[Acrylic resin removable partial dentures].

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de Baat, C; Witter, D J; Creugers, N H J

2011-01-01

An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of removable partial dentures, the acrylic resin removable partial denture has 3 favourable aspects: the economic aspect, its aesthetic quality and the ease with which it can be extended and adjusted. Disadvantages are an increased risk of caries developing, gingivitis, periodontal disease, denture stomatitis, alveolar bone reduction, tooth migration, triggering of the gag reflex and damage to the acrylic resin base. Present-day indications are ofa temporary or palliative nature or are motivated by economic factors. Special varieties of the acrylic resin removable partial denture are the spoon denture, the flexible denture fabricated of non-rigid acrylic resin, and the two-piece sectional denture. Furthermore, acrylic resin removable partial dentures can be supplied with clasps or reinforced by fibers or metal wires.

Effects of denture maintenance on satisfaction levels of Taiwanese elderly using removable partial dentures: a pilot study.

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Wu, Ju-Hui; Yang, Yi-Hsin; Wang, Chau-Hsiang; Lee, Huey-Er; Du, Je-Kang

2012-06-01

The aim of this study was to evaluate the correlation between patient satisfaction with removable partial dentures and denture maintenance by patients, including regular application of denture adhesives and cleansers. The success of removable partial dentures depends on patient satisfaction with dentures and their regular denture maintenance. Demographic information, the Oral Impacts on Daily Performance (OIDP) indicator and details of denture maintenance (including the use of denture cleansers and adhesives) were collected from 193 (41.5% men and 58.5% women) participants by using questionnaires. A dentist performed oral examinations to evaluate denture function according to the OIDP items photographically and recorded the number of remaining teeth and Kennedy's classification. Most participants were satisfied with their removable partial dentures and tended to have higher satisfaction levels than the dentist's estimation. Further, those using denture adhesives and cleansers had higher satisfaction levels than those not using such denture maintenance. Appropriate education regarding denture use is important because regular denture maintenance by patients affects their degree of satisfaction with dentures, as well as the dentist's skill and the patient's oral condition. Dentists could use this information to predict the potential success of dentures. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

Denture plaque--past and recent concerns.

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Nikawa, H; Hamada, T; Yamamoto, T

1998-05-01

This paper critically reviews the history of denture plaque and identifies some concerns with the presence of Candida in the mouth. This review covers literature sources related to Candida albicans and its relationship to denture plaque. The articles selected for this review are from referred journals and describe C. albicans and its relationship to oral, gastrointestinal and pleuropulmonary infections. The relationship to caries, root caries and periodontal disease is also covered. Denture plaque containing Candida could cause not only oral candidiasis, like oral thrush or denture-induced stomatitis, but also caries, root caries and periodontitis of abutment teeth. However, there is only limited experimental evidence or information available on the cariogenicity of Candida. The continuous swallowing or aspiration of micro-organisms from denture plaque exposes patients, particularly the immunocompromised host or medicated elderly, to the risks of unexpected infections. The term, 'denture plaque' has been used throughout the review. However, the term 'plaque on denture' should be used because the microbial flora and its pathogenicity of denture plaque resembles those of plaque formed on the tooth surface, so called dental plaque. In addition, the term 'denture related stomatitis' would be preferable to 'denture induced stomatitis', since the inflammation of (palatal) mucosa is not induced by the denture, but by wearing the denture or by plaque on the denture.

Improvdent: Improving dentures for patient benefit. A crossover randomised clinical trial comparing impression materials for complete dentures

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Gray Janine C

2012-08-01

Full Text Available Abstract Background According to the UK Adult Dental Health Survey (2009 15% of adults aged 65–74, 30% aged 75–84 and 47% aged >85 years are edentulous and require complete dentures. Patients’ quality of life and nutrition status are affected by poor dentures. The quality of the dental impression is the most important issue for improving the fit and comfort of new dentures. There is paucity of RCT evidence for which impression material is best for complete dentures construction. This study aims to compare two impression materials for effectiveness and cost effectiveness. Methods/Design IMPROVDENT is a double-blind crossover trial comparing the use of alginate and silicone, two commonly used denture impression materials, in terms of patient preference and cost-effectiveness. Eighty five edentulous patients will be recruited and provided with two sets of dentures, similar in all aspects except for the impression material used (alginate or silicone. Patients will try both sets of dentures for a two-week period, unadjusted, to become accustomed to the feel of the new dentures (habituation period. Patients will then wear each set of dentures for a period of 8 weeks (in random order during which time the dentures will be adjusted for optimum comfort. Finally, patients will be given both sets of dentures for a further two weeks to wear whichever denture they prefer (confirmation period. Patients will be asked about quality of life and to rate dentures on function and comfort at the end of each trial period and asked which set they prefer at the end of the habituation period (unadjusted denture preference and confirmation period (adjusted denture preference. A health economic evaluation will estimate incremental cost-effectiveness ratios of producing dentures from the two materials. A qualitative study will investigate the impact of dentures on behaviour and quality of life. Funding: IMPROVDENT is funded by NIHR RfPB (PB-PG-0408-16300. Discussion

CAD/CAM produces dentures with improved fit.

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Steinmassl, Otto; Dumfahrt, Herbert; Grunert, Ingrid; Steinmassl, Patricia-Anca

2018-02-22

Resin polymerisation shrinkage reduces the congruence of the denture base with denture-bearing tissues and thereby decreases the retention of conventionally fabricated dentures. CAD/CAM denture manufacturing is a subtractive process, and polymerisation shrinkage is not an issue anymore. Therefore, CAD/CAM dentures are assumed to show a higher denture base congruence than conventionally fabricated dentures. It has been the aim of this study to test this hypothesis. CAD/CAM dentures provided by four different manufacturers (AvaDent, Merz Dental, Whole You, Wieland/Ivoclar) were generated from ten different master casts. Ten conventional dentures (pack and press, long-term heat polymerisation) made from the same master casts served as control group. The master casts and all denture bases were scanned and matched digitally. The absolute incongruences were measured using a 2-mm mesh. Conventionally fabricated dentures showed a mean deviation of 0.105 mm, SD = 0.019 from the master cast. All CAD/CAM dentures showed lower mean incongruences. From all CAD/CAM dentures, AvaDent Digital Dentures showed the highest congruence with the master cast surface with a mean deviation of 0.058 mm, SD = 0.005. Wieland Digital Dentures showed a mean deviation of 0.068 mm, SD = 0.005, Whole You Nexteeth prostheses showed a mean deviation of 0.074 mm, SD = 0.011 and Baltic Denture System prostheses showed a mean deviation of 0.086 mm, SD = 0.012. CAD/CAM produces dentures with better fit than conventional dentures. The present study explains the clinically observed enhanced retention and lower traumatic ulcer-frequency in CAD/CAM dentures.

[Removable partial dentures. Oral functions and types].

Science.gov (United States)

Creugers, N H J; de Baat, C

2009-11-01

A removable partial denture enables the restoration or improvement of 4 oral functions: aesthetics, mandibular stability, mastication, and speech. However, wearing a removable partial denture should not cause oral comfort to deteriorate. There are 3 types of removable partial dentures: acrylic tissue-supported dentures, dentures with cast metal frameworks en dentures with cast metal frameworks and (semi)precision attachments. Interrupted tooth arches,free-ending tooth arches, and a combination of interrupted as well as free-ending tooth arches can be restored using these dentures. Well-known disadvantages of removable partial dentures are problematic oral hygiene, negative influence on the remaining dentition and limited oral comfort. Due to the advanced possibilities of fixed tooth- or implant-supported partial dentures, whether or not free-ending, or tooth- as well as implant-supported partial dentures, the indication of removable partial dentures is restricted. Nevertheless, for the time being the demand for removable partial dentures is expected to continue.

Swallowed dentures: Two cases and a review

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Mahir Gachabayov

2015-12-01

Conclusion: Fixed dentures can be accidentally ingested as well as removable dentures. Denture loosening leads to accidental denture ingestion. Patients with denture loosening should be recommended to visit dentist as soon as possible.

Overlay improvement methods with diffraction based overlay and integrated metrology

Science.gov (United States)

Nam, Young-Sun; Kim, Sunny; Shin, Ju Hee; Choi, Young Sin; Yun, Sang Ho; Kim, Young Hoon; Shin, Si Woo; Kong, Jeong Heung; Kang, Young Seog; Ha, Hun Hwan

2015-03-01

To accord with new requirement of securing more overlay margin, not only the optical overlay measurement is faced with the technical limitations to represent cell pattern's behavior, but also the larger measurement samples are inevitable for minimizing statistical errors and better estimation of circumstance in a lot. From these reasons, diffraction based overlay (DBO) and integrated metrology (IM) were mainly proposed as new approaches for overlay enhancement in this paper.

Cast Partial Denture versus Acrylic Partial Denture for Replacement of Missing Teeth in Partially Edentulous Patients

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Pramita Suwal

2017-03-01

Full Text Available Aim: To compare the effects of cast partial denture with conventional all acrylic denture in respect to retention, stability, masticatory efficiency, comfort and periodontal health of abutments. Methods: 50 adult partially edentulous patient seeking for replacement of missing teeth having Kennedy class I and II arches with or without modification areas were selected for the study. Group-A was treated with cast partial denture and Group-B with acrylic partial denture. Data collected during follow-up visit of 3 months, 6 months, and 1 year by evaluating retention, stability, masticatory efficiency, comfort, periodontal health of abutment. Results: Chi-square test was applied to find out differences between the groups at 95% confidence interval where p = 0.05. One year comparison shows that cast partial denture maintained retention and stability better than acrylic partial denture (p< 0.05. The masticatory efficiency was significantly compromising from 3rd month to 1 year in all acrylic partial denture groups (p< 0.05. The comfort of patient with cast partial denture was maintained better during the observation period (p< 0.05. Periodontal health of abutment was gradually deteriorated in all acrylic denture group (p

A study to evaluate the location and frequency of denture-related ulcerations and postinsertion adjustments in complete denture patients

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Saurabh Jain

2017-01-01

Full Text Available Background and Aims: Removable complete denture is one of the most common treatment modalities for completely edentulous patients. After denture insertion, patient very often faces problems with the denture even after complete care is taken during fabrication procedure. Most common complaint is traumatic ulcers. The present study aimed to locate the most common areas of ulcerations due to complete dentures, how frequently they occur and how many times patient visits for adjustment after insertion of complete denture. Materials and Methods: Two hundred and twenty-one patients were selected and were delivered complete dentures. Dentures were fabricated for all the patients. Each step of denture fabrication was controlled and guided by a prosthodontist. After placement of dentures, patients were evaluated at every recall visit and their dentures were adjusted. All the details of each visit (area of ulceration and number of visits were recorded in a self-designed format. Descriptive statistical analysis was done using SPSS version 13 software. Chi-squared test was used to evaluate the correlation between mucosal injuries and postinsertion day and the relationship between lesions, patient age, and patient gender. Results: All the 221 patients required denture adjustment due to mucosal injuries. No significant difference was found between denture-related injuries between males and females. Injuries related to mandibular dentures were significantly higher than those related to maxillary dentures. In mandible, the most common area of mucosal injury is posterior one-third of alveololingual sulcus; while in maxilla, the most common area of mucosal injury is labial frenum. Conclusion: Postinsertion adjustments are an important aspect of rehabilitating patient with complete dentures. Most of the denture-related injuries were in limiting areas. Proper border molding techniques, accurate secondary impressions, and use of pressure indicating paste during

Efficacy of denture adhesives in maxillary dentures using gnathodynamometry: a comparative study.

Science.gov (United States)

Polyzois, Gregory; Lagouvardos, Panagiotis; Frangou, Maria; Stefaniotis, Theodoros

2011-07-01

The purpose of this study was to investigate the effect of four commercially available denture adhesives on the incisal and premolar dislodgement forces of maxillary complete dentures by using an electronic and disposable gnathodynamometer and compare the measured incisal forces for differences. This study was conducted with 12 complete maxillary denture wearers. Four commercially available denture adhesives Super Corega(®), Corega Ultra(®), Super Corega Powder(®) and Fittydent Cationic(®) were investigated. Testing protocol and sequence included baseline measurements without adhesives (control) for previous and new dentures and then replications of measurements with the four adhesives. Maximum dislodgement forces were recorded in two sites between central incisors and the left 2nd premolars by using an electronic and disposable gnathodynamometer. To estimate the effect of the different adhesives on the dislodgement forces, data were analyzed by a 2- and 3-way ANOVA, while for estimating the agreement of the two devices a Bland-Altman and Mountain plots were used. ANOVAs indicated significant differences between adhesives (p adhesives increase the denture dislodgement forces, but with differences among them. The two devices do not highly agree with each other, but each one alone is useful in estimating dislodgement forces in clinical practice and research.

[Removable partial dentures. Oral functions and types

OpenAIRE

Creugers, N.H.J.; Baat, C. de

2009-01-01

A removable partial denture enables the restoration or improvement of 4 oral functions: aesthetics, mandibular stability, mastication, and speech. However, wearing a removable partial denture should not cause oral comfort to deteriorate. There are 3 types of removable partial dentures: acrylic tissue-supported dentures, dentures with cast metal frameworks en dentures with cast metal frameworks and (semi)precision attachments. Interrupted tooth arches,free-ending tooth arches, and a combinatio...

The effect of individually-induced processes on image-based overlay and diffraction-based overlay

Science.gov (United States)

Oh, SeungHwa; Lee, Jeongjin; Lee, Seungyoon; Hwang, Chan; Choi, Gilheyun; Kang, Ho-Kyu; Jung, EunSeung

2014-04-01

In this paper, set of wafers with separated processes was prepared and overlay measurement result was compared in two methods; IBO and DBO. Based on the experimental result, theoretical approach of relationship between overlay mark deformation and overlay variation is presented. Moreover, overlay reading simulation was used in verification and prediction of overlay variation due to deformation of overlay mark caused by induced processes. Through this study, understanding of individual process effects on overlay measurement error is given. Additionally, guideline of selecting proper overlay measurement scheme for specific layer is presented.

Denture quality has a minimal effect on health-related quality of life in patients with removable dentures.

Science.gov (United States)

Inoue, M; John, M T; Tsukasaki, H; Furuyama, C; Baba, K

2011-11-01

The present study examined the association of denture quality and health-related quality of life (HRQoL) in patients with removable dentures. In a study of 171 consecutive patients with removable partial dentures or complete dentures (mean age: 68·0 ± 9·3 years) at a university-based prosthodontic clinic, dentists rated two aspects of denture quality (stability and aesthetics) using a 100-mm visual analog scale (VAS). HRQoL was evaluated using the mental and physical component summary (MCS and PCS) scores of the Medical Outcomes Study Short-Form 36-Item Health Survey (SF-36). Oral health-related quality of life (OHRQoL) was evaluated using the Oral Health Impact Profile-Japanese version (OHIP-J). The associations among denture quality, OHRQoL, and HRQoL were examined by linear regression models. Bivariable linear regression analyses revealed that denture stability was significantly associated with the SF-36 MCS [regression coefficient = 0·52 for a 10-unit increase in denture stability on a 0-100 VAS, 95% confidence interval (CI): 0·03-1·00, P = 0·04], but not with the PCS (0·11, 95% CI: -0·49 to 0·70). Denture aesthetics was not related to the PCS or the MCS (0·22, 95% CI: -0·44 to 0·88 or 0·07, 95%CI: -0·47 to 0·62). When OHIP-J was added to the regression model, this variable was substantially and significantly associated with the MCS and PCS summary scores; in addition, the regression coefficient for denture quality decreased in magnitude and was statistically nonsignificant in all analyses. The quality of removable dentures had a minimal effect on HRQoL in patients with removable dentures, and this association was mediated by OHRQoL. © 2011 Blackwell Publishing Ltd.

Management of bruxism-induced complications in removable partial denture wearers using specially designed dentures: a clinical report.

Science.gov (United States)

Baba, Kazuyoshi; Aridome, Kumiko; Pallegama, Ranjith Wasantha

2008-01-01

In patients with a limited number of remaining teeth, bruxism force can be destructive for both the remaining teeth and periodontal structures. This paper reports the successful management of four such patients with severe sleep bruxism, using conventional removable partial dentures and specially designed, splint-like removable partial dentures called a night denture. The night denture was fabricated in two different designs, which depended upon the pattern of the remaining tooth contacts. The patients were followed up for 2-6 years using a night denture in either of the two designs. Within the limitations of these four reports of clinical cases, the night denture appeared to be effective in managing the problems related to sleep bruxism.

Denture Adhesives in Prosthodontics: An Overview.

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Kumar, P Ranjith; Shajahan, P A; Mathew, Jyothis; Koruthu, Anil; Aravind, Prasad; Ahammed, M Fazeel

2015-01-01

The use of denture adhesives is common among denture wearers, and it is also prescribed by many dentists. Prescribing denture adhesives has been viewed by many prosthodontists as a means of compensating for any defects in the fabrication procedures. Denture adhesives add to the retention and thereby improve chewing ability, reduce any instability, provide comfort and eliminate the accumulation of food debris beneath the dentures. Consequently, they increase the patient's sense of security and satisfaction. However, obtaining the advice of the dental practitioner prior to the use of adhesives is a must.

Adherence of Candida to complete denture surfaces in vitro: A comparison of conventional and CAD/CAM complete dentures.

Science.gov (United States)

Al-Fouzan, Afnan F; Al-Mejrad, Lamya A; Albarrag, Ahmed M

2017-10-01

The goal of this study was to compare the adhesion of Candida albicans to the surfaces of CAD/CAM and conventionally fabricated complete denture bases. Twenty discs of acrylic resin poly (methyl methacrylate) were fabricated with CAD/CAM and conventional procedures (heat-polymerized acrylic resin). The specimens were divided into two groups: 10 discs were fabricated using the CAD/CAM procedure (Wieland Digital Denture Ivoclar Vivadent), and 10 discs were fabricated using a conventional flasking and pressure-pack technique. Candida colonization was performed on all the specimens using four Candida albicans isolates. The difference in Candida albicans adhesion on the discs was evaluated. The number of adherent yeast cells was calculated by the colony-forming units (CFU) and by Fluorescence microscopy. There was a significant difference in the adhesion of Candida albicans to the complete denture bases created with CAD/CAM and the adhesion to those created with the conventional procedure. The CAD/CAM denture bases exhibited less adhesion of Candida albicans than did the denture bases created with the conventional procedure ( P CAD/CAM procedure for fabricating complete dentures showed promising potential for reducing the adherence of Candida to the denture base surface. Clinical Implications. Complete dentures made with the CAD/CAM procedure might decrease the incidence of denture stomatitis compared with conventional dentures.

Attitudes and usage of denture adhesives by complete denture wearers: a survey in Greece and the Netherlands.

Science.gov (United States)

Polyzois, Gregory L; de Baat, Cees

2012-06-01

To explore whether there are differences in usage of and attitudes towards denture adhesives among patients in two countries. There are no multi-country surveys concerning usage of and attitudes towards denture adhesives from complete denture wearers. The survey took place in Greece and the Netherlands with a sample of 284 and 165 consecutive complete denture wearers, respectively, by using a 9-item prepared questionnaire. Statistical analysis relied on chi-square test at α = 0.05. In this survey, 26 and 20% of Greek and Dutch patients, respectively, had tried denture adhesive, but only 27% of them in Greece as well as in the Netherlands currently used it; 49% of the Greek and 45% of the Dutch participants rated the overall performance of adhesives as good. Between the two populations, no differences were identified in a majority of the research variables, except where 27% of Greeks answered that they did not know the existence of denture adhesives compared to none of the Dutch patients and when 90% of the Dutch contrary to 70% of Greeks reported that they did not need denture adhesives as they could manage their dentures well. The usage of and attitudes towards denture adhesives between the Greek and Dutch sample were similar with only two exceptions concerning the knowledge of existence and the need of using denture adhesives. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

Denture adhesives: a systematic review.

Science.gov (United States)

Papadiochou, Sofia; Emmanouil, Ioannis; Papadiochos, Ioannis

2015-05-01

Denture adhesives have been the objective of scientific research for over half a century. Although they are used by denture wearers worldwide, investigations of their effectiveness and biocompatibility have led to controversial conclusions. The purpose of this study was to review the literature data with regard to the effectiveness and biocompatibility of denture adhesives as well as the attitudes of both patients and dental professionals toward these materials. An electronic search of English peer-reviewed dental literature in the Medline database was conducted to evaluate the effectiveness and biocompatibility of denture adhesives. There was no limitation in publication year, so the search included all the available scientific evidence included in that particular database until March 2014. Specific inclusion criteria were used for the selection of the appropriate articles. A manual search of the citations of the obtained articles followed to extend the electronic search. A full text review was carried out for only 32 articles. Of the 32 articles, 21 examined the efficacy of denture adhesives in terms of retention and stability and masticatory performance, 6 evaluated the issue of the biocompatibility of denture adhesives, and 5 presented the attitudes of either professionals or patients toward these materials. The majority of clinical studies supported the fact that denture adhesives enhance the retention, stability, and masticatory performance of a removable prosthesis. In terms of biocompatibility, long-term in vivo studies to investigate potential harmful effects were lacking. Patients are satisfied with denture adhesives that meet their needs. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

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

Science.gov (United States)

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

2013-04-01

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

Diffraction based overlay and image based overlay on production flow for advanced technology node

Science.gov (United States)

Blancquaert, Yoann; Dezauzier, Christophe

2013-04-01

One of the main challenges for lithography step is the overlay control. For the advanced technology node like 28nm and 14nm, the overlay budget becomes very tight. Two overlay techniques compete in our advanced semiconductor manufacturing: the Diffraction based Overlay (DBO) with the YieldStar S200 (ASML) and the Image Based Overlay (IBO) with ARCHER (KLA). In this paper we will compare these two methods through 3 critical production layers: Poly Gate, Contact and first metal layer. We will show the overlay results of the 2 techniques, explore the accuracy and compare the total measurement uncertainty (TMU) for the standard overlay targets of both techniques. We will see also the response and impact for the Image Based Overlay and Diffraction Based Overlay techniques through a process change like an additional Hardmask TEOS layer on the front-end stack. The importance of the target design is approached; we will propose more adapted design for image based targets. Finally we will present embedded targets in the 14 FDSOI with first results.

Attitudes and usage of denture adhesives by complete denture wearers: a survey in Greece and the Netherlands.

NARCIS (Netherlands)

Polyzois, G.L.; Baat, C. de

2012-01-01

OBJECTIVE: To explore whether there are differences in usage of and attitudes towards denture adhesives among patients in two countries. BACKGROUND: There are no multi-country surveys concerning usage of and attitudes towards denture adhesives from complete denture wearers. MATERIALS AND METHODS:

Efficacy of Denture Cleansers in Reducing Microbial Counts from Removable Partial Dentures: A Short-Term Clinical Evaluation

OpenAIRE

Lucena-Ferreira,Silvia Carneiro de; Cavalcanti,Indira Moraes Gomes; Cury,Altair Antoninha Del Bel

2013-01-01

This clinical study investigated if daily immersion in denture cleansers reduces microbial counts on removable partial denture's (RPD) biofilm. Twenty-five RPD wearer volunteers were selected and instructed to complement the hygiene of their dentures by immersing them in an enzymatic peroxide-based denture cleanser (Polident® 3 minute) once a day for 3 min for a period of 15 days. The biofilm was collected from RPD surfaces with a swab immediately before (baseline) and after the experimental ...

[Conventional retaining of removable partial dentures

NARCIS (Netherlands)

Keltjens, H.M.A.M.; Witter, D.J.; Creugers, N.H.J.

2009-01-01

Mechanical and biological criteria have to be met in retaining the metal frame of a removable partial denture. Additionally, a removable partial denture is part of the occlusal interface by the clasps and the denture teeth. With respect to mechanical aspects, all rigid parts of the removable partial

Efficacy of commercial and household denture cleansers against Candida albicans adherent to acrylic denture base resin: An in vitro study

Directory of Open Access Journals (Sweden)

M Nanditha Kumar

2012-01-01

Conclusion: Within the limitations of this in vitro study, denture cleansers were found to be effective in reducing C albicans cells adhering to dentures. The commercial denture cleansers (Fittydent® and Clinsodent® were more effective than household denture cleansers (vinegar and diluted vinegar.

The effectiveness of chemical denture cleansers and ultrasonic device in biofilm removal from complete dentures

Directory of Open Access Journals (Sweden)

Patrícia Costa Cruz

2011-12-01

Full Text Available Adequate denture hygiene can prevent and treat infection in edentulous patients. They are usually elderly and have difficulty for brushing their teeth. OBJECTIVE: This study evaluated the efficacy of complete denture biofilm removal using chemical (alkaline peroxide-effervescent tablets, mechanical (ultrasonic and combined (association of the effervescent and ultrasonic methods. MATERIAL AND METHODS: Eighty complete denture wearers participated in the experiment for 21 days. They were distributed into 4 groups (n=20: (1 Brushing with water (Control; (2 Effervescent tablets (Corega Tabs; (3 Ultrasonic device (Ultrasonic Cleaner, model 2840 D; (4 Association of effervescent tablets and ultrasonic device. All groups brushed their dentures with a specific brush (Bitufo and water, 3 times a day, before applying their treatments. Denture biofilm was collected at baseline and after 21 days. To quantify the biofilm, the internal surfaces of the maxillary complete dentures were stained and photographed at 45º. The photographs were processed and the areas (total internal surface stained with biofilm quantified (Image Tool 2.02. The percentage of the biofilm was calculated by the ratio between the biofilm area multiplied by 100 and the total area of the internal surface of the maxillary complete denture. RESULTS: The Kruskal-Wallis test was used for comparison among groups followed by the Dunn multiple-comparison test. All tests were performed respecting a significance level of 0.05. Significant difference was found among the treatments (KW=21.18; P<0.001, the mean ranks for the treatments and results for Dunn multiple comparison test were: Control (60.9; Chemical (37.2; Mechanical (35.2 and Combined (29.1. CONCLUSION: The experimental methods were equally effective regarding the ability to remove biofilm and were superior to the control method (brushing with water. Immersion in alkaline peroxide and ultrasonic vibration can be used as auxiliary agents

VT Data - Overlay District 20170407, Burlington

Data.gov (United States)

Vermont Center for Geographic Information — The following Overlay District Data is included:Design Review OverlayInstitutional Core Campus OverlayRH Density Bonus OverlayNatural Resource Protection OverlayRL...

Denture hygiene knowledge and practice amongst patients in a ...

African Journals Online (AJOL)

Aim: To assess patients' knowledge on denture hygiene and the hygiene methods used for cleaning removable partial dentures. Methods: This was a ... Other information obtained were the duration of denture use, frequency of denture cleaning and type of material used for denture cleaning. Results: The age of the ...

[Removable partial dentures. Oral functions and types

NARCIS (Netherlands)

Creugers, N.H.J.; Baat, C. de

2009-01-01

A removable partial denture enables the restoration or improvement of 4 oral functions: aesthetics, mandibular stability, mastication, and speech. However, wearing a removable partial denture should not cause oral comfort to deteriorate. There are 3 types of removable partial dentures: acrylic

Photoelectron emission from thin overlayers

International Nuclear Information System (INIS)

Jablonski, A.

2012-01-01

Highlights: ► Weak influence of the support on photoemission from an overlayer. ► Accurate description of photoelectron intensity from overlayer by analytical theory. ► Method for overlayer thickness measurements based on analytical formalism. ► Influence of photoelectron elastic scattering on calculated thickness. -- Abstract: Photoelectron signal intensities calculated for a thin overlayer from theoretical models taking elastic photoelectron collisions into account are shown to be very weakly dependent on the substrate material. This result has been obtained for photoelectrons analyzed in XPS spectrometers equipped with typical X-ray sources, i.e. sources of Mg Kα and Al Kα radiation. Low sensitivity to the substrate material is due to the fact that trajectories of photoelectrons emitted in the overlayer and entering the substrate have a low probability to reach the analyzer without energy loss. On the other hand, the signal intensity of photoelectrons emitted in the overlayer is found to be distinctly affected by elastic photoelectron scattering. Consequently, a theoretical model that can accurately describe the photoelectron intensity from an overlayer deposited on any material (e.g. on a substrate of the same material as the overlayer) can be a useful basis for a universal and convenient method for determination of the overlayer thickness. It is shown that the formalism derived from the kinetic Boltzmann equation within the so-called transport approximation satisfies these requirements. This formalism is postulated for use in overlayer-thickness measurements to avoid time-consuming Monte Carlo simulations of photoelectron transport, and also to circumvent problems with determining the effective attenuation lengths for overlayer/substrate systems.

Clinical application of removable partial dentures using thermoplastic resin-part I: definition and indication of non-metal clasp dentures.

Science.gov (United States)

Fueki, Kenji; Ohkubo, Chikahiro; Yatabe, Masaru; Arakawa, Ichiro; Arita, Masahiro; Ino, Satoshi; Kanamori, Toshikazu; Kawai, Yasuhiko; Kawara, Misao; Komiyama, Osamu; Suzuki, Tetsuya; Nagata, Kazuhiro; Hosoki, Maki; Masumi, Shin-Ichi; Yamauchi, Mutsuo; Aita, Hideki; Ono, Takahiro; Kondo, Hisatomo; Tamaki, Katsushi; Matsuka, Yoshizo; Tsukasaki, Hiroaki; Fujisawa, Masanori; Baba, Kazuyoshi; Koyano, Kiyoshi; Yatani, Hirofumi

2014-01-01

This position paper proposes a definition and naming standard for removable partial dentures (RPDs) using thermoplastic resin, and presents a guideline for clinical application. A panel of 14 experts having broad experience with clinical application of RPDs using thermoplastic resin was selected from members of the Japan Prosthodontic Society. At a meeting of the panel, "non-metal clasp denture" was referred as the generic name of RPDs with retentive elements (resin clasps) made of thermoplastic resin. The panel classified non-metal clasp dentures into two types: one with a flexible structure that lacks a metal framework and the other having a rigid structure that includes a metal framework. According to current prosthetic principles, flexible non-metal clasp dentures are not recommended as definitive dentures, except for limited cases such as patients with a metal allergy. Rigid non-metal clasp dentures are recommended in cases where patients will not accept metal clasps for esthetic reasons. Non-metal clasp dentures should follow the same design principles as conventional RPDs using metal clasps. Copyright © 2013 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Dental health professional recommendation and consumer habits in denture cleansing.

Science.gov (United States)

Axe, Alyson S; Varghese, Roshan; Bosma, MaryLynn; Kitson, Nicola; Bradshaw, David J

2016-02-01

Regular cleaning of dentures is essential to the oral and general health of denture wearers. Only limited systematic data are available on the recommendations that dental health care professionals (DHCPs) make to patients for denture cleaning. Data on denture wearers' cleaning regimens are also lacking. The purpose of this study was to provide data on recommendations that DHCPs make to patients for denture cleaning and on the cleaning regimens of denture wearers. DHCPs (n=613), including dentists and hygienists, were surveyed in developed (Japan, USA, Italy) and developing (Brazil, India) countries. A questionnaire assessing a range of denture cleaning recommendations was used. The questions addressed products, frequency, how to use remedies, the suggested dilution and duration of cleansing treatment, the location of dentures while cleaning, and the reasoning behind the recommendation of particular products or modes of treatment. Denture cleansing methods and the routine of denture wearers in developed and developing countries were also surveyed with a questionnaire (n=2862) and a 1-week diary (n=1462). An average of more than 2 treatments was recommended by DHCPs. Specialist denture cleanser tablets, "regular" toothpaste, mouthwash, soap and water, denture paste, foam or liquid denture cleanser, and dishwashing detergents were most commonly recommended; other product recommendations included baking soda, vinegar, salt water, and bleach. More than 10% of DHCPs made no primary recommendation on cleaning. Denture tablets were more commonly recommended in developed countries, whereas toothpaste was the most common recommendation in developing countries. Denture wearers used products and methods similar to those recommended by DHCPs. Toothpaste, water, and mouthwash were used more frequently than denture tablets. More than 75% of denture wearers reported using denture cleanser tablets for more than 5 minutes, whereas soap and toothpaste were typically used for less

VT Data - Overlay District 20170802, Shelburne

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Vermont Center for Geographic Information — The following Overlay Districts are included in the data:Lakeshore Conservation OverlyNeighborhood OverlayVillage Design Review OverlayVillage Core OverlayWater...

Pseudomembranous candidiasis in patient wearing full denture

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Nurdiana Nurdiana

2009-06-01

Full Text Available Background: Oral candidiasis is a common opportunistic infection of the oral cavity caused by an overgrowth of Candida species, the commonest being Candida albicans. Candida albicans is a harmless commensal organism inhabiting the mouths but it can change into pathogen and invade tissue and cause acute and chronic disease. Dentures predispose to infection with Candida in as many as 65% of elderly people wearing full upper dentures. Purpose: The purpose of this case report is to discuss thrush in patient wearing full denture which rapidly developed. Case: This paper report a case of 57 year-old man who came to the Oral Medicine Clinic Faculty of Dentistry Airlangga University with clinical appearance of pseudomembranous candidiasis (thrush. Case Management: Diagnosis of this case is confirmed with microbiology examination. Patient was wearing full upper dentures, and from anamnesis known that patient wearing denture for 24 hours and he had poor oral hygiene. Patient was treated with topical (nystatin oral suspension and miconazole oral gel and systemic (ketoconazole antifungal. Patient also instructed not to wear his denture and cleaned white pseudomembrane on his mouth with soft toothbrush. Conclusion: Denture, habit of wearing denture for 24 hours, and poor oral hygiene are predisposing factors of thrush and it can healed completely after treated with topical and systemic antifungal.

VT Data - Overlay District 20170228, Richmond

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Vermont Center for Geographic Information — The following overlay districts are included in the data:Shoreline Protection OverlayFlood Hazard OverlayDetails about these overlay districts, as well as zoning...

The Effect of Two Types of Denture Adhesive on the Satisfaction Parameters of Complete Denture Wearers

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Farzin M

2017-09-01

Full Text Available Statement of Problem: Patient satisfaction is highly influenced by the retention of the denture. In some instances using denture adhesives may help the patient to achieve this goal. Objectives: The purpose of this study was to evaluate the participants’ ’opinion concerning the effectiveness of two types of denture adhesives having the same composition (Fixative-powder, Protefix-cream. Materials and Methods: Forty healthy patients (25 Males and 15 Fe-males who visited the Department of Prosthodontics of Shiraz Dentistry School were selected. The oral cavity was examined and patients with oral ulcers, history of allergic reaction, severe xerostomia, red, white and/or red and white lesions were excluded. The subjects were instructed to receive a sequence of treatment protocols. All patients applied Fixative-powder on the dentures for seven days. The Participants were asked to fill a question-naire to include their opinion regarding the strength, biocompatibility, convenience and masticatory ability of the adhesive. On the next seven days, the patients were asked not to use the adhesives and they completed the same questionnaire again. Finally, all participants were asked to apply Protefix-cream on their dentures for a week followed by no cream applica-tion for another 7 days. These patients answered the same questionnaire and data were collected and analyzed using paired-samples t-test and Chi-square test. Result: Denture adhesives significantly improved the overall satisfaction level of the patients (p =0.01. When testing the fixative powder, the satis-faction score of the participants during the first week (powder application and the 2nd weak (no application was 19.95±3.76 and 26.2±2.82, respec-tively. The overall satisfaction rate of the patients using the Protefix adhe-sive was 19.35±5.48 in the third week (adhesive application and 25.85± 4.35 in the fourth week (no application. Conclusions: The study clarified that applying denture

Removable denture-related oral mucosal lesions: descriptive clinical study

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Gökçen Akçiçek

2017-05-01

Full Text Available Objective: The aim of this study was to investigate whether there was a relationship between removable denture-related oral mucosal lesions and denture type, and demographic characteristics. Materials and Method: The age, sex, denture type, systemic condition and medication use, presence of denture-related oral mucosal lesions (DROML, their locations and patients’ awareness of above mentioned lesions were recorded for 199 patients. Pearson chi-square test was used to analyse the relationship between the DROML and denture type, and demographic characteristics of the patients. Results: Among the patients included to the study, 122 (61.3% were female and 77 (38.7% were male. Ninety-six patients (48.2% exhibited DROML, whereas 103 patients (51.8% had no DROML. No relationship was detected between DROML and age, and sex (p>0.05. The most commonly detected DROML was denture stomatitis (34.7%. Denture stomatitis was significantly more frequently seen in partial denture wearers (p<0.05, while epulis fissuratum and flabby ridge were statistically more frequent in complete denture wearers (p<0.001. Traumatic ulcer was more frequently found in mandibular complete denture wearers (p<0.05, while epulis fissuratum and flabby ridge were significantly more common in maxillary complete denture wearers (p<0.001. Among the patients with DROML, 57.3% stated that they were unaware of these lesions. Conclusion: In this study sample, the rate of DROML was high in patients wearing removable dentures (48.2%, and more than half of the patients with DROML were not aware of these lesions. Upon these findings, it is considered that removable denture wearers should follow the denture usage instructions and should be informed about the importance of periodic controls.

Complication rates and patient satisfaction with removable dentures

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Bilhan, Hakan; Erdogan, Ozge; Ergin, Selen; Celik, Melahat; Ates, Gokcen

2012-01-01

PURPOSE The purpose of this clinical study was to evaluate the frequency and type of prosthetic complications in relation to type and properties of removable dentures and to investigate the influence of these complications and several data about the existing dentures on patient satisfaction. MATERIALS AND METHODS Ninety nine patients (44 males and 55 females) wearing removable dentures have been included in the study. The complications of the patients were recorded; patient satisfaction was determined with a Visual Analog Scale (VAS) and the relationship of complications and patient satisfaction with several data about the dentures such as denture age, type of denture, centric relation and vertical dimension was investigated. Kruskal Wallis, Mann Whitney U and Chi square tests were used for statistical analyses. The results were evaluated statistically at a significance level of Pdentures with correct centric relations was found to be significantly lower than dentures with wrong centric relations (Pdentures with wrong centric relations caused need for addition of artificial teeth. PMID:22737317

A follow-up study on removable partial dentures in undergraduate program: part I. participants and denture use by telephone survey.

Science.gov (United States)

Yoshida, Eiko; Fueki, Kenji; Igarashi, Yoshimasa

2011-07-04

The aim of this study was to investigate the clinical outcome of removable partial dentures (RPDs) designed to minimize denture mobility during function. Using archived files of the undergraduate program between 2003 and 2005 at Tokyo Medical and Dental University, a list of 169 patients treated with 184 RPDs was created. The RPDs had either an acrylic resin-base or a cobalt-chrome framework-base. Two examiners telephoned all the listed patients and interviewed 118 patients (70%) regarding the use of their RPDs. Of 118 patients, 42 (36%) had stopped using, mainly due to problems with abutment teeth in resin-based dentures, and replacement in cobalt-chrome-based dentures. There was no significant difference in mean age, gender distribution, mean number of remaining/abutment teeth, distribution of denture arch, and Kennedy classification between denture use and nonuse groups (p>0.05). The nonuse group showed a significantly higher percentage of resin-base compared to the use group (p = 0.006). Logistic regression analysis indicated that resin-base was a significant risk factor for nonuse (p = 0.008). The present findings suggest that abutment teeth should be selected carefully, especially in this type of resin-based RPDs, and that the denture base material may be a critical factor which determines denture use.

Critical issues in overlay metrology

International Nuclear Information System (INIS)

Sullivan, Neal T.

2001-01-01

In this paper, following an overview of overlay metrology, the difficult relationship of overlay with device performance and yield is discussed and supported with several examples. This is followed by a discussion of the impending collision of metrology equipment performance and 'real' process tolerances for sub 0.18 um technologies. This convergence of tolerance and performance is demonstrated to lead to the current emergence of real-time overlay modeling in a feed-forward/feedback process environment and the associated metrology/sampling implications. This modeling takes advantage of the wealth of understanding concerning the systematic behavior of overlay registration errors. Finally, the impact of new process technologies (RET, OAI, CPSM, CMP, and etc.) on the measurement target is discussed and shown to de-stabilize overlay performance on standard overlay measurement target designs

Denture-related oral mucosal lesions among removable denture wearers ‎referred to clinics of Kerman, Iran

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Shahrzad Taheri

2016-05-01

CONCLUSION: The finding of this study showed the prevalence of denture-related mucosal lesions is common. Dentists should be instruct the patients for removing the denture at night and routine follow-up visits.

[Study on retention and stability of linear occlusal complete dentures].

Science.gov (United States)

Zhang, Ping; Xu, Jun

2003-01-01

To learn retention and stability of linear occlusal complete dentures by investigating the subjective feelings of patient and the value of retention force. Static retention forces of maxillary and mandibular dentures were measured for 25 patients wearing linear occlusal dentures by using Hz-1 retention dynamometer. The subjective feelings of patients in functional state were gained simultaneously through questionnaire. Linear occlusal dentures demonstrate good retention in static and dynamic state. Among patients with severe resorption of residual ridge (RRR), mandibular linear occlusal dentures (shown good retentive subjective feelings) demonstrate significantly smaller retention force than those with slight or medium degree of RRR. There is no correlation between the subjective feelings and the values of retention forces of mandibular dentures. The subjective feelings of patients wearing new linear occlusal dentures are much better than that of old anatomic occlusal dentures. Linear occlusal dentures improve the performances of dentures by enhancing their stability during mastication movement.

Quantitative Estimation of Yeast on Maxillary Denture in Patients with Denture Stomatitis and the Effect of Chlorhexidine Gluconate in Reduction of Yeast

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Jaykumar R Gade

2011-01-01

Full Text Available Denture stomatitis is a condition associated with wearing of a denture. The predisposing factor leading to denture stomatitis could be poor oral hygiene, ill-fitting denture and relief areas. Around 30 patients with denture stomatitis were advised to rinse with chlorhexidine gluconate mouthwash for 14 days and were directed to immerse the upper denture in the chlorhexidine solution for 8 hours. The samples were collected by scraping maxillary denture in saline at three intervals, prior to, at the end of 24 hours and after 14 days of treatment, then were inoculated and quantitative estimation of the yeast growth on Sabouraud′s dextrose agar plate was done. It was observed that after a period of 14 days, there was a reduction in the growth of yeast and also improvement in the clinical picture of the oral mucosa

Comparative evaluation of the effect of denture cleansers on the surface topography of denture base materials: An in-vitro study.

Science.gov (United States)

Jeyapalan, Karthigeyan; Kumar, Jaya Krishna; Azhagarasan, N S

2015-08-01

The aim was to evaluate and compare the effects of three chemically different commercially available denture cleansing agents on the surface topography of two different denture base materials. Three chemically different denture cleansers (sodium perborate, 1% sodium hypochlorite, 0.2% chlorhexidine gluconate) were used on two denture base materials (acrylic resin and chrome cobalt alloy) and the changes were evaluated at 3 times intervals (56 h, 120 h, 240 h). Changes from baseline for surface roughness were recorded using a surface profilometer and standard error of the mean (SEM) both quantitatively and qualitatively, respectively. Qualitative surface analyses for all groups were done by SEM. The values obtained were analyzed statistically using one-way ANOVA and paired t-test. All three denture cleanser solutions showed no statistically significant surface changes on the acrylic resin portions at 56 h, 120 h, and 240 h of immersion. However, on the alloy portion changes were significant at the end of 120 h and 240 h. Of the three denture cleansers used in the study, none produced significant changes on the two denture base materials for the short duration of immersion, whereas changes were seen as the immersion periods were increased.

Overlay metrology for double patterning processes

Science.gov (United States)

Leray, Philippe; Cheng, Shaunee; Laidler, David; Kandel, Daniel; Adel, Mike; Dinu, Berta; Polli, Marco; Vasconi, Mauro; Salski, Bartlomiej

2009-03-01

The double patterning (DPT) process is foreseen by the industry to be the main solution for the 32 nm technology node and even beyond. Meanwhile process compatibility has to be maintained and the performance of overlay metrology has to improve. To achieve this for Image Based Overlay (IBO), usually the optics of overlay tools are improved. It was also demonstrated that these requirements are achievable with a Diffraction Based Overlay (DBO) technique named SCOLTM [1]. In addition, we believe that overlay measurements with respect to a reference grid are required to achieve the required overlay control [2]. This induces at least a three-fold increase in the number of measurements (2 for double patterned layers to the reference grid and 1 between the double patterned layers). The requirements of process compatibility, enhanced performance and large number of measurements make the choice of overlay metrology for DPT very challenging. In this work we use different flavors of the standard overlay metrology technique (IBO) as well as the new technique (SCOL) to address these three requirements. The compatibility of the corresponding overlay targets with double patterning processes (Litho-Etch-Litho-Etch (LELE); Litho-Freeze-Litho-Etch (LFLE), Spacer defined) is tested. The process impact on different target types is discussed (CD bias LELE, Contrast for LFLE). We compare the standard imaging overlay metrology with non-standard imaging techniques dedicated to double patterning processes (multilayer imaging targets allowing one overlay target instead of three, very small imaging targets). In addition to standard designs already discussed [1], we investigate SCOL target designs specific to double patterning processes. The feedback to the scanner is determined using the different techniques. The final overlay results obtained are compared accordingly. We conclude with the pros and cons of each technique and suggest the optimal metrology strategy for overlay control in double

In vitro comparison of the tensile bond strength of denture adhesives on denture bases.

Science.gov (United States)

Kore, Doris R; Kattadiyil, Mathew T; Hall, Dan B; Bahjri, Khaled

2013-12-01

With several denture adhesives available, it is important for dentists to make appropriate patient recommendations. The purpose of this study was to evaluate the tensile bond strength of denture adhesives on denture base materials at time intervals of up to 24 hours. Fixodent, Super Poligrip, Effergrip, and SeaBond denture adhesives were tested with 3 denture base materials: 2 heat-polymerized (Lucitone 199 and SR Ivocap) and 1 visible-light-polymerized (shade-stable Eclipse). Artificial saliva with mucin was used as a control. Tensile bond strength was tested in accordance with American Dental Association specifications at 5 minutes, 3 hours, 6 hours, 12 hours, and 24 hours after applying the adhesive. Maximum forces before failure were recorded in megapascals (MPa), and the data were subjected to a 2-way analysis of variance (α=.05). All 4 adhesives had greater tensile bond strength than the control. Fixodent, Super Poligrip, and SeaBond had higher tensile bond strength values than Effergrip. All adhesives had the greatest tensile bond strength at 5 minutes and the least at 24 hours. The 3 denture bases produced significantly different results with each adhesive (Padhesives had the greatest tensile bond strength, followed by Ivocap and Eclipse. All 4 adhesives had greater tensile bond strength than the control, and all 4 adhesives were strongest at the 5-minute interval. On all 3 types of denture bases, Effergrip produced significantly lower tensile bond strength, and Fixodent, Super Poligrip, and SeaBond produced significantly higher tensile bond strength. At 24 hours, the adhesive-base combinations with the highest tensile bond strength were Fixodent on Lucitone 199, Fixodent on Eclipse, Fixodent on Ivocap, and Super Poligrip on Ivocap. Copyright © 2013 Editorial Council for the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Liquid supported denture-management of flabby ridges

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Pranav V Mody

2012-01-01

Full Text Available The ideal properties of a denture are adequate rigidity on polished surface to bear masticatory forces and at the same time, flexibility and softness on the tissue surface for proper and even distribution of masticatory forces. The problem with conventional denture is rigidity of tissue surface; leads to uneven distribution of load. This drawback even worsens in the case of flabby, atrophic and unemployed ridges with excessive bone resorption.The liquid supported denture allows continued adaptation and eliminates the disadvantages of denture designs based on the application of temporary tissue conditioners or soft liners.

Diffraction based overlay re-assessed

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Leray, Philippe; Laidler, David; D'havé, Koen; Cheng, Shaunee

2011-03-01

In recent years, numerous authors have reported the advantages of Diffraction Based Overlay (DBO) over Image Based Overlay (IBO), mainly by comparison of metrology figures of merit such as TIS and TMU. Some have even gone as far as to say that DBO is the only viable overlay metrology technique for advanced technology nodes; 22nm and beyond. Typically the only reported drawback of DBO is the size of the required targets. This severely limits its effective use, when all critical layers of a product, including double patterned layers need to be measured, and in-die overlay measurements are required. In this paper we ask whether target size is the only limitation to the adoption of DBO for overlay characterization and control, or are there other metrics, which need to be considered. For example, overlay accuracy with respect to scanner baseline or on-product process overlay control? In this work, we critically re-assess the strengths and weaknesses of DBO for the applications of scanner baseline and on-product process layer overlay control. A comprehensive comparison is made to IBO. For on product process layer control we compare the performance on critical process layers; Gate, Contact and Metal. In particularly we focus on the response of the scanner to the corrections determined by each metrology technique for each process layer, as a measure of the accuracy. Our results show that to characterize an overlay metrology technique that is suitable for use in advanced technology nodes requires much more than just evaluating the conventional metrology metrics of TIS and TMU.

[Acrylic resin removable partial dentures

NARCIS (Netherlands)

Baat, C. de; Witter, D.J.; Creugers, N.H.J.

2011-01-01

An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

Comparative analysis of unilateral removable partial denture and classical removable partial denture by using finite element method

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Radović Katarina

2010-01-01

Full Text Available Introduction. Various mobile devices are used in the therapy of unilateral free-end saddle. Unilateral dentures with precise connectivity elements are not used frequently. In this paper the problem of applying and functionality of unilateral freeend saddle denture without major connector was taken into consideration. Objective. The aim was to analyze and compare a unilateral RPD (removable partial denture and a classical RPD by calculating and analyzing stresses under different loads. Methods. 3D models of unilateral removable partial denture and classical removable partial denture with casted clasps were made by using computer program CATIA V5 (abutment teeth, canine and first premolar, with crowns and abutment tissues were also made. The models were built in full-scale. Stress analyses for both models were performed by applying a force of 300 N on the second premolar, a force of 500 N on the first molar and a force of 700 N on the second molar. Results. The Fault Model Extractor (FME analysis and calculation showed the complete behavior of unilateral removable partial denture and abutments (canine and first premolar, as well as the behavior of RPD under identical loading conditions. Applied forces with extreme values caused high stress levels on both models and their abutments within physiological limits. Conclusion. Having analyzed stresses under same conditions, we concluded that the unilateral RPD and classical RPD have similar physiological values.

Overlay networks toward information networking

CERN Document Server

Tarkoma, Sasu

2010-01-01

With their ability to solve problems in massive information distribution and processing, while keeping scaling costs low, overlay systems represent a rapidly growing area of R&D with important implications for the evolution of Internet architecture. Inspired by the author's articles on content based routing, Overlay Networks: Toward Information Networking provides a complete introduction to overlay networks. Examining what they are and what kind of structures they require, the text covers the key structures, protocols, and algorithms used in overlay networks. It reviews the current state of th

VT Data - Overlay District 20170710, South Burlington

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Vermont Center for Geographic Information — Overlay data for the City of South Burlington included in this data:Flood Plain Overlay DistrictTraffic Overlay DistrictInterstate Highway Overlay DistrictScenic...

21 CFR 872.3580 - Preformed gold denture tooth.

Science.gov (United States)

2010-04-01

... tooth in a fixed or removable partial denture. (b) Classification. Class I (general controls). The... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Preformed gold denture tooth. 872.3580 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a...

Controlling fungal biofilms with functional drug delivery denture biomaterials.

Science.gov (United States)

Wen, Jianchuan; Jiang, Fuguang; Yeh, Chih-Ko; Sun, Yuyu

2016-04-01

Candida-associated denture stomatitis (CADS), caused by colonization and biofilm-formation of Candida species on denture surfaces, is a significant clinical concern. We show here that modification of conventional denture materials with functional groups can significantly increase drug binding capacity and control drug release rate of the resulting denture materials for potentially managing CADS. In our approach, poly(methyl methacrylate) (PMMA)-based denture resins were surface grafted with three kinds of polymers, poly(1-vinyl-2-pyrrolidinone) (PNVP), poly(methacrylic acid) (PMAA), and poly(2-hydroxyethyl methacrylate) (PHEMA), through plasma-initiated grafting polymerization. With a grafting yield as low as 2 wt%, the three classes of new functionalized denture materials showed significantly higher drug binding capacities toward miconazole, a widely used antifungal drug, than the original PMMA denture resin control, leading to sustained drug release and potent biofilm-controlling effects against Candida. Among the three classes of functionalized denture materials, PNVP-grafted resin provided the highest miconazole binding capability and the most powerful antifungal and biofilm-controlling activities. Drug binding mechanisms were studied. These results demonstrated the importance of specific interactions between drug molecules and functional groups on biomaterials, shedding lights on future design of CADS-managing denture materials and other related devices for controlled drug delivery. Copyright © 2015 Elsevier B.V. All rights reserved.

Candida albicans importance to denture wearers. A literature review.

Science.gov (United States)

Gleiznys, Alvydas; Zdanavičienė, Eglė; Žilinskas, Juozas

2015-01-01

Opportunistic oral fungal infections have spred, especially in denture wearers. Denture stomatitis is a common inflammatory reaction, multifactorial etiology, which is usually associated with Candida species, particularly Candida albicans, due to its high virulence, ability to adhere and form biofilms on oral cavity tissues and denture surfaces. This article highlights the pathogenesis, clinical presentation, and management strategies of Candida-associated denture stomatitis commonly encountered in dental practice.

Advanced overlay analysis through design based metrology

Science.gov (United States)

Ji, Sunkeun; Yoo, Gyun; Jo, Gyoyeon; Kang, Hyunwoo; Park, Minwoo; Kim, Jungchan; Park, Chanha; Yang, Hyunjo; Yim, Donggyu; Maruyama, Kotaro; Park, Byungjun; Yamamoto, Masahiro

2015-03-01

As design rule shrink, overlay has been critical factor for semiconductor manufacturing. However, the overlay error which is determined by a conventional measurement with an overlay mark based on IBO and DBO often does not represent the physical placement error in the cell area. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion caused by etching or CMP also can be a source of the mismatch. In 2014, we have demonstrated that method of overlay measurement in the cell area by using DBM (Design Based Metrology) tool has more accurate overlay value than conventional method by using an overlay mark. We have verified the reproducibility by measuring repeatable patterns in the cell area, and also demonstrated the reliability by comparing with CD-SEM data. We have focused overlay mismatching between overlay mark and cell area until now, further more we have concerned with the cell area having different pattern density and etch loading. There appears a phenomenon which has different overlay values on the cells with diverse patterning environment. In this paper, the overlay error was investigated from cell edge to center. For this experiment, we have verified several critical layers in DRAM by using improved(Better resolution and speed) DBM tool, NGR3520.

Effect of microwave cured acrylic resin on candidal growth in complete denture

International Nuclear Information System (INIS)

Rasmy, A.H.M.

2009-01-01

This study was conducted to evaluate the effect of heat-cured acrylic resin denture base and microwave-cured acrylic resin denture base on candidal growth . Seven completely edentulous male patients with on history of denture wearing participated in this study. all the selected patients were re-habilitated by mucosa supported complete dentures .The dentures were constructed from conventional heat-cured acrylic resin denture base following monoplane concept of occlusion. Before dismissing the patients and one month after denture insertion, salivary samples were collected according to oral rinse technique. one month resting period was allowed so as candidal count can reach to normal, then dentures were re based using microwave-cured acrylic denture base, before denture insertion and one month after denture insertion, salivary sample were collected before and one month following the same oral rinse technique.

Clinical evaluation of failures in removable partial dentures.

Science.gov (United States)

Jorge, Janaina H; Quishida, Cristiane C C; Vergani, Carlos E; Machado, Ana L; Pavarina, Ana C; Giampaolo, Eunice T

2012-01-01

The aim of this clinical study was to evaluate the effects of removable partial dentures on the support tissues and changes occurring in lower tooth-supported and bilateral distal-extension dentures, 5 years after placement. The study involved analysis of a total of 53 patients who received prosthetic treatment for removable partial dentures. The patients were divided into two groups. In group 1, the patients had a completely edentulous maxilla and an edentulous area with natural teeth remaining in both the anterior and posterior regions. In group 2, the patients had a completely edentulous maxilla and partially edentulous mandible with preserved anterior teeth. Tooth mobility, prevalence of caries, fracture of the abutment teeth, fracture and/or deformation of the removable partial denture components and stability of the denture base were evaluated. The use of a removable partial denture increased tooth mobility, reduced the prevalence of caries, and did not cause loss or fracture of the abutments or damage to their components, when compared with the baseline. It was concluded that there was no difference between the groups as evaluated in terms of tooth mobility, prevalence of caries, loss and fracture of the abutments or damage to the components of the removable partial denture.

Comparison of the Effect of two Denture Cleansers on Tensile bond Strength of a Denture Liner.

