well as achieve wide range reactive power compensation. In the absence of a DC-DC converter, single stage energy conversion can be achieved to enhance energy conversion efficiency.

Sinus Floor Elevation with Modified Crestal Approach and Single Loaded Short Implants: A Case Report with 4 Years of Follow-Up

Directory of Open Access Journals (Sweden)

Michele Perelli

2017-01-01

Full Text Available Tooth extraction is usually followed by bone reduction. In the maxillary posterior region, this remodelling combined with sinus pneumatisation and periodontal defects may lead to a reduced basal bone height available for implant placement. Sinus floor elevation can be performed with different surgical techniques. Crestal approach has demonstrated to be effective, less invasive, and associated with a reduced morbidity. This article reports a modified sinus floor elevation by means of rotary, noncutting instruments, addition of xenograft, and 2 short-threaded implant placements. The aim of the study was to evaluate the implant’s success and intrasinus radiographical bone gain after 4 years of functional loading. The premolar implant site presented a starting basal bone height of 6 mm, while the molar site was of 2 mm. In the first surgical step, sinus floor elevation was performed mesially and the implant was inserted, and distally only sinus floor elevation was performed. After 6 months, the mesial implant was uncovered and the second implant was inserted; 4 months later, the second fixture was uncovered, and both fixtures were loaded with single provisional screw-retained crowns and later with single screw-retained porcelain fused to metal crowns. Implants integrated successfully, and crestal bone remodelling did not exceed the smooth collar. Bone gain was 3 mm for the mesial implant and more than 5 mm for the distal one.

Hybrid approach of ventricular assist device and autologous bone marrow stem cells implantation in end-stage ischemic heart failure enhances myocardial reperfusion

Directory of Open Access Journals (Sweden)

Khayat Andre

2011-01-01

Full Text Available Abstract We challenge the hypothesis of enhanced myocardial reperfusion after implanting a left ventricular assist device together with bone marrow mononuclear stem cells in patients with end-stage ischemic cardiomyopathy. Irreversible myocardial loss observed in ischemic cardiomyopathy leads to progressive cardiac remodelling and dysfunction through a complex neurohormonal cascade. New generation assist devices promote myocardial recovery only in patients with dilated or peripartum cardiomyopathy. In the setting of diffuse myocardial ischemia not amenable to revascularization, native myocardial recovery has not been observed after implantation of an assist device as destination therapy. The hybrid approach of implanting autologous bone marrow stem cells during assist device implantation may eventually improve native cardiac function, which may be associated with a better prognosis eventually ameliorating the need for subsequent heart transplantation. The aforementioned hypothesis has to be tested with well-designed prospective multicentre studies.

RBS/channeling analysis of hydrogen-implanted single crystals of FZ silicon and 6H silicon

International Nuclear Information System (INIS)

Irwin, R.B.

1984-01-01

Single crystals of FZ silicon and 6H silicon carbide were implanted with hydrogen ions (50 and 80 keV, respectively) to fluences from 2 x 10 16 H + /cm 2 to 2 x 10 18 H+/cm 2 . The implantations were carried out at three temperatures: approx.95K, 300 K, and approx.800 K. Swelling of the samples was measured by surface profilometry. RBS/channeling was used to obtain the damage profiles and to determine the amount of hydrogen retained in the lattice. The damage profiles are centered around X/sub m/ for the implants into silicon and around R/sub p/ for silicon carbide. For silicon carbide implanted at 95 K and 300 K and for silicon implanted at 95 K, the peak damage region is amorphous for fluences above 8 x 10 16 H + /cm 2 , 4 x 10 17 H + /cm 2 , and 2 x 10 17 H + /cm 2 , respectively. Silicon implanted at 300 and 800 K and silicon carbide implanted at 800 K remain crystalline up to fluences of 1 x 10 18 H + /cm 2 . The channeling damage results agree with previously reported TEM and electron diffraction data. The predictions of a simple disorder-accumulation model with a linear annealing term explains qualitatively the observed damage profiles in silicon carbide. Quantitatively, however, the model predicts faster development of the damage profiles than is observed at low fluences in both silicon and silicon carbide. For samples implanted at 300 and 800 K, the model also predicts substantially less peak disorder than is observed. The effect of the surface, the retained hydrogen, the shape of S/sub D/(X), and the need for a nonlinear annealing term may be responsible for the discrepancy

Strategies and limits in multi-stage single-point incremental forming

DEFF Research Database (Denmark)

Skjødt, Martin; Silva, M.B.; Martins, P. A. F.

2010-01-01

paths. The results also reveal that the sequence of multi-stage forming has a large effect on the location of strain points in the principal strain space. Strain paths are linear in the first stage and highly non-linear in the subsequent forming stages. The overall results show that the experimentally......Multi-stage single-point incremental forming (SPIF) is a state-of-the-art manufacturing process that allows small-quantity production of complex sheet metal parts with vertical walls. This paper is focused on the application of multi-stage SPIF with the objective of producing cylindrical cups......-limit curves and fracture forming-limit curves (FFLCs), numerical simulation, and experimentation, namely the evaluation of strain paths and fracture strains in actual multi-stage parts. Assessment of numerical simulation with experimentation shows good agreement between computed and measured strain and strain...

The experience of artificial urinary sphincter implantation by a single surgeon in 15 years.

Science.gov (United States)

Shen, Yuan-Chi; Chiang, Po-Hui

2013-03-01

Artificial urinary sphincter (AUS) is the gold standard treatment for urinary incontinence owing to sphincter incompetence. We reviewed our experience in AUS implantation. From 1995 to 2009, 19 patients underwent 25 AUS implantations performed by a single surgeon. The cause of incontinence was sphincter incompetence, which was secondary to prostate surgery, neurogenic bladder, radiation, and post-traumatic urethral lesion. Twenty-three prostheses were placed in the bulbar urethra for male patients: 11 AUS cuffs were placed through the perineal approach and 12 through the penoscrotal approach. Two procedures were applied over the bladder neck for the female patients. Through a retrospective review of charts, continence and complications were analyzed. The mean follow-up time was 50.0 ± 42.9 months (range: 2-146 months). There were 16 successful surgeries (64%), and these patients were free from the need for a pad. In eight surgeries (32%), the devices were removed due to infection, while one implantation (4%) was unsuccessful due to perforation into the bulbar urethra. There was a statistically significant difference (p = 0.024) in failure rates between patients who received radiotherapy (100%) and other patients (22.7%). There was no statistically significant difference in dry and revision rates (p > 0.05) between the perineal and penoscrotal approach. Accordingly, over half of the patients with total incontinence benefitted from AUS implantation. In consideration of the high failure rate for patients receiving radiotherapy, caution should be exercised in the use of implantation. Secondary implantation has a satisfactory success rate in selected patients. The same success rate was noted for both perineal and penoscrotal approaches. Copyright © 2013. Published by Elsevier B.V.

Embryonic mortality and intrauterine growth retardation (IUGR) associated with placental alterations in pregnant rats treated with methyl methanesulfonate (MMS) at the peri-implantation stage.

Science.gov (United States)

Yokoi, Ryohei; Hayashi, Morimichi; Tamura, Toru; Kobayashi, Kazuo; Kuroda, Junji; Kusama, Hiroshi; Kagami, Hiroshi; Ono, Tamao

2008-12-01

Embryonic mortality and intrauterine growth retardation (IUGR) are induced by exposure of rodents to xenobiotic agents during the pregastrulation period of development. We examined the time course of the effects of methyl methanesulfonate (MMS), an alkylating agent, on conceptus development in order to clarify the relative roles of the embryo and the placenta in their induction. Pregnant rats were treated orally with a single dose of MMS (200 mg/kg) in the morning of gestation day (GD) 6 (peri-implantation stage). Embryonic mortality was increased on GD12 and thereafter by MMS treatment, with newly dead embryos showing placental hypoplasia at GD12. Embryo or fetal weight was also smaller for MMS-treated dams than for control dams from GD14 to GD20. The labyrinth zone and junctional zone (JZ) of the placenta were thinner in MMS-treated rats from GD12 to GD17 and from GD12 to GD20 (except for GD17), respectively. Furthermore, MMS-treated dams showed a smaller number of glycogen cells in the JZ on GD14. In contrast, the placental glycogen concentration was higher and the expression of glucose transporter 1 in the JZ remained at GD20. These results indicate that exposure of pregnant rats to MMS at the peri-implantation stage of embryogenesis affects placental development and growth. The placental impairment induced by MMS was likely responsible for the embryonic death observed 6 days after exposure of dams to this agent as well as for the IUGR of surviving embryos or fetuses throughout the gestation period.

Evaluation of an automated single-channel sleep staging algorithm

Directory of Open Access Journals (Sweden)

Wang Y

2015-09-01

Full Text Available Ying Wang,1 Kenneth A Loparo,1,2 Monica R Kelly,3 Richard F Kaplan1 1General Sleep Corporation, Euclid, OH, 2Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH, 3Department of Psychology, University of Arizona, Tucson, AZ, USA Background: We previously published the performance evaluation of an automated electroencephalography (EEG-based single-channel sleep–wake detection algorithm called Z-ALG used by the Zmachine® sleep monitoring system. The objective of this paper is to evaluate the performance of a new algorithm called Z-PLUS, which further differentiates sleep as detected by Z-ALG into Light Sleep, Deep Sleep, and Rapid Eye Movement (REM Sleep, against laboratory polysomnography (PSG using a consensus of expert visual scorers. Methods: Single night, in-lab PSG recordings from 99 subjects (52F/47M, 18–60 years, median age 32.7 years, including both normal sleepers and those reporting a variety of sleep complaints consistent with chronic insomnia, sleep apnea, and restless leg syndrome, as well as those taking selective serotonin reuptake inhibitor/serotonin–norepinephrine reuptake inhibitor antidepressant medications, previously evaluated using Z-ALG were re-examined using Z-PLUS. EEG data collected from electrodes placed at the differential-mastoids (A1–A2 were processed by Z-ALG to determine wake and sleep, then those epochs detected as sleep were further processed by Z-PLUS to differentiate into Light Sleep, Deep Sleep, and REM. EEG data were visually scored by multiple certified polysomnographic technologists according to the Rechtschaffen and Kales criterion, and then combined using a majority-voting rule to create a PSG Consensus score file for each of the 99 subjects. Z-PLUS output was compared to the PSG Consensus score files for both epoch-by-epoch (eg, sensitivity, specificity, and kappa and sleep stage-related statistics (eg, Latency to Deep Sleep, Latency to REM

Systematic Review of Soft Tissue Alterations and Esthetic Outcomes Following Immediate Implant Placement and Restoration of Single Implants in the Anterior Maxilla.

Science.gov (United States)

Khzam, Nabil; Arora, Himanshu; Kim, Paul; Fisher, Anthony; Mattheos, Nikos; Ivanovski, Saso

2015-12-01

The aim of this review is to assess the outcome of single-tooth immediate implant placement and restoration (IPR) in the maxillary anterior region, with a particular emphasis on soft tissue and esthetic outcomes. An electronic search in Medline, EBSCOhost, and Ovid (PubMed) was performed to identify studies that reported on soft tissue outcomes following immediate placement and restoration of implants in the maxillary esthetic region with a mean follow-up of ≥1 year. Nineteen studies on single implants inserted immediately into fresh extraction sockets and provisionally restored in the maxillary esthetic region were included. Soft tissue changes were found to be acceptable, with most studies reporting mean gingival recession of 0.27 ± 0.38 mm and mean papillary height loss of 0.23 ± 0.27 mm after follow-up of ≥1 year. Advanced buccal recession (>1 mm) occurred in 11% of cases. Long-term follow-up studies (>2 years) reported that the interdental papillae, in particular, showed a tendency to rebound over time. The few studies that reported on patient-centered outcomes showed a high level of patient satisfaction with the outcomes of IPR treatment. The IPR protocol resulted in generally acceptable soft tissue and esthetic outcomes, with suboptimal results reported in ≈11% of low-risk cases. Factors such as preoperative tissue biotype or use of a flap or connective tissue graft did not significantly influence soft tissue and esthetic outcomes. Long-term prospective controlled clinical trials are necessary to identify factors that may influence the esthetic outcomes associated with IPR.

Use of skin stretchers for single-stage bilateral mastectomies in a dog and a cat.

Science.gov (United States)

Miyazaki, Yuta; Aikawa, Takeshi; Shimatsu, Taichi; Nishimura, Masaaki; Sadahiro, Shigeo

2018-04-01

To describe the application of skin stretchers for closure of single-stage bilateral mastectomies in a dog and a cat. Clinical case report. A 12-year-old intact female Miniature Dachshund and a 13-year-old spayed female domestic short-hair cat. Skin stretchers were applied to the site of the skin adjacent to mammary glands for 2-4 days before surgery. Cable tension was adjusted every 6-8 hours to elongate the skin and to achieve primary closure of single-stage bilateral mastectomy without tension. Wound closure after single-stage bilateral mastectomy was achieved without tension or major complication in both animals. Use of skin stretchers allows primary closure of single-stage bilateral mastectomy in dogs and cats. © 2017 The American College of Veterinary Surgeons.

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.

Titanium and polyether ether ketone (PEEK) patient-specific sub-periosteal implants: two novel approaches for rehabilitation of the severely atrophic anterior maxillary ridge.

Science.gov (United States)

Mounir, M; Atef, M; Abou-Elfetouh, A; Hakam, M M

2018-05-01

The aim of this study was to assess two new protocols for single-stage rehabilitation of the severely atrophic maxillary ridge using customized porous titanium or polyether ether ketone (PEEK) sub-periosteal implants. Ten patients with a severely atrophic anterior maxillary alveolar ridge were divided randomly into two groups (five patients in each) to receive customized sub-periosteal implants fabricated via CAD/CAM technology: group 1, porous titanium implants; group 2, PEEK implants. Prosthetic loading with fixed acrylic bridges was performed 1 month postoperative. The implants were followed-up for 12 months and evaluated for the presence of any sign of radiographic bone resorption, mobility, infection, prosthetic fracture, or implant exposure. The immediate postoperative period was uneventful except for one case complicated by wound dehiscence in group 1. At 12 months, all implants were functionally stable and the patients were comfortable with the prostheses. No signs of radiographic bone resorption, mobility, infection, or prosthetic fracture were observed. Within the limitations of this study, the application of customized porous titanium and PEEK sub-periosteal implants produced through CAD/CAM technology appears to be an acceptable method for single-stage prosthetic rehabilitation of the severely atrophic edentulous anterior maxilla. This study was awarded the best case study at the academy of osseintegration annual meeting 2017, Orlando, Florida. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Low-Gain, Low-Noise Integrated Neuronal Amplifier for Implantable Artifact-Reduction Recording System

OpenAIRE

Zbrzeski, Adeline; Lewis, Noëlle; Rummens, Francois; Jung, Ranu; N'Kaoua, Gilles; Benazzouz, Abdelhamid; Renaud, Sylvie

2013-01-01

Brain neuroprostheses for neuromodulation are being designed to monitor the neural activity of the brain in the vicinity of the region being stimulated using a single macro-electrode. Using a single macro-electrode, recent neuromodulation studies show that recording systems with a low gain neuronal amplifier and successive amplifier stages can reduce or reject stimulation artifacts. These systems were made with off-the-shelf components that are not amendable for future implant design. A low-g...

Interventions for replacing missing teeth: Antibiotics in dental implant placement to prevent complications: Evidence summary of Cochrane review.

Science.gov (United States)

Jayaraman, Srinivasan

2015-01-01

The failure of dental implant can occurs at the preoperative planning stage, at the surgical stage, and at the postoperative stage. The success of this treatment can be increased if the clinical implant practice guidelines are prepared based on the recommendations from the highest level of research evidence (i.e.,) from systematic review of randomized controlled trials (RCTs) with meta-analysis. The Cochrane reviews of interventions are basically systematic reviews of RCTs with meta-analysis but follow a systematic methodological approach following the guidelines from Cochrane handbook for Systematic Reviews of Intervention. They give the current best evidence as they are updated every 2 years which is being the minimum period for an update. This evidence summary recommends the use of antibiotics, single dose of 2 g of amoxicillin 1 h prior to implant surgery to prevent implant failure, based on the body of evidence from the Cochrane review that was first published in 2003, 2008, and then updated twice in 2010 and 2013. The included studies are not from our population for the research question asked in this updated Cochrane review; hence, the need to do primary research in our population to support the available evidence is mandatory.

The efficacy of single-stage open intramedullary nailing of neglected femur fractures.

Science.gov (United States)

Boopalan, P R J V C; Sait, Azad; Jepegnanam, Thilak Samuel; Matthai, Thomas; Varghese, Viju Daniel

2014-02-01

Neglected femur fractures are not rare in the developing world. Treatment options include single-stage open reduction and intramedullary nailing, or open release, skeletal traction, and then second-stage open intramedullary nailing, with bone grafting. Single-stage procedures have the potential advantage of avoiding neurovascular complications secondary to acute lengthening, but they require a second operation, with potentially increased resource use and infection risk. We sought to determine the (1) likelihood of union, (2) complications and reoperations, and (3) functional results with single-stage open intramedullary nailing without bone grafting in patients with neglected femur fractures. Between January 2003 and December 2007, 17 consecutive patients presented to our practice with neglected femoral shaft fractures. All were treated with single-stage nailing without bone grafting. There were 15 men and two women with a median age of 27 years. The average time from fracture to treatment was 13 weeks (range, 4-44 weeks). Eleven patients underwent open nailing with interlocked nails and six were treated with cloverleaf Kuntscher nails. Patients were followed for a minimum of 6 months (mean, 33 months; range, 6-72 months). The mean preoperative ROM of the knee was 28° (range, 10°-150°) and femoral length discrepancy was 3.1 cm (range, 1-5 cm). All fractures united and the mean time to union was 16 weeks (range, 7-32 weeks). There were no neurologic complications secondary to acute lengthening. The mean postoperative ROM of the knee was 130° (range, 60°-150°). All patients were able to return to preinjury work. Sixteen patients regained their original femoral length. One-stage open intramedullary nailing of neglected femoral diaphyseal fractures without bone grafting was safe and effective, and obviated the need for a two-stage approach. Although the findings need to be replicated in larger numbers of patients, we believe this technique may be useful in

Nuclear reaction analysis of Ge ion-implanted ZnO bulk single crystals: The evaluation of the displacement in oxygen lattices

Science.gov (United States)

Kamioka, K.; Oga, T.; Izawa, Y.; Kuriyama, K.; Kushida, K.; Kinomura, A.

2014-08-01

The displacement of oxygen lattices in Ge ion-implanted ZnO bulk single crystals is studied by nuclear reaction analysis (NAR), photoluminescence (PL), and Van der Pauw methods. The Ge ion-implantation (net concentration: 2.6 × 1020 cm-3) into ZnO is performed using a multiple-step energy. The high resistivity of ∼103 Ω cm in un-implanted samples remarkably decreased to ∼10-2 Ω cm after implanting Ge-ion and annealing subsequently. NRA measurements of as-implanted and annealed samples suggest the existence of the lattice displacement of O atoms acting as acceptor defects. As O related defects still remain after annealing, these defects are not attributed to the origin of the low resistivity in 800 and 1000 °C annealed ZnO.

Synchrotron Topographic and Diffractometer Studies of Buried Layered Structures Obtained by Implantation with Swift Heavy Ions in Silicon Single Crystals

International Nuclear Information System (INIS)

Wierzchowski, W.; Wieteska, K.; Zymierska, D.; Graeff, W.; Czosnyka, T.; Choinski, J.

2006-01-01

A distribution of crystallographic defects and deformation in silicon crystals subjected to deep implantation (20-50 μm) with ions of the energy of a few MeV/amu is studied. Three different buried layered structures (single layer, binary buried structure and triple buried structure) were obtained by implantation of silicon single crystals with 184 MeV argon ions, 29.7 MeV boron ions, and 140 MeV argon ions, each implantation at a fluency of 1x10 14 ions cm -2 . The implanted samples were examined by means of white beam X-ray section and projection topography, monochromatic beam topography and by recording local rocking curves with the beam restricted to 50 x 50 μm 2 . The experiment pointed to a very low level of implantation-induced strain (below 10 -5 ). The white beam Bragg case section experiment revealed a layer producing district black contrast located at a depth of the expected mean ion range. The presence of these buried layered structures in studied silicon crystals strongly affected the fringe pattern caused by curvature of the samples. In case of white beam projection and monochromatic beam topographs the implanted areas were revealed as darker regions with a very tiny grain like structure. One may interpret these results as the effect of considerable heating causing annihilation of point defects and formation of dislocation loops connected with point defect clusters. (author)

Systemic alendronate treatment improves fixation of press-fit implants: a canine study using nonloaded implants

DEFF Research Database (Denmark)

Jensen, Thomas B; Bechtold, Joan E; Chen, Xinqian

2007-01-01

of alendronate treatment. Bone ongrowth (bone in contact with implant surface) was estimated using the linear intercept technique and shear strength was calculated as the slope on a load-displacement curve. For the press fit implants, alendronate treatment significantly increased bone ongrowth from 24% to 29...... early implant stability is an important predictor of longevity, systemic alendronate treatment could be an important clinical tool to positively influence the early stages of implant incorporation. Udgivelsesdato: 2007-Jun...

Binaural release from masking with single- and multi-electrode stimulation in children with cochlear implants.

Science.gov (United States)

Todd, Ann E; Goupell, Matthew J; Litovsky, Ruth Y

2016-07-01

Cochlear implants (CIs) provide children with access to speech information from a young age. Despite bilateral cochlear implantation becoming common, use of spatial cues in free field is smaller than in normal-hearing children. Clinically fit CIs are not synchronized across the ears; thus binaural experiments must utilize research processors that can control binaural cues with precision. Research to date has used single pairs of electrodes, which is insufficient for representing speech. Little is known about how children with bilateral CIs process binaural information with multi-electrode stimulation. Toward the goal of improving binaural unmasking of speech, this study evaluated binaural unmasking with multi- and single-electrode stimulation. Results showed that performance with multi-electrode stimulation was similar to the best performance with single-electrode stimulation. This was similar to the pattern of performance shown by normal-hearing adults when presented an acoustic CI simulation. Diotic and dichotic signal detection thresholds of the children with CIs were similar to those of normal-hearing children listening to a CI simulation. The magnitude of binaural unmasking was not related to whether the children with CIs had good interaural time difference sensitivity. Results support the potential for benefits from binaural hearing and speech unmasking in children with bilateral CIs.

Defects in N{sup +} ion-implanted ZnO single crystals studied by positron annihilation and Hall effect

Energy Technology Data Exchange (ETDEWEB)

Brauer, G.; Anwand, W.; Skorupa, W. [Institut fuer Ionenstrahlphysik und Materialforschung, Forschungszentrum Rossendorf, Dresden (Germany); Kuriplach, J.; Melikhova, O.; Cizek, J.; Prochazka, I. [Department of Low Temperature Physics, Faculty of Mathematics and Physics, Charles Univ., Prague (Czech Republic); Wenckstern, H. von; Brandt, M.; Lorenz, M.; Grundmann, M. [Institut fuer Experimentelle Physik II, Universitaet Leipzig (Germany)

2007-07-01

High quality ZnO single crystals of dimensions 10 x 10 x 0.5 mm{sup 3}, grown by a hydrothermal approach, have been implanted by 40 keV N{sup +} ions to a fluence of 1 x 10{sup 15} cm{sup -2} at room temperature. Their properties revealed by positron annihilation and Hall effect measurements are given in the as-grown and as-irradiated states, and after post-implantation annealing in an oxygen ambient at 200 C and 500 C. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Characterization of junctions produced by medium-energy ion implantation in silicon; Caracterisation de jonctions obtenues par implantation d'ions de moyenne energie dans le silicium

Energy Technology Data Exchange (ETDEWEB)

Monfret, A [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1970-07-01

Characteristics of diodes made by implanting 20 keV boron and phosphorus ions into silicon are reviewed. Special features of theses diodes are presented, and correlation with technology is studied. This paper includes three parts: - in the first part, the theory of range distribution is considered for both amorphous and single-crystal targets, - In the second part, a brief description of the experimental conditions is given. - In the third part, the experimental results are presented. The results lead to a schematic model of the component. They also show the influence of cleaning and annealing treatments from which optimized process of fabrication can be determined. In this study, the influence of a two stage annealing process is shown. For phosphorus and boron implants, the first stage is performed at 150 deg. C while the second stage is 450 deg. C for phosphorus and 550 deg. C for boron implants. The implanted diodes are found to exhibit good electrical characteristics. Comparisons with standard diffused diodes are quite favourable. (author) [French] On examine les caracteristiques de diodes obtenues par implantation d'ions bore et phosphore de 20 keV dans le silicium. On met en evidence le comportement particulier de ces diodes et on presente certaines correlations avec la technologie. L'expose comprend trois parties: - la premiere partie est consacree au calcul du profil de dopage en mode canalise ou non. - Dans la deuxieme partie, on decrit l'appareillage et les conditions experimentales d'implantation. - Dans la troisieme partie, on presente les resultats experimentaux. On propose un modele schematique pour expliquer le comportement des tenues en tension des diodes. L'etude des courants de fuite en fonction de la preparation des echantillons et des traitements thermiques permet de determiner des conditions optimales d'elaboration. Au cours de cette etude on met en evidence l'influence de deux stades de recuit: le premier a 150 deg. C pour les implantations de

The early stages of oxidation of magnesium single crystal surfaces

International Nuclear Information System (INIS)

Hayden, B.E.; Schweizer, E.; Koetz, R.; Bradshaw, A.M.

1981-01-01

The early stages of oxidation of Mg(001) and Mg(100) single crystal surfaces at 300 K have been investigated by LEED, ELS, work function and ellipsometric measurements. A sharp decrease in work function on both surfaces during the first 12 L exposure indicates the incorporation of oxygen in the earliest stages of the interaction. The incorporated oxygen on Mg(001) gives rise to a broadening of the integral order LEED spots for an exposure 3 L. (orig.)

An Implantable Wireless Neural Interface System for Simultaneous Recording and Stimulation of Peripheral Nerve with a Single Cuff Electrode.

Science.gov (United States)

Shon, Ahnsei; Chu, Jun-Uk; Jung, Jiuk; Kim, Hyungmin; Youn, Inchan

2017-12-21

Recently, implantable devices have become widely used in neural prostheses because they eliminate endemic drawbacks of conventional percutaneous neural interface systems. However, there are still several issues to be considered: low-efficiency wireless power transmission; wireless data communication over restricted operating distance with high power consumption; and limited functionality, working either as a neural signal recorder or as a stimulator. To overcome these issues, we suggest a novel implantable wireless neural interface system for simultaneous neural signal recording and stimulation using a single cuff electrode. By using widely available commercial off-the-shelf (COTS) components, an easily reconfigurable implantable wireless neural interface system was implemented into one compact module. The implantable device includes a wireless power consortium (WPC)-compliant power transmission circuit, a medical implant communication service (MICS)-band-based radio link and a cuff-electrode path controller for simultaneous neural signal recording and stimulation. During in vivo experiments with rabbit models, the implantable device successfully recorded and stimulated the tibial and peroneal nerves while communicating with the external device. The proposed system can be modified for various implantable medical devices, especially such as closed-loop control based implantable neural prostheses requiring neural signal recording and stimulation at the same time.

An Implantable Wireless Neural Interface System for Simultaneous Recording and Stimulation of Peripheral Nerve with a Single Cuff Electrode

Directory of Open Access Journals (Sweden)

Ahnsei Shon

2017-12-01

Full Text Available Recently, implantable devices have become widely used in neural prostheses because they eliminate endemic drawbacks of conventional percutaneous neural interface systems. However, there are still several issues to be considered: low-efficiency wireless power transmission; wireless data communication over restricted operating distance with high power consumption; and limited functionality, working either as a neural signal recorder or as a stimulator. To overcome these issues, we suggest a novel implantable wireless neural interface system for simultaneous neural signal recording and stimulation using a single cuff electrode. By using widely available commercial off-the-shelf (COTS components, an easily reconfigurable implantable wireless neural interface system was implemented into one compact module. The implantable device includes a wireless power consortium (WPC-compliant power transmission circuit, a medical implant communication service (MICS-band-based radio link and a cuff-electrode path controller for simultaneous neural signal recording and stimulation. During in vivo experiments with rabbit models, the implantable device successfully recorded and stimulated the tibial and peroneal nerves while communicating with the external device. The proposed system can be modified for various implantable medical devices, especially such as closed-loop control based implantable neural prostheses requiring neural signal recording and stimulation at the same time.

Marginal bone levels at single tooth implants with a conical fixture design. The influence of surface macro- and microstructure.