Science.gov (United States)

Farzin, M; Bahrani, F; Adelpour, E

2013-09-01

One of the most clinical challenging issues in prosthodontics is debonding of soft liners from the denture base. The aim of this study was to evaluate and compare tensile bond strength between soft liner and heat-cured acrylic resin when immersed in two different types of denture cleanser and distilled water, at different period of times. In this experimental in vivo study, 238 heat-cured acrylic blocks were made. A soft liner was embedded between the acrylic blocks. Samples were divided into four groups: 17 samples were in the control group and were not soaked in any solution .The remaining samples were divided into 3 groups (Distilled water, Calgon and Fittydent). Each group was then subdivided into two subcategories, regarding the immersion time variable; 15 and 45 minutes. All samples were placed in tension force and tensile bond strength was recorded with the testing machine. One- way ANOVA and Tucky HSD post-hoc test were adopted to analyze the yielded data (α> 0.05). Specimens which were immersed in two denture cleansers (Fittydent and Calgon) and in distilled water showed significant difference (p= 0.001) in bonding strength when compared to the control group. The subjects immersed in denture cleanser solutions and distilled water did not reveal any significant difference (p= 0.90). For all groups; most of the bonding failures (72%) were cohesive type. The effect of the denture cleansers and distilled water on the bond strength was not statistically different; however, the difference was significant between the immersed groups with the non-immersed group. Moreover, type of the denture cleanser did not show any effect on the tensile strength. The tensile strength increases with time of immersion.

[Designing metal frame removable partial dentures

NARCIS (Netherlands)

Witter, D.J.; Barel, J.C.; Keltjens, H.M.A.M.; Creugers, N.H.J.

2011-01-01

Oral health care providers have the full responsibility for designing metal frame removable partial dentures and making all of the necessary preparations. Important principles of design are that the denture should hamper natural cleaning and daily oral hygiene as little as possible and that it

Light weight hollow maxillary complete denture: A case series

Directory of Open Access Journals (Sweden)

Laxman Singh Kaira

2012-01-01

Full Text Available Retention, stability and support are the basic principles on which the success of a complete denture relies on. The skill lies in applying these principles efficiently in critical situations. Residual ridge resorption occurs at a three times faster rate in mandibular arch than in the maxillary arch. The severely resorbed maxillary and mandibular edentulous arches that are narrow and constricted with increased interarch space provide decreased support, retention and stability. The consequent weight of the processed complete denture only compromises them further. The severely resorbed jaw can have various treatment options. Extreme resorption of the maxillary denture-bearing area may lead to problems with prosthetic rehabilitation. The advantage of a hollow maxillary or mandibular denture is the reduction of excessive weight of acrylic resin, which normally replaces lost alveolar ridge in the interridge space of the denture wearer. This clinical report describes two case reports of edentulous patients with resorbed ridges where a simplified technique of fabricating a light weight hollow maxillary complete denture was used for the preservation of denture bearing areas.

Denture hyperplasia with areas simulating oral inverted ductal papilloma.

Science.gov (United States)

Vargas, Pablo Agustin; Perez, Danyel Elias da Cruz; Jorge, Jacks; Rangel, Ana Lúcia Carrinho Ayrosa; León, Jorge Esquiche; Almeida, Oslei Paes de

2005-07-01

Denture hyperplasia is a reactive lesion of the oral mucosa, usually associated to an ill-fitting denture. This lesion is easily diagnosed and in some cases distinct microscopic variations such as osseous, oncocytic and squamous metaplasia may be found. These metaplastic alterations probably are associated with the lymphocytic infiltrate usually present in denture hyperplasia. We present a case of denture hyperplasia containing salivary gland tissue with ductal alterations mimicking an oral inverted ductal papilloma.

Elderly complete denture wearers: a social approach to tooth loss.

Science.gov (United States)

Papadaki, Eftychia; Anastassiadou, Vassiliki

2012-06-01

To correlate emotional reactions to tooth loss with denture satisfaction attributes in elderly complete denture wearers. Total tooth loss is a serious life event, and poor oral health has an impact on daily life. Edentulism treated by rehabilitation with dentures can have a positive effect on patients' self-image and social behaviour. A group of 80 edentulous subjects undergoing routine prosthetic care in a Greek Department of Prosthetic Dentistry were interviewed using two structured questionnaires. The first questionnaire explored reactions to tooth loss, whereas the second measured their subjective experience of complete dentures. The responses to both questionnaires were compared using the statistical package SPSS v.17. The results showed significant correlation between aspects of tooth loss experience and complete denture satisfaction. Despite the fact that a substantial proportion of patients were satisfied with their complete dentures, some patients experienced increased social and psychological problems related to their edentulousness and the wearing of complete dentures. The aesthetic and functional aspects of complete dentures affected both patients' social behaviour and self-confidence. Total tooth loss was not only reflected in patient's social behaviour and self-image, but it had a complex and multifaceted impact on satisfaction from complete dentures. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

Evaluation of Prevalence of Oral Candidiasis in Patients Using Complete Denture Wears

Directory of Open Access Journals (Sweden)

P Tavakkol

2001-06-01

Full Text Available Denture stomatotos os a common problem of the denture wears, and its etiology is not clear from the literatures. Some studies show that the aetiology is candida albicans, while other reports point out the other agents including candida albicans. The present study was designed to evaluate the prevalence of oral candidiasis in patients using complete denture with different datas. 50 subjects all wearing complete denture participated in this study. The palatal mucosa was swabbed and swabs were cultured in Sabourauds medium containing 0.005% chloramphenicol then cultures were tested with common mycological lab tests. In 80% of patients oral candidiasis have been diagnosed. In the investigation a direct relation between the oral candidiasis and removal of denture at night, denture cleanliness, presence of any suction and symptoms of denture stomatitis was shown. No relation between the oral candidiasis and sex, smoking habit, succeptible disease, angular cheilitis; the recent condition of denture and the retention of denture were found. The findings of our investigation indicates that candida albicans is the causative agent of denture stomatitis while other factors such as denture cleanliness, removal of denture at night and presence of any suction may be considered as well.

Successful removable partial dentures.

Science.gov (United States)

Lynch, Christopher D

2012-03-01

Removable partial dentures (RPDs) remain a mainstay of prosthodontic care for partially dentate patients. Appropriately designed, they can restore masticatory efficiency, improve aesthetics and speech, and help secure overall oral health. However, challenges remain in providing such treatments, including maintaining adequate plaque control, achieving adequate retention, and facilitating patient tolerance. The aim of this paper is to review the successful provision of RPDs. Removable partial dentures are a successful form of treatment for replacing missing teeth, and can be successfully provided with appropriate design and fabrication concepts in mind.

A clinical evaluation denture adhesives used by patients with xerostomia.

Science.gov (United States)

Bogucki, Zdzislaw A; Napadlek, Piotr; Dabrowa, Tomasz

2015-02-01

The purpose of study was to analyze the participants' opinions concerning the effectiveness of 6 denture adhesives (DA). The study group included 60 participants. Criteria for selecting the patients were as follows: reduced retention and stabilization of maxillary complete dentures and xerostomia. These features were evaluated on basis of clinical examination and standard sialometry tests (u-SFR). Retention of maxillary dentures was scored by modified Kapur index before application of DA. All participants were divided randomly into 6 groups regarding the use of the 6 DA during a 6-month period. After this time, participants completed an HRQL questionnaire. DA noticeably improved retention and stabilization of maxillary complete dentures. DA in the glue form had the best retention effectiveness in participants with xerostomia. These materials are difficult to clean from the denture base. The data are presented in tables and figures. The results of the study collected positive influence of adhesives on retention of dentures in xerostomia patients. The cleaning dentures and denture bearing tissues was difficult. DA help in the use of prostheses, but it is also necessary for the treatment of the causes and symptoms of xerostomia.

Design of Complete Dentures by Adopting CAD Developed for Fixed Prostheses.

Science.gov (United States)

Li, Yanfeng; Han, Weili; Cao, Jing; Iv, Yuan; Zhang, Yue; Han, Yishi; Shen, Yi; Ma, Zheng; Liu, Huanyue

2018-02-01

The demand for complete dentures is expected to increase worldwide, but complete dentures are mainly designed and fabricated manually involving a broad series of clinical and laboratory procedures. Therefore, the quality of complete dentures largely depends on the skills of the dentist and technician, leading to difficulty in quality control. Computer-aided design and manufacturing (CAD/CAM) has been used to design and fabricate various dental restorations including dental inlays, veneers, crowns, partial crowns, and fixed partial dentures (FPDs). It has been envisioned that the application of CAD/CAM technology could reduce intensive clinical/laboratory work for the fabrication of complete dentures; however, CAD/CAM is seldom used to fabricate complete dentures due to the lack of suitable CAD software to design virtual complete dentures although the CAM techniques are in a much advanced stage. Here we report the successful design of virtual complete dentures using CAD software of 3Shape Dental System 2012, which was developed for designing fixed prostheses instead of complete dentures. Our results demonstrated that complete dentures could be successfully designed by the combination of two modeling processes, single coping and full anatomical FPD, available in the 3Shape Dental System 2012. © 2016 by the American College of Prosthodontists.

Alveolar ridge rehabilitation to increase full denture retention and stability

OpenAIRE

Mefina Kuntjoro; Rostiny Rostiny; Wahjuni Widajati

2010-01-01

Background: Atrophic mandibular alveolar ridge generally complicates prostetic restoration expecially full denture. Low residual alveolar ridge and basal seat can cause unstable denture, permanent ulcer, pain, neuralgia, and mastication difficulty. Pre-proshetic surgery is needed to improve denture retention and stability. Augmentation is a major surgery to increase vertical height of the atrophic mandible while vestibuloplasty is aimed to increase the denture bearing area. Purpose: The augme...

21 CFR 872.3300 - Hydrophilic resin coating for dentures.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hydrophilic resin coating for dentures. 872.3300... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3300 Hydrophilic resin coating for dentures. (a) Identification. A hydrophilic resin coating for dentures is a device that consists of a water...

The adhesive strength and initial viscosity of denture adhesives.

Science.gov (United States)

Han, Jian-Min; Hong, Guang; Dilinuer, Maimaitishawuti; Lin, Hong; Zheng, Gang; Wang, Xin-Zhi; Sasaki, Keiichi

2014-11-01

To examine the initial viscosity and adhesive strength of modern denture adhesives in vitro. Three cream-type denture adhesives (Poligrip S, Corect Cream, Liodent Cream; PGS, CRC, LDC) and three powder-type denture adhesives (Poligrip Powder, New Faston, Zanfton; PGP, FSN, ZFN) were used in this study. The initial viscosity was measured using a controlled-stress rheometer. The adhesive strength was measured according to ISO-10873 recommended procedures. All data were analyzed independently by one-way analysis of variance combined with a Student-Newman-Keuls multiple comparison test at a 5% level of significance. The initial viscosity of all the cream-type denture adhesives was lower than the powder-type adhesives. Before immersion in water, all the powder-type adhesives exhibited higher adhesive strength than the cream-type adhesives. However, the adhesive strength of cream-type denture adhesives increased significantly and exceeded the powder-type denture adhesives after immersion in water. For powder-type adhesives, the adhesive strength significantly decreased after immersion in water for 60 min, while the adhesive strength of the cream-type adhesives significantly decreased after immersion in water for 180 min. Cream-type denture adhesives have lower initial viscosity and higher adhesive strength than powder type adhesives, which may offer better manipulation properties and greater efficacy during application.

[Oral mucosa reaction in patients adapting to removable dentures].

Science.gov (United States)

Iordanishvili, A K; Soldatova, L N; Pihur, O L; Mihajlova, E S; Peremyshlenko, A S; Soldatov, V S

Oral mucosa reaction of prosthetic bed to the removable acrylic dentures was evaluated in 43 patients (12 male and 31 female) aged 56-69 years with partial and full teeth loss in one or both jaws. Patients of the first (control) group (17 patients) were not using additional tools improving fixation of the removable dentures during adaptation period, while patients of the second (main) group (26 patients) used Corega cream for dentures fixation for 30 days follow-up. Oral mucosa assessment was carried out on 3-4 and 28-30 day of dentures use by 3 end points: pain syndrome, moisture level, inflammation of a prosthetic bed. The results proved Corega cream to improve prosthetic bed mucosa condition reducing inflammatory response to polymeric materials of removable dentures basis.

The effect of denture adhesives on Candida albicans growth in vitro.

Science.gov (United States)

Sampaio-Maia, Benedita; Figueiral, Maria Helena; Sousa-Rodrigues, Patricia; Fernandes, Maria Helena; Scully, Crispian

2012-06-01

Denture-wearing favours the growth of Candida. In view of the fact that many denture wearers regularly use adhesives to enhance denture retention, stability and function, the aim of this work was to study the effect of denture adhesives on Candida albicans growth in vitro. The denture adhesives tested were Corega(®) cream, Kukident(®) cream, Novafix(®) cream, Polident(®) cream, Protefix(®) cream, Steradent(®) cream, Aderyn(®) powder, Corega(®) ultra powder, Protefix(®) powder and Corega(®) strip. C. albicans growth curves were obtained in the presence or absence of a 1% solution of the denture adhesive diluted in Sabouraud broth. Macro- and microscopic morphological changes in C. albicans were analysed, as was microbial contamination of the denture adhesive. Most of the denture adhesives studied induced morphological changes in C. albicans cells and colonies, but only two had any significant inhibitory effect on yeast growth. Kukident(®) cream markedly inhibited C. albicans growth in a concentration-dependent way, reducing the growth rate by 95%, whereas Corega(®) cream also inhibited C. albicans growth but in a non-concentration-dependent way, reducing the growth rate by 37%. In addition, denture adhesives available as powders had detectable microbial contamination. Some commercially available denture adhesives showed microbial contamination and some had significant inhibitory effect on C. albicans growth. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

A simple approach to hollow maxillary complete denture fabrication: An innovative technique

Directory of Open Access Journals (Sweden)

Kathleen Manuela D'souza

2017-01-01

Full Text Available A severely atrophic maxillary arch exhibits reduced denture bearing area and increased inter-ridge distance, thus, affecting retention of the complete denture. Such clinical situations necessitate the fabrication of a hollow complete denture to reduce the weight of the prosthesis and increase retention. This article describes a simple technique to fabricate a hollow maxillary complete denture using salt and thermoplastic poly (methyl methacrylate sheet. The vacuum-formed thermoplastic matrix regulates the quantity of salt and determines its placement in the unpolymerized denture base material during the denture packing stage. The matrix lining the hollow cavity also aids to reinforce the hollow denture base.

Overlay accuracy with respect to device scaling

Science.gov (United States)

Leray, Philippe; Laidler, David; Cheng, Shaunee

2012-03-01

Overlay metrology performance is usually reported as repeatability, matching between tools or optics aberrations distorting the measurement (Tool induced shift or TIS). Over the last few years, improvement of these metrics by the tool suppliers has been impressive. But, what about accuracy? Using different target types, we have already reported small differences in the mean value as well as fingerprint [1]. These differences make the correctables questionable. Which target is correct and therefore which translation, scaling etc. values should be fed back to the scanner? In this paper we investigate the sources of these differences, using several approaches. First, we measure the response of different targets to offsets programmed in a test vehicle. Second, we check the response of the same overlay targets to overlay errors programmed into the scanner. We compare overlay target designs; what is the contribution of the size of the features that make up the target? We use different overlay measurement techniques; is DBO (Diffraction Based Overlay) more accurate than IBO (Image Based Overlay)? We measure overlay on several stacks; what is the stack contribution to inaccuracy? In conclusion, we offer an explanation for the observed differences and propose a solution to reduce them.

Manufacturing hollow obturator with resilient denture liner on post hemimaxillectomy

Directory of Open Access Journals (Sweden)

Michael Josef Kridanto Kamadjaja

2006-03-01

Full Text Available A resilient denture liner is placed in the part of the hollow obturator base that contacts to post hemimaxillectomy mucosa. Replacing the resilient denture liner can makes the hollow obturator has an intimate contact with the mucosa, so it can prevents the mouth liquid enter to the cavum nasi and sinus, also eliminates painful because of using the hollow obturator. Resilient denture liner is a soft and resilient material that applied to the fitting surface of a denture in order to allow a more distribution of load. A case was reported about using the hollow obturator with resilient denture liner on post hemimaxillectomy to overcome these problems.

Different types of antagonists modify the outcome of complete denture renewal.

Science.gov (United States)

Berteretche, Marie Violaine; Frot, Amélie; Woda, Alain; Pereira, Bruno; Hennequin, Martine

2015-01-01

The effect of renewing removable dentures on masticatory function was evaluated according to the occlusion offered by different types of mandibular arches. Twenty-eight patients with complete maxillary dentures were subdivided into three groups in terms of mandibular dentition type: dentate, partial denture, and complete denture. The participants were observed before and 8 weeks after maxillary denture renewal. The mandibular denture was also renewed in the partial and complete denture groups. The participants masticated carrots, peanuts, and three model foods of different hardnesses. The particle size distribution of the boluses obtained from natural foods was characterized by the median particle size (d50) in relation to the masticatory normative indicator (MNI). Chewing time (CT), number of chewing cycles (CC), and chewing frequency (CF) were video recorded. A self-assessment questionnaire for oral health-related quality of life (Geriatric Oral Health Assessment Index [GOHAI]) was used. Statistical analyses were carried out with a mixed model. Renewal of the dentures decreased d50 (P < .001). The number of participants with d50 values above the MNI cutoff decreased from 12 to 2 after renewal. Renewal induced an increase in mean CF while chewing model foods (P < .001). With all foods, renewal tended to affect CT, CC, and CF differently among the three groups (statistically significant renewal Å~ group interactions). The GOHAI score increased significantly for all groups. Denture renewal improves masticatory function. The complete denture group benefited least from renewal; the dentate group benefited most. This study confirmed the usefulness of denture renewal for improving functions and oral health- related quality of life.

Oral health-related quality of life in patients treated by implant-supported fixed dentures and removable partial dentures.

Science.gov (United States)

Furuyama, Chisako; Takaba, Masayuki; Inukai, Mika; Mulligan, Roseann; Igarashi, Yoshimasa; Baba, Kazuyoshi

2012-08-01

This study investigated the association between denture status [implant-supported fixed dentures (IDs) and removable partial dentures (RPDs)] and oral health-related quality of life (OHRQoL). Consecutive patients with IDs and RPDs were recruited from the Prosthodontics Departments at Showa University and Tokyo Medical and Dental University. The Japanese version of the Oral Health Impact Profile (OHIP-J-49) was administered to each subject. For each OHIP-J-49 question, the subjects were asked to indicate the frequency with which they had experienced a dental problem during the last month. Responses were recorded on a 5 point Likert rating scale, with 0 being never and 4, very often. Summary scores were calculated and regression analyses conducted to investigate the association between denture status and OHIP-J-49 summary score. In total 79 ID subjects (mean age±SD of 51.7±12.4 years, 44.3% men) and 109 RPD subjects (mean age of 66.5±8.6 years, 30% men) participated after giving informed consent. The regression analysis between the type of treatment and the OHIP-J-49 summary score revealed a significant association with a coefficient of 17.0 (Confidence interval, CI: 10.9-23.1). When age and duration of denture usage, which had significant associations with OHIP-J-49, were included in this model, the regression coefficient remained virtually unchanged at 17.4 (CI: 9.75-25.0), thus indicating little potential confounding by them. OHRQoL in patients with implant-supported fixed dentures is generally less impaired than it is in those patients with RPDs. © 2011 John Wiley & Sons A/S.

Flexible removable partial dentures: a basic overview.

Science.gov (United States)

Hill, Edward E; Rubel, Barry; Smith, John B

2014-01-01

For many years, flexible resin materials have been available for fabricating removable partial denture (RPD) prostheses. Using a nonrigid material for the major connector or other components of an RPD may be a consideration for certain patients. Except for the promotional literature that has been written for flexible resin dentures, there is very little information available in the dental literature concerning nonrigid RPDs. As a result, the decision to use this treatment option depends on the judgment and experience of the dentist and fabricating laboratory. This article summarizes clinically pertinent information about flexible, nonrigid partial dentures.

Trial of an experimental castor oil solution for cleaning dentures.

Science.gov (United States)

Andrade, Ingrid Machado de; Andrade, Kelly Machado de; Pisani, Marina Xavier; Silva-Lovato, Cláudia Helena; de Souza, Raphael Freitas; Paranhos, Helena de Freitas Oliveira

2014-01-01

Denture hygiene is essential because denture biofilm is involved in oral infections and systemic diseases. Although there are chemical agents available on the market, none of them have ideal properties and research on such products is still necessary. The aim of this study was to evaluate the efficacy of a castor bean (Ricinus communis)-based solution for removing denture biofilm, compared to two traditional products (sodium hypochlorite and alkaline peroxide). Fifty maxillary complete denture wearers were instructed to brush their dentures after meals and to immerse their dentures once a day in the following solutions: Saline (20 min; control), Polident alkaline peroxide (3 min), NaOCl (20 min) and 2% castor oil solution (20 min). Participants used each solution for a period of 7 consecutive days, according to a random sequence. After each period, the internal surfaces of maxillary complete dentures were stained with a disclosing solution (1% neutral red), photographed and the disclosed biofilm was quantified with the aid of specific software. The influence of treatments on results was verified by the Friedman test (α=0.05). Tested solutions presented significant difference (Fr=51.67; pcastor oil presented intermediate results (median: 1.0% and 1.5%, respectively). It can be concluded that the castor oil solution tested in this study was comparable to alkaline peroxide in terms of efficiency in denture biofilm removal.

Comparison of denture tooth movement between CAD-CAM and conventional fabrication techniques.

Science.gov (United States)

Goodacre, Brian J; Goodacre, Charles J; Baba, Nadim Z; Kattadiyil, Mathew T

2018-01-01

Data comparing the denture tooth movement of computer-aided design and computer-aided manufacturing (CAD-CAM) and conventional denture processing techniques are lacking. The purpose of this in vitro study was to compare the denture tooth movement of pack-and-press, fluid resin, injection, CAD-CAM-bonded, and CAD-CAM monolithic techniques for fabricating dentures to determine which process produces the most accurate and reproducible prosthesis. A total of 50 dentures were evaluated, 10 for each of the 5 groups. A master denture was fabricated and milled from prepolymerized poly(methyl methacrylate). For the conventional processing techniques (pack-and-press, fluid resin, and injection) a polyvinyl siloxane putty mold of the master denture was made in which denture teeth were placed and molten wax injected. The cameo surface of each wax-festooned denture was laser scanned, resulting in a standard tessellation language (STL) format file. The CAD-CAM dentures included 2 subgroups: CAD-CAM-bonded teeth in which the denture teeth were bonded into the milled denture base and CAD-CAM monolithic teeth in which the denture teeth were milled as part of the denture base. After all specimens had been fabricated, they were hydrated for 24 hours, and the cameo surface laser scanned. The preprocessing and postprocessing scan files of each denture were superimposed using surface-matching software. Measurements were made at 64 locations, allowing evaluation of denture tooth movement in a buccal, lingual, mesial-distal, and occlusal direction. The use of median and interquartile range values was used to assess accuracy and reproducibility. Levene and Kruskal-Wallis analyses of variance were used to evaluate differences between processing techniques (α=.05). The CAD-CAM monolithic technique was the most accurate, followed by fluid resin, CAD-CAM-bonded, pack-and-press, and injection. CAD-CAM monolithic technique was the most reproducible, followed by pack-and-press, CAD

Removable partial denture on osseointegrated implants and natural teeth.

Science.gov (United States)

Chang, Li-Ching; Wang, Jen-Chyan; Tasi, Chi-Cheng

2007-01-01

Implants have been designed to provide edentulous patients with fixed prostheses or overdentures. Recently, implant-supported fixed partial prostheses and single crowns have become successful treatment alternatives to removable and fixed partial dentures. However, few researchers have examined "removable partial dentures on implants and natural teeth". In this article, we report two patients fitted with "removable partial dentures on implants and natural teeth". The patients were satisfied with their dentures in terms of function and aesthetics. Regular follow-up visits revealed that the periodontal and peri-implant conditions were stable. There was no evidence of excessive intrusion or mobility of the teeth, nor were any visible changes in the bone levels of the natural teeth or implants noted on radiographs. Since the average duration of observation was about 38 months, further follow-up examinations are necessary to determine whether these dentures remain stable long-term.

Reaching for the true overlay in advanced nodes

Science.gov (United States)

Koay, Chiew-seng; Hamieh, Bassem; Felix, Nelson; Gaudiello, John

2017-03-01

Traditionally, the total measurement uncertainty (TMU) of overlay metrology focuses on dynamic precision, toolinduced-shift, and matching, while rarely examining inaccuracy. However, some researchers have recently shown that measurement inaccuracy can still be large despite optimized small TMU. Moreover, this inaccuracy can consume a significant portion of the overlay budget in the advanced nodes. In addition to qualifying the overlay error of inline wafers, overlay metrology is also used for improving on-product overlay as it provides corrective feedback to the lithography scanner. The accuracy of the correction terms as a result depends directly upon the measurement accuracy. As such, enhanced overlay accuracy will improve the overlay performance of reworked wafers, or subsequently exposed wafers. We have previously shown that a segmented Blossom target is more prone to asymmetry-induced inaccuracy than a nonsegmented target is [1]. Since target segmentation is inevitable for SADP and SAQP patterning processes, their resulting overlay performance leaves a lot to be desired. In our quest to reach for the true overlay, this paper reports our investigations on accuracy enhancement techniques for image-based targets, such as redundancy and self-calibration, and on the use of simulation-optimized scatterometry-based targets.

Life extension of boilers using weld overlay protection

Energy Technology Data Exchange (ETDEWEB)

Lai, G; Hulsizer, P [Welding Services Inc., Norcross, GA (United States); Brooks, R [Welding Services Inc., Welding Services Europe, Spijkenisse (Netherlands)

1999-12-31

The presentation describes the status of modern weld overlay technology for refurbishment, upgrading and life extension of boilers. The approaches to life extension of boilers include field overlay application, shop-fabricated panels for replacement of the worn, corroded waterwall and shop-fabricated overlay tubing for replacement of individual tubes in superheaters, generating banks and other areas. The characteristics of weld overlay products are briefly described. Also discussed are successful applications of various corrosion-resistant overlays for life extension of boiler tubes in waste-to-energy boilers, coal-fired boilers and chemical recovery boilers. Types of corrosion and selection of weld overlay alloys in these systems are also discussed. (orig.) 14 refs.

Life extension of boilers using weld overlay protection

Energy Technology Data Exchange (ETDEWEB)

Lai, G.; Hulsizer, P. [Welding Services Inc., Norcross, GA (United States); Brooks, R. [Welding Services Inc., Welding Services Europe, Spijkenisse (Netherlands)

1998-12-31

The presentation describes the status of modern weld overlay technology for refurbishment, upgrading and life extension of boilers. The approaches to life extension of boilers include field overlay application, shop-fabricated panels for replacement of the worn, corroded waterwall and shop-fabricated overlay tubing for replacement of individual tubes in superheaters, generating banks and other areas. The characteristics of weld overlay products are briefly described. Also discussed are successful applications of various corrosion-resistant overlays for life extension of boiler tubes in waste-to-energy boilers, coal-fired boilers and chemical recovery boilers. Types of corrosion and selection of weld overlay alloys in these systems are also discussed. (orig.) 14 refs.

Performance of ASML YieldStar μDBO overlay targets for advanced lithography nodes C028 and C014 overlay process control

Science.gov (United States)

Blancquaert, Yoann; Dezauzier, Christophe; Depre, Jerome; Miqyass, Mohamed; Beltman, Jan

2013-04-01

Continued tightening of overlay control budget in semiconductor lithography drives the need for improved metrology capabilities. Aggressive improvements are needed for overlay metrology speed, accuracy and precision. This paper is dealing with the on product metrology results of a scatterometry based platform showing excellent production results on resolution, precision, and tool matching for overlay. We will demonstrate point to point matching between tool generations as well as between target sizes and types. Nowadays, for the advanced process nodes a lot of information is needed (Higher order process correction, Reticle fingerprint, wafer edge effects) to quantify process overlay. For that purpose various overlay sampling schemes are evaluated: ultra- dense, dense and production type. We will show DBO results from multiple target type and shape for on product overlay control for current and future node down to at least 14 nm node. As overlay requirements drive metrology needs, we will evaluate if the new metrology platform meets the overlay requirements.

Enhacement of intrafield overlay using a design based metrology system

Science.gov (United States)

Jo, Gyoyeon; Ji, Sunkeun; Kim, Shinyoung; Kang, Hyunwoo; Park, Minwoo; Kim, Sangwoo; Kim, Jungchan; Park, Chanha; Yang, Hyunjo; Maruyama, Kotaro; Park, Byungjun

2016-03-01

As the scales of the semiconductor devices continue to shrink, accurate measurement and control of the overlay have been emphasized for securing more overlay margin. Conventional overlay analysis methods are based on the optical measurement of the overlay mark. However, the overlay data obtained from these optical methods cannot represent the exact misregistration between two layers at the circuit level. The overlay mismatch may arise from the size or pitch difference between the overlay mark and the real pattern. Pattern distortion, caused by CMP or etching, could be a source of the overlay mismatch as well. Another issue is the overlay variation in the real circuit pattern which varies depending on its location. The optical overlay measurement methods, such as IBO and DBO that use overlay mark on the scribeline, are not capable of defining the exact overlay values of the real circuit. Therefore, the overlay values of the real circuit need to be extracted to integrate the semiconductor device properly. The circuit level overlay measurement using CDSEM is time-consuming in extracting enough data to indicate overall trend of the chip. However DBM tool is able to derive sufficient data to display overlay tendency of the real circuit region with high repeatability. An E-beam based DBM(Design Based Metrology) tool can be an alternative overlay measurement method. In this paper, we are going to certify that the overlay values extracted from optical measurement cannot represent the circuit level overlay values. We will also demonstrate the possibility to correct misregistration between two layers using the overlay data obtained from the DBM system.

Overlay leaves litho: impact of non-litho processes on overlay and compensation

Science.gov (United States)

Ruhm, Matthias; Schulz, Bernd; Cotte, Eric; Seltmann, Rolf; Hertzsch, Tino

2014-10-01

According to the ITRS roadmap [1], the overlay requirement for the 28nm node is 8nm. If we compare this number with the performance given by tool vendors for their most advanced immersion systems (which is emerging. Mask contributions and so-called non-linear wafer distortions are known effects that can impact overlay quite significantly. Furthermore, it is often forgotten that downstream (post-litho) processes can impact the overlay as well. Thus, it can be required to compensate for the effects of subsequent processes already at the lithography operation. Within our paper, we will briefly touch on the wafer distortion topic and discuss the limitations of lithography compensation techniques such as higher order corrections versus solving the root cause of the distortions. The primary focus will be on the impact of the etch processes on the pattern placement error. We will show how individual layers can get affected differently by showing typical wafer signatures. However, in contrast to the above-mentioned wafer distortion topic, lithographic compensation techniques can be highly effective to reduce the placement error significantly towards acceptable levels (see Figure 1). Finally we will discuss the overall overlay budget for a 28nm contact to gate case by taking the impact of the individual process contributors into account.

Effect of Microwave Cured Acrylic Resin on Candidal Growth in Complete denture

International Nuclear Information System (INIS)

Rasmy, A.H.M.

2009-01-01

This study was conducted to evaluate the effect of heat-cured acrylic resin denture base and microwave-cured acrylic resin denture base on Candidal growth. Seven completely edentulous male patients with no history of denture wearing participated in this study. All the selected patients were re-habilitated by mucosa supported complete dentures. The dentures were constructed from conventional heat-cured acrylic resin denture base following monoplane concept of occlusion. Before dismissing the patients and one month after denture insertion, salivary samples were collected according to oral rinse technique. One month resting period was allowed so as Candidal count can reach to normal. Then dentures were re based using microwave-cured acrylic denture base, before denture insertion and one month after denture insertion, salivary sample were collected before and one month following the same oral rinse technique. In the oral rinse technique, the patients were instructed to rinse their mouths with 10 mL of sterile phosphate buffered saline for 60 seconds. The rinse was then expectorated into a universal container and immediately transported to the laboratory for concentration by centrifugation, then cultured on sabouraud's dextrose agar plates which were incubated at 37 degree C for 48 hours. Microscopic examination and germ tube test were carried out for laboratory investigations. In addition, the morphological features of the isolated Candida from the samples tested in this study, were investigated using the scanning electron microscope(SEM)

Lost and found…Tracking a swallowed denture: Role of radiology

Directory of Open Access Journals (Sweden)

Yogita Khalekar

2017-01-01

Full Text Available Denture ingestion or aspiration is a problem requiring awareness of different specialists including dentists, surgeons, otolaryngologists, and anesthesiologists for prevention, early diagnosis and adequate treatment. Complications of swallowed dentures include hollow viscous necrosis, perforation, and penetration to neighbouring organs leading to fistulae, bleeding and obstruction. Here, we present the case of a 65 year old female patient who swallowed the denture, which was detected by barium swallow and removed by endoscopy. Hence, the management of swallowed denture needs a multidisciplinary approach with the help of a dentist, otolaryngologist and anesthesiologists. Dentists should recommend patients to visit them for planned check ups or revisit them in case of denture dislodgement or loosening as soon as possible to prevent such life threatening events.

Expectations and satisfaction of denture patients in a university clinic.

Science.gov (United States)

Davis, E L; Albino, J E; Tedesco, L A; Portenoy, B S; Ortman, L F

1986-01-01

These results indicate that patients' expectations of dentures before treatment were unrealistically high and that informational videotapes did not significantly affect these expectations. Satisfaction with current dentures was surprisingly high before treatment and increased significantly from pretreatment to postreatment for both groups in the study. While it is likely that this increase in satisfaction reflects a change from poor to excellent denture status, this finding may also be attributed to cognitive dissonance theory; that is, high satisfaction may represent the means by which patients justify the expenses of their denture treatment. Although the videotape presentations did not alter the expectations of patients and their satisfaction with dentures, the tapes represent a potential source of accurate, standardized information for both patient and student dentist.

Advanced diffraction-based overlay for double patterning

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Li, Jie; Liu, Yongdong; Dasari, Prasad; Hu, Jiangtao; Smith, Nigel; Kritsun, Oleg; Volkman, Catherine

2010-03-01

Diffraction based overlay (DBO) technologies have been developed to address the tighter overlay control challenges as the dimensions of integrated circuit continue to shrink. Several studies published recently have demonstrated that the performance of DBO technologies has the potential to meet the overlay metrology budget for 22nm technology node. However, several hurdles must be cleared before DBO can be used in production. One of the major hurdles is that most DBO technologies require specially designed targets that consist of multiple measurement pads, which consume too much space and increase measurement time. A more advanced spectroscopic ellipsometry (SE) technology-Mueller Matrix SE (MM-SE) is developed to address the challenge. We use a double patterning sample to demonstrate the potential of MM-SE as a DBO candidate. Sample matrix (the matrix that describes the effects of the sample on the incident optical beam) obtained from MM-SE contains up to 16 elements. We show that the Mueller elements from the off-diagonal 2x2 blocks respond to overlay linearly and are zero when overlay errors are absent. This superior property enables empirical DBO (eDBO) using two pads per direction. Furthermore, the rich information in Mueller matrix and its direct response to overlay make it feasible to extract overlay errors from only one pad per direction using modeling approach (mDBO). We here present the Mueller overlay results using both eDBO and mDBO and compare the results with image-based overlay (IBO) and CD-SEM results. We also report the tool induced shifts (TIS) and dynamic repeatability.

[Routine oral examinations and specific after-care for removable partial dentures].

Science.gov (United States)

de Baat, C; Witter, D J; Keltjens, H M A M; Creugers, N H J

2011-01-01

Following treatment with a removable partial denture, routine oral examinations are required to stabilize the existing condition in a sustainable way and to make possible the timely treatment of anomalies which have appeared. In cases of problems assessed during a routine oral examination in relation to the removable partial dentures, maintenance, restorative and prosthetic treatment may be indicated. Maintenance treatments are indicated for small and easily retrievable alterations. In removable partial denture treatment, adequate space between prepared tooth and denture is essential. Possible prosthetic treatments of a removable partial denture are relining, rebasing, improving or renewing the maxillomandibular relation, repairment, and extension.

Diffraction-based overlay metrology for double patterning technologies

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Dasari, Prasad; Korlahalli, Rahul; Li, Jie; Smith, Nigel; Kritsun, Oleg; Volkman, Cathy

2009-03-01

The extension of optical lithography to 32nm and beyond is made possible by Double Patterning Techniques (DPT) at critical levels of the process flow. The ease of DPT implementation is hindered by increased significance of critical dimension uniformity and overlay errors. Diffraction-based overlay (DBO) has shown to be an effective metrology solution for accurate determination of the overlay errors associated with double patterning [1, 2] processes. In this paper we will report its use in litho-freeze-litho-etch (LFLE) and spacer double patterning technology (SDPT), which are pitch splitting solutions that reduce the significance of overlay errors. Since the control of overlay between various mask/level combinations is critical for fabrication, precise and accurate assessment of errors by advanced metrology techniques such as spectroscopic diffraction based overlay (DBO) and traditional image-based overlay (IBO) using advanced target designs will be reported. A comparison between DBO, IBO and CD-SEM measurements will be reported. . A discussion of TMU requirements for 32nm technology and TMU performance data of LFLE and SDPT targets by different overlay approaches will be presented.

ORAL HYGIENE OF PROSTHETIC DENTURE USER IN KODINGARENG ISLAND

OpenAIRE

NUR, NURUL KUSUMADEWI S.KG

2008-01-01

Objectives:to determine the level of oral hygiene for prosthetic denture user, especially for full-denture in Kodingareng Island. This researchincluded the distribution level of prosthetic denture user based on age and education.Methods: the method that used in this research is observational descriptive withcross sectional-studyas the research design. Variable result of the research determined in to 3, those are bad, middle, and good. Result:the highest percentage o...

Real cell overlay measurement through design based metrology

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Yoo, Gyun; Kim, Jungchan; Park, Chanha; Lee, Taehyeong; Ji, Sunkeun; Jo, Gyoyeon; Yang, Hyunjo; Yim, Donggyu; Yamamoto, Masahiro; Maruyama, Kotaro; Park, Byungjun

2014-04-01

Until recent device nodes, lithography has been struggling to improve its resolution limit. Even though next generation lithography technology is now facing various difficulties, several innovative resolution enhancement technologies, based on 193nm wavelength, were introduced and implemented to keep the trend of device scaling. Scanner makers keep developing state-of-the-art exposure system which guarantees higher productivity and meets a more aggressive overlay specification. "The scaling reduction of the overlay error has been a simple matter of the capability of exposure tools. However, it is clear that the scanner contributions may no longer be the majority component in total overlay performance. The ability to control correctable overlay components is paramount to achieve the desired performance.(2)" In a manufacturing fab, the overlay error, determined by a conventional overlay measurement: by using an overlay mark based on IBO and DBO, often does not represent the physical placement error in the cell area of a memory device. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion, caused by etching or CMP, also can be a source of the mismatch. Therefore, the requirement of a direct overlay measurement in the cell pattern gradually increases in the manufacturing field, and also in the development level. In order to overcome the mismatch between conventional overlay measurement and the real placement error of layer to layer in the cell area of a memory device, we suggest an alternative overlay measurement method utilizing by design, based metrology tool. A basic concept of this method is shown in figure1. A CD-SEM measurement of the overlay error between layer 1 and 2 could be the ideal method but it takes too long time to extract a lot of data from wafer level. An E-beam based DBM tool provides high speed to cover the whole wafer with high repeatability. It is enabled by using the design as a

Influence of denture adhesives on occlusion and disocclusion times.

Science.gov (United States)

Abdelnabi, Mohamed Hussein; Swelem, Amal Ali; Al-Dharrab, Ayman A

2016-03-01

The effectiveness of adhesives in enhancing several functional aspects of complete denture performance has been well established. The direct influence of adhesives on occlusal contact simultaneity has not yet been investigated. The purpose of this crossover clinical trial was to evaluate quantitatively the influence of adhesives on occlusal balance by recording timed occlusal contacts; namely occlusion time (OT) and disocclusion time during right (DT-right) and left (DT-left) excursions by using computerized occlusal analysis. A crossover clinical trial was adopted. Assessments were carried out while participants (n=49) wore their dentures first without then with adhesives. Computerized occlusal analysis using the T-Scan III system was conducted to perform baseline computer-guided occlusal adjustment for conventionally fabricated dentures. Retention and stability assessment using the modified Kapur index and recording of OT and DT-right and DT-left values using the T-Scan III were subsequently carried out for all dentures, first without adhesives and then after application of adhesive. All T-Scan procedures were carried out by the same clinician. Wilcoxon signed-rank test was used to analyze the Kapur index scores and occlusal parameters (α=.05). Stability and retention of conventional dentures ranged initially from good to very good. However, adhesive application resulted in significant improvement (PAdhesives significantly decreased OT and DT durations in initially well-fitting complete dentures with fairly well balanced occlusion, and further enhanced denture stability and occlusal contact simultaneity. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Evaluation of efficacy of commercial denture cleansing agents to reduce the fungal biofilm activity from heat polymerized denture acrylic resin: An in vitro study

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Mithilesh M Dhamande

2012-01-01

Full Text Available Aims: To compare and evaluate Candida removing effects of three most commonly available varieties of commercial denture cleansers from heat polymerized acrylic resins. To compare and evaluate Candida lytic effects of denture cleansers. To assess the effect of time on ability of denture cleansers in reducing Candidal biofilm. Materials and Methods: A specially designed metal mold was fabricated to obtain wax plates of uniform dimensions which were used to fabricate heat cure acrylic resin plates. A square-shaped window of dimension 15 mm and thickness of 1.5 mm was provided in metal mould to simulate thickness of denture base. All samples used in this study were prepared using this mould. Candida albicans colonies were then cultured on this acrylic resin plates by colonization assay. Yeast removing test for samples was performed using microscope and yeast lytic test was performed using photo colorimeter. Results: Denture cleanser D2 showed the highest Candida removing activity when compared with cleansers D1, D3, and control solution. Denture cleansers D2 showed increased yeast lytic ability when compared with denture cleansers D1, D3, and control solution. More time span shared a definite influence on yeast lytic ability of denture cleansers. Conclusions: The effect of cleansing agents on removal of colonized yeasts particularly fungal biofilm from acrylic resins was assessed for clinical implications. The observation indicated superior performance of cleanser D2 when compared with D1 and D3 even though they all belong to same chemical group of alkaline peroxide. The increased effectiveness may be due to presence of sodium lauryl sulphate in formula of D2.

A comparison of advanced overlay technologies

Science.gov (United States)

Dasari, Prasad; Smith, Nigel; Goelzer, Gary; Liu, Zhuan; Li, Jie; Tan, Asher; Koh, Chin Hwee

2010-03-01

The extension of optical lithography to 22nm and beyond by Double Patterning Technology is often challenged by CDU and overlay control. With reduced overlay measurement error budgets in the sub-nm range, relying on traditional Total Measurement Uncertainty (TMU) estimates alone is no longer sufficient. In this paper we will report scatterometry overlay measurements data from a set of twelve test wafers, using four different target designs. The TMU of these measurements is under 0.4nm, within the process control requirements for the 22nm node. Comparing the measurement differences between DBO targets (using empirical and model based analysis) and with image-based overlay data indicates the presence of systematic and random measurement errors that exceeds the TMU estimate.

Ecology of Candida-associated Denture Stomatitis

OpenAIRE

Budtz-Jørgensen, Ejvind

2011-01-01

Introduction of a prosthesis into the oral cavity results in profound alterations of the environmental conditions as the prosthesis and the underlying mucosa become colonized with oral microorganisms, including Candida spp. This may lead to denture stomatitis, a non-specific inflammatory reaction against microbial antigens, toxins and enzymes produced by the colonizing microorganisms. The role of Candida in the etiology of denture stomatitis is indicated by an increased number of yeasts on th...

Poor oral hygiene, wearing dentures at night, perceptions of mouth dryness and burning, and lower educational level may be related to oral malodor in denture wearers.

Science.gov (United States)

Garrett, Neal R

2010-03-01

The study sample was recruited from edentulous patients seeking new dentures at the Kirikkale University Denture Clinic, Turkey. Male (n = 56) and female (n = 49) participants were enrolled and ranged from 50 to 78 years of age (mean age 60.7 6 7.7 years). All 105 completed baseline evaluations, new denture therapy, and follow-up examination approximately 4 weeks after denture treatment completion. The study was approved by the institution's Ethics Committee. Dates for patient recruitment and conduct of the study were not provided. For the prognostic component of the study, the primary factors of interest were sociodemographic characteristics, medical conditions previously related to oral malodor, and self-reported oral hygiene habits. The primary exposure for the interventional component was oral hygiene instruction, including brushing the tongue, cleaning the denture, and not wearing the denture at night. After treatment with new dentures, participants were instructed to follow these hygiene instructions daily and were evaluated 4 weeks later. The primary outcome measure was the degree of oral malodor with the original conventional dentures and following new denture treatment and oral hygiene instruction with 4 weeks of self-administered hygiene care. Oral malodor was expressed both quantitatively as the number of parts per billion (ppb) of volatile sulfide compounds (VSCs) and as a binary measure (present/absent) based on a threshold for oral malodor of greater than 110 ppb. Significant relationships with oral malodor (level of VSCs) at baseline with the original denture were found for education (those having only primary school education were more likely to have higher VSC level, odds ratio [OR] 8.6, P = .046), self-reported oral dryness (OR 2.5, P = .037), self-reported overnight denture wear (OR 0.342 [likely a typographical error in the table; based on the 95% CI of 1.59 to 8.35, the OR is probably 3.42], P = .002), and level of bacterial plaque coverage on

Socio-Demographic and Economic Factors Affecting the Acceptance of Removable Dentures

Science.gov (United States)

Baran, İlgi; Ergün, Gülfem; Semiz, Mustafa

2007-01-01

Objectives The aim of this study was to evaluate relationships between the socio-demographic and economic factors of patients and the reasons of admission, usage periods of the two types of clinics, frequencies of denture changes, satisfaction levels and preferences of prosthetic dental treatment. Materials and Methods 510 partially and/or totally edentulous patients were studied using a questionnaire. The questionnaire consisted of questions; age, gender, education level, income status, problems with dentures, necessity for new dentures. Also asked was the place that the subjects would prefer to get their denture treatment, irrespective of their income level. In this study, Z-test was used to analyze two-sample proportions, T-test was used to determine two-sample means and Chi-square test was used to determine relationship between two classified variables. Results The number of male patients with complete dentures was more than the number of females, with an opposing trend for partial dentures. Irrespective of gender, each patient had had nearly two dentures by the time of questioning. It was also observed that the university clinics were generally preferred by patients from higher income levels with a higher educational level (x2=25.206, Pdenture treatment, regardless of cost, private practice was the preferred-choice. Conclusions With respect to dental condition and the acceptance of removable dentures, there were differences among gender, educational level and income status. PMID:19212485

Hybrid overlay metrology for high order correction by using CDSEM

Science.gov (United States)

Leray, Philippe; Halder, Sandip; Lorusso, Gian; Baudemprez, Bart; Inoue, Osamu; Okagawa, Yutaka

2016-03-01

Overlay control has become one of the most critical issues for semiconductor manufacturing. Advanced lithographic scanners use high-order corrections or correction per exposure to reduce the residual overlay. It is not enough in traditional feedback of overlay measurement by using ADI wafer because overlay error depends on other process (etching process and film stress, etc.). It needs high accuracy overlay measurement by using AEI wafer. WIS (Wafer Induced Shift) is the main issue for optical overlay, IBO (Image Based Overlay) and DBO (Diffraction Based Overlay). We design dedicated SEM overlay targets for dual damascene process of N10 by i-ArF multi-patterning. The pattern is same as device-pattern locally. Optical overlay tools select segmented pattern to reduce the WIS. However segmentation has limit, especially the via-pattern, for keeping the sensitivity and accuracy. We evaluate difference between the viapattern and relaxed pitch gratings which are similar to optical overlay target at AEI. CDSEM can estimate asymmetry property of target from image of pattern edge. CDSEM can estimate asymmetry property of target from image of pattern edge. We will compare full map of SEM overlay to full map of optical overlay for high order correction ( correctables and residual fingerprints).

Wispy Prosthesis: A Novel Method in Denture Weight Reduction.

Science.gov (United States)

Anne, Gopinadh; Budeti, Sreedevi; Anche, Sampath Kumar; Zakkula, Srujana; Atla, Jyothi; Jyothula, Ravi Rakesh Dev; Appana, Krishna Chaitanya; Peddinti, Vijaya Kumar

2016-04-01

Stability and retention of the denture becomes at stake with the increase in weight of the denture prosthesis. As a consequence, different materials and methods have been introduced to overcome these issues but denture weight reduction still remains to be a cumbersome and strenuous procedure. To introduce a novel technique for the fabrication of denture prosthesis where in the weight of the denture will not affect the retention and stability of the denture. Four groups with a sample size of 10 each, were included where in one group was control and other three were study groups. The control group samples were made completely solid and the study group samples were packed with materials like bean balls, cellulose balls and polyacrylic fibers. The weight of all the samples of each study group was measured and compared with the control group. The observations were analyzed statistically by paired t-test. It was observed that the bean balls group produced a weight reduction of 31.3%, cellulose balls group 27.4% and polyacrylic fibers group 24.5% when compared to that of the control group. This novel technique will eliminate the problems that were associated in creating hollowness and at the same time will reduce the weight of the prosthesis and among all the study groups, bean balls group were found to reduce maximum weight of the prosthesis.

Tensile and shear bond strength of hard and soft denture relining materials to the conventional heat cured acrylic denture base resin: An In-vitro study.

Science.gov (United States)

Lau, Mayank; Amarnath, G S; Muddugangadhar, B C; Swetha, M U; Das, Kopal Anshuraj Ashok Kumar

2014-04-01

The condition of the denture bearing tissues may be adversely affected by high stress concentration during function. Chairside Denture (Hard and Soft) reliners are used to distribute forces applied to soft tissues during function. Tensile and shear bond strength has been shown to be dependent on their chemical composition. A weak bond could harbor bacteria, promote staining and delamination of the lining material. To investigate tensile and shear bond strength of 4 different commercially available denture relining materials to conventional heat cured acrylic denture base resin. 4 mm sections in the middle of 160 Acrylic cylindrical specimens (20 mm x 8 mm) were removed, packed with test materials (Mollosil, G C Reline Soft, G C Reline Hard (Kooliner) and Ufi Gel Hard and polymerized. Specimens were divided into 8 groups of 20 each. Tensile and shear bond strength to the conventional heat cured acrylic denture base resin were examined by Instron Universal Tensile Testing Machine using the equation F=N/A (F-maximum force exerted on the specimen (Newton) and A-bonding area= 50.24 mm2). One-way ANOVA was used for multiple group comparisons followed by Bonferroni Test and Hsu's MCB for multiple pairwise comparisons to asses any significant differences between the groups. The highest mean Tensile bond strength value was obtained for Ufi Gel Hard (6.49+0.08 MPa) and lowest for G C Reline Soft (0.52+0.01 MPa). The highest mean Shear bond strength value was obtained for Ufi Gel Hard (16.19+0.1 MPa) and lowest for Mollosil (0.59+0.05 MPa). The Benferroni test showed a significant difference in the mean tensile bond strength and the mean shear bond strength when the two denture soft liners were compared as well as when the two denture hard liners were compared. Hsu's MCB implied that Ufi gel hard is better than its other closest competitors. The Tensile and Shear bond strength values of denture soft reliners were significantly lower than denture hard reliners. How to cite the

Esthetic Rehabilitation with a Cast Partial Denture

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Suraksha Shrestha

2017-01-01

Full Text Available Removable partial denture is a treatment option where fixed prosthesis is not indicated. Due to its esthetic problems in the anterior region various modifications have been designed for its fabrication. This article describes an esthetic alternative using a round rest distal depression clasp for maxillary anterior teeth abutment while restoring the missing teeth with a cast partial denture.

The knowledge and attitude of general dentists toward denture adhesives in Tehran

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Fakhri Hamidreza

2009-01-01

Full Text Available Background: The purpose of this study was to generate discussion and communication among a group of general dentists in Tehran on their viewpoints regarding denture adhesives. Have they accepted denture adhesive as a material to enhance denture retention, stability and function? Materials and Methods: In the summer of 2007, a questionnaire was mailed to 300 general dentists who were assigned with a random systematic sampling method from general dentists in Tehran. The questions were arranged in two parts of evaluating knowledge and attitude. In evaluation of knowledge, dentists were classified into groups of good, moderate, weak and lack of knowledge. In evaluation of attitude, dentists were classified into positive, moderate and negative groups. (Evaluating attitude was carried out in good and moderate groups of knowledge. Results: The study showed that 14%, 32% and 37% of the general dentists had respectively good, moderate and weak knowledge toward denture adhesive while 16.3% had no knowledge about this material. In evaluation of attitude through dentists with positive and moderate knowledge toward denture adhesive, 9.3%, 71.3% and 19.4% had respectively positive, moderate and negative attitude toward denture adhesive. The χ2 test showed a significant statistical relation between situation of knowledge and experiences of dentists. Discussion: This study demonstrated that the rate of knowledge of these 300 general dentists in Tehran towards denture adhesives has not been in a good situation. It is believed that denture adhesive be able to enhance the fitness of a denture and provide psychological relief to the patient. Dentists agreed that education, not only for practitioners but also for patients, would raise the advantageous features and reduce the misuse of denture adhesive. Education of the topic "Denture adhesive" should be more concerned in dental universities.

Mechanical properties of denture base resins: An evaluation

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Pooran Chand

2011-01-01

Conclusion: The heat cure denture base material D (Trevalon "HI" was the strongest and C (Trevalon was the weakest among all materials used in this study. The study showed that the deflection of various denture base resins (A to D increases proportionately with the increase in load.

Diffraction-based overlay for spacer patterning and double patterning technology

Science.gov (United States)

Lee, Byoung Hoon; Park, JeongSu; Lee, Jongsu; Park, Sarohan; Lim, ChangMoon; Yim, Dong-Gyu; Park, Sungki; Ryu, Chan-Ho; Morgan, Stephen; van de Schaar, Maurits; Fuchs, Andreas; Bhattacharyya, Kaustuve

2011-03-01

Overlay performance will be increasingly important for Spacer Patterning Technology (SPT) and Double Patterning Technology (DPT) as various Resolution Enhancement Techniques are employed to extend the resolution limits of lithography. Continuous shrinkage of devices makes overlay accuracy one of the most critical issues while overlay performance is completely dependent on exposure tool. Image Based Overlay (IBO) has been used as the mainstream metrology for overlay by the main memory IC companies, but IBO is not suitable for some critical layers due to the poor Tool Induced Shift (TIS) values. Hence new overlay metrology is required to improve the overlay measurement accuracy. Diffraction Based Overlay (DBO) is regarded to be an alternative metrology to IBO for more accurate measurements and reduction of reading errors. Good overlay performances of DBO have been reported in many articles. However applying DBO for SPT and DPT layers poses extra challenges for target design. New vernier designs are considered for different DPT and SPT schemes to meet overlay target in DBO system. In this paper, we optimize the design of the DBO target and the performance of DBO to meet the overlay specification of sub-3x nm devices which are using SPT and DPT processes. We show that the appropriate vernier design yields excellent overlay performance in residual and TIS. The paper also demonstrated the effects of vernier structure on overlay accuracy from SEM analysis.

Candida colonization on the denture of diabetic and non-diabetic patients

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Mohammad Hossein Lotfi-Kamran

2009-01-01

Full Text Available Background: Oral candidiasis is a common opportunistic infection in diabetic patients. Presence of denture in the oral cavity of diabetic patients can promote Candida colonization and results in the higher incidence of oral and systemic candidiasis. The general purpose of the present study was to evaluate and compare Candida colonization in denture of diabetic patients and non-diabetic control group. Methods: In current case-control study, samples for mycological examinations were collected from the palatal impression surface of maxillary dentures from 92 edentulous patients including 46 dia-betic and 46 non-diabetic denture wearers. All samples were cultured directly on sabouraud agar me-dium and isolated colonies were counted and identified based on specific tests. Data were statistically analyzed using Mann-Whitney and Spearman correlation tests. Results: The higher density of isolated colonies was seen in diabetic group in compare with control group (P = 0.0001. There was a statistically significant correlation between the blood glucose level (P = 0.0001 and the duration of denture usage (P = 0.022 with the colonization of Candida on den-ture of diabetic patients. C. albicans was the most common isolated Candida species in both groups, though diabetic patients with dentures had more non-albicans Candida isolated from their dentures compared to non-diabetic patients. Conclusions: Mycological findings from the present study revealed that diabetes mellitus can in-crease colonization of Candida in denture and mouth. By elimination of local and systemic factors in diabetic patients and improving their oral health care, Candida colonization and the risk of oral and systemic candidiasis will be decreased.

Color stability of different denture teeth materials: an in vitro study.