Science.gov (United States)

Norton, M R

1998-04-01

The concept of a conical implant design to accommodate single tooth replacement, has previously been shown to result in excessive bone loss, around the machined titanium conical collar, usually down to the 1st thread. This unusually aggressive loss of bone was shown to occur within a short period of time, post loading, with greater than 3 mm of bone loss occurring within the 1st 6 months to 1 year. The influence of implant design, surface texture and microleakage have all been highlighted as a potential cause. A modification of the surface structure, both at the macroscopic and microscopic level, as well as an altered fixture-abutment interface design has resulted in the maintenance of marginal bone around a single tooth titanium implant with a similar conical design. The radiographic follow-up of 33 implants loaded for up to 4 years, has revealed, by comparison, a most favourable maintenance of marginal bone around the conical collar, with a mean marginal bone loss of 0.32 mm mesially and 0.34 mm distally for the whole group. The cumulative mean marginal bone loss mesially and distally is 0.42 mm and 0.40 mm from 1 to 2 years, 0.54 mm and 0.43 mm from 2 to 3 years, 0.51 mm and 0.24 mm from 3 to 4 years, and 0.62 mm and 0.60 mm for implants past their 4 year recall.

Analysis of the expression of putatively imprinted genes in bovine peri-implantation embryos

DEFF Research Database (Denmark)

Tveden-Nyborg, Pernille Yde; Alexopoulos, N.I.; Cooney, M.A.

2008-01-01

The application of assisted reproductive technologies (ART) has been shown to induce changes in the methylation of the embryonic genome, leading to aberrant gene expression, including that of imprinted genes. Aberrant methylation and gene expression has been linked to the large offspring syndrome...... (LOS) in bovine embryos resulting in increased embryonic morbidity and mortality. In the bovine, limited numbers of imprinted genes have been studied and studies have primarily been restricted to pre-implantation stages. This study reports original data on the expression pattern of 8 putatively...... imprinted genes (Ata3, Dlk1, Gnas, Grb10, Magel2, Mest-1, Ndn and Sgce) in bovine peri-implantation embryos. Two embryonic developmental stages were examined, Day 14 and Day 21. The gene expression pattern of single embryos was recorded for in vivo, in vitro produced (IVP) and parthenogenetic embryos...

Design of single piece sabot for a single stage gas gun

Science.gov (United States)

Vemparala, Vignesh; Mathew, Arun Tom; Rao Koka, Tirumala

2017-11-01

Single piece sabot is a vital part in single stage gas guns for impact testing in aerospace industries. Depending on the type of projectile used the design of sabot varies to accommodate the testing equipment. The velocity of the projectile exiting the barrel is dependent on the material and shape of the sabot used. The material selected for the design of sabot is rigid polyurethane foam, due to their low elastic modulus and low density. Two samples of rigid PU foam is taken and tests are performed to get their exact material properties. These properties are incorporated in numerical simulation to determine the best fit for practical use. Since the PU foams has a wide range of porosity which plays a prominent role in deciding the exit velocity and accuracy of the projectile coming out of the barrel. By optimisation, to the best suitable material sample can be determined.

Nuclear reaction analysis of Ge ion-implanted ZnO bulk single crystals: The evaluation of the displacement in oxygen lattices

Energy Technology Data Exchange (ETDEWEB)

Kamioka, K.; Oga, T.; Izawa, Y. [College of Engineering and Research Center of Ion Beam Technology, Hosei University, Koganei, Tokyo 184-8584 (Japan); Kuriyama, K., E-mail: kuri@ionbeam.hosei.ac.jp [College of Engineering and Research Center of Ion Beam Technology, Hosei University, Koganei, Tokyo 184-8584 (Japan); Kushida, K. [Department of Arts and Science, Osaka Kyouiku University, Kashiwara, Osaka 582-8582 (Japan); Kinomura, A. [National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan)

2014-08-01

The displacement of oxygen lattices in Ge ion-implanted ZnO bulk single crystals is studied by nuclear reaction analysis (NAR), photoluminescence (PL), and Van der Pauw methods. The Ge ion-implantation (net concentration: 2.6 × 10{sup 20} cm{sup −3}) into ZnO is performed using a multiple-step energy. The high resistivity of ∼10{sup 3} Ω cm in un-implanted samples remarkably decreased to ∼10{sup −2} Ω cm after implanting Ge-ion and annealing subsequently. NRA measurements of as-implanted and annealed samples suggest the existence of the lattice displacement of O atoms acting as acceptor defects. As O related defects still remain after annealing, these defects are not attributed to the origin of the low resistivity in 800 and 1000 °C annealed ZnO.

The Sound Quality of Cochlear Implants: Studies With Single-sided Deaf Patients.

Science.gov (United States)

Dorman, Michael F; Natale, Sarah Cook; Butts, Austin M; Zeitler, Daniel M; Carlson, Matthew L

2017-09-01

The goal of the present study was to assess the sound quality of a cochlear implant for single-sided deaf (SSD) patients fit with a cochlear implant (CI). One of the fundamental, unanswered questions in CI research is "what does an implant sound like?" Conventional CI patients must use the memory of a clean signal, often decades old, to judge the sound quality of their CIs. In contrast, SSD-CI patients can rate the similarity of a clean signal presented to the CI ear and candidate, CI-like signals presented to the ear with normal hearing. For Experiment 1 four types of stimuli were created for presentation to the normal hearing ear: noise vocoded signals, sine vocoded signals, frequency shifted, sine vocoded signals and band-pass filtered, natural speech signals. Listeners rated the similarity of these signals to unmodified signals sent to the CI on a scale of 0 to 10 with 10 being a complete match to the CI signal. For Experiment 2 multitrack signal mixing was used to create natural speech signals that varied along multiple dimensions. In Experiment 1 for eight adult SSD-CI listeners, the best median similarity rating to the sound of the CI for noise vocoded signals was 1.9; for sine vocoded signals 2.9; for frequency upshifted signals, 1.9; and for band pass filtered signals, 5.5. In Experiment 2 for three young listeners, combinations of band pass filtering and spectral smearing lead to ratings of 10. The sound quality of noise and sine vocoders does not generally correspond to the sound quality of cochlear implants fit to SSD patients. Our preliminary conclusion is that natural speech signals that have been muffled to one degree or another by band pass filtering and/or spectral smearing provide a close, but incomplete, match to CI sound quality for some patients.

N+ ion-implantation-induced defects in ZnO studied with a slow positron beam

International Nuclear Information System (INIS)

Chen, Z Q; Sekiguchi, T; Yuan, X L; Maekawa, M; Kawasuso, A

2004-01-01

Undoped ZnO single crystals were implanted with multiple-energy N + ions ranging from 50 to 380 keV with doses from 10 12 to 10 14 cm -2 . Positron annihilation measurements show that vacancy defects are introduced in the implanted layers. The concentration of the vacancy defects increases with increasing ion dose. The annealing behaviour of the defects can be divided into four stages, which correspond to the formation and recovery of large vacancy clusters and the formation and disappearance of vacancy-impurity complexes, respectively. All the implantation-induced defects are removed by annealing at 1200 deg. C. Cathodoluminescence measurements show that the ion-implantation-induced defects act as nonradiative recombination centres to suppress the ultraviolet (UV) emission. After annealing, these defects disappear gradually and the UV emission reappears, which coincides with positron annihilation measurements. Hall measurements reveal that after N + implantation, the ZnO layer still shows n-type conductivity

Nitrite reduction and methanogenesis in a single-stage UASB reactor.

Science.gov (United States)

Borges, L I; López-Vazquez, C M; García, H; van Lier, J B

2015-01-01

In this study, nitrite reduction and methanogenesis in a single-stage upflow anaerobic sludge blanket (UASB) reactor was investigated, using high-strength synthetic domestic wastewater as substrate. To assess long-term effects and evaluate the mechanisms that allow successful nitrite reduction and methanogenesis in a single-stage UASB, sludge was exposed to relatively high nitrite loading rates (315 ± 13 mgNO(2)(-)-N/(l.d)), using a chemical oxygen demand (COD) to nitrogen ratio of 18 gCOD/gNO(2)(-)-N, and an organic loading rate of 5.4 ± 0.2 gCOD/(l.d). In parallel, the effects of sludge morphology on methanogenesis inhibition were studied by performing short-term batch activity tests at different COD/NO(2)(-)-N ratios with anaerobic sludge samples. In long-term tests, denitrification was practically complete and COD removal efficiency did not change significantly after nitrite addition. Furthermore, methane production only decreased by 13%, agreeing with the reducing equivalents requirement for complete NO(2)(-) reduction to N₂. Apparently, the spatial separation of denitrification and methanogenesis zones inside the UASB reactor allowed nitrite reduction and methanogenesis to occur at the same moment. Batch tests showed that granules seem to protect methanogens from nitrite inhibition, probably due to transport limitations. Combined COD and N removal via nitrite in a single-stage UASB reactor could be a feasible technology to treat high-strength domestic wastewater.

Delayed breast implant reconstruction

DEFF Research Database (Denmark)

Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

2011-01-01

the period 1999 to 2006; 239 one-stage procedures and 353 two-stage procedures. The postoperative course through November 2009 was evaluated by cumulative incidence adjusting for competing risks for the selected outcomes; hematoma, infection, seroma, implant rupture, severe capsular contracture (modified...

Influence of two barrier membranes on staged guided bone regeneration and osseointegration of titanium implants in dogs. Part 2: augmentation using bone graft substitutes.

Science.gov (United States)

Mihatovic, Ilja; Becker, Jürgen; Golubovic, Vladimir; Hegewald, Andrea; Schwarz, Frank

2012-03-01

To assess the influence of two barrier membranes and two bone graft substitutes on staged guided bone regeneration and osseointegration of titanium implants in dogs. Saddle-type defects were prepared in the lower jaws of 6 fox hounds and randomly filled with a natural bone mineral (NBM) and a biphasic calcium phosphate (SBC) and allocated to either an in situ gelling polyethylene glycol (PEG) or a collagen membrane (CM). At 8 weeks, modSLA titanium implants were inserted and left to heal in a submerged position. At 8+2 weeks, respectively, dissected blocks were processed for histomorphometrical analysis (e.g., mineralized tissue [MT], bone-to-implant contact [BIC]). The mean MT values (mm2) and BIC values (%) tended to be higher in the PEG groups (MT: NBM [3.4±1.7]; SBC [4.2±2]/BIC: NBM [67.7±16.9]; SBC [66.9±17.8]) when compared with the corresponding CM groups (MT: NBM [2.5±0.8]; SBC [2.3±1.6]/BIC: NBM [54.1±22.6]; SBC [61±8.7]). These differences, however, did not reach statistical significance. It was concluded that all augmentation procedures investigated supported bone regeneration and staged osseointegration of modSLA titanium implants. © 2011 John Wiley & Sons A/S.

Oral Abstract Session 3: Orthognathic/Implants

DEFF Research Database (Denmark)

Hartlev, Jens

Immediate Placement And Provisionalization Of Single-tooth Implants Involving A Final Individual Abutment. A 3-year Clinical And Radiographic Retrospektive Study......Immediate Placement And Provisionalization Of Single-tooth Implants Involving A Final Individual Abutment. A 3-year Clinical And Radiographic Retrospektive Study...

High-Dose-Rate Brachytherapy of a Single Implant With Two Fractions Combined With External Beam Radiotherapy for Hormone-Naive Prostate Cancer

International Nuclear Information System (INIS)

Sato, Morio; Mori, Takashi; Shirai, Shintaro; Kishi, Kazushi; Inagaki, Takeshi; Hara, Isao

2008-01-01

Purpose: To evaluate the preliminary outcomes of high-dose-rate (HDR) brachytherapy of a single implant with two fractions and external beam radiotherapy (EBRT) for hormone-naive prostate cancer. Methods and Materials: Between March 2000 and Sept 2003, a total of 53 patients with tumor Stage T1c-T3b N0 M0 prostate cancer were treated with HDR brachytherapy boost doses (7.5 Gy/fraction) and 50-Gy EBRT during a 5.5-week period. Median follow-up was 61 months. Patients were divided into groups with localized (T1c-T2b) and advanced disease (T3a-T3b). We used the American Society for Therapeutic Radiology and Oncology (ASTRO) definition for biochemical failure. According to recommendations of the Radiation Therapy Oncology Group-ASTRO Phoenix Consensus Conference, biochemical failure-free control rates (BF-FCRs) at 3 years were investigated as 2 years short of the median follow-up. Results: Between April 2000 and Sept 2007, Common Terminology Criteria for Adverse Events Version 2.0 late Grade 2 genitourinary and gastrointestinal toxicity rates were 0% and 3.8%, respectively. Erectile preservation was 25% at 5 years. Overall survival was 88.1% and cause-specific survival was 100%. At 3 years, ASTRO BF-FCRs of the localized and advanced groups were 100% and 42%, respectively (p = 0.001). Conclusions: The HDR brachytherapy of a single implant with two fractions plus EBRT is effective in treating patients with localized hormone-naive prostate cancer, with the least genitourinary and gastrointestinal toxicities; however, longer median BF-FCR follow-up is required to assess these findings

Surface morphologies of He-implanted tungsten

Energy Technology Data Exchange (ETDEWEB)

Bannister, M.E., E-mail: bannisterme@ornl.gov [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6371 (United States); Meyer, F.W.; Hijazi, H. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6371 (United States); Unocic, K.A.; Garrison, L.M.; Parish, C.M. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

2016-09-01

Surface morphologies of tungsten surfaces, both polycrystalline and single-crystal [1 1 0], were investigated using SEM and FIB/SEM techniques after implantations at elevated surfaces temperatures (1200–1300 K) using well-characterized, mono-energetic He ion beams with a wide range of ion energies (218 eV–250 keV). Nanofuzz was observed on polycrystalline tungsten (PCW) following implantation of 100-keV He ions at a flux threshold of 0.9 × 10{sup 16} cm{sup −2} s{sup −1}, but not following 200-keV implantations with similar fluxes. No nanofuzz formation was observed on single-crystal [1 1 0] tungsten (SCW), despite fluxes exceeding those demonstrated previously to produce nanofuzz on polycrystalline tungsten. Pre-damaging the single-crystal tungsten with implanted C impurity interstitials did not significantly affect the surface morphologies resulting from the high-flux He ion implantations. The main factor leading to the different observed surface structures for the pristine and C-implanted single-crystal W samples appeared to be the peak He ion flux characterizing the different exposures. It was speculated that nanofuzz formation was not observed for any SCW target exposures because of increased incubation fluences required for such targets.

Using aided cortical assessment as an objective tool to evaluate cochlear implant fitting in users with single-sided deafness.

Directory of Open Access Journals (Sweden)

Dayse Távora-Vieira

Full Text Available To assess the use of cortical auditory evoked potentials (CAEPs to verify, and if necessary, optimize the cochlear implant (CI fitting of adult CI users with postlingual single-sided deafness (SSD.Sound field cortical responses to the speech tokens /m/, /g/, /t/, and /s/ were recorded from input to the CI while the normal hearing ear was masked. Responses were evaluated by visual inspection and classified as presence or absence of the CAEPs components P1, N1, P2. In case of an absence fitting was adjusted accordingly. After fitting, subjects were asked to use their new setting for 2-3 weeks for acclimatization purposes and then return for retesting. At retesting, new CAEP recordings were performed to objectively ensure that the new fitting maps effectively activated the auditory cortex.In 14/19 subjects, as per visual inspection, clear CAEPs were recorded by each speech token and were, therefore, not refit. In the other 5 subjects, CAEPs could not be evoked for at least one speech token. The fitting maps in these subjects were adjusted until clear CAEPs were evoked for all 4 speech tokens.CAEP can be used to quickly and objectively verify the suitability of CI fitting in experienced adult CI users with SSD. If used in the early post-implantation stage, this method could help CI users derive greater benefit for CI use and, therefore, be more committed to auditory training.

Renal Function and Outcomes With Use of Left Ventricular Assist Device Implantation and Inotropes in End-Stage Heart Failure: A Retrospective Single Center Study.

Science.gov (United States)

Verma, Sean; Bassily, Emmanuel; Leighton, Shane; Mhaskar, Rahul; Sunjic, Igor; Martin, Angel; Rihana, Nancy; Jarmi, Tambi; Bassil, Claude

2017-07-01

Left ventricular assist device (LVAD) and inotrope therapy serve as a bridge to transplant (BTT) or as destination therapy in patients who are not heart transplant candidates. End-stage heart failure patients often have impaired renal function, and renal outcomes after LVAD therapy versus inotrope therapy have not been evaluated. In this study, 169 patients with continuous flow LVAD therapy and 20 patients with continuous intravenous inotrope therapy were analyzed. The two groups were evaluated at baseline and at 3 and 6 months after LVAD or inotrope therapy was started. The incidence of acute kidney injury (AKI), need for renal replacement therapy (RRT), BTT rate, and mortality for 6 months following LVAD or inotrope therapy were studied. Results between the groups were compared using Mann-Whitney U test and Chi-square with continuity correction or Fischer's exact at the significance level of 0.05. Mean glomerular filtration rate (GFR) was not statistically different between the two groups, with P = 0.471, 0.429, and 0.847 at baseline, 3 and 6 months, respectively. The incidence of AKI, RRT, and BTT was not statistically different. Mortality was less in the inotrope group (P < 0.001). Intravenous inotrope therapy in end-stage heart failure patients is non-inferior for mortality, incidence of AKI, need for RRT, and renal function for 6-month follow-up when compared to LVAD therapy. Further studies are needed to compare the effectiveness of inotropes versus LVAD implantation on renal function and outcomes over a longer time period.

Procedure times, complication rates, and survival times associated with single-chamber versus dual-chamber pacemaker implantation in dogs with clinical signs of bradyarrhythmia: 54 cases (2004-2009).

Science.gov (United States)

Genovese, David W; Estrada, Amara H; Maisenbacher, Herbert W; Heatwole, Bonnie A; Powell, Melanie A

2013-01-15

To compare procedure times and major and minor complication rates associated with single-chamber versus dual-chamber pacemaker implantation and with 1-lead, 2-lead, and 3-lead pacemaker implantation in dogs with clinical signs of bradyarrhythmia. Retrospective case series. 54 dogs that underwent pacemaker implantation because of clinical signs of bradyarrhythmia. Medical records of dogs that received pacemakers between July 2004 and December 2009 were reviewed for information regarding signalment, diagnosis, pacemaker implantation, pacemaker type, complications, and survival time. Analyses were performed to determine significant differences in anesthesia time, procedure time, and outcome for dogs on the basis of pacing mode and number of pacing leads. 28 of 54 (51.9%) dogs received single-chamber pacemakers and 26 (48.1%) received dual-chamber pacemakers. Mean ± SD procedural time was significantly longer for patients with dual-chamber pacemakers (133.5 ± 51.3 minutes) than for patients with single-chamber pacemakers (94.9 ± 37.0 minutes), and procedure time increased significantly as the number of leads increased (1 lead, 102.3 ± 51.1 minutes; 2 leads, 114.9 ± 24.8 minutes; 3 leads, 158.2 ± 8.5 minutes). Rates of major and minor complications were not significantly different between dogs that received single-chamber pacemakers and those that received dual-chamber pacemakers or among dogs grouped on the basis of the number of pacing leads placed. Although dual-chamber pacemaker implantation did result in increased procedural and anesthesia times, compared with single-chamber pacemaker implantation, this did not result in a higher complication rate.

Clinical evaluation of a novel dental implant system as single implants under immediate loading conditions - 4-month post-loading results from a multicentre randomised controlled trial.

Science.gov (United States)

Esposito, Marco; Trullenque-Eriksson, Anna; Blasone, Rodolfo; Malaguti, Giuliano; Gaffuri, Cristiano; Caneva, Marco; Minciarelli, Armando; Luongo, Giuseppe

To evaluate the safety and clinical effectiveness of a novel dental implant system (GENESIS Implant System, Keystone Dental, Massachusetts, USA) using another dental implant system by the same manufacturer as a control (PRIMA Implant System, Keystone Dental). A total of 53 patients requiring at least two single crowns had their sites randomised according to a split-mouth design to receive both implant systems at six centres. If implants could be placed with a torque superior to 40 Ncm they were to be loaded immediately with provisional crowns, otherwise after 3 months of submerged healing. Provisional crowns were replaced by definitive crowns 4 months after initial loading, when the follow-up period for the initial part of this study was completed. Outcome measures were crown/implant failures, complications, pink esthetic score (PES), peri-implant marginal bone level changes, plaque score, marginal bleeding, patients and preference of the clinician. In total 53 PRIMA and 53 GENESIS implants were placed. Three patients dropped out but all of the remaining patients were followed up to 4-months post-loading. No PRIMA implant failed whereas four GENESIS implants failed. Only two complications were reported for PRIMA implants. There were no statistically significant differences for crown/implant failures (difference in proportions = 0.080; P (McNemar test) = 0.125) and complications (difference in proportions = -0.04; P (McNemar test) = 0.500) between the implant systems. There were no differences at 4-months post-loading for plaque (difference = -0.54, 95% CI: -3.01 to 1.93; P (Paired t-test) = 0.660), marginal bleeding (difference = -3.8, 95% CI: -7.63 to 0.019; P (Paired t-test) = 0.051), PES (difference = 0.47, 95% CI: -0.56 to 1.50; P (Paired t-test) = 0.365) and marginal bone level changes (difference in mm = -0.04, 95% CI: -0.33 to 0.26; P (Paired t-test) = 0.795). The majority of the patients (46) had no

Comparison of single and mixed ion implantation effects on the changes of the surface hardness, light transmittance, and electrical conductivity of polymeric materials

International Nuclear Information System (INIS)

Park, J. W.; Lee, J. H.; Lee, J. S.; Kil, J. G.; Choi, B. H.; Han, Z. H.

2001-01-01

Single or mixed ions of N, He, C were implanted onto the transparent PET(Polyethylen Terephtalate) with the ion energies of less than 100 keV and the surface hardness, light transmittance and electrical conductivity were examined. As measured with nanoindentation, mixed ion implantations such as N + +He + or N + + C + exhibited more increase in the surface hardness than the single ion implantation. Especially, implantation of C+N ions increased the surface hardness by about three times as compared to the implantation of N ion alone, which means more than 10 times increase than the untreated PET. Surface electrical conductivity was increased along with the hardness increase. The conductivity increase was more proportional to the hardness when used the higher ion energy and ion dose, while it did not show any relationship at as low as 50 keV of ion energy. The light at the 550 nm wavelength (visual range) transmitted more than 85%, which is close to that of as-received PET, and at the wavelength below 300 nm(UV range) the rays were absorbed more than 95% as traveling through the sheet, implying that there are processing parameters which the ion implanted PET maintains the transparency and absorbs the UV rays

Optimization of dental implantation

Science.gov (United States)

Dol, Aleksandr V.; Ivanov, Dmitriy V.

2017-02-01

Modern dentistry can not exist without dental implantation. This work is devoted to study of the "bone-implant" system and to optimization of dental prostheses installation. Modern non-invasive methods such as MRI an 3D-scanning as well as numerical calculations and 3D-prototyping allow to optimize all of stages of dental prosthetics. An integrated approach to the planning of implant surgery can significantly reduce the risk of complications in the first few days after treatment, and throughout the period of operation of the prosthesis.

N{sup +} ion-implantation-induced defects in ZnO studied with a slow positron beam

Energy Technology Data Exchange (ETDEWEB)

Chen, Z Q [Japan Atomic Energy Research Institute, 1233 Watanuki, Takasaki, Gunma 370-1292, Japan (Japan); Sekiguchi, T [Nanomaterials Laboratory, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Yuan, X L [Nanomaterials Laboratory, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Maekawa, M [Japan Atomic Energy Research Institute, 1233 Watanuki, Takasaki, Gunma 370-1292, Japan (Japan); Kawasuso, A [Japan Atomic Energy Research Institute, 1233 Watanuki, Takasaki, Gunma 370-1292, Japan (Japan)

2004-01-21

Undoped ZnO single crystals were implanted with multiple-energy N{sup +} ions ranging from 50 to 380 keV with doses from 10{sup 12} to 10{sup 14} cm{sup -2}. Positron annihilation measurements show that vacancy defects are introduced in the implanted layers. The concentration of the vacancy defects increases with increasing ion dose. The annealing behaviour of the defects can be divided into four stages, which correspond to the formation and recovery of large vacancy clusters and the formation and disappearance of vacancy-impurity complexes, respectively. All the implantation-induced defects are removed by annealing at 1200 deg. C. Cathodoluminescence measurements show that the ion-implantation-induced defects act as nonradiative recombination centres to suppress the ultraviolet (UV) emission. After annealing, these defects disappear gradually and the UV emission reappears, which coincides with positron annihilation measurements. Hall measurements reveal that after N{sup +} implantation, the ZnO layer still shows n-type conductivity.

NOFBX Single-Stage-to-Orbit Mars Ascent Vehicle Engine, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — We propose the continuation of our research and development of a Nitrous Oxide Fuel Blend (NOFBXTM) Single-Stage-to-Orbit (SSTO) monopropellant propulsion system for...

Single Sitting Surgical Treatment of Generalized Aggressive Periodontitis Using GTR Technique and Immediate Implant Placement with 10-Year Follow-Up

Directory of Open Access Journals (Sweden)

Fatme Mouchref Hamasni

2018-01-01

Full Text Available This case report exhibits a patient with generalized aggressive periodontitis who has been under maintenance for the past 12 years after being surgically treated in a single sitting and restored with dental implants. A 41-year-old systemically healthy male patient presented complaining of lower anterior teeth mobility and pain in the upper right quadrant. After clinical and radiographic examination, the upper right molars and lower anterior incisors were deemed unrestorable. Covered by doxycycline, the patient received a nonsurgical periodontal treatment. Three weeks later, teeth extraction, immediate implant placement, immediate nonloading provisional prosthesis, and a guided tissue regeneration were performed at indicated areas in a single sitting. The clinical decisions were based on patient compliance, the status of the existing periodontal tissues, and the prognosis of the remaining teeth. During the 12-year follow-up period, no residual pockets were observed and there was no exacerbation of the inflammatory condition. Marginal bone stability is present on all implants. For aggressive periodontal disease, a high risk of relapse as well as limited success and survival of dental implants should be considered. This case shows proper containment of the disease based on appropriate treatment planning and a strict maintenance program.

Clinical Outcome of Inter-Proximal Papilla between a Tooth and a Single Implant Treated with CAD/CAM Abutments: a Cross-Sectional Study

Directory of Open Access Journals (Sweden)

Tiago Borges

2012-09-01

Full Text Available Objectives: The aim of this study was to assess the clinical outcomes achieved with Computer-Assisted Design/Computer-Assisted Manufacturing implant abutments in the anterior maxilla.Material and Methods: Nineteen patients with a mean age of 41 (range form 26 to 63 years, treated with 21 single tooth implants and 21 Computer-Assisted Design/Computer-Assisted Manufacturing (CAD/CAM abutments in the anterior maxillary region were included in this study. The patients followed 4 criteria of inclusion: (1 had a single-tooth implant in the anterior maxilla, (2 had a CAD/CAM abutment, (3 had a contralateral natural tooth, (4 the implant was restored and in function for at least 6 months up to 2 years. Cases without contact point were excluded. Presence/absence of the interproximal papilla, inter tooth-implant distance (ITD and distance from the base of the contact point to dental crest bone of adjacent tooth (CPB were accessed. Results: Forty interproximal spaces were evaluated, with an average mesial CPB of 5.65 (SD 1.65 mm and distal CPB of 4.65 (SD 1.98 mm. An average mesial ITD of 2.49 (SD 0.69 mm and an average distal ITD of 1.89 (SD 0.63 mm were achieved. Papilla was present in all the interproximal spaces accessed. Conclusions: The restoration of dental implants using CAD/CAM abutments is a predictable treatment with improved aesthetic results. These type of abutments seem to help maintaining a regular papillary filling although the variations of the implant positioning or the restoration teeth relation.

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.

Single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation in surgical treatment for single-segment lumbar spinal tuberculosis

OpenAIRE

Zeng, Hao; Wang, Xiyang; Zhang, Penghui; Peng, Wei; Zhang, Yupeng; Liu, Zheng

2015-01-01

Objective: The aim of this study is to determine the feasibility and efficacy of surgical management of single-segment lumbar spinal tuberculosis (TB) by using single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation.Methods: Seventeen cases of single-segment lumbar TB were treated with single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reco...

Electric field dependent paramagnetic defect creation in single step implanted Simox films

International Nuclear Information System (INIS)

Leray, J.L.; Margail, J.