Science.gov (United States)

Mutlu-Sagesen, L; Ergün, G; Ozkan, Y; Bek, B

2001-09-01

The aim of this in vitro study was to compare the color stability of commercially available porcelain, reinforced acrylic, and conventional acrylic denture teeth materials used in removable prostheses. Two brands of porcelain (Unilux-Enta Lactona-Holland and Vivoperl-Ivoclar-Liechtenstein), 2 brands of reinforced acrylic (Optodent-Bayer-Germany and Ivolek-Ivoclar-Liechtenstein), and 2 brands of conventional acrylic (Isodent-Güney Diş Deposu-Turkey and Samed-Turkey), were made, for a total of 6 different denture teeth groups. Denture teeth were subjected to 3 staining solutions (filtered coffee, tea, and cola) and distilled water. From each group of denture teeth, 4 sets of maxillary anterior denture teeth were immersed in each of the 4 solutions. The color values of denture teeth were measured colorimetrically with the Gardner XL 20 Tristimulus Colorimeter (Gardner Lab. Inc., Bethesda, Maryland, USA). Color changes were characterized in the CIEL*a*b* color space. Color change values were determined after 1 day, 1 week, 2 weeks, and 4 weeks. The color difference values were calculated and then evaluated by two-way ANOVA statistically. The filtered coffee solution was found to be more chromogenic than the other 2 staining solutions, while porcelain denture teeth materials were more color stable. Assuming the color change of deltaE* < 1.0 as a discernible limit and deltaE* = 3.3 as an acceptable value, the filtered coffee, tea, and cola had slight staining effects on all 6 groups of denture teeth.

High-throughput electrical characterization for robust overlay lithography control

Science.gov (United States)

Devender, Devender; Shen, Xumin; Duggan, Mark; Singh, Sunil; Rullan, Jonathan; Choo, Jae; Mehta, Sohan; Tang, Teck Jung; Reidy, Sean; Holt, Jonathan; Kim, Hyung Woo; Fox, Robert; Sohn, D. K.

2017-03-01

Realizing sensitive, high throughput and robust overlay measurement is a challenge in current 14nm and advanced upcoming nodes with transition to 300mm and upcoming 450mm semiconductor manufacturing, where slight deviation in overlay has significant impact on reliability and yield1). Exponentially increasing number of critical masks in multi-patterning lithoetch, litho-etch (LELE) and subsequent LELELE semiconductor processes require even tighter overlay specification2). Here, we discuss limitations of current image- and diffraction- based overlay measurement techniques to meet these stringent processing requirements due to sensitivity, throughput and low contrast3). We demonstrate a new electrical measurement based technique where resistance is measured for a macro with intentional misalignment between two layers. Overlay is quantified by a parabolic fitting model to resistance where minima and inflection points are extracted to characterize overlay control and process window, respectively. Analyses using transmission electron microscopy show good correlation between actual overlay performance and overlay obtained from fitting. Additionally, excellent correlation of overlay from electrical measurements to existing image- and diffraction- based techniques is found. We also discuss challenges of integrating electrical measurement based approach in semiconductor manufacturing from Back End of Line (BEOL) perspective. Our findings open up a new pathway for accessing simultaneous overlay as well as process window and margins from a robust, high throughput and electrical measurement approach.

New low-viscosity overlay medium for viral plaque assays

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Garten Wolfgang

2006-08-01

Full Text Available Abstract Background Plaque assays in cell culture monolayers under solid or semisolid overlay media are commonly used for quantification of viruses and antiviral substances. To overcome the pitfalls of known overlays, we tested suspensions of microcrystalline cellulose Avicel RC/CL™ as overlay media in the plaque and plaque-inhibition assay of influenza viruses. Results Significantly larger plaques were formed under Avicel-containing media, as compared to agar and methylcellulose (MC overlay media. The plaque size increased with decreasing Avicel concentration, but even very diluted Avicel overlays (0.3% ensured formation of localized plaques. Due to their low viscosity, Avicel overlays were easier to use than methylcellulose overlays, especially in the 96-well culture plates. Furthermore, Avicel overlay could be applied without prior removal of the virus inoculum thus facilitating the assay and reducing chances of cross-contamination. Using neuraminidase inhibitor oseltamivir carboxylate, we demonstrated applicability of the Avicel-based plaque reduction assay for testing of antiviral substances. Conclusion Plaque assay under Avicel-containing overlay media is easier, faster and more sensitive than assays under agar- and methylcellulose overlays. The assay can be readily performed in a 96-well plate format and seems particularly suitable for high-throughput virus titrations, serological studies and experiments on viral drug sensitivity. It may also facilitate work with highly pathogenic agents performed under hampered conditions of bio-safety labs.

Investigating oral health-related quality of life and self-perceived satisfaction with partial dentures.

Science.gov (United States)

Abuzar, Menaka A; Kahwagi, Esperance; Yamakawa, Takeshi

2012-05-01

To investigate the prevalence and severity of oral health-related quality of life in patients treated with removable partial dentures at a publicly-funded dental hospital. The association between patients' demographic profiles, denture-related, variables and oral health-related quality of life was also investigated. A questionnaire was designed to investigate the use and satisfaction of removable partial dentures, and oral health-related quality of life of removable partial denture wearers using the Oral Health Impact Profile-14. The questionnaire was administered to 740 randomly-selected patients who received removable partial dentures during 2005-2008. The response rate was 31.35%. Non-parametric tests and a logistic regression model were used to analyze the association between denture-related variables and oral health-related quality of life. A question on symptoms unrelated to dentures was also analyzed. The Oral Health Impact Profile-14 prevalence calculated was 43.1%. The removable partial denture experience and frequency of use was inversely associated with Oral Health Impact Profile-14 scores. Metal-based removable partial dentures were associated with lower Oral Health Impact Profile prevalence and severity scores. No significant association was found between demographic profile, circumstance for provision of removable partial dentures and Oral Health Impact Profile-14 score. The participants of this study indicated that perceived denture performance, removable partial dentures material, experience, and frequency of use are associated with oral health-related quality of life. © 2012 Blackwell Publishing Asia Pty Ltd.

Impact of removable dentures on oral health-related quality of life among elderly adults in Taiwan.

Science.gov (United States)

Yen, Yea-Yin; Lee, Huey-Er; Wu, Yi-Min; Lan, Shou-Jen; Wang, Wen-Chen; Du, Je-Kang; Huang, Shun-Te; Hsu, Kun-Jung

2015-01-05

Although the use of removable dentures can improve oral function and esthetics for elderly people, compared to those who do not wear removable dentures, those wearing removable dentures could have worse oral health related-quality of life (OHRQoL). Additional information is required to assess which factors related to denture wearing influence the OHRQoL of elderly individuals. The purpose of this study is to evaluate the association between denture wearing and OHRQoL in a sample of elderly individuals in Taiwan. The study population included 277 elderly people wearing removable dentures (mean age = 76.0 years). Using face-to-face interviews, we collected data on the participants' socio-demographic characteristics, dental care service usage (regular dental checkups, treatment during toothache, dental visits in the last year), and factors related to denture wearing (perceived oral pain, perceived loose denture, perceived oral ulcer, perceived halitosis, perceived dry mouth, and perceived total denture satisfaction scores). OHRQoL was measured using the Taiwanese version of the Geriatric Oral Health Assessment Index (GOHAI-T). The location and number of remaining natural teeth and the type of denture were also recorded. Hierarchical multiple regression analysis was performed using GOHAI-T scores as the dependent variable. All the predictors together accounted for 50% of the variance in GOHAI-T scores. Further, education level, number of natural teeth, denture status, perceived loose denture, perceived oral ulcer, and perceived total denture satisfaction scores had statistically significant influences on OHRQoL. When compared with other variables, factors related to denture wearing, especially perceived total denture satisfaction scores, had the greatest impact on GOHAI-T scores. Of the factors analyzed in this study, denture satisfaction was the strongest predictor of OHRQoL. This suggests that denture satisfaction is useful for assessing the effect of denture

The effect of various factors on the masticatory performance of removable denture wearer

Science.gov (United States)

Pratama, S.; Koesmaningati, H.; Kusdhany, L. S.

2017-08-01

An individual’s masticatory performance concerns his/her ability to break down food in order to facilitate digestion, and it therefore plays an important role in nutrition. Removable dentures are used to rehabilitate a loss of teeth, which could jeopardize masticatory performance. Further, there exist various other factors that can affect masticatory performance. The objective of this research is to analyze the relationship between various factors and masticatory performance. Thirty-four removable denture wearers (full dentures, single complete dentures, or partial dentures) participated in a cross-sectional study of masticatory performance using color-changeable chewing gum (Masticatory Performance Evaluating Gum Xylitol®). The volume of saliva was evaluated using measuring cups, while the residual ridge heights were measured using a modified mouth mirror no. 3 with metric measurements. The residual ridge height and removable-denture-wearing experience exhibited a significant relationship with masticatory performance. However, age, gender, saliva volume, denture type, and the number and location of the missing teeth did not have a statistically significant association with masticatory performance. The residual ridge height influences the masticatory performance of removable denture wearers, since the greater the ridge height, the better the performance. The experience of using dentures also has a statistically significant influence on masticatory performance.

SEM based overlay measurement between resist and buried patterns

Science.gov (United States)

Inoue, Osamu; Okagawa, Yutaka; Hasumi, Kazuhisa; Shao, Chuanyu; Leray, Philippe; Lorusso, Gian; Baudemprez, Bart

2016-03-01

With the continuous shrink in pattern size and increased density, overlay control has become one of the most critical issues in semiconductor manufacturing. Recently, SEM based overlay of AEI (After Etch Inspection) wafer has been used for reference and optimization of optical overlay (both Image Based Overlay (IBO) and Diffraction Based Overlay (DBO)). Overlay measurement at AEI stage contributes monitor and forecast the yield after formation by etch and calibrate optical measurement tools. however those overlay value seems difficult directly for feedback to a scanner. Therefore, there is a clear need to have SEM based overlay measurements of ADI (After Develop Inspection) wafers in order to serve as reference for optical overlay and make necessary corrections before wafers go to etch. Furthermore, to make the corrections as accurate as possible, actual device like feature dimensions need to be measured post ADI. This device size measurement is very unique feature of CDSEM , which can be measured with smaller area. This is currently possible only with the CD-SEM. This device size measurement is very unique feature of CD-SEM , which can be measured with smaller area. In this study, we assess SEM based overlay measurement of ADI and AEI wafer by using a sample from an N10 process flow. First, we demonstrate SEM based overlay performance at AEI by using dual damascene process for Via 0 (V0) and metal 1 (M1) layer. We also discuss the overlay measurements between litho-etch-litho stages of a triple patterned M1 layer and double pattern V0. Second, to illustrate the complexities in image acquisition and measurement we will measure overlay between M1B resist and buried M1A-Hard mask trench. Finally, we will show how high accelerating voltage can detect buried pattern information by BSE (Back Scattering Electron). In this paper we discuss the merits of this method versus standard optical metrology based corrections.

Factors influencing patients’ satisfaction with complete dentures: a qualitative study.

OpenAIRE

Silva, Jessica de Cassia Motta; Departamento de Odontologia – Univ de Taubaté – Taubaté – SP – Brazil.; dos Santos, Jarbas Francisco Fernandes; Departamento de Odontologia – Univ de Taubaté – Taubaté – SP – Brazil.; Marchini, Leonardo; College of Dentistry – University of Iowa – Iowa City – IA – USA.

2014-01-01

Objective: The treatment most used worldwide for edentulism is conventional complete dentures, and the most important factor for the success of denture treatment seems to be patient satisfaction. The present study aims to use a qualitative approach to investigate factors that were previously associated with patient satisfaction with dentures by quantitative techniques (correlational studies). Material and methods: Twenty patients (12 women and 8 men, age 59-87) participated in open and semi-s...

Image-based overlay measurement using subsurface ultrasonic resonance force microscopy

Science.gov (United States)

Tamer, M. S.; van der Lans, M. J.; Sadeghian, H.

2018-03-01

Image Based Overlay (IBO) measurement is one of the most common techniques used in Integrated Circuit (IC) manufacturing to extract the overlay error values. The overlay error is measured using dedicated overlay targets which are optimized to increase the accuracy and the resolution, but these features are much larger than the IC feature size. IBO measurements are realized on the dedicated targets instead of product features, because the current overlay metrology solutions, mainly based on optics, cannot provide sufficient resolution on product features. However, considering the fact that the overlay error tolerance is approaching 2 nm, the overlay error measurement on product features becomes a need for the industry. For sub-nanometer resolution metrology, Scanning Probe Microscopy (SPM) is widely used, though at the cost of very low throughput. The semiconductor industry is interested in non-destructive imaging of buried structures under one or more layers for the application of overlay and wafer alignment, specifically through optically opaque media. Recently an SPM technique has been developed for imaging subsurface features which can be potentially considered as a solution for overlay metrology. In this paper we present the use of Subsurface Ultrasonic Resonance Force Microscopy (SSURFM) used for IBO measurement. We used SSURFM for imaging the most commonly used overlay targets on a silicon substrate and photoresist. As a proof of concept we have imaged surface and subsurface structures simultaneously. The surface and subsurface features of the overlay targets are fabricated with programmed overlay errors of +/-40 nm, +/-20 nm, and 0 nm. The top layer thickness changes between 30 nm and 80 nm. Using SSURFM the surface and subsurface features were successfully imaged and the overlay errors were extracted, via a rudimentary image processing algorithm. The measurement results are in agreement with the nominal values of the programmed overlay errors.

Scatterometry or imaging overlay: a comparative study

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Hsu, Simon C. C.; Pai, Yuan Chi; Chen, Charlie; Yu, Chun Chi; Hsing, Henry; Wu, Hsing-Chien; Kuo, Kelly T. L.; Amir, Nuriel

2015-03-01

Most fabrication facilities today use imaging overlay measurement methods, as it has been the industry's reliable workhorse for decades. In the last few years, third-generation Scatterometry Overlay (SCOL™) or Diffraction Based Overlay (DBO-1) technology was developed, along another DBO technology (DBO-2). This development led to the question of where the DBO technology should be implemented for overlay measurements. Scatterometry has been adopted for high volume production in only few cases, always with imaging as a backup, but scatterometry overlay is considered by many as the technology of the future. In this paper we compare imaging overlay and DBO technologies by means of measurements and simulations. We outline issues and sensitivities for both technologies, providing guidelines for the best implementation of each. For several of the presented cases, data from two different DBO technologies are compared as well, the first with Pupil data access (DBO-1) and the other without pupil data access (DBO-2). Key indicators of overlay measurement quality include: layer coverage, accuracy, TMU, process robustness and robustness to process changes. Measurement data from real cases across the industry are compared and the conclusions are also backed by simulations. Accuracy is benchmarked with reference OVL, and self-consistency, showing good results for Imaging and DBO-1 technology. Process sensitivity and metrology robustness are mostly simulated with MTD (Metrology Target Designer) comparing the same process variations for both technologies. The experimental data presented in this study was done on ten advanced node layers and three production node layers, for all phases of the IC fabrication process (FEOL, MEOL and BEOL). The metrology tool used for most of the study is KLA-Tencor's Archer 500LCM system (scatterometry-based and imaging-based measurement technologies on the same tool) another type of tool is used for DBO-2 measurements. Finally, we conclude that

Functional Impressions in Complete Denture and Overdenture Treatment

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Hrvoje Kršek

2015-01-01

Full Text Available Tooth loss can cause loss of occlusal, masticatory, esthetic, physiognomic, phonetic and psychosocial function of patients. The most frequently used treatment method of completely edentulous patients and patients with a small number of remaining teeth are complete dentures or overdentures. One of the most important clinical and laboratory procedures in their fabrication is functional impression taking. The aim of this paper was to present procedures of taking functional impressions in fabrication of complete dentures and overdentures, using standardized techniques and materials. An accurate functional impression together with other correctly performed clinical and laboratory procedures ensure good retention and stability of dentures, which is a precondition for restoring patients’ lost functions.

Isolation of Candida species from the oral cavity and fingertips of complete denture wearers.

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Nagaral, Suresh; Desai, Raviraj G; Kamble, Vikas; Patil, Anand Kumar G

2014-11-01

Wearing a dental prosthesis is known to increase oral candidal colonization and predispose the wearer to oral candidosis. Denture wearers frequently use fingers to take the prosthesis out of their mouth. Oral Candida, if present may contaminate wearer's finger. The objective of this study was to investigate the simultaneous candidal colonization of oral cavity and fingertips of complete denture wearers. A total of 25 apparently healthy male subjects who had worn complete dentures for at least 1 year were selected. Information about each patient's denture age, denture hygiene, handling, and wearing habits, and hand washing habits after denture handling were be obtained. Intraoral examination of all the patients was done. For microbiological examination samples were collected from the fingertip and oral rinse of each patient. Candida species were identified with use of germ tube test and commercially available yeast identification system. Data was statistically analyzed. Significance was set at p < 0.05. It was found that frequency of hand washing, denture handling and denture stomatitis with respect to fingertip candidal isolation was not statistically significant. But poor denture hygiene and denture stomatitis with respect to oral candidal colonization was statistically significant. Denture wearers with oral Candida had a higher prevalence of Candida contamination on their fingers. Patients with removable prostheses should be informed about the importance of proper prosthesis and personal hygiene and the possibility of microbial contamination of the hands and other parts of the body.

Effect of denture cleaning on abrasion resistance and surface topography of polymerized CAD CAM acrylic resin denture base.

Science.gov (United States)

Shinawi, Lana Ahmed

2017-05-01

The application of computer-aided design computer-aided manufacturing (CAD CAM) technology in the fabrication of complete dentures, offers numerous advantages as it provides optimum fit and eliminates polymerization shrinkage of the acrylic base. Additionally, the porosity and surface roughness of CAD CAM resins is less compared to conventionally processed resins which leads to a decrease in the adhesion of bacteria on the denture base, which is associated with many conditions including halitosis and aspiration pneumonia in elderly denture wearers. To evaluate the influence of tooth brushing with dentifrices on CAD CAM resin blocks in terms of abrasion resistance, surface roughness and scanning electron photomicrography. This experimental study was carried out at the Faculty of Dentistry of King Abdulaziz University during 2016. A total of 40 rectangular shaped polymerized CAD CAM resin samples were subjected to 40.000 and 60.000 brushing strokes under a 200-gram vertical load simulating three years of tooth brushing strokes using commercially available denture cleaning dentifrice. Data were analyzed by SPSS version 20, using descriptive statistics and ANOVA. ANOVA test revealed a statistical significant weight loss of CAD CAM acrylic resin denture base specimens following 40.000 and 60.000 brushing strokes as well as a statistical significant change (p=0.0.5) in the surface roughness following brushing. The CAD CAM resin samples SEM baseline imaging revealed a relatively smooth homogenous surface, but following 40,000 and 60,000 brushing strokes, imaging displayed the presence of small scratches on the surface. CAD CAM resin displayed a homogenous surface initially with low surface roughness that was significantly affected following simulating three years of manual brushing, but despite the significant weight loss, the findings are within the clinically acceptable limits.

Masticatory performance of complete denture wearers after using two adhesives: a crossover randomized clinical trial.

Science.gov (United States)

de Oliveira Junior, Norberto Martins; Rodriguez, Larissa Santana; Mendoza Marin, Danny Omar; Paleari, André Gustavo; Pero, Ana Carolina; Compagnoni, Marco Antonio

2014-11-01

Masticatory performance analysis of conventional complete denture wearers who use denture adhesives is scarce in the dental literature. The purpose of this study was to assess the effect of the use of 2 denture adhesives on the masticatory performance of conventional complete denture wearers by means of a crossover study. Forty individuals who were edentulous received new maxillary and mandibular complete dentures, and, after an adaptation period, were submitted to masticatory performance analysis without denture adhesive (control). The participants were randomly divided and assigned to 2 protocols: protocol 1, denture adhesive 1 (Ultra Corega cream tasteless) use during the first 15 days, followed by no use of denture adhesive over the next 15 days (washout), and then use of denture adhesive 2 (Ultra Corega powder tasteless) for 15 days; protocol 2, denture adhesive 2 (Ultra Corega powder tasteless) use during the first 15 days, followed by no use of denture adhesive during the next 15 days (washout), and then use of denture adhesive 1 (Ultra Corega cream tasteless) for 15 days. The masticatory performance was assessed immediately after the use of denture adhesive by means of the sieve method, in which participants were instructed to deliberately chew 5 almonds for 20 chewing strokes. Masticatory performance was calculated by the weight of comminuted material that passed through the sieves. Data were analyzed by a 1-way ANOVA for paired samples and the multiple comparison of means by using the Bonferroni test (α=.05). A significant increase in masticatory performance was noted after using the Ultra Corega cream (mean, 32.6%) and Ultra Corega powder (mean, 31.2%) when compared with the control group (mean, 19.8%) (Padhesives evaluated. The use of denture adhesive improved the masticatory performance of conventional complete denture wearers. No difference was found in masticatory performance with the use of cream or powder denture adhesive. Copyright © 2014

Leaching from denture base materials in vitro

Energy Technology Data Exchange (ETDEWEB)

Lygre, H.; Solheim, E.; Gjerdet, N.R. [School of Medicine, Univ. of Bergen (Norway)

1995-04-01

Specimens made from denture base materials were leached in Ringer Solution and in ethanol. The specimens comprised a heat-cured product processed in two different ways and two cold-cured materials. The organic compounds leaching from the specimens to the solutions were separated, identified, and quantified by a combined gas-chromatography and gas-chromatography/mass-spectrometry technique. Additives and degradation products, possibly made by free radical reactions, were released from the denture base materials. In Ringer solution only phthalates could be quantified. In ethanol solvent, biphenyl, dibutyl phthalate, dicyclohexyl phthalate, phenyl benzoate, and phenyl salicylate were quantified. In addition, copper was found in the ethanol solvent from one of the denture base materials. The amount of leachable organic compounds varies among different materials. Processing temperature influences the initial amount of leachable compounds. 36 refs., 7 figs., 1 tab.

Development of an Overlay Design Procedure for Composite Pavements

Science.gov (United States)

2017-09-01

The composite overlay design procedure currently used by ODOT sometimes produces very large overlay thicknesses that are deemed structurally unnecessary, especially for composite pavements already with thick asphalt overlays. This study was initiated...

A Randomised Controlled Trial of complete denture impression materials

Science.gov (United States)

Hyde, T.P.; Craddock, H.L.; Gray, J.C.; Pavitt, S.H.; Hulme, C.; Godfrey, M.; Fernandez, C.; Navarro-Coy, N.; Dillon, S.; Wright, J.; Brown, S.; Dukanovic, G.; Brunton, P.A.

2014-01-01

Objectives There is continuing demand for non-implant prosthodontic treatment and yet there is a paucity of high quality Randomised Controlled Trial (RCT) evidence for best practice. The aim of this research was to provide evidence for best practice in prosthodontic impressions by comparing two impression materials in a double-blind, randomised, crossover, controlled, clinical trial. Methods Eighty-five patients were recruited, using published eligibility criteria, to the trial at Leeds Dental Institute, UK. Each patient received two sets of dentures; made using either alginate or silicone impressions. Randomisations determined the order of assessment and order of impressions. The primary outcome was patient blinded preference for unadjusted dentures. Secondary outcomes were patient preference for the adjusted dentures, rating of comfort, stability and chewing efficiency, experience of each impression, and an OHIP-EDENT questionnaire. Results Seventy-eight (91.8%) patients completed the primary assessment. 53(67.9%) patients preferred dentures made from silicone impressions while 14(17.9%) preferred alginate impressions. 4(5.1%) patients found both dentures equally satisfactory and 7 (9.0%) found both equally unsatisfactory. There was a 50% difference in preference rates (in favour of silicone) (95%CI 32.7–67.3%, p alginate as their material of choice for secondary impressions for complete dentures. Trial Registration: ISRCTN 01528038.

 This article forms part of a project for which the author (TPH) won the Senior Clinical Unilever Hatton Award of the International Assocation for Dental Research, Capetown, South Africa, June 2014. PMID:24995473

BASIC overlay for CAMAC data and command handling

Energy Technology Data Exchange (ETDEWEB)

Ciftcioglu, O [Istanbul Technical Univ. (Turkey). Inst. for Nuclear Energy

1979-11-15

A BASIC overlay has been developed for the BASIC language run in the PDP-11 series of computers. The overlay has particularly been wirtten for a dedicated Camac Crate Controller DC-011 from Ortec. By means of the overlay, any command comprising C, N, A, F information can easily be issued by the host system to communicate with the peripherals connected to the CAMAC system, through the CAMAC interface. The overlay is particularly useful for rather slow control systems and data handling between two different operating systems with incompatible formats for the data files having the CAMAC system as a mutual system component controllable by each of the operating systems individually. The overlay can easily be modified to be used for a Standard controller (type A-1) or any other type of dedicated controller.

Overlay welding of FeCrAl alloys

OpenAIRE

Rashid, Lezan

2016-01-01

In this master thesis different overlay welding methods suitable for boiler application has been investigated. The purpose of this project is to define advantages and disadvantages for each overlay welding methods and suggest some evaluation criteria on some commercial and experimental alloys aimed for overlay welding material. Many components in a boiler are made of low alloy steel and the atmosphere in the furnace region can be very complex; therefore many different types of corrosion can o...

Going Beyond the Conventional Approach - Liquid Supported Denture: A Case Report

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Dipti S Shah

2013-01-01

Full Text Available Background: The concept of conditioning oral mucosa has gained momentum over the last few years. Different tissue conditioning materials and soft liners have been used for this purpose. But the limitations of these materials has led to the introduction of liquid-supported dentures, which is a newer alternative to conventional complete denture prosthesis in cases with inflamed tissues, atrophic and severely resorbed edentulous ridges. Liquid supported Denture consists of a base which is covered with a preshaped close fitting flexible foil containing a thin film of high viscosity liquid which cushions the underlying tissues. This case report describes fabrication of liquid-supported dentures for patients with compromised tissues.

Hybrid approach to fabrication of hollow internally weighted mandibular denture: A case report

OpenAIRE

Hazari, Puja; Mishra, Sunil Kumar

2015-01-01

Preservation of ridge dimensions is critical for denture success. For long the concept of an internally weighted denture, which suggested that gravity and the additional weight to the mandibular complete denture aids in prosthetic retention is widely accepted. However, excessive weight and pressure can accelerate bone resorption. Here, we describe a unique modification of internally weighted metal denture base for the resorbed mandibular ridge with an incorporated additional hollow section ov...

Oral health-related quality of life of edentulous patients after complete dentures relining

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Krunić Nebojša

2015-01-01

Full Text Available Background/Aim. Tooth loss affects oral health-related life quality. More than a third of edentulous patients are not fully satisfied with their complete dentures and mainly complain of insufficient stability, retention, and pain during mastication. Solving the problem may include relining by materials that are based on silicone or acrylic. The aim of this study was to determine the level of patients’ satisfaction before and after relining upper dentures with soft and rigid liners. Methods. The patients (n = 24 were divided into two study groups. Maxillary denture relining of the first group of patients was performed with hard acrylic based resins while in the second group of patients complete denture was relined with a silicone-based soft liner. They were asked the questions from the specifically adapted the Oral Health Impact Profile Questionnaire for edentulous patients before and three months after relining dentures. Results. After relining the patients showed a higher degree of satisfaction with their dentures in all the tested domains (masticatory function, psychological discomfort, social disability and retention and hygiene. The patients with soft denture relines were more satisfied. Conclusion. Relining of maxillary complete dentures significantly positively impacts the quality of life of patients in all the tested domains (masticatory function, psychological discomfort, social disability, pain and oral hygiene. Better results were achieved using a silicone-based soft liner, which recommends it as the material of choice for relining dentures.

Removable partial dentures: use of rapid prototyping.

Science.gov (United States)

Lima, Julia Magalhaes Costa; Anami, Lilian Costa; Araujo, Rodrigo Maximo; Pavanelli, Carlos A

2014-10-01

The CAD/CAM technology associated with rapid prototyping (RP) is already widely used in the fabrication of all-ceramic fixed prostheses and in the biomedical area; however, the use of this technology for the manufacture of metal frames for removable dentures is new. This work reports the results of a literature review conducted on the use of CAD/CAM and RP in the manufacture of removable partial dentures. © 2014 by the American College of Prosthodontists.

Comparison of digital surface displacements of maxillary dentures based on noninvasive anatomic landmarks.

Science.gov (United States)

Norvell, Nicholas G; Korioth, Tom V; Cagna, David R; Versluis, Antheunis

2018-02-08

Artificial markers called fiducials are commonly used to orient digitized surfaces for analysis. However, when these markers are tangible and placed in the region of interest, they may alter surface topography and influence data analysis. The purpose of this in vitro study was to apply a modified digital surface fitting method based on anatomic landmarks to evaluate denture accuracy and to use 2 different denture processing techniques to evaluate the method. The goal was to noninvasively measure and describe any surface differences in denture processing techniques at the intaglio and denture tooth levels. Twenty standardized maxillary complete dentures were waxed on standardized edentulous casts and processed by using acrylic resin compression (COM, n=10) and injection molding (INJ, n=10) methods. Digital scans were recorded of the anatomic surface of the cast, the intaglio and cameo surfaces of the acrylic resin dentures, and the cameo surface of the wax dentures. Three anatomic fiducials were identified on denture intaglio and cast scans and 4 on the cameo surfaces of waxed and acrylic resin denture scans. These fiducials were then used to digitally align the anatomic with the processed intaglio surfaces and the waxed with the processed cameo surfaces. Surface displacements were compared among processed dentures expressed at specific points (9 tissue landmarks and 8 tooth landmarks). The accuracy of surface displacements was assessed by changes in the number and location of anatomic fiducials. The scanning precision and the intraobserver repeatability in the selection of dental landmarks were also determined. For each landmark, the spatial (x, y, and z) mean differences between the 2 processing techniques were calculated for the intaglio and the cameo surfaces and presented on each orthogonal plane. Statistical nonparametric comparison of these means was analyzed with the Mann-Whitney U test (α=.05). Benjamini-Hochberg corrections for multiple comparisons were

Alveolar ridge rehabilitation to increase full denture retention and stability

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Mefina Kuntjoro

2010-12-01

Full Text Available Background: Atrophic mandibular alveolar ridge generally complicates prostetic restoration expecially full denture. Low residual alveolar ridge and basal seat can cause unstable denture, permanent ulcer, pain, neuralgia, and mastication difficulty. Pre-proshetic surgery is needed to improve denture retention and stability. Augmentation is a major surgery to increase vertical height of the atrophic mandible while vestibuloplasty is aimed to increase the denture bearing area. Purpose: The augmentation and vestibuloplasty was aimed to provide stability and retentive denture atrophic mandibular alveolar ridge. Case: A 65 years old woman patient complained about uncomfortable denture. Clinical evaluate showed flat ridge in the anterior mandible, flabby tissue and candidiasis, while residual ridge height was classified into class IV. Case management: Augmentation using autograph was conducted as the mandible vertical height is less than 15 mm. Autograph was used to achieve better bone quantity and quality. Separated alveolar ridge was conducted from left to right canine region and was elevated 0.5 mm from the previous position to get new ridge in the anterior region. The separated alveolar ridge was fixated by using T-plate and ligature wire. Three months after augmentation fixation appliances was removed vestibuloplasty was performed to increase denture bearing area that can make a stable and retentive denture. Conclusion: Augmentation and vestibuloplasty can improve flat ridge to become prominent.Latar belakang: Ridge mandibula yang atrofi pada umumnya mempersulit pembuatan restorasi prostetik terutama gigi tiruan lengkap (GTL. Residual alveolar ridge dan basal seat yang rendah menyebabkan gigi tiruan menjadi tidak stabil, menimbulkan ulser permanen, nyeri, neuralgia, dan kesulitan mengunyah. Tujuan: Augmentasi dan vestibuloplasti pada ridge mandibula yang atrofi dilakukan untuk menciptakan gigi tiruan yang stabil dan retentive. Kasus: Pasien wanita

Colors, colored overlays, and reading skills

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Arcangelo eUccula

2014-07-01

Full Text Available In this article, we are concerned with the role of colors in reading written texts. It has been argued that colored overlays applied above written texts positively influence both reading fluency and reading speed. These effects would be particularly evident for those individuals affected by the so called Meares-Irlen syndrome, i.e. who experience eyestrain and/or visual distortions – e.g. color, shape or movement illusions – while reading. This condition would interest the 12-14% of the general population and up to the 46% of the dyslexic population. Thus, colored overlays have been largely employed as a remedy for some aspects of the difficulties in reading experienced by dyslexic individuals, as fluency and speed. Despite the wide use of colored overlays, how they exert their effects has not been made clear yet. Also, according to some researchers, the results supporting the efficacy of colored overlays as a tool for helping readers are at least controversial. Furthermore, the very nature of the Meares-Irlen syndrome has been questioned. Here we provide a concise, critical review of the literature.

A randomised controlled trial of complete denture impression materials.

Science.gov (United States)

Hyde, T P; Craddock, H L; Gray, J C; Pavitt, S H; Hulme, C; Godfrey, M; Fernandez, C; Navarro-Coy, N; Dillon, S; Wright, J; Brown, S; Dukanovic, G; Brunton, P A

2014-08-01

There is continuing demand for non-implant prosthodontic treatment and yet there is a paucity of high quality Randomised Controlled Trial (RCT) evidence for best practice. The aim of this research was to provide evidence for best practice in prosthodontic impressions by comparing two impression materials in a double-blind, randomised, crossover, controlled, clinical trial. Eighty-five patients were recruited, using published eligibility criteria, to the trial at Leeds Dental Institute, UK. Each patient received two sets of dentures; made using either alginate or silicone impressions. Randomisations determined the order of assessment and order of impressions. The primary outcome was patient blinded preference for unadjusted dentures. Secondary outcomes were patient preference for the adjusted dentures, rating of comfort, stability and chewing efficiency, experience of each impression, and an OHIP-EDENT questionnaire. Seventy-eight (91.8%) patients completed the primary assessment. 53(67.9%) patients preferred dentures made from silicone impressions while 14(17.9%) preferred alginate impressions. 4(5.1%) patients found both dentures equally satisfactory and 7 (9.0%) found both equally unsatisfactory. There was a 50% difference in preference rates (in favour of silicone) (95%CI 32.7-67.3%, pUnilever Hatton Award of the International Assocation for Dental Research, Capetown, South Africa, June 2014. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

In-cell overlay metrology by using optical metrology tool

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Lee, Honggoo; Han, Sangjun; Hong, Minhyung; Kim, Seungyoung; Lee, Jieun; Lee, DongYoung; Oh, Eungryong; Choi, Ahlin; Park, Hyowon; Liang, Waley; Choi, DongSub; Kim, Nakyoon; Lee, Jeongpyo; Pandev, Stilian; Jeon, Sanghuck; Robinson, John C.

2018-03-01

Overlay is one of the most critical process control steps of semiconductor manufacturing technology. A typical advanced scheme includes an overlay feedback loop based on after litho optical imaging overlay metrology on scribeline targets. The after litho control loop typically involves high frequency sampling: every lot or nearly every lot. An after etch overlay metrology step is often included, at a lower sampling frequency, in order to characterize and compensate for bias. The after etch metrology step often involves CD-SEM metrology, in this case in-cell and ondevice. This work explores an alternative approach using spectroscopic ellipsometry (SE) metrology and a machine learning analysis technique. Advanced 1x nm DRAM wafers were prepared, including both nominal (POR) wafers with mean overlay offsets, as well as DOE wafers with intentional across wafer overlay modulation. After litho metrology was measured using optical imaging metrology, as well as after etch metrology using both SE and CD-SEM for comparison. We investigate 2 types of machine learning techniques with SE data: model-less and model-based, showing excellent performance for after etch in-cell on-device overlay metrology.

Occlusion and Temporomandibular Function among Subjects with Mandibular Distal Extension Removable Partial Dentures

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Creugers, N. H. J.; Witter, D. J.; Van 't Spijker, A.; Gerritsen, A. E.; Kreulen, C. M.

2010-01-01

Objective. To quantify effects on occlusion and temporomandibular function of mandibular distal extension removable partial dentures in shortened dental arches. Methods. Subjects wearing mandibular extension removable partial dentures (n = 25) were compared with subjects with shortened dental arches without extension (n = 74) and with subjects who had worn a mandibular extension removable partial denture in the past (n = 19). Subjects with complete dentitions (n = 72) were controls. Data were collected at baseline and at 3-, 6-, and 9-year observations. Results. Occlusal activity in terms of reported awareness of bruxism and occlusal tooth wear of lower anterior teeth did not differ significantly between the groups. In contrast, occlusal tooth wear of premolars in shortened dental arches with or without extension dentures was significantly higher than in the controls. Differences amongst groups with respect to signs and symptoms related to temporomandibular disorders were not found. Occlusal support of the dentures did not influence anterior spatial relationship. Occlusal contacts of the denture teeth decreased from 70% for second premolars via 50% for first molars, to 30% for second molars. Conclusions. Mandibular distal extension removable partial dentures in moderate shortened dental arches had no effects on occlusion and temporomandibular function. PMID:20671961

Hybrid overlay metrology with CDSEM in a BEOL patterning scheme

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Leray, Philippe; Jehoul, Christiane; Inoue, Osamu; Okagawa, Yutaka

2015-03-01

Overlay metrology accuracy is a major concern for our industry. Advanced logic process require more tighter overlay control for multipatterning schemes. TIS (Tool Induced Shift) and WIS (Wafer Induced Shift) are the main issues for IBO (Image Based Overlay) and DBO (Diffraction Based Overlay). Methods of compensation have been introduced, some are even very efficient to reduce these measured offsets. Another related question is about the overlay target designs. These targets are never fully representative of the design rules, strong efforts have been achieved, but the device cannot be completely duplicated. Ideally, we would like to measure in the device itself to verify the real overlay value. Top down CDSEM can measure critical dimensions of any structure, it is not dependent of specific target design. It can also measure the overlay errors but only in specific cases like LELE (Litho Etch Litho Etch) after final patterning. In this paper, we will revisit the capability of the CDSEM at final patterning by measuring overlay in dedicated targets as well as inside a logic and an SRAM design. In the dedicated overlay targets, we study the measurement differences between design rules gratings and relaxed pitch gratings. These relaxed pitch which are usually used in IBO or DBO targets. Beyond this "simple" LELE case, we will explore the capability of the CDSEM to measure overlay even if not at final patterning, at litho level. We will assess the hybridization of DBO and CDSEM for reference to optical tools after final patterning. We will show that these reference data can be used to validate the DBO overlay results (correctables and residual fingerprints).

The oral microbiome of denture wearers is influenced by levels of natural dentition

NARCIS (Netherlands)

O'Donnell, L.E.; Robertson, D.; Nile, C.J.; Cross, L.J.; Riggio, M.; Sherriff, A.; Bradshaw, D.; Lambert, M.; Malcolm, J.; Buijs, M.J.; Zaura, E.; Crielaard, W.; Brandt, B.W.; Ramage, G.

2015-01-01

Objectives The composition of dental plaque has been well defined, whereas currently there is limited understanding of the composition of denture plaque and how it directly influences denture related stomatitis (DS). The aims of this study were to compare the microbiomes of denture wearers, and to

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

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

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

Evaluating diffraction-based overlay

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Li, Jie; Tan, Asher; Jung, JinWoo; Goelzer, Gary; Smith, Nigel; Hu, Jiangtao; Ham, Boo-Hyun; Kwak, Min-Cheol; Kim, Cheol-Hong; Nam, Suk-Woo

2012-03-01

We evaluate diffraction-based overlay (DBO) metrology using two test wafers. The test wafers have different film stacks designed to test the quality of DBO data under a range of film conditions. We present DBO results using traditional empirical approach (eDBO). eDBO relies on linear response of the reflectance with respect to the overlay displacement within a small range. It requires specially designed targets that consist of multiple pads with programmed shifts. It offers convenience of quick recipe setup since there is no need to establish a model. We measure five DBO targets designed with different pitches and programmed shifts. The correlations of five eDBO targets and the correlation of eDBO to image-based overlay are excellent. The targets of 800nm and 600nm pitches have better dynamic precision than targets of 400nm pitch, which agrees with simulated results on signal/noise ratio. 3σ of less than 0.1nm is achieved for both wafers using the best configured targets. We further investigate the linearity assumption of eDBO algorithm. Simulation results indicate that as the pitch of DBO targets gets smaller, the nonlinearity error, i.e., the error in the overlay measurement results caused by deviation from ideal linear response, becomes bigger. We propose a nonlinearity correction (NLC) by including higher order terms in the optical response. The new algorithm with NLC improves measurement consistency for DBO targets of same pitch but different programmed shift, due to improved accuracy. The results from targets with different pitches, however, are improved marginally, indicating the presence of other error sources.

Oral manifestations of diabetes mellitus in complete denture wearers.

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Cristina de Lima, Danielle; Nakata, Gislaine Cristina; Balducci, Ivan; Almeida, Janete Dias

2008-01-01

The oral mucosa has been reported to show a variety of changes in subjects with diabetes mellitus. The purpose of this study was to compare diabetic and nondiabetic subjects wearing complete dentures with regard to salivary flow, salivary buffering capacity, denture retention, and oral mucosal lesions. Sixty subjects, 30 with and 30 without a diagnosis of diabetes, were matched for gender, race, and age. Salivary flow, salivary buffering capacity, glycemia, blood pressure, presence of mucosal lesions, denture retention, use of medications, and behavioral factors (controlled or uncontrolled diet, alcohol consumption, and smoking) reported by the subjects, were evaluated. For the salivary buffering capacity test, 1 mL of saliva was pipetted into a test tube containing 3 mL 0.005 N of hydrochloric acid, and the pH was measured with indicator strips. Group differences were statistically analyzed using the Student t test and the Mann-Whitney test for quantitative variables and the chi-square test for qualitative variables (alpha =.05). Mean (SD) salivary flow was 1.14 (0.87) mL/min in the nondiabetic subjects and 0.95 (0.61) mL/min in the diabetic subjects. Evaluation of self-reported denture retention revealed no significant difference between groups. Denture retention was observed in 66.7% (20/30) of the control group and in 50% (15/30) of the diabetic group. The prevalence of mucosal lesions was 90% (27/30) in the control group and 83.3% (25/30) in the diabetic group. Salivary buffering capacity was 5.80 (0.85) in the control group and 5.26 (0.83) in the diabetic group (P=.017). Within the limitations of this study, no significant differences were observed in salivary flow, denture retention, or oral lesions in diabetic and nondiabetic subjects.

Prevalence of Candida spp. among healthy denture and nondenture wearers with respect to hygiene and age

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Bharathi Prakash

2015-01-01

Full Text Available Dentures are inert and nonshading surfaces and therefore get easily colonized by Candida species. Subsequent biofilm produced by them lead to denture stomatitis and candidiasis. This study was aimed to understand the prevalence of Candida species among healthy denture and nondenture wearers with respect to their age and hygiene status. Swabs were collected from 50 complete dentures and 50 non-denture wearers and processed on Sabouraud′s dextrose agar. Identification of Candida species was done by staining and a battery of biochemical tests. Data obtained was correlated with age & oral hygiene and statistical analysis was performed. Candida was isolated from both denture and nondenture wearers. Prevalence of different Candida species was significantly higher in denture wearers and found predominated by C. albicans, C. tropicalis, C. dubliensis and C. glabrata. Among nondenture wearers, C. albicans and C. tropicalis were isolated. Prevalence of Candida increased with increasing age among denture wearers. Men presented declining denture hygiene compared to women with increasing age. In comparison to nondenture wearers, multispecies of Candida colonized the dentures thus presenting higher risk of candidiasis especially with increasing age.

Development of chair-side evaluation system of swallowing discomfort of denture wearers

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Matsumoto, Keisuke; Ikuta, Ryuhei; Kataoka, Kanako; Ono, Yumie; Tamaki, Katsushi

2018-02-01

We investigated the appropriate hemodynamic parameters of functional near-infrared spectroscopy (fNIRS) to best differentiate the discomfort intensity related to swallowing in healthy subjects wearing different types of simulated dentures. Thirty-one subjects performed 4 sessions of water-swallowing task in a sitting position without or with wearing any one of the 3 simulated dentures under continuous fNIRS monitoring of the prefrontal cortex. The simulated dentures were consisted of a flat maxillary palatal bar and bilateral support attachment to the teeth and gum. The palatal bar positions were arranged along with the anterior, middle, or posterior areas of the upper jaw. The cumulative values of oxyhemoglobin and deoxyhemoglobin concentration changes were calculated for periods of 5 - 10 s from completion of swallowing. Subjective rating of swallowing-discomfort was the lowest without wearing denture and increased along with the palatal bar position placed from anterior to posterior. Cumulated deoxyhemoglobin signals calculated for 10 s post-swallowing event in the left frontopolar prefrontal cortex showed the best correlation with the subjective rating of discomfort in swallowing with dentures. These neurological signatures would be beneficial to detect swallowing discomfort in elderly denture wearers who have difficulty in communicating with dentists.

The effect of a commercial probiotic drink on oral microbiota in healthy complete denture wearers

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Justyna Sutula

2012-10-01

Full Text Available Background : It is acknowledged that oral and general health status declines with age. The global population of denture wearers is increasing, so is the incidence of denture biofilm-related problems, such as denture-associated stomatitis, aspiration pneumonia and malodour. It has been suggested that consumption of probiotic bacteria may improve oral health. However, the effects of probiotics on the oral microbiota of denture wearers have received little attention. Methods : The aim of this study was to investigate the effect of consumption of a commercial probiotic product (Yakult on microbiota of saliva, tongue and denture biofilm in healthy complete denture wearers. Eight healthy complete denture-wearing National Health Service (NHS patients undertook a 7-week trial comprising three phases: baseline; 4-week consumption of one bottle of Yakult per day, each containing a minimum 6.5×109 viable cells of Lactobacillus casei strain Shirota (LcS; 4-week washout period. The microbial viability and composition of saliva, tongue dorsum coating and denture biofilm were assessed using a range of solid selective and indicator media. Questionnaires were used to explore participants’ denture cleaning habits and impact of wearing dentures on their life quality and well-being [modified oral health impact profile (OHIP-14] prior to and after the study. Results : Seven volunteers (1 male, 6 females completed the trial. LcS temporarily colonised oral cavity and denture surface. There was no significant change in the viability of Streptococcus mutans, acidogenic microorganisms, total anaerobic species and Gram-negative obligate anaerobes between study phases. There was no obvious effect of LcS on occurrence and viability of Candida. Participants presented a good general knowledge of denture hygiene and their responses to OHIP-14 questionnaires improved after completing the study (p=0.16. Conclusion : It appeared that 4-week consumption of probiotic drink had

[Longitudinal survey and analysis among Chengdu residents on cognition and acceptance of implant dentures].

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Zuo, Yanping; Wang, Yongyue; Wang, Luming; Du, Bing

2014-08-01

This study aims to survey the cognition and acceptance of implant dentures among Chengdu residents in 2005 and 2013 and to comparatively analyze the differences and influencing factors. A questionnaire was designed for this study. Its main content included basic demographics of respondents (gender, age, cultural level, and income level), cognition level of implant dentures (concept and main characteristics of implant dentures), main concern of respondents regarding implant dentures and medical institutions, and acceptance level of the price of implant dentures, among others. The sampling survey was carried out among Chengdu residents in 2005 and 2013 using the designed questionnaire. The results were then statistically analyzed. Up to 908 valid questionnaires in 2005 and 905 valid questionnaires in 2013 were obtained. The level of cognition of implant dentures was higher in 2013 than in 2005, and the correlation between cognition and cultural level and that between cognition and income level were both positive. However, the correlation between cognition and age was negative. The success rate for implant dentures and medical treatment technology of medical institutions were the factors that the respondents were mainly concerned with. The main methods for disseminating information on implant dentures were the internet, television, newspapers, magazines, and introduction by friends. With the development of the society's economy and the improvement of culture and income level of Chengdu residents, the cognition and acceptance level of implant dentures have gradualy increased. Meanwhile, health education and medical technology still need to be strengthened.

Impact of mandibular conventional denture and overdenture on quality of life and masticatory efficiency

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Rachel Gomes CARDOSO

Full Text Available Abstract The aim of this non-randomized controlled clinical trial was to evaluate the oral health-related quality of life and masticatory efficiency of patients rehabilitated with mandibular two-implant overdentures with immediate loading or conventional dentures. Fifty completely edentulous patients wearing bimaxillary conventional dentures, for at least one year, were recruited. The patients were then assigned to either two treatment groups: mandibular overdentures supported by two implants with bar-clip system and a maxillary conventional denture (n = 25, and new maxillary and mandibular conventional complete dentures (n = 25. Masticatory efficiency and oral health-related quality of life were assessed before and 3 months after denture insertion. The Brazilian version of OHIP-Edent questionnaire was used to assess the oral health-related quality of life. Masticatory efficiency was evaluated with chewing capsules through a colorimetric method. The results revealed fewer oral health–related quality of life problems in patients wearing mandibular two-implant overdentures compared to the conventional dentures group. In addition, the implant overdenture group presented statistically significant improvement in masticatory efficiency (p = 0.001. There was no correlation between masticatory efficiency and OHIP in the implant group (p > 0.05, however a correlation was found in the conventional denture group (p < 0.05. Therefore, these short-term results suggest that mandibular overdenture retained by 2 implants with immediate loading combined with maxillary conventional dentures provide better masticatory efficiency and oral health–related quality of life than mandibular conventional dentures.

Sectional mandibular complete denture for a total maxillectomy patient with trismus: a clinical report.

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Celakil, Tamer; Demir, Azize; Keskin, Haluk

2017-01-01

This report presents the case of a 60-year-old male patient with trismus induced by radiotherapy and fabrication of a sectional mandibular complete denture to allow the insertion of the denture into the mouth. A mandibular sectional denture was designed in two pieces with a locking mechanism by using mini anchor and ball abutment housing with cap. Patients who have undergone maxillectomy often have constricted mouth openings, as a result of surgical intervention and radiotherapy, and complain of an inability to insert or remove dentures. A new approach is vital for sectional dentures because existing sectional denture fabrication techniques cannot meet the ongoing needs of trismus patients. The mini anchor system with ball abutment housing has better mechanical retention in acrylic resin and can provide favorable stabilization during masticatory function; thus, additional framework is not required for assisting in stabilization and retention.

The Use of Implants to Improve Removable Partial Denture Function.

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Pimentel, Marcele Jardim; Arréllaga, Juan Pablo; Bacchi, Ataís; Del Bel Cury, Altair A

2014-12-01

The oral rehabilitation with conventional removable partial dentures in Kennedy class I patients allows continuous bone resorption, dislodgment of the prosthesis during the mastication caused by the resilience of the mucosa, and rotation of the prosthesis. Thus, the associations of distal implants become an attractive modality of treatment for these patients. This case report presented an association of removable partial dentures, milled crowns and osseointegrated implants to rehabilitate a partial edentulous patient. A removable partial denture associated with implants and metal-ceramic milled crowns can offer excellent esthetics, and will improve function and biomechanics, at a reduced cost.

Perceived effects of coloured overlays on reading material in persons with albinism

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N. T. Makgaba

2008-12-01

Full Text Available Persons with albinism often complain of glare when reading. They may therefore benefit from coloured filter overlays just as they benefit from tinted lenses. The purpose of this study was to assess the effectof coloured overlays on print perception in persons with oculocutaneous albinism (OCA.   Fifty subjects were included in this study, their ages ranged from 12 to 31 years with a mean of 16.12 years (SD = ± 4.56 years.  Following refraction and subsequent compensation for refractive errors, subjective perception of print was examined with the subject looking at the Wilkins® reading rate test chart with and without colored filter overlay/s.  The subjects were asked to respond to questions previously used in a questionnaire by Wilkins (2001. The percentage frequencies of positive (beneficial responses were used to decide whether or not a particular overlay would enhance reading performance.  McNemar’s test was used to establish significant differences between responses to questions without and with overlays. All single overlays gave greater percentages of positive responses (92.0-97.2% than without overlay (85.2%.  The single overlay that provided the highest positive responses was blue (97.2% and the least was purple (92.0%. All double overlays, except grey/grey (82.0% gave greater positive responses than without overlay (85.2%. Aqua/blue gave the greatest positive responses (possible benefits (97.2%, followed by rose/rose (96.8%.  Comparing the responses without overlay with single and double overlays, the difference in responses to the five questions was only significant (p < 0.05 with regard to brightness of the surface. The results suggest that overlays provided a more glare-free reading surface than without an overlay. It was, therefore concluded that the best advantage of the coloured overlays was in glare reduction.  Although this study showed that there were more subjects who preferred single blue and aqua/blue double

Hybrid approach to fabrication of hollow internally weighted mandibular denture: A case report.

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Hazari, Puja; Mishra, Sunil Kumar

2015-08-01

Preservation of ridge dimensions is critical for denture success. For long the concept of an internally weighted denture, which suggested that gravity and the additional weight to the mandibular complete denture aids in prosthetic retention is widely accepted. However, excessive weight and pressure can accelerate bone resorption. Here, we describe a unique modification of internally weighted metal denture base for the resorbed mandibular ridge with an incorporated additional hollow section over the anterior knife-edge ridge. The weight provided retention and stability while the hollow portion prevented further resorption of the bone.

Robotic weld overlay coatings for erosion control

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The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB's.

Load transfer characteristics of unilateral distal extension removable partial dentures with polyacetal resin supporting components.

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Jiao, T; Chang, T; Caputo, A A

2009-03-01

To photoelastically examine load transfer by unilateral distal extension removable partial dentures with supporting and retentive components made of the lower stiffness polyacetal resins. A mandibular photoelastic model, with edentulous space distal to the right second premolar and missing the left first molar, was constructed to determine the load transmission characteristics of a unilateral distal extension base removable partial denture. Individual simulants were used for tooth structure, periodontal ligament, and alveolar bone. Three designs were fabricated: a major connector and clasps made from polyacetal resin, a metal framework as the major connector with polyacetal resin clasp and denture base, and a traditional metal framework I-bar removable partial denture. Simulated posterior bilateral and unilateral occlusal loads were applied to the removable partial dentures. Under bilateral and left side unilateral loading, the highest stress was observed adjacent to the left side posterior teeth with the polyacetal removable partial denture. The lowest stress was seen with the traditional metal framework. Unilateral loads on the right edentulous region produced similar distributed stress under the denture base with all three designs but a somewhat higher intensity with the polyacetal framework. The polyacetal resin removable partial denture concentrated the highest stresses to the abutment and the bone. The traditional metal framework I-bar removable partial denture most equitably distributed force. The hybrid design that combined a metal framework and polyacetal clasp and denture base may be a viable alternative when aesthetics are of primary concern.

Occlusion and Temporomandibular Function among Subjects with Mandibular Distal Extension Removable Partial Dentures

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N. H. J. Creugers

2010-01-01

Full Text Available Objective. To quantify effects on occlusion and temporomandibular function of mandibular distal extension removable partial dentures in shortened dental arches. Methods. Subjects wearing mandibular extension removable partial dentures (n=25 were compared with subjects with shortened dental arches without extension (n=74 and with subjects who had worn a mandibular extension removable partial denture in the past (n=19. Subjects with complete dentitions (n=72 were controls. Data were collected at baseline and at 3-, 6-, and 9-year observations. Results. Occlusal activity in terms of reported awareness of bruxism and occlusal tooth wear of lower anterior teeth did not differ significantly between the groups. In contrast, occlusal tooth wear of premolars in shortened dental arches with or without extension dentures was significantly higher than in the controls. Differences amongst groups with respect to signs and symptoms related to temporomandibular disorders were not found. Occlusal support of the dentures did not influence anterior spatial relationship. Occlusal contacts of the denture teeth decreased from 70% for second premolars via 50% for first molars, to 30% for second molars. Conclusions. Mandibular distal extension removable partial dentures in moderate shortened dental arches had no effects on occlusion and temporomandibular function.

Provision of a swing lock denture for a patient with Gorlin Goltz syndrome.

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Razaq, I; Durey, K; Nattress, B

2012-09-01

Swinglock dentures are used relatively infrequently but in cases of compromised anatomy or where the pattern of tooth loss is unfavourable, they provide a useful removable partial denture design option. The aim of this article is to provide a clear summary of the clinical and technical considerations necessary when providing a Swinglock denture.

Comparison of Fit of Dentures Fabricated by Traditional Techniques Versus CAD/CAM Technology.

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McLaughlin, J Bryan; Ramos, Van; Dickinson, Douglas P

2017-11-14

To compare the shrinkage of denture bases fabricated by three methods: CAD/CAM, compression molding, and injection molding. The effect of arch form and palate depth was also tested. Nine titanium casts, representing combinations of tapered, ovoid, and square arch forms and shallow, medium, and deep palate depths, were fabricated using electron beam melting (EBM) technology. For each base fabrication method, three poly(vinyl siloxane) impressions were made from each cast, 27 dentures for each method. Compression-molded dentures were fabricated using Lucitone 199 poly methyl methacrylate (PMMA), and injection molded dentures with Ivobase's Hybrid Pink PMMA. For CAD/CAM, denture bases were designed and milled by Avadent using their Light PMMA. To quantify the space between the denture and the master cast, silicone duplicating material was placed in the intaglio of the dentures, the titanium master cast was seated under pressure, and the silicone was then trimmed and recovered. Three silicone measurements per denture were recorded, for a total of 243 measurements. Each silicone measurement was weighed and adjusted to the surface area of the respective arch, giving an average and standard deviation for each denture. Comparison of manufacturing methods showed a statistically significant difference (p = 0.0001). Using a ratio of the means, compression molding had on average 41% to 47% more space than injection molding and CAD/CAM. Comparison of arch/palate forms showed a statistically significant difference (p = 0.023), with shallow palate forms having more space with compression molding. The ovoid shallow form showed CAD/CAM and compression molding had more space than injection molding. Overall, injection molding and CAD/CAM fabrication methods produced equally well-fitting dentures, with both having a better fit than compression molding. Shallow palates appear to be more affected by shrinkage than medium or deep palates. Shallow ovoid arch forms appear to benefit from

[Gerontoprosthesis. Concept of rebuilding old complete dentures].