1991-01-01

X irradiation induced oxygen-vacancy defect creation has been studied in SIMOX produced by single step implantation and annealing. It is shown that SIMOX is substantially more radiation sensitive (for these defects) than thermal or bulk oxide. Irradiation in the presence of an electric field 0.5 -1 MV cm -1 is found to enhance the rate of defect creation by ≥ 2 times. Further enhanced defect creation is observed in SIMOX samples whose substrate has been chemically thinned prior to irradiation. This enhancement is attributed to modification of the network induced by hydrogen introduced during the thinning process

Practical Considerations Concerning the Interleaved Transition Mode Single-stage Ballast

DEFF Research Database (Denmark)

Teodorescu, Remus; Kjær, Søren Bækhøj; Munk-Nielsen, Stig

2002-01-01

The aim of this paper is to present a novel single-stage interleaved ballast focusing on practical design aspects like: key current expression, overall losses, harmonic analysis of the differential-mode EMI current and preheating ballast function. A new preheating method is also presented. A PSPICE...

A portable high-power diode laser-based single-stage ceramic tile grout sealing system

Science.gov (United States)

Lawrence, J.; Schmidt, M. J. J.; Li, L.; Edwards, R. E.; Gale, A. W.

2002-02-01

By means of a 60 W high-power diode laser (HPDL) and a specially developed grout material the void between adjoining ceramic tiles has been successfully sealed. A single-stage process has been developed which uses a crushed ceramic tile mix to act as a tough, inexpensive bulk substrate and a glazed enamel surface to provide an impervious surface glaze. The single-stage ceramic tile grout sealing process yielded seals produced in normal atmospheric conditions that displayed no discernible cracks and porosities. The single-stage grout is simple to formulate and easy to apply. Tiles were successfully sealed with power densities as low as 200 kW/ mm2 and at rates of up to 600 mm/ min. Bonding of the enamel to the crushed ceramic tile mix was identified as being primarily due to van der Waals forces and, on a very small scale, some of the crushed ceramic tile mix material dissolving into the glaze. In terms of mechanical, physical and chemical characteristics, the single-stage ceramic tile grout was found to be far superior to the conventional epoxy tile grout and, in many instances, matched and occasionally surpassed that of the ceramic tiles themselves. What is more, the development of a hand-held HPDL beam delivery unit and the related procedures necessary to lead to the commercialisation of the single-stage ceramic tile grout sealing process are presented. Further, an appraisal of the potential hazards associated with the use of the HPDL in an industrial environment and the solutions implemented to ensure that the system complies with the relevant safety standards are given.

Carrier transfer and magneto-transport in single modulation-doped V-grooved quantum wire modified by ion implantation

International Nuclear Information System (INIS)

Huang, S.H.; Chen Zhanghai; Wang, F.Z.; Shen, S.C.; Tan, H.H.; Fu, L.; Fraser, M.; Jagadish, C.

2006-01-01

A single Al 0.5 Ga 0.5 As/GaAs V-grooved quantum wire modified by selective ion implantation and rapid thermal annealing was investigated by using spatially resolved micro-photoluminescence spectroscopy and magneto-resistance measurements. The results of spatially resolved photoluminescence indicate that the ion-implantation-induced quantum well intermixing significantly raises the electronic sub-band energies in the side quantum wells (SQWs) and vertical quantum wells, and a more efficient accumulation of electrons in the quantum wires is achieved. Processes of real space carrier transfer from the SQW to the quantum wire was experimentally observed, and showed the blocking effect of carrier transfer due to the existence of the necking quantum well region. Furthermore, magneto-transport investigation on the ion-implanted quantum wire samples shows the quasi-one-dimensional intrinsic motion of electrons, which is important for the design and the optimization of one-dimensional electronic devices

Single-staged uniportal VATS in the supine position for simultaneous bilateral primary spontaneous pneumothorax.

Science.gov (United States)

Kim, Kyung Soo

2017-05-15

Simultaneous bilateral primary spontaneous pneumothorax (SBPSP) is rare, but requires surgery on both sides, in patients with definite bilateral bullae to prevent life-threatening conditions. Recently, uniportal video-assisted thoracoscopic surgery (VATS) has been widely accepted as a less invasive technique for the treatment of pneumothorax. Thus, we introduced single-staged uniportal VATS technique in the supine position, for the management of two cases of SBPSP. A 17-year-old boy presented with bilateral spontaneous pneumothorax and he underwent single-staged uniportal VATS in the supine position. Single wide draping in consecutive bilateral approaches removes the needs of changing patients' position. Whole thoracoscopic procedure for wedge resection of bullae lesions was conducted without difficulty. The total operation time took 65 min and the patient discharged 3 days after the operation. The patient was followed for 24 months without recurrence of both sides. Another 18-year-old boy was admitted with bilateral spontaneous pneumothorax and single-staged uniportal VATS was also performed in the supine position. The total operation time took 79 min and the patient discharged on postoperative day 4. He was followed for 19 months without recurrence of both sides. Single-staged uniportal VATS approach yielded satisfactory results from simplicity that not requires position change compared to conventional multi-ports VATS in the lateral position, and with better cosmetics. This technique is thought to be a feasible procedure in selective patients with SBPSP or with contralateral bullae for preventive role.

Clinical evaluation of the stability of implants placed at different supracrestal levels.

Science.gov (United States)

Gultekin, B Alper; Sirali, Ali; Gultekin, Pinar; Ersanli, Selim

2016-01-01

The aim of this study was to evaluate the stability during healing and before loading of implants placed at two different supracrestal levels according to their collar texture. This retrospective study included patients who received posterior implants with the same macro design. Implants with a machined collar were placed 0.3 mm above the crestal bone (M group), while those with a laser-microtextured collar were placed 1 mm above the crestal bone (L group). All implants healed in a single stage with healing abutments. Implant stability quotient (ISQ) values were determined using resonance frequency analysis immediately after implant placement during surgery and after 1, 4, 8, and 12 weeks after surgery. Other evaluated factors for stability included the implant diameter and length and the site of placement (maxilla or mandible). In total, 103 implants (47 L, 56 M) were evaluated. The median ISQ values at baseline and 1 week after placement were significantly higher for the M group than for the L group (p=0.006 and p=0.031, respectively). There were no differences at the subsequent observation points. The ISQ value was higher for wide-diameter than regular diameter (p=0.001) and mandibular implants than maxillary implants (p=0.001 at 0-8. weeks; p=0.012 at 12 weeks) at all observation points. When diameter data were neglected, the implant length did not influence the ISQ value at all observation points. Our results suggest that submerging implant more inside bone may only influence primary stability. Moreover, the implant diameter and site of placement influence primary and secondary stability before loading, whereas the implant length does not when its diameter is not accounted for.

Endoscope-Assisted and Controlled Argus II Epiretinal Prosthesis Implantation in Late-Stage Retinitis Pigmentosa: A Report of 2 Cases.

Science.gov (United States)

Özmert, Emin; Demirel, Sibel

2016-01-01

Several different approaches for restoring sight in subjects who are blind due to outer retinal degeneration are currently under investigation, including stem cell therapy, gene therapy, and visual prostheses. Although many different types of visual prostheses have shown promise, to date, the Argus II Epiretinal Prosthesis System, developed in a clinical setting over the course of 10 years, is the world's first and only retinal prosthesis that has been approved by the United States Food and Drug Administration (FDA) and has been given the CE-Mark for sale within the European Economic Area (EEA). The incidence of serious adverse events from Argus II implantation decreased over time after minor changes in the implant design and improvements in the surgical steps used for the procedure had been made. In order to further decrease the scleral incision-related complications and enhance the assessment of the tack position and the contact between the array and the inner macular surface, we used an ophthalmic endoscope during the regular course of Argus II implantation surgery in 2 patients with late-stage retinitis pigmentosa in an attempt to improve the anatomical and functional outcomes.

Endoscope-Assisted and Controlled Argus II Epiretinal Prosthesis Implantation in Late-Stage Retinitis Pigmentosa: A Report of 2 Cases

Directory of Open Access Journals (Sweden)

Emin Özmert

2016-12-01

Full Text Available Several different approaches for restoring sight in subjects who are blind due to outer retinal degeneration are currently under investigation, including stem cell therapy, gene therapy, and visual prostheses. Although many different types of visual prostheses have shown promise, to date, the Argus II Epiretinal Prosthesis System, developed in a clinical setting over the course of 10 years, is the world’s first and only retinal prosthesis that has been approved by the United States Food and Drug Administration (FDA and has been given the CE-Mark for sale within the European Economic Area (EEA. The incidence of serious adverse events from Argus II implantation decreased over time after minor changes in the implant design and improvements in the surgical steps used for the procedure had been made. In order to further decrease the scleral incision-related complications and enhance the assessment of the tack position and the contact between the array and the inner macular surface, we used an ophthalmic endoscope during the regular course of Argus II implantation surgery in 2 patients with late-stage retinitis pigmentosa in an attempt to improve the anatomical and functional outcomes.

Properties and local environment of p-type and photoluminescent rare earths implanted into ZnO single crystals

CERN Document Server

Rita, EMC; Wahl, U; Soares, JC

This thesis presents an experimental study of the local environment of p-type and Rare- Earth dopants implanted in ZnO single-crystals (SCs). Various nuclear and bulk property techniques were combined in the following evaluations: Implantation damage annealing was evaluated in ZnO SCs implanted with Fe, Sr and Ca. P-type dopants Cu and Ag implanted ZnO SCs were studied revealing that the solubility of Cu in substituting Zn is considerably higher than that of Ag. These results are discussed within the scope of the ZnO p-type doping problematic with these elements. Experimental proofs of the As “anti-site” behavior in ZnO were for the first time attained, i.e., the majority of As atoms are substitutional at the Zn site (SZn), possibly surrounded by two Zn vacancies (VZn). This reinforces the theoretical prediction that As acts as an acceptor in ZnO via the AsZn-2VZn complex formation. The co-doping of ZnO SC with In (donor) and As (acceptor) was addressed. The most striking result is the possible In-As “p...

Surgical reconstruction of pressure ulcer defects: a single- or two-stage procedure?

LENUS (Irish Health Repository)

Laing, Tereze A

2012-02-01

BACKGROUND: The surgical management of pressure ulcers traditionally involved staged procedures, with initial debridement of necrotic or infected material followed by reconstruction at a later date when the wound was deemed viable and free of gross infection. However, over the past decade, it has been suggested that a single-stage procedure, combining initial debridement and definitive reconstruction, may provide advantages over staged surgery. We present our experience with the staged approach and review the current evidence for both methods. SUBJECTS AND SETTINGS: : We reviewed medical records of all patients referred to our service for pressure ulcer management between October 2001 and October 2007. The National Rehabilitation Hospital is the national center in Ireland for primary rehabilitation of adults and children suffering from spinal and brain injury, serving patients locally and from around the country. METHODS: All subjects who were managed surgically underwent a 2-stage procedure, with initial debridement and subsequent reconstruction. The main outcome measures were length of hospital stay, postoperative morbidity and mortality, and time to complete ulcer healing. RESULTS: Forty-one of 108 patients with 58 pressure ulcers were managed surgically. All patients underwent initial surgical debridement and 20 patients underwent subsequent pressure ulcer reconstruction. Postreconstructive complications occurred in 5 patients (20%). The mean time to complete ulcer healing was 17.4 weeks. Partial flap necrosis occurred in 3 patients, but there were no episodes of flap failure. CONCLUSIONS: We achieved favorable results with a 2-stage reconstruction technique and suggest that the paucity of evidence related to single-stage procedures does not support a change in surgical management.

Effects of Appropriate Prolonged Sacral Neuromodulation Testing in Improving Implantation Rate of a Permanent Implantable Pulse Generator in Patients with Refractory Lower Urinary Tract Dysfunctions in Mainland China

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Peng Zhang

2017-01-01

Results: Among 51 patients receiving SNM therapy, 19 patients (mean age 45.0 ± 16.9 years had poor Stage I test results, and on an average, the electrode was removed 27.4 ± 9.6 days after the surgery. In one patient, the electrode was removed within 2 weeks; when the remaining 18 patients were questioned 2 weeks after testing, none of the patients wanted to terminate the test, and all the 18 patients desired to prolong the testing time to further observe the treatment effect. The remaining 32 patients (mean age 46.7 ± 15.3 years received Stage II permanent implantation at 19.6 ± 10.4 days after the surgery. The overall Stage I–II conversion was 62.7% (32/51 in this study. Within 2 weeks after the surgery, only eight patients received Stage II permanent implantation, and the conversion rate was only 15.7% (8/51, which was much lower than the overall conversion rate of 62.7%. Nearly 84.4% (27/32 of the patients received Stage II implantation within 4 weeks. None of the patients had incision infections. In one patient, the entire system was removed 1 month after Stage II implantation due to pain in the implantation site. Conclusions: Appropriate extension of the Stage I testing time of an SNM-barbed electrode could significantly improve the Stage II permanent implantation rate in Chinese refractory LUTS patients; there were no wound infections, and the postoperative complication rate was low. This study recommended that Stage I period of SNM therapy should be 4 weeks according to safety and successful conversion rate.

Survival rates and bone loss after immediate loading of implants in fresh extraction sockets (single gaps). A clinical prospective study with 4 year follow-up

Science.gov (United States)

Wojtovicz, Eduardo; España-Lopez, Antonio; Jimenez-Guerra, Alvaro; Monsalve-Guil, Loreto; Ortiz-Garcia, Ivan; Serrera-Figallo, Maria-Angeles

2018-01-01

Background The aim of this prospective study was to report the outcome of treatment with implants inserted after tooth extraction and immediately loaded. Material and Methods Fifty-six patients with single tooth loss were treated with 116 IPX Galimplant® implants with internal connections and a sandblasted, acid-etched surface. All implants were placed after tooth extraction using a flapless approach without bone regeneration, and they were then immediately loaded with cemented acrylic prostheses. After a period of three months, definitive cemented ceramic prostheses were placed. Patients were examined throughout a total of 4 years of follow-up. Marginal bone loss and survival rates were evaluated using digital periapical radiographs, taking into account clinical variables such as age, gender, smoking, history of periodontitis, etiology of extraction, placement site, diameter, and implant length. The Mann-Whitney U and Kruskal-Wallis non-parametric tests were used to compare differences between subgroups created based on the different clinical variables identified. Results Clinical results indicate an implant survival and success rate of 97.4%. Three implants were lost. Of the 116 immediate acrylic single crowns initially placed, 113 were replaced with definitive ceramic crowns after 3 months. A total of 77.8% of implants were inserted in the maxilla, while 22.2% were inserted in the mandible. No further complications were reported after the follow-up period (4 years). The mean marginal bone loss was 0.67 mm ± 0.40 mm. No differences were found among the subgroups of study patients. Conclusions This study indicates that dental implants that are inserted after tooth extraction and immediately loaded may constitute a successful and predictable alternative implant treatment. Key words:Dental implants, post-extraction implants, fresh sockets, immediate loading, immediate prostheses, implant dentistry. PMID:29476669

Finite Element Analysis of Bone Stress around Micro-Implants of Different Diameters and Lengths with Application of a Single or Composite Torque Force.

Science.gov (United States)

Lu, Ying-juan; Chang, Shao-hai; Ye, Jian-tao; Ye, Yu-shan; Yu, Yan-song

2015-01-01

Stress on the bone surrounding dental micro-implants affects implant success. To compare the stress on the bone surrounding a micro-implant after application of a single force (SF) of 200 g or a composite force (CF) of 200 g and 6 N.mm torque. Finite element models were developed for micro-implant diameters of 1.2, 1.6, and 2.0 mm, and lengths of 6, 8, 10, and 12 mm and either a SF or CF was applied. The maximum equivalent stress (Max EQS) of the bone surrounding the micro-implant was determined, and the relationships among type of force, diameter, and length were evaluated. The Max EQS of the CF exceeded that of the SF (Pimplant diameter, but not to implant length. The larger CF led to greater instability of the micro-implant and the effect was most pronounced at an implant diameter of 1.2 mm. The use of implant diameters of 1.6 mm and 2.0 mm produced no significant difference in implant stability when either a CF or SF was applied. When considering the use of an implant to perform three-dimensional control on the teeth, the implant diameter chosen should be > 1.2 mm.

Implantable cardioverter defibrillator therapy in pediatric and congenital heart disease patients: a single tertiary center experience in Korea

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Bo Kyung Jin

2013-03-01

Full Text Available Purpose: The use of implantable cardioverter defibrillators (ICDs to prevent sudden cardiac death is increasing in children and adolescents. This study investigated the use of ICDs in children with congenital heart disease. Methods: This retrospective study was conducted on the clinical characteristics and effectiveness of ICD implantation at the department of pediatrics of a single tertiary center between 2007 and 2011. Results: Fifteen patients underwent ICD implantation. Their mean age at the time of implantation was 14.5±5.4 years (range, 2 to 22 years. The follow-up duration was 28.9±20.4 months. The cause of ICD implantation was cardiac arrest in 7, sustained ventricular tachycardia in 6, and syncope in 2 patients. The underlying disorders were as follows: ionic channelopathy in 6 patients (long QT type 3 in 4, catecholaminergic polymorphic ventricular tachycardia [CPVT] in 1, and J wave syndrome in 1, cardiomyopathy in 5 patients, and postoperative congenital heart disease in 4 patients. ICD coils were implanted in the pericardial space in 2 children (ages 2 and 6 years. Five patients received appropriate ICD shock therapy, and 2 patients received inappropriate shocks due to supraventricular tachycardia.During follow-up, 2 patients required lead dysfunction-related revision. One patient with CPVT suffered from an ICD storm that was resolved using sympathetic denervation surgery. Conclusion: The overall ICD outcome was acceptable in most pediatric patients. Early diagnosis and timely ICD implantation are recommended for preventing sudden death in high-risk children and patients with congenital heart disease.

[Trabeculotomy ab interno combined with extracapsular cataract extraction and IOL implantation].

Science.gov (United States)

Alekseev, B N; Ermolaev, A P

2003-01-01

We made a total of 96 surgeries of extracapsular cataract extraction and IOL implantation combined with trabeculotomy ab interno during a period of 7 years. Patients with both open-angle and narrow-angle glaucoma of stages I and II and with the intraocular pressure (IOP) below or equal to 23 mm Hg according to Goldman under the conditions of hypotensive medicamental regimen were selected for surgery. After IOL was implanted into the lens bag, trabeculotomy ab interno was implemented as stage 2. A special mirror, introduced through the cataract incision, was used for direct gonioscopic monitoring. The trabecula was incised by the edge of a curved surgical knife under direct visual control. We regarded bleeding from the opened sinus as a favorable sign indicative of that the intrascleral collectors were intact. Only minor hyphemas were registered as postoperative complications; there was not a single case of ciliary-and-choroidal detachment. IOP was compensated for, in 6 months after surgery, in 94% of patients--69.8% of them did not use any hypotensive drops.

Post procedural complications of cardiac implants done in a resource limited setting under 'C' arm: A single centre experience.

Science.gov (United States)

Jayachandra, A; Aggarwal, Vivek; Kumar, Sandeep; Nagesh, I V

2018-04-01

Cardiology interventions in peripheral hospitals is a challenging task where cardiologist have to fight against time and limited resources. Most of the sudden cardiac deaths occur due to arrhythmia and heart blocks/sinus node dysfunction. Our study is a single peripheral center experience of cardiac devices implantation using a 'C' Arm. The aim of this study was to post procedural complications of cardiac implants done in aresource limited setting under 'C' arm. This study is done at a peripheral cardiology center with no cardiac catheterization laboratory (CCL) facilities. Consecutive patients reporting to cardiology center, between Jan 2015 and Oct 2016, with a definite indication for cardiac device implant were included in the study. All the procedure of implantation was done in the operation theatre under 'C' arm under local anesthesia with continuous cardiac monitoring and critical care back up. Total 58 device implantations were done from Jan 2015 to Oct 2016. The mean age of the patients was 67.15 ± 10.85 years. Males constituted almost two third (68.9%) of patients. The commonest indication for device implantation was sinus node dysfunction in 60.34% followed by complete heart block in 25.86% and ventricular tachycardia in 12.06%. No post procedure infection was observed in our study. Device implantation constitute a major group of life saving interventions in cardiology practice. Our study has emphasised that when appropriate aseptic measures are taken during device implantation at peripheral centres, the complications rate are comparable to interventions done at advance cardiac centres.

Successful Rehabilitation of Partial Edentulous Maxilla and Mandible with New Type of Implants: Molecular Precision Implants

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Matteo Danza

2014-01-01

Full Text Available The extraction of teeth results in rapid bone resorption both vertically and horizontally in the first month. The loss of alveolar ridge reduces the chance of implant rehabilitation. Atraumatic extraction, implant placement in extraction socket, and an immediate prosthesis have been proposed as alternative therapies to maintain the volume and contours tissue and reduce time and cost of treatment. The immediate load of implants is a universally practiced procedure; nevertheless a successful procedure requires expertise in both the clinical and the reconstructive stages using a solid implant system. Excellent primary stability and high bone-implant contact are only minimal requirements for any type of implant procedure. In this paper we present a case report using a new type of implants. The new type of implants, due to its sophisticated control system of production, provides to the implantologist a safe and reliable implant, with a macromorphology designed to ensure a close contact with the surrounding bone.

Evaluation of Geometrically Optimized Single- and Double-plane Interstitial High Dose Rate Implants with Respect to Conformality and Homogeneity

International Nuclear Information System (INIS)

Major, Tibor; Polgar, Csaba; Fodor, Janos; Takacsi-nagy, Zoltan; Mangel, Laszlo; Nemeth, Gyoergy

2003-01-01

The use of a stepping source in high dose rate brachytherapy supported with dwell-time optimization makes it possible to deviate from the classical dosimetry systems. Dose distributions of single- and double-plane implants were analysed for conformality and homogeneity at idealized target volumes. The Paris system was used for catheter positioning and target volume determination. Geometric optimization and individual dose prescription were applied. Volumetric indices and dose parameters were calculated at optimal active length, which was found to be equal to target volume length. The mean conformality, homogeneity, external volume and overdose volume indices were 0.78, 0.67, 0.22 and 0.13, respectively. The average minimum target and reference doses were 69% and 86%, respectively. Comparisons between the volumetric indices of geometrical optimized and non-optimized implants were also performed, and a significant difference was found regarding any index. The geometrical optimization resulted in superior conformality and slightly inferior homogeneity. At geometrically optimized implants, the active length can be reduced compared to non-optimized implants. Volumetric parameters and dose-volume histogram-based individual dose prescription are recommended for quantitative assessment of interstitial implants

Digital versus analog complete-arch impressions for single-unit premolar implant crowns: Operating time and patient preference.

Science.gov (United States)

Schepke, Ulf; Meijer, Henny J A; Kerdijk, Wouter; Cune, Marco S

2015-09-01

Digital impression-making techniques are supposedly more patient friendly and less time-consuming than analog techniques, but evidence is lacking to substantiate this assumption. The purpose of this in vivo within-subject comparison study was to examine patient perception and time consumption for 2 complete-arch impression-making methods: a digital and an analog technique. Fifty participants with a single missing premolar were included. Treatment consisted of implant therapy. Three months after implant placement, complete-arch digital (Cerec Omnicam; Sirona) and analog impressions (semi-individual tray, Impregum; 3M ESPE) were made, and the participant's opinion was evaluated with a standard questionnaire addressing several domains (inconvenience, shortness of breath, fear of repeating the impression, and feelings of helplessness during the procedure) with the visual analog scale. All participants were asked which procedure they preferred. Operating time was measured with a stopwatch. The differences between impressions made for maxillary and mandibular implants were also compared. The data were analyzed with paired and independent sample t tests, and effect sizes were calculated. Statistically significant differences were found in favor of the digital procedure regarding all subjective domains (P<.001), with medium to large effect sizes. Of all the participants, over 80% preferred the digital procedure to the analog procedure. The mean duration of digital impression making was 6 minutes and 39 seconds (SD=1:51) versus 12 minutes and 13 seconds (SD=1:24) for the analog impression (P<.001, effect size=2.7). Digital impression making for the restoration of a single implant crown takes less time than analog impression making. Furthermore, participants preferred the digital scan and reported less inconvenience, less shortness of breath, less fear of repeating the impression, and fewer feelings of helplessness during the procedure. Copyright © 2015 Editorial Council

Structure of ion-implanted ceramics

International Nuclear Information System (INIS)

Naramoto, Hiroshi

1983-01-01

The variation of structure of LiF, MgO, Al 2 O 3 and TiO 2 accompanying annealing after ion implantation is explained. The analysis of structure is usually made by the perturbed gamma ray angular correlation, the internal electron Moessbauer method, or the ion scattering method. The results of analyses are discussed for alkali ion implantation, Fe-ion implantation, In-ion implantation, Au-ion implantation, Pt-ion implantation, Pb-ion implantation and transition metal ion implantation. The coupling of the implanted elements with lattice defects and matrix elements, and the compatibility between deposited elements and matrix crystal lattice were studied. The variation of physical properties due to ion implantation such as phase transition, volume change, the control of single crystal region, and the variation of hardness near surface were investigated, and the examples are presented. (Kato, T.)

In Vivo Response of Laser Processed Porous Titanium Implants for Load-Bearing Implants.

Science.gov (United States)

Bandyopadhyay, Amit; Shivaram, Anish; Tarafder, Solaiman; Sahasrabudhe, Himanshu; Banerjee, Dishary; Bose, Susmita

2017-01-01

Applications of porous metallic implants to enhance osseointegration of load-bearing implants are increasing. In this work, porous titanium implants, with 25 vol.% porosity, were manufactured using Laser Engineered Net Shaping (LENS™) to measure the influence of porosity towards bone tissue integration in vivo. Surfaces of the LENS™ processed porous Ti implants were further modified with TiO 2 nanotubes to improve cytocompatibility of these implants. We hypothesized that interconnected porosity created via additive manufacturing will enhance bone tissue integration in vivo. To test our hypothesis, in vivo experiments using a distal femur model of male Sprague-Dawley rats were performed for a period of 4 and 10 weeks. In vivo samples were characterized via micro-computed tomography (CT), histological imaging, scanning electron microscopy, and mechanical push-out tests. Our results indicate that porosity played an important role to establish early stage osseointegration forming strong interfacial bonding between the porous implants and the surrounding tissue, with or without surface modification, compared to dense Ti implants used as a control.

In vivo response of laser processed porous titanium implants for load-bearing implants

Science.gov (United States)

Bandyopadhyay, Amit; Shivaram, Anish; Tarafder, Solaiman; Sahasrabudhe, Himanshu; Banerjee, Dishary; Bose, Susmita

2016-01-01

Applications of porous metallic implants to enhance osseointegration of load-bearing implants are increasing. In this work, porous titanium implants, with 25 volume% porosity, were manufactured using Laser Engineered Net Shaping (LENS™) to measure the influence of porosity towards bone tissue integration in vivo. Surfaces of the LENS™ processed porous Ti implants were further modified with TiO2 nanotubes to improve cytocompatibility of these implants. We hypothesized that interconnected porosity created via additive manufacturing will enhance bone tissue integration in vivo. To test our hypothesis, in vivo experiments using a distal femur model of male Sprague-Dawley rats were performed for a period of 4 and 10 weeks. In vivo samples were characterized via micro-computed tomography (CT), histological imaging, scanning electron microscopy, and mechanical push-out tests. Our results indicate that porosity played an important role to establish early stage osseointegration forming strong interfacial bonding between the porous implants and the surrounding tissue, with or without surface modification, compared to dense Ti implants used as a control. PMID:27307009

Optimizing anterior esthetics of a single-tooth implant through socket augmentation and immediate provisionalization: A case report with 7-year follow-up

Directory of Open Access Journals (Sweden)

Po-Sung Fu

2012-10-01

Full Text Available Tooth extraction inevitably accompanies alveolar ridge resorption with loss of pre-existing tissue morphology. Replacing missing teeth with dental implants has become popular, but restoring anterior teeth with implant-supported restorations is a technique-sensitive task and poses challenges for dentists. With the progress of implant dentistry, the demand for optimal esthetics has become linked with the desire for faster, easier techniques that shorten treatment time and also satisfy patients. Immediate provisionalization of a single-tooth implant provides significant benefits compared with traditional delayed protocols, such as aiding the contouring of peri-implant soft tissue and enhancing patient comfort and satisfaction. This article describes a meticulous approach to a hopeless maxillary central incisor with root fracture. The defect in the extraction socket was reconstructed using autogenous bone harvested from the chin. Four months later, an implant was installed and immediately restored. After another healing period of 6 months, the peri-implant soft tissue had been shaped and matured according to the contours of the provisional restoration. The emergence profile was used to duplicate the definitive restoration. Peri-implant esthetics was achieved through socket augmentation and immediate provisionalization of the implant. This treatment modality attained predictable and maintainable outcomes, both functionally and esthetically.