Science.gov (United States)

Marxkors, R; Mayer, K

1990-04-01

If aged patients who have been wearing their full dentures without complications so far, need further prothetic treatment, the dentist must not replace the old denture by a completely new one. It is better to rebuild it step by step. This demand is based on the following theses: --Nobody but the patient himself is able to perform functional movements. --Unless bite and occlusion are correct, patients are not able to perform accurate functional movements. --When bite and occlusion have been checked and, if necessary, improved, bases and alveolar ridges must be congruent.

The Oral Microbiome of Denture Wearers Is Influenced by Levels of Natural Dentition

Science.gov (United States)

O’Donnell, Lindsay E.; Robertson, Douglas; Nile, Christopher J.; Cross, Laura J.; Riggio, Marcello; Sherriff, Andrea; Bradshaw, David; Lambert, Margaret; Malcolm, Jennifer; Buijs, Mark J.; Zaura, Egija; Crielaard, Wim; Brandt, Bernd W.; Ramage, Gordon

2015-01-01

Objectives The composition of dental plaque has been well defined, whereas currently there is limited understanding of the composition of denture plaque and how it directly influences denture related stomatitis (DS). The aims of this study were to compare the microbiomes of denture wearers, and to understand the implications of these towards inter-kingdom and host-pathogen interactions within the oral cavity. Methods Swab samples were obtained from 123 participants wearing either a complete or partial denture; the bacterial composition of each sample was determined using bar-coded illumina MiSeq sequencing of the bacterial hypervariable V4 region of 16S rDNA. Sequencing data processing was undertaken using QIIME, clustered in Operational Taxonomic Units (OTUs) and assigned to taxonomy. The dentures were sonicated to remove the microbial flora residing on the prosthesis, sonicate was then cultured using diagnostic colorex Candida media. Samples of unstimulated saliva were obtained and antimicrobial peptides (AMP) levels were measured by ELISA. Results We have shown that dental and denture plaques are significantly distinct both in composition and diversity and that the oral microbiome composition of a denture wearer is variable and is influenced by the location within the mouth. Dentures and mucosa were predominantly made up of Bacilli and Actinobacteria. Moreover, the presence of natural teeth has a significant impact on the overall microbial composition, when compared to the fully edentulous. Furthermore, increasing levels of Candida spp. positively correlate with Lactobacillus spp. AMPs were quantified, though showed no specific correlations. Conclusions This is the first study to provide a detailed understanding of the oral microbiome of denture wearers and has provided evidence that DS development is more complex than simply a candidal infection. Both fungal and bacterial kingdoms clearly play a role in defining the progression of DS, though we were unable to

Diminished Antimicrobial Peptide and Antifungal Antibiotic Activities against Candida albicans in Denture Adhesive

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Amber M. Bates

2017-02-01

Full Text Available The underlying causes of denture stomatitis may be related to the long-term use of adhesives, which may predispose individuals to oral candidiasis. In this study, we hypothesize that antimicrobial peptides and antifungal antibiotics have diminished anti-Candida activities in denture adhesive. To show this, nine antimicrobial peptides and five antifungal antibiotics with and without 1.0% denture adhesive were incubated with Candida albicans strains ATCC 64124 and HMV4C in radial diffusion assays. In gels with 1.0% adhesive, HNP-1, HBD2, HBD3, IP-10, LL37 (only one strain, histatin 5 (only one strain, lactoferricin B, and SMAP28 showed diminished activity against C. albicans. In gels with 1.0% adhesive, amphotericin B and chlorhexidine dihydrochloride were active against both strains of C. albicans. These results suggest that denture adhesive may inactivate innate immune mediators in the oral cavity increasing the risk of C. albicans infections, but inclusion of antifungal antibiotics to denture adhesive may aid in prevention or treatment of Candida infections and denture stomatitis.

SECTIONAL MANDIBULAR COMPLETE DENTURE FOR A TOTAL MAXILLECTOMY PATIENT WITH TRISMUS: A CLINICAL REPORT

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Tamer ÇELAKIL

2017-10-01

Full Text Available This report presents the case of a 60-year-old male patient with trismus induced by radiotherapy and fabrication of a sectional mandibular complete denture to allow the insertion of the denture into the mouth. A mandibular sectional denture was designed in two pieces with a locking mechanism by using mini anchor and ball abutment housing with cap. Patients who have undergone maxillectomy often have constricted mouth openings, as a result of surgical intervention and radiotherapy, and complain of an inability to insert or remove dentures. A new approach is vital for sectional dentures because existing sectional denture fabrication techniques cannot meet the ongoing needs of trismus patients. The mini anchor system with ball abutment housing has better mechanical retention in acrylic resin and can provide favorable stabilization during masticatory function; thus, additional framework is not required for assisting in stabilization and retention.

Inhibitory effects of Lactobacillus rhamnosus and Lactobacillus casei on Candida biofilm of denture surface.

Science.gov (United States)

Song, Young-Gyun; Lee, Sung-Hoon

2017-04-01

Candida albicans biofilm is associated with denture-related stomatitis and oral candidiasis of elderly. Probiotics are beneficial bacteria and have antibacterial activity against pathogenic bacteria. The purpose of this study was to investigate the antifungal activity of various probiotics against C. albicans and the inhibitory effects of probiotics on Candida biofilm on the denture surface. The spent culture media of various probiotics were investigated the antifungal efficacy against C. albicans. Candida biofilm was formed on a denture base resin and was then treated with Lactobacillus rhamnosus and Lactobacillus casei. Also, the biofilms of L. rhamnosus and L. casei were formed and were sequentially treated with C. albicans. Colony-forming units of C. albicans on the denture surface were counted after spreading on agar plate. The denture base resin was treated with the spent culture media for 30days, after which the denture surface roughness was analyzed with an atomic force microscope. L. rhamnosus and L. casei exhibited stronger antifungal activity than other probiotics. The spent culture medium of L. rhamnosus and L. casei exhibited the antifungal activity against blastoconidia and biofilm of C. albicans. L. rhamnosus and L. casei showed the antifungal activity against Candida biofilm, and the biofilm of L. rhamnosus and L. casei inhibited formation of Candida biofilm on denture surface. Neither of the probiotics affected the surface roughness of the denture base resin. L. rhamnosus and L. casei may be the ideal probiotics for the prevention and treatment of denture-related stomatitis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Expectations and final evaluation of complete dentures by patients, dentist and dental technician.

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Marachlioglou, C R M Z; Dos Santos, J F F; Cunha, V P P; Marchini, Leonardo

2010-07-01

There is a poor association between the dentist's evaluation of denture quality and patients' satisfaction with their dentures. Possible differences between dental professionals and patients' expectations might help explain differences in outcome evaluations. This study compared scores given by a dentist, a dental technician and patients for their expectations before and their final evaluation after complete dentures treatment. Twenty completely edentulous patients, a prosthodontist and a dental technician provided scores for the expected aesthetic and functional results of their dentures based on a visual analogue scale at baseline. Post-treatment completion ratings were given after adjustments, by dentist and patients. The dental technician provided post-treatment completion ratings after completing the dentures. The patients had higher expectations than the dental technician and the dentist perceived for both aesthetic and function (P < 0.001). The patients also presented higher post-treatment completion ratings than the dental professionals perceived for final aesthetics (P = 0.016, Kendall's W = 0.207) and function (P = 0.002, Kendall's W = 0.303). Only the dentist presented a statistically significant difference between expectations (lower) and final (higher) outcomes for aesthetics (P = 0.017) and function (P = 0.003). There was no correlation between expectations and post-treatment completion ratings according to the patients' age. There was also no correlation between the patients' gender and expectation scores. Patients presented higher expectations regarding their dentures than dental professionals. The dentist believed that dentures would bring fewer benefits than patients did, but his perception of denture benefits post-treatment was significantly higher than his expectations.

Ablative overlays for Space Shuttle leading edge ascent heat protection

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Strauss, E. L.

1975-01-01

Ablative overlays were evaluated via a plasma-arc simulation of the ascent pulse on the leading edge of the Space Shuttle Orbiter. Overlay concepts included corkboard, polyisocyanurate foam, low-density Teflon, epoxy, and subliming salts. Their densities ranged from 4.9 to 81 lb per cu ft, and the thicknesses varied from 0.107 to 0.330 in. Swept-leading-edge models were fabricated from 30-lb per cu ft silicone-based ablators. The overlays were bonded to maintain the surface temperature of the base ablator below 500 F during ascent. Foams provided minimum-weight overlays, and subliming salts provided minimum-thickness overlays. Teflon left the most uniform surface after ascent heating.

Collation of chewing efficiency and dentures with diverse occlusal schemes

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Vijay Kumar Peddinti

2017-01-01

Full Text Available Background: Rehabilitation of an edentulous patient nurtures satisfaction and this lies in the chewing ability provided by the prosthesis. Aim: To evaluate and compare the masticatory efficiencies of complete dentures with different occlusal schemes. Materials and Methods: Fourteen completely edentulous patients from the age group of 50-70 years were selected according to the inclusion criteria followed in this study. The dentures were made with three different occlusal schemes, i.e., anatomic occlusion without balancing, anatomic occlusion with balancing, and lingualized occlusion and stored in water till the date of denture insertion. Post-insertion instructions were given to the patients at the time of delivery of the dentures. Patients were recalled after seven days and then masticatory efficiency was performed. The test was performed using boiled peanuts and Sieve system. Statistical Analysis: One-way analysis of variance (ANOVA test and unpaired t-test were carried out. Results: The obtained masticatory efficiency values with anatomic occlusion without balancing, anatomic occlusion with balancing, and lingualized occlusion LO were analyzed using one-way ANOVA test and unpaired “t” test. The tests showed that lingualized scheme had highest masticatory efficiency. Conclusion: Within the scope of this study, it can be concluded that the masticatory efficiency will be generally higher in patients provided with complete dentures fabricated using the lingualized occlusal scheme.

Tack coat optimization for HMA overlays laboratory testing.

Science.gov (United States)

2008-09-01

Interface bonding between hot-mix asphalt (HMA) overlays and Portland cement concrete (PCC) pavements can be one of the most : significant factors affecting overlay service life. Various factors may affect the bonding condition at the interface, incl...

Enhancing retention of partial dentures using elastomeric retention rings

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Kakkirala Revathi

2015-01-01

Full Text Available This report presents an alternative method for the retention of partial dentures that relies on the engagement of tooth undercuts by a lining material. The lab procedures are also presented. A new maxillary and mandibular acrylic partial dentures were fabricated using elastomeric retention technique for a partially dentate patient. A partially dentate man reported difficulty in retaining his upper removable partial denture (RPD. The maxillary RPD was designed utilizing elastomeric retention technique. During follow-up, it was necessary to replace the retention rings due to wear. The replacement of the retention rings, in this case, was done through a chairside reline technique. Elastomeric retention technique provides exceptionally good retention can be indicated to stabilize, cushion, splint periodontally involved teeth, no enough undercut for clasps, eliminate extractions, single or isolated teeth.

Connection of functional quality of partial removable dentures and the degree of patients' phonetic adaptation.

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Artjomenko, Victoria; Vidzis, Aldis; Zigurs, Guntis

2015-01-01

Phonetic adaptation is a complex biological phenomenon with a highly individual course, depending on the patient's motivation to use prosthesis, on the functional quality of removable dentures. The aim of the study was to estimate phonetic adaptation in patients with partial dentures, connecting it to alteration in speech quality and dentures functional value. We examined some peculiarities of phonetic adaptation in 50 patients with removable dentures (50 patients with natural dentition were invited for the control group). The standardized evaluation protocols (12 speech quality determining parameters) were developed separately for Latvian and Russian native speakers. 500 speech video samples were recorded and analysed according to pre-established guidelines. The connection of speech quality and the functional quality of the dentures was assessed. Statistical analysis was performed using SPSS 20.0. P values equal to or less than 0.05 were considered to be statistically significant. In patients with appropriate functional quality of removable dentures distorted speech production was detected in 25% (pk=0.008) cases and in patients with inappropriate functional quality of the prosthesis - in 40% (pkdentures functional value were satisfied with their speech performance in 96% (pk=0.674), in the group with inappropriate dentures functional value only 59% (premovable dentures depends on the patient's individual adaptation capacity, prosthetic design and functional value. Thus statistically significant correlation between removable partial dentures functional value, duration of usage and the degree of patients' phonetic adaptation (p<0.001) may be considered to be confirmed.

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

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Sehgal, Komal

2014-01-01

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

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

Science.gov (United States)

Kumar, Lalit; Sehgal, Komal

2014-06-01

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

Etiological factors correlated with temporomandibular disorder in complete denture wearers: a comparative analysis

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Ricardo Alexandre Zavanelli

2009-01-01

Full Text Available Objective: The aim of this study was to make a comparative evaluation of the prevalence of temporomandibular disorder in complete denturewearers, with regard to the etiological factors, such as gender, age, and complete dentures clinical conditions, according to the anamnestic(Ai and clinical (Di dysfunction index, developed by Helkimo.Methods: The randomized sample was composed of 90 institutionalized patients and bimaxillary complete denture wearers, with a mean ageof 67.2 years, who were included in this study. The collected data were tabulated and the Kruskal-Wallis and Chi-square statistical tests were applied, at the level of significance of 5% (p<0.05.Results: Statistically significant difference in the prevalence of temporomandibular disorder was observed with regard to the ages of the current complete dentures, free-way space, wear of the occlusal surfaces of the artificial teeth, and the conditions of retention and stability of the maxillary and mandibular complete dentures, according to both the indexes. Conclusion: The patients who wore complete dentures in adequate clinical conditions presented fewer signs and symptoms of temporomandibular disorder than the patients who wore complete dentures in poor clinical conditions.

Vinegar as an antimicrobial agent for control of Candida spp. in complete denture wearers

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Telma Maria Silva Pinto

2008-12-01

Full Text Available The use of denture is known to increase the carriage of Candida in healthy patients, and the proliferation of Candida albicans strains can be associated with denture-induced stomatitis. The aim of this study was to evaluate the use of vinegar as an antimicrobial agent for control of Candida spp. in complete upper denture wearers. Fifty-five patients were submitted to a detailed clinical interview and oral clinical examination, and were instructed to keep their dentures immersed in a 10% vinegar solution (pH less than 3 overnight for 45 days. Before and after the experimental period, saliva samples were collected for detection of Candida, counting of cfu/mL and identification of species by phenotypical tests (germ tube formation, chlamidoconidia production, and carbohydrate fermentation and assimilation. The results were analyzed using Spearman's correlation and Student's t-test (p£0.05. Candida yeasts were present in 87.3% of saliva samples before the treatment. A significant reduction was verified in CFU/mL counts of Candida after treatment. A positive correlation between Candida and denture stomatitis was verified, since the decrease of cfu/mL counts was correlated with a reduction in cases of denture stomatitis. Although it was not able to eliminate C. albicans, the immersion of the complete denture in 10% vinegar solution, during the night, reduced the amounts (cfu/mL of Candida spp. in the saliva and the presence of denture stomatitis in the studied patients.

Conventional Complete Denture in Patients with Ectodermal Dysplasia

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Larissa Soares Reis Vilanova

2015-01-01

Full Text Available Ectodermal dysplasia is described as heritable conditions that involve anomalies of structures derived from the ectoderm, including hypodontia. In the cases of edentulous young patients, who did not finish their craniofacial growth, treatment with conventional complete denture is a suitable alternative. The aim of this study was to report a case of mandibular edentulism treated with conventional complete denture in a thirteen-year-old patient diagnosed with hidrotic ectodermal dysplasia. Typical features, such as frontal bossing, depressed nasal bridge, protuberant lips, scarce hair, and brittle nails, were visualized during the extraoral examination. The intraoral inspection and radiographic analysis revealed oligodontia, dental malformation, and prolonged retention of deciduous teeth at maxilla and total edentulism at mandible. A conventional complete denture was planned and constructed following the same steps of technique as recommended in adults. Although this option is not a definitive treatment, the patient and his parents were satisfied with his improvement in chewing and speech, as well as with the aesthetic benefits.

Cytotoxicity of four denture adhesives on human gingival fibroblast cells.

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Lee, Yoon; Ahn, Jin-Soo; Yi, Young-Ah; Chung, Shin-Hye; Yoo, Yeon-Jee; Ju, Sung-Won; Hwang, Ji-Yun; Seo, Deog-Gyu

2015-02-01

The purpose of this study was to compare the cytotoxicity of four denture adhesives on human gingival fibroblast cells. Immortalized human gingival fibroblasts were cultured with one of four different denture adhesives, Polident, Protefix, Staydent or Denfix-A, which was placed in insert dishes (10% w/v concentration) for 48 h. The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and flow cytometric apoptosis assay were used to evaluate cell viability and apoptosis rates. The fibroblasts were also examined under a scanning electron microscope. The MTT assay showed that all denture adhesives resulted in a significantly lower cell viability compared to the control cells propagated in normal culture medium (p 0.05). Staydent showed the highest apoptosis rate. Scanning electron microscopy showed that the cells of the Staydent group underwent cytoplasmic membrane shrinkage, with cell free areas containing residual fragments of the membrane of dead cells. The four denture adhesives evaluated in this study imparted cytotoxic effects on human gingival fibroblast cells. Staydent showed the highest toxicity.

Patient's Satisfaction with Removable Partial Dentures: A Retrospective Case Series.

Science.gov (United States)

Shala, Kujtim Sh; Dula, Linda J; Pustina-Krasniqi, Teuta; Bicaj, Teuta; Ahmedi, Enis F; Lila-Krasniqi, Zana; Tmava-Dragusha, Arlinda

2016-01-01

This retrospective clinical study aimed to assess patient's satisfaction with removable partial dentures (RPDs), as retention, chewing ability, aesthetics during the observation period. A total of 63 patients with RPDs, participated in this study. The following data was collected: Kennedy classification, denture design, denture support, satisfaction and success of RPD. The results showed that 73.6% of patients were wearing RPD for the first time and were finally satisfied. According to the denture support of RPDs, clasp-retained quadrangular RPDs were 100% effective, followed by triangular dental support 81% and linear dental support 47.7%. Comparison of RPDs with attachment with RPDs with claps assessed through Fisher exact test, confirmed statistically significant difference (P=0.008), despite retention; however, chewing ability and aesthetics showed no statistically significant difference with X 2 test on patient's satisfaction with RPD with or without attachment. Patients often would prefer not showing the anterior buccal clasps of RPD, therefore are generally satisfied more with RPD with attachment based on level of retention, chewing ability and aesthetics.

Effect of biofilm formation, and biocorrosion on denture base fractures.

Science.gov (United States)

Sahin, Cem; Ergin, Alper; Ayyildiz, Simel; Cosgun, Erdal; Uzun, Gulay

2013-05-01

The aim of this study was to investigate the destructive effects of biofilm formation and/or biocorrosive activity of 6 different oral microorganisms. Three different heat polymerized acrylic resins (Ivocap Plus, Lucitone 550, QC 20) were used to prepare three different types of samples. Type "A" samples with "V" type notch was used to measure the fracture strength, "B" type to evaluate the surfaces with scanning electron microscopy and "C" type for quantitative biofilm assay. Development and calculation of biofilm covered surfaces on denture base materials were accomplished by SEM and quantitative biofilm assay. According to normality assumptions ANOVA or Kruskal-Wallis was selected for statistical analysis (α=0.05). Significant differences were obtained among the adhesion potential of 6 different microorganisms and there were significant differences among their adhesion onto 3 different denture base materials. Compared to the control groups after contamination with the microorganisms, the three point bending test values of denture base materials decreased significantly (P.05). All the tested microorganisms had destructive effect over the structure and composition of the denture base materials.

Accuracy optimization with wavelength tunability in overlay imaging technology

Science.gov (United States)

Lee, Honggoo; Kang, Yoonshik; Han, Sangjoon; Shim, Kyuchan; Hong, Minhyung; Kim, Seungyoung; Lee, Jieun; Lee, Dongyoung; Oh, Eungryong; Choi, Ahlin; Kim, Youngsik; Marciano, Tal; Klein, Dana; Hajaj, Eitan M.; Aharon, Sharon; Ben-Dov, Guy; Lilach, Saltoun; Serero, Dan; Golotsvan, Anna

2018-03-01

As semiconductor manufacturing technology progresses and the dimensions of integrated circuit elements shrink, overlay budget is accordingly being reduced. Overlay budget closely approaches the scale of measurement inaccuracies due to both optical imperfections of the measurement system and the interaction of light with geometrical asymmetries of the measured targets. Measurement inaccuracies can no longer be ignored due to their significant effect on the resulting device yield. In this paper we investigate a new approach for imaging based overlay (IBO) measurements by optimizing accuracy rather than contrast precision, including its effect over the total target performance, using wavelength tunable overlay imaging metrology. We present new accuracy metrics based on theoretical development and present their quality in identifying the measurement accuracy when compared to CD-SEM overlay measurements. The paper presents the theoretical considerations and simulation work, as well as measurement data, for which tunability combined with the new accuracy metrics is shown to improve accuracy performance.

Denture identification using unique identification authority of India barcode

OpenAIRE

Sudhindra Mahoorkar; Anoop Jain

2013-01-01

Over the years, various denture marking systems have been reported in the literature for personal identification. They have been broadly divided into surface marking and inclusion methods. In this technique, patient's unique identification number and barcode printed in the patient's Aadhaar card issued by Unique Identification Authority of India (UIDAI) are used as denture markers. This article describes a simple, quick, and economical method for identification of individual.

Denture identification using unique identification authority of India barcode.

Science.gov (United States)

Mahoorkar, Sudhindra; Jain, Anoop

2013-01-01

Over the years, various denture marking systems have been reported in the literature for personal identification. They have been broadly divided into surface marking and inclusion methods. In this technique, patient's unique identification number and barcode printed in the patient's Aadhaar card issued by Unique Identification Authority of India (UIDAI) are used as denture markers. This article describes a simple, quick, and economical method for identification of individual.

Multi-level Reconfigurable Self-organization in Overlay Services

NARCIS (Netherlands)

Pournaras, E.

2013-01-01

Large-scale decentralized systems organized in overlay networks are complex to manage. Such systems integrate organizational complexity in the application-level resulting in low abstraction and modularity in their services. This thesis introduces a multi-level conceptual architecture for overlay

Strategic intelligence on emerging technologies: Scientometric overlay mapping

NARCIS (Netherlands)

Rotolo, D.; Rafols, I.; Hopkins, M.M.; Leydesdorff, L.

This paper examines the use of scientometric overlay mapping as a tool of “strategic intelligence” to aid the governing of emerging technologies. We develop an integrative synthesis of different overlay mapping techniques and associated perspectives on technological emergence across geographical,

Telescopic Partial Dentures-Concealed Technology.

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Bhagat, Tushar Vitthalrao; Walke, Ashwini Nareshchandra

2015-09-01

The ideal goal of good dentist is to restore the missing part of oral structure, phonetics, his look and the most important is restored the normal health of the patient, which is hampered due to less or insufficient intake of food. Removable partial denture (RPD) treatment option is considered as a notion, which precludes the inevitability of "floating plastic" in edentulous mouth, that many times fail to fulfill the above essential of the patients. In modern dentistry, though the dental implants or fixed partial denture is the better options, but they have certain limitations. However, overdentures and particularly telescopic denture is the overlooked technology in dentistry that would be a boon for such needy patients. Telescopic denture is especially indicated in the distal edentulous area with minimum two teeth bilaterally present with a good amount of periodontal support. This treatment modality is sort of preventive prosthodontics remedy, which in a conservative manner preserve the remaining teeth and helps in conservation of alveolar bone ultimately. There are two tenets related to this option, one is constant conservation edentulous ridge around the retained tooth and the most important is the endless existence of periodontal sensory action that directs and monitor gnathodynamic task. In this option the primary coping or inner coping are cemented on the prepared tooth, and a similar removable outer or inner telescopic crown placed tightly by using a mechanism of tenso-friction, this is firmly attached to a removable RPD in place without moving or rocking of the prosthesis, which is the common compliant of almost all patients of RPD. Copings are also protecting the abutment from tooth decay and also offers stabilization and maintaining of the outer crown. The outer crown engages the inner coping and gives as an anchor for the remainder of the dentition. This work is the review of telescopic prosthesis which is well supported by the case discussion, and

Correlation between factors associated with the removable partial dentures use and Candida spp. in saliva.

Science.gov (United States)

Gusmão, João Milton Rocha; Ferreira dos Santos, Silvana Soleo; Neisser, Maximiliano Piero; Jorge, Antônio Olavo Cardoso; Faria, Ms Ivan

2011-12-01

To correlate the presence and number of Candida spp. in the saliva of wearers of removable partial dentures retained with precision attachments with the proportion of metal/acrylic resin present in the dentures. Saliva samples from 40 removable partial denture wearers (test) and one paired sample of individuals, non-wearers of any type of removable denture (control) were collected, seeded, and the colony forming units of Candida counted and identified. The metal/acrylic resin proportion of each denture was quantified, using silicone plates pressed over each denture. Candida spp. was found in the saliva of 80% of the individuals in the test group and 65% of the control, with C. albicans being the most prevalent species. The test group presented with the highest number of colony forming units of Candida per ml of saliva, and there was weak correlation between this number and the metal and resin area of the denture (Pearson's coefficient of correlation). Greater prevalence and a higher number of colony forming units of Candida per ml of saliva occurred in removable partial denture wearers (p = 0.04) with a weak positive correlation between the metal and resin area and the number of colony forming units of Candida per ml of saliva. However, this correlation was more significant for the area of resin. © 2010 The Gerodontology Society and John Wiley & Sons A/S.

Use of Candida-specific chicken egg yolk antibodies to inhibit the adhering of Candida to denture base materials: prevention of denture stomatitis.

Science.gov (United States)

Kamikawa, Yoshiaki; Fujisaki, Junichi; Nagayama, Tomohiro; Kawasaki, Kiyotsugu; Hirabayashi, Daisuke; Hamada, Tomofumi; Sakamoto, Ryoich; Mukai, Hiroshi; Sugihara, Kazumasa

2016-09-01

Polyclonal anti-Candida chicken egg yolk antibodies (anti-IgY) were used to investigate the prevention of adherence of Candida species to denture base material in vitro. Candida is a potential virulence factor that can cause systemic infection and even death in immunocompromised individuals. Because long-term antifungal treatment may lead to the emergence of drug-resistant strains, it is necessary to develop novel preventive measures and treatments for candidiasis. Three types of chicken egg yolk antibodies were used in this study: non-specific antibody (control IgY), Candida albicans-specific antibody (anti-C.a.IgY) and Candida glabrata-specific antibody (anti-C.g.IgY). A mixture of different dilutions of each antibody with a suspension of Candida species and denture base material was incubated for 3 h, and then the colony-forming units of Candida on the denture base material were counted. Compared with control IgY, anti-C.a.IgY and anti-C.g.IgY significantly inhibited the adherence of C. albicans, but anti-C.a.IgY tended to be more potent than anti-C.g.IgY. The adherence of C. glabrata was also inhibited significantly by anti-C.a.IgY and anti-C.g.IgY with almost equivalent potency, indicating that their actions against C. glabrata were comparable. This study revealed the inhibitory effects of anti-C.a.IgY and anti-C.g.IgY against the adherence of C. albicans and C. glabrata to denture base material. This finding indicates the possibility of a beneficial effect of IgYs for the prevention of denture stomatitis and candidiasis in clinical settings. © 2014 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

A comparative analysis of salivary factors and maxillary denture retention in different arch forms: An in vivo study

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Abhishek Shekhar

2018-01-01

Conclusions: Complete denture acts as a mechanical stimulant thus increasing flow rate and pH immediately after complete denture insertion. Density, total protein, and viscosity of saliva decreased after complete denture insertion which may be due to increase in water content of saliva. The retention of maxillary complete denture does not seem to depend on the rate of change of the salivary factors, before and after complete denture insertion. Total basal surface area and maxillary denture retention values were highest in square arch form and least in tapered arch form.

Evaluation of articulation of Turkish phonemes after removable partial denture application

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Özbeki Murat

2003-01-01

Full Text Available In this study, the adaptation of patients to removable partial dentures was evaluated related to articulation of Turkish phonemes. Articulation of /t,d,n,l,r/, /g,k/, /b,p,m/ and /s,z,Õ,v,f,y,j,h,c/ phonemes were evaluated by three speech pathologists, on records taken from 15 patients before the insertion of a removable partial denture, just after insertion, and one week later. The test consisted of evaluation of phoneme articulation of independent syllables in terms of distortion, omission, substitution, mass effect, hypernasality and hyponasality. Data were evaluated with Cochrane Q, McNemar and Kruskal-Wallis tests. The results showed that for some phonemes, problems in articulation occurred after the insertion of a removable partial denture while for others a significant amelioration was observed after the insertion of a removable partial denture. In general, problems in articulation of evaluated phonemes were resolved after one week of use.

Factors influencing the provision of removable partial dentures by dentists in Ireland.

Science.gov (United States)

Allen, Finbarr

2010-01-01

Factors influencing clinical treatment of partially dentate patients are varied, and there is a need to identify factors influencing success in the provision of removable partial dentures. The aim of this study was to assess the attitudes of general dental practitioners (GDPs) in Ireland towards tooth replacement and use of RPDs, in partially dentate older adults. The sample frame was the Register of Dentists in Ireland; data were also collected from a sample of dentists practising under NHS regulations in Northern Ireland. Validated questionnaires were sent to all dentists on the Register of Dentists in the Republic of Ireland, and dentists working under NHS regulations registered with the Central Services Agency in Northern Ireland. Content of the questionnaire included details of the dentist themselves, their dental practice and the profile of partial denture provision. They were also asked to give their views on factors influencing the success or failure of an RPD, the process of providing RPDs and their attitudes to RPD provision. A total of 1,143 responses were received, a response rate of 45%. A mean number of 61 RPDs per annum were provided, with 75% of dentures provided being acrylic based. Respondents indicate their belief that cobalt-chromium based dentures had a longer prognosis than acrylic dentures, but less than half (46%) claim to design the frameworks themselves. Patients' attitudes are considered influential in the success of RPD provision, and their influence on appearance is considered the most important factor influencing success. The most important factors influencing failure are: the patient not requesting a denture; an RPD restoring unbounded saddles; and, lower RPDs. Although considered important, approximately 60% of the sample do not routinely organise follow-up appointments for patients provided with RPDs. The fee structures in the DTSS and DTBS are considered a barrier to quality in the provision of partial dentures.

Factors influencing the provision of removable partial dentures by dentists in Ireland.

LENUS (Irish Health Repository)

Allen, Finbarr

2011-03-15

Factors influencing clinical treatment of partially dentate patients are varied, and there is a need to identify factors influencing success in the provision of removable partial dentures. The aim of this study was to assess the attitudes of general dental practitioners (GDPs) in Ireland towards tooth replacement and use of RPDs, in partially dentate older adults. The sample frame was the Register of Dentists in Ireland; data were also collected from a sample of dentists practising under NHS regulations in Northern Ireland. Validated questionnaires were sent to all dentists on the Register of Dentists in the Republic of Ireland, and dentists working under NHS regulations registered with the Central Services Agency in Northern Ireland. Content of the questionnaire included details of the dentist themselves, their dental practice and the profile of partial denture provision. They were also asked to give their views on factors influencing the success or failure of an RPD, the process of providing RPDs and their attitudes to RPD provision. A total of 1,143 responses were received, a response rate of 45%. A mean number of 61 RPDs per annum were provided, with 75% of dentures provided being acrylic based. Respondents indicate their belief that cobalt-chromium based dentures had a longer prognosis than acrylic dentures, but less than half (46%) claim to design the frameworks themselves. Patients\\' attitudes are considered influential in the success of RPD provision, and their influence on appearance is considered the most important factor influencing success. The most important factors influencing failure are: the patient not requesting a denture; an RPD restoring unbounded saddles; and, lower RPDs. Although considered important, approximately 60% of the sample do not routinely organise follow-up appointments for patients provided with RPDs. The fee structures in the DTSS and DTBS are considered a barrier to quality in the provision of partial dentures.

Factors influencing the provision of removable partial dentures by dentists in Ireland.

LENUS (Irish Health Repository)

Allen, Finbarr

2010-10-01

Factors influencing clinical treatment of partially dentate patients are varied, and there is a need to identify factors influencing success in the provision of removable partial dentures. The aim of this study was to assess the attitudes of general dental practitioners (GDPs) in Ireland towards tooth replacement and use of RPDs, in partially dentate older adults. The sample frame was the Register of Dentists in Ireland; data were also collected from a sample of dentists practising under NHS regulations in Northern Ireland. Validated questionnaires were sent to all dentists on the Register of Dentists in the Republic of Ireland, and dentists working under NHS regulations registered with the Central Services Agency in Northern Ireland. Content of the questionnaire included details of the dentist themselves, their dental practice and the profile of partial denture provision. They were also asked to give their views on factors influencing the success or failure of an RPD, the process of providing RPDs and their attitudes to RPD provision. A total of 1,143 responses were received, a response rate of 45%. A mean number of 61 RPDs per annum were provided, with 75% of dentures provided being acrylic based. Respondents indicate their belief that cobalt-chromium based dentures had a longer prognosis than acrylic dentures, but less than half (46%) claim to design the frameworks themselves. Patients\\' attitudes are considered influential in the success of RPD provision, and their influence on appearance is considered the most important factor influencing success. The most important factors influencing failure are: the patient not requesting a denture; an RPD restoring unbounded saddles; and, lower RPDs. Although considered important, approximately 60% of the sample do not routinely organise follow-up appointments for patients provided with RPDs. The fee structures in the DTSS and DTBS are considered a barrier to quality in the provision of partial dentures.

RADAR PPI Scope Overlay

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — RADAR PPI Scope Overlays are used to position a RADAR image over a station at the correct resolution. The archive maintains several different RADAR resolution types,...

Exploring overlay journals: the RIOJA project

CERN Multimedia

CERN. Geneva

2007-01-01

Researchers in cosmology and astrophysics depend on the arXiv repository for the registration and dissemination of their work, as well as for current awareness, yet they continue to submit papers to journals for review. Could rapid quality certification be overlaid directly onto the arXiv repository? This presentation introduces the RIOJA (Repository Interface to Overlaid Journal Archives) project, on which a group of cosmology researchers from the UK is working with UCL Library Services and Cornell University. The project is creating a tool to support the overlay of journals onto repositories, and will demonstrate a cosmology journal overlaid on top of arXiv. RIOJA will also work with the cosmology community to explore the social and economic aspects of journal overlay in this discipline: what other value, besides the quality stamp, does journal publication typically add? What are the costs of the ideal overlay journal for this community, and how could those costs be recovered? Would researchers real...

Overlay improvements using a real time machine learning algorithm

Science.gov (United States)

Schmitt-Weaver, Emil; Kubis, Michael; Henke, Wolfgang; Slotboom, Daan; Hoogenboom, Tom; Mulkens, Jan; Coogans, Martyn; ten Berge, Peter; Verkleij, Dick; van de Mast, Frank

2014-04-01

While semiconductor manufacturing is moving towards the 14nm node using immersion lithography, the overlay requirements are tightened to below 5nm. Next to improvements in the immersion scanner platform, enhancements in the overlay optimization and process control are needed to enable these low overlay numbers. Whereas conventional overlay control methods address wafer and lot variation autonomously with wafer pre exposure alignment metrology and post exposure overlay metrology, we see a need to reduce these variations by correlating more of the TWINSCAN system's sensor data directly to the post exposure YieldStar metrology in time. In this paper we will present the results of a study on applying a real time control algorithm based on machine learning technology. Machine learning methods use context and TWINSCAN system sensor data paired with post exposure YieldStar metrology to recognize generic behavior and train the control system to anticipate on this generic behavior. Specific for this study, the data concerns immersion scanner context, sensor data and on-wafer measured overlay data. By making the link between the scanner data and the wafer data we are able to establish a real time relationship. The result is an inline controller that accounts for small changes in scanner hardware performance in time while picking up subtle lot to lot and wafer to wafer deviations introduced by wafer processing.

Photodynamic antimicrobial therapy in the treatment of denture stomatitis

International Nuclear Information System (INIS)

Senna, Andre Machado de

2012-01-01

Denture stomatitis (DS), also called chronic atrophic candidiasis, is the most common oral fungal infection in denture wearers. It has a multifactorial etiology, but the presence of Candida spp. biofilm on the denture is considered the most important factor for the establishment of the DS. This study aimed to evaluate the treatment of DS through the use of photodynamic antimicrobial therapy (PAT), mediated by methylene blue. For this purpose, preclinical studies and clinical trials were performed. Simulators prototypes dentures were made of methyl methacrylate polymer to serve as a basis for biofilm growth of the following species of Candida: C. albicans, C. glabrata, C. dubliniensis, C. krusei, C. tropicalis, C. parapsilosis and C. guilliermondii. Methylene blue solution at a concentration of 450 μg/mL was used as a photosensitizer. The prototypes and biofilms were irradiated with a laser of wavelength of 660 nm, potency of 100 mW, for 80 seconds. For the clinical study, subjects were divided into two groups. The first group received conventional treatment based on the use of antifungal Miconazole. The second group received the treatment by PAT. The preclinical results showed that all species of the genus Candida were susceptible to PAT, with a reduction in colonies that ranged from 2.48 to 3.93 log 10 . Clinical outcomes were evaluated for the reduction of colonies of Candida spp. located in the mucosa and in the prosthesis and relative to the improvement of the clinical aspect of the affected mucosa. Both the conventional therapy and PAT were effective in treating DS. There was no significant statistical difference between PAT and conventional treatment for any of the factors evaluated. Thus, it was concluded that PAT is effective in the treatment of denture stomatitis. (author)

Residual stress reduction in the penetration nozzle weld joint by overlay welding

International Nuclear Information System (INIS)

Jiang, Wenchun; Luo, Yun; Wang, B.Y.; Tu, S.T.; Gong, J.M.

2014-01-01

Highlights: • Residual stress reduction in penetration weld nozzle by overlay welding was studied. • The overlay weld can decrease the residual stress in the weld root. • Long overlay welding is proposed in the actual welding. • Overlay weld to decrease residual stress is more suitable for thin nozzle. - Abstract: Stress corrosion cracking (SCC) in the penetration nozzle weld joint endangers the structural reliability of pressure vessels in nuclear and chemical industries. How to decrease the residual stress is very critical to ensure the structure integrity. In this paper, a new method, which uses overlay welding on the inner surface of nozzle, is proposed to decrease the residual stresses in the penetration joint. Finite element simulation is used to study the change of weld residual stresses before and after overlay welding. It reveals that this method can mainly decrease the residual stress in the weld root. Before overlay welding, large tensile residual stresses are generated in the weld root. After overlay weld, the tensile hoop stress in weld root has been decreased about 45%, and the radial stress has been decreased to compressive stress, which is helpful to decrease the susceptibility to SCC. With the increase of overlay welding length, the residual stress in weld root has been greatly decreased, and thus the long overlay welding is proposed in the actual welding. It also finds that this method is more suitable for thin nozzle rather than thick nozzle

Improving concrete overlay construction.

Science.gov (United States)

2010-03-01

Several road construction projects involving concrete overlays at the state and county levels in Iowa in 2009 were studied for : construction techniques and methods. The projects that were evaluated consisted of sites in four Iowa counties: Osceola, ...

Wafer edge overlay control solution for N7 and beyond

Science.gov (United States)

van Haren, Richard; Calado, Victor; van Dijk, Leon; Hermans, Jan; Kumar, Kaushik; Yamashita, Fumiko

2018-03-01

Historically, the on-product overlay performance close to the wafer edge is lagging with respect to the inner part of the wafer. The reason for this is that wafer processing is less controlled close to the wafer edge as opposed to the rest of the wafer. It is generally accepted that Chemical Vapor Deposition (CVD) of stressed layers that cause wafer warp, wafer table contamination, Chemical Mechanical Polishing (CMP), and Reactive Ion Etch (RIE) may deteriorate the overlay performance and/or registration close to the wafer edge. For the N7 technology node and beyond, it is anticipated that the tight on-product overlay specification is required across the full wafer which includes the edge region. In this work, we highlight one contributor that may negatively impact the on-product overlay performance, namely the etch step. The focus will be mainly on the wafer edge region but the remaining part of the wafer is considered as well. Three use-cases are examined: multiple Litho-Etch steps (LEn), contact hole layer etch, and the copper dual damascene etch. We characterize the etch contribution by considering the overlay measurement after resist development inspect (ADI) and after etch inspect (AEI). We show that the Yieldstar diffraction based overlay (μDBO) measurements can be utilized to characterize the etch contribution to the overlay budget. The effects of target asymmetry as well as overlay shifts are considered and compared with SEM measurements. Based on the results above, we propose a control solution aiming to reduce or even eliminate the delta between ADI and AEI. By doing so, target/mark to device offsets due to etch might be avoided.

A comparative study for plaque removing efficacy between commonly used denture cleansers in India

Directory of Open Access Journals (Sweden)

Bhushan Kumar

2017-01-01

Conclusions: There was no significant difference among action of four denture cleansers used in this study. Thus we can infer that patients can use liquid handwashing soap or commercial products to overcome disadvantages of toothpastes. Recommendation from the results of this study is the use of liquid handwashing soap for cleansing after every meal and soaking of the denture in commercial denture cleanser during the night.

Fundamentals of overlay measurement and inspection using scanning electron-microscope

Science.gov (United States)

Kato, T.; Okagawa, Y.; Inoue, O.; Arai, K.; Yamaguchi, S.

2013-04-01

Scanning electron-microscope (SEM) has been successfully applied to CD measurement as promising tools for qualifying and controlling quality of semiconductor devices in in-line manufacturing process since 1985. Furthermore SEM is proposed to be applied to in-die overlay monitor in the local area which is too small to be measured by optical overlay measurement tools any more, when the overlay control limit is going to be stringent and have un-ignorable dependence on device pattern layout, in-die location, and singular locations in wafer edge, etc. In this paper, we proposed new overlay measurement and inspection system to make an effective use of in-line SEM image, in consideration of trade-off between measurement uncertainty and measurement pattern density in each SEM conditions. In parallel, we make it clear that the best hybrid overlay metrology is in considering each tool's technology portfolio.

[Complete denture occlusion considered from occlusal contacts during mastication].

Science.gov (United States)

Suzuki, Tetsuya

2004-12-01

Few reports describe the functional superiority of full balanced occlusion to that of lingualized occlusion. Recently, a bilateral balanced scheme has been much more generally applied than a unilateral balanced scheme in lingualized occlusion as well as in full balanced occlusion. Occlusal contacts on the non-chewing side occur earlier than on the chewing side;in the order of second molar, first molar, and then premolars. The contact on the balancing side contributes to the prevention of denture dislocation and guidance from eccentric positions to the centric occlusal position during mastication. Therefore, bilateral balanced occlusion was shown to be effective for denture stability during mastication with complete dentures. Today's typical edentulous patients have greater mean age than in the past, and thus are seen with severe alveolar bone resorption, thin mucosa and sometimes abnormalities of the maxillomandibular relation. Their occlusal positions are often unstable and changeable after insertion of complete dentures. Because lingualized occlusion allows for easier accommodation and correction, lingualized occlusion is more suitable for such cases than full balanced occlusion, which requires a strict occlusal relationship. In light of the standard Japanese diet, there is some doubt about why lingualized occlusion might be suitable for Japanese edentulous patients in terms of the sense of mastication. A method of evaluating the sense of mastication needs to be established.

64nm pitch metal1 double patterning metrology: CD and OVL control by SEMCD, image based overlay and diffraction based overlay

Science.gov (United States)

Ducoté, Julien; Dettoni, Florent; Bouyssou, Régis; Le-Gratiet, Bertrand; Carau, Damien; Dezauzier, Christophe

2015-03-01

Patterning process control of advanced nodes has required major changes over the last few years. Process control needs of critical patterning levels since 28nm technology node is extremely aggressive showing that metrology accuracy/sensitivity must be finely tuned. The introduction of pitch splitting (Litho-Etch-Litho-Etch) at 14FDSOInm node requires the development of specific metrologies to adopt advanced process control (for CD, overlay and focus corrections). The pitch splitting process leads to final line CD uniformities that are a combination of the CD uniformities of the two exposures, while the space CD uniformities are depending on both CD and OVL variability. In this paper, investigations of CD and OVL process control of 64nm minimum pitch at Metal1 level of 14FDSOI technology, within the double patterning process flow (Litho, hard mask etch, line etch) are presented. Various measurements with SEMCD tools (Hitachi), and overlay tools (KT for Image Based Overlay - IBO, and ASML for Diffraction Based Overlay - DBO) are compared. Metrology targets are embedded within a block instanced several times within the field to perform intra-field process variations characterizations. Specific SEMCD targets were designed for independent measurement of both line CD (A and B) and space CD (A to B and B to A) for each exposure within a single measurement during the DP flow. Based on those measurements correlation between overlay determined with SEMCD and with standard overlay tools can be evaluated. Such correlation at different steps through the DP flow is investigated regarding the metrology type. Process correction models are evaluated with respect to the measurement type and the intra-field sampling.

Measurement of Mucosal Thickness in Denture-bearing Area of Edentulous Mandible

Directory of Open Access Journals (Sweden)

Jian Dong

2015-01-01

Full Text Available Background: The thickness of the alveolar mucosa influences the probability of the occurrence of denture-induced irritations. Thick denture-supporting tissues offer relief from mucosal tenderness and ulcers; however, the uniformity of the thickness across the entire mandibular alveolar mucosa cannot be accurately determined in edentulous patients. This study aimed to assess the mucosal thickness of the denture-bearing area in the edentulous mandible. Methods: Twenty-seven edentulous patients underwent cone-beam computed tomography scanning, wherein the patients wore a record base to retract soft tissues away from the alveolar mucosa. The measured regions were the central incisor (IC, lateral incisor (IL, canine (Ca, first premolar (P1, second premolar (P2, first molar (M1, and second molar (M2 regions. The thickness was measured in the alveolar ridge crest (T, buccal (B1-B4, and lingual (L1-L4 alveolar ridge mucosa. The average thickness of the mucosa at buccal sides (B and lingual sides (L were also assessed. Results: The differences in the mucosal thickness between the left and right sides were not significant. In the Ca-M2 regions, T was the thickest, and L3 was the thinnest of all the measured points in the same regions. L was significantly less than B in posterior regions (P < 0.01. On the other hand, M2 at L4 was thinnest of all the measured regions from Ca to M2 (P < 0.01, and was thicker than IC, IL, P1, and P2 at B2. Conclusions: Since the mucosal thickness of denture-bearing area in the edentulous mandible is not uniform; the tissue surface of the denture base or custom tray should be selectively relieved, which may reduce the risk of denture-induced irritations.

Detection of improvement in the masticatory function from old to new removable partial dentures using mixing ability test.

Science.gov (United States)

Asakawa, A; Fueki, K; Ohyama, T

2005-09-01

The aim of this study was to determine the sensitivity of the Mixing Ability Test to detect improvement of masticatory function in subjects on transition from old to new removable partial dentures. Thirty-two subjects (seven males, 25 females, mean age 65.0 years) with distal extension partially edentulous area in mandible and/or maxilla participated in the study. The following reasons were presented for replacing the old removable partial dentures with new ones: fracture and/or poor fitness of retainers, extraction of abutment teeth, poor fitness of denture base, severe wear of artificial teeth and request for metal base dentures. Masticatory function with old and new removable partial dentures after an adaptation period (mean 27.4 weeks) was evaluated by the Mixing Ability Test. Subjects were asked to masticate five two-coloured wax cubes with each removable partial denture. Mixing Ability Index was obtained from the colour mixture and shape of the masticated cubes. Wilcoxon signed-rank test was used to test the difference of Mixing Ability Indexes between old and new removable partial dentures. The mixing ability indexes with new removable partial dentures (mean+/- s.d.: 0.70+/- 0.68) was significantly higher (Premovable partial dentures (-0.11+/-1.13). The results suggest that the Mixing Ability Test was capable of detecting improvement in masticatory function with new removable partial dentures.

Pressure distribution of implant-supported removable partial dentures with stress-breaking attachments.

Science.gov (United States)

Kono, Kentaro; Kurihara, Daisuke; Suzuki, Yasunori; Ohkubo, Chikahiro

2014-04-01

This in vitro study investigated the pressure distribution of the implant-supported removable partial dentures (RPDs) with the stress-breaking attachments under the occlusal force. The experimental model of bilateral missing premolars and molars was modified from a commercial simulation model. Five pressure sensors were embedded near the bilateral first molars, first premolars, and medio-lingual alveolar crest. Two implants were placed near the second molars, and they were connected to the denture base using the following conditions: complete separation between the denture base and implant with cover screws (CRPD), flexible connection with a stress-breaking ball (SBB) attachment, and rigid connection without stress breaking with healing caps (HC). The pressure at five different areas of the soft tissue and the displacement of the RPDs were simultaneously measured, loading up to 50 N. The coefficient of variation (CV) for each connection was calculated from all data of the pressure at five areas to evaluate the pressure distribution. The pressure on medio-lingual alveolar crest and molars of the HC was less than SBB and CRPD. In contrast, the pressure on premolars of SBB was greater than for the HC and CRPD. The CV of SBB was less than that of HC and CRPD. Denture displacement of HC and SBB was less than for CRPD. Within the in vitro limitations, precise denture settlements and pressure distribution under the denture base could be controlled using an SBB attachment. An SBB attachment might be able to protect the implant from harmful force. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Usage of removable partial dentures in Saudi male patients after 1 year telephone interview

Science.gov (United States)

Akeel, Riyadh

2010-01-01

Objective The success of removable partial dentures (RPDs) is partly dependent on patients’ acceptance and compliance in using them. The purpose of this study was to describe the usage of removable partial dentures (RPDs) by patients 1 year after insertion and to evaluate the factors that influence their denture usage. Methods Forty-seven patients who received 75 new RPDs at the undergraduate clinic of College of Dentistry, King Saud University, were contacted by telephone 1 year later for an interview. The questions covered denture usage, patient’s satisfaction and reasons for non-use. Results Results showed that 36% of patients discarded or occasionally used their RPDs. There was no significant association between denture usage and RPD experience, location or Kennedy classification. A significantly more RPD rejection was found when it was opposed by natural teeth or complete denture. The most quoted reason for RPD rejection was pain and discomfort. Conclusion Despite the short follow-up period, RPDs were poorly accepted by patients treated by undergraduate students. PMID:23960487

Patient’s Satisfaction with Removable Partial Dentures: A Retrospective Case Series

Science.gov (United States)

Shala, Kujtim Sh.; Dula, Linda J.; Pustina-Krasniqi, Teuta; Bicaj, Teuta; Ahmedi, Enis F.; Lila-Krasniqi, Zana; Tmava-Dragusha, Arlinda

2016-01-01

This retrospective clinical study aimed to assess patient’s satisfaction with removable partial dentures (RPDs), as retention, chewing ability, aesthetics during the observation period. Material and Methods: A total of 63 patients with RPDs, participated in this study. The following data was collected: Kennedy classification, denture design, denture support, satisfaction and success of RPD. Result: The results showed that 73.6% of patients were wearing RPD for the first time and were finally satisfied. According to the denture support of RPDs, clasp-retained quadrangular RPDs were 100% effective, followed by triangular dental support 81% and linear dental support 47.7%. Comparison of RPDs with attachment with RPDs with claps assessed through Fisher exact test, confirmed statistically significant difference (P=0.008), despite retention; however, chewing ability and aesthetics showed no statistically significant difference with X 2 test on patient’s satisfaction with RPD with or without attachment. Conclusion: Patients often would prefer not showing the anterior buccal clasps of RPD, therefore are generally satisfied more with RPD with attachment based on level of retention, chewing ability and aesthetics. PMID:28077970

Electronic structure of uranium overlayers on magnesium and aluminium

Science.gov (United States)

Gouder, T.

1997-06-01

We studied U overlayers on polycrystalline Mg and Al by X-ray and ultra-violet photoelectron spectroscopies (XPS and UPS, respectively), and compared the mode of growth and the evolution of the electronic structure as a function of coverage. The goal of this work was to detect localization, or at least correlation effects, in U overlayers and U substrate near surface alloys, which were expected to occur because of the reduced U 5f bandwidth in these systems. On Mg, U deposits as a pure overlayer without any interdiffusion, while on Al spontaneous interdiffusion takes place. The U 4f spectra of {U}/{Mg} show only weak correlation satellites. Nevertheless, the asymmetrical shape of the U 4f peak indicates 5f band narrowing. On Al, strong correlation satellites are observed in addition to plasmon loss features. It seems that U-substrate interactions promote correlation effects, while the reduced coordination in overlayers plays a less important role. UPS valence-band (VB) spectra of the two systems look remarkably similar. They do not show any correlation satellites. With decreasing overlayer thickness the 5f peak narrows, which is attributed to 5f band narrowing at the surface.

Clinical evaluation of removable partial dentures on the periodontal health of abutment teeth: a retrospective study.

Science.gov (United States)

Dula, Linda J; Ahmedi, Enis F; Lila-Krasniqi, Zana D; Shala, Kujtim Sh

2015-01-01

The aim of this retrospective study was to evaluate the effect of removable partial dentures in periodontal abutment teeth in relation to the type of denture support and design of RPD in a five-year worn period. Methods : A total of 64 patients with removable partial dentures (RPDs), participated in this study. It were examined ninety-one RPDs. There were seventy-five RPDs with clasp-retained and sixteenth were RPDs with attachments. There were 28 females and 36 males, aged between 40-64 years, 41 maxillary and 50 mandible RPDs. For each subjects the following data were collected: denture design, denture support, and Kennedy classification. Abutment teeth were assessed for plaque index (PI), calculus index (CI), blending on probing (BOP), probing depth (PD), gingival recession (GR), tooth mobility (TM). Level of significance was set at pdenture support of RPD, BOP, PD, PI, GR, CI and TM-index showed no statistically significant difference. Based on the denture design of RPD's, BOP, PD, PI, CI, and TM-index proved no statistically significant difference. Except GR-index according to denture design confirmed statistically significant difference in RPD with clasp pdentures and below the clasp arms in abutment teeth.

Prefabricated light-polymerizing plastic pattern for partial denture framework

Directory of Open Access Journals (Sweden)

Atsushi Takaichi

2011-01-01

Full Text Available Our aim is to report an application of a prefabricated light-polymerizing plastic pattern to construction of removable partial denture framework without the use of a refractory cast. A plastic pattern for the lingual bar was adapted on the master cast of a mandibular Kennedy class I partially edentulous patient. The pattern was polymerized in a light chamber. Cobalt-chromium wires were employed to minimize the potential distortion of the plastic framework. The framework was carefully removed from the master cast and invested with phosphate-bonded investment for the subsequent casting procedures. A retentive clasp was constructed using 19-gauge wrought wire and was welded to the framework by means of laser welding machine. An excellent fit of the framework in the patient′s mouth was observed in the try-in and the insertion of the denture. The result suggests that this method minimizes laboratory cost and time for partial denture construction.

[Correlation of psychoemotional status and adaptation to complete dentures].

Science.gov (United States)

Barkan, I Yu; Stafeev, A A; Repin, V S

2015-01-01

Patients with full adentia are characterized by the formation of specific psycho-emotional status. Rational psychotherapeutic support of these patients largely determines the efficiency of dental prosthetic treatment. At the same time, the definition of mental and emotional status is not included in the diagnostic examination protocol. Considering the above the purpose of the study was to evaluate mental and emotional status of patients receiving complete dentures. Prosthetic rehabilitation of 30 patients with complete teeth loss was performed and clinical evaluation and evaluation of mental and emotional status were carried out before and after treatment. Patients with negative experiences of prosthetics showed a higher level of personal and situational anxiety. There was correlation of adaptation to removable dentures and the patient's personality traits. It is determined that emotional instability during treatment tends to decrease affecting the timing of adaptation to complete dentures. It is noted that patients with repeated prosthetics have earlier recovery of coordination ability of the masticatory muscles.

Final-impression techniques and materials for making complete and removable partial dentures.

Science.gov (United States)

Jayaraman, Srinivasan; Singh, Balendra P; Ramanathan, Balasubramanian; Pazhaniappan Pillai, Murukan; MacDonald, Laura; Kirubakaran, Richard

2018-04-04

Endentulism is relatively common and is often treated with the provision of complete or partial removable dentures. Clinicians make final impressions of complete dentures (CD) and removable partial dentures (RPD) using different techniques and materials. Applying the correct impression technique and material, based on an individual's oral condition, improves the quality of the prosthesis, which may improve quality of life. To assess the effects of different final-impression techniques and materials used to make complete dentures, for retention, stability, comfort, and quality of life in completely edentulous people.To assess the effects of different final-impression techniques and materials used to make removable partial dentures, for stability, comfort, overextension, and quality of life in partially edentulous people. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 22 November 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Register of Studies, to 22 November 2017), MEDLINE Ovid (1946 to 22 November 2017), and Embase Ovid (21 December 2015 to 22 November 2017). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on language or publication status when searching the electronic databases, however the search of Embase was restricted by date due to the Cochrane Centralised Search Project to identify all clinical trials and add them to CENTRAL. We included randomised controlled trials (RCTs) comparing different final-impression techniques and materials for treating people with complete dentures (CD) and removable partial dentures (RPD). For CD, we included trials that compared different materials or different techniques or both. In RPD for tooth-supported conditions, we included trials comparing the

High-volume manufacturing device overlay process control

Science.gov (United States)

Lee, Honggoo; Han, Sangjun; Woo, Jaeson; Lee, DongYoung; Song, ChangRock; Heo, Hoyoung; Brinster, Irina; Choi, DongSub; Robinson, John C.

2017-03-01

Overlay control based on DI metrology of optical targets has been the primary basis for run-to-run process control for many years. In previous work we described a scenario where optical overlay metrology is performed on metrology targets on a high frequency basis including every lot (or most lots) at DI. SEM based FI metrology is performed ondevice in-die as-etched on an infrequent basis. Hybrid control schemes of this type have been in use for many process nodes. What is new is the relative size of the NZO as compared to the overlay spec, and the need to find more comprehensive solutions to characterize and control the size and variability of NZO at the 1x nm node: sampling, modeling, temporal frequency and control aspects, as well as trade-offs between SEM throughput and accuracy.

Comparison of changes in vertical dimension of the upper and lower complete dentures processed using two investing methods

International Nuclear Information System (INIS)

Kharat, D.U.; Fakiha, Z.

1990-01-01

Standardized compression molding technique was used to process 14 sets of complete dentures. Seven sets of dentures were invested by the conventional method and the other seven were invested by a modified method. In the latter method, the second layer of the investment extended occlusally only up to the maximum convexity on the labial/buccal and lingual surfaces of the teeth. In the beginning, only the upper or the lower denture was processed and changes in the vertical dimension of occlusion were measured. After that, the other denture was also processed and the increase in the vertical dimension of occlusion of the sets of dentures was measured. All measurements were made at the incisal guide pin using a leaf gauge. Statistical analysis using t-test showed no difference in the changes of vertical dimension of the dentures processed by the two different methods of investing. However, both of the methods of investing showed significantly more increase in vertical dimension of the upper complete dentures than that of the lower complete dentures. (author)

[Resin-bonded fixed partial dentures

NARCIS (Netherlands)

Kreulen, C.M.; Creugers, N.H.J.

2013-01-01

A resin-bonded fixed partial denture is a prosthetic construction which can replace I or several teeth in an occlusal system and which comprises a pontic element which is adhesively attached to 1 or more abutment teeth. To compensate for the limited shear strength of the adhesive layer, the Jixed

21 CFR 872.3450 - Ethylene oxide homopolymer and/or karaya denture adhesive.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ethylene oxide homopolymer and/or karaya denture... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3450 Ethylene oxide homopolymer and/or karaya denture adhesive. (a) Identification. Ethylene oxide homopolymer and/or karaya...

Fracture strength and bending of all-ceramic and fiber-reinforced composites in inlay-retained fixed partial dentures

Directory of Open Access Journals (Sweden)

Serkan Saridag

2012-06-01

Conclusions: Zirconia-based ceramic inlay-retained fixed partial dentures demonstrated the highest fracture strength. The fiber-reinforced composite inlay-retained fixed partial dentures demonstrated higher bending values than did the all-ceramic inlay-retained fixed partial dentures.

Occlusion and Temporomandibular Function among Subjects with Mandibular Distal Extension Removable Partial Dentures.

NARCIS (Netherlands)

Creugers, N.H.J.; Witter, D.J.; Spijker, A. van 't; Gerritsen, A.E.; Kreulen, C.M.

2010-01-01

Objective. To quantify effects on occlusion and temporomandibular function of mandibular distal extension removable partial dentures in shortened dental arches. Methods. Subjects wearing mandibular extension removable partial dentures (n = 25) were compared with subjects with shortened dental arches

Location-Aware Cross-Layer Design Using Overlay Watermarks

Directory of Open Access Journals (Sweden)

Paul Ho

2007-04-01

Full Text Available A new orthogonal frequency division multiplexing (OFDM system embedded with overlay watermarks for location-aware cross-layer design is proposed in this paper. One major advantage of the proposed system is the multiple functionalities the overlay watermark provides, which includes a cross-layer signaling interface, a transceiver identification for position-aware routing, as well as its basic role as a training sequence for channel estimation. Wireless terminals are typically battery powered and have limited wireless communication bandwidth. Therefore, efficient collaborative signal processing algorithms that consume less energy for computation and less bandwidth for communication are needed. Transceiver aware of its location can also improve the routing efficiency by selective flooding or selective forwarding data only in the desired direction, since in most cases the location of a wireless host is unknown. In the proposed OFDM system, location information of a mobile for efficient routing can be easily derived when a unique watermark is associated with each individual transceiver. In addition, cross-layer signaling and other interlayer interactive information can be exchanged with a new data pipe created by modulating the overlay watermarks. We also study the channel estimation and watermark removal techniques at the physical layer for the proposed overlay OFDM. Our channel estimator iteratively estimates the channel impulse response and the combined signal vector from the overlay OFDM signal. Cross-layer design that leads to low-power consumption and more efficient routing is investigated.

Prosthodontic procedures after radiation therapy

International Nuclear Information System (INIS)

Nitta, Eiji; Taniguchi, Hisashi; Uchida, Toshimi; Ohyama, Takashi; Takeda, Masamune

1983-01-01

In two cases, no necrosis of the soft tissues and no osteoradionecrosis occurred. The reason was considered: Lining the denture with soft resin moderated the pressure and impact due to occlusion and movement of artificial teeth. The use of a overlay complete denture helped to avoid mechanical stimulation of attachments to the oral membrane. Simplified design of a denture and survived teeth helped to make dental cleaning easy and to keep good sanitary condition in the mouth. Following application of a denture, convincing guidance to patients were given. Recalls to the hospital with short intervals were effective for preventing erosion, ulceration, and infection. (Ueda, J.)

[Occlusal schemes of complete dentures--a review of the literature].

Science.gov (United States)

Tarazi, E; Ticotsky-Zadok, N

2007-01-01

Occlusal scheme is defined as the form and the arrangement of the occlusal contacts in natural and artificial dentition. The choice of an occlusal scheme will determine the pattern of occlusal contacts between opposing teeth during centric relation and functional movement of the mandible. With dentures, the quantity and the intensity of these contacts determine the amount and the direction of the forces that are transmitted through the bases of the denture to the residual ridges. That is why the occlusal scheme is an important factor in the design of complete dentures. Three occlusal schemes are viewed in this review: bilateral balanced occlusion, monplane occlusion, and linear occlusion scheme. Each scheme represents a different concept of occlusion. Comparisons between these schemes are also reviewed and analyzed. The reasoning underlying the bilateral balanced occlusion scheme is that stability of the dentures is attained when bilateral contacts exist throughout all dynamic and static states of the denture during function. Anatomic teeth are used: the upper anterior teeth are set to satisfy aesthetics, and the posterior teeth are arranged in a compensatory curve and a medial curve. This scheme is adequate for well developed residual ridges, with skeletal class I relation. With highly resorbed residual ridges, the vectors of force that are transmitted through anatomic cusps will dislodge the lower denture and thus impair the comfort and efficiency of mastication experienced by the patient. In order to accommodate to the special needs posed by highly resorbed residual ridges and skeletal relations that are not class I, the monoplane scheme of occlusion was designed. This scheme consists of non anatomic (cuspless) teeth, which are set so that the anterior teeth provide the aesthetics, the premolars and the first molars are used for chewing, and the second molars do not occlude (although sometimes they are specifically used to establish bilateral contacts in lateral

[Selection of occlusal scheme on the basis of pressure distribution on supporting structures under complete dentures].

Science.gov (United States)

Nagao, Kan; Kawano, Fumiaki; Ichikawa, Tetsuo

2004-12-01

In case of making complete dentures, we have to consider not only denture stability but also the restoration of aesthetics and function such as mastication and speech. However these are contradictory theoretically from the point of view of denture stability, and it is very difficult to satisfy both requirements in the case of a patient who has poor upper and lower alveolar ridges. We investigated the effect of artificial posterior teeth form and occlusal scheme on the distribution of pressure on supporting structures under complete dentures during mastication with upper and lower edentulous simulators. In this report, a guideline for the selection of occlusal scheme for complete dentures, based on our previous investigations, is described. The occlusal scheme remarkably affected the distribution of pressure under simulated complete dentures, as shown by comparing the distribution of pressure using two different occlusal schemes:fully balanced occlusion and lingualized occlusion. However other factors such as posterior teeth form and position affect the distribution of pressure as well, and are related to each other. Therefore, not only occlusal scheme but also posterior artificial teeth form has to be considered, and the form of posterior teeth should be carefully and comprehensively decided when making complete dentures.

Analysis of an Orthotropic Deck Stiffened with a Cement-Based Overlay

DEFF Research Database (Denmark)

Walter, Rasmus; Olesen, John Forbes; Stang, Henrik

2007-01-01

decks. A solution might be to enhance the stiffness of the traditional orthotropic bridge deck by using a cement-based overlay. In this paper, an orthotropic steel bridge deck stiffened with a cement-based overlay is analyzed. The analysis is based on nonlinear fracture mechanics, and utilizes......Over the past years, with increasing traffic volumes and higher wheel loads, fatigue damage in steel parts of typical orthotropic steel bridge decks has been experienced on heavily trafficked routes. A demand exists to find a durable system to increase the fatigue safety of orthotropic steel bridge...... the finite-element method. The stiffness of the steel deck reinforced with an overlay depends highly on the composite action. The composite action is closely related to cracking of the overlay and interfacial cracking between the overlay and underlying steel plate (debonding). As an example, a real size...

[Elderly people and removable partial dentures

NARCIS (Netherlands)

Baat, C. de

2009-01-01

The most frequently reported disadvantages of removable partial dentures are the more demanding daily oral hygiene self-care, especially for people who already experience difficulties in self-care, and the possible harmful influence on the remaining dentition. These disadvantages can be expressed in

Nanoindentation and surface roughness profilometry of poly methyl methacrylate denture base materials.

Science.gov (United States)

Zafar, Muhammad Sohail; Ahmed, Naseer

2014-01-01

Polymers have a wide range of applications in dentistry. Poly methyl methacrylate (PMMA) is the most popular for making orthodontic retainers, dentures as well as synthetic teeth. Prior to clinical applications, the appliances are polished in the dental laboratory to achieve smooth, polished and comfortable surfaces. The objective of this study was to analyze the surface roughness profiles of PMMA dentures polished using two different approaches. In addition, the effects of ultrasonication and sandblasting were also evaluated on the fitting surface of PMMA dentures. This was an in vitro study using non-contact mode surface roughness profilometer and nano-indenter. Samples were polished using two different techniques (Standard and modified). Both cold cure and heat cure PMMA denture surfaces were evaluated for roughness, nanohardness and elastic modulus. The absolute hardness was recorded 297.72±19.04 MPa and 229.93±18.53 MPa for heat cured PMMA and cold cured PMMA. Manufactured acrylic teeth were harder (319.20±12.58 MPa) with an elastic modulus of (4.34±1.86 GPa). Modified polishing techniques (group 3) produced smoother surface. It was concluded that elastic moduli of acrylic tooth and heat cure PMMA is not very different. Surface treatments such as ultrasonication or sandblasting do not affect the roughness profiles of denture fitting surfaces.

Implant overdentures: dental students' performance in fabrication, denture quality, and patient satisfaction.

Science.gov (United States)

Aragon, Cecilia E; Cornacchio, Angelica Lee Petrina; Ibarra, Lilia Marcela; Saad, Muhammed N; Zibrowski, Elaine

2010-09-01

The purpose of this study was to evaluate dental students' performance when fabricating a mandibular two-implant overdenture (OD) as compared to conventional dentures (CD) and to determine if these prostheses were successful. Twenty students and twenty patients were divided into two groups: complete denture group (CDG) and maxillary denture and two-implant OD group (ODG). Students' progress was evaluated at each appointment as they were given a clinical assessment score (CAS), which varied from 1 (unacceptable, needs to repeat procedure) to 4 (acceptable, no errors). The success of the prosthesis was evaluated by the patients using a visual analog scale (VAS) and an expert (a prosthodontist) using a denture quality assessment (DQA) form. Performance for both groups was not statistically different across all eight appointments (CDG 3.16 versus ODG 3.25; p=0.46). Patients with ODs reported greater stability with their dentures (p=0.048) and greater ability to chew than patients with CDs (p=0.03). There were no differences between the groups in terms of expert appraisal (ODG 71.1 versus CDG 67.5; p=0.59). The performance of dental students when fabricating a two-implant OD is thus not different from that of a CD. Students can successfully fabricate a two-implant OD as perceived by both patients and prosthodontists.

The Role of New Removable Complete Dentures in Stimulated Salivary Flow and Taste Perception.

Science.gov (United States)

Tango, Rubens Nisie; Arata, Anelyse; Borges, Alexandre Luiz Souto; Costa, Anna K F; Pereira, Luciano Jose; Kaminagakura, Estela

2018-04-01

To evaluate the effect of replacement of inadequate complete dentures on salivary flow and taste perception in geriatric patients. Thirty-three patients, 13 males and 20 females, with a mean age of 64.4 years were submitted to stimulated and unstimulated salivary flow rate and salivary pH measurements, and sense of taste evaluation. Tests were performed 3 months before complete denture substitution and 3 weeks after denture insertion. The mean for unstimulated saliva (USS) was 2.1 ml before and 2.7 ml after replacement (p = 0.003). The mean volume of stimulated saliva was 6.3 ml before and 8.2 ml after replacement (p = 0.004). The pH mean of USS was 7.8 ± 0.44 before and 8.02 ± 0.41 after replacement (p = 0.005). No statistically significant difference was determined in the sense of taste before and 3 weeks after complete denture replacement. The replacement of inadequate complete dentures increases saliva flow; however, it does not improve taste perception. © 2016 by the American College of Prosthodontists.

Virtual overlay metrology for fault detection supported with integrated metrology and machine learning

Science.gov (United States)

Lee, Hong-Goo; Schmitt-Weaver, Emil; Kim, Min-Suk; Han, Sang-Jun; Kim, Myoung-Soo; Kwon, Won-Taik; Park, Sung-Ki; Ryan, Kevin; Theeuwes, Thomas; Sun, Kyu-Tae; Lim, Young-Wan; Slotboom, Daan; Kubis, Michael; Staecker, Jens

2015-03-01

While semiconductor manufacturing moves toward the 7nm node for logic and 15nm node for memory, an increased emphasis has been placed on reducing the influence known contributors have toward the on product overlay budget. With a machine learning technique known as function approximation, we use a neural network to gain insight to how known contributors, such as those collected with scanner metrology, influence the on product overlay budget. The result is a sufficiently trained function that can approximate overlay for all wafers exposed with the lithography system. As a real world application, inline metrology can be used to measure overlay for a few wafers while using the trained function to approximate overlay vector maps for the entire lot of wafers. With the approximated overlay vector maps for all wafers coming off the track, a process engineer can redirect wafers or lots with overlay signatures outside the standard population to offline metrology for excursion validation. With this added flexibility, engineers will be given more opportunities to catch wafers that need to be reworked, resulting in improved yield. The quality of the derived corrections from measured overlay metrology feedback can be improved using the approximated overlay to trigger, which wafers should or shouldn't be, measured inline. As a development or integration engineer the approximated overlay can be used to gain insight into lots and wafers used for design of experiments (DOE) troubleshooting. In this paper we will present the results of a case study that follows the machine learning function approximation approach to data analysis, with production overlay measured on an inline metrology system at SK hynix.

[Effects of removable partial dentures on the quality of life in people with shortened dental arches].

Science.gov (United States)

Armellini, D B; Heydecke, G; Witter, D J; Creugers, N H J

2009-12-01

In order to assess the enhanced value of removable partial dentures on the quality of life, patients at 2 university clinics were screened for the presence of complete or shortened dental arches. Those selected were assigned to 1 of 5 subgroups: 1) a shortened dental arch with all frontal teeth, 2) a shortened dental arch with one or more frontal diastemas, 3) a shortened dental arch with all frontal teeth, restored by a removable partial denture, 4) a shortened dental arch and several diastemas, restored by a removable partial denture, 5) a complete dental arch. The participants completed the Oral Health Impact Profile (OHIP-49) and the Short Form Health Survey (SF-36). Clinical data recorded were: whether any teeth were missing and if so which, whether or not these had been replaced by a removable partial denture, and the number of occluding pairs of (pre)molars. The results revealed that a shortenend dental arch has a certain impact on the quality of life. However, the participants only experienced benefits from a removable partial denture if the denture also replaced frontal teeth.

Plastic collapse moment for pipe repaired with weld overlay

International Nuclear Information System (INIS)

Li, Yinsheng; Hasegawa, Kunio; Shibuya, Akira; Deardorff, Arthur

2009-01-01

The Weld Overlay has been used in several countries as an effective method to repair the stress corrosion cracks in nuclear power plant piping. However, the method to evaluate the plastic collapse stress for the pipe repaired with Weld Overlay has not been proposed and the limit load criterion for single uniform material has been used to design its structure by now. In this paper, the equations to evaluate the plastic collapse moment for the pipe repaired with Weld Overlay have been derived considering two layer materials. Moreover, several numerical examples are given to show the validity of Weld Overlay. The equations given in this paper are simple to use like the limit load criterion showed in present standards such as JSME Rules on Fitness-for-Service for Nuclear Power Plants or ASME Boiler and Pressure Vessel Code Section XI, and they can not only be used to evaluate the fracture of the pipe, but also be applied to design the weld structure. (author)

21 CFR 872.3410 - Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ethylene oxide homopolymer and/or....3410 Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive. (a) Identification. An ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive is a device...

Application of Interfacial Propagation and Kinking Crack Concept to ECC/Concrete Overlay Repair System

Directory of Open Access Journals (Sweden)

Yaw ChiaHwan

2014-01-01

Full Text Available Research on the application of ultraductile engineered cementitious composite (ECC as overlay in the repair of deteriorated concrete structures is performed in this paper. Also, interfacial crack kinking and trapping mechanism experimentally observed in ECC/concrete overlay repair system are described by comparison of toughness and energy release rate. The mechanism involves cycles of extension, kinking, and arrest of interfacial crack into the overlay. Experimental testing of overlay repair system reveals significant improvements in load carrying capacity and ductility over conventional concrete overlay. The commonly observed overlay system failure mode of delamination or spalling is eliminated when ECC is applied. These failure modes are suppressed when ECC is used as an ideal and durable candidate overlay repair material.

Complete Denture Impression Techniques Practiced by Private Dental Practitioners: A Survey

OpenAIRE

Kakatkar, Vinay R.

2012-01-01

Impression making is an important step in fabricating complete dentures. A survey to know the materials used and techniques practiced while recording complete denture impressions was conducted. It is disheartening to know that 33 % practitioners still use base plate custom trays to record final impressions. 8 % still use alginate for making final impressions. An acceptable technique for recording CD impressions is suggested.

The influence of polishing techniques on pre-polymerized CAD\\CAM acrylic resin denture bases.

Science.gov (United States)

Alammari, Manal Rahma

2017-10-01

Lately, computer-aided design and computer-aided manufacturing (CAD/CAM) has broadly been successfully employed in dentistry. The CAD/CAM systems have recently become commercially available for fabrication of complete dentures, and are considered as an alternative technique to conventionally processed acrylic resin bases. However, they have not yet been fully investigated. The purpose of this study was to inspect the effects of mechanical polishing and chemical polishing on the surface roughness (Ra) and contact angle (wettability) of heat-cured, auto-cured and CAD/CAM denture base acrylic resins. This study was conducted at the Advanced Dental Research Laboratory Center of King Abdulaziz University from March to June 2017. Three denture base materials were selected: heat cure poly-methylmethacrylate resin, thermoplastic (polyamide resin) and (CAD\\CAM) denture base resin. Sixty specimens were prepared and divided into three groups, twenty in each. Each group was divided according to the polishing techniques into (Mech P) and (Chem P), ten specimens in each; surface roughness and wettability were investigated. Data were analyzed by SPSS version 22, using one-way ANOVA and Pearson coefficient. One-way analysis of variance (ANOVA) and post hoc tests were used for comparing the surface roughness values between three groups which revealed a statistical significant difference between them (p 1 CAD\\CAM denture base material (group III) showed the least mean values (1.08±0.23, 1.39±0.31, Mech P and Chem P respectively). CAD/CAM showed the least contact angle in both polishing methods, which were statistically significant at 5% level (p=0.034 and pCAD\\CAM denture base resin with superior smooth surface compared to chemical polishing. Mechanical polishing is considered the best effective polishing technique. CAD/CAM denture base material should be considered as the material of choice for complete denture construction in the near future, especially for older dental

Occlusal designs on masticatory ability and patient satisfaction with complete denture: a systematic review.

Science.gov (United States)

Zhao, Ke; Mai, Qing-Qing; Wang, Xiao-Dong; Yang, Wen; Zhao, Li

2013-11-01

To systematically review clinical outcomes of different occlusal designs of complete dentures. Using a various key words, an electronic search of clinical trials published in English and Chinese literature was performed from four databases: Medline/PubMed, EMBASE, Cochrane Library, and CBM. Furthermore, a manual searching of the relevant journals and the bibliographies of reviews was performed. General satisfaction, masticatory ability, retention, and stability were major criteria for the evaluation of the outcomes. Studies met these criteria were selected for a full-text reading. The whole processes were performed by two reviewers independently. This systematic review started with 1030 articles, which were finally narrowed down to seven, according to the inclusion criteria. The following occlusal designs were included and analyzed: anatomic occlusion, balanced occlusion, canine guidance occlusion, lingualized occlusion, monoplane occlusion, and bilateral-balanced and canine-guided design. Three of the seven studies showed that lingualized occlusion had ratings of higher patients' satisfaction than other occlusion designs. On the other hand, the canine-guided occlusion dentures demonstrated equal or better clinical performances than bilateral-balanced dentures. Because of the heterogeneity and bias of the studies, it was not possible to analyze the data statistically. Lingualized occlusion and canine-guided occlusion can be successfully applied in the fabrication of complete dentures. Canine guided occlusion has also been shown to be satisfactory. More well-controlled randomized trials are needed regarding canine-guided occlusion and the relationship between alveolar ridge resorption, different occlusal schemes and patient satisfaction. The conventional prosthodontic wisdom that complete dentures require a balanced occlusal design is not supported by the included literature. A suitable occlusal scheme would be a critical factor for a successful complete denture

Kinematics modeling and experimentation of the multi-manipulator tooth-arrangement robot for full denture manufacturing.

Science.gov (United States)

Zhang, Yong-de; Jiang, Jin-gang; Liang, Ting; Hu, Wei-ping

2011-12-01

Artificial teeth are very complicated in shape, and not easy to be grasped and manipulated accurately by a single robot. The method of tooth-arrangement by multi-manipulator for complete denture manufacturing proposed in this paper. A novel complete denture manufacturing mechanism is designed based on multi-manipulator and dental arch generator. Kinematics model of the multi-manipulator tooth-arrangement robot is built by analytical method based on tooth-arrangement principle for full denture. Preliminary experiments on tooth-arrangement are performed using the multi-manipulator tooth-arrangement robot prototype system. The multi-manipulator tooth-arrangement robot prototype system can automatically design and manufacture a set of complete denture that is suitable for a patient according to the jaw arch parameters. The experimental results verified the validity of kinematics model of the multi-manipulator tooth-arrangement robot and the feasibility of the manufacture strategy of complete denture fulfilled by multi-manipulator tooth-arrangement robot.

Assessment and prediction of drying shrinkage cracking in bonded mortar overlays

Energy Technology Data Exchange (ETDEWEB)

Beushausen, Hans, E-mail: hans.beushausen@uct.ac.za; Chilwesa, Masuzyo

2013-11-15

Restrained drying shrinkage cracking was investigated on composite beams consisting of substrate concrete and bonded mortar overlays, and compared to the performance of the same mortars when subjected to the ring test. Stress development and cracking in the composite specimens were analytically modeled and predicted based on the measurement of relevant time-dependent material properties such as drying shrinkage, elastic modulus, tensile relaxation and tensile strength. Overlay cracking in the composite beams could be very well predicted with the analytical model. The ring test provided a useful qualitative comparison of the cracking performance of the mortars. The duration of curing was found to only have a minor influence on crack development. This was ascribed to the fact that prolonged curing has a beneficial effect on tensile strength at the onset of stress development, but is in the same time not beneficial to the values of tensile relaxation and elastic modulus. -- Highlights: •Parameter study on material characteristics influencing overlay cracking. •Analytical model gives good quantitative indication of overlay cracking. •Ring test presents good qualitative indication of overlay cracking. •Curing duration has little effect on overlay cracking.

Assessment and prediction of drying shrinkage cracking in bonded mortar overlays

International Nuclear Information System (INIS)

Beushausen, Hans; Chilwesa, Masuzyo

2013-01-01

Restrained drying shrinkage cracking was investigated on composite beams consisting of substrate concrete and bonded mortar overlays, and compared to the performance of the same mortars when subjected to the ring test. Stress development and cracking in the composite specimens were analytically modeled and predicted based on the measurement of relevant time-dependent material properties such as drying shrinkage, elastic modulus, tensile relaxation and tensile strength. Overlay cracking in the composite beams could be very well predicted with the analytical model. The ring test provided a useful qualitative comparison of the cracking performance of the mortars. The duration of curing was found to only have a minor influence on crack development. This was ascribed to the fact that prolonged curing has a beneficial effect on tensile strength at the onset of stress development, but is in the same time not beneficial to the values of tensile relaxation and elastic modulus. -- Highlights: •Parameter study on material characteristics influencing overlay cracking. •Analytical model gives good quantitative indication of overlay cracking. •Ring test presents good qualitative indication of overlay cracking. •Curing duration has little effect on overlay cracking

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

Science.gov (United States)

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

2008-01-01

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

Effect of three investing materials on tooth movement during flasking procedure for complete denture construction.

Science.gov (United States)

Salloum, Alaa'a M

2016-01-01

Tooth movement has been shown to occur during and after the processing of complete dentures. An understanding of this phenomenon may permit one to construct functional complete dentures that require less occlusal adjustment in the articulator and in the patient's mouth. The purpose of this study was to examine the effects of three different investing methods on tooth movement occurring during the processing of simulated maxillary complete dentures. Forty-five similar maxillary dentures were made using heat-polymerized acrylic resin, and assigned randomly to three experimental groups (n = 15 each) according to investing method: plaster-plaster-plaster (P-P-P), plaster-stone-stone (P-S-S), and plaster-mix (P-M). Specimens in all experimental groups were compression molded with denture base resin. Transverse interincisor (I-I) and intermolar (M-M) distances, and anteroposterior incisor-molar (LI-LM and RI-RM) distances, were measured with digital calipers at the wax denture stage (pre-polymerization) and after denture decasting (post-polymerization). Analysis of variance and Tukey's test were used to compare the results. M-M, LI-LM, and RI-RM movement was significantly greater in the P-P-P group than in the P-S-S and P-M groups; no significant difference in I-I movement was observed among groups. Transverse movement along M-M and I-I was significantly greater than anteroposterior movement in the P-P-P group; no significant difference among measurements was observed in the other two groups. The study results indicate that the use of dental stone or a 50:50 mixture of plaster and stone for investing of dentures is an important factor in efforts to control the magnitude of tooth movement.

The lingualized occlusion of complete denture

Institute of Scientific and Technical Information of China (English)

BEN Wei-hong; Eleni Roumanas

2008-01-01

This article reviews the literatures dealing with the lingualized occlusion of complete denture including the origin,development and research. Lingualized occlusion is a valuable concept because many advantages of anatomic and nonanatomic occlusions are retained,satisfactory occlusion is easily obtained,balanced occlusion can be accomplished.

On Adding Structure to Unstructured Overlay Networks

Science.gov (United States)

Leitão, João; Carvalho, Nuno A.; Pereira, José; Oliveira, Rui; Rodrigues, Luís

Unstructured peer-to-peer overlay networks are very resilient to churn and topology changes, while requiring little maintenance cost. Therefore, they are an infrastructure to build highly scalable large-scale services in dynamic networks. Typically, the overlay topology is defined by a peer sampling service that aims at maintaining, in each process, a random partial view of peers in the system. The resulting random unstructured topology is suboptimal when a specific performance metric is considered. On the other hand, structured approaches (for instance, a spanning tree) may optimize a given target performance metric but are highly fragile. In fact, the cost for maintaining structures with strong constraints may easily become prohibitive in highly dynamic networks. This chapter discusses different techniques that aim at combining the advantages of unstructured and structured networks. Namely we focus on two distinct approaches, one based on optimizing the overlay and another based on optimizing the gossip mechanism itself.

Development of new engine bearings with overlay consisting of solid lubricants; Kotai junkatsu overlay tsuki engine yo suberi jikuuke zairyo no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Kanayama, H; Kawakami, S; Gohara, C [Taiho Kogyo Co. Ltd., Aichi (Japan); Fuwa, Y; Michioka, H [Toyota Motor Corp., Aichi (Japan)

1997-10-01

Recently, modern engines have a tendency for higher output and longer periods. As a result , higher bearing performance is required. For this reason, we have developed the new conceptual overlay consisting of solid lubricants and thermosetting plastics. This paper describes the performance of engine bearings with the new overlay. 5 refs., 13 figs., 5 tabs.

Computer vision and soft computing for automatic skull-face overlay in craniofacial superimposition.

Science.gov (United States)

Campomanes-Álvarez, B Rosario; Ibáñez, O; Navarro, F; Alemán, I; Botella, M; Damas, S; Cordón, O

2014-12-01

Craniofacial superimposition can provide evidence to support that some human skeletal remains belong or not to a missing person. It involves the process of overlaying a skull with a number of ante mortem images of an individual and the analysis of their morphological correspondence. Within the craniofacial superimposition process, the skull-face overlay stage just focuses on achieving the best possible overlay of the skull and a single ante mortem image of the suspect. Although craniofacial superimposition has been in use for over a century, skull-face overlay is still applied by means of a trial-and-error approach without an automatic method. Practitioners finish the process once they consider that a good enough overlay has been attained. Hence, skull-face overlay is a very challenging, subjective, error prone, and time consuming part of the whole process. Though the numerical assessment of the method quality has not been achieved yet, computer vision and soft computing arise as powerful tools to automate it, dramatically reducing the time taken by the expert and obtaining an unbiased overlay result. In this manuscript, we justify and analyze the use of these techniques to properly model the skull-face overlay problem. We also present the automatic technical procedure we have developed using these computational methods and show the four overlays obtained in two craniofacial superimposition cases. This automatic procedure can be thus considered as a tool to aid forensic anthropologists to develop the skull-face overlay, automating and avoiding subjectivity of the most tedious task within craniofacial superimposition. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Achieving optimum diffraction based overlay performance

Science.gov (United States)

Leray, Philippe; Laidler, David; Cheng, Shaunee; Coogans, Martyn; Fuchs, Andreas; Ponomarenko, Mariya; van der Schaar, Maurits; Vanoppen, Peter

2010-03-01

Diffraction Based Overlay (DBO) metrology has been shown to have significantly reduced Total Measurement Uncertainty (TMU) compared to Image Based Overlay (IBO), primarily due to having no measurable Tool Induced Shift (TIS). However, the advantages of having no measurable TIS can be outweighed by increased susceptibility to WIS (Wafer Induced Shift) caused by target damage, process non-uniformities and variations. The path to optimum DBO performance lies in having well characterized metrology targets, which are insensitive to process non-uniformities and variations, in combination with optimized recipes which take advantage of advanced DBO designs. In this work we examine the impact of different degrees of process non-uniformity and target damage on DBO measurement gratings and study their impact on overlay measurement accuracy and precision. Multiple wavelength and dual polarization scatterometry are used to characterize the DBO design performance over the range of process variation. In conclusion, we describe the robustness of DBO metrology to target damage and show how to exploit the measurement capability of a multiple wavelength, dual polarization scatterometry tool to ensure the required measurement accuracy for current and future technology nodes.

Alkaline Peroxides Versus Sodium Hypochlorite for Removing Denture Biofilm: a Crossover Randomized Trial.

Science.gov (United States)

Peracini, Amanda; Regis, Rômulo Rocha; Souza, Raphael Freitas de; Pagnano, Valéria Oliveira; Silva, Cláudia Helena Lovato da; Paranhos, Helena de Freitas Oliveira

2016-01-01

This study evaluated the efficacy of cleanser solutions on denture biofilm removal by a crossover randomized clinical trial. Thirty two edentulous patients were instructed to brush their dentures (specific brush and liquid soap) three times a day (after breakfast, lunch and dinner) and to soak them (≥ 8 h) in: (C) control -water; (AP): alkaline peroxide; or (SH) 0.5% sodium hypochlorite. Each solution was used for 21 days (three cycles of 7 days). At the end of each cycle, the inner surfaces of maxillary dentures were disclosed (1% neutral red) and photographed (HX1 - Sony). Areas (total and stained biofilm) were measured (Image Tool software) and the percentage of biofilm calculated as the ratio between the area of the biofilm multiplied by 100 and total surface area of the internal base of the denture. Data were compared by means of generalized estimating equation (α=5%) and multiple comparisons (Bonferroni; α=1.67%). Immersion in SH reduced biofilm (%) (8.3 ± 13.3B) compared to C (18.2 ± 14.9A) and AP (18.2 ± 16.6A). The 0.5% sodium hypochlorite solution was the most efficacious for biofilm removal. Alkaline peroxides may not lead to further biofilm removal in patients with adequate denture maintenance habits.

Influence of balanced occlusion in complete dentures on the decrease in reduction of an edentulous ridge

Directory of Open Access Journals (Sweden)

Poštić Srđan D.

2012-01-01

Full Text Available Background/Aim. Balanced occlusal arrangement of artificial teeth and balanced occlusion is a specific type of occlusion that preserves the stability of complete dentures. Balanced occlusion comprises realization of tooth contacts at the working side as well as at the balancing side, at the same time. The aim of this study was to assess the influence of balanced occlusal arrangement of artificial teeth on the decrease in reduction of edentulous alveolar ridge. Methods. A longitudinal study on 91 fully edentulous patients was conducted using their panoramic radiographs and parameters of vertical dimension of edentulous ridges. All the patients were clinically examined by the same and a qualified dental practitioner. Numerical values of parameters of vertical dimensions of edentulous ridges and lines were statistically processed and compared using the Student’s t-test. Results. Vertical dimensions and heights of edentulous ridges were different after comparison of parameters in complete denture wearers with balanced occlusion and complete denture wearers without bilaterally balanced occlusion, as well as between male and female edentulous patients. Statistically significant differences of heights were established in complete denture wearers’ with a set of artificial teeth without balanced occlusion, at the baseline and 12 months after wearing of complete dentures. Conclusion. Balanced occlusion is a favored occlusal design in setting of artificial teeth in conventional complete dentures, which preserves edentulous ridge and influence the stability of dentures.

Multicentre prospective evaluation of implant-assisted mandibular bilateral distal extension removable partial dentures: patient satisfaction.

Science.gov (United States)

Wismeijer, Daniel; Tawse-Smith, Andrew; Payne, Alan G T

2013-01-01

To compare the levels of patient satisfaction with either conventional mandibular bilateral distal extension partial dentures or those assisted by bilateral distal implants. Forty-eight participants who were dissatisfied with their existing conventional mandibular distal extension dentures opposing complete maxillary dentures were selected for a multicentre prospective study in New Zealand, Colombia and the Netherlands. A control group of 12 participants in New Zealand received conventional mandibular partial dentures. Three test groups involving 36 participants in New Zealand (12), Colombia (12) and the Netherlands (12) received bilateral distal implants in the second molar regions. After conventional loading, the test group participants initially had healing caps placed on the distal implants providing support only, followed after approximately 6 months by ball abutments (retentive anchors) for support and retention. Patient outcomes were determined with questionnaires completed at specific stages of the study for up to 3 years. Visual analogue scale, Likert and oral health impact questionnaires before and after treatment indicated improved results. There were significantly improved parameters of overall satisfaction, stability, chewing and appearance after 3 years (P removable partial dentures are a preferable treatment option for patients with complaints about their conventional distal extension partial dentures. © 2011 John Wiley & Sons A/S.

KML Super Overlay to WMS Translator

Science.gov (United States)

Plesea, Lucian

2007-01-01

This translator is a server-based application that automatically generates KML super overlay configuration files required by Google Earth for map data access via the Open Geospatial Consortium WMS (Web Map Service) standard. The translator uses a set of URL parameters that mirror the WMS parameters as much as possible, and it also can generate a super overlay subdivision of any given area that is only loaded when needed, enabling very large areas of coverage at very high resolutions. It can make almost any dataset available as a WMS service visible and usable in any KML application, without the need to reformat the data.

Effect of surface treatments on the bond strength of soft denture lining materials to an acrylic resin denture base.

Science.gov (United States)

Gundogdu, Mustafa; Yesil Duymus, Zeynep; Alkurt, Murat

2014-10-01

Adhesive failure between acrylic resin and resilient liner material is commonly encountered in clinical practice. The purpose of this study was to evaluate the effect of different surface treatments on the bond strength of 2 different resilient lining materials to an acrylic resin denture base. Ninety-six dumbbell-shaped specimens were fabricated from heat-polymerized acrylic resin, and 3 mm of the material was cut from the thin midsection. The specimens were divided into 6 groups according to their surface treatments: no surface treatment (control group), 36% phosphoric acid etching (acid group), erbium:yttrium-aluminum-garnet (Er:YAG) laser (laser group), airborne-particle abrasion with 50-μm Al2O3 particles (abrasion group), an acid+laser group, and an abrasion+laser group. The specimens in each group were divided into 2 subgroups according to the resilient lining material used: heat-polymerized silicone based resilient liner (Molloplast B) and autopolymerized silicone-based resilient liner (Ufi Gel P). After all of the specimens had been polymerized, they were stored in distilled water at 37°C for 1 week. A tensile bond strength test was then performed. Data were analyzed with a 2-way ANOVA, and the Sidak multiple comparison test was used to identify significant differences (α=.05). The effects of the surface treatments and resilient lining materials on the surface of the denture base resin were examined with scanning electron microscopy. The tensile bond strength was significantly different between Molloplast B and Ufi Gel P (P<.001). The specimens of the acid group had the highest tensile bond strength, whereas those of the abrasion group had the lowest tensile bond strength. The scanning electron microscopy observations showed that the application of surface treatments modified the surface of the denture base resin. Molloplast B exhibited significantly higher bond strength than Ufi Gel P. Altering the surface of the acrylic resin denture base with 36

Longer Lasting Bridge Deck Overlays

Science.gov (United States)

2018-04-01

The objective of this report is to determine the most effective method for bridge deck overlay construction and repair by assessing current practices; examining new products and technologies; and reviewing NCHRP (National Cooperative Highway Research...

Characterization and bacterial anti-adherent effect on modified PMMA denture acrylic resin containing platinum nanoparticles

OpenAIRE

Nam, Ki-Young

2014-01-01

PURPOSE This study characterized the synthesis of a modified PMMA (Polymethyl methacrylate) denture acrylic loading platinum nanoparticles (PtN) and assessed its bacterial inhibitory efficacy to produce novel antimicrobial denture base material. MATERIALS AND METHODS Polymerized PMMA denture acrylic disc (20 mm × 2 mm) specimens containing 0 (control), 10, 50, 100 and 200 mg/L of PtN were fabricated respectively. The obtained platinum-PMMA nanocomposite (PtNC) was characterized by TEM (transm...

Diffraction-based overlay measurement on dedicated mark using rigorous modeling method

Science.gov (United States)

Lu, Hailiang; Wang, Fan; Zhang, Qingyun; Chen, Yonghui; Zhou, Chang

2012-03-01

Diffraction Based Overlay (DBO) is widely evaluated by numerous authors, results show DBO can provide better performance than Imaging Based Overlay (IBO). However, DBO has its own problems. As well known, Modeling based DBO (mDBO) faces challenges of low measurement sensitivity and crosstalk between various structure parameters, which may result in poor accuracy and precision. Meanwhile, main obstacle encountered by empirical DBO (eDBO) is that a few pads must be employed to gain sufficient information on overlay-induced diffraction signature variations, which consumes more wafer space and costs more measuring time. Also, eDBO may suffer from mark profile asymmetry caused by processes. In this paper, we propose an alternative DBO technology that employs a dedicated overlay mark and takes a rigorous modeling approach. This technology needs only two or three pads for each direction, which is economic and time saving. While overlay measurement error induced by mark profile asymmetry being reduced, this technology is expected to be as accurate and precise as scatterometry technologies.

Pressure transmission area and maximum pressure transmission of different thermoplastic resin denture base materials under impact load.

Science.gov (United States)

Nasution, Hubban; Kamonkhantikul, Krid; Arksornnukit, Mansuang; Takahashi, Hidekazu

2018-01-01

The purposes of the present study were to examine the pressure transmission area and maximum pressure transmission of thermoplastic resin denture base materials under an impact load, and to evaluate the modulus of elasticity and nanohardness of thermoplastic resin denture base. Three injection-molded thermoplastic resin denture base materials [polycarbonate (Basis PC), ethylene propylene (Duraflex), and polyamide (Valplast)] and one conventional heat-polymerized acrylic resin (PMMA, SR Triplex Hot) denture base, all with a mandibular first molar acrylic resin denture tooth set in were evaluated (n=6). Pressure transmission area and maximum pressure transmission of the specimens under an impact load were observed by using pressure-sensitive sheets. The modulus of elasticity and nanohardness of each denture base (n=10) were measured on 15×15×15×3mm 3 specimen by using an ultramicroindentation system. The pressure transmission area, modulus of elasticity, and nanohardness data were statistically analyzed with 1-way ANOVA, followed by Tamhane or Tukey HSD post hoc test (α=.05). The maximum pressure transmission data were statistically analyzed with Kruskal-Wallis H test, followed by Mann-Whitney U test (α=.05). Polymethyl methacrylate showed significantly larger pressure transmission area and higher maximum pressure transmission than the other groups (Pelasticity and nanohardness among the four types of denture bases (Pelasticity and nanohardness of each type of denture base were demonstrated. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Characterization and bacterial anti-adherent effect on modified PMMA denture acrylic resin containing platinum nanoparticles.

Science.gov (United States)

Nam, Ki-Young

2014-06-01

This study characterized the synthesis of a modified PMMA (Polymethyl methacrylate) denture acrylic loading platinum nanoparticles (PtN) and assessed its bacterial inhibitory efficacy to produce novel antimicrobial denture base material. Polymerized PMMA denture acrylic disc (20 mm × 2 mm) specimens containing 0 (control), 10, 50, 100 and 200 mg/L of PtN were fabricated respectively. The obtained platinum-PMMA nanocomposite (PtNC) was characterized by TEM (transmission electron microscopy), SEM/EDX (scanning electron microscope/energy dispersive X-ray spectroscopy), thermogravimetric and atomic absorption spectrophotometer analysis. In antimicrobial assay, specimens were placed on the cell culture plate, and 100 µL of microbial suspensions of S. mutans (Streptococcus mutans) and S. sobrinus (Streptococcus sobrinus) were inoculated then incubated at 37℃ for 24 hours. The bacterial attachment was tested by FACS (fluorescence-activated cell sorting) analysis after staining with fluorescent probe. PtN were successfully loaded and uniformly immobilized into PMMA denture acrylic with a proper thermal stability and similar surface morphology as compared to control. PtNC expressed significant bacterial anti-adherent effect rather than bactericidal effect above 50 mg/L PtN loaded when compared to pristine PMMA (P=.01) with no or extremely small amounts of Pt ion eluted. This is the first report on the synthesis and its antibacterial activity of Pt-PMMA nanocomposite. PMMA denture acrylic loading PtN could be a possible intrinsic antimicrobial denture material with proper mechanical characteristics, meeting those specified for denture bases. For clinical application, future studies including biocompatibility, color stability and warranting the long-term effect were still required.

Evaluation of the utility of cephalometric parameters in constructing complete denture. Part I: placement of posterior teeth.

Science.gov (United States)

Bassi, F; Deregibus, A; Previgliano, V; Bracco, P; Preti, G

2001-03-01

Various types of parameters, including cephalometric ones, have been used in the construction of complete denture. This study aimed to evaluate the utility of cephalometric parameters for this purpose. The position of the posterior teeth in a group of 42 edentulous patients, successfully rehabilitated with complete denture according to clinical parameters, was evaluated by cephalometrics. The following were determined: vertical dimension of occlusion (VDO); orientation of the occlusal plane; and subdivision of the denture space. The cephalometric parameters do not correspond to the clinical positioning of the posterior teeth in successful rehabilitation with complete denture.

Examination of overlay pipe weldments removed from the Hatch-2 reactor

International Nuclear Information System (INIS)

Park, J.Y.; Kupperman, D.S.; Shack, W.J.

1985-02-01

Laboratory ultrasonic examination (UT), dye penetrant examination (PT), metallography, and sensitization measurements were performed on Type 304 stainless steel overlay pipe weldments from the Hatch-2 BWR to determine the effectiveness of UT through overlays and the effects of the overlays on crack propagation in the weldments. Little correlation was observed between the results of earlier in-service ultrasonic inspection and the results of PT and destructive examination. Considerable difficulty was encountered in correctly detecting the presence of cracks by UT in the laboratory. Blunting of the crack tip by the weld overlay was observed, but there was no evidence of tearing or throughwall extension of the crack beyond the blunted region

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

Science.gov (United States)

Takahashi, Toshihito; Gonda, Tomoya; Tomita, Akiko; Mizuno, Yoko; Maeda, Yoshinobu

2016-01-01

As maxillary implant overdentures are being increasingly used in clinical practice, prosthodontic complications related to these dentures are also reported more often. The purpose of this study was to examine the influence of palatal coverage and implant distribution on the shear strain of maxillary implant overdentures. A maxillary edentulous model with implants inserted in the anterior, premolar, and molar areas was fabricated. Two kinds of experimental overdentures, with and without palatal coverage, were also fabricated, and two strain gauges were attached at the midline of the labial and palatal sides. A vertical occlusal load of 98 N was applied through a mandibular complete denture, and the shear strain in each denture was compared by analysis of variance (P = .05). In all situations, the shear strain in palateless dentures was significantly higher than in dentures with palate on both sides (P overdentures exhibited much higher strain than overdentures with palate regardless of the implant distribution; this may cause more prosthodontic and implant complications. The most favorable configuration to prevent complications in maxillary implant overdentures was palatal coverage that was supported by more than four widely distributed implants.

Tack coat optimization for HMA overlays : accelerated pavement test report.

Science.gov (United States)

2009-02-01

Interface bonding between hot-mix asphalt (HMA) overlays and Portland cement concrete (PCC) pavements is one : of the most significant factors affecting overlay service life. This study was performed to quantify the effects of HMA type, : tack coat t...

Present status of titanium removable dentures--a review of the literature.

Science.gov (United States)

Ohkubo, C; Hanatani, S; Hosoi, T

2008-09-01

Although porcelain and zirconium oxide might be used for fixed partial dental prostheses instead of conventional dental metals in the near future, removable partial denture (RPD) frameworks will probably continue to be cast with biocompatible metals. Commercially pure (CP) titanium has appropriate mechanical properties, it is lightweight (low density) compared with conventional dental alloys, and has outstanding biocompatibility that prevents metal allergic reactions. This literature review describes the laboratory conditions needed for fabricating titanium frameworks and the present status of titanium removable prostheses. The use of titanium for the production of cast RPD frameworks has gradually increased. There are no reports about metallic allergy apparently caused by CP titanium dentures. The laboratory drawbacks still remain, such as the lengthy burn-out, inferior castability and machinability, reaction layer formed on the cast surface, difficulty of polishing, and high initial costs. However, the clinical problems, such as discoloration of the titanium surfaces, unpleasant metal taste, decrease of clasp retention, tendency for plaque to adhere to the surface, detachment of the denture base resin, and severe wear of titanium teeth, have gradually been resolved. Titanium RPD frameworks have never been reported to fail catastrophically. Thus, titanium is recommended as protection against metal allergy, particularly for large-sized prostheses such as RPDs or complete dentures.

Dual Component Removable Partial Denture shows improved ...

African Journals Online (AJOL)

STORAGESEVER

2009-02-18

Feb 18, 2009 ... 2Faculty of Dentistry, the University of Hong Kong, Hong Kong. 3Department of ... an example of poor oral condition caused mainly by periodontitis, and ... working model of the Dual Component Removable Partial Denture.

Modern methods of overlay welding for corrosion protection of power generating equipment

International Nuclear Information System (INIS)

Ershov, A.V.; Shul'man, I.E.; Potapov, N.N.

1989-01-01

Methods for overlay welding of inner surfaces of power equipment for corrosion protection are analysed. Various methods of electroslag overlay welding by a band electrode (overlay welding by two-electrode bands by a wide band with magnetic control, by an electrode band with high melting velocity) are marked to be the most perspective for cladding of NPP vessel equipment

Elastic modulus and flexural strength comparisons of high-impact and traditional denture base acrylic resins

Directory of Open Access Journals (Sweden)

Nour M. Ajaj-ALKordy

2014-01-01

Conclusion: Within the limitations of this study, it can be concluded that the high-impact acrylic resin is a suitable denture base material for patients with clinical fracture of the acrylic denture.

VT Data - Overlay District 20170419, Colchester

Data.gov (United States)

Vermont Center for Geographic Information — The following Overlay Districts are included in the data:General Development Four Commercial DistrictGeneral Development Four Openspace DistrictShoreland...

The importance of a two-step impression procedure for complete denture fabrication: a systematic review of the literature.

Science.gov (United States)

Regis, R R; Alves, C C S; Rocha, S S M; Negreiros, W A; Freitas-Pontes, K M

2016-10-01

The literature has questioned the real need for some clinical and laboratory procedures considered essential for achieving better results for complete denture fabrication. The aim of this study was to review the current literature concerning the relevance of a two-step impression procedure to achieve better clinical results in fabricating conventional complete dentures. Through an electronic search strategy of the PubMed/MEDLINE database, randomised controlled clinical trials which compared complete denture fabrication in adults in which one or two steps of impressions occurred were identified. The selections were made by three independent reviewers. Among the 540 titles initially identified, four studies (seven published papers) reporting on 257 patients evaluating aspects such as oral health-related quality of life, patient satisfaction with dentures in use, masticatory performance and chewing ability, denture quality, direct and indirect costs were considered eligible. The quality of included studies was assessed according to the Cochrane guidelines. The clinical studies considered for this review suggest that a two-step impression procedure may not be mandatory for the success of conventional complete denture fabrication regarding a variety of clinical aspects of denture quality and patients' perceptions of the treatment. © 2016 John Wiley & Sons Ltd.

Method of Retention Control for Compromised Periodontal Bone Support Abutment of Conical Crown Retained Denture

Directory of Open Access Journals (Sweden)

Chau-Hsiang Wang

2010-08-01

Full Text Available Conical crown-retained dentures (CCRD show a higher survival rate and greater patient satisfaction than transitional removable partial dentures during long-term follow-up. However, unsustainable denture retention force on supporting abutments after initial delivery and loss retention are frequently seen in long-term follow-up of clinical cases. The main causes are insufficient information concerning denture retention designs and the retention-tolerance of the supporting abutments. Monitoring by dental technicians of the quality of dental prostheses is critical. This case report describes an optimal method for CCRD construction that determines and distributes an optimal denture retention force on the supporting abutments to allow the patient to easily remove the denture while ensuring that the CCRD remains in place during physiologic activities. Oral rehabilitation with CCRD should consider the condition of the abutment periodontal support, the interarch occlusal relationship, supplemental fatigue of the terminal abutment, and patient's estimated bite force. The effects of friction on the abutment's inner crown were based on an optimal a angle. The dental laboratory used these measurements to fabricate a CCRD using a Koni-Meter to adjust the retention of the inner crown. This method protects the abutments and reduces the wear between the inner and outer crowns. The CCRD achieved good esthetic results and physiologic functions. Periodic long-term follow-up of the patient and CCRD after initial placement is recommended.

Overlay Spectrum Sharing using Improper Gaussian Signaling

KAUST Repository

Amin, Osama

2016-11-30

Improper Gaussian signaling (IGS) scheme has been recently shown to provide performance improvements in interference limited networks as opposed to the conventional proper Gaussian signaling (PGS) scheme. In this paper, we implement the IGS scheme in overlay cognitive radio system, where the secondary transmitter broadcasts a mixture of two different signals. The first signal is selected from the PGS scheme to match the primary message transmission. On the other hand, the second signal is chosen to be from the IGS scheme in order to reduce the interference effect on the primary receiver. We then optimally design the overlay cognitive radio to maximize the secondary link achievable rate while satisfying the primary network quality of service requirements. In particular, we consider full and partial channel knowledge scenarios and derive the feasibility conditions of operating the overlay cognitive radio systems. Moreover, we derive the superiority conditions of the IGS schemes over the PGS schemes supported with closed form expressions for the corresponding power distribution and the circularity coefficient and parameters. Simulation results are provided to support our theoretical derivations.

Comparison Predominant Oral micro-flora in Subjects with and without Complete Denture Referred to Yazd Dentistry Department

Directory of Open Access Journals (Sweden)

Abbas Ali Jafari

2014-11-01

Results: The non-aureus staphylococcus and alpha-hemolytic streptococci showed the highest positive culture among the isolated microorganisms in both groups, whereas beta hemolytic streptococci showed the least percent of isolated microorganism in both groups. The higher density of non-aureus Staphylococci, α-hemolitic Streptococci, Gram negative cocobasillus, non-pathogenic Neisseria, Candida and Corynebacterium were recovered from oral samples of denture users in compare with dentate subjects (P= 0.0001. There was also seen a statistical significant correlation between the number of isolated microorganisms and the duration of denture utilization in denture users (P=0.013. Conclusion: Results of the present study showed that complete denture can be act as a predisposal factor in overgrowing of several oral micro-flora particularly Candida, non-aureus Staphylococci, α-hemolytic streptococci, gram negative cocobacillus, non-pathogenic Neisseria, and Corynebacterium, which emphasized the users denture hygine.

Application of advanced diffraction based optical metrology overlay capabilities for high-volume manufacturing

Science.gov (United States)

Chen, Kai-Hsiung; Huang, Guo-Tsai; Hsieh, Hung-Chih; Ni, Wei-Feng; Chuang, S. M.; Chuang, T. K.; Ke, Chih-Ming; Huang, Jacky; Rao, Shiuan-An; Cumurcu Gysen, Aysegul; d'Alfonso, Maxime; Yueh, Jenny; Izikson, Pavel; Soco, Aileen; Wu, Jon; Nooitgedagt, Tjitte; Ottens, Jeroen; Kim, Yong Ho; Ebert, Martin

2017-03-01

On-product overlay requirements are becoming more challenging with every next technology node due to the continued decrease of the device dimensions and process tolerances. Therefore, current and future technology nodes require demanding metrology capabilities such as target designs that are robust towards process variations and high overlay measurement density (e.g. for higher order process corrections) to enable advanced process control solutions. The impact of advanced control solutions based on YieldStar overlay data is being presented in this paper. Multi patterning techniques are applied for critical layers and leading to additional overlay measurement demands. The use of 1D process steps results in the need of overlay measurements relative to more than one layer. Dealing with the increased number of overlay measurements while keeping the high measurement density and metrology accuracy at the same time presents a challenge for high volume manufacturing (HVM). These challenges are addressed by the capability to measure multi-layer targets with the recently introduced YieldStar metrology tool, YS350. On-product overlay results of such multi-layers and standard targets are presented including measurement stability performance.

VT Data - Overlay District 20070306, Marlboro

Data.gov (United States)

Vermont Center for Geographic Information — Cartographic version of overlay district (surface water buffer), Marlboro, Vermont. Base zoning districts are in a separate shapefile. Data were originally created...

Fabrication of titanium alloy frameworks for complete dentures by selective laser melting.