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.

Single-stage transforaminal decompression, debridement, interbody fusion, and posterior instrumentation for lumbosacral brucellosis.

Science.gov (United States)

Abulizi, Yakefu; Liang, Wei-Dong; Muheremu, Aikeremujiang; Maimaiti, Maierdan; Sheng, Wei-Bin

2017-07-14

Spinal brucellosis is a less commonly reported infectious spinal pathology. There are few reports regarding the surgical treatment of spinal brucellosis in existing literature. This retrospective study was conducted to determine the effectiveness of single-stage transforaminal decompression, debridement, interbody fusion, and posterior instrumentation for lumbosacral spinal brucellosis. From February 2012 to April 2015, 32 consecutive patients (19 males and 13 females, mean age 53.7 ± 8.7) with lumbosacral brucellosis treated by transforaminal decompression, debridement, interbody fusion, and posterior instrumentation were enrolled. Medical records, imaging studies, laboratory data were collected and summarized. Surgical outcomes were evaluated based on visual analogue scale (VAS), Oswestry Disability Index (ODI) and Japanese Orthopaedic Association (JOA) scale. The changes in C-reactive protein (CRP) levels, erythrocyte sedimentation rate (ESR), clinical symptoms and complications were investigated. Graft fusion was evaluated using Bridwell grading criteria. The mean follow-up period was 24.9 ± 8.2 months. Back pain and radiating leg pain was relieved significantly in all patients after operation. No implant failures were observed in any patients. Wound infection was observed in two patients and sinus formation was observed in one patient. Solid bony fusion was achieved in 30 patients and the fusion rate was 93.8%. The levels of ESR and CRP were returned to normal by the end of three months' follow-up. VAS and ODI scores were significantly improved (P brucellosis.

Current Concepts in Restorative Implant Dentistry

Institute of Scientific and Technical Information of China (English)

Prof.Marchack

2009-01-01

Patients today are incteasingly aware of dental implants.and their expectations are for esthetically and functionally pleasingimplant restorations that mimic natural teeth.This presentation will give both the experienced and novice practitioner a better understand-ing of how restorative implant dentistry has evolved.Treatment planning and restorative options for single implants.multiple implants andfully edentulons arches will be discussed,and the use of modern materials and CADCAM technology in fabricating the most contemporaryfixed implant supported prostheses will be demonstrated.

CLINICAL EVALUATION OF THE STABILITY OF IMPLANTS PLACED AT DIFFERENT SUPRACRESTAL LEVELS

Directory of Open Access Journals (Sweden)

B. Alper GÜLTEKIN

2016-10-01

Full Text Available Purpose: The aim of this study was to evaluate the stability during healing and before loading of implants placed at two different supracrestal levels according to their collar texture. Materials and Methods: This retrospective study included patients who received posterior implants with the same macro design. Implants with a machined collar were placed 0.3 mm above the crestal bone (M group, while those with a laser-microtextured collar were placed 1 mm above the crestal bone (L group. All implants healed in a single stage with healing abutments. Implant stability quotient (ISQ values were determined using resonance frequency analysis immediately after implant placement during surgery and after 1, 4, 8, and 12 weeks after surgery. Other evaluated factors for stability included the implant diameter and length and the site of placement (maxilla or mandible. Results: In total, 103 implants (47 L, 56 M were evaluated. The median ISQ values at baseline and 1 week after placement were significantly higher for the M group than for the L group (p=0.006 and p=0.031, respectively. There were no differences at the subsequent observation points. The ISQ value was higher for wide-diameter than regular diameter (p=0.001 and mandibular implants than maxillary implants (p=0.001 at 0-8. weeks; p=0.012 at 12 weeks at all observation points. When diameter data were neglected, the implant length did not influence the ISQ value at all observation points. Conclusion: Our results suggest that submerging implant more inside bone may only influence primary stability. Moreover, the implant diameter and site of placement influence primary and secondary stability before loading, whereas the implant length does not when its diameter is not accounted for.

Analysis of submerged implant towards mastication load using 3D finite element method (FEM)

OpenAIRE

Widia Hafsyah Sumarlina Ritonga; Janti Rusjanti; Nunung Rusminah; Aldilla Miranda; Tatacipta Dirgantara

2016-01-01

Introduction: The surgical procedure for implantation of a surgical implant comprising a stage for the implant design nonsubmerged and two stages for submerged. Submerged implant design often used in Faculty of Dentistry Universitas Padjadjaran because it is safer in achieving osseointegration. This study was conducted to evaluate the failure of dental implant based on location and the value of internal tensiones as well as supporting tissues when given mastication load by using the 3D Finite...

Recording single neurons' action potentials from freely moving pigeons across three stages of learning.

Science.gov (United States)

Starosta, Sarah; Stüttgen, Maik C; Güntürkün, Onur

2014-06-02

While the subject of learning has attracted immense interest from both behavioral and neural scientists, only relatively few investigators have observed single-neuron activity while animals are acquiring an operantly conditioned response, or when that response is extinguished. But even in these cases, observation periods usually encompass only a single stage of learning, i.e. acquisition or extinction, but not both (exceptions include protocols employing reversal learning; see Bingman et al.(1) for an example). However, acquisition and extinction entail different learning mechanisms and are therefore expected to be accompanied by different types and/or loci of neural plasticity. Accordingly, we developed a behavioral paradigm which institutes three stages of learning in a single behavioral session and which is well suited for the simultaneous recording of single neurons' action potentials. Animals are trained on a single-interval forced choice task which requires mapping each of two possible choice responses to the presentation of different novel visual stimuli (acquisition). After having reached a predefined performance criterion, one of the two choice responses is no longer reinforced (extinction). Following a certain decrement in performance level, correct responses are reinforced again (reacquisition). By using a new set of stimuli in every session, animals can undergo the acquisition-extinction-reacquisition process repeatedly. Because all three stages of learning occur in a single behavioral session, the paradigm is ideal for the simultaneous observation of the spiking output of multiple single neurons. We use pigeons as model systems, but the task can easily be adapted to any other species capable of conditioned discrimination learning.

Two-stage single-volume exchange transfusion in severe hemolytic disease of the newborn.

Science.gov (United States)

Abbas, Wael; Attia, Nayera I; Hassanein, Sahar M A

2012-07-01

Evaluation of two-stage single-volume exchange transfusion (TSSV-ET) in decreasing the post-exchange rebound increase in serum bilirubin level, with subsequent reduction of the need for repeated exchange transfusions. The study included 104 neonates with hyperbilirubinemia needing exchange transfusion. They were randomly enrolled into two equal groups, each group comprised 52 neonates. TSSV-ET was performed for the 52 neonates and the traditional single-stage double-volume exchange transfusion (SSDV-ET) was performed to 52 neonates. TSSV-ET significantly lowered rebound serum bilirubin level (12.7 ± 1.1 mg/dL), compared to SSDV-ET (17.3 ± 1.7 mg/dL), p < 0.001. Need for repeated exchange transfusions was significantly lower in TSSV-ET group (13.5%), compared to 32.7% in SSDV-ET group, p < 0.05. No significant difference was found between the two groups as regards the morbidity (11.5% and 9.6%, respectively) and the mortality (1.9% for both groups). Two-stage single-volume exchange transfusion proved to be more effective in reducing rebound serum bilirubin level post-exchange and in decreasing the need for repeated exchange transfusions.

Identifying cochlear implant channels with poor electrode-neuron interface: partial tripolar, single-channel thresholds and psychophysical tuning curves.

Science.gov (United States)

Bierer, Julie Arenberg; Faulkner, Kathleen F

2010-04-01

The goal of this study was to evaluate the ability of a threshold measure, made with a restricted electrode configuration, to identify channels exhibiting relatively poor spatial selectivity. With a restricted electrode configuration, channel-to-channel variability in threshold may reflect variations in the interface between the electrodes and auditory neurons (i.e., nerve survival, electrode placement, and tissue impedance). These variations in the electrode-neuron interface should also be reflected in psychophysical tuning curve (PTC) measurements. Specifically, it is hypothesized that high single-channel thresholds obtained with the spatially focused partial tripolar (pTP) electrode configuration are predictive of wide or tip-shifted PTCs. Data were collected from five cochlear implant listeners implanted with the HiRes90k cochlear implant (Advanced Bionics Corp., Sylmar, CA). Single-channel thresholds and most comfortable listening levels were obtained for stimuli that varied in presumed electrical field size by using the pTP configuration for which a fraction of current (sigma) from a center-active electrode returns through two neighboring electrodes and the remainder through a distant indifferent electrode. Forward-masked PTCs were obtained for channels with the highest, lowest, and median tripolar (sigma = 1 or 0.9) thresholds. The probe channel and level were fixed and presented with either the monopolar (sigma = 0) or a more focused pTP (sigma > or = 0.55) configuration. The masker channel and level were varied, whereas the configuration was fixed to sigma = 0.5. A standard, three-interval, two-alternative forced choice procedure was used for thresholds and masked levels. Single-channel threshold and variability in threshold across channels systematically increased as the compensating current, sigma, increased and the presumed electrical field became more focused. Across subjects, channels with the highest single-channel thresholds, when measured with a

Patients' perceptions of implant placement surgery, the post-surgical healing and the transitional implant prostheses: a qualitative study.

Science.gov (United States)

Kashbour, Wafa A; Rousseau, Nikki; Thomason, J Mark; Ellis, Janice S

2017-07-01

This study aimed to explore patients' thoughts, feelings about, and experiences of, implant placement surgery (IPS), the post-surgical healing stage and the immediate post-surgical transitional implant prosthesis (TIP) (fixed and removable). A qualitative study design was chosen and 38 semi-structured telephone and face-to-face interviews were conducted with 34 patients at different stages of implant treatment. The interviews were transcribed verbatim; the data collection and coding process followed the principles of thematic analysis, which was facilitated through the use of NVivo10. Patients anticipated that surgery would be painful and unpleasant but were prepared to accept this temporary discomfort for the expected benefits of implant treatment. However, a key finding was that patients felt they had overestimated the trauma of surgery but underestimated the discomfort and difficulties of the healing phase. A number of difficulties were also identified with the TIP phase following implant surgery. Existing research has tended to focus on the longer term benefits of dental implant treatment. This qualitative study has investigated in-depth patients' perceptions of dental implant surgery, including their experiences related to sedation, and of transitional implant restoration. While patients felt their concerns were overestimated in relation to the implant surgery, they experienced greater morbidity than they expected in the healing phase. Recommendations are made for relatively small changes in care provision which might improve the overall patient experience. Partial dentate patients treated with a fixed transitional prosthesis experienced advantages more quickly than patients with an overdenture. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Multimodality Imaging-based Evaluation of Single-Lumen Silicone Breast Implants for Rupture.

Science.gov (United States)

Seiler, Stephen J; Sharma, Pooja B; Hayes, Jody C; Ganti, Ramapriya; Mootz, Ann R; Eads, Emily D; Teotia, Sumeet S; Evans, W Phil

2017-01-01

Breast implants are frequently encountered on breast imaging studies, and it is essential for any radiologist interpreting these studies to be able to correctly assess implant integrity. Ruptures of silicone gel-filled implants often occur without becoming clinically obvious and are incidentally detected at imaging. Early diagnosis of implant rupture is important because surgical removal of extracapsular silicone in the breast parenchyma and lymphatics is difficult. Conversely, misdiagnosis of rupture may prompt a patient to undergo unnecessary additional surgery to remove the implant. Mammography is the most common breast imaging examination performed and can readily depict extracapsular free silicone, although it is insensitive for detection of intracapsular implant rupture. Ultrasonography (US) can be used to assess the internal structure of the implant and may provide an economical method for initial implant assessment. Common US signs of intracapsular rupture include the "keyhole" or "noose" sign, subcapsular line sign, and "stepladder" sign; extracapsular silicone has a distinctive "snowstorm" or echogenic noise appearance. Magnetic resonance (MR) imaging is the most accurate and reliable means for assessment of implant rupture and is highly sensitive for detection of both intracapsular and extracapsular rupture. MR imaging findings of intracapsular rupture include the keyhole or noose sign, subcapsular line sign, and "linguine" sign, and silicone-selective MR imaging sequences are highly sensitive to small amounts of extracapsular silicone. © RSNA, 2017.

Single-stage micro-scale solvent extraction in parallel microbore tubes using MDIMJ

International Nuclear Information System (INIS)

Darekar, Mayur; Singh, K.K.; Joshi, J.M.; Mukhopadhyay, S.; Shenoy, K.T.

2016-01-01

Single-stage micro-scale solvent extraction of U(VI) from simulated lean streams is explored using micro-scale contactor comprising of a MDIMJ (Monoblock Distributor with Integrated Microfluidic Junction) and PTFE microbore tubes. 30% (v/v) TBP in dodecane has been used as the extracting phase. The objective of the study is to demonstrate numbering up approach for scale-up of micro-scale extraction using indigenously conceptualized and fabricated MDIMJ. First the performance of MIDIMJ for equal flow distribution is tested. Then the effects of inlet flow rate and O/A ratio on stage efficiency and percentage extraction are studied. The experiments show that it is easy to scale-up single-stage micro-scale solvent extraction by using MDIMJ for numbering up approach. Maximum capacity tested is 4.8 LPH. With O/A = 2/1, more than 90% extraction is achieved in a very short contact time of less than 3s. The study thus demonstrates possibility of process intensification and easy scale-up of micro-scale solvent extraction

Fracture Strength and Failure Mode of Maxillary Implant-Supported Provisional Single Crowns : A Comparison of Composite Resin Crowns Fabricated Directly Over PEEK Abutments and Solid Titanium Abutments

NARCIS (Netherlands)

Santing, H.J.; Meijer, Henny J.A.; Raghoebar, G.M.; Ozcan, M.

2012-01-01

Background: Polyetheretherketone (PEEK) temporary abutments have been recently introduced for making implant-supported provisional single crowns. Little information is available in the dental literature on the durability of provisional implant-supported restorations. Purpose: The objectives of this

Tapered, Double-Lead Threads Single Implants Placed in Fresh Extraction Sockets and Healed Sites of the Posterior Jaws: A Multicenter Randomized Controlled Trial with 1 to 3 Years of Follow-Up.

Science.gov (United States)

Cucchi, Alessandro; Vignudelli, Elisabetta; Franco, Simonetta; Levrini, Luca; Castellani, Dario; Pagliani, Luca; Rea, Massimiliano; Modena, Claudio; Sandri, Giulio; Longhi, Carlo

2017-01-01

To evaluate the survival, success, and complication rates of tapered double-lead threads single implants, placed in fresh extraction sockets and healed sites of the posterior jaws. The enrolled patients were randomly divided into 2 groups: in the test group (TG), all implants were inserted at the time of tooth extraction; in the control group (CG), all implants were placed 3 months after extraction. The implants were followed for a period of 1 to 3 years after loading. The main outcomes were implant survival, complications, and implant-crown success. Ninety-two patients had 97 installed implants (49 in the TG, 48 in the CG). Only two implants failed, in the TG; the survival rates were therefore 95.9% (47/49) and 100% (48/48) for TG and CG, respectively. In the surviving implants, no complications were reported, for an implant-crown success of 100%. Although a significant difference was found in the levels of primary stability between TG and CG, single implants placed in fresh extraction sockets and healed sites of the posterior jaws had similar survival and complication rates. Crestal bone levels and peri-implant bone resorption showed similar values. A longer follow-up period is however required, to confirm these positive outcomes.

Novel Techniques with the Aid of a Staged CBCT Guided Surgical Protocol

Directory of Open Access Journals (Sweden)

Evdokia Chasioti

2015-01-01

Full Text Available The case report will present some novel techniques for using a “staged” protocol utilizing strategic periodontally involved teeth as transitional abutments in combination with CBCT guided implant surgery. Staging the case prevented premature loading of the grafted sites during the healing phase. A CBCT following a tenting screw guided bone regeneration procedure ensured adequate bone to place an implant fixture. Proper assessment of the CBCT allowed the surgeon to do an osteotome internal sinus lift in an optimum location. The depth of the bone needed for the osteotome sinus floor elevation was planned. The staged appliance allowed these sinus-augmented sites to heal for an extended period of time compared to implants, which were uncovered and loaded at an earlier time frame. The staged protocol and CBCT analysis enabled the immediate implants to be placed in proper alignment to the adjacent fixture. After teeth were extracted, the osseointegrated implants were converted to abutments for the transitional appliance. Finally, the staged protocol allowed for soft tissue enhancement in the implant and pontic areas prior to final insertion of the prosthesis.

Impact of cone-beam computed tomography on implant planning and on prediction of implant size

Energy Technology Data Exchange (ETDEWEB)

Pedroso, Ludmila Assuncao de Mello; Silva, Maria Alves Garcia Santos, E-mail: ludmilapedroso@hotmail.com [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia; Garcia, Robson Rodrigues [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Medicina Oral; Leles, Jose Luiz Rodrigues [Universidade Paulista (UNIP), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Cirurgia; Leles, Claudio Rodrigues [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Prevencao e Reabilitacao Oral

2013-11-15

The aim was to investigate the impact of cone-beam computed tomography (CBCT) on implant planning and on prediction of final implant size. Consecutive patients referred for implant treatment were submitted to clinical examination, panoramic (PAN) radiography and a CBCT exam. Initial planning of implant length and width was assessed based on clinical and PAN exams, and final planning, on CBCT exam to complement diagnosis. The actual dimensions of the implants placed during surgery were compared with those obtained during initial and final planning, using the McNemmar test (p < 0.05). The final sample comprised 95 implants in 27 patients, distributed over the maxilla and mandible. Agreement in implant length was 50.5% between initial and final planning, and correct prediction of the actual implant length was 40.0% and 69.5%, using PAN and CBCT exams, respectively. Agreement in implant width assessment ranged from 69.5% to 73.7%. A paired comparison of the frequency of changes between initial or final planning and implant placement (McNemmar test) showed greater frequency of changes in initial planning for implant length (p < 0.001), but not for implant width (p = 0.850). The frequency of changes was not influenced by implant location at any stage of implant planning (chi-square test, p > 0.05). It was concluded that CBCT improves the ability of predicting the actual implant length and reduces inaccuracy in surgical dental implant planning. (author)

Monte Carlo simulation of boron-ion implantation into single-crystal silicon

International Nuclear Information System (INIS)

Klein, K.M.

1991-01-01

A physically based Monte Carlo boron implantation model developed comprehends previously neglected but important implant parameters such as native oxide layers, wafer temperature, beam divergence, tilt angle, rotation (twist) angle, and dose, in addition to energy. This model uses as its foundation the MARLOWE Monte Carlo simulation code developed at Oak Ridge National Laboratory for the analysis of radiation effects in materials. This code was carefully adapted for the simulation of ion implantation, and a number of significant improvements have been made, including the addition of atomic pair specific interatomic potentials, the implementation of a newly developed local electron concentration dependent electronic stopping model, and the implementation of a newly developed cumulative damage model. This improved version of the code, known as UT-MARLOWE, allows boron implantation profiles to be accurately predicted as a function of energy, tilt angle, rotation angle, and dose. This code has also been used in the development and implementation of an accurate and efficient two-dimensional boron implantation model

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.

Single ion impact detection and scanning probe aligned ion implantation for quantum bit formation

International Nuclear Information System (INIS)

Weis, Christoph D.

2011-01-01

Quantum computing and quantum information processing is a promising path to replace classical information processing via conventional computers which are approaching fundamental physical limits. Instead of classical bits, quantum bits (qubits) are utilized for computing operations. Due to quantum mechanical phenomena such as superposition and entanglement, a completely different way of information processing is achieved, enabling enhanced performance for certain problem sets. Various proposals exist on how to realize a quantum bit. Among them are electron or nuclear spins of defect centers in solid state systems. Two such candidates with spin degree of freedom are single donor atoms in silicon and nitrogen vacancy (NV) defect centers in diamond. Both qubit candidates possess extraordinary qualities which makes them promising building blocks. Besides certain advantages, the qubits share the necessity to be placed precisely in their host materials and device structures. A commonly used method is to introduce the donor atoms into the substrate materials via ion implantation. For this, focused ion beam systems can be used, or collimation techniques as in this work. A broad ion beam hits the back of a scanning probe microscope (SPM) cantilever with incorporated apertures. The high resolution imaging capabilities of the SPM allows the non destructive location of device areas and the alignment of the cantilever and thus collimated ion beam spot to the desired implant locations. In this work, this technique is explored, applied and pushed forward to meet necessary precision requirements. The alignment of the ion beam to surface features, which are sensitive to ion impacts and thus act as detectors, is demonstrated. The technique is also used to create NV center arrays in diamond substrates. Further, single ion impacts into silicon device structures are detected which enables deliberate single ion doping.

Single ion impact detection and scanning probe aligned ion implantation for quantum bit formation

Energy Technology Data Exchange (ETDEWEB)

Weis, Christoph D.

2011-10-04

Quantum computing and quantum information processing is a promising path to replace classical information processing via conventional computers which are approaching fundamental physical limits. Instead of classical bits, quantum bits (qubits) are utilized for computing operations. Due to quantum mechanical phenomena such as superposition and entanglement, a completely different way of information processing is achieved, enabling enhanced performance for certain problem sets. Various proposals exist on how to realize a quantum bit. Among them are electron or nuclear spins of defect centers in solid state systems. Two such candidates with spin degree of freedom are single donor atoms in silicon and nitrogen vacancy (NV) defect centers in diamond. Both qubit candidates possess extraordinary qualities which makes them promising building blocks. Besides certain advantages, the qubits share the necessity to be placed precisely in their host materials and device structures. A commonly used method is to introduce the donor atoms into the substrate materials via ion implantation. For this, focused ion beam systems can be used, or collimation techniques as in this work. A broad ion beam hits the back of a scanning probe microscope (SPM) cantilever with incorporated apertures. The high resolution imaging capabilities of the SPM allows the non destructive location of device areas and the alignment of the cantilever and thus collimated ion beam spot to the desired implant locations. In this work, this technique is explored, applied and pushed forward to meet necessary precision requirements. The alignment of the ion beam to surface features, which are sensitive to ion impacts and thus act as detectors, is demonstrated. The technique is also used to create NV center arrays in diamond substrates. Further, single ion impacts into silicon device structures are detected which enables deliberate single ion doping.

Ion implantation - an introduction

International Nuclear Information System (INIS)

Townsend, P.D.

1986-01-01

Ion implantation is a widely used technique with a literature that covers semiconductor production, surface treatments of steels, corrosion resistance, catalysis and integrated optics. This brief introduction outlines advantages of the technique, some aspects of the underlying physics and examples of current applications. Ion implantation is already an essential part of semiconductor technology while in many other areas it is still in an early stage of development. The future scope of the subject is discussed. (author)

PINCH1 regulates cell-matrix and cell-cell adhesions, cell polarity and cell survival during the peri-implantation stage

DEFF Research Database (Denmark)

Li, Shaohua; Bordoy, Randi; Stanchi, Fabio

2005-01-01

PINCH1 is composed of 5 LIM domains, binds integrin-linked kinase (ILK) and locates to integrin-mediated adhesion sites. In order to investigate PINCH1 function we generated mice and embryonic stem (ES) cell-derived embryoid bodies (EBs) lacking the PINCH1 gene. Similar to mice lacking beta1...... integrin or Ilk, loss of PINCH1 arrested development at the peri-implantation stage. In contrast to beta1 integrin or Ilk mutants, however, disruption of the PINCH1 gene produced implantation chambers with visible cell clumps even at embryonic day 9.5. In order to define the phenotype leading to the peri...... not observed in beta1 integrin- or ILK-deficient mice or EBs, included abnormal cell-cell adhesion of endoderm and epiblast as well as the presence of apoptotic cells in the endodermal cell layer. Although ILK and PINCH1 were shown to be involved in the phosphorylation of serine-473 of PKB/Akt, immunostaining...

One-stage revision of infected hip arthroplasty: outcome of 39 consecutive hips.

Science.gov (United States)

Ilchmann, Thomas; Zimmerli, Werner; Ochsner, Peter Emil; Kessler, Bernhard; Zwicky, Lukas; Graber, Peter; Clauss, Martin

2016-05-01

There are various options for treating periprosthetic joint infection (PJI). Two-stage exchange has traditionally been the gold standard. However, if the appropriate surgical intervention is chosen according to a rational algorithm, the outcome is similar when using all types of interventions. In an observational cohort study, the outcome of patients with PJI after hip replacement treated with one-stage revision was analysed. All patients fulfilling all criteria for one-stage exchange according to the Infectious Diseases Society of America (IDSA) guidelines and six without preoperative identification of a microorganism were included. Implant removal, debridement and cemented or uncemented reimplantations were performed in a single intervention. If a cemented device was implanted, commercially available gentamicin cement was used in all cases. Antibiotic treatment was administered intravenously for at least 2 weeks, followed by oral therapy for a total duration of 3 months. Patients had standardised clinical and radiological follow-up visits. Between 1996 and 2011, 38 patients (39 hips) were treated with a one-stage procedure and followed for at least 2 years. Coagulase-negative staphylococci were the most frequent pathogens, and polymicrobial infection was observed in five cases. In 25 hips, an uncemented revision stem was implanted, and 37 hips received an acetabular reinforcement ring. The mean follow-up was 6.6 (2.0-15.1) years. No patient had persistent, recurrent or new infection. There were four stem revisions for aseptic loosening. The mean Harris Hip Score was 81 points (26-99) at the final follow-up. Excellent cure rate and function seen in our study suggest that one-stage exchange is a safe procedure, even without local antibiotic treatment, provided that the patient has no sinus tract or severe soft tissue damage, no major bone grafting is required and the microorganism is susceptible to orally administered agents with high bioavailability.

Efficacy of single-stage breast-conserving treatment using multicatheter partial breast brachytherapy evaluated by GEC-ESTRO phase 3 trial.

Science.gov (United States)

Sato, Kazuhiko; Fuchikami, Hiromi; Kato, Masahiro; Shimo, Takahiro; Kubota, Jun; Takeda, Naoko; Inoue, Yuko; Seto, Hiroshi; Okawa, Tomohiko

2017-10-01

The GEC-ESTRO has reported the equivalent outcomes of partial breast irradiation (PBI) using multicatheter interstitial brachytherapy (MCB) to whole breast irradiation (WBI) in breast-conserving therapy (BCT). We performed single-stage BCT with partial breast brachytherapy by intraoperative catheter placement. After the categorization of patients into inclusion and exclusion criteria on this trial, our databases were evaluated in order to translate it to Japanese patients. Patients undergoing BCT were retrospectively examined between November 2007 and December 2015. The technique is an open-cavity implant with a dose of 32 Gy in 8 fractions. The 4-year clinical outcomes of MCB-PBI were evaluated in the 2 distinct categories, and the comparison of the outcomes of MCB-PBI with WBI was performed in patients with unfavorable features. Of a total of 501 lesions undergoing BCT, 301 lesions were treated with MCB-PBI and 200 lesions with WBI. At the median follow-up time of 52 months, the 4-year rate of ipsilateral breast tumor recurrence (IBTR)-free, disease-free (DFS), and overall survival (OS) in patients with MCB-PBI and WBI were 98.9% vs. 98.0% ( p = 0.56), 97.0% vs. 95.3% ( p = 0.78), and 99.6% vs. 98.2% ( p = 0.38), respectively. Although in exclusion cohort treated with MCB-PBI, IBTR-free, and disease-free survival were significantly worse than in inclusion cohort, non-significantly worse outcomes was demonstrated than in exclusion cohort with WBI; IBTR-free survival (95.0% vs. 97.2%, p = 0.24), and disease-free survival (95.0% vs. 95.8%, p = 0.31). Single-stage BCT using MCB-PBI offered similar tumor control rates compering to WBI. However, further research is needed to define the benefit for patients with an exclusion criteria.

Attitudes of general dental practitioners towards implant dentistry in an environment with widespread provision of implant therapy.

Science.gov (United States)

Lang-Hua, Bich Hue; Lang, Niklaus P; Lo, Edward C M; McGrath, Colman P J

2013-03-01

To determine attitudes of general dental practitioners in a community where provision dental implants is a well-known treatment modality; and to identify variations in the attitudes with respect to dentists' factors, training factors and implant provision factors. A questionnaire survey to a random sample of registered dentists In Hong Kong was performed. Attitudes towards implant dentistry with respect to (i) perceived superiority of implant therapy, (ii) perceived outcomes of dental implant therapy, (iii) perceived complications & maintenance issues and (iv) placement issues were ascertained. In addition, information was collected on dentists' factors, training factors and implant provision factors. Variations in attitudes towards implant dentistry were explored in bivariate and regression analyses. Among eligible practitioners (n = 246), the response rate was 46.3%. Dentists perceived implants to be superior to conventional prostheses for the replacement of a single missing posterior tooth (80%, 67) and likewise, for the replacement of a single missing anterior tooth (67%, 67), P attitudes with respect to attitudes exists with respect to dentists' factors (years in practice [P attitudes are not wholly in line with evidence-based knowledge. Variations in their attitudes existed with respect to dentist factors, training and experience issues. © 2012 John Wiley & Sons A/S.

Amorphous clusters in Co implanted ZnO induced by boron pre-implantation

Energy Technology Data Exchange (ETDEWEB)

Potzger, K.; Shalimov, A.; Zhou, S.; Schmidt, H.; Mucklich, A.; Helm, M.; Fassbender, J.; Liberati, M.; Arenholz, E.

2009-02-09

We demonstrate the formation of superparamagnetic/ferromagnetic regions within ZnO(0001) single crystals sequently implanted with B and Co. While the pre-implantation with B plays a minor role for the electrical transport properties, its presence leads to the formation of amorphous phases. Moreover, B acts strongly reducing on the implanted Co. Thus, the origin of the ferromagnetic ordering in local clusters with large Co concentration is itinerant d-electrons as in the case of metallic Co. The metallic amorphous phases are non-detectable by common X-ray diffraction.

Improving osseointegration of dental implants.

Science.gov (United States)

Elias, Carlos Nelson; Meirelles, Luiz

2010-03-01

In the beginning of implantology, the procedures adopted for treating patients were performed in two surgical phases with an interval of 3-6 months. Nowadays, it is possible to insert and load a dental implant in the same surgical procedure. This change is due to several factors, such as improvement of surgical technique, modifications of the implant design, increased quality of implant manufacturing, development of the surgical instruments' quality, careful patient screening and adequate treatment of the implant surface. The clinical results show that adequate treatment of surfaces is crucial for reducing healing time and treating at-risk patients. The surface properties of dental implants can be significantly improved at the manufacturing stage, affecting cells' activity during the healing phase that will ultimately determine the host tissue response, a fundamental requirement for clinical success. This review focuses on different types of dental implant surfaces and the influence of surface characteristics on osseointegration.

Evaluation of aesthetics of implant-supported single-tooth replacements using different bone augmentation procedures : A prospective randomized clinical study

NARCIS (Netherlands)

Meijndert, Leo; Meijer, Henny J. A.; Stellingsma, Kees; Stegenga, Boudewijn; Raghoebar, Gerry M.

2007-01-01

Objectives: The aim of this study was to evaluate the aesthetics of implant-supported single-tooth replacements using different augmentation procedures in a prospective study with the use of an objective rating index and with a subjective patient questionnaire, and to compare the results with each

Cochlear implant effectiveness in postlingual single-sided deaf individuals: what's the point?

Science.gov (United States)

Finke, Mareike; Bönitz, Hanna; Lyxell, Björn; Illg, Angelika

2017-06-01

By extending the indication criteria for cochlear implants (CI), the population of CI candidates increased in age, as well as range and type of hearing loss. This qualitative study identified factors that contributed to seek CI treatment in single-sided deaf individuals and gained insights how single-sided deafness (SSD) and hearing with a CI affect their lives. An open-ended questionnaire and a standardised inventory (IOI-HA) were used. Qualitative data reflecting the reasons to seek CI treatment and the individual experiences after CI switch-on were collected. A total of 19 postlingually deafened single-sided deaf CI users. Participants use their CI daily and stated that their life satisfaction increased since CI activation. The analysis of the qualitative data revealed four core categories: sound localisation, tinnitus and noise sensitivity, fear to lose the second ear and quality of life. Our results show how strongly and diversely quality of hearing and quality of life is affected by acquired SSD and improved after CI activation. Our data suggest that the fear of hearing loss (HL) on the normal hearing (NH) ear is an important but so far neglected reason to seek treatment with a CI in individuals with postlingual SSD.

Callus Distraction Versus Single-Stage Lengthening With Bone Graft for Treatment of Brachymetatarsia: A Systematic Review.

Science.gov (United States)

Jones, Marc D; Pinegar, David M; Rincker, Sarah A

2015-01-01

Brachymetatarsia deformity is a cosmetically displeasing anomaly that can become physically symptomatic. The surgical techniques most commonly used to repair the anomaly include single-stage lengthening with a bone graft, callus distraction, or a combination of bone grafting and callus distraction. A systematic review of the published data was performed to compare the outcomes of these 3 surgical procedures. A total of 61 studies reporting the use of callus distraction or single-stage lengthening, or both, for the treatment of brachymetatarsia were included in the present review. The incidence of major postoperative complications after callus distraction, single-stage lengthening, and the combination procedure was 49 (12.62%), 13 (3.72%), and 3 (33.33%), respectively. The number of minor complications with callus distraction, single-stage lengthening, and the combination procedure was 152 (39.18%), 55 (15.76%), and 1 (11.11%); the mean percentage of the original length achieved was 37.36%, 25.98% and 36.00%; and the mean length achieved was 17.5, 13.2, and 14.0 mm, respectively. The healing index (mo/cm) and healing time was 2.31 and 16.04 weeks, 1.90 and 9.35 weeks, and 3.93 and 14.62 weeks for callus distraction, single-stage lengthening, and the combination procedure, respectively. Our findings indicate that the callus distraction technique is associated with greater length gained but results in greater complication rates and requires almost twice the time to heal. Single-stage lengthening with a bone graft was associated with fewer complications and faster healing times than callus distraction but with lesser gains in length. From the information reported in the studies we reviewed, the prevalence of bilateral brachymetatarsia was 44.52%, and the female/male ratio was 13.7:1. Both of these findings seem to contradict the usual data given (72% for bilateral brachymetatarsia and a female/male ratio of 25:1). Copyright © 2015 American College of Foot and

Oral health related quality-of-life outcomes of partially edentulous patients treated with implant-supported single crowns or fixed partial dentures.

Science.gov (United States)

AlZarea, Bader K

2017-05-01

Oral health-related quality of life (OHRQoL) is afflicted by different variables. Limited information is available regarding the impact of different phases of implant therapy on OHRQoL of edentulous patients. This study was carried out to assess the OHRQoL of patients treated with implant-supported single crowns or fixed partial dentures. A total of 79 healthy partially edentulous subjects needing implant therapy were incorporated in this study. Before placement of the implants, the subjects were instructed to fill the original version of OHIP questionnaire. Subsequently patients received titanium oral implants of the ITI® Dental Implant System. After 1st, 2nd and 3rd year of implant placement, patients filled the same OHIP-49 questionnaire. In this manner the impact of implant therapy on OHRQoL by putting in comparison pre- and post-treatment OHIP-49 scores was assessed. Statistical analyses were performed using Statistical Package for the Social Science software (SPSS, version 22, Chicago, IL, USA). Paired t test and Unpaired t test were performed and a statistical significance was set at 5% level of significance ( p disability, psychological disability, social disability were significantly decreased from baseline to 1st year ( p 0.05). All variables were also significantly decreased from baseline to 2nd year and 3rd year ( p 0.05). Patients aged less than 60 years and more than 60 years of age groups differed significantly with respect to OHIP scores measured at 1st year, 2nd year and at 3rd year of implant placement ( p Oral health-related quality-of-life.

Ion implantation in semiconductor bodies

International Nuclear Information System (INIS)

Badawi, M.H.

1984-01-01

Ions are selectively implanted into layers of a semiconductor substrate of, for example, semi-insulating gallium arsenide via a photoresist implantation mask and a metallic layer of, for example, titanium disposed between the substrate surface and the photoresist mask. After implantation the mask and metallic layer are removed and the substrate heat treated for annealing purposes. The metallic layer acts as a buffer layer and prevents possible contamination of the substrate surface, by photoresist residues, at the annealing stage. Such contamination would adversely affect the electrical properties of the substrate surface, particularly gallium arsenide substrates. (author)

Fill Rates of Single-Stage and Multistage Supply Systems

OpenAIRE

Matthew J. Sobel

2004-01-01

A supply system's fill rate is the fraction of demand that is met from on-hand inventory. This paper presents formulas for the fill rate of periodic review supply systems that use base-stock-level policies. The first part of the paper contains fill-rate formulas for a single-stage system and general distributions of demand. When demand is normally distributed, an exact expression uses only the standard normal distribution and density functions, and a good approximation uses only the standard ...

Use of the frontal process of the maxillary bone for implant placement to retain a nasal prosthesis: a clinical report.

Science.gov (United States)

Proussaefs, Periklis

2004-01-01

Implant placement to provide support and retention for nasal prostheses has been described in the literature. The anatomic sites that have been utilized for implant placement are the nasal bones, the premaxillary area through the nasal fossae, and the anterior wall of the frontal sinus. In the patient described, after a presurgical computerized tomography scan to determine adequacy of bone volume, 1 conventional threaded hydroxyapatite-coated root-form implant, created for intraoral use, was placed in the frontal process of the maxillary bone and 2 additional conventional implants were placed in the premaxillary area through the nasal fossa. Six months after implant placement, second-stage surgery was completed. A single bar connecting the 3 implants was fabricated. The removable nasal prosthesis was retained on the bar with 2 clips. An examination 1 year postsurgery revealed no clinical signs of pathosis. Long-term clinical follow-up of this case should continue and a sufficient number of additional cases should be investigated before use of the frontal process of the maxillary bone for implant retention can be recommended on a routine basis.

One-Stage Immediate Breast Reconstruction: A Concise Review

Directory of Open Access Journals (Sweden)

Nicolò Bertozzi

2017-01-01

Full Text Available Background. One-stage direct-to-implant immediate breast reconstruction (IBR is performed simultaneously with breast cancer resection. We explored indications, techniques, and outcomes of IBR to determine its feasibility, safety, and effectiveness. Material and Methods. We reviewed the available literature on one-stage direct-to-implant IBR, with or without acellular dermal matrix (ADM, synthetic mesh, or autologous fat grafting. We analyzed the indications, preoperative work-up, surgical technique, postoperative care, outcomes, and complications. Results. IBR is indicated for small-to-medium nonptotic breasts and contraindicated in patients who require or have undergone radiotherapy, due to unacceptably high complications rates. Only patients with thick, well-vascularized mastectomy flaps are IBR candidates. Expandable implants should be used for ptotic breasts, while anatomical shaped implants should be used to reconstruct small-to-medium nonptotic breasts. ADMs can be used to cover the implant during IBR and avoid muscle elevation, thereby minimizing postoperative pain. Flap necrosis, reoperation, and implant loss are more common with IBR than conventional two-staged reconstruction, but IBR has advantages such as lack of secondary surgery, faster recovery, and better quality of life. Conclusions. IBR has good outcomes and patient-satisfaction rates. With ADM use, a shift from conventional reconstruction to IBR has occurred. Drawbacks of IBR can be overcome by careful patient selection.

Development of Implantable Medical Devices: From an Engineering Perspective

Directory of Open Access Journals (Sweden)

Yeun-Ho Joung

2013-09-01

Full Text Available From the first pacemaker implant in 1958, numerous engineering and medical activities for implantable medical device development have faced challenges in materials, battery power, functionality, electrical power consumption, size shrinkage, system delivery, and wireless communication. With explosive advances in scientific and engineering technology, many implantable medical devices such as the pacemaker, cochlear implant, and real-time blood pressure sensors have been developed and improved. This trend of progress in medical devices will continue because of the coming super-aged society, which will result in more consumers for the devices. The inner body is a special space filled with electrical, chemical, mechanical, and marine-salted reactions. Therefore, electrical connectivity and communication, corrosion, robustness, and hermeticity are key factors to be considered during the development stage. The main participants in the development stage are the user, the medical staff, and the engineer or technician. Thus, there are three different viewpoints in the development of implantable devices. In this review paper, considerations in the development of implantable medical devices will be presented from the viewpoint of an engineering mind.

A radiographic evaluation of progressive loading on crestal and bone density changes around single osseointegrated implants in the posterior maxilla

Directory of Open Access Journals (Sweden)

Ommati Shabestari Gh.

2009-11-01

Full Text Available "nBackground and Aim: The aim of this clinical study was to determine the effectiveness of progressive loading procedures on preserving crestal bone height and improving peri-implant bone density around maxillary implants restored with single crowns by an accurate longitudinal radiographic assessment technique. "n "n "nMaterials and Methods: Eleven Micro-Thread Osseo Speed dental implants were placed in 11 subjects and permitted to heal for 6 weeks before surgical uncovering. Following an 8-week healing period, implants underwent a progressive loading protocol by increasing the height of the occlusal table in increments from adding acrylic resin to an acrylic crown. The progressively loaded crowns were placed in 2 mm infraocclusion for the first 2 months, light occlusion for the second 2 months, and full occlusion for the third 2 months. At forth 2 months, a metal ceramic crown replaced the acrylic crown. Digital radiographs of each implant were made at the time of restoration, then after 2, 4, 6, 8, and 12 months of function. Digital image analysis was done to measure changes in crestal bone height and peri-implant bone density. "n "n "nResults: The mean values of crestal bone loss at 12 months were 0.11 ± 0.19 mm, and when tested with Friedman across the time periods, the differences were not statistically significant (p> 0.05. The mean values of bone density in the crestal, middle, and apical area were tested with Repeated Measure ANOVA across the time periods, the differences were statistically significant (p<0.05. "n "n "nConclusion: Progressive loading doesn’t cause crestal bone loss. The peri-implant density measurements of the progressively loaded implants show continuous increase in crestal, middle and apical peri-implant bone density by time. "n 

Unplanned Start on Peritoneal Dialysis Right after PD Catheter Implantation for Older People with End-Stage Renal Disease.

Science.gov (United States)

Povlsen, Johan V; Sørensen, Anette Bagger; Ivarsen, Per

2015-11-01

Unplanned start on dialysis remains a major problem for the dialysis community worldwide. Late-referred patients with end-stage renal disease (ESRD) and urgent need for dialysis are overrepresented among older people. These patients are particularly likely to be started on in-center hemodialysis (HD), with a temporary vascular access known to be associated with excess mortality and increased risks of potentially lethal complications such as bacteremia and central venous thrombosis or stenosis.The present paper describes in detail our program for unplanned start on automated peritoneal dialysis (APD) right after PD catheter implantation and summarizes our experiences with the program so far. Compared with planned start on PD after at least 2 weeks of break-in between PD catheter implantation and initiation of dialysis, unplanned start may be associated with a slight increased risk of mechanical complications but apparently no detrimental effect on mortality, peritonitis-free survival, or PD technique survival.In our opinion and experience, the risk of serious complications associated with the implantation and immediate use of a PD catheter is less than the risk of complications associated with unplanned start on HD with a temporary central venous catheter (CVC). Unplanned start on APD is a gentle, safe, and feasible alternative to unplanned start on HD with a temporary CVC that is also valid for the late-referred older patient with ESRD and urgent need for dialysis. Copyright © 2015 International Society for Peritoneal Dialysis.

Experimental study on bone tissue reaction around HA implants radiated after implantation

International Nuclear Information System (INIS)

Kudo, Masato; Matsui, Yoshiro; Tamura, Sayaka; Chen, Xuan; Uchida, Haruo; Mori, Kimie; Ohno, Kohsuke; Michi, Ken-ichi

1998-01-01

This study was conducted to investigate histologically and histomorphometrically the tissue reaction around hydroxylapatite (HA) implants that underwent irradiation in 3 different periods in the course of bone healing after implantation. The cylindrical high-density HA implants were implanted in 48 Japanese white rabbit mandibles. A single 15 Gy dose was applied to the mandible 5, 14, or 28 days after implantation. The rabbits were sacrificed 7, 14, 28, and 90 days after irradiation. Nonirradiated rabbits were used as controls. CMR, labeling with tetracycline and calcein, and non-decalcified specimens stained with toluidine blue were used for histological analyses and histomorphometric measurements. The results were as follows: In the rabbits irradiated 5 days after implantation, the HA-bone contact was observed later than that in the controls and the bone-implant contact surface ratio was lower than that in the controls at examination because necrosis of the newly-formed bone occurred just after irradiation. HA-bone contact of the rabbits irradiated 14 and 28 days after implantation was similar to that of the controls. And, bone remodeling was suppressed in rabbits of each group sacrificed at 90 days after irradiation. The results suggested that a short interval between implantation and irradiation causes direct contact between HA implant and bone and a long lapse of time before irradiation hardly affects the bone-implant contact, but delays bone remodeling. Therefore, it is necessary to prevent overloading the HA implants irradiated after implantation and pay utmost attention to conditions around the bone-implant contact. (author)

Significance of buccopalatal implant position, biotype, platform switching, and pre-implant bone augmentation on the level of the midbuccal mucosa

NARCIS (Netherlands)

Zuiderveld, Elise G; den Hartog, Laurens; Vissink, Arjan; Raghoebar, Gerry M; Meijer, Henny J A

2014-01-01

This study assessed whether buccopalatal implant position, biotype, platform switching, and pre-implant bone augmentation affects the level of the midbuccal mucosa (MBM). Ninety patients with a single-tooth implant in the esthetic zone were included. The level of the MBM was measured on photographs

Dental Implants in an Aged Population: Evaluation of Periodontal Health, Bone Loss, Implant Survival, and Quality of Life.

Science.gov (United States)

Becker, William; Hujoel, Philippe; Becker, Burton E; Wohrle, Peter

2016-06-01

To evaluate aged partially and fully edentulous patients who received dental implants and were maintained over time. Further, to determine how the partially and edentulous ageing populations (65 and above) with dental implants maintain bone levels, proper oral hygiene, and perceive benefits of dental implants. Since 1995, patients receiving dental implants have been prospectively entered into an Access-based computerized program (Triton Tacking System). Patient demographics (age, sex), bone quality, quantity, implant location, and type of surgery have been continuously entered into the database. The database was queried for patients receiving implants (first stage) between 66 and 93 years of age. Thirty-one patients were within this age group. Twenty-five patients returned to the clinic for periodontal and dental implant evaluation. The Periodontal Index was used to evaluate selected teeth in terms of probing depth, bleeding on probing, plaque accumulation, and mobility. Using NIH Image J, radiographs taken at second stage and last examination were measured for changes in interproximal bone levels. Once identified, each patient anomalously filled out an abbreviated quality of health life form. Due to small sample size, descriptive statistics were used to compare clinical findings. Fifteen males ranging from 78 to 84 (mean age 84 years) years and 16 females from 66 to 93 (mean age 83 years) (age range 66-93) were contacted by phone or mail and asked to return to our office for a re-examination. For this group, the first dental implants were placed in 1996 (n = initial two implants) and continuously recorded through 2013 (n = last seven implants). Thirty-one patients received a total of 84 implants. Two patients were edentulous, and the remaining were partially edentulous. Four implants were lost. Between implant placement and 6- to 7-year interval, 13 patients with 40 implants had a cumulative survival rate of 94.6%. Of the original group (n = 33), three

Oral health-related quality of life changes after placement of immediately loaded single implants in healed alveolar ridges or extraction sockets: a 5-year prospective follow-up study.

Science.gov (United States)

Raes, Stefanie; Raes, Filiep; Cooper, Lyndon; Giner Tarrida, Luis; Vervaeke, Stijn; Cosyn, Jan; De Bruyn, Hugo

2017-06-01

The impact of single implants on oral health-related quality of life (OHRQoL) is scarcely investigated, especially when combined with immediate placement and loading in extraction sockets. The aim was to describe prospectively the changes of OHRQoL with single implants placed in the esthetic zone in healed ridges or in extraction sockets after 5 years. Ninety-six patients, enrolled at three clinical centers, received 102 single implants placed in a healed ridge (n = 54 implants/50 patients) or in extraction sockets (n = 48 implants/46 patients). Implants were immediately provisionalized, and permanent crowns were cemented after 12 weeks. Oral health impact profile questionnaires (OHIP-14) were completed before surgery, after 1 (provisional crown), 6 (permanent crown), 12 and 60 months, respectively. The overall OHIP-14 score pertains to seven domains with two items each and was assessed on a Likert scale of 0-4 (0 = never and 4 = very often). The evolution of the total OHIP-14 score and changes within all OHIP domains over time and between groups were assessed with a linear mixed-effect model analysis. After 5 years, overall implant survival was 98%. The total OHIP-14 score for both groups combined decreased from 0.50 at baseline to 0.17 at 6 months (P < 0.001), indicative of improvement. For both groups, this remained stable up to 5 years (P = 0.41). However, after 5 years, the total OHIP-14 score revealed a statistically significantly higher improvement in the healed group compared with the extraction group (P = 0.027). Missing a single tooth in the maxillary esthetic zone leads to limited OHRQoL problems as reflected by a low overall OHIP score. However, OHRQoL improves less in the extraction group, reflecting that replacing a missing tooth is perceived as more beneficial than replacing a present tooth. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of cyclic load on vertical misfit of prefabricated and cast implant single abutment

OpenAIRE

de Jesus Tavarez, Rudys Rodolfo; Bonachela, Wellington Cardoso; Xible, Anuar Antônio

2011-01-01

OBJECTIVES: The purpose of this in vitro study was to evaluate misfit alterations at the implant/abutment interface of external and internal connection implant systems when subjected to cyclic loading. MATERIAL AND METHODS: Standard metal crowns were fabricated for 5 groups (n=10) of implant/abutment assemblies: Group 1, external hexagon implant and UCLA cast-on premachined abutment; Group 2, internal hexagon implant and premachined abutment; Group 3, internal octagon implant and prefabricate...

Measurement of distances between anatomical structures using a translating stage with mounted endoscope

Science.gov (United States)

Kahrs, Lueder A.; Blachon, Gregoire S.; Balachandran, Ramya; Fitzpatrick, J. Michael; Labadie, Robert F.

2012-02-01

During endoscopic procedures it is often desirable to determine the distance between anatomical features. One such clinical application is percutaneous cochlear implantation (PCI), which is a minimally invasive approach to the cochlea via a single, straight drill path and can be achieved accurately using bone-implanted markers and customized microstereotactic frame. During clinical studies to validate PCI, traditional open-field cochlear implant surgery was performed and prior to completion of the surgery, a customized microstereotactic frame designed to achieve the desired PCI trajectory was attached to the bone-implanted markers. To determine whether this trajectory would have safely achieved the target, a sham drill bit is passed through the frame to ensure that the drill bit would reach the cochlea without damaging vital structures. Because of limited access within the facial recess, the distances from the bit to anatomical features could not be measured with calipers. We hypothesized that an endoscope mounted on a sliding stage that translates only along the trajectory, would provide sufficient triangulation to accurately measure these distances. In this paper, the design, fabrication, and testing of such a system is described. The endoscope is mounted so that its optical axis is approximately aligned with the trajectory. Several images are acquired as the stage is moved, and threedimensional reconstruction of selected points allows determination of distances. This concept also has applicability in a large variety of rigid endoscopic interventions including bronchoscopy, laparoscopy, and sinus endoscopy.

Surgical Templates for Dental Implant Positioning; Current ...

African Journals Online (AJOL)

prosthodontics; however, designing an implant‑supported prosthesis with function .... template where a provisional fixed restoration bridges the implant site. Pesun and ... in single implant therapy or short‑span implant‑supported prostheses.

High peak-power kilohertz laser system employing single-stage multi-pass amplification

Science.gov (United States)

Shan, Bing; Wang, Chun; Chang, Zenghu

2006-05-23

The present invention describes a technique for achieving high peak power output in a laser employing single-stage, multi-pass amplification. High gain is achieved by employing a very small "seed" beam diameter in gain medium, and maintaining the small beam diameter for multiple high-gain pre-amplification passes through a pumped gain medium, then leading the beam out of the amplifier cavity, changing the beam diameter and sending it back to the amplifier cavity for additional, high-power amplification passes through the gain medium. In these power amplification passes, the beam diameter in gain medium is increased and carefully matched to the pump laser's beam diameter for high efficiency extraction of energy from the pumped gain medium. A method of "grooming" the beam by means of a far-field spatial filter in the process of changing the beam size within the single-stage amplifier is also described.

Effect of cyclic load on vertical misfit of prefabricated and cast implant single abutment

Science.gov (United States)

DE JESUS TAVAREZ, Rudys Rodolfo; BONACHELA, Wellington Cardoso; XIBLE, Anuar Antônio

2011-01-01

Objective The purpose of this in vitro study was to evaluate misfit alterations at the implant/abutment interface of external and internal connection implant systems when subjected to cyclic loading. Material and Methods Standard metal crowns were fabricated for 5 groups (n=10) of implant/abutment assemblies: Group 1, external hexagon implant and UCLA cast-on premachined abutment; Group 2, internal hexagon implant and premachined abutment; Group 3, internal octagon implant and prefabricated abutment; Group 4, external hexagon implant and UCLA cast-on premachined abutment; and Group 5, external hexagon implant and Ceraone abutment. For groups 1, 2, 3 and 5, the crowns were cemented on the abutments and in group 4 crowns were screwed directly on the implant. The specimens were subjected to 500,000 cycles at 19.1 Hz of frequency and non-axial load of 133 N in a MTS 810 machine. The vertical misfit (μm) at the implant/abutment interface was evaluated before (B) and after (A) application of the cyclic loading. Data were analyzed statistically by using two-away ANOVA and Tukey’s post-hoc test (pabutment connection may develop a role on the vertical misfit at the implant/abutment interface. PMID:21437464

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

Theoretical evaluation of the efficiency of gas single-stage reciprocating compressor medium pressure units

Science.gov (United States)

Busarov, S. S.; Vasil'ev, V. K.; Busarov, I. S.; Titov, D. S.; Panin, Ju. N.

2017-08-01

Developed earlier and tested in such working fluid as air, the technology of calculating the operating processes of slow-speed long-stroke reciprocating stages let the authors to obtain successful results concerning compression of gases to medium pressures in one stage. In this connection, the question of the efficiency of the application of slow-speed long-stroke stages in various fields of technology and the national economy, where the working fluid is other gas or gas mixture, is topical. The article presents the results of the efficiency evaluation of single-stage compressor units on the basis of such stages for cases when ammonia, hydrogen, helium or propane-butane mixture is used as the working fluid.

125I implantation combined with chemotherapy for treatment of local recurrent stage Ⅲ non-small cell lung cancer

International Nuclear Information System (INIS)

Luo Honglei; Yu Xiaojuan; Li Jin; Chen Xiaofei; He Jingdong

2013-01-01

Objective: To investigate the associated effect of 125 I implantation plus chemotherapy in local recurrent stage Ⅲ NSCLC patients. Methods: From January 2006 to January 2009, 34 patients documented with local recurrent stage Ⅲ NSCLC were divided into two groups by random number table. The treatment group was treated with 125 I permanent implantation combined with DP regimen (docetaxel 60 mg/m 2 + cisplatinum 75 mg/m 2 ), while the control group received only DP chemotherapy. According to the TPS, the treatment group received CT-guided percutaneous implantation of 125 I seeds with a particle activity of 2.22 ×10 7 -2.59 × 10 7 Bq. The prescribed dose was in the range of 90-110 Gy and the postoperatively matched peripheral dose (mPD) and D 90 were verified by TPS. The control group received a DP chemotherapy regime for 4 cycles after the procedure. This study was approved by the ethics committee,and all patients signed informed consents. The follow up time was up to disease progression. Kaplan-Meier survival analysis was used to describe the local lesion control (LLC) time and progression free survival (PFS). Log-rank test was used in the comparison of the survival rates between the two groups. Fisher's exact test was used to analyze the differences of CR rate and recent efficiency between two groups. Results: In the treatment group, postoperative mPD was 93.9-130.4 (M 116.7) Gy, and D 90 was 103.6-148.2 (M 130.6) Gy. The LLC time was 4.7 to 24.0 months with a median of 11.6 (95% CI: 8.7-14.6) months. In two cases, there was no recurrence during the follow-up time of 24 months.PFS was 4.7 to 24.0 months with a median of 10.5 (95% CI: 7.4-13.6) months. The recent effective rate of the treatment group was 64.7% (11/17).CR, PR, SD and PD were 41.2% (7/17), 23.5% (4/17), 23.5% (4/17) and 11.8% (2/17), respectively. In the control group, the LLC time was 4.5 to 11.4 months with a median of 7.5 (95 % CI: 6.7-8.3) months, and the median of PFS was 6.5 (4

Synthesis of graphene by MEVVA source ion implantation

International Nuclear Information System (INIS)

Ying, J.J.; Xiao, X.H.; Dai, Z.G.; Wu, W.; Li, W.Q.; Mei, F.; Cai, G.X.; Ren, F.; Jiang, C.Z.