Science.gov (United States)

Kanazawa, Manabu; Iwaki, Maiko; Minakuchi, Shunsuke; Nomura, Naoyuki

2014-12-01

Casting difficulties have led to the limited use of titanium in dental prostheses. The selective laser melting system was recently developed to fabricate biomedical components from titanium alloys. However, the fabrication of a titanium alloy framework for a maxillary complete denture by selective laser melting has not yet been investigated. The purpose of the study was to fabricate thin titanium alloy frameworks for a maxillary complete denture with a selective laser melting system and to evaluate their hardness and microstructure. A cast of an edentulous maxilla was scanned with a dental 3-dimensional cone-beam computed tomography system, and standard triangulation language data were produced with the DICOM Viewer (Digital Imaging and Communications in Medicine). Two types of metal frameworks for complete dentures were designed with 3-dimensional computer-aided design software. Two titanium alloy frameworks, SLM-1 and SLM-2, were fabricated from these designs with the selective laser melting system. Plate-shaped specimens were cut from the central flat region of SLM-1, SLM-2, and as-cast Ti-6Al-4V (As-cast). Vickers hardness testing, optical microscopy, and x-ray diffraction measurements were performed. Thin titanium alloy frameworks for maxillary complete dentures could be fabricated by selective laser melting. The hardness values for SLM-1 and SLM-2 were higher than that for the as-cast specimen. Optical microscopy images of the SLM-1 and SLM-2 microstructure showed that the specimens did not exhibit pores, indicating that dense frameworks were successfully obtained with the selective laser melting process. In the x-ray diffraction patterns, only peaks associated with the α phase were observed for SLM-1 and SLM-2. In addition, the lattice parameters for SLM-1 and SLM-2 were slightly larger than those for the as-cast specimen. The mechanical properties and microstructure of the denture frameworks prepared by selective laser melting indicate that these dentures

Visualization of Disciplinary Profiles: Enhanced Science Overlay Maps

Directory of Open Access Journals (Sweden)

Stephen Carley

2017-08-01

Full Text Available Purpose: The purpose of this study is to modernize previous work on science overlay maps by updating the underlying citation matrix, generating new clusters of scientific disciplines, enhancing visualizations, and providing more accessible means for analysts to generate their own maps. Design/methodology/approach: We use the combined set of 2015 Journal Citation Reports for the Science Citation Index (n of journals = 8,778 and the Social Sciences Citation Index (n = 3,212 for a total of 11,365 journals. The set of Web of Science Categories in the Science Citation Index and the Social Sciences Citation Index increased from 224 in 2010 to 227 in 2015. Using dedicated software, a matrix of 227 × 227 cells is generated on the basis of whole-number citation counting. We normalize this matrix using the cosine function. We first develop the citing-side, cosine-normalized map using 2015 data and VOSviewer visualization with default parameter values. A routine for making overlays on the basis of the map (“wc15.exe” is available at http://www.leydesdorff.net/wc15/index.htm. Findings: Findings appear in the form of visuals throughout the manuscript. In Figures 1–9 we provide basemaps of science and science overlay maps for a number of companies, universities, and technologies. Research limitations: As Web of Science Categories change and/or are updated so is the need to update the routine we provide. Also, to apply the routine we provide users need access to the Web of Science. Practical implications: Visualization of science overlay maps is now more accurate and true to the 2015 Journal Citation Reports than was the case with the previous version of the routine advanced in our paper. Originality/value: The routine we advance allows users to visualize science overlay maps in VOSviewer using data from more recent Journal Citation Reports.

Analysis of the effects of removable dentures on the psychological status, quality of life, and masticatory function of the elderly

Science.gov (United States)

Dyas, R.; Nathanael, M.; Indrasari, M.; Masulili, C.; Rahardjo, T. B.; Agustin, D.; Hogervorst, E.; Kusdhany, L.

2017-08-01

Older age is a major risk factor for diseases of the teeth and mouth and dementia. Diseases of the teeth and mouth can lead to tooth loss. The use of removable dentures can help the elderly to replace lost teeth; therefore, dentures are expected to improve the masticatory function, quality of life, and psychological status of the elderly. The aim of this study was to analyze the effects of removable denture usage on the improvement of the psychological status, quality of life, and masticatory function of elderly people. The data was obtained from 30 respondents. The patients answered questionnaires before they used the dentures, 2 weeks after they began using dentures, and 2 months after they started wearing dentures. Four different questionnaires were used: EuroQol Five Dimensions questionnaire (EQ-5D) and Geriatric Depression Scale (GDS), to measure psychological status; a mastication questionnaire to measure masticatory function; and a validated quality of life questionnaire. Based on the results of this study, it is clear that after 2 months of denture usage, removable dentures in the elderly can significantly improve their quality of life, masticatory function, and psychological status(p<0.05).

The effectiveness of adhesives on the retention of mandibular free end saddle partial dentures: An in vitro study.

Science.gov (United States)

Quiney, Daniel; Nishio Ayre, Wayne; Milward, Paul

2017-07-01

Existing in vitro methods for testing denture adhesives do not fully replicate the complex oral geometries and environment; and in vivo methods are qualitative, prone to bias and not easily reproducible. The purpose of this study was to develop a novel, quantitative and more accurate model to test the effect of adhesives on the retentive force of mandibular free end saddle partial dentures. An in vitro model was developed based on an anatomically accurate cast of a clinical case. Experimentally, the amount of adhesive was varied (0.2g-1g) and the tensile force required for displacement was measured. Different commercially available adhesives were then tested at the optimum volume using the in vitro model. A 3D finite element model of the denture was used to assess how the forces to induce denture displacement varied according to the position of the force along the saddle length. The mass of adhesive was found to significantly alter retention forces, with 0.4-0.7g being the optimum range for this particular scenario. Use of adhesives significantly improved mandibular free end saddle partial denture retention with the worst performing adhesive increasing retention nine-fold whilst the best performing adhesive increased retention twenty three-fold. The finite element model revealed that 77% more force was required to displace the denture by positioning forces towards the mesial end of the saddle compared to the distal end. An in vitro denture adhesive model was developed, which demonstrated that mass of adhesive plays a significant role in enhancing denture retention and supported the design principle of placing as few teeth as clinically necessary on the distal end of the free end saddles. Limiting the position of teeth on free end saddles to the mesial and mid portion of the saddle will reduce displacements caused by mastication. The movement of mandibular free end saddle partial dentures can be restricted with the use of denture adhesives. Altering the mass of

Rresence of different Candida species at denture wearers with type 2 diabetes and clinically healthy oral mucosa: Pilot study

OpenAIRE

Matić-Petrović, Sanja; Barać, Milena; Kuzmanović-Pfićer, Jovana; Radunović, Milena; Jotić, Aleksandra; Pucar, Ana

2018-01-01

Background/Aim: The aim of this study was to examine prevalence of different Candida spp. at diabetics and nondiabetics wearing dentures without clinical signs of Denture Stomatitis (DS) and to study if some local and systematic factors are confounders for harboring Candida at these subjects. Material and Methods: Total of 60 subjects wearing partial or complete upper acrylic denture having at least half of palatal mucosa covered by denture were selected and stratified into three experimental...

Effect of long-term water immersion or thermal shock on mechanical properties of high-impact acrylic denture base resins.

Science.gov (United States)

Sasaki, Hirono; Hamanaka, Ippei; Takahashi, Yutaka; Kawaguchi, Tomohiro

2016-01-01

The purpose of this study was to investigate the effect of long-term water immersion or thermal shock on the mechanical properties of high-impact acrylic denture base resins. Two high-impact acrylic denture base resins were selected for the study. Specimens of each denture base material tested were fabricated according to the manufacturers' instructions (n=10). The flexural strength at the proportional limit, the elastic modulus and the impact strength of the specimens were evaluated. The flexural strength at the proportional limit of the high-impact acrylic denture base resins did not change after six months' water immersion or thermocycling 50,000 times. The elastic moduli of the high-impact acrylic denture base resins significantly increased after six months' water immersion or thermocycling 50,000 times. The impact strengths of the high-impact acrylic denture base resins significantly decreased after water immersion or thermocycling as described above.

Effects of Reinforcement on Denture Strain in Maxillary Implant Overdentures: An In Vitro Study Under Various Implant Configurations.

Science.gov (United States)

Takahashi, Toshihito; Gonda, Tomoya; Maeda, Yoshinobu

Maxillary implant overdentures are often designed without palatal coverage to maximize wearer comfort. Although palateless dentures have been reported to be less rigid than conventional dentures, and require reinforcement to prevent complications, there is little documentation about the effects of such reinforcement. The purpose of this study was to examine the effects of reinforcement on the strain on maxillary implant overdentures supported by implants in a variety of configurations. A maxillary edentulous model with implants inserted in the anterior, premolar, and molar area was fabricated. Five types of experimental overdentures, with and without reinforcement, were fabricated, and two strain gauges were attached at the anterior midline of the labial and palatal sides. A vertical occlusal load of 98 N was applied through a mandibular complete denture, and the shear strain on the denture was measured. The measurements were compared using the Kruskal-Wallis test (P = .05). On both the labial and palatal sides, the strain on the palateless dentures with reinforcement was significantly lower than the strain on palateless dentures without reinforcement in all implant configurations (P overdenture with residual ridge reinforcement and a palatal bar could reduce the strain in the anterior midline to almost the same level as a denture with palatal coverage. This type of reinforcement may prevent prosthetic and implant complications.

Influence of the mechanical properties of resilient denture liners on the retention of overdenture attachments.

Science.gov (United States)

Kubo, Keitaro; Koike, Takashi; Ueda, Takayuki; Sakurai, Kaoru

2018-03-15

Information is lacking about the selection criteria for silicone resilient denture liners applied as a matrix material for attachments on overdentures. The purpose of this in vitro study was to investigate the mechanical properties of silicone resilient denture liners and their influence on the initial retention force of overdenture attachments and the reduction in retention force over time. Nine types of silicone resilient denture liner were injected and fixed to the matrix section of an experimental denture base. They were then fitted to an epoxy resin model that simulated the residual ridge with a patrix ball attachment (n=10). The retention force of the denture was measured with a digital force gauge, and the maximum force of traction (N) was regarded as the initial retention force. The retention force reduction (N) after repeated insertion and removal (n=5) was calculated by subtracting the retention force after 3348 cycles (3-year simulated insertion and removal) from the initial retention force. The intaglio of the matrix was observed with a scanning electron microscope (SEM) before and after the 3348 cycles. Four mechanical properties (hardness, strain-in-compression, tensile strength, and arithmetic mean roughness) of the resilient denture liners were measured. One-way ANOVA of the initial retention force of each lining material was performed, followed by the Scheffe test (α=.05). Pearson correlation analysis was used (α=.05) to analyze correlations of the initial retention force with the retention force reduction after insertion and removal and the mechanical properties of each material. Multiple regression analysis with the stepwise method extracted the initial retention force and the retention force reduction as dependent variables, and the resilient denture liner mechanical properties as explanatory variables (α=.05). The initial retention force of the resilient denture liners was 1.3 to 5.4 N. Multiple comparisons showed significant differences in

Thoracoscopic retrieval of a "smiling" foreign body from the proximal esophagus: an impacted denture.

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Palanivelu, Chinnusamy; Rangarajan, Muthukumaran; Parthasarathi, Ramakrishnan; Senthilnathan, Palaniswamy

2008-06-01

The esophagus is a common site for foreign bodies (FBs) because of areas of physiologic narrowing. Dentures pose special problems, especially if they are impacted. We present a case of a "smiling" foreign body in the proximal esophagus. The patient was an 80-year-old man with a history of dysphagia and swallowed dentures. Thoracoscopic removal was performed successfully as an endoscopic removal had failed and the patient had an uneventful postoperative recovery. He was discharged on the seventh postoperative day. Coins are the most commonly ingested FBs. Swallowing of dentures is found mostly in elderly patients. If endoscopic removal is not possible, then a minimally invasive surgery is an alternative. Swallowing of dentures is rare, and its thoracoscopic removal has not been reported so far. Using thoracoscopy, all the benefits of a minimally invasive surgery can be used. Minimally invasive techniques have been found to be very useful in the removal of intraluminal FBs, especially when conservative measures fail. Prevention of such incidents should be emphasized.

Comparison of recognition about denture adhesive between Japanese and Indonesian dentists: A pilot study

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Shinsuke Sadamori

2005-12-01

Full Text Available The purpose of this study was to compare cross-national differences of the recognition of denture adhesive among dentists. The design of the research was cross-cultural differences. The research was done in Japan and Indonesia. One hundred and ten dentists from Japan and Indonesia were surveyed using a questionnaire regarding knowledge/comprehension of denture adhesive (in Japanese and Indonesian versions respectively. Logistic regression model (forward stepwise method showed that it was possible to distinguish Japanese dentists from Indonesian peers with a probability of 96.0 per cent by using 4 items out of 16. For the question of "How many domestic products of denture adhesive (DA do you know?" approximately a half of the Japanese dentists answered "less than 3", whereas 93 per cent of Indonesian subjects answered "nothing". It was concluded that there were much differences in dentists' understanding and experience of denture adhesive in the clinic, between Japan and Indonesia.

Evaluation of gloss changes of two denture acrylic resin materials in four different beverages.

Science.gov (United States)

Keyf, Filiz; Etikan, Ilker

2004-03-01

The primary disadvantages of the materials which are used in construction of complete and removable partial dentures is that their esthetic, physical and mechanical properties change rapidly with time in the oral environment. For esthetics, color stability is one of the criteria that needs careful attention. Color may provide important information on the serviceability of these materials. Color change affects the gloss of these materials. The objective of the present study was to determine the gloss changes resulting from the testing process in four different beverages in one heat-polymerized denture base resin and one cold-polymerized denture base repair resin. Thirty-six samples were fabricated for each material. Each sample had a smooth polished and a rough unpolished surface. The gloss measurements were made with a glossmeter before testing. Four different beverages (tea, coffee, cola and cherry juice) were used for testing. Two angles of illumination (20 and 60 degrees) were used for the gloss measurements. The samples were immersed in water, tea, coffee, cola and cherry juice solutions. The gloss of the samples was measured again with the glossmeter at the end of the 45th day and 135th day of testing. The arithmetic mean and standard deviation of each of the samples were calculated and compared with each other statistically by using the Wilcoxon test (within times) (p gloss changes occurred after testing in heat-polymerized denture base resin and cold-polymerized denture base repair resin. The significance of the gloss changes exhibited by each sample, kept for different lengths of time in the same solution, were compared using the Wilcoxon test. The results were statistically significant (p 0.05), but the difference between smooth polished and rough unpolished surfaces was statistically significant (p gloss of heat-polymerized denture base resin or the gloss of cold-polymerized denture base repair resin was affected by tested agents, and the four beverages

Daya Hambat Infusum Daun Sirih Terhadap Pertumbuhan Staphylococcus aureus Yang Diisolasi Dari Denture Stomatitis ; Penelitian In Vitro.

OpenAIRE

bin Abdullah, Muhammad Naim

2011-01-01

Denture Stomatitis merupakan lesi mukosa oral berwarna merah, sakit, dan bengkak, kondisi ini karena kebiasaan jelek pada pemakai gigitiruan yang tidak mumbuka protesa pada malam hari dan jarang dibersihkan. Faktor sistemik yang mendukung terjadinya Denture Stomatitis dapat disebabkan oleh beberapa bakteri, salah satunya Staphylococcus aureus. Pencegahan Denture Stomatitis dapat dilakukan dengan sering membersihkan gigitiruan dan pemakaian obat kumur. Tujuan penelitian ini adalah untuk menguj...

Axial compression behavior of concrete masonry wallettes strengthened with cement mortar overlays

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F. L. De Oliveira

Full Text Available This paper presents the results of a series of axial compression tests on concrete block wallettes coated with cement mortar overlays. Different types of mortars and combinations with steel welded meshes and fibers were tested. The experimental results were discussed based on different theoretical approaches: analytical and Finite Element Method models. The main conclusions are: a the application of mortar overlays increases the wall strength, but not in a uniform manner; b the strengthening efficiency of wallettes loaded in axial compression is not proportional to the overlay mortar strength because it can be affected by the failure mechanisms of the wall; c steel mesh reinforced overlays in combination with high strength mortar show better efficiency, because the steel mesh mitigates the damage effects in the block wall and in the overlays themselves; d simplified theoretical methods of analysis as described in this paper can give satisfactory predictions of masonry wall behavior up to a certain level.

A review of computer-aided design/computer-aided manufacture techniques for removable denture fabrication

Science.gov (United States)

Bilgin, Mehmet Selim; Baytaroğlu, Ebru Nur; Erdem, Ali; Dilber, Erhan

2016-01-01

The aim of this review was to investigate usage of computer-aided design/computer-aided manufacture (CAD/CAM) such as milling and rapid prototyping (RP) technologies for removable denture fabrication. An electronic search was conducted in the PubMed/MEDLINE, ScienceDirect, Google Scholar, and Web of Science databases. Databases were searched from 1987 to 2014. The search was performed using a variety of keywords including CAD/CAM, complete/partial dentures, RP, rapid manufacturing, digitally designed, milled, computerized, and machined. The identified developments (in chronological order), techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication are summarized. Using a variety of keywords and aiming to find the topic, 78 publications were initially searched. For the main topic, the abstract of these 78 articles were scanned, and 52 publications were selected for reading in detail. Full-text of these articles was gained and searched in detail. Totally, 40 articles that discussed the techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication and the articles were incorporated in this review. Totally, 16 of the papers summarized in the table. Following review of all relevant publications, it can be concluded that current innovations and technological developments of CAD/CAM and RP allow the digitally planning and manufacturing of removable dentures from start to finish. As a result according to the literature review CAD/CAM techniques and supportive maxillomandibular relationship transfer devices are growing fast. In the close future, fabricating removable dentures will become medical informatics instead of needing a technical staff and procedures. However the methods have several limitations for now. PMID:27095912

Latex-modified fiber-reinforced concrete bridge deck overlay : construction/interim report.

Science.gov (United States)

1993-06-01

Latex-modified concrete (LMC) is Portland cement concrete (PCC) with an admixture of latex. LMC is considered to be nearly impermeable to chlorides and is extensively used to construct bridge deck overlays. Unfortunately, some of these overlays have ...

A Persistent Structured Hierarchical Overlay Network to Counter Intentional Churn Attack

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Ramanpreet Kaur

2016-01-01

Full Text Available The increased use of structured overlay network for a variety of applications has attracted a lot of attention from both research community and attackers. However, the structural constraints, open nature (anybody can join and anybody may leave, and unreliability of its participant nodes significantly affect the performance of these applications and make it vulnerable to a variety of attacks such as eclipse, Sybil, and churn. One attack to compromise the service availability in overlay network is intentional churn (join/leave attack, where a large number of malicious users will join and leave the overlay network so frequently that the entire structure collapses and becomes unavailable. The focus of this paper is to provide a new robust, efficient, and scalable hierarchical overlay architecture that will counter these attacks by providing a structure that can accommodate the fleeting behaviour of nodes without causing much structural inconsistencies. The performance evaluation showed that the proposed architecture has more failure resilience and self-organization as compared to chord based architecture. Experimental results have demonstrated that the effect of failures on an overlay is proportional to the size of failure.

Characterisation of hydrocarbonaceous overlayers important in metal-catalysed selective hydrogenation reactions

Energy Technology Data Exchange (ETDEWEB)

Lennon, David; Warringham, Robbie [School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Guidi, Tatiana [ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Parker, Stewart F., E-mail: stewart.parker@stfc.ac.uk [ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom)

2013-12-12

Highlights: • Inelastic neutron scattering spectroscopy of a commercial dehydrogenation catalyst. • The overlayer present on the catalyst is predominantly aliphatic. • A population of strongly hydrogen bonded hydroxyls is also present. - Abstract: The hydrogenation of alkynes to alkenes over supported metal catalysts is an important industrial process and it has been shown that hydrocarbonaceous overlayers are important in controlling selectivity profiles of metal-catalysed hydrogenation reactions. As a model system, we have selected propyne hydrogenation over a commercial Pd(5%)/Al{sub 2}O{sub 3} catalyst. Inelastic neutron scattering studies show that the C–H stretching mode ranges from 2850 to 3063 cm{sup −1}, indicating the mostly aliphatic nature of the overlayer and this is supported by the quantification of the carbon and hydrogen on the surface. There is also a population of strongly hydrogen-bonded hydroxyls, their presence would indicate that the overlayer probably contains some oxygen functionality. There is little evidence for any olefinic or aromatic species. This is distinctly different from the hydrogen-poor overlayers that are deposited on Ni/Al{sub 2}O{sub 3} catalysts during methane reforming.

Influence of the fast-processing technique on the number of the occlusal contacts and occlusal vertical dimension of complete dentures.

Science.gov (United States)

Atashrazm, Parsa; Alavijeh, Leila Zamani; Afshar, Maryam Sadat Sadrzadeh

2011-03-01

Occlusal errors during acryl processing affect the retention and stability of complete dentures. The aim of the present study was to assess the influence of a short curing technique on the number of occlusal contacts and the occlusal vertical dimension (OVD) of complete dentures. Complete dentures were prepared. The number of occlusal contacts was recorded in centric relation (CR) using 60 µ articulation paper. The OVD was recorded with the waxed trial denture in place. Dentures were then invested and processed with compression molding and short cure water bath technique. The number of occlusal contacts was recorded again. The amount of pin opening was measured for all of the complete dentures on the articulator. Data were analyzed with paired t-test to determine the alterations. The mean number of occlusal contacts before and after processing was 10.9 ± 2.4 and 6.3 ± 3.1 respectively (4.7 ± 1.9 decrease; p negative effect on the morphologic pattern of artificial teeth of complete dentures and thus should be used carefully.

Evaluation of the Periodontal Status of Abutment Teeth in Removable Partial Dentures.

Science.gov (United States)

Correia, André Ricardo Maia; da Silva Lobo, Fábio Daniel; Miranda, Mónica Célia Pereira; Framegas de Araújo, Filipe Miguel Soares; Santos Marques, Tiago Miguel

2017-12-15

The purpose of this study was to evaluate whether the use of removable partial dentures affects the periodontal status of abutment teeth. An observational cross-sectional study was done on a sample of patients rehabilitated with removable partial dentures (2010 to 2013). At a recall appointment, a clinical examination was done to collect data related to the rehabilitation and periodontal status of the abutment teeth. Of 145 invited patients, 54 attended the requested follow-up appointment (37.2%). Mean patient age was 59.1 years, and the study population was 42.6% male and 57.4% female. The mean follow-up time for the prosthesis was 26 months. Abutment teeth had higher values in all periodontal variables (P removable partial dentures is affected by these rehabilitations. A recall program for these patients involving removable prosthodontics and periodontology appointments is mandatory.

Overdenture retained by teeth using a definitive denture base technique: a case report.

Science.gov (United States)

Nascimento, D F F; dos Santos, J F F; Marchini, L

2010-09-01

This paper presents a technique involving the use of a definitive denture base to make overdentures. Cores with ball attachments were cemented over remaining lower teeth. Impressions of the edentulous maxilla and mandible were taken to obtain a definitive acrylic resin base. The definitive base of the mandible was perforated at the location of ball attachments and its female components were fixed to the base using acrylic resin directly in the patient's mouth. Wax rims were then made, jaw relationships recorded, teeth mounted and tried in, and the dentures were cured. This technique allowed for easy fixing of female components and better retention during the recording of jaw relationships, and can also be used in the construction of implant retained dentures.

Prevalence of signs and symptoms of temporomandibular disorders (TMD) in patients wearing bimaxillary complete dentures, removable partial dentures and in students with natural dentition.

Science.gov (United States)

Bordin, Thaisa B; Conci, Ricardo A; Pezzini, Maristela M G; Pezzini, Rolando P; Mendonça, Márcio J

2013-01-01

Temporomandibular Disorder (TMD) has attained a prominent role within the context of dental care due to its high prevalence. The aim of this study was to evaluate the prevalence of signs and symptoms of TMD in students at the State University of West of Paraná (UNIOESTE) with natural dentition, and in patients with removable partial dentures and double complete dentures. A total of 210 randomly selected individuals of both genders were evaluated, being divided into three groups: seventy students at the UNIOESTE with natural dentition (Group 1), seventy patients with removable partial dentures (Group 2) and seventy patients with bimaxillary complete dentures (Group 3). The data were collected by a single examiner using the American Academy of Orofacial Pain questionnaire for triage, where a single affirmative response to any of the situations mentioned was enough to carry out clinical evaluation. Kolmogorov Smirnov, Mann Whitney, Chi-Square, ANOVA and Tukey's statistical tests were performed. The most prevalent signs and symptoms of TMD in Group 1 were pain or difficulty in chewing or talking, perception of recent change in bite and deviations during the course of mandibular movements. In Group 2 they were perceptions of recent changes in the bite, deflections in the mandibular movements, presence of joint sounds, pain during excursive movements and muscle tenderness. The most prevalent signs and symptoms in Group 3 were limited to mouth opening and poor stability and retention of at least one of the prostheses. Group 3 also reported having received treatment for headaches or facial pain with a high prevalence. Group 2 had the highest prevalence of signs and symptoms. Prevalence was similar in Groups 1 and 3.

Presence of Different Candida Species at Denture Wearers With Type 2 Diabetes and Clinically Healthy Oral Mucosa-Pilot Study

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Petrović Sanja Matić

2018-03-01

Full Text Available Background/Aim: The aim of this study was to examine prevalence of different Candida spp. at diabetics and nondiabetics wearing dentures without clinical signs of Denture Stomatitis (DS and to study if some local and systematic factors are confounders for harboring Candida at these subjects. Material and Methods: Total of 60 subjects wearing partial or complete upper acrylic denture having at least half of palatal mucosa covered by denture were selected and stratified into three experimental groups: systematically health subjects; patients with diagnosed Type 2 Diabetes (T2D and good glycoregulation; and T2D subjects with poorly regulated blood sugar level. Cotton swab samples were obtained from each patient from hard palate mucosa and denture surface. Swab cultures were made on Sabouraud dextrose agar and ChromAgar Media for distinciton of various Candida spp. Density growth was also measured. Results: Frequency of Candida spp. findings were similar between groups. At healthy subjects, only C.albicans was detected. At diabetics, C.albicans was the most common isolated species, followed by C.glabrata and C.tropicalis. Negative finding of yeasts on palatal mucosa, but positive on denture surface were detected at all groups, with the highest frequency (33.4% at diabetics with poor glycoregulation. Denture surface was heavier colonized than hard palate mucosa. Duration of diabetes in years were only independent predictors for harboring Candida spp. at denture surface (Exp B=1.186, CI=1.047-1.344, p=0.007. Conclusions: Prosthesis of denture wearers without DS may serve as reservoir of Candida spp. Presence of more pathogenic and resistant non-albicans species are related to diabetics, even without clinical signs of DS.

Speech intelligibility enhancement after maxillary denture treatment and its impact on quality of life.

Science.gov (United States)

Knipfer, Christian; Riemann, Max; Bocklet, Tobias; Noeth, Elmar; Schuster, Maria; Sokol, Biljana; Eitner, Stephan; Nkenke, Emeka; Stelzle, Florian

2014-01-01

Tooth loss and its prosthetic rehabilitation significantly affect speech intelligibility. However, little is known about the influence of speech deficiencies on oral health-related quality of life (OHRQoL). The aim of this study was to investigate whether speech intelligibility enhancement through prosthetic rehabilitation significantly influences OHRQoL in patients wearing complete maxillary dentures. Speech intelligibility by means of an automatic speech recognition system (ASR) was prospectively evaluated and compared with subjectively assessed Oral Health Impact Profile (OHIP) scores. Speech was recorded in 28 edentulous patients 1 week prior to the fabrication of new complete maxillary dentures and 6 months thereafter. Speech intelligibility was computed based on the word accuracy (WA) by means of an ASR and compared with a matched control group. One week before and 6 months after rehabilitation, patients assessed themselves for OHRQoL. Speech intelligibility improved significantly after 6 months. Subjects reported a significantly higher OHRQoL after maxillary rehabilitation with complete dentures. No significant correlation was found between the OHIP sum score or its subscales to the WA. Speech intelligibility enhancement achieved through the fabrication of new complete maxillary dentures might not be in the forefront of the patients' perception of their quality of life. For the improvement of OHRQoL in patients wearing complete maxillary dentures, food intake and mastication as well as freedom from pain play a more prominent role.

Stereotactic radiosurgery with an upper partial denture

International Nuclear Information System (INIS)

Tayama, Shusaku; Kunieda, Etsuo; Takeda, Atsushi; Takeda, Toshiaki; Oku, Yohei

2009-01-01

A 54-year-old male with partial denture underwent stereotactic radiosurgery with an infrared camera-guided system for a metastatic brain tumor arising from lung cancer. Although this method utilizes a biteplate mounted on the upper jaw to detect head movement, the patient only had four teeth in his upper jaw. In order to stabilize the biteplate, the maxillary denture was fixed to the biteplate with an autopolymerizing resin. In addition, the rest-occlusal position of the lower jaw was impressed on the inferior surface of the biteplate with an autopolymerizing resin. To assess reproducibility and stability, the distance between the left and right incus and left and right markers was measured during pre-planning, as well as before and after stereotactic irradiation. Wearing the biteplate ensures the accuracy of radiotherapy planning for the implementation of radiosurgery in patients who have many maxillary teeth missing. However, a large degree of error was observed when the biteplate was removed. (author)

[Anterior guidance in complete dentures].

Science.gov (United States)

Dubreuil, J; Trevelo, A

1990-01-01

Although the anterior guidance in complete dentures is not really a guide, the arrangement of the anterior maxillary and mandibular prosthetic teeth, defines a propulsive line called the virtual anterior guidance, a part from the cinematic criterias. The influence of this guide on cuspal movement is superior, in all mandibular points, to the influence of the condylar pathway. If this line is not respected, the practitioner may have to do excessive grindings during occlusal adjustments.

Relevance of variations in the opposing dentition for the functionality of fixed and removable partial dentures: a systematic review.

Science.gov (United States)

Pommer, Bernhard; Krainhöfner, Martin; Watzek, Georg; Tepper, Gabor; Dintsios, Charalabos-Markos

2012-01-01

The aim of this systematic review was to evaluate the functionality of fixed and removable partial dentures as test interventions in relation to variations in the opposing dentition and their prosthetic restoration. The abstracts identified in the respective databases were screened independently by two investigators. RCTs and uncontrolled studies were considered, provided the patients were included consecutively and the confounding variables were adequately monitored. Seventeen papers were included. The study and publication quality was assessed using a "biometric quality" tool showing an overall poor quality. The reported outcomes, such as survival rates, were in each case obtained from a single study. Two possible trends could be deduced for the endpoint longevity: (a) the first trend in favor of removable partial dentures, compared to fixed partial dentures, with a fully edentulous opposing arch fitted with a removable prosthesis; (b) the second trend in favor of implant-supported partial dentures, compared to conventionally fixed partial dentures, with natural opposing dentition or with a removable partial denture in the opposing arch. No evidence could be generated as to whether, and if so how, variations in the opposing dentition have a bearing on the decision to fit a partially edentulous arch with a fixed or removable partial denture.

Relevance of Variations in the Opposing Dentition for the Functionality of Fixed and Removable Partial Dentures: A Systematic Review

Directory of Open Access Journals (Sweden)

Bernhard Pommer

2012-01-01

Full Text Available The aim of this systematic review was to evaluate the functionality of fixed and removable partial dentures as test interventions in relation to variations in the opposing dentition and their prosthetic restoration. The abstracts identified in the respective databases were screened independently by two investigators. RCTs and uncontrolled studies were considered, provided the patients were included consecutively and the confounding variables were adequately monitored. Seventeen papers were included. The study and publication quality was assessed using a “biometric quality” tool showing an overall poor quality. The reported outcomes, such as survival rates, were in each case obtained from a single study. Two possible trends could be deduced for the endpoint longevity: (a the first trend in favor of removable partial dentures, compared to fixed partial dentures, with a fully edentulous opposing arch fitted with a removable prosthesis; (b the second trend in favor of implant-supported partial dentures, compared to conventionally fixed partial dentures, with natural opposing dentition or with a removable partial denture in the opposing arch. No evidence could be generated as to whether, and if so how, variations in the opposing dentition have a bearing on the decision to fit a partially edentulous arch with a fixed or removable partial denture.

INVESTIGATION OF DENTURE REMOVAL PROCESS BY MEANS OF DESTRUCTION OF FIXING CEMENT BY ULTRASOUND ACTION

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M. G. Kiselev

2007-01-01

Full Text Available The paper contains results of experimental investigations in respect of denture removal processes using as models so natural teeth as well and this removal process presupposes destruction of fixing cement by ultrasound action. It has been established that the best conditions for separation of a denture from a tooth body are ensured while ultrasound is acting on non-removable denture structure in liquid phase (water. At the expense of sound-capillary effect water fills in porous structure of fixing cement at high speed and a cavitation that appears in it leads to intensive cement destruction (dispersion.

[Application of individual light-curing resin tray as edge plastic material in complete denture modulo].

Science.gov (United States)

Chai, Mei; Tang, Xuyan; Liang, Guangku

2015-12-01

To investigate clinical effect of individual light-curing resin tray as edge plastic material in complete denture modulo.
 A total of 30 patients with poor condition for alveolar ridge of mandible were chosen individual tray with individual light-curing resin tray for material edge shaping or traditional individual impression tray for edge shaping cream to produce complete denture. The operability, questionnaire about denture retention, comfort, mucosal cases and chewing function in the process of shaping the edge were investigated three months later after wearing dentures.
 There was no significant difference in retention, comfort, mucosa and the chewing function between the two mandibular denture impression methods. However, the patients with individual light-curing resin tray as edge shaping material felt better in the process than that in the patients with die-cream as the edge shaping material (P<0.05). Furthermore, the manipulation with individual light-curing resin tray as edge shaping material is easy for doctor.
 Although the clinical effect of Individual light-curing resin tray material as the edge shaping material is equal to that of impression cream, it saves time and human resource. Moreover, it is more acceptable for the patients and thus it can be spread in clinics.

Clinical evaluation of the essential oil of "Satureja Hortensis" for the treatment of denture stomatitis

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Ali Mohammad Sabzghabaee

2012-01-01

Full Text Available Background: The prevalence of denture stomatitis has been shown to vary from 15 to 65% in complete denture wearers. Satureja hortensis L. has been considered to have antinociceptive, anti-inflammatory, antifungal and antimicrobial activities in vitro and exhibits strong inhibitory effect on the growth of periodontal bacteria. The aim of this study was to evaluate the efficacy of a 1% gel formulation of S. hortensis essential oil for the treatment of denture stomatitis. Materials and Methods: A randomized, controlled clinical trial study was conducted on 80 patients (mean age 62.91±7.34 in two parallel groups treated either with S. hortensis essential oil 1% gel or placebo applied two times daily for two weeks. Denture stomatitis was diagnosed by clinical examination and paraclinical confirmation with sampling the palatal mucosa for Candida albicans. Data were analyzed using Chi-squared or Student′s t tests. Results: The erythematous lesions of palatal area were significantly reduced (P<0.0001 in the treatment group who applied 1% topical gel of S. hortensis essential oil and Candida colonies count were reduced significantly (P=0.001. Conclusion: Topical application of the essential oil of S. hortensis could be considered as an effective agent for the treatment of denture stomatitis.

[Quantitative evaluation of printing accuracy and tissue surface adaptation of mandibular complete denture polylactic acid pattern fabricated by fused deposition modeling technology].

Science.gov (United States)

Deng, K H; Wang, Y; Chen, H; Zhao, Y J; Zhou, Y S; Sun, Y C

2017-06-09

Objective: To quantitatively evaluate the adaptation of polylactic acid (PLA) pattern of mandibular complete denture fabricated by fused deposition modeling (FDM) technology. Methods: A mandibular complete denture digital model was designed through a complete denture design software based on a pair of standard maxillomandibular edentulous plaster model and their occlusion bases. Ten PLA mandibular complete dentures were printed with a FDM machine. The dentures were scanned with and without the plaster model using a three-dimensional (3D) scanner. In Geomagic software, the scanning data of printed dentures were registered to its computer aided design (CAD) data, and the printing error was analyzed using the multipoint registration command. For quantitatively evaluating the adaptation of the denture, the data of plaster model and PLA denture were registered to the whole data of denture located in the plaster model using the best-fit alignment command, the 3D deviation of the plaster model and tissue surface of the denture represent the space between them. The overall area was separated into three parts: primary stress-bearing area, secondary stress-bearing area and border seal area, and the average deviations of these three parts were measured. The values were analyzed using analysis of variance. Results: Compared with the CAD data, the printing error was (0.013±0.004) mm. The overall 3D deviation between PLA denture and plaster model was (0.164±0.033) mm, in which the primary stress-bearing area was (0.165± 0.045) mm, the secondary stress-bearing area was (0.153 ± 0.027) mm, the border seal area was (0.186 ± 0.043) mm. These showed a good fit in the majority parts of the FDM denture to the plaster model. No statistically significant difference was observed between the three areas ( F =1.857, P =0.175>0.05). Conclusions: Combined with the 3D scanning, CAD and FDM technology, a FDM 3D printing process of complete denture for injection moulding can be established

Effect of palatal form on movement of teeth during processing of complete denture prosthesis: An in-vitro study.

Science.gov (United States)

Babu, Sumanth; Manjunath, Shaurya; Vajawat, Mayuri

2016-01-01

The aim of this in-vitro study was to assess the influence of shallow and deep palatal forms on the movement of teeth during the processing of complete denture prosthesis. Maxillary casts with shallow and deep palatal forms were selected and duplicated to make 10 casts of each palatal form. Base plates were constructed and teeth were arranged in their anatomic positions. Metal pins with true apex were placed on the central groove of the right and left first molars and one on the incisive papilla area as a reference point. Casts were scanned using i-CAT Vision Q 1.9 (i-CAT cone beam 3D dental imaging system by Imaging Sciences International, PA, USA), which has 360° rotational tomography. The distances between the apices of metallic pin inserts on the teeth and fitted point of reference were recorded in buccopalatal axes at waxed up stage, after deflasking, and after finishing and polishing. Results showed a statistically significant movement of teeth in shallow and deep palatal forms during all stages of complete denture processing. In shallow palatal form dentures, there was a significant tooth movement in palatal direction between Stages 1 and 2 (P ≤ 0.05) and buccal movement between Stages 2 and 3. In deep palatal form dentures, teeth showed a statistically significant (P ≤ 0.05) movement in buccal direction during all stages of denture processing. Teeth showed significant movement during processing of acrylic resin dentures. Overall, the movement of teeth in shallow palatal form dentures was in palatal direction, whereas in deep palatal form dentures, the movement of teeth was in buccal direction.

Effect of palatal form on movement of teeth during processing of complete denture prosthesis: An in-vitro study

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Sumanth Babu

2016-01-01

Full Text Available Aim: The aim of this in-vitro study was to assess the influence of shallow and deep palatal forms on the movement of teeth during the processing of complete denture prosthesis. Materials and Methods: Maxillary casts with shallow and deep palatal forms were selected and duplicated to make 10 casts of each palatal form. Base plates were constructed and teeth were arranged in their anatomic positions. Metal pins with true apex were placed on the central groove of the right and left first molars and one on the incisive papilla area as a reference point. Casts were scanned using i-CAT Vision Q 1.9 (i-CAT cone beam 3D dental imaging system by Imaging Sciences International, PA, USA, which has 360° rotational tomography. The distances between the apices of metallic pin inserts on the teeth and fitted point of reference were recorded in buccopalatal axes at waxed up stage, after deflasking, and after finishing and polishing. Results: Results showed a statistically significant movement of teeth in shallow and deep palatal forms during all stages of complete denture processing. In shallow palatal form dentures, there was a significant tooth movement in palatal direction between Stages 1 and 2 (P ≤ 0.05 and buccal movement between Stages 2 and 3. In deep palatal form dentures, teeth showed a statistically significant (P ≤ 0.05 movement in buccal direction during all stages of denture processing. Conclusion: Teeth showed significant movement during processing of acrylic resin dentures. Overall, the movement of teeth in shallow palatal form dentures was in palatal direction, whereas in deep palatal form dentures, the movement of teeth was in buccal direction.

Physical and mechanical properties of pressure-molded and injection-molded denture base acrylics in different conditions

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Yousef A Shibat Al Hamd

2014-01-01

Conclusion: The three tested denture base acrylics did not show any significant differences in processing shrinkage. However, ProBase Hot showed significantly lower bending deflection values than Lucitone 199 and SR-Ivocap. Compared to Lucitone 199 and SR-Ivocap, ProBase Hot is a tougher and a stiffer material. Hence, it is more likely to fracture readily if subjected to extreme loading conditions due to the accidental fall of the denture on a hard surface or if the denture wearer inadvertently bites on a particularly hard particle.

Effect of thermal shock on mechanical properties of injection-molded thermoplastic denture base resins.

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Takahashi, Yutaka; Hamanaka, Ippei; Shimizu, Hiroshi

2012-07-01

This study investigated the effect of thermal shock on the mechanical properties of injection-molded thermoplastic denture base resins. Four thermoplastic resins (two polyamides, one polyethylene terephthalate, one polycarbonate) and, as a control, a conventional heat-polymerized polymethyl methacrylate (PMMA), were tested. Specimens of each denture base material were fabricated according to ISO 1567 and were either thermocycled or not thermocycled (n = 10). The flexural strength at the proportional limit (FS-PL), the elastic modulus and the Charpy impact strength of the denture base materials were estimated. Thermocycling significantly decreased the FS-PL of one of the polyamides and the PMMA and it significantly increased the FS-PL of one of the polyamides. In addition, thermocycling significantly decreased the elastic modulus of one of the polyamides and significantly increased the elastic moduli of one of the polyamides, the polyethylene terephthalate, polycarbonate and PMMA. Thermocycling significantly decreased the impact strength of one of the polyamides and the polycarbonate. The mechanical properties of injection-molded thermoplastic denture base resins changed after themocycling.

On cooperative and efficient overlay network evolution based on a group selection pattern.

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Nakao, Akihiro; Wang, Yufeng

2010-04-01

In overlay networks, the interplay between network structure and dynamics remains largely unexplored. In this paper, we study dynamic coevolution between individual rational strategies (cooperative or defect) and the overlay network structure, that is, the interaction between peer's local rational behaviors and the emergence of the whole network structure. We propose an evolutionary game theory (EGT)-based overlay topology evolution scheme to drive a given overlay into the small-world structure (high global network efficiency and average clustering coefficient). Our contributions are the following threefold: From the viewpoint of peers' local interactions, we explicitly consider the peer's rational behavior and introduce a link-formation game to characterize the social dilemma of forming links in an overlay network. Furthermore, in the evolutionary link-formation phase, we adopt a simple economic process: Each peer keeps one link to a cooperative neighbor in its neighborhood, which can slightly speed up the convergence of cooperation and increase network efficiency; from the viewpoint of the whole network structure, our simulation results show that the EGT-based scheme can drive an arbitrary overlay network into a fully cooperative and efficient small-world structure. Moreover, we compare our scheme with a search-based economic model of network formation and illustrate that our scheme can achieve the experimental and analytical results in the latter model. In addition, we also graphically illustrate the final overlay network structure; finally, based on the group selection model and evolutionary set theory, we theoretically obtain the approximate threshold of cost and draw the conclusion that the small value of the average degree and the large number of the total peers in an overlay network facilitate the evolution of cooperation.

Clinical evaluation of isolated abutment teeth in removable partial dentures

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Zarrati S

2011-02-01

Full Text Available "nBackground and Aims: Nowadays, removable partial dentures are applied to patients who are not able to use dental implants or fixed prosthesis. Although based on the studies the users of removable partial dentures are in the risk of plaque accumulation and unacceptable changes such as gingivitis, periodontitis and mobility in abutment tooth. It is not clear whether the negative effects of removable partial dentures are more on the isolated teeth which are a kind of abutment adjacent to endentulous area in both sides. The purpose of this study was to investigate the clinical condition of isolated abutment teeth without splinting in comparison to control abutment from the aspects of B.O.P (bleeding on probing, mobility, pocket depth and gingivitis."nMaterials and Methods: In this cross-sectional study, the prepared questionnaires were filled out by 50 patients who received removable partial dentures in department of removable prosthodontics of dental school of Tehran University of Medical Sciences. The patients had isolated abutment tooth and did not have any systemic disease. The obtained data were analyzed. Using Wilcoxon, exact Fisher and Kruskal-Wallis test."nResults: B.O.P (P=0.004, pocket depth (P=0.035, and mobility (P<0.001 in isolated abutments were more than those in control abutments, but there were not significant differences in the degree of caries (P=0.083 and gingivitis (P=0.07."nConclusion: This study showed that clinical condition of isolated abutments is worse than that of control abutments. More attention should be paid to healthiness of isolated teeth without splinting and periodic follow ups should be done in these cases.

Overlay control methodology comparison: field-by-field and high-order methods

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Huang, Chun-Yen; Chiu, Chui-Fu; Wu, Wen-Bin; Shih, Chiang-Lin; Huang, Chin-Chou Kevin; Huang, Healthy; Choi, DongSub; Pierson, Bill; Robinson, John C.

2012-03-01

Overlay control in advanced integrated circuit (IC) manufacturing is becoming one of the leading lithographic challenges in the 3x and 2x nm process nodes. Production overlay control can no longer meet the stringent emerging requirements based on linear composite wafer and field models with sampling of 10 to 20 fields and 4 to 5 sites per field, which was the industry standard for many years. Methods that have emerged include overlay metrology in many or all fields, including the high order field model method called high order control (HOC), and field by field control (FxFc) methods also called correction per exposure. The HOC and FxFc methods were initially introduced as relatively infrequent scanner qualification activities meant to supplement linear production schemes. More recently, however, it is clear that production control is also requiring intense sampling, similar high order and FxFc methods. The added control benefits of high order and FxFc overlay methods need to be balanced with the increased metrology requirements, however, without putting material at risk. Of critical importance is the proper control of edge fields, which requires intensive sampling in order to minimize signatures. In this study we compare various methods of overlay control including the performance levels that can be achieved.

Influence of one- or two-stage methods for polymerizing complete dentures on adaptation and teeth movements

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Moises NOGUEIRA

Full Text Available Abstract Introduction The quality of complete dentures might be influenced by the method of confection. Objective To evaluate the influence of two different methods of processing muco-supported complete dentures on their adaptation and teeth movements. Material and method Denture confection was assigned in two groups (n=10 for upper and lower arches according to polymerization method: 1 conventional one-stage - a wax trial base was made, teeth were arranged and polymerized; 2 two-stage method - the base was waxed and first polymerized. With the denture base polymerized, the teeth were arranged and then, performed the final polymerization. Teeth movements were evaluated in the distances between incisive (I-I, pre-molars (P-P, molars (M-M, left incisor to left molar (LI-LM and right incisor to right molar (RI-RM. For the adaptation analysis, dentures were cut in three different positions: (A distal face of canines, (B mesial face of the first molars, and (C distal face of second molars. Result Denture bases have shown a significant better adaptation when polymerized in the one-stage procedure for both the upper (p=0.000 and the lower (p=0.000 arches, with region A presenting significant better adaptation than region C. In the upper arch, significant reduction in the distance between I-I was observed in the one-stage technique, while the two-stage technique promoted significant reduction in the RI-RM distance. In the lower arch, one-stage technique promoted significant reduction in the distance for RI-RM and two-stage promoted significant reduction in the LI-LM distance. Conclusion Conventional one-stage method presented the better results for denture adaptation. Both fabrication methods presented some alteration in teeth movements.

Faster diffraction-based overlay measurements with smaller targets using 3D gratings

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Li, Jie; Kritsun, Oleg; Liu, Yongdong; Dasari, Prasad; Volkman, Catherine; Hu, Jiangtao

2012-03-01

Diffraction-based overlay (DBO) technologies have been developed to address the overlay metrology challenges for 22nm technology node and beyond. Most DBO technologies require specially designed targets that consist of multiple measurement pads, which consume too much space and increase measurement time. The traditional empirical approach (eDBO) using normal incidence spectroscopic reflectometry (NISR) relies on linear response of the reflectance with respect to overlay displacement within a small range. It offers convenience of quick recipe setup since there is no need to establish a model. However it requires three or four pads per direction (x or y) which adds burden to throughput and target size. Recent advances in modeling capability and computation power enabled mDBO, which allows overlay measurement with reduced number of pads, thus reducing measurement time and DBO target space. In this paper we evaluate the performance of single pad mDBO measurements using two 3D targets that have different grating shapes: squares in boxes and L-shapes in boxes. Good overlay sensitivities are observed for both targets. The correlation to programmed shifts and image-based overlay (IBO) is excellent. Despite the difference in shapes, the mDBO results are comparable for square and L-shape targets. The impact of process variations on overlay measurements is studied using a focus and exposure matrix (FEM) wafer. Although the FEM wafer has larger process variations, the correlation of mDBO results with IBO measurements is as good as the normal process wafer. We demonstrate the feasibility of single pad DBO measurements with faster throughput and smaller target size, which is particularly important in high volume manufacturing environment.

An Investigation into the Trueness and Precision of Copy Denture Templates Produced by Rapid Prototyping and Conventional Means.

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Davda, K; Osnes, C; Dillon, S; Wu, J; Hyde, P; Keeling, A

2017-12-01

To assess the trueness and precision of copy denture templates produced using traditional methods and 3D printing. Six copies of a denture were made using: 1. Conventional technique with silicone putty in an impression tray (CT). 2. Conventional technique with no impression tray (CNT). 3. 3D scanning and printing (3D). Scan trueness and precision was investigated by scanning a denture six times and comparing five scans to the sixth. Then the scans of the six CT, CNT and 3D dentures were compared by aligning, in turn, the copies of each denture to the scanned original. Outcome measures were the mean surface-to-surface distance, standard deviation of that distance and the maximum distance. Student's unpaired t-tests with Bonferroni correction were used to analyse the results. The repeated scans of the original denture showed a scan trueness of 0.013mm (SD 0.002) and precision of 0.013mm (SD 0.002). Trueness: CT templates, 0.168mm (0.047), CNT templates 0.195mm (0.034) and 3D 0.103mm (0.021). Precision: CT templates 0.158mm (0.037), CNT 0.233mm (0.073), 3D 0.090mm (0.017). For each outcome measure the 3D templates demonstrated an improvement which was statistically significant (p⟨0.05). 3D printed copy denture templates reproduced the original with greater trueness and precision than conventional techniques. Copyright© 2017 Dennis Barber Ltd.

Novel denture-cleaning system based on hydroxyl radical disinfection.

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Kanno, Taro; Nakamura, Keisuke; Ikai, Hiroyo; Hayashi, Eisei; Shirato, Midori; Mokudai, Takayuki; Iwasawa, Atsuo; Niwano, Yoshimi; Kohno, Masahiro; Sasaki, Keiichi

2012-01-01

The purpose of this study was to evaluate a new denture-cleaning device using hydroxyl radicals generated from photolysis of hydrogen peroxide (H2O2). Electron spin resonance analysis demonstrated that the yield of hydroxyl radicals increased with the concentration of H2O2 and light irradiation time. Staphylococcus aureus, Pseudomonas aeruginosa, and methicillin-resistant S aureus were killed within 10 minutes with a > 5-log reduction when treated with photolysis of 500 mM H2O2; Candida albicans was killed within 30 minutes with a > 4-log reduction with photolysis of 1,000 mM H2O2. The clinical test demonstrated that the device could effectively reduce microorganisms in denture plaque by approximately 7-log order within 20 minutes.

Driving imaging and overlay performance to the limits with advanced lithography optimization

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Mulkens, Jan; Finders, Jo; van der Laan, Hans; Hinnen, Paul; Kubis, Michael; Beems, Marcel

2012-03-01

Immersion lithography is being extended to 22-nm and even below. Next to generic scanner system improvements, application specific solutions are needed to follow the requirements for CD control and overlay. Starting from the performance budgets, this paper discusses how to improve (in volume manufacturing environment) CDU towards 1-nm and overlay towards 3-nm. The improvements are based on deploying the actuator capabilities of the immersion scanner. The latest generation immersion scanners have extended the correction capabilities for overlay and imaging, offering freeform adjustments of lens, illuminator and wafer grid. In order to determine the needed adjustments the recipe generation per user application is based on a combination wafer metrology data and computational lithography methods. For overlay, focus and CD metrology we use an angle resolved optical scatterometer.

The effect of full denture on memory and depression status in elderly

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Bahruddin Thalib

2016-06-01

Full Text Available Complaint that is most often found in elderly is declining or disappearing memory and tooth loss due to aging. Loss of teeth will cause a disturbance in the function of mastication and reportedly may also contribute to the occurrence of memory disorders and depression. The objective of this study was to analyze the influence of full denture use on memory capacity and depression level in elderly. Study conducted at Oral and Dental Hospital Faculty of Dentistry, University of Hasanuddin. This study was clinical experimental with non-randomized design with pre and post test. Sampling with purposive sampling technique, and there were 6 people who are willing to participate. Memory status measurement using Mini-Mental State Exam (MMSE and level of depression using Geriatric Depression Scale (GDS. Memory status and level of depression measurement performed before using full denture and one month after using full denture. Data were analyzed with statistical pair T-test. With a 95% confidence level, the results showed there is an increase in initial MMSE average value (25.67 to the final MMSE average value (26.83 with statistically significant effect, p 0,05. This study concluded that there was significant influence in using full denture on improved memory status of complete edentulous elderly, and despite there were decreased on level of depression, but it was not statistically significant.

A radiographic template for a two-implant mandibular overdenture using the patient’s existing denture

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Huynh-Ba, G; Alexander, P; Vargas, A; Vierra, M; Oates, TW

2012-01-01

This article introduces a technique for modifying an existing mandibular complete denture for use as a radiographic template with a radiopaque light-activated calcium hydroxide (Ca(OH)2) preparation. This allows prosthetically-driven treatment planning and surgical placement of 2 implants to support the existing mandibular denture. PMID:23328197

A study of swing-curve physics in diffraction-based overlay

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Bhattacharyya, Kaustuve; den Boef, Arie; Storms, Greet; van Heijst, Joost; Noot, Marc; An, Kevin; Park, Noh-Kyoung; Jeon, Se-Ra; Oh, Nang-Lyeom; McNamara, Elliott; van de Mast, Frank; Oh, SeungHwa; Lee, Seung Yoon; Hwang, Chan; Lee, Kuntack

2016-03-01

With the increase of process complexity in advanced nodes, the requirements of process robustness in overlay metrology continues to tighten. Especially with the introduction of newer materials in the film-stack along with typical stack variations (thickness, optical properties, profile asymmetry etc.), the signal formation physics in diffraction-based overlay (DBO) becomes an important aspect to apply in overlay metrology target and recipe selection. In order to address the signal formation physics, an effort is made towards studying the swing-curve phenomena through wavelength and polarizations on production stacks using simulations as well as experimental technique using DBO. The results provide a wealth of information on target and recipe selection for robustness. Details from simulation and measurements will be reported in this technical publication.

[Principles of bone tissue structures interaction with full removable dentures fixed on intraosseous implantates modelling].

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Shashmurina, V R; Chumachenko, E N; Olesova, V N; Volozhin, A I

2008-01-01

Math modelling "removable dentures-implantate-bone" with size and density of bone tissue as variables was created. It allowed to study biomechanical bases of mandibular bone tissue structures interaction with full removable dentures of different constructions and fixed on intraosseous implantates. Analysis of the received data showed that in the majority of cases it was expedient to recommend 3 bearing (abutments) system of denture making. Rest on 4 and more implantates was appropriate for patients with reduced density of spongy bone and significant mandibular bone atrophy. 2 abutment system can be used in patients with high density of spongy bone and absence of mandibular bone atrophy.

Duplication of complete dentures using general-purpose handheld optical scanner and 3-dimensional printer: Introduction and clinical considerations.

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Kurahashi, Kosuke; Matsuda, Takashi; Goto, Takaharu; Ishida, Yuichi; Ito, Teruaki; Ichikawa, Tetsuo

2017-01-01

To introduce a new clinical procedure for fabricating duplicates of complete dentures by bite pressure impression using digital technology, and to discuss its clinical significance. The denture is placed on a rotary table and the 3-dimensional form of the denture is digitized using a general-purpose handheld optical scanner. The duplicate denture is made of polylactic acid by a 3-dimensional printer using the 3-dimensional data. This procedure has the advantages of wasting less material, employing less human power, decreasing treatment time at the chair side, lowering the rates of contamination, and being readily fabricated at the time of the treatment visit. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

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

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Jensen-Louwerse, C

2017-06-01

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

Radio frequency identification (RFID) of dentures in long-term care facilities.

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Madrid, Carlos; Korsvold, Tové; Rochat, Aline; Abarca, Marcelo

2012-03-01

The difficulty of identifying the ownership of lost dentures when found is a common and expensive problem in long term care facilities (LTCFs) and hospitals. The purpose of this study was to evaluate the reliability of using radiofrequency identification (RFID) in the identification of dentures for LTCF residents after 3 and 6 months. Thirty-eight residents of 2 LTCFs in Switzerland agreed to participate after providing informed consent. The tag was programmed with the family and first names of the participants and then inserted in the dentures. After placement of the tag, the information was read. A second and third assessment to review the functioning of the tag occurred at 3 and 6 months, and defective tags (if present) were reported and replaced. The data were analyzed with descriptive statistics. At the 3-month assessment of 34 residents (63 tags) 1 tag was unreadable and 62 tags (98.2%) were operational. At 6 months, the tags of 27 of the enrolled residents (50 tags) were available for review. No examined tag was defective at this time period. Within the limits of this study (number of patients, 6-month time span) RFID appears to be a reliable method of tracking and identifying dentures, with only 1 of 65 devices being unreadable at 3 months and 100% of 50 initially placed tags being readable at the end of the trial. Copyright © 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

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

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

2017-08-01

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

Simultaneous overlay and CD measurement for double patterning: scatterometry and RCWA approach

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Li, Jie; Liu, Zhuan; Rabello, Silvio; Dasari, Prasad; Kritsun, Oleg; Volkman, Catherine; Park, Jungchul; Singh, Lovejeet

2009-03-01

As optical lithography advances to 32 nm technology node and beyond, double patterning technology (DPT) has emerged as an attractive solution to circumvent the fundamental optical limitations. DPT poses unique demands on critical dimension (CD) uniformity and overlay control, making the tolerance decrease much faster than the rate at which critical dimension shrinks. This, in turn, makes metrology even more challenging. In the past, multi-pad diffractionbased overlay (DBO) using empirical approach has been shown to be an effective approach to measure overlay error associated with double patterning [1]. In this method, registration errors for double patterning were extracted from specially designed diffraction targets (three or four pads for each direction); CD variation is assumed negligible within each group of adjacent pads and not addressed in the measurement. In another paper, encouraging results were reported with a first attempt at simultaneously extracting overlay and CD parameters using scatterometry [2]. In this work, we apply scatterometry with a rigorous coupled wave analysis (RCWA) approach to characterize two double-patterning processes: litho-etch-litho-etch (LELE) and litho-freeze-litho-etch (LFLE). The advantage of performing rigorous modeling is to reduce the number of pads within each measurement target, thus reducing space requirement and improving throughput, and simultaneously extract CD and overlay information. This method measures overlay errors and CDs by fitting the optical signals with spectra calculated from a model of the targets. Good correlation is obtained between the results from this method and that of several reference techniques, including empirical multi-pad DBO, CD-SEM, and IBO. We also perform total measurement uncertainty (TMU) analysis to evaluate the overall performance. We demonstrate that scatterometry provides a promising solution to meet the challenging overlay metrology requirement in DPT.