2013-01-01

Ion implantation provides a new synthesis route for graphene, and few-layered graphene synthesis by ion implantation has been reported. Here we show the synthesis of a single layer of high-quality graphene by Metal Vapor Vacuum Arc (MEVVA) source ion implantation. Polycrystalline nickel and copper thin films are implanted with MEVVA source carbon ions at 40 kV, followed by high-temperature thermal annealing and quenching. A Raman spectrum is applied to probe the quality and thickness of the prepared graphene. A single layer of high-quality graphene is grown on the nickel films, but not on the copper films. The growth mechanisms on the nickel and copper films are explained. MEVVA source ion implantation has been widely applied in industrial applications, demonstrating that this synthesis method can be generalized for industrial production

Mass-transfer in extraction and reextraction as a single-stage process

International Nuclear Information System (INIS)

Rodriguez del Cerro, M.; Trilleros, J.A.; Otero de la Gandara, J.L.

1987-01-01

The rate of mass transfer between water and naftenic acid and threebutilphosphate in kerosen are studied in the two possibilities to or from water. The two insoluble phases are brought in to intimate contact with dispersed phase droplets, in a single-stage process. The evolution of the equilibrium distribution of solute is taken in consideration. (author)

First report of a permanent breast 103Pd seed implant as adjuvant radiation treatment for early-stage breast cancer

International Nuclear Information System (INIS)

Pignol, Jean-Philippe; Keller, Brian; Rakovitch, Eileen; Sankreacha, Raxa; Easton, Harry; Que, William

2006-01-01

Purpose: A new technique of adjuvant partial breast irradiation using 103 Pd permanent breast seed implants (PBSI) is presented. The procedure is performed in a single 1-hour session under local anesthesia. Methods and Materials: Patients referred to a single institution for adjuvant radiotherapy after lumpectomy for an infiltrating ductal carcinoma ≤3 cm in diameter, surgical margin ≥2 mm, no extensive in situ carcinoma, no lymphovascular invasion, and minimal or negative lymph node involvement were offered a PBSI. Results: Between May and December 2004, 31 eligible patients underwent CT scan and ultrasound simulations assessing PBSI feasibility. Fifteen were excluded because of feasibility issues, and 16 received PBSI. A minimal peripheral dose of 90 Gy was prescribed to the planning target volume corresponding to the clinical target volume identified on the CT scan plus a margin of 1 cm. The procedure was well tolerated; 56% of the patients reported no pain during the procedure, and 46% of the patients developed National Cancer Institute Common Toxicity Criteria Grade 1 acute reaction. None experienced toxicity Grade 2 or 3. Conclusions: Permanent breast seed implantation seems feasible and well tolerated on these preliminary clinical data and represents an ultimate step in the reduction of treatment fraction for partial breast irradiation

Millijoule Pulse Energy Second Harmonic Generation With Single-Stage Photonic Bandgap Rod Fiber Laser

DEFF Research Database (Denmark)

Laurila, Marko; Saby, Julien; Alkeskjold, Thomas Tanggaard

2011-01-01

In this paper, we demonstrate, for the first time, a single-stage Q-switched single-mode (SM) ytterbium-doped rod fiber laser delivering record breaking pulse energies at visible and UV light. We use a photonic bandgap rod fiber with a mode field diameter of 59μm based on a new distributed...

Esthetic Evaluation of Anterior Single-Tooth Implants with Different Abutment Designs-Patients' Satisfaction Compared to Dentists' Observations.

Science.gov (United States)

Patil, Ratnadeep; Gresnigt, Marco M M; Mahesh, Kavita; Dilbaghi, Anjali; Cune, Marco S

2017-07-01

To correlate patients' satisfaction and dentists' observations regarding two abutment designs used for single crowns in the esthetic zone: a divergent one (control) and a curved one (experimental), with special emphasis on muco-gingival esthetics. Twenty-six patients with nonadjacent missing teeth in the esthetic zone were enrolled in a randomized clinical trial (within-subject comparison). Two implants placed in each were restored using abutments of different geometry. Patients' appreciation was assessed on a visual analog scale (VAS) by recording answers to three questions, and dentists' appreciation was determined by means of the Pink Esthetic Score (PES) at T0 (crown cementation, baseline) and at T12 (1 year post-cementation). ANOVA with post hoc analysis was used to identify differences between groups and at different moments in time. Pearson correlations were calculated between all variables, both at T0 and at T12. No statistically significant differences were found at any time between the control and experimental abutment design, either for the PES or for the VAS score. PES slightly improved after 1 year, as did the VAS rating related to functioning with the implant-crown compared to the natural teeth. All PES and VAS scores demonstrated highly significant correlation. Both patient satisfaction and professional appreciation of muco-gingival conditions after single implant treatment in the esthetic zone were high; however, the curved, experimental abutment design performed no better than the conventional, divergent type. Curved abutment design does not significantly impact crown or gingival esthetics as assessed by PES and VAS scored by dentists and patients, respectively. © 2016 by the American College of Prosthodontists.

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.

A high-order positivity-preserving single-stage single-step method for the ideal magnetohydrodynamic equations

Science.gov (United States)

Christlieb, Andrew J.; Feng, Xiao; Seal, David C.; Tang, Qi

2016-07-01

We propose a high-order finite difference weighted ENO (WENO) method for the ideal magnetohydrodynamics (MHD) equations. The proposed method is single-stage (i.e., it has no internal stages to store), single-step (i.e., it has no time history that needs to be stored), maintains a discrete divergence-free condition on the magnetic field, and has the capacity to preserve the positivity of the density and pressure. To accomplish this, we use a Taylor discretization of the Picard integral formulation (PIF) of the finite difference WENO method proposed in Christlieb et al. (2015) [23], where the focus is on a high-order discretization of the fluxes (as opposed to the conserved variables). We use the version where fluxes are expanded to third-order accuracy in time, and for the fluid variables space is discretized using the classical fifth-order finite difference WENO discretization. We use constrained transport in order to obtain divergence-free magnetic fields, which means that we simultaneously evolve the magnetohydrodynamic (that has an evolution equation for the magnetic field) and magnetic potential equations alongside each other, and set the magnetic field to be the (discrete) curl of the magnetic potential after each time step. In this work, we compute these derivatives to fourth-order accuracy. In order to retain a single-stage, single-step method, we develop a novel Lax-Wendroff discretization for the evolution of the magnetic potential, where we start with technology used for Hamilton-Jacobi equations in order to construct a non-oscillatory magnetic field. The end result is an algorithm that is similar to our previous work Christlieb et al. (2014) [8], but this time the time stepping is replaced through a Taylor method with the addition of a positivity-preserving limiter. Finally, positivity preservation is realized by introducing a parameterized flux limiter that considers a linear combination of high and low-order numerical fluxes. The choice of the free

Breast Implant-Associated Anaplastic Large Cell Lymphoma: Case Report and Review of the Literature.

Science.gov (United States)

Berlin, Eva; Singh, Kunwar; Mills, Christopher; Shapira, Ilan; Bakst, Richard L; Chadha, Manjeet

2018-01-01

We are reporting the case of a 58-year-old woman with history of bilateral silicone breast implants for cosmetic augmentation. At 2-year interval from receiving the breast implants, she presented with swelling of the right breast with associated chest wall mass, effusion around the implant, and axillary lymphadenopathy. Pathology confirmed breast implant-associated anaplastic large cell lymphoma (stage III, T4N2M0, using BIA-ALCL TNM staging and stage IIAE, using Ann-Arbor staging). The patient underwent bilateral capsulectomy and right partial mastectomy with excision of the right breast mass and received adjuvant CHOP chemotherapy and radiation to the right breast and regional nodes. Since completion of multimodality therapy, the patient has sustained remission on both clinical exam and PET/CT scan. We report this case and review of the literature on this rare form of lymphoma.

Induction of congenital malformations in the offspring of male mice treated with X-rays at pre-meiotic and post-meiotic stages

International Nuclear Information System (INIS)

Kirk, K.M.; Lyon, M.F.

1984-01-01

The induction of congenital malformations among the offspring of male mice treated with X-rays at pre-meiotic and post-meiotic stages has been studied in two experiments. Firstly, animals were exposed to varying doses of X-rays and mated at various time intervals, so as to sample spermatozoa, spermatids and spermatogonial stem cells. In the second experiment, only treated spermatogonial stem cells were sampled. One group of males was given a single dose, a second group a fractionated dose and a third group was left unexposed. In the first experiment, induced post-implantation dominant lethality increased with dose, and was highest in week 3, in line with the known greater radiosensitivity of the early spermatid stage. Preimplantation loss also increased with dose and was highest in week 3. There was no clear induction of either pre-implantation or post-implantation loss at spermatogonial stem cell stages. There was a clear induction of congenital malformations at post-meiotic stages. At the two highest doses the early spermatids (15-21 days) appeared more sensitive than spermatozoa, and at this stage the incidence of malformations increased with dose. Expt. 2 showed a statistically significant induction of malformations at both dose levels. The relative sensitivities of male stem cells, post-meiotic stages and mature oocytes to the induction of congenital malformations were reasonably similar to their sensitivities for specific-locus mutations, except that the expected enhancing effect of the fractionation regime used was not seen. (Auth.)

Induction of congenital malformations in the offspring of male mice treated with X-rays at pre-meiotic and post-meiotic stages

Energy Technology Data Exchange (ETDEWEB)

Kirk, K.M.; Lyon, M.F. (Medical Research Council, Harwell (UK). Radiobiological Research Unit)

1984-01-01

The induction of congenital malformations among the offspring of male mice treated with X-rays at pre-meiotic and post-meiotic stages has been studied in two experiments. Firstly, animals were exposed to varying doses of X-rays and mated at various time intervals, so as to sample spermatozoa, spermatids and spermatogonial stem cells. In the second experiment, only treated spermatogonial stem cells were sampled. One group of males was given a single dose, a second group a fractionated dose and a third group was left unexposed. In the first experiment, induced post-implantation dominant lethality increased with dose, and was highest in week 3, in line with the known greater radiosensitivity of the early spermatid stage. Preimplantation loss also increased with dose and was highest in week 3. There was no clear induction of either pre-implantation or post-implantation loss at spermatogonial stem cell stages. There was a clear induction of congenital malformations at post-meiotic stages. At the two highest doses the early spermatids (15-21 days) appeared more sensitive than spermatozoa, and at this stage the incidence of malformations increased with dose. Expt. 2 showed a statistically significant induction of malformations at both dose levels. The relative sensitivities of male stem cells, post-meiotic stages and mature oocytes to the induction of congenital malformations were reasonably similar to their sensitivities for specific-locus mutations, except that the expected enhancing effect of the fractionation regime used was not seen.

A single pre-operative antibiotic dose is as effective as continued antibiotic prophylaxis in implant-based breast reconstruction: A matched cohort study.

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Townley, William A; Baluch, Narges; Bagher, Shaghayegh; Maass, Saskia W M C; O'Neill, Anne; Zhong, Toni; Hofer, Stefan O P

2015-05-01

Infections following implant-based breast reconstruction can lead to devastating consequences. There is currently no consensus on the need for post-operative antibiotics in preventing immediate infection. This study compared two different methods of infection prevention in this group of patients. A retrospective matched cohort study was performed on consecutive women undergoing implant-based breast reconstruction at University Health Network, Toronto (November 2008-December 2012). All patients received a single pre-operative intravenous antibiotic dose. Group A received minimal interventions and Group B underwent maximal prophylactic measures. Patient (age, smoking, diabetes, co-morbidities), oncologic and procedural variables (timing and laterality) were collected. Univariate and multivariate logistic regression were performed to compare outcomes between the two groups. Two hundred and eight patients underwent 647 implant procedures. After matching the two treatment groups by BMI, 94 patients in each treatment group yielding a total of 605 implant procedures were selected for analysis. The two groups were comparable in terms of patient and disease variables. Post-operative wound infection was similar in Group A (n = 11, 12%) compared with Group B (n = 9, 10%; p = 0.8). Univariate analysis revealed only pre-operative radiotherapy to be associated with the development of infection (0.004). Controlling for the effect of radiotherapy, multivariate analysis demonstrated that there was no statistically significant difference between the two methods for infection prevention. Our findings suggest that a single pre-operative dose of intravenous antibiotics is equally as effective as continued antibiotic prophylaxis in preventing immediate infection in patients undergoing implant-based breast reconstructions. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

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-stage

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

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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.

Positional changes of maxillary central incisors following orthodontic treatment using single-crown implants as fixed reference markers

DEFF Research Database (Denmark)

Brahem Ben, Elissa; Holm, Bente; Sonnesen, L

2017-01-01

OBJECTIVES: This follow-up study (1) compares tooth displacement of central incisors in patients with and without pre-implant orthodontic treatment and (2) investigates whether sex, age, or orthodontic retention have an effect on tooth displacement after the insertion of single-crown implants...... during baseline examinations after prosthetic rehabilitation and at the final follow-up examination at least 5 years later. A total of 114 dental casts were digitalized and aligned using a software program to measure changes in the positions of the central incisors. RESULTS: After a follow-up period......, and there were no significant correlations with patient age or sex. CONCLUSION: The majority of patients had minor vertical (60%) or horizontal (67%) tooth displacement of the central incisors (0.25-0.75 mm) after a minimum follow-up period of 5 years. This study found no significant differences in tooth...

The Total Artificial Heart in End-Stage Congenital Heart Disease.

Science.gov (United States)

Villa, Chet R; Morales, David L S

2017-01-01

The development of durable ventricular assist devices (VADs) has improved mortality rates and quality of life in patients with end stage heart failure. While the use of VADs has increased dramatically in recent years, there is limited experience with VAD implantation in patients with complex congenital heart disease (CHD), despite the fact that the number of patients with end stage CHD has grown due to improvements in surgical and medical care. VAD use has been limited in patients with CHD and end stage heart failure due to anatomic (systemic right ventricle, single ventricle, surgically altered anatomy, valve dysfunction, etc.) and physiologic constraints (diastolic dysfunction). The total artificial heart (TAH), which has right and left sided pumps that can be arranged in a variety of orientations, can accommodate the anatomic variation present in CHD patients. This review provides an overview of the potential use of the TAH in patients with CHD.

Single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation in surgical treatment for single-segment lumbar spinal tuberculosis.

Science.gov (United States)

Zeng, Hao; Wang, Xiyang; Zhang, Penghui; Peng, Wei; Liu, Zheng; Zhang, Yupeng

2015-01-01

The aim of this study is to determine the feasibility and efficacy of surgical management of single-segment lumbar spinal tuberculosis (TB) by using single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation. Seventeen cases of single-segment lumbar TB were treated with single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation. The mean follow-up was 36.9 months (range: 24-62 months). The kyphotic angle ranged from 15.2-35.1° preoperatively, with an average measurement of 27.8°. The American Spinal Injury Association (ASIA) score system was used to evaluate the neurological deficits and erythrocyte sedimentation rate (ESR) used to judge the activity of TB. Spinal TB was completely cured in all 17 patients. There was no recurrent TB infection. The postoperative kyphotic angle was 6.6-10.2°, 8.1° in average, and there was no significant loss of the correction at final follow-up. Solid fusion was achieved in all cases. Neurological condition in all patients was improved after surgery. Single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation can be a feasible and effective method the in treatment of single-segment lumbar spinal TB.

A 5-year randomized trial to compare 1 or 2 implants for implant overdentures.

Science.gov (United States)

Bryant, S R; Walton, J N; MacEntee, M I

2015-01-01

The hypothesis of this 5-y randomized clinical trial was that there would be no significant difference in the satisfaction of edentulous participants with removable complete overdentures attached to 1 or 2 mandibular implants. Secondary aims were to test changes in satisfaction between and within the groups from baseline to 5 y and differences between the groups in implant survival and prosthodontic maintenance over 5 y. Each of the 86 participants (mean age, 67 y) was randomly allocated to receive either 1 implant in the midline (group 1) or 2 implants in the canine areas (group 2) attached to a mandibular overdenture opposing a maxillary complete denture. Satisfaction was self-assessed by participants on a visual analog scale at baseline prior to implants, as well as at 2 mo and 1, 3, and 5 y with implant overdentures, whereas implant survival and prosthodontic maintenance were assessed by clinical examination. After 5 y, 29 participants in group 1 and 33 in group 2 were available, with most dropouts due to death. Satisfaction with the implant denture after 5 y was significantly (P overdentures retained by 1 implant or 2 implants. Additional research is required to confirm long-term treatment effectiveness of single-implant dentures and the implications of prosthetic maintenance with implant overdentures (ClinicalTrials.gov: NCT02117856). © International & American Associations for Dental Research 2014.

Effect of crown-to-implant ratio on peri-implant stress: a finite element analysis.

Science.gov (United States)

Verri, Fellippo Ramos; Batista, Victor Eduardo de Souza; Santiago, Joel Ferreira; Almeida, Daniel Augusto de Faria; Pellizzer, Eduardo Piza

2014-12-01

The aim of this study was to evaluate stress distribution in the fixation screws and bone tissue around implants in single-implant supported prostheses with crowns of different heights (10, 12.5, 15 mm - crown-to-implant ratio 1:1, 1.25:1, 1.5:1, respectively). It was designed using three 3-D models. Each model was developed with a mandibular segment of bone block including an internal hexagon implant supporting a screw-retained, single metal-ceramic crown. The crown height was set at 10, 12.5, and 15 mm with crown-to-implant ratio of 1:1, 1.25:1, 1.5:1, respectively. The applied forces were 200N (axial) and 100 N (oblique). The increase of crown height showed differences with the oblique load in some situations. By von Mises' criterion, a high stress area was concentrated at the implant/fixation screw and abutment/implant interfaces at crown-to-implant ratio of 1:1, 1.25:1, 1.5:1, respectively. Using the maximum principal criteria, the buccal regions showed higher traction stress intensity, whereas the distal regions showed the largest compressive stress in all models. The increase of C/I ratio must be carefully evaluated by the dentist since the increase of this C/I ratio is proportional to the increase of average stress for both screw fixation (C/I 1:1 to 1:1.25 ratio=30.1% and C/I 1:1 to 1:1.5 ratio=46.3%) and bone tissue (C/I 1:1 to 1:1.25 ratio=30% and C/I 1:1 to 1:1.5 ratio=51.5%). Copyright © 2014 Elsevier B.V. All rights reserved.

Significantly enhanced visible light response in single TiO2 nanowire by nitrogen ion implantation

Science.gov (United States)

Wu, Pengcheng; Song, Xianyin; Si, Shuyao; Ke, Zunjian; Cheng, Li; Li, Wenqing; Xiao, Xiangheng; Jiang, Changzhong

2018-05-01

The metal-oxide semiconductor TiO2 shows enormous potential in the field of photoelectric detection; however, UV-light absorption only restricts its widespread application. It is considered that nitrogen doping can improve the visible light absorption of TiO2, but the effect of traditional chemical doping is far from being used for visible light detection. Herein, we dramatically broadened the absorption spectrum of the TiO2 nanowire (NW) by nitrogen ion implantation and apply the N-doped single TiO2 NW to visible light detection for the first time. Moreover, this novel strategy effectively modifies the surface states and thus regulates the height of Schottky barriers at the metal/semiconductor interface, which is crucial to realizing high responsivity and a fast response rate. Under the illumination of a laser with a wavelength of 457 nm, our fabricated photodetector exhibits favorable responsivity (8 A W-1) and a short response time (0.5 s). These results indicate that ion implantation is a promising method in exploring the visible light detection of TiO2.

Ventricular assist device use in single ventricle congenital heart disease.

Science.gov (United States)

Carlo, Waldemar F; Villa, Chet R; Lal, Ashwin K; Morales, David L

2017-11-01

As VAD have become an effective therapy for end-stage heart failure, their application in congenital heart disease has increased. Single ventricle congenital heart disease introduces unique physiologic challenges for VAD use. However, with regard to the mixed clinical results presented within this review, we suggest that patient selection, timing of implant, and center experience are all important contributors to outcome. This review focuses on the published experience of VAD use in single ventricle patients and details physiologic challenges and novel approaches in this growing pediatric and adult population. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Softening the ultra-stiff: Controlled variation of Young’s modulus in single-crystal diamond by ion implantation

International Nuclear Information System (INIS)

Battiato, A.; Lorusso, M.; Bernardi, E.; Picollo, F.; Bosia, F.; Ugues, D.; Zelferino, A.; Damin, A.; Baima, J.

2016-01-01

A combined experimental and numerical study on the variation of the elastic properties of defective single-crystal diamond is presented for the first time, by comparing nano-indentation measurements on MeV-ion-implanted samples with multi-scale modeling consisting of both ab initio atomistic calculations and meso-scale Finite Element Method (FEM) simulations. It is found that by locally introducing defects in the 2 × 10 18 –5 × 10 21  cm −3 density range, a significant reduction of Young’s modulus, as well as of density, can be induced in the diamond crystal structure without incurring in the graphitization of the material. Ab initio atomistic simulations confirm the experimental findings with a good degree of confidence. FEM simulations are further employed to verify the consistency of measured deformations with a stiffness reduction, and to derive strain and stress levels in the implanted region. Combining these experimental and numerical results, we also provide insight into the mechanism responsible for the depth dependence of the graphitization threshold in diamond. This work prospects the possibility of achieving accurate tunability of the mechanical properties of single-crystal diamond through defect engineering, with significant technological applications, e.g. the fabrication and control of the resonant frequency of diamond-based micromechanical resonators.

Breast Implant-Associated Anaplastic Large Cell Lymphoma: Case Report and Review of the Literature

Directory of Open Access Journals (Sweden)

Eva Berlin

2018-01-01

Full Text Available We are reporting the case of a 58-year-old woman with history of bilateral silicone breast implants for cosmetic augmentation. At 2-year interval from receiving the breast implants, she presented with swelling of the right breast with associated chest wall mass, effusion around the implant, and axillary lymphadenopathy. Pathology confirmed breast implant-associated anaplastic large cell lymphoma (stage III, T4N2M0, using BIA-ALCL TNM staging and stage IIAE, using Ann-Arbor staging. The patient underwent bilateral capsulectomy and right partial mastectomy with excision of the right breast mass and received adjuvant CHOP chemotherapy and radiation to the right breast and regional nodes. Since completion of multimodality therapy, the patient has sustained remission on both clinical exam and PET/CT scan. We report this case and review of the literature on this rare form of lymphoma.

A reliable method for the counting and control of single ions for single-dopant controlled devices

International Nuclear Information System (INIS)

Shinada, T; Kurosawa, T; Nakayama, H; Zhu, Y; Hori, M; Ohdomari, I

2008-01-01

By 2016, transistor device size will be just 10 nm. However, a transistor that is doped at a typical concentration of 10 18 atoms cm -3 has only one dopant atom in the active channel region. Therefore, it can be predicted that conventional doping methods such as ion implantation and thermal diffusion will not be available ten years from now. We have been developing a single-ion implantation (SII) method that enables us to implant dopant ions one-by-one into semiconductors until the desired number is reached. Here we report a simple but reliable method to control the number of single-dopant atoms by detecting the change in drain current induced by single-ion implantation. The drain current decreases in a stepwise fashion as a result of the clusters of displaced Si atoms created by every single-ion incidence. This result indicates that the single-ion detection method we have developed is capable of detecting single-ion incidence with 100% efficiency. Our method potentially could pave the way to future single-atom devices, including a solid-state quantum computer

Adaptive kanban control mechanism for a single-stage hybrid system

Science.gov (United States)

Korugan, Aybek; Gupta, Surendra M.

2002-02-01

In this paper, we consider a hybrid manufacturing system with two discrete production lines. Here the output of either production line can satisfy the demand for the same type of product without any penalties. The interarrival times for demand occurrences and service completions are exponentially distributed i.i.d. variables. In order to control this type of manufacturing system we suggest a single stage pull type control mechanism with adaptive kanbans and state independent routing of the production information.

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

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.

Polymeric composite devices for localized treatment of early-stage breast cancer.

Directory of Open Access Journals (Sweden)

Kwabena Kan-Dapaah

Full Text Available For early-stage breast cancers mastectomy is an aggressive form of treatment. Therefore, there is a need for new treatment strategies that can enhance the use of lumpectomy by eliminating residual cancer cells with limited side effects to reduce local recurrence. Although, various radiotherapy-based methods have been developed, residual cells are found in 20-55% of the time at the first operation. Furthermore, some current treatment methods result in poor cosmesis. For the last decade, the authors have been exploring the use of polymeric composite materials in single and multi-modal implantable biomedical devices for post-operative treatment of breast cancer. In this paper, the concept and working principles of the devices, as well as selected results from experimental and numerical investigations, are presented. The results show the potential of the biomedical implants for cancer treatment.

Influence of two barrier membranes on staged guided bone regeneration and osseointegration of titanium implants in dogs: part 1. Augmentation using bone graft substitutes and autogenous bone.

Science.gov (United States)

Schwarz, Frank; Mihatovic, Ilja; Golubovic, Vladimir; Hegewald, Andrea; Becker, Jürgen

2012-01-01

To assess the influence of two barrier membranes and two bone graft substitutes mixed with autogenous bone (AB) on staged guided bone regeneration and osseointegration of titanium implants in dogs. Four saddle-type defects each were prepared in the upper jaw of six fox hounds and randomly filled with a natural bone mineral (NBM)+AB and a biphasic calcium phosphate (SBC)+AB and allocated to either an in situ gelling polyethylene glycol (PEG) or a collagen membrane (CM). At 8 weeks, modSLA titanium implants were inserted and left to heal in a submerged position. At 8+2 weeks, dissected blocks were processed for histomorphometrical analysis (e.g., treated area [TA], bone-to-implant contact [BIC]). The mean TA values (mm(2) ) and BIC values (%) tended to be higher in the PEG groups(TA: NBM+AB [10.4 ± 2.5]; SBC+AB [10.4 ± 5.8]/BIC: NBM+AB [86.4 ± 20.1]; SBC+AB [80.1 ± 21.5]) when compared with the corresponding CM groups (TA: NBM+AB [9.7 ± 4.8]; SBC+AB [7.8 ± 4.3]/BIC: NBM+AB [71.3 ± 20.8]; SBC+AB [72.4 ± 20.3]). A significant difference was observed for the mean TA values in the SBC+AB groups. It was concluded that all augmentation procedures investigated supported bone regeneration and staged osseointegration of modSLA titanium implants. However, the application of PEG may be associated with increased TA values. © 2011 John Wiley & Sons A/S.

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.

New current control based MPPT technique for single stage grid connected PV systems

International Nuclear Information System (INIS)

Jain, Sachin; Agarwal, Vivek

2007-01-01

This paper presents a new maximum power point tracking algorithm based on current control for a single stage grid connected photovoltaic system. The main advantage of this algorithm comes from its ability to predict the approximate amplitude of the reference current waveform or power that can be derived from the PV array with the help of an intermediate variable β. A variable step size for the change in reference amplitude during initial tracking helps in fast tracking. It is observed that if the reference current amplitude is greater than the array capacity, the system gets unstable (i.e. moves into the positive slope region of the p-v characteristics of the array). The proposed algorithm prevents the PV system from entering the positive slope region of the p-v characteristics. It is also capable of restoring stability if the system goes unstable due to a sudden environmental change. The proposed algorithm has been tested on a new single stage grid connected PV configuration recently developed by the authors to feed sinusoidal current into the grid. The system is operated in a continuous conduction mode to realize advantages such as low device current stress, high efficiency and low EMI. A fast MPPT tracker with single stage inverter topology operating in CCM makes the overall system highly efficient. Specific cases of the system, operating in just discontinuous current mode and discontinuous current mode and their relative merits and demerits are also discussed

Compressed gas combined single- and two-stage light-gas gun

Science.gov (United States)

Lamberson, L. E.; Boettcher, P. A.

2018-02-01

With more than 1 trillion artificial objects smaller than 1 μm in low and geostationary Earth orbit, space assets are subject to the constant threat of space debris impact. These collisions occur at hypervelocity or speeds greater than 3 km/s. In order to characterize material behavior under this extreme event as well as study next-generation materials for space exploration, this paper presents a unique two-stage light-gas gun capable of replicating hypervelocity impacts. While a limited number of these types of facilities exist, they typically are extremely large and can be costly and dangerous to operate. The design presented in this paper is novel in two distinct ways. First, it does not use a form of combustion in the first stage. The projectile is accelerated from a pressure differential using air and inert gases (or purely inert gases), firing a projectile in a nominal range of 1-4 km/s. Second, the design is modular in that the first stage sits on a track sled and can be pulled back and used in itself to study lower speed impacts without any further modifications, with the first stage piston as the impactor. The modularity of the instrument allows the ability to investigate three orders of magnitude of impact velocities or between 101 and 103 m/s in a single, relatively small, cost effective instrument.