VMCast: A VM-Assisted Stability Enhancing Solution for Tree-Based Overlay Multicast.

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Weidong Gu

Full Text Available Tree-based overlay multicast is an effective group communication method for media streaming applications. However, a group member's departure causes all of its descendants to be disconnected from the multicast tree for some time, which results in poor performance. The above problem is difficult to be addressed because overlay multicast tree is intrinsically instable. In this paper, we proposed a novel stability enhancing solution, VMCast, for tree-based overlay multicast. This solution uses two types of on-demand cloud virtual machines (VMs, i.e., multicast VMs (MVMs and compensation VMs (CVMs. MVMs are used to disseminate the multicast data, whereas CVMs are used to offer streaming compensation. The used VMs in the same cloud datacenter constitute a VM cluster. Each VM cluster is responsible for a service domain (VMSD, and each group member belongs to a specific VMSD. The data source delivers the multicast data to MVMs through a reliable path, and MVMs further disseminate the data to group members along domain overlay multicast trees. The above approach structurally improves the stability of the overlay multicast tree. We further utilized CVM-based streaming compensation to enhance the stability of the data distribution in the VMSDs. VMCast can be used as an extension to existing tree-based overlay multicast solutions, to provide better services for media streaming applications. We applied VMCast to two application instances (i.e., HMTP and HCcast. The results show that it can obviously enhance the stability of the data distribution.

Effects of Spectral Overlays on Reading Performance of Brazilian Elementary School Children.

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Garcia, Ana Carla Oliveira; Momensohn-Santos, Teresa Maria; Vilhena, Douglas de Araújo

2018-03-20

To investigate the effects of spectral overlays on reading performance of Brazilian elementary school children. Sixty-eight children (aged 9-12 years) enrolled in the 5th and 6th grade were included in the study. The Rate of Reading Test (RRT - Brazilian Portuguese version) was used to evaluate reading speed and the Irlen Reading Perceptual Scale was used to allocate the sample according to reading difficulty/discomfort symptoms and to define the optimal spectral overlays. A total of 13% of the children presented an improvement of at least 15% in reading speed with the use of spectral overlays. Pupils with severe reading difficulties tended to have more improvement in RRT with spectral overlays. Children with severe reading discomfort obtained the highest gains in RRT, with an average of 9.6% improvement with intervention, compared to a decrease of -8.2% in the control group. Participants with severe discomfort had an odds ratio of 3.36 to improve reading speed with intervention compared to the control group. The use of spectral overlays can improve reading performance, particularly in those children with severe visual discomfort. © 2018 S. Karger AG, Basel.

Implant-supported removable partial dentures in the mandible

NARCIS (Netherlands)

Louwerse, Charlotte

2017-01-01

Conventional removable partial dentures (RPD) in a free-ending situation in the lower jaw (i.e. only front teeth left) have a poor reputation. Several problems like discomfort and functional problems are frequently encountered, resulting in dissatisfied patients and desperate dentists. By supporting

Determining color difference thresholds in denture base acrylic resin.

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Ren, Jiabao; Lin, Hong; Huang, Qingmei; Zheng, Gang

2015-11-01

In restorative prostheses, color is important, but the choice of color difference formula used to quantify color change in acrylic resins is not straightforward. The purpose of this in vitro study was to choose a color difference formula that best represented differences between the calculated color and the observed imperceptible to unacceptable color and to determine the corresponding perceptibility and acceptability threshold of color stability for denture base acrylic resins. A total of 291 acrylic resin denture base plates were fabricated and subjected to radiation tests from zero to 42 hours in accordance with ISO 7491:2000. Color was measured with a portable spectrophotometer, and color differences were calculated with 3 International Commission on Illumination (CIE) formulas: CIELab, CMC(1:1), and CIEDE2000. Thirty-four observers with no deficiencies in color perception participated in psychophysical perceptibility and acceptability assessments under controlled conditions in vitro. These 2 types of assessments were regressed to each observer by each formula to generate receiver operator characteristic (ROC) curves. Areas under the curves (AUCs) were then calculated and analyzed to exclude observers with poor color discrimination. AUCs were subjected to 1-way ANOVA (α=.05) to deter the statistical significance of discriminability among the 3 formulas in terms of perceptibility and acceptability judgments. Student-Newman-Keuls tests (α=.05) were used for post hoc comparison. CMC(1:1) and CIEDE2000 formulas performed better for imperceptible to unacceptable color differences, with corresponding CMC(1:1) and CIEDE2000 values for perceptibility of 2.52 and 1.72, respectively, and acceptability thresholds of 6.21 and 4.08, respectively. Formulas CMC(1:1) and CIEDE2000 possess higher discriminability than that of CIELab in the assessment of perceptible color difference threshold of denture base acrylic resin. A statistically significant difference exists

Holistic metrology qualification extension and its application to characterize overlay targets with asymmetric effects

Science.gov (United States)

Dos Santos Ferreira, Olavio; Sadat Gousheh, Reza; Visser, Bart; Lie, Kenrick; Teuwen, Rachel; Izikson, Pavel; Grzela, Grzegorz; Mokaberi, Babak; Zhou, Steve; Smith, Justin; Husain, Danish; Mandoy, Ram S.; Olvera, Raul

2018-03-01

Ever increasing need for tighter on-product overlay (OPO), as well as enhanced accuracy in overlay metrology and methodology, is driving semiconductor industry's technologists to innovate new approaches to OPO measurements. In case of High Volume Manufacturing (HVM) fabs, it is often critical to strive for both accuracy and robustness. Robustness, in particular, can be challenging in metrology since overlay targets can be impacted by proximity of other structures next to the overlay target (asymmetric effects), as well as symmetric stack changes such as photoresist height variations. Both symmetric and asymmetric contributors have impact on robustness. Furthermore, tweaking or optimizing wafer processing parameters for maximum yield may have an adverse effect on physical target integrity. As a result, measuring and monitoring physical changes or process abnormalities/artefacts in terms of new Key Performance Indicators (KPIs) is crucial for the end goal of minimizing true in-die overlay of the integrated circuits (ICs). IC manufacturing fabs often relied on CD-SEM in the past to capture true in-die overlay. Due to destructive and intrusive nature of CD-SEMs on certain materials, it's desirable to characterize asymmetry effects for overlay targets via inline KPIs utilizing YieldStar (YS) metrology tools. These KPIs can also be integrated as part of (μDBO) target evaluation and selection for final recipe flow. In this publication, the Holistic Metrology Qualification (HMQ) flow was extended to account for process induced (asymmetric) effects such as Grating Imbalance (GI) and Bottom Grating Asymmetry (BGA). Local GI typically contributes to the intrafield OPO whereas BGA typically impacts the interfield OPO, predominantly at the wafer edge. Stack height variations highly impact overlay metrology accuracy, in particular in case of multi-layer LithoEtch Litho-Etch (LELE) overlay control scheme. Introducing a GI impact on overlay (in nm) KPI check quantifies the

The Antifungal Activity and Cytotoxicity of Silver Containing Denture ...

African Journals Online (AJOL)

2015-10-30

Oct 30, 2015 ... Objective: Denture base materials are susceptible to fungal adhesion, which is an important .... (Shimadzu Corp., Kyoto, Japan) to achieve a wavelength ..... assay for detection of cytotoxicity and prediction of acute toxicity.

Effectiveness of polymer bridge deck overlays in highway noise reduction : technical paper.

Science.gov (United States)

2016-04-01

The Kansas Department of Transportation (KDOT) began placing multi-layer polymer bridge deck overlays in 1999 and at the present time have over 200 in service. A few years after placing the overlays, individuals indicated that they noticed how quiet ...

Telescopic Partial Dentures-Concealed Technology

OpenAIRE

Bhagat, Tushar Vitthalrao; Walke, Ashwini Nareshchandra

2015-01-01

The ideal goal of good dentist is to restore the missing part of oral structure, phonetics, his look and the most important is restored the normal health of the patient, which is hampered due to less or insufficient intake of food. Removable partial denture (RPD) treatment option is considered as a notion, which precludes the inevitability of ?floating plastic? in edentulous mouth, that many times fail to fulfill the above essential of the patients. In modern dentistry, though the dental impl...

Dual Component Removable Partial Denture shows improved ...

African Journals Online (AJOL)

Dual Component Removable Partial Denture (DuCo RPD) is composed of a double base; lower and upper. The lower base, where the artificial teeth are attached, acts as a support and is in contact with the alveolar ridges and oral mucosa. Clasps are designed on the upper base, which acts towards the retention and ...

Prospective cohort pilot study of 2-visit CAD/CAM monolithic complete dentures and implant-retained overdentures: Clinical and patient-centered outcomes.

Science.gov (United States)

Bidra, Avinash S; Farrell, Kimberly; Burnham, David; Dhingra, Ajay; Taylor, Thomas D; Kuo, Chia-Ling

2016-05-01

Presently, no studies have evaluated clinical outcomes or patient-centered outcomes for complete dentures fabricated with computer-aided design and computer aided manufacturing (CAD/CAM) technology. The purpose of this prospective cohort pilot study was to evaluate the clinical and patient-centered outcomes for CAD/CAM monolithic dentures fabricated in 2 visits. Twenty participants with an existing set of maxillary complete dentures opposing either mandibular complete dentures or implant-retained overdentures that required replacement were recruited in this study. A 2-visit duplicate denture protocol was used to fabricate 40 arches of monolithic dentures with CAD/CAM technology. A 100-mm visual analog scale (VAS) instrument was then used to record 12 outcomes at baseline and at 1-year follow-up. Predetermined values were assigned to grade the VAS rating of each outcome as favorable (70.1-100) and unfavorable (≤70). Favorable ratings were sub-divided as excellent (90.1-100), good (80.1-90), and fair (70.1-80). The clinical outcomes were evaluated independently by 2 experienced prosthodontists at baseline and at 1-year follow-up. Patients evaluated the corresponding patient-centered outcomes during the same time intervals. Additional descriptive variables were also recorded. Each clinical and patient-centered outcome was summarized by medians and ranges. Differences in all ratings recorded at baseline and at 1 year were tested by 1-sided sign test (α=.05). Of 20 participants, 3 were lost to follow-up, and 3 were unsatisfied with the digital dentures and withdrew from the study. These 3 participants were considered treatment failures. Of the 14 remaining participants, 9 had implant-retained mandibular overdentures, and 5 had conventional mandibular complete dentures. For clinical outcomes, the 12 studied outcomes were favorably evaluated by the 2 prosthodontist judges at the 1-year follow-up. Evaluations showed minimal differences between baseline and 1 year. An

Clinical application of removable partial dentures using thermoplastic resin. Part II: Material properties and clinical features of non-metal clasp dentures.

Science.gov (United States)

Fueki, Kenji; Ohkubo, Chikahiro; Yatabe, Masaru; Arakawa, Ichiro; Arita, Masahiro; Ino, Satoshi; Kanamori, Toshikazu; Kawai, Yasuhiko; Kawara, Misao; Komiyama, Osamu; Suzuki, Tetsuya; Nagata, Kazuhiro; Hosoki, Maki; Masumi, Shin-ichi; Yamauchi, Mutsuo; Aita, Hideki; Ono, Takahiro; Kondo, Hisatomo; Tamaki, Katsushi; Matsuka, Yoshizo; Tsukasaki, Hiroaki; Fujisawa, Masanori; Baba, Kazuyoshi; Koyano, Kiyoshi; Yatani, Hirofumi

2014-04-01

This position paper reviews physical and mechanical properties of thermoplastic resin used for non-metal clasp dentures, and describes feature of each thermoplastic resin in clinical application of non-metal clasp dentures and complications based on clinical experience of expert panels. Since products of thermoplastic resin have great variability in physical and mechanical properties, clinicians should utilize them with careful consideration of the specific properties of each product. In general, thermoplastic resin has lower color-stability and higher risk for fracture than polymethyl methacrylate. Additionally, the surface of thermoplastic resin becomes roughened more easily than polymethyl methacrylate. Studies related to material properties of thermoplastic resin, treatment efficacy and follow-up are insufficient to provide definitive conclusions at this time. Therefore, this position paper should be revised based on future studies and a clinical guideline should be provided. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Biofilm development by blastospores and hyphae of Candida albicans on abraded denture acrylic resin surfaces.

Science.gov (United States)

Jackson, Sarah; Coulthwaite, Lisa; Loewy, Zvi; Scallan, Anthony; Verran, Joanna

2014-10-01

Candida albicans is a known etiologic agent of denture stomatitis. Candida hyphae exhibit the ability to respond directionally to environmental stimuli. This characteristic is thought to be important in the penetration of substrata such as resilient denture liners and host epithelium. It has been suggested that hyphal production also enhances adhesion and survival of Candida on host and denture surfaces. Surface roughness, in addition, can enhance adhesion where stronger interactions occur between cells and surface features of similar dimensions. The purpose of this study was to assess the development of hyphal and blastospore biofilms on abraded denture acrylic resin specimens and measure the ease of removal of these biofilms. Biofilms were grown for 48 hours on abraded 1-cm² denture acrylic resin specimens from adhered hyphal phase C albicans or from adhered blastospores. Subsequently, all specimens were stained with Calcofluor White and examined with confocal scanning laser microscopy. Biofilms were removed by vortex mixing in sterile phosphate buffered saline solution. Removed cells were filtered (0.2-μm pore size). Filters were dried at 37°C for 24 hours for dry weight measurements. Any cells that remained on the acrylic resin specimens were stained with 0.03% acridine orange and examined with epifluorescence microscopy. Biofilms grown from both cell types contained all morphologic forms of C albicans. Although the underlying surface topography did not affect the amount of biofilm produced, biofilms grown from hyphal phase Candida were visibly thicker and had greater biomass (Phyphae in early Candida biofilms increased biofilm mass and resistance to removal. Increased surface roughness enhances retention of hyphae and yeast cells, and, therefore, will facilitate plaque regrowth. Therefore, minimization of denture abrasion during cleaning is desirable. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All

Patient satisfaction with occlusal scheme of conventional complete dentures: A randomised clinical trial (part I).

Science.gov (United States)

Moradpoor, H; Arabzade Hoseini, M; Savabi, O; Shirani, M

2018-01-01

Occlusal scheme can affect denture retention, stability, occlusal force distribution, aesthetics, masticatory function, patient comfort and general patient satisfaction with dentures. This study aimed to compare the patient satisfaction with 3 types of complete denture occlusion including fully bilateral balanced occlusion (FBBO), newly presented buccalised occlusion (BO) and lingualised occlusion (LO). In this parallel randomised clinical trial, new conventional complete dentures were fabricated for 86 volunteers. Participants were randomly allocated to 3 groups with 3 different occlusal schemes. All patients were recalled at 1 and 3 months after delivery for data collection. The 19-item version of Oral Health Impact Profile for Edentulous Patients questionnaire was used in this study. The visual analogue scale (VAS) was used for assessment of the prosthodontist's attitude towards denture quality, patient's attitude towards different occlusal schemes and evaluation of patient satisfaction. Data were analysed using the Wilcoxon signed rank test, the Kruskal-Wallis test and the post hoc Dunn test via SPSS version 18.0 (P ≤ .05). Eighty-six patients completed the study, and their data were analysed (mean age ± standard deviation = 57.78 ± 9.98 years). The only significant difference when comparing the 3 groups was physical pain, which was significantly higher in FBBO group. No significant differences were found for the VAS scores of patient and prosthodontist satisfaction or the domain scores among the 3 occlusal schemes either at 1 or at 3 months post-delivery. The VAS score of patient satisfaction and prosthodontist satisfaction increased at third compared to first month after delivery. The results of this randomised clinical trial provided evidence that BO is as effective as LO for the fabrication of complete dentures. © 2017 John Wiley & Sons Ltd.

Denture acceptance among newly rehabilitated elderly population in old age homes in South India

Directory of Open Access Journals (Sweden)

Mallika S Shetty

2015-01-01

Full Text Available Introduction: Elders in old age homes are mainly those who have been abandoned by their family and have one or more physical or mental disabilities. It is a major challenge for the dental professional to plan oral health strategy for this group of patients. Aim of the Study: Aim of the present study is to observe and determine the acceptance of new dental prosthesis among the elderly residing as inmates of 3 old age homes in Mangalore City. Materials and Methods: This cross-sectional study was conducted using a survey proforma. Information regarding their experience with the new denture, 1-month, 3 months and 6 months after denture insertion was gathered. Statistical analysis of the data was done using the Chi-square test with the P < 0.05 considered significant. Results: One hundred and eighty-three residents out of a total of 400 residents in 3 old age homes were denture wearers. Among them, 101 (55.2% were females, and 82 (44.8% were males. Dental prosthesis whether worn regularly, discomfort, retention, cleansing of denture during a period of 1-month, 3 months and 6 months was found to be significant satisfaction with the prosthesis, denture adhesives used, food accumulation during a period of 1-month, 3 months and 6 months was found to be nonsignificant. Conclusion: The emotional makeup of the patient must be taken into consideration during the entire procedure. We must understand that the success of the prosthesis depends mainly on the patient′s confidence in the dentist rather than the quality of the prosthesis.

Intermittent-contact scanning capacitance microscopy imaging and modeling for overlay metrology

International Nuclear Information System (INIS)

Mayo, S.; Kopanski, J. J.; Guthrie, W. F.

1998-01-01

Overlay measurements of the relative alignment between sequential layers are one of the most critical issues for integrated circuit (IC) lithography. We have implemented on an AFM platform a new intermittent-contact scanning capacitance microscopy (IC-SCM) mode that is sensitive to the tip proximity to an IC interconnect, thus making it possible to image conductive structures buried under planarized dielectric layers. Such measurements can be used to measure IC metal-to-resist lithography overlay. The AFM conductive cantilever probe oscillating in a vertical plane was driven at frequency ω, below resonance. By measuring the tip-to-sample capacitance, the SCM signal is obtained as the difference in capacitance, ΔC(ω), at the amplitude extremes. Imaging of metallization structures was obtained with a bars-in-bars aluminum structure embedded in a planarized dielectric layer 1 μm thick. We have also modeled, with a two-dimensional (2D) electrostatic field simulator, IC-SCM overlay data of a metallization structure buried under a planarized dielectric having a patterned photoresist layer deposited on it. This structure, which simulates the metal-to-resist overlay between sequential IC levels, allows characterization of the technique sensitivity. The capacitance profile across identical size electrically isolated or grounded metal lines embedded in a dielectric was shown to be different. The floating line shows capacitance enhancement at the line edges, with a minimum at the line center. The grounded line shows a single capacitance maximum located at the line center, with no edge enhancement. For identical line dimensions, the capacitance is significantly larger for grounded lines making them easier to image. A nonlinear regression algorithm was developed to extract line center and overlay parameters with approximately 3 nm resolution at the 95% confidence level, showing the potential of this technique for sub-micrometer critical dimension metrology. Symmetric test

Social determinants of denture/bridge use: Japan gerontological evaluation study project cross-sectional study in older Japanese.

Science.gov (United States)

Yamamoto, Tatsuo; Kondo, Katsunori; Aida, Jun; Suzuki, Kayo; Misawa, Jimpei; Nakade, Miyo; Fuchida, Shinya; Hirata, Yukio

2014-06-03

Studies suggest that using a denture/bridge may prevent disability in older people. However, not all older people with few remaining teeth use a denture/bridge. This cross-sectional study aimed to examine the social determinants which promote denture/bridge use among older Japanese. A total of 54,388 (25,630 males and 28,758 females) community-dwelling individuals aged 65 or over, living independently, able to perform daily activities, and with 19 or fewer teeth. The dependent variable was denture/bridge use. Socio-demographics, number of teeth, present illness, social participation, social support, and social networks were used as individual-level independent variables. Data for social capital were aggregated and used as local district (n = 561 for males, n = 562 for females) -level independent variables. Number of dentists working in hospitals/clinics per population and population density were used as municipality (n = 28) -level independent variables. Three-level multilevel Poisson regression analysis was performed for each sex. High equivalent income, low number of teeth, present illness, and living in a municipality with high population density were significantly associated with denture/bridge use in both sexes in the fully adjusted models (p social groups in females in the fully adjusted model (p social capital. Denture/bridge use was significantly associated with high economic status and present illness in both sexes, high educational attainment in males, and participation in social groups in females among community-dwelling older Japanese after adjusting for possible confounders.

Solidification paths in modified Inconel 625 weld overlay material

DEFF Research Database (Denmark)

Chandrasekaran, Karthik; Tiedje, Niels Skat; Hald, John

2009-01-01

Inconel 625 is commonly used for overlay welding to protect the base metal against high temperature corrosion. The efficiency of corrosion protection depends on effective mixing of the overlay weld with the base metal and the subsequent segregation of alloy elements during solidification....... Metallographic analysis of solidified samples of Inconel 625 with addition of selected elements is compared with thermodynamic modelling of segregation during solidification. The influence of changes in the melt chemistry on the formation of intermetallic phases during solidification is shown. In particular...

Dynamics of a metal overlayer on metallic substrates: High temperature effects

International Nuclear Information System (INIS)

Rahman, T.S.; Black, J.E.; Tian, Zeng Ju

1992-01-01

We have explored the structure and the dynamics of a bimetallic system consisting of a hexagonal (almost) overlayer of Ag on a square lattice (Ni(100) and Cu(100)), as a function of the surface temperature. In each case the structure is ''nearly'' incommensurate giving rise to a low frequency Goldstone mode. Also, the overlayer atoms slosh back and forth over the substrate in a corrugated fashion. The calculated dispersion of the Ag/metal vertical mode, at room temperature, is in excellent agreement with experimental data. At higher temperatures floater atoms appear on top of the overlayer displaying a variety of cluster formations and also exchanges with the substrate atoms leading to surface disordering, interdiffusion and melting

Complete Dentures Fabricated with CAD/CAM Technology and a Traditional Clinical Recording Method.

Science.gov (United States)

Janeva, Nadica; Kovacevska, Gordana; Janev, Edvard

2017-10-15

The introduction of computer-aided design/computer-aided manufacturing (CAD/CAM) technology into complete denture (CD) fabrication ushered in a new era in removable prosthodontics. Commercially available CAD/CAM denture systems are expected to improve upon the disadvantages associated with conventional fabrication. The purpose of this report is to present the workflow involved in fabricating a CD with a traditional clinical recording method and CAD/CAM technology and to summarize the advantages to the dental practitioner and the patient.

Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA.

Science.gov (United States)

Qamheya, Ala Hassan A; Yeniyol, Sinem; Arısan, Volkan

2015-01-01

Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC) material in teeth construction to rehabilitate a complete denture wearer patient.

Multi-wavelength approach towards on-product overlay accuracy and robustness

Science.gov (United States)

Bhattacharyya, Kaustuve; Noot, Marc; Chang, Hammer; Liao, Sax; Chang, Ken; Gosali, Benny; Su, Eason; Wang, Cathy; den Boef, Arie; Fouquet, Christophe; Huang, Guo-Tsai; Chen, Kai-Hsiung; Cheng, Kevin; Lin, John

2018-03-01

Success of diffraction-based overlay (DBO) technique1,4,5 in the industry is not just for its good precision and low toolinduced shift, but also for the measurement accuracy2 and robustness that DBO can provide. Significant efforts are put in to capitalize on the potential that DBO has to address measurement accuracy and robustness. Introduction of many measurement wavelength choices (continuous wavelength) in DBO is one of the key new capabilities in this area. Along with the continuous choice of wavelengths, the algorithms (fueled by swing-curve physics) on how to use these wavelengths are of high importance for a robust recipe setup that can avoid the impact from process stack variations (symmetric as well as asymmetric). All these are discussed. Moreover, another aspect of boosting measurement accuracy and robustness is discussed that deploys the capability to combine overlay measurement data from multiple wavelength measurements. The goal is to provide a method to make overlay measurements immune from process stack variations and also to report health KPIs for every measurement. By combining measurements from multiple wavelengths, a final overlay measurement is generated. The results show a significant benefit in accuracy and robustness against process stack variation. These results are supported by both measurement data as well as simulation from many product stacks.

Shape Optimization for Additive Manufacturing of Removable Partial Dentures--A New Paradigm for Prosthetic CAD/CAM.

Directory of Open Access Journals (Sweden)

Junning Chen

Full Text Available With ever-growing aging population and demand for denture treatments, pressure-induced mucosa lesion and residual ridge resorption remain main sources of clinical complications. Conventional denture design and fabrication are challenged for its labor and experience intensity, urgently necessitating an automatic procedure. This study aims to develop a fully automatic procedure enabling shape optimization and additive manufacturing of removable partial dentures (RPD, to maximize the uniformity of contact pressure distribution on the mucosa, thereby reducing associated clinical complications. A 3D heterogeneous finite element (FE model was constructed from CT scan, and the critical tissue of mucosa was modeled as a hyperelastic material from in vivo clinical data. A contact shape optimization algorithm was developed based on the bi-directional evolutionary structural optimization (BESO technique. Both initial and optimized dentures were prototyped by 3D printing technology and evaluated with in vitro tests. Through the optimization, the peak contact pressure was reduced by 70%, and the uniformity was improved by 63%. In vitro tests verified the effectiveness of this procedure, and the hydrostatic pressure induced in the mucosa is well below clinical pressure-pain thresholds (PPT, potentially lessening risk of residual ridge resorption. This proposed computational optimization and additive fabrication procedure provides a novel method for fast denture design and adjustment at low cost, with quantitative guidelines and computer aided design and manufacturing (CAD/CAM for a specific patient. The integration of digitalized modeling, computational optimization, and free-form fabrication enables more efficient clinical adaptation. The customized optimal denture design is expected to minimize pain/discomfort and potentially reduce long-term residual ridge resorption.

Shape Optimization for Additive Manufacturing of Removable Partial Dentures - A New Paradigm for Prosthetic CAD/CAM

Science.gov (United States)

2015-01-01

With ever-growing aging population and demand for denture treatments, pressure-induced mucosa lesion and residual ridge resorption remain main sources of clinical complications. Conventional denture design and fabrication are challenged for its labor and experience intensity, urgently necessitating an automatic procedure. This study aims to develop a fully automatic procedure enabling shape optimization and additive manufacturing of removable partial dentures (RPD), to maximize the uniformity of contact pressure distribution on the mucosa, thereby reducing associated clinical complications. A 3D heterogeneous finite element (FE) model was constructed from CT scan, and the critical tissue of mucosa was modeled as a hyperelastic material from in vivo clinical data. A contact shape optimization algorithm was developed based on the bi-directional evolutionary structural optimization (BESO) technique. Both initial and optimized dentures were prototyped by 3D printing technology and evaluated with in vitro tests. Through the optimization, the peak contact pressure was reduced by 70%, and the uniformity was improved by 63%. In vitro tests verified the effectiveness of this procedure, and the hydrostatic pressure induced in the mucosa is well below clinical pressure-pain thresholds (PPT), potentially lessening risk of residual ridge resorption. This proposed computational optimization and additive fabrication procedure provides a novel method for fast denture design and adjustment at low cost, with quantitative guidelines and computer aided design and manufacturing (CAD/CAM) for a specific patient. The integration of digitalized modeling, computational optimization, and free-form fabrication enables more efficient clinical adaptation. The customized optimal denture design is expected to minimize pain/discomfort and potentially reduce long-term residual ridge resorption. PMID:26161878

Shape Optimization for Additive Manufacturing of Removable Partial Dentures--A New Paradigm for Prosthetic CAD/CAM.

Science.gov (United States)

Chen, Junning; Ahmad, Rohana; Suenaga, Hanako; Li, Wei; Sasaki, Keiichi; Swain, Michael; Li, Qing

2015-01-01

With ever-growing aging population and demand for denture treatments, pressure-induced mucosa lesion and residual ridge resorption remain main sources of clinical complications. Conventional denture design and fabrication are challenged for its labor and experience intensity, urgently necessitating an automatic procedure. This study aims to develop a fully automatic procedure enabling shape optimization and additive manufacturing of removable partial dentures (RPD), to maximize the uniformity of contact pressure distribution on the mucosa, thereby reducing associated clinical complications. A 3D heterogeneous finite element (FE) model was constructed from CT scan, and the critical tissue of mucosa was modeled as a hyperelastic material from in vivo clinical data. A contact shape optimization algorithm was developed based on the bi-directional evolutionary structural optimization (BESO) technique. Both initial and optimized dentures were prototyped by 3D printing technology and evaluated with in vitro tests. Through the optimization, the peak contact pressure was reduced by 70%, and the uniformity was improved by 63%. In vitro tests verified the effectiveness of this procedure, and the hydrostatic pressure induced in the mucosa is well below clinical pressure-pain thresholds (PPT), potentially lessening risk of residual ridge resorption. This proposed computational optimization and additive fabrication procedure provides a novel method for fast denture design and adjustment at low cost, with quantitative guidelines and computer aided design and manufacturing (CAD/CAM) for a specific patient. The integration of digitalized modeling, computational optimization, and free-form fabrication enables more efficient clinical adaptation. The customized optimal denture design is expected to minimize pain/discomfort and potentially reduce long-term residual ridge resorption.

Long-term efficacy of denture cleansers in preventing Candida spp. biofilm recolonization on liner surface

Directory of Open Access Journals (Sweden)

Ana Paula Coelho Vieira

2010-09-01

Full Text Available This study evaluated the long-term efficacy of denture cleansers against Candida spp. biofilm recolonization on liner surface. Specimens were fabricated of a poly(methyl methacrylate-based denture liner and had their surface roughness evaluated at baseline and after cleansing treatments. C. albicans or C. glabrata biofilms were formed on liner surface for 48 h, and then the specimens were randomly assigned to one of cleaning treatments: two alkaline peroxides (soaking for 3 or 15 min, 0.5% sodium hypochlorite (10 min or distilled water (control; 15 min. After the treatments, the specimens were sonicated to disrupt the biofilm, and residual cells were counted (cell/mL. Long-term effectiveness of the cleaning processes was determined by submitting a set of cleaned specimens to biofilm growth conditions for 48 h followed by estimation of cell counts. The topography of specimens after cleaning treatments was analyzed by SEM. Data were analyzed by ANOVA and Tukey's test (α; = 0.05. Results of cell count estimation showed significant differences in cleanliness among the treatments (p 0.05 was observed among the Candida species regarding the recolonization condition. Alkaline denture cleansers showed similar cleaning performance and both differed from the control (p < 0.001. Sodium hypochlorite was the only treatment that removed biofilm efficiently, since no viable cells were found after its use. In conclusion, alkaline peroxide denture cleansers were not effective in removing Candida spp. biofilm from denture liner surfaces and preventing biofilm recolonization.

Gingival Necrosis Caused by an Ill-Fitting Denture

Directory of Open Access Journals (Sweden)

Vanja VUČIĆEVIĆ BORAS

2014-01-01

Full Text Available We present a case of an 80-year-old male who was referred to the Department of Oral Medicine, School of Dental Medicine University of Zagreb, Croatia due to gingival ulcer which was present for eight days. Clinical examination has revealed exposed bone on the toothless alveolar ridge in the lower molar region on the right side of 0.8 cm in diameter. Otherwise, the patient was taking doxazosin due to urinary problems and ipatropium bromide due to respiratory problems. The patient wore a 6-year-old partial lower denture. He was initially treated with periodontal bandage (Resopack, HagenWerken, Germany for the first three days and was instructed not to wear the denture; however, no benefit could be seen. Therefore, we added a local corticosteroid (betamethasone and an oral antiseptic (chlorhexidine digluconate applied three times a day. After 3 weeks the lesion healed. A list of possible causative factors regarding gingival ulcers is included.

Effect of Gamma Radiation sterilization versus Disinfection on Removable Partial Dentures (Microbiological study)

International Nuclear Information System (INIS)

Mohammed, M.A.

2011-01-01

The aim of the study was to compare between the effectiveness of disinfection, using commercially available Fittydent super cleansing tablets versus sterilization, using gamma radiation on candidal growth in maxillary removable partial dentures. Methods: Fourteen partially edentulous subjects were selected according to specific criteria and divided equally and randomly into two groups; Group I: disinfection group and Group II: sterilization group. Conventional maxillary removable partial dentures were constructed for all subjects. The swab technique was used to collect the samples one month after denture delivery, immediately after disinfection/sterilization, and then one week, two weeks, three weeks, four weeks, and five weeks after disinfection/sterilization respectively. Bacteriological candidal colony count was performed using a manual contact colony counter. Results: Both methods (disinfection and sterilization) led to a noticeable decrease in the candidal count. However this decrease was highly and markedly evident in Group II as compared to Group I. Infact, no candidal growth was recorded for group II immediately after strerilization and was maintained for two more weeks. Statistical analysis revealed highly significant differences between the two groups. Conclusions: Both methods were effective in decreasing the number of Candida albicans adhering to the denture. However, sterilization using Gamma radiation had a more superior immediate, as well as, long term efficiency as compared to disinfection using Fittydent super cleansing tablets.

Impact of removable partial denture prosthesis on chewing efficiency

Science.gov (United States)

BESSADET, Marion; NICOLAS, Emmanuel; SOCHAT, Marine; HENNEQUIN, Martine; VEYRUNE, Jean-Luc

2013-01-01

Removable partial denture prostheses are still being used for anatomic, medical and economic reasons. However, the impact on chewing parameters is poorly described. Objectives The objective of this study was to estimate the impact of removable partial denture prosthesis on masticatory parameters. Material and Methods Nineteen removable partial denture prosthesis (RPDP) wearers participated in the study. Among them, 10 subjects were Kennedy Class III partially edentulous and 9 with posterior edentulism (Class I). All presented a complete and full dentate opposing arch. The subjects chewed samples of carrots and peanuts with and without their prosthesis. The granulometry of the expectorated boluses from carrot and peanuts was characterized by median particle size (D50), determined at the natural point of swallowing. Number of chewing cycles (CC), chewing time (CT) and chewing frequency (CF=CC/CT) were video recorded. Results With RPDP, the mean D50 values for carrot and peanuts were lower [Repeated Model Procedures (RMP), F=15, p<0.001] regardless of the type of Kennedy Class. For each food, mean CC, CT and CF values recorded decreased (RMP, F=18, F=9, and F=20 respectively, p<0.01). With or without RPD, the boluses' granulometry values were above the masticatory normative index (MNI) determined as 4,000 µm. Conclusion RPDP rehabilitation improves the ability to reduce the bolus particle size, but does not reestablish fully the masticatory function. Clinical relevance This study encourages the clinical improvement of oral rehabilitation procedure. PMID:24212983

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

Antifungal Effect of Henna against Candida albicans Adhered to Acrylic Resin as a Possible Method for Prevention of Denture Stomatitis

Science.gov (United States)

Nawasrah, Amal; AlNimr, Amani; Ali, Aiman A.

2016-01-01

Denture stomatitis is a very common disease affecting the oral mucosa of denture wearers. The aim of this study was to measure the antifungal effect of henna against Candida albicans adhered to acrylic resin as a possible method for prevention of denture stomatitis. One-hundred-eighty acrylic plates were prepared of heat-cured acrylic denture resin. The specimens were divided into six groups of 30 samples each. The first group was only polymer and monomer following the conventional manufacturer instruction for processing complete dentures. The other five groups were processed by adding different concentration of Yamani henna powder (Harazi) to the polymer in a concentration of henna: polymer 1%, 2.5%, 5%, 7.5% and 10%, respectively. Samples were incubated in artificial saliva rich with Candida albicans at 37 °C, and the effect of henna on Candida albicans was evaluated in two different methods: semi-quantitative slide count and a culture-based quantitative assay (quantitative). Variation in the number of live Candida was observed with the increase in the concentration of Yamani henna powder. It was observed that the variation in live Candida, between control group and group B (concentration of Yamani henna powder was 1%), was statistically significant with a p-value of 0.0001. Similarly, variations in live Candida were significant, when the concentration of powder was 7.5% or 10% in contrast with control group and p-values were 0.0001 and 0.001 respectively. Adding henna to acrylic resin denture could be effective in controlling Candida albicans proliferation on the denture surface; however, its effects on the physical properties of acrylic resin denture need further studies. PMID:27223294

Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA

Directory of Open Access Journals (Sweden)

Ala Hassan A. Qamheya

2015-01-01

Full Text Available Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC material in teeth construction to rehabilitate a complete denture wearer patient.

A hybrid solution using computational prediction and measured data to accurately determine process corrections with reduced overlay sampling

Science.gov (United States)

Noyes, Ben F.; Mokaberi, Babak; Mandoy, Ram; Pate, Alex; Huijgen, Ralph; McBurney, Mike; Chen, Owen

2017-03-01

Reducing overlay error via an accurate APC feedback system is one of the main challenges in high volume production of the current and future nodes in the semiconductor industry. The overlay feedback system directly affects the number of dies meeting overlay specification and the number of layers requiring dedicated exposure tools through the fabrication flow. Increasing the former number and reducing the latter number is beneficial for the overall efficiency and yield of the fabrication process. An overlay feedback system requires accurate determination of the overlay error, or fingerprint, on exposed wafers in order to determine corrections to be automatically and dynamically applied to the exposure of future wafers. Since current and future nodes require correction per exposure (CPE), the resolution of the overlay fingerprint must be high enough to accommodate CPE in the overlay feedback system, or overlay control module (OCM). Determining a high resolution fingerprint from measured data requires extremely dense overlay sampling that takes a significant amount of measurement time. For static corrections this is acceptable, but in an automated dynamic correction system this method creates extreme bottlenecks for the throughput of said system as new lots have to wait until the previous lot is measured. One solution is using a less dense overlay sampling scheme and employing computationally up-sampled data to a dense fingerprint. That method uses a global fingerprint model over the entire wafer; measured localized overlay errors are therefore not always represented in its up-sampled output. This paper will discuss a hybrid system shown in Fig. 1 that combines a computationally up-sampled fingerprint with the measured data to more accurately capture the actual fingerprint, including local overlay errors. Such a hybrid system is shown to result in reduced modelled residuals while determining the fingerprint, and better on-product overlay performance.

Synthesis of Plaster for moulers's elaboration of imprint denture

International Nuclear Information System (INIS)

Hamiane, M; Rabahi, N; Saidi, M; Salhi, M

2012-01-01

Our goal was the synthesis of plaster from local raw materials to be used in denture mouler's. The plaster type α and β was synthesis by hydrothermal and dry method from gypsum (CaSO4. 2H2O) of the west Algerian. After crushing and mineralogical analysis, gypsum has undergone through cooking in an oven at a temperature (T = 200 ° C), for a time t = 4 hours. The synthesis and characterization of the product has involved several ways investigated as diffraction RX, X-ray fluorescence, time taken, electron microscope (MEB), hardness, SSB, compressive and bending strength and Ph. A digester horizontal type Toni - technical laboratory was used for the synthesis of plasterα. The results are conformable with the standard and plaster synthesized can be a basic material in the manufacture of moulers imprint denture.

Synthesis of Plaster for moulers's elaboration of imprint denture

Science.gov (United States)

Hamiane, M.; Rabahi, N.; Saidi, M.; Salhi, M.

2012-02-01

Our goal was the synthesis of plaster from local raw materials to be used in denture mouler's. The plaster type α and β was synthesis by hydrothermal and dry method from gypsum (CaSO4. 2H2O) of the west Algerian. After crushing and mineralogical analysis, gypsum has undergone through cooking in an oven at a temperature (T = 200 ° C), for a time t = 4 hours. The synthesis and characterization of the product has involved several ways investigated as diffraction RX, X-ray fluorescence, time taken, electron microscope (MEB), hardness, SSB, compressive and bending strength and Ph. A digester horizontal type Toni - technical laboratory was used for the synthesis of plasterα. The results are conformable with the standard and plaster synthesized can be a basic material in the manufacture of moulers imprint denture.

Denture Mis-swallowing in the Sliding Esophageal Hiatal Hernia Mimics Esophageal Perforation

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Chao-Yang Chen

2008-08-01

Full Text Available Mis-swallowing of a foreign body in the esophagus coexisting with sliding hernia might be misdiagnosed as esophageal perforation with mediastinal abscess. We report an 89-year-old woman, bedridden for a long period in a nursing home after a previous cerebrovascular accident, who was sent to our emergency department in a state of sepsis because she had swallowed a radio-opaque partial denture. The retention of the denture as an esophageal foreign body was complicated with mediastinitis and bilateral pleural effusion. The inability of the patient to give a reliable clinical history delayed the diagnosis. This report highlights the difficulty in precisely locating a partial denture because of conflicting radiologic findings and the coexistence of esophageal sliding hernia, all of which led to a misdiagnosis of possible esophageal perforation. A right posterolateral thoracotomy with gastrostomy was performed to remove the lower esophageal foreign body after esophagoscopy failed. The surgical finding of a coincidental sliding esophageal hiatal hernia correlated well with the clinical presentation. Managing such a complicated esophageal foreign body in this elderly patient was challenging.

Gigi tiruan sebagian lepasan sebagai benda asing dalam trakea (Removable partial denture as foreign body in trachea

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Sri Herawati JPB

2005-09-01

Full Text Available Foreign bodies in the trachea are not uncommon. Usually the patients come with dyspnea and a history of having aspirate something. This is an emergency case and needs extraction of the foreign body via bronchoscopy with general anesthesia as soon as possible. The optimal preparation is a controlled, well-equipped and well prepared operative setting. A case of removable partial denture as foreign body in trachea was reported and the extraction of the denture was done with difficulty due to the size of the denture compared with the width of the rima glottis and the trachea.

Recent Advances and Future Perspectives for Reinforcement of Poly(methyl methacrylate Denture Base Materials: A Literature Review

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Sahar Abdulrazzaq Naji

2018-03-01

Full Text Available Poly(methyl methacrylate (PMMA is the most common material used to fabricate complete and partial dentures. Despite its desirable properties, it cannot fulfill all mechanical requirements of prosthesis. Flexural fatigue due to repeated masticatory and high-impact forces caused by dropping are the main causes of denture fractures. In the past, different reinforcing agents such as rubbers, macro fibers, and fillers have been employed to improve the mechanical properties of denture base resins. Development of Nano dentistry has introduced new approaches for reinforcement of dental materials. Interest in nanostructure materials is driven by their high surface area to volume ratio, which enhances interfacial interaction and specific new biological, physical, and chemical properties. Researchers to reinforce PMMA resins have used Nanoparticles (Nps which were comprised of silver, Titania (TiO2, zirconia (ZrO2, alumina, and ceramic. Although different reports describe the use of nanofiber and nanotubes in dental composites, few studies have evaluated the reinforcement potential of nanofiber and nanotubes in PMMA denture base resins. The current article aims to review the different attempts to enhance the mechanical properties of denture base materials. We also focus on recent advances and potential future developments for reinforcement of the PMMA acrylic resins.

Effect of Occlusal Scheme on the Pressure Distribution of Complete Denture Supporting Tissues: An In Vitro Study.

Science.gov (United States)

Madalli, Poornima; Murali, C R; Subhas, Sambit; Garg, Surbhi; Shahi, Prinka; Parasher, Pragati

2015-01-01

The complete denture teeth arrangement that gives maximum denture stability, comfort, esthetics, and function have been studied since several years. Many occlusal schemes have been advised in which the lingualized occlusion, balanced occlusion, and monoplane occlusion are advocated most popularly. The purpose of this study was to compare the pressure values on the supporting tissue using three diff erent posterior occlusal schemes: Balanced occlusion, lingualized occlusion, and monoplane occlusion in simulated dentures. The simulators used in this study, composed of the maxillary, and mandibular clear heat cure acrylic resin edentulous models. Pressures on the supporting structure under the complete denture were measured using eight strain gauges placed on the model surface on the buccal and lingual slopes of the ridges on the molar and pre-molar region. Pressure on the supporting structure was measured and signals from the sensors were amplifi ed and recorded by the multi-channel electronic strain indicator. The mean pressure which was obtained at each measurement point was compared by one-way ANOVA test. Overall monoplane occlusion had lesser pressure values compared to completely balanced and lingualized occlusal scheme. Lingualized occlusal scheme was found to transfer stresses from working side to non-working side to stabilize the mandibular denture.

Approaches of multilayer overlay process control for 28nm FD-SOI derivative applications

Science.gov (United States)

Duclaux, Benjamin; De Caunes, Jean; Perrier, Robin; Gatefait, Maxime; Le Gratiet, Bertrand; Chapon, Jean-Damien; Monget, Cédric

2018-03-01

Derivative technology like embedded Non-Volatile Memories (eNVM) is raising new types of challenges on the "more than Moore" path. By its construction: overlay is critical across multiple layers, by its running mode: usage of high voltage are stressing leakages and breakdown, and finally with its targeted market: Automotive, Industry automation, secure transactions… which are all requesting high device reliability (typically below 1ppm level). As a consequence, overlay specifications are tights, not only between one layer and its reference, but also among the critical layers sharing the same reference. This work describes a broad picture of the key points for multilayer overlay process control in the case of a 28nm FD-SOI technology and its derivative flows. First, the alignment trees of the different flow options have been optimized using a realistic process assumptions calculation for indirect overlay. Then, in the case of a complex alignment tree involving heterogeneous scanner toolset, criticality of tool matching between reference layer and critical layers of the flow has been highlighted. Improving the APC control loops of these multilayer dependencies has been studied with simulations of feed-forward as well as implementing new rework algorithm based on multi-measures. Finally, the management of these measurement steps raises some issues for inline support and using calculations or "virtual overlay" could help to gain some tool capability. A first step towards multilayer overlay process control has been taken.

Precise X-ray and video overlay for augmented reality fluoroscopy.

Science.gov (United States)

Chen, Xin; Wang, Lejing; Fallavollita, Pascal; Navab, Nassir

2013-01-01

The camera-augmented mobile C-arm (CamC) augments any mobile C-arm by a video camera and mirror construction and provides a co-registration of X-ray with video images. The accurate overlay between these images is crucial to high-quality surgical outcomes. In this work, we propose a practical solution that improves the overlay accuracy for any C-arm orientation by: (i) improving the existing CamC calibration, (ii) removing distortion effects, and (iii) accounting for the mechanical sagging of the C-arm gantry due to gravity. A planar phantom is constructed and placed at different distances to the image intensifier in order to obtain the optimal homography that co-registers X-ray and video with a minimum error. To alleviate distortion, both X-ray calibration based on equidistant grid model and Zhang's camera calibration method are implemented for distortion correction. Lastly, the virtual detector plane (VDP) method is adapted and integrated to reduce errors due to the mechanical sagging of the C-arm gantry. The overlay errors are 0.38±0.06 mm when not correcting for distortion, 0.27±0.06 mm when applying Zhang's camera calibration, and 0.27±0.05 mm when applying X-ray calibration. Lastly, when taking into account all angular and orbital rotations of the C-arm, as well as correcting for distortion, the overlay errors are 0.53±0.24 mm using VDP and 1.67±1.25 mm excluding VDP. The augmented reality fluoroscope achieves an accurate video and X-ray overlay when applying the optimal homography calculated from distortion correction using X-ray calibration together with the VDP.

The effect of cleaning substances on the surface of denture base material.

Science.gov (United States)

Žilinskas, Juozas; Junevičius, Jonas; Česaitis, Kęstutis; Junevičiūtė, Gabrielė

2013-12-11

The aim of this study was to evaluate the effect of substances used for hygienic cleaning of dentures on the surface of the denture base material. Meliodent Heat Cure (Heraeus-Kulzer, Germany) heat-polymerized acrylic resin was used to produce plates with all the characteristics of removable denture bases (subsequently, "plates"). Oral-B Complete toothbrushes of various brush head types were fixed to a device that imitated tooth brushing movements; table salt and baking soda (frequently used by patients to improve tooth brushing results), toothpaste ("Colgate Total"), and water were also applied. Changes in plate surfaces were monitored by measuring surface reflection alterations on spectrometry. Measurements were conducted before the cleaning and at 2 and 6 hours after cleaning. No statistically significant differences were found between the 3 test series. All 3 plates used in the study underwent statistically significant (pbaking soda--the total reflection reduction was 4.82 ± 0.1%; among toothbrushes with toothpaste, the hard-type toothbrush had the greatest reflection-reducing effect--4.6 ± 0.05%, while the toothbrush with table salt inflicted the least damage (3.5 ± 0.16%) due to the presence of rounded crystals between the bristles and the resin surface. Toothbrushes with water had a uniform negative effect on the plate surface - 3.8 9 ± 0.07%. All substances used by the patients caused surface abrasion of the denture base material, which reduced the reflection; a hard toothbrush with toothpaste had the greatest abrasive effect, while soft toothbrushes inflicted the least damage.

Two Dimensional Array Based Overlay Network for Balancing Load of Peer-to-Peer Live Video Streaming

International Nuclear Information System (INIS)

Ibrahimy, Abdullah Faruq Ibn; Rafiqul, Islam Md; Anwar, Farhat; Ibrahimy, Muhammad Ibn

2013-01-01

The live video data is streaming usually in a tree-based overlay network or in a mesh-based overlay network. In case of departure of a peer with additional upload bandwidth, the overlay network becomes very vulnerable to churn. In this paper, a two dimensional array-based overlay network is proposed for streaming the live video stream data. As there is always a peer or a live video streaming server to upload the live video stream data, so the overlay network is very stable and very robust to churn. Peers are placed according to their upload and download bandwidth, which enhances the balance of load and performance. The overlay network utilizes the additional upload bandwidth of peers to minimize chunk delivery delay and to maximize balance of load. The procedure, which is used for distributing the additional upload bandwidth of the peers, distributes the additional upload bandwidth to the heterogeneous strength peers in a fair treat distribution approach and to the homogeneous strength peers in a uniform distribution approach. The proposed overlay network has been simulated by Qualnet from Scalable Network Technologies and results are presented in this paper

Two Dimensional Array Based Overlay Network for Balancing Load of Peer-to-Peer Live Video Streaming

Science.gov (United States)

Faruq Ibn Ibrahimy, Abdullah; Rafiqul, Islam Md; Anwar, Farhat; Ibn Ibrahimy, Muhammad

2013-12-01

The live video data is streaming usually in a tree-based overlay network or in a mesh-based overlay network. In case of departure of a peer with additional upload bandwidth, the overlay network becomes very vulnerable to churn. In this paper, a two dimensional array-based overlay network is proposed for streaming the live video stream data. As there is always a peer or a live video streaming server to upload the live video stream data, so the overlay network is very stable and very robust to churn. Peers are placed according to their upload and download bandwidth, which enhances the balance of load and performance. The overlay network utilizes the additional upload bandwidth of peers to minimize chunk delivery delay and to maximize balance of load. The procedure, which is used for distributing the additional upload bandwidth of the peers, distributes the additional upload bandwidth to the heterogeneous strength peers in a fair treat distribution approach and to the homogeneous strength peers in a uniform distribution approach. The proposed overlay network has been simulated by Qualnet from Scalable Network Technologies and results are presented in this paper.

Assessment of the impact strength of the denture base resin polymerized by various processing techniques

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Rajashree Jadhav

2013-01-01

Full Text Available Aim : To measure the impact strength of denture base resins polymerized using short and long curing cycles by water bath, pressure cooker and microwave techniques. Materials and Methods: For impact strength testing, 60 samples were made. The sample dimensions were 60 mm × 12 mm × 3 mm, as standardized by the American Standards for Testing and Materials (ASTM. A digital caliper was used to locate the midpoint of sample. The impact strength was measured in IZOD type of impact tester using CEAST Impact tester. The pendulum struck the sample and it broke. The energy required to break the sample was measured in Joules. Data were analyzed using Student′s " t" test. Results: There was statistically significant difference in the impact strength of denture base resins polymerized by long curing cycle and short curing cycle in each technique, with the long curing processing being the best. Conclusion: The polymerization technique plays an important role in the influence of impact strength in the denture base resin. This research demonstrates that the denture base resin polymerized by microwave processing technique possessed the highest impact strength.

Overlay field application program, Pennsylvania US-119.

Science.gov (United States)

2010-11-01

The Concrete Overly Filed Application program is administered by FHWA and the National Concrete Pavement Technology Center (CP Tech Center). The overall objective of this program is to increase the awareness and knowledge of concrete overlay applicat...

Implementation and benefits of advanced process control for lithography CD and overlay

Science.gov (United States)

Zavyalova, Lena; Fu, Chong-Cheng; Seligman, Gary S.; Tapp, Perry A.; Pol, Victor

2003-05-01

Due to the rapidly reduced imaging process windows and increasingly stingent device overlay requirements, sub-130 nm lithography processes are more severely impacted than ever by systamic fault. Limits on critical dimensions (CD) and overlay capability further challenge the operational effectiveness of a mix-and-match environment using multiple lithography tools, as such mode additionally consumes the available error budgets. Therefore, a focus on advanced process control (APC) methodologies is key to gaining control in the lithographic modules for critical device levels, which in turn translates to accelerated yield learning, achieving time-to-market lead, and ultimately a higher return on investment. This paper describes the implementation and unique challenges of a closed-loop CD and overlay control solution in high voume manufacturing of leading edge devices. A particular emphasis has been placed on developing a flexible APC application capable of managing a wide range of control aspects such as process and tool drifts, single and multiple lot excursions, referential overlay control, 'special lot' handling, advanced model hierarchy, and automatic model seeding. Specific integration cases, including the multiple-reticle complementary phase shift lithography process, are discussed. A continuous improvement in the overlay and CD Cpk performance as well as the rework rate has been observed through the implementation of this system, and the results are studied.

Reduction of image-based ADI-to-AEI overlay inconsistency with improved algorithm

Science.gov (United States)

Chen, Yen-Liang; Lin, Shu-Hong; Chen, Kai-Hsiung; Ke, Chih-Ming; Gau, Tsai-Sheng

2013-04-01

In image-based overlay (IBO) measurement, the measurement quality of various measurement spectra can be judged by quality indicators and also the ADI-to-AEI similarity to determine the optimum light spectrum. However we found some IBO measured results showing erroneous indication of wafer expansion from the difference between the ADI and the AEI maps, even after their measurement spectra were optimized. To reduce this inconsistency, an improved image calculation algorithm is proposed in this paper. Different gray levels composed of inner- and outer-box contours are extracted to calculate their ADI overlay errors. The symmetry of intensity distribution at the thresholds dictated by a range of gray levels is used to determine the particular gray level that can minimize the ADI-to-AEI overlay inconsistency. After this improvement, the ADI is more similar to AEI with less expansion difference. The same wafer was also checked by the diffraction-based overlay (DBO) tool to verify that there is no physical wafer expansion. When there is actual wafer expansion induced by large internal stress, both the IBO and the DBO measurements indicate similar expansion results. The scanning white-light interference microscope was used to check the variation of wafer warpage during the ADI and AEI stages. It predicts a similar trend with the overlay difference map, confirming the internal stress.

VT Data - Cons/Rec Overlay District 20110301, Winhall

Data.gov (United States)

Vermont Center for Geographic Information — Conservation and Recreatioal Protection overaly districts for the Town of Winhall, Vermont. Other overlay districts (Transfer of Development Rights, and Scenic...

Effects of trimethylsilane plasma coating on the hydrophobicity of denture base resin and adhesion of Candida albicans on resin surfaces.