EGF increases expression and activity of PAs in preimplantation rat embryos and their implantation rate

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Har-Vardi Iris

2007-01-01

Full Text Available Abstract Background Embryo implantation plays a major role in embryogenesis and the outcome of pregnancy. Plasminogen activators (PAs have been implicated in mammalian fertilization, early stages of development and embryo implantation. As in-vitro developing embryos resulted in lower implantation rate than those developed in-vivo we assume that a reduced PAs activity may be involved. In the present work we studied the effect of EGF on PAs activity, quantity and embryo implantation. Methods Zygotes were flushed from rat oviducts on day one of pregnancy and grown in-vitro in R1ECM supplemented with EGF (10 ng/ml and were grown up to the blastocyst stage. The control groups were grown in the same medium without EGF. The distribution and quantity of the PAs were examined using fluorescence immunohistochemistry followed by measurement of PAs activity using the chromogenic assay. Implantation rate was studied using the embryo donation model. Results PAs distribution in the embryos was the same in EGF treated and untreated embryos. Both PAs were localized in the blastocysts' trophectoderm, supporting the assumption that PAs play a role in the implantation process in rats. EGF increased the quantity of uPA at all stages studied but the 8-cell stage as compared with controls. The tissue type PA (tPA content was unaffected except the 8-cell stage, which was increased. The activity of uPA increased gradually towards the blastocyst stage and more so due to the presence of EGF. The activity of tPA did not vary with the advancing developmental stages although it was also increased by EGF. The presence of EGF during the preimplantation development doubled the rate of implantation of the treated group as compared with controls.

The Incidence of Complications in Single-stage Endoscopic Stone Removal for Patients with Common Bile Duct Stones: A Propensity Score Analysis.

Science.gov (United States)

Saito, Hirokazu; Kadono, Yoshihiro; Kamikawa, Kentaro; Urata, Atsushi; Imamura, Haruo; Matsushita, Ikuo; Kakuma, Tatsuyuki; Tada, Shuji

2018-02-15

Objective Single-stage endoscopic stone removal for choledocholithiasis is an advantageous approach because it is associated with a shorter hospital stay; however, few studies have reported the incidence of complications related to this procedure in detail. The aim of this study was to examine the incidence of complications and efficacy of this procedure. Methods This retrospective study investigated the incidence of complications in 345 patients with naive papilla who underwent therapeutic endoscopic retrograde cholangiopancreatography (ERCP) for choledocholithiasis at three institutions between April 2014 and March 2016 by a propensity score analysis. The efficacy of single-stage endoscopic stone removal was assessed based on a hospital stay of within 7 days and the number of ERCP attempts. Results Among 114 patients who underwent single-stage endoscopic stone removal, 15 patients (13.2%) experienced complications. Among the remaining 231 patients in the two-stage endoscopic stone removal group, complications were observed in 17 patients (7.4%). The propensity score analysis, which was adjusted for confounding factors, revealed that single-stage endoscopic stone removal was not a significant risk factor for complications (p=0.52). In patients in whom >10 min was required for deep cannulation, single-stage endoscopic stone removal was not a significant risk factor for complications in the propensity score analysis (p=0.37). In the single-stage group, the proportion of patients with a hospital stay of within 7 days was significantly higher and the number of ERCP attempts was significantly lower in comparison to the two-stage group (p <0.0001 and <0.0001, respectively). Conclusion Single-stage endoscopic stone removal did not increase the incidence of complications associated with ERCP and was effective for reducing the hospital stay and the number of ERCP attempts.

A tetrad of bicuspid aortic valve association: A single-stage repair

Science.gov (United States)

Barik, Ramachandra; Patnaik, A. N.; Mishra, Ramesh C.; Kumari, N. Rama; Gulati, A. S.

2012-01-01

We report a 27 years old male who presented with a combination of both congenital and acquired cardiac defects. This syndrome complex includes congenital bicuspid aortic valve, Seller's grade II aortic regurgitation, juxta- subclavian coarctation, stenosis of ostium of left subclavian artery and ruptured sinus of Valsalva aneurysm without any evidence of infective endocarditis. This type of constellation is extremely rare. Neither coarctation of aorta with left subclavian artery stenosis nor the rupture of sinus Valsalva had a favorable pathology for percutaneus intervention. Taking account into morbidity associated with repeated surgery and anesthesia patient underwent a single stage surgical repair of both the defects by two surgical incisions. The approaches include median sternotomy for rupture of sinus of Valsalva and lateral thoracotomy for coarctation with left subclavian artery stenosis. The surgery was uneventful. After three months follow up echocardiography showed mild residual gradient across the repaired coarctation segment, mild aortic regurgitation and no residual left to right shunt. This patient is under follow up. This is an extremely rare case of single stage successful repair of coarctation and rupture of sinus of Valsalva associated with congenital bicuspid aortic valve. PMID:22629035

Large Conization and Laparoendoscopic Single-Port Pelvic Lymphadenectomy in Early-Stage Cervical Cancer for Fertility Preservation

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Polat Dursun

2013-01-01

Full Text Available Fertility preservation in early-stage cervical cancer is a hot topic in gynecologic oncology. Although radical vaginal trachelectomy (RVT is suggested as a fertility preserving approach, there are some serious concerns like cervical stenosis, second trimester loss, preterm delivery in survivors, and lack of residual tumor in the majority of the surgical specimens. Therefore, less radical surgical operations have been proposed in early-stage cervical carcinomas. On the other hand, single-incision laparoscopic surgery (SILS is an evolving endoscopic approach for minimal access surgery. In this report, we present a case with early-stage cervical cancer who wishes to preserve fertility. We successfully performed single-port pelvic lymphadenectomy and large conization to preserve fertility potential of the patient. We think that combination of less radical approach like conization and single-port pelvic lymphadenectomy might be less minimally invasive and is still an effective surgical approach in well-selected cases with cervical carcinomas. Incorporation of single-port laparoscopy into the minimally invasive fertility sparing management of the cervical cancer will improve patients outcome with less complications and better cosmesis. Further studies are needed to reach a clear conclusion.

MRI of hip prostheses using single-point methods : in vitro studies towards the artifact-free imaging of individuals with metal implants

NARCIS (Netherlands)

Ramos Cabrer, P.; Duynhoven, van J.P.M.; Toorn, van der A.; Nicolaij, K.

2004-01-01

Use of magnetic resonance imaging (MRI) in individuals with orthopedic implants is limited because of the large distortions caused by metallic components. As a possible solution for this problem, we suggest the use of single-point imaging (SPI) methods, which are immune to the susceptibility

Immediate versus Delayed Treatment in the Anterior Maxilla Using Single Implants with a Laser-Microtextured Collar: 3-Year Results of a Case Series on Hard- and Soft-Tissue Response and Esthetics.

Science.gov (United States)

Guarnieri, Renzo; Belleggia, Fabrizio; Grande, Maurizio

2016-02-01

To compare peri-implant marginal bone loss, soft tissue response, and esthetics following single immediate implant treatment (IIT) and delayed implant treatment (DIT) in the esthetic zone of the maxilla in well-selected patients. Adequate bone volume and ideal soft tissue level/contour were considered requirements for implant therapy, with additional prerequisites for IIT of residual alveolar bone wall integrity and a thick gingival biotype. IIT included immediate placement and provisionalization, while DIT included extraction socket preservation followed by implant placement and provisionalization 4 months later. Cortical bone levels and peri-implant mucosal conditions were evaluated at regular intervals. The esthetic outcome was objectively rated after 3 years using the pink esthetic score (PES) and white esthetic score (WES). Twelve patients received an immediate Laser-Lok® implant, and 13 patients received a delayed Laser-Lok® implant. No significant differences were found between the study groups regarding survival rate (100%). The mean bone level from the implant/abutment interface was 0.35 ± 0.18 mm for IIT and 0.42 ± 0.21 mm for DIT after 3 years (p > 0.05). Mesial and distal papillae remained stable over time in DIT. A tendency for regrowth of mesial and distal papillae was found following IIT (p esthetics, DIT and IIT with single Laser-Lok® implants in the anterior maxilla are comparable and predictable options for well-selected patients. © 2015 by the American College of Prosthodontists.

Horizontal stability of connective tissue grafts at the buccal aspect of single implants: a 1-year prospective case series.

Science.gov (United States)

De Bruyckere, Thomas; Eghbali, Aryan; Younes, Faris; De Bruyn, Hugo; Cosyn, Jan

2015-09-01

To clinically evaluate the horizontal stability of a connective tissue graft (CTG) at the buccal aspect of single implants (1); to compare actual gingival thickness between thin and thick gingival biotype (2). Periodontally healthy non-smoking patients with a single implant in the anterior maxilla (15-25) were selected for a prospective case series. All demonstrated a horizontal alveolar defect and were in need of contour augmentation by means of CTG for aesthetic reasons. Patients were enrolled 3 months after implant surgery and had been provided with a provisional screw-retained crown. CTG was inserted in the buccal mucosa via the envelope technique using one intrasulcular incision. An ultrasonic device was used to evaluate mucosal thickness (MT) at the buccal aspect. MT was assessed at t0 (before CTG), t1 (immediately after CTG), t2 (2 weeks after CTG = suture removal), t3 (3 months after CTG = permanent crown installation) and t4 (1 year after implant placement). The gingival biotype was categorized as thin or thick based on the transparency of a periodontal probe through the soft tissues while probing the buccal sulcus of the contra-lateral tooth. Gingival thickness (GT) was measured at the contra-lateral tooth using the same ultrasonic device. Thirty-seven patients (19 men, 18 women; mean age 38) met the selection criteria and consented to the treatment. Mean soft tissue gain immediately after CTG was on average 1.07 mm (SD 0.49). What remained of this tissue gain after 1 year was on average 0.97 mm (SD 0.48; 90.5%). Hence, mean soft tissue loss amounted to 0.10 mm (SD 0.23; 9.5%; p = 0.015) with no significant difference between patients with a thin or thick biotype (p ≥ 0.290). Patients with a thin biotype had a mean GT of 1.02 mm (SD 0.21), whereas GT was on average 1.32 mm (SD 0.31) in subjects with a thick biotype (p = 0.004). Connective tissue graft substantially thickens the peri-implant mucosa with acceptable stability over a 1-year period. © 2015

[Application of endosseous screw implants. Indications and planning].

Science.gov (United States)

Pajarola, G F; Sailer, H F

1991-01-01

To achieve long term positive results for endosseous dental implants, three points have to be considered: the osséointegration, the correct indication and the suprastructural planification designed for the spécific type of implant. If the surgery part is done by a different practitioner as the prosthetic part, tight coworking for planning is necessary and the responsibility in each step has to be cleared in advance. The planification in implant cases is divided into three stages: clearing of contraindications, choice of the suprastructure, and the surgery planning. Aids for exact localisation of the implants are presented.

Configuration and mobility of hydrogen implanted in aluminium

International Nuclear Information System (INIS)

Bugeat, J.P.; Chami, A.C.; Ligeon, E.

1976-01-01

Localization methods through channeling and nuclear reaction analysis using low energy ion beam were applied to the study of deuterium and hydrogen implanted in aluminium single crystals. It was shown that implanted hydrogen occupies a tetrahedral site in the lattice as far as the implantation temperature is lower than 175K. This fact is interpreted by considering an interaction between hydrogen and monovacancies created during the implantation [fr

Lithium ion implantation effects in MgO (100)

NARCIS (Netherlands)

van Huis, MA; Fedorov, AV; van Veen, A; Labohm, F; Schut, H; Mijnarends, PE; Kooi, BJ; De Hosson, JTM; Triftshauser, W; Kogel, G; Sperr, P

2001-01-01

Single crystals of MgO (100) were implanted with 10(16) (6)Li ions cm(-2) at an energy of 30 keV. After ion implantation the samples were annealed isochronally in air at temperatures up to 1200K. After implantation and after each annealing step, the defect evolution was monitored with optical

Grid Integration of Single Stage Solar PV System using Three-level Voltage Source Converter

Science.gov (United States)

Hussain, Ikhlaq; Kandpal, Maulik; Singh, Bhim

2016-08-01

This paper presents a single stage solar PV (photovoltaic) grid integrated power generating system using a three level voltage source converter (VSC) operating at low switching frequency of 900 Hz with robust synchronizing phase locked loop (RS-PLL) based control algorithm. To track the maximum power from solar PV array, an incremental conductance algorithm is used and this maximum power is fed to the grid via three-level VSC. The use of single stage system with three level VSC offers the advantage of low switching losses and the operation at high voltages and high power which results in enhancement of power quality in the proposed system. Simulated results validate the design and control algorithm under steady state and dynamic conditions.

Dual-ion implantation into GaAs

International Nuclear Information System (INIS)

Sealy, B.J.; Bell, E.C.; Surridge, R.K.; Stephens, K.G.; Ambridge, T.; Heckingbottom, R.

1976-01-01

A variety of dual implants have been carried out to test the theory of Ambridge and Heckingbottom (Ambridge, T. and Heckingbottom, R., 1973, Radiat. Effects, vol. 17, 31). After annealing at 700 0 C or 750 0 C a significant enhancement of electrical activity compared with single-ion implants has been obtained for (Ga + Se) and (Sn + Se) implants but the degree of enhancement is dose dependent. The results imply that the dual implantation process is more complex than predicted by the theory and the electrical activity measured seems to be dominated by residual, compensating damage. (author)

Hydrogen interstitial in H-ion implanted ZnO bulk single crystals: Evaluation by elastic recoil detection analysis and electron paramagnetic resonance

Energy Technology Data Exchange (ETDEWEB)

Kaida, T.; Kamioka, K.; Nishimura, T. [College of Engineering and Research Center of Ion Beam Technology, Hosei University, Koganei, Tokyo 184-8584 (Japan); Kuriyama, K., E-mail: kuri@ionbeam.hosei.ac.jp [College of Engineering and Research Center of Ion Beam Technology, Hosei University, Koganei, Tokyo 184-8584 (Japan); Kushida, K. [Department of Arts and Sciences, Osaka Kyoiku University, Kashiwara, Osaka 582-8582 (Japan); Kinomura, A. [National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan)

2015-12-15

The origins of low resistivity in H ion-implanted ZnO bulk single crystals are evaluated by elastic recoil detection analysis (ERDA), electron paramagnetic resonance (EPR), and Van der Pauw methods. The H-ion implantation (peak concentration: 5.0 × 10{sup 15} cm{sup −2}) into ZnO is performed using a 500 keV implanter. The maximum of the concentration of the implanted H estimated by a TRIM simulation is at 3600 nm in depth. The resistivity decreases from ∼10{sup 3} Ω cm for un implanted ZnO to 6.5 Ω cm for as-implanted, 2.3 × 10{sup −1} Ω cm for 200 °C annealed, and 3.2 × 10{sup −1} Ω cm for 400 °C annealed samples. The ERDA measurements can evaluate the concentration of hydrogens which move to the vicinity of the surface (surface to 300 nm or 100 nm) because of the diffusion by the annealing at 200 °C and 400 °C. The hydrogen concentration near the surface estimated using the 2.0 MeV helium beam is ∼3.8 × 10{sup 13} cm{sup −2} for annealed samples. From EPR measurements, the oxygen vacancy of +charge state (V{sub o}{sup +}) is observed in as-implanted samples. The V{sub o}{sup +} related signal (g = 1.96) observed under no illumination disappears after successive illumination with a red LED and appears again with a blue light illumination. The activation energy of as-implanted, 200 °C annealed, and 400 °C annealed samples estimated from the temperature dependence of carrier concentration lies between 29 meV and 23 meV, suggesting the existence of H interstitial as a shallow donor level.

Quantitative analysis of swelling on annealing of hydrogen ion implanted diamond single crystals

International Nuclear Information System (INIS)

Kuznetsov, G.F.

2006-01-01

Local swelling observed upon high-temperature annealing of natural diamond single crystals implanted by 350-keV hydrogen ions with a dose of 12 10 16 cm 2 is studied. Based on room-temperature measurements, Griffith cracking criterion in combination with gas law, model quantitative calculations of the swelling size and the amount of hydrogen molecules in a swelling have been carried out for the first time. At room temperature, T 1 293 K, the amount of local elastic stresses in the upper layer of the diamond is counterbalanced by inner hydrogen pressure. Behavior of the gas bubbles with the annealing temperature increase up to 1693 K and repeated annealing at a temperature of 1743 K has been calculated [ru

Attainability and minimum energy of single-stage membrane and membrane/distillation hybrid processes

KAUST Repository

Alshehri, Ali

2014-12-01

As an energy-efficient separation method, membrane technology has attracted more and more attentions in many challenging separation processes. The attainability and the energy consumption of a membrane process are the two basic fundamental questions that need to be answered. This report aims to use process simulations to find: (1) at what conditions a single-stage membrane process can meet the separation task that is defined by product purity and recovery ratio and (2) what are the most important parameters that determine the energy consumption. To perform a certain separation task, it was found that both membrane selectivity and pressure ratio exhibit a minimum value that is defined only by product purity and recovery ratio. The membrane/distillation hybrid system was used to study the energy consumption. A shortcut method was developed to calculate the minimum practical separation energy (MPSE) of the membrane process and the distillation process. It was found that the MPSE of the hybrid system is only determined by the membrane selectivity and the applied transmembrane pressure ratio in three stages. At the first stage when selectivity is low, the membrane process is not competitive to the distillation process. Adding a membrane unit to a distillation tower will not help in reducing energy. At the second medium selectivity stage, the membrane/distillation hybrid system can help reduce the energy consumption, and the higher the membrane selectivity, the lower is the energy. The energy conservation is further improved as pressure ratio increases. At the third stage when both selectivity and pressure ratio are high, the hybrid system will change to a single-stage membrane unit and this change will cause significant reduction in energy consumption. The energy at this stage keeps decreasing with selectivity at slow rate, but slightly increases with pressure ratio. Overall, the higher the membrane selectivity, the more the energy is saved. Therefore, the two

Self-supporting film method of silicon single crystal by ion implantation and it`s application

Energy Technology Data Exchange (ETDEWEB)

Saito, Kazuo; Nakao, Setsuo; Niwa, Hiroaki; Miyagawa, Soji [National Industrial Research Inst. of Nagoya (Japan)

1996-12-01

A few {mu}m of thickness of self-supporting film of silicon single crystal was produced by the ion implantation and the selective etching. This materials are distinguished by a uniform film thickness, good controllability, crystallization and the mechanical strength. For applying it to device, the detailed process has to be established, because there are some improved problems such as pinhole and morphology on the surface. This materials are very useful to the basic experiment of the base for epitaxial growth under irradiation of ion beams and the ion beam analysis in the atmosphere. (S.Y.)

Aesthetic Surgical Approach for Bone Dehiscence Treatment by Means of Single Implant and Interdental Tissue Regeneration: A Case Report with Five Years of Follow-Up

Directory of Open Access Journals (Sweden)

Giorgio Lombardo

2016-01-01

Full Text Available The replacement of single anterior teeth by means of endosseous implants implies the achievement of success in restoring both aesthetic and function. However, the presence of wide endoperiodontal lesions can lead to horizontal hard and soft tissues defects after tooth extraction, making it impossible to correctly place an implant in the compromised alveolar socket. Vertical augmentation procedures have been proposed to solve these clinical situations, but the amount of new regenerated bone is still not predictable. Furthermore, bone augmentation can be complicated by the presence of adjacent teeth, especially if they bring with them periodontal defects. Therefore, it is used to restore periodontal health of adjacent teeth before making any augmentation procedures and to wait a certain healing period before placing an implant in vertically augmented sites, otherwise risking to obtain a nonsatisfactory aesthetic result. All of these procedures, however, lead to an expansion of treatment time which should affect patient compliance. For this reason, this case report suggests a surgical technique to perform vertical bone augmentation at a single gap left by a central upper incisor while placing an implant and simultaneously to regenerate the periodontal attachment of an adjacent lateral incisor, without compromising the aesthetic result.

Fueling of magnetically confined plasmas by single- and two-stage repeating pneumatic pellet injectors

International Nuclear Information System (INIS)

Gouge, M.J.; Combs, S.K.; Foust, C.R.; Milora, S.L.

1990-01-01

Advanced plasma fueling systems for magnetic fusion confinement experiments are under development at Oak Ridge National Laboratory (ORNL). The general approach is that of producing and accelerating frozen hydrogenic pellets to speeds in the kilometer-per-second range using single shot and repetitive pneumatic (light-gas gun) pellet injectors. The millimeter-to-centimeter size pellets enter the plasma and continuously ablate because of the plasma electron heat flux, depositing fuel atoms along the pellet trajectory. This fueling method allows direct fueling in the interior of the hot plasma and is more efficient than the alternative method of injecting room temperature fuel gas at the wall of the plasma vacuum chamber. Single-stage pneumatic injectors based on the light-gas gun concept have provided hydrogenic fuel pellets in the speed range of 1--2 km/s in single-shot injector designs. Repetition rates up to 5 Hz have been demonstrated in repetitive injector designs. Future fusion reactor-scale devices may need higher pellet velocities because of the larger plasma size and higher plasma temperatures. Repetitive two-stage pneumatic injectors are under development at ORNL to provide long-pulse plasma fueling in the 3--5 km/s speed range. Recently, a repeating, two-stage light-gas gun achieved repetitive operation at 1 Hz with speeds in the range of 2--3 km/s

The use of first stage bone augmentation screws to stabilize the surgical template in the second stage.

NARCIS (Netherlands)

Verhamme, L.M.; Meijer, G.J.; Berge, S.J.; Maal, T.J.J.

2015-01-01

A new method is presented in which the osteosynthesis screws from a first stage bone augmentation of the maxilla are used to stabilize the surgical template during implant placement in the second stage. This method was evaluated in one patient and the results compared to those of previous studies.

The use of first stage bone augmentation screws to stabilize the surgical template in the second stage

NARCIS (Netherlands)

Verhamme, L. M.; Meijer, G. J.; Bergé, S. J.; Maal, T. J J

2015-01-01

A new method is presented in which the osteosynthesis screws from a first stage bone augmentation of the maxilla are used to stabilize the surgical template during implant placement in the second stage. This method was evaluated in one patient and the results compared to those of previous studies.

Effect of cyclic load on vertical misfit of prefabricated and cast implant single abutment

Directory of Open Access Journals (Sweden)

Rudys Rodolfo de Jesus Tavarez

2011-02-01

Full Text Available OBJECTIVES: The purpose of this in vitro study was to evaluate misfit alterations at the implant/abutment interface of external and internal connection implant systems when subjected to cyclic loading. MATERIAL AND METHODS: Standard metal crowns were fabricated for 5 groups (n=10 of implant/abutment assemblies: Group 1, external hexagon implant and UCLA cast-on premachined abutment; Group 2, internal hexagon implant and premachined abutment; Group 3, internal octagon implant and prefabricated abutment; Group 4, external hexagon implant and UCLA cast-on premachined abutment; and Group 5, external hexagon implant and Ceraone abutment. For groups 1, 2, 3 and 5, the crowns were cemented on the abutments and in group 4 crowns were screwed directly on the implant. The specimens were subjected to 500,000 cycles at 19.1 Hz of frequency and non-axial load of 133 N in a MTS 810 machine. The vertical misfit (μm at the implant/abutment interface was evaluated before (B and after (A application of the cyclic loading. Data were analyzed statistically by using two-away ANOVA and Tukey's post-hoc test (p<0.05. RESULTS: Before loading values showed no difference among groups 2 (4.33±3.13, 3 (4.79±3.43 and 5 (3.86±4.60; between groups 1 (12.88±6.43 and 4 (9.67±3.08, and among groups 2, 3 and 4. However, groups 1 and 4 were significantly different from groups 2, 3 and 5. After loading values of groups 1 (17.28±8.77 and 4 (17.78±10.99 were significantly different from those of groups 2 (4.83±4.50, 3 (8.07±4.31 and 5 (3.81±4.84. There was a significant increase in misfit values of groups 1, 3 and 4 after cyclic loading, but not for groups 2 and 5. CONCLUSIONS: The cyclic loading and type of implant/abutment connection may develop a role on the vertical misfit at the implant/abutment interface.

Analysis of the causes of dental implant fracture: A retrospective clinical study.

Science.gov (United States)

Stoichkov, Biser; Kirov, Dimitar

2018-01-01

Fracture of osseointegrated dental implants is the most severe mechanical complication. The aim of the present study was to analyze possible causative factors for implant body fracture. One hundred and one patients with 218 fitted implants and a follow-up period of 3 to 10 years were studied. Factors associated with biomechanical and physiologic overloading such as parafunctional activity (eg, bruxism), occlusion, and cantilevers, and factors related to the planning of the dental prosthesis, available bone volume, implant area, implant diameter, number of implants, and their inclination were tracked. The impact of their effect was analyzed using the Bonferroni-corrected post-hoc Mann-Whitney test for each group. The incidence of dental implant fracture was 2.3% in the investigated cases. Improper treatment planning, bruxism, and time of the complication setting in were the main factors leading to this complication. Typical size effect was established only for available bruxism, occlusal errors, and their activity duration. These complications were observed most often with single crown prostheses, and in combination with parafunctional activities such as bruxism and lack of implant-protected occlusion. Occlusal overload due to bruxism or inappropriate or inadequate occlusion as a single factor or a combination of these factors during the first years after the functional load can cause implant fracture. Fracture of the implant body more frequently occurred with single crowns than with other implant-supported fixed dental prostheses.

A 5- Year Comparison of Marginal Bone Level Following Immediate Loading of Single-Tooth Implants Placed in Healed Alveolar Ridges and Extraction Sockets in the Maxilla.

Directory of Open Access Journals (Sweden)

Antoine Nicolas Berberi

2014-01-01

Full Text Available AbstractPurpose: The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol.Materials and Methods: Thirty-six patients in need of a single tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden. Implants were placed in healed ridges (group I or immediately into extraction sockets (group II. Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36 and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implantResults: Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study and all remaining implants osseointegrated successfully after 5 years of functional loading. The mean change in marginal bone loss after implant placement was 0.267±0.161 for one year, and 0.265±0.171 for three years and 0.213±0.185 for five years in extraction sockets and was 0.266±0.176 for one year and 0.219±0.175 for three years and 0.194±0.172 for five years in healed ridges group. Significant reduction of marginal bone loss was more pronounced in implants inserted in healed ridges (P

Temperature-phased anaerobic digestion of food waste: A comparison with single-stage digestions based on performance and energy balance.

Science.gov (United States)

Xiao, Benyi; Qin, Yu; Zhang, Wenzhe; Wu, Jing; Qiang, Hong; Liu, Junxin; Li, Yu-You

2018-02-01

The temperature-phased anaerobic digestion (TPAD) of food waste was studied for the purpose of comparing with single-stage mesophilic and thermophilic anaerobic digestion. The biogas and methane yields in the TPAD during the steady period were 0.759 ± 0.115 L/g added VS and 0.454 ± 0.201 L/g added VS, which were lower than those in the two single-stage anaerobic digestion. The improper sludge retention time may be the reason for the lower biogas and methane production in TPAD. The removal of volatile solids in the TPAD was 78.55 ± 4.59% and the lowest among the three anaerobic digestion processes. The reaction ratios of the four anaerobic digestion steps in the TPAD were all lower than those in the two single-stage anaerobic digestion. The energy conversion efficiency of the degraded substrate in the TPAD was similar with those in single-stage mesophilic and thermophilic anaerobic digestion systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydrodeoxygenation of oils from cellulose in single and two-stage hydropyrolysis

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Rocha, J.D.; Snape, C.E. [Strathclyde Univ., Glasgow (United Kingdom); Luengo, C.A. [Universidade Estadual de Campinas, SP (Brazil). Dept. de Fisica Aplicada

1996-09-01

To investigate the removal of oxygen (hydrodeoxygenation) during the hydropyrolysis of cellulose, single and two-stage experiments on pure cellulose have been carried out using hydrogen pressures up to 10 MPa and temperatures over the range 300-520{sup o}C. Carbon, oxygen and aromaticity balances have been determined from the product yields and compositions. For the two-stage tests, the primary oils were passed through a bed of commercial Ni/Mo {gamma}-alumina-supported catalyst (Criterion 424, presulphided) at 400{sup o}C. Raising the hydrogen pressure from atmospheric to 10 MPa increased the carbon conversion by 10 mole % which was roughly equally divided between the oil and hydrocarbon gases. The oxygen content of the primary oil was reduced by over 10% to below 20% w/w. The addition of a dispersed iron sulphide catalyst further increased the oil yield at 10 MPa and reduces the oxygen content of the oil by a further 10%. The effect of hydrogen pressure on oil yields was most pronounced at low flow rates where it is beneficial in helping to overcome diffusional resistances. Unlike the dispersed iron sulphide in the first stage, the use of the Ni-Mo catalyst in the second stage reduced both the oxygen content and aromaticity of the oils. (Author)

Comparative Analysis of Direct Hospital Care Costs between Aseptic and Two-Stage Septic Knee Revision

Science.gov (United States)

Kasch, Richard; Merk, Sebastian; Assmann, Grit; Lahm, Andreas; Napp, Matthias; Merk, Harry; Flessa, Steffen

2017-01-01

Background The most common intermediate and long-term complications of total knee arthroplasty (TKA) include aseptic and septic failure of prosthetic joints. These complications cause suffering, and their management is expensive. In the future the number of revision TKA will increase, which involves a greater financial burden. Little concrete data about direct costs for aseptic and two-stage septic knee revisions with an in depth-analysis of septic explantation and implantation is available. Questions/Purposes A retrospective consecutive analysis of the major partial costs involved in revision TKA for aseptic and septic failure was undertaken to compare 1) demographic and clinical characteristics, and 2) variable direct costs (from a hospital department’s perspective) between patients who underwent single-stage aseptic and two-stage septic revision of TKA in a hospital providing maximum care. We separately analyze the explantation and implantation procedures in septic revision cases and identify the major cost drivers of knee revision operations. Methods A total of 106 consecutive patients (71 aseptic and 35 septic) was included. All direct costs of diagnosis, surgery, and treatment from the hospital department’s perspective were calculated as real purchase prices. Personnel involvement was calculated in units of minutes. Results Aseptic versus septic revisions differed significantly in terms of length of hospital stay (15.2 vs. 39.9 days), number of reported secondary diagnoses (6.3 vs. 9.8) and incision-suture time (108.3 min vs. 193.2 min). The management of septic revision TKA was significantly more expensive than that of aseptic failure ($12,223.79 vs. $6,749.43) (p costs of explantation stage ($4,540.46) were lower than aseptic revision TKA ($6,749.43) which were again lower than those of the septic implantation stage ($7,683.33). All mean costs of stays were not comparable as they differ significantly (p cost drivers were the cost of the implant and

Optical properties of Cu implanted ZnO

International Nuclear Information System (INIS)

Cetin, A.; Kibar, R.; Ayvacikli, M.; Can, N.; Buchal, Ch.; Townsend, P.D.; Stepanov, A.L.; Karali, T.; Selvi, S.

2006-01-01

Nanoparticles of Cu have been made in zinc oxide crystals by ion implantation. The Cu ions were implanted at 400 keV into the (0 0 0 1) face of a single crystal. After implantation and after post-irradiation annealing there are numerous changes in the luminescence responses which include a variety of green and yellow emission bands. Following annealing at temperatures up to 1000 o C a green luminescence near 525 nm was observed which has been associated with the isolated Cu ions. The changes between as implanted and annealed luminescence signals suggests that the implants generate clustering or nanoparticle formation of Cu but anneals dissociate them

All-Ceramic Single Crown Restauration of Zirconia Oral Implants and Its Influence on Fracture Resistance: An Investigation in the Artificial Mouth

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Ralf-Joachim Kohal

2015-04-01

Full Text Available The aim of the current investigation was to evaluate the fracture resistance of one-piece zirconia oral implants with and without all-ceramic incisor crowns after long-term thermomechanical cycling. A total of 48 implants were evaluated. The groups with crowns (C, 24 samples and without crowns (N, 24 samples were subdivided according to the loading protocol, resulting in three groups of 8 samples each: Group “0” was not exposed to cyclic loading, whereas groups “5” and “10” were loaded with 5 and 10 million chewing cycles, respectively. This resulted in 6 different groups: C0/N0, C5/N5 and C10/N10. Subsequently, all 48 implants were statically loaded to fracture and bending moments were calculated. All implants survived the artificial aging. For the static loading the following average bending moments were calculated: C0: 326 Ncm; C5: 339 Ncm; C10: 369 Ncm; N0: 339 Ncm; N5: 398 Ncm and N10: 355 Ncm. To a certain extent, thermomechanical cycling resulted in an increase of fracture resistance which did not prove to be statistically significant. Regarding its fracture resistance, the evaluated ceramic implant system made of Y-TZP seems to be able to resist physiological chewing forces long-term. Restauration with all-ceramic single crowns showed no negative influence on fracture resistance.

Do breast implants adversely affect prognosis among those subsequently diagnosed with breast cancer? Findings from an extended follow-up of a Canadian cohort.

Science.gov (United States)

Lavigne, Eric; Holowaty, Eric J; Pan, Sai Yi; Xie, Lin; Villeneuve, Paul J; Morrison, Howard; Brisson, Jacques

2012-10-01

Cosmetic breast implants may impair the ability to detect breast cancers. The aims of this study were to examine whether implants and implant characteristics are associated with more advanced breast tumors at diagnosis and poorer survival. Study population includes all invasive breast cancer cases diagnosed during follow-up of the large Canadian Breast Implant Cohort. A total of 409 women with cosmetic breast implants and 444 women with other cosmetic surgery were diagnosed with breast cancer. These women were compared for stage at diagnosis using multinomial logistic regression models. Cox proportional hazards regression models were used for breast cancer-specific mortality analyses. Comparisons were also conducted according to implant characteristics. Compared with women with other cosmetic surgery, those with cosmetic breast implants had at later stage breast cancer diagnosis (OR of having stage III/IV vs. stage I at diagnosis: 3.04, 95% confidence interval (CI): 1.81-5.10; P breast cancer-specific mortality rate for women with breast implants relative to surgical controls was observed (HR = 1.32, 95% CI: 0.94-1.83, P = 0.11). No statistically significant differences in stage and breast cancer mortality were observed according to implant characteristics. At diagnosis, breast cancers tended to be at more advanced stages among women with cosmetic breast implants. Breast cancer-specific survival was lower in these women although the reduction did not reach statistical significance. Further investigations of the effect of breast implants on breast cancer prognosis are warranted. 2012 AACR

Implant experience with an implantable hemodynamic monitor for the management of symptomatic heart failure.

Science.gov (United States)

Steinhaus, David; Reynolds, Dwight W; Gadler, Fredrik; Kay, G Neal; Hess, Mike F; Bennett, Tom

2005-08-01

Management of congestive heart failure is a serious public health problem. The use of implantable hemodynamic monitors (IHMs) may assist in this management by providing continuous ambulatory filling pressure status for optimal volume management. The Chronicle system includes an implanted monitor, a pressure sensor lead with passive fixation, an external pressure reference (EPR), and data retrieval and viewing components. The tip of the lead is placed near the right ventricular outflow tract to minimize risk of sensor tissue encapsulation. Implant technique and lead placement is similar to that of a permanent pacemaker. After the system had been successfully implanted in 148 patients, the type and frequency of implant-related adverse events were similar to a single-chamber pacemaker implant. R-wave amplitude was 15.2 +/- 6.7 mV and the pressure waveform signal was acceptable in all but two patients in whom presence of artifacts required lead repositioning. Implant procedure time was not influenced by experience, remaining constant throughout the study. Based on this evaluation, permanent placement of an IHM in symptomatic heart failure patients is technically feasible. Further investigation is warranted to evaluate the use of the continuous hemodynamic data in management of heart failure patients.

Genomic Prediction of Single Crosses in the Early Stages of a Maize Hybrid Breeding Pipeline

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Dnyaneshwar C. Kadam

2016-11-01

Full Text Available Prediction of single-cross performance has been a major goal of plant breeders since the beginning of hybrid breeding. Recently, genomic prediction has shown to be a promising approach, but only limited studies have examined the accuracy of predicting single-cross performance. Moreover, no studies have examined the potential of predicting single crosses among random inbreds derived from a series of biparental families, which resembles the structure of germplasm comprising the initial stages of a hybrid maize breeding pipeline. The main objectives of this study were to evaluate the potential of genomic prediction for identifying superior single crosses early in the hybrid breeding pipeline and optimize its application. To accomplish these objectives, we designed and analyzed a novel population of single crosses representing the Iowa Stiff Stalk synthetic/non-Stiff Stalk heterotic pattern commonly used in the development of North American commercial maize hybrids. The performance of single crosses was predicted using parental combining ability and covariance among single crosses. Prediction accuracies were estimated using cross-validation and ranged from 0.28 to 0.77 for grain yield, 0.53 to 0.91 for plant height, and 0.49 to 0.94 for staygreen, depending on the number of tested parents of the single cross and genomic prediction method used. The genomic estimated general and specific combining abilities showed an advantage over genomic covariances among single crosses when one or both parents of the single cross were untested. Overall, our results suggest that genomic prediction of single crosses in the early stages of a hybrid breeding pipeline holds great potential to redesign hybrid breeding and increase its efficiency.

Quantum effects in ion implanted devices

International Nuclear Information System (INIS)

Jamieson, D.N.; Chan, V.; Hudson, F.E.; Andresen, S.E.; Yang, C.; Hopf, T.; Hearne, S.M.; Pakes, C.I.; Prawer, S.; Gauja, E.; Yang, C.; Dzurak, A.S.; Yang, C.; Clark, R.G.; Yang, C.

2005-01-01

Fabrication of nanoscale devices that exploit the rules of quantum mechanics to process information presents formidable technical challenges because it will be necessary to control quantum states at the level of individual atoms, electrons or photons. We have developed a pathway to the construction of quantum devices using ion implantation and demonstrate, using charge transport analysis, that the devices exhibit single electron effects. We construct devices that employ two P donors in Si by employing the technique of ion beam induced charge (IBIC) in which single 14 keV P ions can be implanted into ultra-pure silicon by monitoring on-substrate detector electrodes. We have used IBIC with a MeV nuclear microprobe to map and measure the charge collection efficiency in the development of the electrode structure and show that 100% charge collection efficiency can be achieved leading to the fabrication of prototype devices that display quantum effects in the transport of single charge quanta between the islands of implanted donors. (author). 9 refs., 4 figs., 1 tab

Performance of the rebuilt SUERC single-stage accelerator mass spectrometer

Science.gov (United States)

Shanks, Richard P.; Ascough, Philippa L.; Dougans, Andrew; Gallacher, Paul; Gulliver, Pauline; Rood, Dylan H.; Xu, Sheng; Freeman, Stewart P. H. T.

2015-10-01

The SUERC bipolar single-stage accelerator mass spectrometer (SSAMS) has been dismantled and rebuilt to accommodate an additional rotatable pre-accelerator electrostatic spherical analyser (ESA) and a second ion source injector. This is for the attachment of an experimental positive-ion electron cyclotron resonance (ECR) ion source in addition to a Cs-sputter source. The ESA significantly suppresses oxygen interference to radiocarbon detection, and remaining measurement interference is now thought to be from 13C injected as 13CH molecule scattering off the plates of a second original pre-detector ESA.

Evaluation of the influence exerted by different dental specialty backgrounds and measuring instrument reproducibility on esthetic aspects of maxillary implant-supported single crown.

Science.gov (United States)

Vaidya, Samriddhi; Ho, Yu Lau Elaine; Hao, Jie; Lang, Niklaus P; Mattheos, Nikos

2015-03-01

To evaluate the influence exerted by different dental specialty backgrounds as well as the validity and reproducibility of the Pink Esthetic Score/White Esthetic Score (PES/WES) and the modified Implant Crown Aesthetic Index (mod-ICAI) on the assessment of esthetic aspects of maxillary implants supported single-tooth prosthesis. A total of fourteen examiners (Two orthodontists, two prosthodontists, two oral surgeons, two periodontists, two dental technicians, two dental assistants, and two postgraduate students in Implant Dentistry evaluated 20 photographs of single-implant-supported crowns and five photographs of unrestored teeth of esthetic zone in a two part study. The examiners assessed the photographs with each index (Pink Esthetic Score/White Esthetic Score and modified Implant Crown Aesthetic Index), twice with a week's interval. Orders of photographs were rearranged in the second assessment. Kruskal-Wallis test results showed significant differences among all the six specialties (P ≤ 0.001). DAs and periodontists had significantly better ratings than other specialties with both indices. Prosthodontists had the lowest mean rank scores regardless of the index. Interobserver agreement was also lowest between the two prosthodontists (4-28%), rest of the groups had low-to-moderate agreement (20-80%) when limited allowance was accepted. With mod-ICAI, more interobserver agreement was noted within the specialty group than with PES/WES. The PES/WES and the modified ICAI can be reliable estimates of esthetic outcomes. The assessor degree of specialization affected the esthetic evaluation with both the PES/WES and the modified ICAI. DAs and periodontists were identified to provide more favorable ratings than other specialties while prosthodontists were most critical in this study. With modified ICAI, more interobserver agreement within specialty resulted. The interexaminer agreement may be increased if more tolerance of 1-2 points is considered. © 2014 John Wiley

A two-phase inspection model for a single component system with three-stage degradation

International Nuclear Information System (INIS)

Wang, Huiying; Wang, Wenbin; Peng, Rui

2017-01-01

This paper presents a two-phase inspection schedule and an age-based replacement policy for a single plant item contingent on a three-stage degradation process. The two phase inspection schedule can be observed in practice. The three stages are defined as the normal working stage, low-grade defective stage and critical defective stage. When an inspection detects that an item is in the low-grade defective stage, we may delay the preventive replacement action if the time to the age-based replacement is less than or equal to a threshold level. However, if it is above this threshold level, the item will be replaced immediately. If the item is found in the critical defective stage, it is replaced immediately. A hybrid bee colony algorithm is developed to find the optimal solution for the proposed model which has multiple decision variables. A numerical example is conducted to show the efficiency of this algorithm, and simulations are conducted to verify the correctness of the model. - Highlights: • A two-phase inspection model is studied. • The failure process has three stages. • The delayed replacement is considered.

Colocación transpectoral superior de implantes mamarios: Relevancia técnica y anatómica Superior transpectoral insertion of breast implants: Anatomical and technical relevance

Directory of Open Access Journals (Sweden)

G. Peña Cabús

2008-12-01

dissection. A small but representative serie of cases, due to a unique single outcome, which was the main objective of the study, forced to an early stage investigational report. The clinical experience refers to a caudal subfascial plane and a subpectoral cephalic plane to create an implantation cavity in a 15 cases serie when every single case operated on did not showed any surface breast deformation upon pectoral muscle forced contraction. At this point earlier than anticipated, the study was thought to be sufficient and completed. Main interest is being attracted to the consequences of the particular tissue components involved in the formation of the wall capsule surrounding the breast implant. We do believe that the soft handling of breast implants and other implantable biomaterials, refers to maintenance of the implant material integrity and a non responsive tissue behavior, on the long term basis.

Plasma gasification of refuse derived fuel in a single-stage system using different gasifying agents.

Science.gov (United States)

Agon, N; Hrabovský, M; Chumak, O; Hlína, M; Kopecký, V; Masláni, A; Bosmans, A; Helsen, L; Skoblja, S; Van Oost, G; Vierendeels, J

2016-01-01

The renewable evolution in the energy industry and the depletion of natural resources are putting pressure on the waste industry to shift towards flexible treatment technologies with efficient materials and/or energy recovery. In this context, a thermochemical conversion method of recent interest is plasma gasification, which is capable of producing syngas from a wide variety of waste streams. The produced syngas can be valorized for both energetic (heat and/or electricity) and chemical (ammonia, hydrogen or liquid hydrocarbons) end-purposes. This paper evaluates the performance of experiments on a single-stage plasma gasification system for the treatment of refuse-derived fuel (RDF) from excavated waste. A comparative analysis of the syngas characteristics and process yields was done for seven cases with different types of gasifying agents (CO2+O2, H2O, CO2+H2O and O2+H2O). The syngas compositions were compared to the thermodynamic equilibrium compositions and the performance of the single-stage plasma gasification of RDF was compared to that of similar experiments with biomass and to the performance of a two-stage plasma gasification process with RDF. The temperature range of the experiment was from 1400 to 1600 K and for all cases, a medium calorific value syngas was produced with lower heating values up to 10.9 MJ/Nm(3), low levels of tar, high levels of CO and H2 and which composition was in good agreement to the equilibrium composition. The carbon conversion efficiency ranged from 80% to 100% and maximum cold gas efficiency and mechanical gasification efficiency of respectively 56% and 95%, were registered. Overall, the treatment of RDF proved to be less performant than that of biomass in the same system. Compared to a two-stage plasma gasification system, the produced syngas from the single-stage reactor showed more favourable characteristics, while the recovery of the solid residue as a vitrified slag is an advantage of the two-stage set-up. Copyright �

Characterization of diamond amorphized by ion implantation

International Nuclear Information System (INIS)

Allen, W.R.; Lee, E.H.

1992-01-01

Single crystal diamond has been implanted at 1 MeV with 2 x 10 20 Ar/m 2 . Rutherford backscattering spectrometry in a channeled geometry revealed a broad amorphized region underlying a thin, partially crystalline layer. Raman spectroscopy disclosed modifications in the bonding characteristic of the appearance of non-diamond carbon. The complementary nature of the two analysis techniques is demonstrated. The Knoop hardness of the implanted diamond was reduced by implantation

Effect of pre-implanted oxygen in Si on the retention of implanted He

Energy Technology Data Exchange (ETDEWEB)

Manuaba, A. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary); Paszti, F. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary)]. E-mail: paszti@rmki.kfki.hu; Ramos, A.R. [ITN - Instituto Tecnologico e Nuclear, Estrada Nacional 10, P-2686-953, Sacavem (Portugal); Khanh, N.Q. [MTA Research Institute for Technical Physics and Materials Science, P.O. Box 49, H-1525 Budapest (Hungary); Pecz, B. [MTA Research Institute for Technical Physics and Materials Science, P.O. Box 49, H-1525 Budapest (Hungary); Zolnai, Z. [MTA Research Institute for Technical Physics and Materials Science, P.O. Box 49, H-1525 Budapest (Hungary); Tunyogi, A. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary); Szilagyi, E. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary)

2006-08-15

Buried SiO {sub x} layers, with different x values, were formed by implanting 80 keV O{sup +} ions with different fluences into single crystal Si samples at room temperature. Into each of these O pre-implanted layers, 20 keV He{sup +} was implanted up to the fluence of 1 x 10{sup 17} ion/cm{sup 2}. The He distribution profiles were determined by 2045 keV proton backscattering spectrometry. It was found that as the O content increases, the retained He gradually decreases at the beginning, then rapidly falls at x = 0.6 till it disappears at x = 1.3. The process that leads to this phenomenon is discussed.

Modeling of X-ray rocking curves for layers after two-stage ion-implantation

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O.I. Liubchenko

2017-10-01

Full Text Available In this work, we consider the approach for simulation of X-ray rocking curves inherent to InSb(111 crystals implanted with Be+ ions with various energies and doses. The method is based on the semi-kinematical theory of X-ray diffraction in the case of Bragg geometry. A fitting procedure that relies on the Hooke–Jeeves direct search algorithm was developed to determine the depth profiles of strain and structural disorders in the ion-modified layers. The thickness and maximum value of strain of ion-modified InSb(111 layers were determined. For implantation energies 66 and 80 keV, doses 25 and 50 µC, the thickness of the strained layer is about 500 nm with the maximum value of strain close to 0.1%. Additionally, an amorphous layer with significant thickness was found in the implantation region.

Amorphization of tantalum by boron and phosphorus ion implantation

International Nuclear Information System (INIS)

Thome, L.; Benyagoub, A.; Bernas, H.; Pivin, J.C.; Cahn, R.W.

1984-01-01

The nature and depth dependence of the disorder produced by B and P implantation in Ta single crystals were studied in situ via channeling experiments and after implantation via grazing incidence electron diffraction experiments. The correlation of experimental results with implanted impurity profiles determined by SIMS shows that amorphous Ta-B and Ta-P alloys are produced for, respectively, 19% and 8% B and P concentrations in the implanted layer [fr

Investigation of Advanced Propellants to Enable Single Stage to Orbit Launch Vehicles

Science.gov (United States)

2006-10-30

ERS-PAS-2006-205) 13. SUPPLEMENTARY NOTES Graduate work for California State University, Fresno 14. ABSTRACT Single-Stage-To-Orbit ( SSTO ...and maintained. Despite well-funded development efforts, no SSTO vehicles have been fielded to date. Existing chemical rocket and vehicle...technologies do not enable feasible SSTO designs. In the future, new propellants with advanced properties could enable SSTO launch vehicles. A parametric

Localizing ECoG electrodes on the cortical anatomy without post-implantation imaging

Science.gov (United States)

Gupta, Disha; Hill, N. Jeremy; Adamo, Matthew A.; Ritaccio, Anthony; Schalk, Gerwin

2014-01-01

Introduction Electrocorticographic (ECoG) grids are placed subdurally on the cortex in people undergoing cortical resection to delineate eloquent cortex. ECoG signals have high spatial and temporal resolution and thus can be valuable for neuroscientific research. The value of these data is highest when they can be related to the cortical anatomy. Existing methods that establish this relationship rely either on post-implantation imaging using computed tomography (CT), magnetic resonance imaging (MRI) or X-Rays, or on intra-operative photographs. For research purposes, it is desirable to localize ECoG electrodes on the brain anatomy even when post-operative imaging is not available or when intra-operative photographs do not readily identify anatomical landmarks. Methods We developed a method to co-register ECoG electrodes to the underlying cortical anatomy using only a pre-operative MRI, a clinical neuronavigation device (such as BrainLab VectorVision), and fiducial markers. To validate our technique, we compared our results to data collected from six subjects who also had post-grid implantation imaging available. We compared the electrode coordinates obtained by our fiducial-based method to those obtained using existing methods, which are based on co-registering pre- and post-grid implantation images. Results Our fiducial-based method agreed with the MRI–CT method to within an average of 8.24 mm (mean, median = 7.10 mm) across 6 subjects in 3 dimensions. It showed an average discrepancy of 2.7 mm when compared to the results of the intra-operative photograph method in a 2D coordinate system. As this method does not require post-operative imaging such as CTs, our technique should prove useful for research in intra-operative single-stage surgery scenarios. To demonstrate the use of our method, we applied our method during real-time mapping of eloquent cortex during a single-stage surgery. The results demonstrated that our method can be applied intra

A 5-year comparison of marginal bone level following immediate loading of single-tooth implants placed in healed alveolar ridges and extraction sockets in the maxilla.

Science.gov (United States)

Berberi, Antoine N; Sabbagh, Joseph M; Aboushelib, Moustafa N; Noujeim, Ziad F; Salameh, Ziad A

2014-01-01

The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol. Thirty-six patients in need of a single-tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden). Implants were placed either in healed ridges (group I) or immediately into fresh extraction sockets (group II). Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36, and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implant. Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study. The mean change in marginal bone loss (MBL) after implant placement was 0.26 ± 0.161 mm for 1 year, and 0.26 ± 0.171 mm for 3 years, and 0.21 ± 0.185 mm for 5 years in extraction sockets and was 0.26 ± 0.176 mm for 1 year and 0.21 ± 0.175 mm for 3 years, and 0.19 ± 0.172 mm for 5 years in healed ridges group. Significant reduction of marginal bone was more pronounced in implants inserted in healed ridges (P sockets (P sockets or healed ridges were similar. Functional loading technique by using prefabricated abutment placed during the surgery time seems to maintain marginal bone around implant in both healed and fresh extraction sites.

A 5-year comparison of marginal bone level following immediate loading of single-tooth implants placed in healed alveolar ridges and extraction sockets in the maxilla

Science.gov (United States)

Berberi, Antoine N.; Sabbagh, Joseph M.; Aboushelib, Moustafa N.; Noujeim, Ziad F.; Salameh, Ziad A.

2014-01-01

Purpose: The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol. Materials and Methods: Thirty-six patients in need of a single-tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden). Implants were placed either in healed ridges (group I) or immediately into fresh extraction sockets (group II). Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36, and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implant. Results: Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study. The mean change in marginal bone loss (MBL) after implant placement was 0.26 ± 0.161 mm for 1 year, and 0.26 ± 0.171 mm for 3 years, and 0.21 ± 0.185 mm for 5 years in extraction sockets and was 0.26 ± 0.176 mm for 1 year and 0.21 ± 0.175 mm for 3 years, and 0.19 ± 0.172 mm for 5 years in healed ridges group. Significant reduction of marginal bone was more pronounced in implants inserted in healed ridges (P prefabricated abutment placed during the surgery time seems to maintain marginal bone around implant in both healed and fresh extraction sites. PMID:24550840

Single-stage soft tissue reconstruction and orbital fracture repair for complex facial injuries.

Science.gov (United States)

Wu, Peng Sen; Matoo, Reshvin; Sun, Hong; Song, Li Yuan; Kikkawa, Don O; Lu, Wei

2017-02-01

Orbital fractures with open periorbital wounds cause significant morbidity. Timing of debridement with fracture repair and soft tissue reconstruction is controversial. This study focuses on the efficacy of early single-stage repair in combined bony and soft tissue injuries. Retrospective review. Twenty-three patients with combined open soft tissue wounds and orbital fractures were studied for single-stage orbital reconstruction and periorbital soft tissue repair. Inclusion criteria were open soft tissue wounds with clinical and radiographic evidence of orbital fractures and repair performed within 48 h after injury. Surgical complications and reconstructive outcomes were assessed over 6 months. The main outcome measures were enophthalmos, pre- and post-CT imaging of orbits, scar evaluation, presence of diplopia, and eyelid position. Enophthalmos was corrected in 16/19 cases and improved in 3/19 cases. 3D reconstruction of CT images showed markedly improved orbital alignment with objective measurements of the optic foramen to cornea distance (mm) in reconstructed orbits relative to intact orbits of 0.66, 95% confidence interval [CI] (lower 0.33, upper 0.99) mm. The mean baseline of Stony Brook Scar Evaluation Scale was 0.6, 95%CI (0.30-0.92), and for 6 months, the mean score was 3.4, 95%CI (3.05-3.73). Residual diplopia in secondary gazes was present in two patients; one patient had ectropion. Complications included one case of local wound infection. An early single-stage repair of combined soft tissue and orbital fractures yields satisfactory functional and aesthetic outcomes. Complications are low and likely related to trauma severity. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Diagnostic Principles of Peri-Implantitis: a Systematic Review and Guidelines for Peri-Implantitis Diagnosis Proposal

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Ausra Ramanauskaite

2016-09-01

Full Text Available Objectives: To review and summarize the literature concerning peri-implantitis diagnostic parameters and to propose guidelines for peri-implantitis diagnosis. Material and Methods: An electronic literature search was conducted of the MEDLINE (Ovid and EMBASE databases for articles published between 2011 and 2016. Sequential screening at the title/abstract and full-text levels was performed. Systematic reviews/guidelines of consensus conferences proposing classification or suggesting diagnostic parameters for peri-implantitis in the English language were included. The review was recorded on PROSPERO system with the code CRD42016033287. Results: The search resulted in 10 articles that met the inclusion criteria. Four were papers from consensus conferences, two recommended diagnostic guidelines, three proposed classification of peri-implantitis, and one suggested an index for implant success. The following parameters were suggested to be used for peri-implantitis diagnosis: pain, mobility, bleeding on probing, probing depth, suppuration/exudate, and radiographic bone loss. In all of the papers, different definitions of peri-implantitis or implant success, as well as different thresholds for the above mentioned clinical and radiographical parameters, were used. Current evidence rationale for the diagnosis of peri-implantitis and classification based on consecutive evaluation of soft-tissue conditions and the amount of bone loss were suggested. Conclusions: Currently there is no single uniform definition of peri-implantitis or the parameters that should be used. Rationale for diagnosis and prognosis of peri-implantitis as well as classification of the disease is proposed.

Radiation-induced effects in MgO single crystal by 200 keV and 1 MeV Ni ion implantation

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Takahashi, Ryohei; Nakai, Yoshihiro; Hamaguchi, Dai [Kyoto Inst. of Tech. (Japan); and others

1997-03-01

MgO(100) single crystals were implanted with 1.0 MeV and 200 keV Ni ions between 10{sup 15} and 10{sup 17} ions/cm{sup 2} at room temperature. Before and after thermal annealing the radiation damage and the lattice location of implanted Ni ions were analyzed by using Rutherford backscattering spectrometry with channeling and optical absorption measurements. For 1.0 MeV Ni ions, the disorder of Mg atoms increased slowly with ion dose near surface region, while it increased sharply and saturated with ion dose from 2x10{sup 16} ions/cm{sup 2} near ion range. The radiation damage was recovered and implanted Ni ions diffused to the whole of crystal and occupied substitutional positions after 1400degC annealing. For 200 keV Ni ions, the disorder of Mg atoms increased with dose near ion range and had a maximum at about 5x10{sup 16} ions/cm{sup 2}. This tendency agrees with the behavior of color centers obtained from optical measurements. For thermal annealing the radiation damage did not change during 500degC annealing, but the aggregate centers appeared after 300degC annealing. (author)