Science.gov (United States)

Liu, Tianshuang; Xu, Changqi; Hong, Liang; Garcia-Godoy, Franklin; Hottel, Timothy; Babu, Jegdish; Yu, Qingsong

2017-12-01

Candida-associated denture stomatitis is the most common oral mucosal lesion among denture wearers. Trimethylsilane (TMS) plasma coating may inhibit the growth of Candida albicans on denture surfaces. The purpose of this in vitro study was to investigate whether TMS plasma coatings can effectively reduce C albicans adhesion on denture base acrylic resin surfaces. Sixty denture base acrylic resin disks with smooth and rough surfaces were prepared and were either left untreated (control group) or coated with TMS monomer (experimental group) by using plasma. Contact angles were measured immediately after TMS plasma coating. The morphology of C albicans adhesion was observed with scanning electron microscopy (SEM). Energy-dispersive spectroscopy (EDS) was used to characterize the elemental composition of the specimen surface. An adhesion test was performed by incubating the resin disk specimens in C albicans suspensions (1×10 7 cells/mL) at 37°C for 24 hours and further measuring the optical density of the C albicans by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay test. One-way ANOVA and 2-way ANOVA were followed by a post hoc test analysis (α=.05). The group with TMS coating exhibited a more hydrophobic surface than the control group. EDS analysis revealed successful TMS plasma coating. The difference in the mean contact angles between the uncoated group and the TMS-coated group was statistically significant (Pcoating than on the surfaces of the experimental group. In the adhesion test, the amount of C albicans adhering to the surface of denture base resin with the TMS coating was significantly less than that on the surfaces without TMS coating (Pcoating significantly reduced the adhesion of C albicans to the denture base resin and may reduce denture stomatitis. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

The removable acrylic partial denture in primary care: the experience and satisfaction of dental surgeons

Directory of Open Access Journals (Sweden)

Rita de Cássia SILVA

2017-11-01

Full Text Available Abstract Introduction The guidelines of the National Politics of Oral Health have led to the inclusion of elemental prostheses in the list of Primary Care procedures. Objective This paper aimed to evaluate the performance and satisfaction of dental surgeons with the implementation of Acrylic Partial Dentures. Metodology The sample was composed by 159 dental surgeons (sample calculation, in Belo Horizonte, MG, Brazil, selected via raffle (simple random sampling. A structured questionnaire was built with 72 questions on the daily practice of the performance of dental surgeons, using the SurveyMonkey platform. Result The results showed that for most of dental surgeons, the inclusion on the list of primary care procedures was a positive initiative and they have enjoyed the experience of using Acrylic Partial Dentures. Dental surgeons who had graduated in private institutions reported to have had more failures than those who had graduated in public institutions. The better prepared dental surgeons reported less difficulties and failures, and the more satisfied professionals with the performance of Acrylic Partial Dentures related had also experienced fewer failures. Considering the indication, the majority of participants did it according to the protocol of the institution (only for anterior teeth but many revealed the use of dentures also for premolars. Conclusion Acrylic partial dentures have been a reality in the Brazilian social context even before their inclusion in the list of Primary Care procedures. Such inclusion indicates their relevance; however, it is necessary to have their confection systematized by a protocol in public services.

Should edentulous patients be constrained to removable complete dentures? The use of dental implants to improve the quality of life for edentulous patients.

Science.gov (United States)

Turkyilmaz, Ilser; Company, Andrea M; McGlumphy, Edwin A

2010-03-01

Nowadays, there is some speculation among dental educators that the need for complete dentures will significantly decrease in the future and that training in their provision should be removed from the dental curriculum. To sensitise the reader to the functional shortcomings of complete denture therapy in the edentulous patient and present restorative options including implants to improve edentulous quality of life in these patients. Information retrieval followed a systematic approach using PubMed. English articles published from 1964 to 2008, in which the masticatory performance of patients with implant-supported dentures was assessed by objective methods and compared with performance with conventional dentures, were included. National epidemiological survey data suggested that the adult population in need of one or two complete dentures will increase from 35.4 million adults in 2000 to 37.9 million adults in 2020. Clinical studies have showed that the ratings of general satisfaction were significantly better in the patients treated with implant overdentures post-delivery compared with the complete denture users. In addition, the implant group gave significantly higher ratings on comfort, stability and ability to chew. Furthermore, patients who received mandibular implant overdentures had significantly fewer oral health-related quality of life problems than did the conventional group. Implant-supported dentures including either complete overdentures or a hybrid prosthesis significantly improve the quality of life for edentulous patients compared with conventional removable complete dentures. Therefore, the contemporary dental practitioner should consider other options as well as conventional removable complete dentures to restore edentulous patients.

Effects of concrete moisture on polymer overlay bond over new concrete : [technical summary].

Science.gov (United States)

2015-06-01

Epoxy polymer overlays have been used for decades on existing bridge decks to protect : the deck and extend its service life. The polymer overlays ability to seal a bridge deck : is now being specified for new construction. Questions exist about t...

Bandwidth and power allocation for two-way relaying in overlay cognitive radio systems

KAUST Repository

Alsharoa, Ahmad M.; Ghazzai, Hakim; Yaacoub, Elias E.; Alouini, Mohamed-Slim

2014-01-01

In this paper, the problem of both bandwidth and power allocation for two-way multiple relay systems in overlay cognitive radio (CR) setup is investigated. In the CR overlay mode, primary users (PUs) cooperate with cognitive users (CUs) for mutual

Performance of thin bonded epoxy overlays on asphalt and concrete bridge deck surfaces.

Science.gov (United States)

2014-06-01

This study is the evaluation of two thin bonded epoxy overlays: SafeLane (marketed by Cargill), and Flexogrid : (developed by PolyCarb). SafeLane is advertised as an anti-skid/anti-icing overlay that stores deicing chemicals for : release during wint...

[Microbiological testing of the artificial gingival margin in dentures].

Science.gov (United States)

Hermann, Péter; Klein, Ildikó; Barna, Zsuzsanna; Kaán, Miklós; Fejérdy, Pál

2004-06-01

In everyday practice dental laboratories try to reproduce the natural form of sulcus gingivae at the transitional area between artificial teeth and gingiva of removable dentures, even on esthetically less important areas. Aim of these investigations were to examine how artificial recreation of the sulcus gingivae influences plaque retention, and what is the microbiological relevance of these. Investigations were carried out on the vestibular side of removable dentures of 32 randomly selected patients treated at the Department of Prosthodontics at the Faculty of Dentistry, Semmelweis University. Microbiological samples were taken from each patient using the same method. Samples were taken from the left upper first molars' artificial gingival margin using sterile paper points. Paper points were then transported in Eppendorf-tubes, in 2 ml of physiological saline solution, and processed within a two-hour period of time. Series dilutions were made of the sample solutions, then surface-streaked on Subaraud and Gentamycin, blood-agar, eosin-methylene blue and Mitis Salivarius culture enriched with Bacitracin. Subaraud culture was induced under aerob conditions, at room temperature for two days, then the total amount of fungi quantified. After pure-culturing Candida albicans ID-culture was used for identification, and BioMerieux ATB automatic equipment to identify different Candida species. From pure cultures identification was carried out with Gram-staining, Neisser-staining, catalase, oxidase and also with other biochemical reactions. Blood-agar was used to determine total germ count, and normal commensal pharyngeal and oral bacteria. After collecting the microbiological samples, the conventional shape of the dental margin of gingiva was abolished on one side of the dentures and a smooth transition was created between denture teeth and the artificial gingiva in the molar and premolar region. During our investigations only blastomycetes were found. Besides most common

Combination of Bayesian Network and Overlay Model in User Modeling

Directory of Open Access Journals (Sweden)

Loc Nguyen

2009-12-01

Full Text Available The core of adaptive system is user model containing personal information such as knowledge, learning styles, goals… which is requisite for learning personalized process. There are many modeling approaches, for example: stereotype, overlay, plan recognition… but they don’t bring out the solid method for reasoning from user model. This paper introduces the statistical method that combines Bayesian network and overlay modeling so that it is able to infer user’s knowledge from evidences collected during user’s learning process.

Oral Crest Lengthening for Increasing Removable Denture Retention by Means of CO2 Laser

Directory of Open Access Journals (Sweden)

Samir Nammour

2014-01-01

Full Text Available The loss of teeth and their replacement by artificial denture is associated with many problems. The denture needs a certain amount of ridge height to give it retention and a long-term function. Crest lengthening procedures are performed to provide a better anatomic environment and to create proper supporting structures for more stability and retention of the denture. The purpose of our study is to describe and evaluate the effectiveness of CO2 laser-assisted surgery in patients treated for crest lengthening (vestibular deepening. There have been various surgical techniques described in order to restore alveolar ridge height by pushing muscles attaching of the jaws. Most of these techniques cause postoperative complications such as edemas, hemorrhage, pain, infection, slow healing, and rebound to initial position. Our clinical study describes the treatment planning and clinical steps for the crest lengthening with the use of CO2 laser beam (6–15 Watts in noncontact, energy density range: 84.92–212.31 J/cm2, focus, and continuous mode with a focal point diameter of 0.3 mm. At the end of each surgery, dentures were temporarily relined with a soft material. Patients were asked to mandatorily wear their relined denture for a minimum of 4–6 weeks and to remove it for hygienic purposes. At the end of each surgery, the deepest length of the vestibule was measured by the operator. No sutures were made and bloodless wounds healed in second intention without grafts. Results pointed out the efficiency of the procedure using CO2 laser. At 8 weeks of post-op, the mean of crest lengthening was stable without rebound. Only a loss of 15% was noticed. To conclude, the use of CO2 laser is an effective option for crest lengthening.

Cell cycle indicators of buccal epithelial cells in the treatment of different types of removable plate partial dentures

Directory of Open Access Journals (Sweden)

E. V. Beliaiev

2018-02-01

Full Text Available The purpose of the work. To investigate nuclear DNA and buccal epithelial cells proliferative activity in patients with dental defects, who use removable partial dentures plates made of acrylic or thermoplastic. Materials and Methods. The study of buccal epithelial cell cycle parameters was carried out in 70 people. Among them 23 patients were treated with acrylic dentures prostheses, 23 patients – with thermoplastic-based prostheses. The comparison group consisted of 24 clinically healthy persons without defects in the dentition. DNA content in human buccal epithelial cells nuclei was determined by flow cytometry. Results. The obtained indicators of buccal epithelial cell cycle of the control group indicate a high intensity of cell self-renewal in the normal range. It is suggested by a significant percentage of events occurring within the Sub-G1 range that characterizes apoptosis, as well as the fact that more than half of the cells were in the range of S + G2/M. It has been revealed by flow cytometry that the percentage of apoptosis in cells was higher in patients using acrylic dentures base plastic, showed initial signs of keratinization that was confirmed by increase in cells in the range of Sub-G1 and by their decrease in the range of S-G2/M. It has been established in the study of buccal epithelium cell cycle indicators in the dentures bases thermoplastic application that these prostheses did not affect the proliferative activity of buccal epithelial cells compared to the group using acrylic dentures bases with prolonged use. This is evident in almost the same number of cellular events ranging Sub-G1, so apoptosis in the thermoplastic dentures bases application corresponded to the control group indicators both in the early period and over a year of use. Conclusions. The direct negative effect of prostheses with acrylic bases on the complex mechanism of the oral cavity mucous membrane functioning has been revealed. Absence of dentures

Overlay Spectrum Sharing using Improper Gaussian Signaling

KAUST Repository

Amin, Osama; Abediseid, Walid; Alouini, Mohamed-Slim

2016-01-01

in overlay cognitive radio system, where the secondary transmitter broadcasts a mixture of two different signals. The first signal is selected from the PGS scheme to match the primary message transmission. On the other hand, the second signal is chosen

"Nature cures:" An alternative herbal formulation as a denture cleanser.

Science.gov (United States)

Sushma, R; Sathe, Tanuja Tanaji; Farias, Anand; Sanyal, Pronob Kumar; Kiran, Shashi

2017-01-01

Candida albicans is one of the microorganisms which harbor the oral cavity, especially in elderly. However, the incidence of existence of this increases in patients using removable dental prosthesis. There is therefore a need to test the anticandidal efficacy of these cost-effective, easily available products to be used as routine denture cleansers. (1) To evaluate antifungal properties of triphala churna on the heat cure denture base material. (2) To evaluate the antifungal effect of chlorhexidine gluconate on the heat cure denture base material. (3) To compare the antifungal effect of triphala churna and chlorhexidine gluconate with a control. (4) To evaluate which among triphala churna and chlorhexidine gluconate has a better antifungal property on the heat cure denture base material. Study population consisted of sixty dentures wearers from those attending the Outpatient Department of Prosthodontics of the School of Dentistry, Krishna Institute of Medical Sciences Deemed University, Karad. Swabs were collected from the dentures before and after the use of triphala and chlorhexidine. The swabs were cultured on Sabouraud dextrose agar and the total Candida counts were determined. Triphala as an antifungal is shown to have more efficacy than the conventional chlorhexidine mouthwash. Résumé Arrière-plan: Candida albicans est l'un des micro-organismes qui abritent la cavité buccale surtout chez les personnes âgées. Cependant, l'incidence de l'existence de cette augmentation chez les patients utilisant des prothèses dentaires amovibles. Il est donc nécessaire de tester l'efficacité anticancédique de ces produits rentables et faciles à utiliser pour être utilisés comme nettoyants de routine pour prothèses dentaires. Buts et Objectifs: (1) Évaluer les propriétés antifongiques de Triphala churna sur le matériau de base de la prothèse thermo-durcissable. (2) Évaluer l'effet antifongique du gluconate de chlorhexidine sur le matériau de base de la

Evaluating stress distribution in two different designs of class I partial removable dentures

Directory of Open Access Journals (Sweden)

F. Geramipanah

1998-05-01

Full Text Available In Present study a digital model of hemimaxillectomy was reconstructed by computer and stress distribution of removable partial dentures in tissues, periodontal ligament and bone were thoroughly evaluated. The maximum stress of two different removable partial denture designs which contained buccal and lingual c-shaped clasps respectively were analyzed and compared. It was assumed that a 90 gram force which is equal to an average obturator’s weight is applied outwardly. The results showed that the maximum stress distribution in these two designs is not significantly different.

Cost-effectiveness of implant-supported mandibular removable partial dentures

NARCIS (Netherlands)

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

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

Photoelastic analysis of mandibular full-arch implant-supported fixed dentures made with different bar materials and manufacturing techniques.

Science.gov (United States)

Zaparolli, Danilo; Peixoto, Raniel Fernandes; Pupim, Denise; Macedo, Ana Paula; Toniollo, Marcelo Bighetti; Mattos, Maria da Glória Chiarello de

2017-12-01

To compare the stress distribution of mandibular full dentures supported with implants according to the bar materials and manufacturing techniques using a qualitative photoelastic analysis. An acrylic master model simulating the mandibular arch was fabricated with four Morse taper implant analogs of 4.5×6mm. Four different bars were manufactured according to different material and techniques: fiber-reinforced resin (G1, Trinia, CAD/CAM), commercially pure titanium (G2, cpTi, CAD/CAM), cobalt‑chromium (G3, Co-Cr, CAD/CAM) and cobalt‑chromium (G4, Co-Cr, conventional cast). Standard clinical and laboratory procedures were used by an experienced dental technician to fabricate 4 mandibular implant-supported dentures. The photoelastic model was created based on the acrylic master model. A load simulation (150N) was performed in total occlusion against the antagonist. Dentures with fiber-reinforced resin bar (G1) exhibited better stress distribution. Dentures with machined Co-Cr bar (G3) exhibited the worst standard of stress distribution, with an overload on the distal part of the posteriors implants, followed by dentures with cast Co-Cr bar (G4) and machined cpTi bar (G2). The fiber-reinforced resin bar exhibited an adequate stress distribution and can serve as a viable alternative for oral rehabilitation with mandibular full dentures supported with implants. Moreover, the use of the G1 group offered advantages including reduced weight and less possible overload to the implants components, leading to the preservation of the support structure. Copyright © 2017 Elsevier B.V. All rights reserved.

A Randomized Controlled Trial of Mastication with Complete Dentures Made by a Conventional or an Abbreviated Technique.

Science.gov (United States)

Mengatto, Cristiane Machado; Gameiro, Gustavo Hauber; Brondani, Mario; Owen, C Peter; MacEntee, Michael I

The aim of this randomized clinical trial was to test the hypothesis that there are no statistically significant differences after 3 and 6 months in masticatory performance or chewing ability of people with new complete dentures made by an abbreviated or a conventional technique. The trial included 20 edentulous participants at a dental school in Brazil assigned randomly to receive dentures made by either a conventional technique involving six clinical sessions or by an abbreviated technique involving three clinical sessions. At baseline with old dentures and at 3 and 6 months with new dentures, masticatory performance was measured by counting the number of chewing strokes and the time before participants had an urge to swallow and by calculating the medium particle size of a silicone material after 20 chewing strokes and at the urge to swallow. On each occasion, the participants recorded on visual analog scales their ability to chew five food textures. Statistical significance (P ≤ .05) of changes in masticatory performance and chewing ability during the trial were analyzed with generalized estimating equations. Both techniques improved masticatory performance between baseline and 6 months and the ability to bite and chew all foods apart from hard apples. There were no significant differences in masticatory performance or chewing ability after 6 months between complete dentures made by a conventional or an abbreviated technique.

Pattern of Demand for Removable Acrylic Partial Denture (RPD) in ...

African Journals Online (AJOL)

Alasia Datonye

prosthodontic need in the future. Furthermore, an overall ... As socio-economic depression continues to cut across the world particularly .... preserved. Data Management ... for lower partial denture in our study but Idowu and AI-. 12. Shamrani ...

Welding overlay analysis of dissimilar metal weld cracking of feedwater nozzle

International Nuclear Information System (INIS)

Tsai, Y.L.; Wang, Li. H.; Fan, T.W.; Ranganath, Sam; Wang, C.K.; Chou, C.P.

2010-01-01

Inspection of the weld between the feedwater nozzle and the safe end at one Taiwan BWR showed axial indications in the Alloy 182 weld. The indication was sufficiently deep that continued operation could not be justified considering the crack growth for one cycle. A weld overlay was decided to implement for restoring the structural margin. This study reviews the cracking cases of feedwater nozzle welds in other nuclear plants, and reports the lesson learned in the engineering project of this weld overlay repair. The overlay design, the FCG calculation and the stress analysis by FEM are presented to confirm that the Code Case structural margins are met. The evaluations of the effect of weld shrinkage on the attached feedwater piping are also included. A number of challenges encountered in the engineering and analysis period are proposed for future study.

[Foreign dentures and dental tourism--willingness-to-pay and factors influencing the demand for foreign dental prosthesis in Germany].

Science.gov (United States)

Köberlein, J; Klingenberger, D

2011-07-01

With the progressive realisation of the single European market, public interest has been directed towards cross-border healthcare services to an increasing extent. More and more dentures are being imported into Germany from foreign countries. Furthermore, patients are becoming ever more mobile, travelling to other countries to receive prosthetic treatment from dentists. The objective of this evaluation was to determine by means of a dedicated questionnaire the patients' individual preferences for foreign dentures and the potential savings. 1 368 individuals between the ages of 30 and 75 years were interviewed within a representative omnibus survey. The evaluation of the individual willingness-to-pay included 4 treatment scenarios, which were assessed by the participants in a "bidding game". Participants could choose between a "crown scenario" and an "implant scenario", both with the subcategories "foreign dentures" and "dental tourism". The direct comparison revealed a preference for the "foreign dentures" option over "dental tourism". Average willingness-to-pay for the dental tourism option in the crown scenario was calculated as 80 Euro, and in the implant scenario as 280 Euro less in comparison with the willingness-to-pay for the foreign dentures option. The willingness to switch to a less expensive dentist was one of the main determinants in the causal explanation for the variance in willingness-to-pay. Quality proved to be the decisive criterion and was indicated by 92.4% participants. A lower price for dentures played a subordinate role and was only stated as the decisive factor by 31.1% participants. In conclusion, the results clearly indicate that the decision for or against foreign dentures and the extent of willingness-to-pay depends on a range of criteria, of which "price" is only one and not the decisive factor. © Georg Thieme Verlag KG Stuttgart · New York.

Residual stress measurement in 304 stainless steel weld overlay pipes

International Nuclear Information System (INIS)

Yen, H.J.; Lin, M.C.C.; Chen, L.J.

1996-01-01

Welding overlay repair (WOR) is commonly employed to rebuild piping systems suffering from intergranular stress corrosion cracking (IGSCC). To understand the effects of this repair, it is necessary to investigate the distribution of residual stresses in the welding pipe. The overlay welding technique must induce compressive residual stress at the inner surface of the welded pipe to prevent IGSCC. To understand the bulk residual stress distribution, the stress profile as a function of location within wall is examined. In this study the full destructive residual stress measurement technique -- a cutting and sectioning method -- is used to determine the residual stress distribution. The sample is type 304 stainless steel weld overlay pipe with an outside diameter of 267 mm. A pipe segment is cut from the circular pipe; then a thin layer is removed axially from the inner to the outer surfaces until further sectioning is impractical. The total residual stress is calculated by adding the stress relieved by cutting the section away to the stress relieved by axially sectioning. The axial and hoop residual stresses are compressive at the inner surface of the weld overlay pipe. Compressive stress exists not only at the surface but is also distributed over most of the pipe's cross section. On the one hand, the maximum compressive hoop residual stress appears at the pipe's inner surface. The thermal-mechanical induced crack closure from significant compressive residual stress is discussed. This crack closure can thus prevent IGSCC very effectively

Esthetic double-structure fixed partial dentures.

Science.gov (United States)

Ravasini, G; Ugolini, G; Ravasini, F

1996-04-01

A new technical procedure for fixed partial dentures and single inlays allows the use of a metal supporting structure with independent ceramic coverage. The advantages of the technique are the bonding of metal to beveled dentinal margins with conventional cement and the acid-etched resin composite cementation of the ceramic, which permits more conservative preparation of the teeth. The complexity of the structure, the laboratory costs, and the doubling of the cementation procedures are the main disadvantages of the technique.

Sectional removable partial denture design for the treatment of ...

African Journals Online (AJOL)

Sectional removable partial denture design for the treatment of partial mandibulectomy patient: a case report. ... mandibulectomy with no surgical reconstruction. The case was challenging and the prosthesis was well tolerated during a 6 months follow-up review. (Afr. J. Biomed. Res. 10: 197 - 201). Keywords: Removable ...

Flipped clinical training: a structured training method for undergraduates in complete denture prosthesis.

Science.gov (United States)

K, Anbarasi; K, Kasim Mohamed; Vijayaraghavan, Phagalvarthy; Kandaswamy, Deivanayagam

2016-12-01

To design and implement flipped clinical training for undergraduate dental students in removable complete denture treatment and predict its effectiveness by comparing the assessment results of students trained by flipped and traditional methods. Flipped training was designed by shifting the learning from clinics to learning center (phase I) and by preserving the practice in clinics (phase II). In phase I, student-faculty interactive session was arranged to recap prior knowledge. This is followed by a display of audio synchronized video demonstration of the procedure in a repeatable way and subsequent display of possible errors that may occur in treatment with guidelines to overcome such errors. In phase II, live demonstration of the procedure was given. Students were asked to treat three patients under instructor's supervision. The summative assessment was conducted by applying the same checklist criterion and rubric scoring used for the traditional method. Assessment results of three batches of students trained by flipped method (study group) and three traditionally trained previous batches (control group) were taken for comparison by chi-square test. The sum of traditionally trained three batch students who prepared acceptable dentures (score: 2 and 3) and unacceptable dentures (score: 1) was compared with the same of flipped trained three batch students revealed that the number of students who demonstrated competency by preparing acceptable dentures was higher for flipped training (χ 2 =30.996 with p<0.001). The results reveal the supremacy of flipped training in enhancing students competency and hence recommended for training various clinical procedures.

Opportunistic transmitter selection for selfless overlay cognitive radios

KAUST Repository

Shaqfeh, Mohammad; Zafar, Ammar; Alnuweiri, Hussein M.; Alouini, Mohamed-Slim

2013-01-01

We propose an opportunistic strategy to grant channel access to the primary and secondary transmitters in causal selfless overlay cognitive radios over block-fading channels. The secondary transmitter helps the primary transmitter by relaying

Epidemiological Data and Survival Rate of Removable Partial Dentures

Science.gov (United States)

Moreno, Amália; Haddad, Marcela Filié; Rocha, Eduardo Passos; Assunção, Wirley Gonçalves; Filho, Humberto Gennari; Santos, Emerson Gomes Dos; Sonego, Mariana Vilela; Santos, Daniela Micheline Dos

2016-01-01

Introduction The use of removable partial denture (RPD) is considered as low-cost and common treatment option to rehabilitate edentulous areas. Aim This study aimed to investigate the epidemiological data of patients rehabilitated with removable partial denture (RPD) in order to assess treatment survival rate and failures. Materials and Methods Epidemiological data and medical records of patients treated with RPD between 2007 and 2012 at the RPD discipline of a Brazilian University (Aracatuba Dental School- UNESP) were evaluated as well as dental records of patients who underwent RPD treatments (fabrication or repairs) between 2000 and 2010. Factors such as gender, age, presence of systemic disease, main complaint, edentulous arch, period and cause of denture replacement and the prosthesis characteristics were recorded. The chi-square test was used to assess the differences between the variables and the Kaplan Meyer to assess the survival of the RPDs evaluated. Results A total of 324 maxillary RPD and 432 mandibular RPD were fabricated. Most of the patients were women aging 41 to 60-year-old. The number of mandibular RPD Kennedy class I (26%) was statistically higher for the maxillary arch (p<.05). There was no association between main complaint to gender or the presence of systemic disease. The lingual plate was the most common major connector used in the mandible (32%). The main reason for altering the design of replaced RPDs were changes during treatment plan. Conclusion The number of patients who require RPD is large; most of RPDs are Kennedy Class I. A good treatment plan is very important for achieving a positive treatment outcome, and it is strictly related to the survival rate. PMID:27437367

Advancements of diffraction-based overlay metrology for double patterning

Science.gov (United States)

Li, Jie; Kritsun, Oleg; Liu, Yongdong; Dasari, Prasad; Weher, Ulrich; Volkman, Catherine; Mazur, Martin; Hu, Jiangtao

2011-03-01

As the dimensions of integrated circuit continue to shrink, diffraction based overlay (DBO) technologies have been developed to address the tighter overlay control challenges. Previously data of high accuracy and high precision were reported for litho-etch-litho-etch double patterning (DP) process using normal incidence spectroscopic reflectometry on specially designed targets composed of 1D gratings in x and y directions. Two measurement methods, empirical algorithm (eDBO) using four pads per direction (2x4 target) and modeling based algorithm (mDBO) using two pads per direction (2x2 target) were performed. In this work, we apply DBO techniques to measure overlay errors for a different DP process, litho-freeze-litho-etch process. We explore the possibility of further reducing number of pads in a DBO target using mDBO. For standard targets composed of 1D gratings, we reported results for eDBO 2x4 targets, mDBO 2x2 targets, and mDBO 2x1 target. The results of all three types of targets are comparable in terms of accuracy, dynamic precision, and TIS. TMU (not including tool matching) is less than 0.1nm. In addition, we investigated the possibility of measuring overlay with one single pad that contains 2D gratings. We achieved good correlation to blossom measurements. TMU (not including tool matching) is ~ 0.2nm. To our best knowledge, this is the first time that DBO results are reported on a single pad. eDBO allows quick recipe setup but takes more space and measurement time. Although mDBO needs details of optical properties and modeling, it offers smaller total target size and much faster throughput, which is important in high volume manufacturing environment.

A Measurement Study of the Structured Overlay Network in P2P File-Sharing Systems

Directory of Open Access Journals (Sweden)

Mo Zhou

2007-01-01

Full Text Available The architecture of P2P file-sharing applications has been developing to meet the needs of large scale demands. The structured overlay network, also known as DHT, has been used in these applications to improve the scalability, and robustness of the system, and to make it free from single-point failure. We believe that the measurement study of the overlay network used in the real file-sharing P2P systems can provide guidance for the designing of such systems, and improve the performance of the system. In this paper, we perform the measurement in two different aspects. First, a modified client is designed to provide view to the overlay network from a single-user vision. Second, the instances of crawler programs deployed in many nodes managed to crawl the user information of the overlay network as much as possible. We also find a vulnerability in the overlay network, combined with the character of the DNS service, a more serious DDoS attack can be launched.

[Study of the appearance difference of lower complete denture between functional and anatomic impression techniques].

Science.gov (United States)

Zhong, Qun; Wu, Xue-yin; Shen, Qing-yi; Shen, Qing-ping

2012-04-01

To compare the difference in oblique external ridge, oblique internal ridge and alveolar process crest of lower complete denture base made through functional impression and anatomic impression techniques. Fifteen patients were chosen to treat with two kinds of complete dentures through functional impression and anatomic impression technique respectively. 3D laser scanner was used to scan the three-dimensional model of the denture base and the differences of the surface structural between two techniques in alveolar process crest, external and internal oblique ridges were analyzed, using paired t test with SPSS 12.0 software package. Between the two techniques, there were significant differences in the areas of internal and external oblique ridge(P0.05). The results explain why there is less tenderness when functional impression technique is applied. The differences measured also indicate that sufficient buffering should be made in external and internal oblique ridge areas in clinic.

Pathogenic characteristics of Candida albicans isolated from oral cavities of denture wearers and cancer patients wearing oral prostheses.

Science.gov (United States)

Mothibe, J V; Patel, M

2017-09-01

Candida albicans cause opportunistic infections including oral candidiasis in immunocompromised patients. It has an ability to cause infection due to its virulence factors. This study investigated the pathogenic characteristics of C. albicans isolated from the oral cavities of healthy subjects and two vulnerable groups, denture wearers and cancer patients wearing oral prostheses. Oral rinse samples were collected and cultured for the quantitative and qualitative analysis of Candida. Twenty strains of C. albicans isolated from the healthy individuals and denture wearers and, 14 strains isolated from the cancer patients were selected and their pathogenic characteristics were measured. The results of the study groups were compared using a Scheffe test for pairwise comparison and a chi square test. Denture wearer and cancer patients with prostheses carried significantly higher number (p production were significantly higher in the strains from denture wearers. In addition, high number of isolates from the denture wearers produced phospholipase and proteinase (85% and 80% respectively) compared to the strains from normal subjects (25% and 60% respectively). Only the germ tube formation and adherence ability were significantly higher in the strains from the cancer patients with prostheses (p = 0.05 and p oral cavity and prostheses is important in the prevention of colonization of Candida and the development of oral candidiasis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Image-based overlay and alignment metrology through optically opaque media with sub-surface probe microscopy

Science.gov (United States)

van Es, Maarten H.; Mohtashami, Abbas; Piras, Daniele; Sadeghian, Hamed

2018-03-01

Nondestructive subsurface nanoimaging through optically opaque media is considered to be extremely challenging and is essential for several semiconductor metrology applications including overlay and alignment and buried void and defect characterization. The current key challenge in overlay and alignment is the measurement of targets that are covered by optically opaque layers. Moreover, with the device dimensions moving to the smaller nodes and the issue of the so-called loading effect causing offsets between between targets and product features, it is increasingly desirable to perform alignment and overlay on product features or so-called on-cell overlay, which requires higher lateral resolution than optical methods can provide. Our recently developed technique known as SubSurface Ultrasonic Resonance Force Microscopy (SSURFM) has shown the capability for high-resolution imaging of structures below a surface based on (visco-)elasticity of the constituent materials and as such is a promising technique to perform overlay and alignment with high resolution in upcoming production nodes. In this paper, we describe the developed SSURFM technique and the experimental results on imaging buried features through various layers and the ability to detect objects with resolution below 10 nm. In summary, the experimental results show that the SSURFM is a potential solution for on-cell overlay and alignment as well as detecting buried defects or voids and generally metrology through optically opaque layers.

Three-dimensional finite element analysis of implant-assisted removable partial dentures.

Science.gov (United States)

Eom, Ju-Won; Lim, Young-Jun; Kim, Myung-Joo; Kwon, Ho-Beom

2017-06-01

Whether the implant abutment in implant-assisted removable partial dentures (IARPDs) functions as a natural removable partial denture (RPD) tooth abutment is unknown. The purpose of this 3-dimensional finite element study was to analyze the biomechanical behavior of implant crown, bone, RPD, and IARPD. Finite element models of the partial maxilla, teeth, and prostheses were generated on the basis of a patient's computed tomographic data. The teeth, surveyed crowns, and RPDs were created in the model. With the generated components, four 3-dimensional finite element models of the partial maxilla were constructed: tooth-supported RPD (TB), implant-supported RPD (IB), tooth-tissue-supported RPD (TT), and implant-tissue-supported RPD (IT) models. Oblique loading of 300 N was applied on the crowns and denture teeth. The von Mises stress and displacement of the denture abutment tooth and implant system were identified. The highest von Mises stress values of both IARPDs occurred on the implants, while those of both natural tooth RPDs occurred on the frameworks of the RPDs. The highest von Mises stress of model IT was about twice that of model IB, while the value of model TT was similar to that of model TB. The maximum displacement was greater in models TB and TT than in models IB and IT. Among the 4 models, the highest maximum displacement value was observed in the model TT and the lowest value was in the model IB. Finite element analysis revealed that the stress distribution pattern of the IARPDs was different from that of the natural tooth RPDs and the stress distribution of implant-supported RPD was different from that of implant-tissue-supported RPD. When implants are used for RPD abutments, more consideration concerning the RPD design and the number or location of the implant is necessary. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Influence of high expansion dental stone used as investing medium on the changes in occlusal vertical dimension of complete dentures.

Science.gov (United States)

Salloum, Alaa'a M

2013-10-01

Despite advances in materials and techniques, complete dentures made of acrylic resin experience an increase in the occlusal vertical dimension (OVD) during processing. Many factors that affect the OVD of complete dentures are known. However, no study has examined the effect of using high-expansion dental stone (type V) as an investing material on the OVD. This study investigated the effects of using a high-expansion dental stone as an investing material on changes in the OVD of complete dentures. Twenty sets of simulated upper and lower dentures were processed by the compression molding technique. Specimens were equally divided into 2 groups. In the dental stone type III (DST III) group, the lower, middle, and upper parts of a flask were filled with DST III. In the dental stone type V (DST V) group, the procedure was the same as in the DST III group, except that the middle layer was made of high-expansion DST V. Changes in the OVD were measured before and after denture processing. Collected data were analyzed with t-test statistics. Differences were considered statistically significant at the 95% confidence level. Both groups showed a small increase in the OVD as a result of processing, but the OVD increase was significantly less in the DST V group compared to the DST III group. High-expansion DST V can be recommended as an investing material to reduce the increase in the OVD that may occur while processing complete dentures.

Measured residual stresses in overlay pipe weldments removed from service

International Nuclear Information System (INIS)

Shack, W.J.

1985-02-01

Surface and throughwall residual stresses were measured on an elbow-to-pipe weldment that had been removed from the Hatch-2 reactor about a year after the application of a weld overlay. The results were compared with experimental measurements on three mock-up weldments and with finite-element calculations. The comparison shows that there are significant differences in the form and magnitude of the residual stress distributions. However, even after more than a year of service, the residual stresses over most of the inner surface of the actual plant weldment with an overlay were strongly compressive. 3 refs., 7 figs

Cluster-assembled overlayers and high-temperature superconductors

International Nuclear Information System (INIS)

Ohno, T.R.; Yang, Y.; Kroll, G.H.; Krause, K.; Schmidt, L.D.; Weaver, J.H.; Kimachi, Y.; Hidaka, Y.; Pan, S.H.; de Lozanne, A.L.

1991-01-01

X-ray photoemission results for interfaces prepared by cluster assembly with nanometer-size clusters deposited on high-T c superconductors (HTS's) show a reduction in reactivity because atom interactions with the surface are replaced by cluster interactions. Results for conventional atom deposition show the formation of overlayer oxides that are related to oxygen depletion and disruption of the near-surface region of the HTS's. For cluster assembly of Cr and Cu, there is a very thin reacted region on single-crystal Bi 2 Sr 2 CaCu 2 O 8 . Reduced reactivity is observed for Cr cluster deposition on single-crystal YBa 2 Cu 3 O 7 -based interfaces. There is no evidence of chemical modification of the surface for Ge and Au cluster assembly on Bi 2 Sr 2 CaCu 2 O 8 (100). The overlayer grown by Au cluster assembly on Bi 2 Sr 2 CaCu 2 O 8 covers the surface at low temperature but roughening occurs upon warming to 300 K. Scanning-tunneling-microscopy results for the Au(cluster)/Bi 2 Sr 2 CaCu 2 O 8 system warmed to 300 K shows individual clusters that have coalesced into large clusters. These results offer insight into the role of surface energies and cluster interactions in determining the overlayer morphology. Transmission-electron-microscopy results for Cu cluster assembly on silica show isolated irregularly shaped clusters that do not interact at low coverage. Sintering and labyrinth formation is observed at intermediate coverage and, ultimately, a continuous film is achieved at high coverage. Silica surface wetting by Cu clusters demonstrates that dispersive force are important for these small clusters

Performance polymeric concrete with synthetic fiber reinforcement against reflective cracking in rigid pavement overlay

International Nuclear Information System (INIS)

Khan, N.U.; Khan, B.

2012-01-01

Cement concrete pavements are used for heavy traffic loads throughout the world owing to its better and economical performance. Placing of a concrete overlay on the existing pavement is the most prevalent rehabilitating method for such pavements, however, the problem associated with the newly placed overlay is the occurrence of reflective cracking. This paper presents an assessment of the performance of polymeric concrete with synthetic fiber reinforcement against reflective cracking in an overlay system. The performance of polymeric concrete with synthetic fibers as an overlay material is measured in terms of the load-deflection, strain-deflection and load-strain behavior of beams of the polymeric concrete. For this purpose, five types of beams having different number of fiber wires and position are tested for flexure strength. Deflection/strains for each increment of load are recorded. In addition, cubes of plain concrete and of concrete with synthetic fiber needles were tested after 7 and 28 days for compressive strengths. Finite element models in ANSYS software for the beams have also been developed. Beams with greater number of longitudinal fiber wires displayed relatively better performance against deflection whilst beams with synthetic fiber needles showed better performance against strains. Thus, polymeric concrete overlay with fiber reinforcement will serve relatively better against occurrence of reflective cracking. (author)

Efficacy of citric acid denture cleanser on the Candida albicans biofilm formed on poly(methyl methacrylate): effects on residual biofilm and recolonization process.

Science.gov (United States)

Faot, Fernanda; Cavalcanti, Yuri Wanderley; Mendonça e Bertolini, Martinna de; Pinto, Luciana de Rezende; da Silva, Wander José; Cury, Altair Antoninha Del Bel

2014-06-23

It is well known that the use of denture cleansers can reduce Candida albicans biofilm accumulation; however, the efficacy of citric acid denture cleansers is uncertain. In addition, the long-term efficacy of this denture cleanser is not well established, and their effect on residual biofilms is unknown. This in vitro study evaluated the efficacy of citric acid denture cleanser treatment on C. albicans biofilm recolonization on poly(methyl methacrylate) (PMMA) surface. C. albicans biofilms were developed for 72 h on PMMA resin specimens (n = 168), which were randomly assigned to 1 of 3 cleansing treatments (CTs) overnight (8 h). CTs included purified water as a control (CTC) and two experimental groups that used either a 1:5 dilution of citric acid denture cleanser (CT5) or a 1:8 dilution of citric acid denture cleanser (CT8). Residual biofilms adhering to the specimens were collected and quantified at two time points: immediately after CTs (ICT) and after cleaning and residual biofilm recolonization (RT). Residual biofilms were analyzed by quantifying the viable cells (CFU/mL), and biofilm architecture was evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Denture cleanser treatments and evaluation periods were considered study factors. Data were analyzed using two-way ANOVA and Tukey's Honestly Significant Difference (HSD) test (α = 0.05). Immediately after treatments, citric acid denture cleansing solutions (CT5 and CT8) reduced the number of viable cells as compared with the control (p recolonization (p recolonization was also detected by CLSM and SEM analysis, which revealed a higher biomass and average biofilm thickness for the CT8 group (p recolonization.

Successful Fitting of a Complete Maxillary Denture in a Patient with Severe Alzheimer’s Disease Complicated by Oral Dyskinesia

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Hiromitsu Morita

2016-01-01

Full Text Available There is an increasing population of elderly patients suffering from Alzheimer’s disease (AD, the most common form of dementia. In dentistry, a critical problem associated with these patients is the use of a new denture, as AD patients often refuse dental management and are disturbed by minor changes in their oral environment. Some AD patients have further complications associated with oral dyskinesia, a movement disorder that can make dental management difficult, including the stability of a complete denture. In this case, we successfully fitted a complete maxillary denture using modified bilateral balanced occlusion after multiple tooth extractions under intravenous sedation in a 66-year-old woman with severe AD complicated by oral dyskinesia. Following treatment, her appetite and food intake greatly improved. Providing a well-fitting complete denture applied by modified bilateral balanced occlusion, which removes lateral interference using zero-degree artificial teeth for movement disorder of the jaw in patients with severe AD complicated by oral dyskinesia, helps improve oral function.

Reinforcing effect of glass-fiber mesh on complete dentures in a test model with a simulated oral mucosa.

Science.gov (United States)

Yu, Sang-Hui; Oh, Seunghan; Cho, Hye-Won; Bae, Ji-Myung

2017-11-01

Studies that evaluated the strength of complete dentures reinforced with glass-fiber mesh or metal mesh on a cast with a simulated oral mucosa are lacking. The purpose of this in vitro study was to compare the mechanical properties of maxillary complete dentures reinforced with glass-fiber mesh with those of metal mesh in a new test model, using a simulated oral mucosa. Complete dentures reinforced with 2 types of glass-fiber mesh, SES mesh (SES) and glass cloth (GC) and metal mesh (metal) were fabricated. Complete dentures without any reinforcement were prepared as a control (n=10). The complete dentures were located on a cast with a simulated oral mucosa, and a load was applied on the posterior artificial teeth bilaterally. The fracture load, elastic modulus, and toughness of a complete denture were measured using a universal testing machine at a crosshead speed of 5 mm/min. The fracture load and elastic modulus were analyzed using 1-way analysis of variance, and the toughness was analyzed with the Kruskal-Wallis test (α=.05). The Tukey multiple range test was used as a post hoc test. The fracture load and toughness of the SES group was significantly higher than that of the metal and control groups (P<.05) but not significantly different from that of the GC group. The elastic modulus of the metal group was significantly higher than that of the control group (P<.05), and no significant differences were observed in the SES and GC groups. Compared with the control group, the fracture load and toughness of the SES and GC groups were higher, while those of the metal group were not significantly different. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

The effect of submersion denture base acrylic resin in a betel leaf ekstract solution against growth Candida albicans

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Andi Izham

2016-06-01

Full Text Available Denture base is a protesa which replace some or all of the lost original teeth and surrounding tissues. The Pupose of making protesa is for restore the function, appearance, comfort and impaired health result lost teeth. One part of the denture base is base plate. Microorganisms are often found in the oral cavity is Candida albicans (C.albicans approximately 40% in the oral cavity.C.albicans can penetrate the acrylic resin that can infect the soft tissue and is the cause of denture stomatitis therefore the disinfection of denture base is a important factor that must be done. In general betel leaves contant up to 4.2% essential oil compounds and phenyl propanoid and tannin. These compounds is a antimicroba and antifungal which can inhibit the growth of several type of bacteria among others Escherichia coli, Salmonella sp, Staphylococcus aurens, Klebstella, Pasteurella and can turn off the C.albicans. The purpose of the research is to determine how the effect of submersion denture base acrylic resin in a betel leaf ekstract solution against growth C.albicans.Type of research is an experimental laboratory with a longitudinal design (follow-up study. The sampling method used is total sampling. The results showed that the number of C.albicans colonies n denture base acrylic resin which soaked betel leaf extract solution that the dilution 10-1  with consentration 2.5% total colony count is 2 and the results 2.0 x 101 CFU/ml, on a control solution that the dilution 10-2 total colony 355 and the result 3.55 x 104 CFU/ml, that the dilution  10-3 total colony 62 and the result 6.2 x 104 CFU/ml.

Patient satisfaction with laser-sintered removable partial dentures: A crossover pilot clinical trial.

Science.gov (United States)

Almufleh, Balqees; Emami, Elham; Alageel, Omar; de Melo, Fabiana; Seng, Francois; Caron, Eric; Nader, Samer Abi; Al-Hashedi, Ashwaq; Albuquerque, Rubens; Feine, Jocelyne; Tamimi, Faleh

2018-04-01

Clinical data regarding newly introduced laser-sintered removable partial dentures (RPDs) are needed before this technique can be recommended. Currently, only a few clinical reports have been published, with no clinical studies. This clinical trial compared short-term satisfaction in patients wearing RPDs fabricated with conventional or computer-aided design and computer-aided manufacturing (CAD-CAM) laser-sintering technology. Twelve participants with partial edentulism were enrolled in this pilot crossover double-blinded clinical trial. Participants were randomly assigned to wear cast or CAD-CAM laser-sintered RPDs for alternate periods of 30 days. The outcome of interest was patient satisfaction as measured using the McGill Denture Satisfaction Instrument. Assessments was conducted at 1, 2, and 4 weeks. The participant's preference in regard to the type of prosthesis was assessed at the final evaluation. The linear mixed effects regression models for repeated measures were used to analyze the data, using the intention-to-treat principle. To assess the robustness of potential, incomplete adherence, sensitivity analyses were conducted. Statistically significant differences were found in patients' satisfaction between the 2 methods of RPD fabrication. Participants were significantly more satisfied with laser-sintered prostheses than cast prostheses in regard to general satisfaction, ability to speak, ability to clean, comfort, ability to masticate, masticatory efficiency, and oral condition (Premovable partial dentures may lead to better outcomes in terms of patient satisfaction in the short term. The conclusion from this pilot study requires confirmation by a larger randomized controlled trial. ClinicalTrials.gov. A study about patient satisfaction with laser-sintered removable partial dentures; NCT02769715. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Cytotoxic effects of denture adhesives on primary human oral keratinocytes, fibroblasts and permanent L929 cell lines.

Science.gov (United States)

Chen, Fengying; Wu, Tianfu; Cheng, Xiangrong

2014-03-01

To date, there have been very little data on the cytotoxic responses of different cell lines to denture adhesives. To determine the cytotoxicity of three denture adhesives on primary human oral keratinocytes (HOKs), fibroblasts (HOFs) and permanent mouse fibroblasts cell lines (L929). Three commercial denture adhesives (two creams and one powder) were prepared for indirect contact using the agar diffusion test, as well as extracts in MTT assay. The results of the MTT assay were statistically analysed by one-way anova and Tukey's test (p adhesives showed mild to moderate cytotoxicity to primary HOKs (p  0.05) in both assays. For primary HOFs cultures, slight cytotoxicity was observed for one of the products from the agar diffusion test and undiluted eluates of all tested adhesives with MTT assay (p adhesives are toxic to the primary HOKs and HOFs cultures, whereas non-toxic to L929 cells. The results suggest that primary human oral mucosal cells may provide more valuable information in toxicity screening of denture adhesives. © 2012 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

Developing a software for removable partial denture design: Part II: Introduction of RPD graph software

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Nejatidanesh F

2007-06-01

Full Text Available Background and Aim: Designing removable partial dentures is one of the most important phases of prosthetic treatments. Computer can be used to facilitate and increase accuracy of removable partial denture design. The aim of this study was to develop a software for removable partial denture design.Materials and Methods: A questionnaire (discussed in part I and major textbooks, were used to determine the design rules.  The software (RPD Graph was developed using Visual C++ and Maryam program. The RPD Graph can determine the classification of partial edentulous arch. With defining the missing teeth and providing data about prognosis and conditions of abutment teeth, the removable partial design will be developed by RPD Graph. This software is a knowledge-based system which has specific characteristics. It can be used as an educational tool for teaching RPD design and as a clinical tool for supporting clinician's decision. In addition it can be developed to more complete softwares.

Using the overlay assay to qualitatively measure bacterial production of and sensitivity to pneumococcal bacteriocins.

Science.gov (United States)

Maricic, Natalie; Dawid, Suzanne

2014-09-30

Streptococcus pneumoniae colonizes the highly diverse polymicrobial community of the nasopharynx where it must compete with resident organisms. We have shown that bacterially produced antimicrobial peptides (bacteriocins) dictate the outcome of these competitive interactions. All fully-sequenced pneumococcal strains harbor a bacteriocin-like peptide (blp) locus. The blp locus encodes for a range of diverse bacteriocins and all of the highly conserved components needed for their regulation, processing, and secretion. The diversity of the bacteriocins found in the bacteriocin immunity region (BIR) of the locus is a major contributor of pneumococcal competition. Along with the bacteriocins, immunity genes are found in the BIR and are needed to protect the producer cell from the effects of its own bacteriocin. The overlay assay is a quick method for examining a large number of strains for competitive interactions mediated by bacteriocins. The overlay assay also allows for the characterization of bacteriocin-specific immunity, and detection of secreted quorum sensing peptides. The assay is performed by pre-inoculating an agar plate with a strain to be tested for bacteriocin production followed by application of a soft agar overlay containing a strain to be tested for bacteriocin sensitivity. A zone of clearance surrounding the stab indicates that the overlay strain is sensitive to the bacteriocins produced by the pre-inoculated strain. If no zone of clearance is observed, either the overlay strain is immune to the bacteriocins being produced or the pre-inoculated strain does not produce bacteriocins. To determine if the blp locus is functional in a given strain, the overlay assay can be adapted to evaluate for peptide pheromone secretion by the pre-inoculated strain. In this case, a series of four lacZ-reporter strains with different pheromone specificity are used in the overlay.

Visualization of disciplinary profiles: Enhanced science overlay maps

NARCIS (Netherlands)

Carley, S.; Porter, A.L.; Rafols, I.; Leydesdorff, L.

Purpose The purpose of this study is to modernize previous work on science overlay maps by updating the underlying citation matrix, generating new clusters of scientific disciplines, enhancing visualizations, and providing more accessible means for analysts to generate their own maps.

Effect of SiO2 Overlayer on WO3 Sensitivity to Ammonia

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Vibha Srivastava

2010-06-01

Full Text Available Ammonia gas sensing properties of tungsten trioxide thick film sensor was investigated. The doping of noble catalysts such as Pt, Pd, Au enhanced the gas sensitivity. Platinum doping was found to result in highest sensitivity. Remarkable sensitivity enhancement was realized by coating WO3 thick film sensors with SiO2 overlayer. Sol gel process derived silica overlayer increased ammonia gas sensitivity for doped as well as undoped sensor.

Digitizing geographic data with GRIDOT; a generalized program for drawing overlay grids in various map projections

International Nuclear Information System (INIS)

Edwards, R.G.; Durfee, R.C.

1976-09-01

The GRIDOT computer program draws overlay grids on a Calcomp plotter for use in digitizing information from maps, rectified aerial photographs, and other sources of spatially distributed data related to regional environmental problems. The options of the program facilitate use of the overlays with standard maps and map projections of the continental United States. The overlay grid may be defined as a latitude-longitude grid (geodetic grid), a Universal Transverse Mercator Grid, or one of the standard state-plane coordinate system grids. The map for which the overlay is intended may be in an Albers Equal Area projection, a Lambert Conformal projection, a Polyconic projection, a Transverse Mercator projection, a Universal Transverse Mercator projection, or any of the standard state-plane projections

PULPAL BLOOD FLOW CHANGES IN ABUTMENT TEETH OF REMOVABLE PARTIAL DENTURES

Science.gov (United States)

Kunt, Göknil Ergün; Kökçü, Deniz; Ceylan, Gözlem; Yılmaz, Nergiz; Güler, Ahmet Umut

2009-01-01

The purpose of this study was to investigate the effect of tooth supported (TSD) and toothtissue supported (TTSD) removable partial denture wearing on pulpal blood flow (PBF) of the abutment teeth by using Laser Doppler Flowmeter (LDF). Measurements were carried out on 60 teeth of 28 patients (28 teeth and 12 patients of TTSD group, 32 teeth and 16 patients of TSD group) who had not worn any type of removable partial dentures before, had no systemic problems and were non smokers. PBF values were recorded by LDF before insertion (day 0) and after insertion of dentures at day 1, day 7 and day 30. Statistical analysis was performed by student t test and covariance analyses of repeated measurements. In the group TTSD, the mean values of PBF decreased statistically significantly at day 1 after insertion when compared with PBF values before insertion (p<0,01). There was no statistically significant difference among PBF mean values on 1st, 7th and 30th day. However, in the group TSD, there was no statistically significant difference among PBF mean values before insertion and on 1st, 7th and 30th day. In other words, PBF mean values in group TSD continued without changing statistically significant on 1st, 7th and 30th day. TTSD wearing may show negative effect on the abutment teeth due to decreasing basal PBF. PMID:20001995

Pulpal blood flow changes in abutment teeth of removable partial dentures

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Göknil Ergün Kunt

2009-11-01

Full Text Available The purpose of this study was to investigate the effect of tooth supported (TSD and toothtissue supported (TTSD removable partial denture wearing on pulpal blood flow (PBF of the abutment teeth by using Laser Doppler Flowmeter (LDF.Measurements were carried out on 60 teeth of 28 patients (28 teeth and 12 patients of TTSD group, 32 teeth and 16 patients of TSD group who had not worn any type of removable partial dentures before, had no systemic problems and were non smokers. PBF values were recorded by LDF before insertion (day 0 and after insertion of dentures at day 1, day 7 and day 30. Statistical analysis was performed by student t test and covariance analyses of repeated measurements.In the group TTSD, the mean values of PBF decreased statistically significantly at day 1 after insertion when compared with PBF values before insertion (p<0,01. There was no statistically significant difference among PBF mean values on 1st, 7th and 30th day. However, in the group TSD, there was no statistically significant difference among PBF mean values before insertion and on 1st, 7th and 30th day. In other words, PBF mean values in group TSD continued without changing statistically significant on 1st, 7th and 30th day.TTSD wearing may show negative effect on the abutment teeth due to decreasing basal PBF.

Colour stability of denture teeth submitted to different cleaning protocols and accelerated artificial aging.

Science.gov (United States)

Freire, T S; Aguilar, F G; Garcia, L da Fonseca Roberti; Pires-de-Souza, F de Carvalho Panzeri

2014-03-01

Acrylic resin is widely used for artificial teeth manufacturing due to several important characteristics; however, this material do not present acceptable colour stability over the course of time. This study evaluated the effect of different cleaning protocols and accelerated artificial aging on colour stability of denture teeth made of acrylic resin. Sixty denture teeth in dark and light shades were used, and separated according to the treatment to which they were submitted. Results demonstrated that colour stability of artificial teeth is influenced by the cleaning solution and artificial aging, being dark teeth more susceptible to colour alteration than lighter ones.

Is the goal of mastication reached in young dentates, aged dentates and aged denture wearers?

Science.gov (United States)

Mishellany-Dutour, Anne; Renaud, Johanne; Peyron, Marie-Agnès; Rimek, Frank; Woda, Alain

2008-01-01

The objective of the present study was to assess the impact of age and dentition status on masticatory function. A three-arm case-control study was performed. Group 1 (n 14) was composed of young fully dentate subjects (age 35.6 +/- 10.6 years), group 2 (n 14) of aged fully dentate subjects (age 68.8 +/- 7.0 years) and group 3 (n 14) of aged full denture wearers (age 68.1 +/- 7.2 years). Mastication adaptation was assessed in the course of chewing groundnuts and carrots to swallowing threshold. Particle size distribution of the chewed food, electromyographic (EMG) activity of the masseter and temporalis muscles during chewing, and resting and stimulated whole saliva rates were measured. Aged dentate subjects used significantly more chewing strokes to reach swallowing threshold than younger dentate subjects (P < 0.05), with increased particle size reduction, longer chewing sequence duration (P < 0.05) and greater total EMG activity (P < 0.05) for both groundnuts and carrots. In addition, aged denture wearers made significantly more chewing strokes than aged dentate subjects (P < 0.001) to reach swallowing threshold for groundnuts. Particle size reduction at time of swallowing was significantly poorer for denture wearers than for their aged dentate counterparts, despite an increase in chewing strokes, sequence duration and EMG activity per sequence. Masticatory function was thus adapted to ageing, but was impaired in denture wearers, who failed to adapt fully to their deficient masticatory apparatus.

Visually assessed colour overlay features in shear-wave elastography for breast masses: quantification and diagnostic performance.

Science.gov (United States)

Gweon, Hye Mi; Youk, Ji Hyun; Son, Eun Ju; Kim, Jeong-Ah

2013-03-01

To determine whether colour overlay features can be quantified by the standard deviation (SD) of the elasticity measured in shear-wave elastography (SWE) and to evaluate the diagnostic performance for breast masses. One hundred thirty-three breast lesions in 119 consecutive women who underwent SWE before US-guided core needle biopsy or surgical excision were analysed. SWE colour overlay features were assessed using two different colour overlay pattern classifications. Quantitative SD of the elasticity value was measured with the region of interest including the whole breast lesion. For the four-colour overlay pattern, the area under the ROC curve (Az) was 0.947; with a cutoff point between pattern 2 and 3, sensitivity and specificity were 94.4 % and 81.4 %. According to the homogeneity of the elasticity, the Az was 0.887; with a cutoff point between reasonably homogeneous and heterogeneous, sensitivity and specificity were 86.1 % and 82.5 %. For the SD of the elasticity, the Az was 0.944; with a cutoff point of 12.1, sensitivity and specificity were 88.9 % and 89.7 %. The colour overlay features showed significant correlations with the quantitative SD of the elasticity (P < 0.001). The colour overlay features and the SD of the elasticity in SWE showed excellent diagnostic performance and showed good correlations between them.

On the influence of latency estimation on dynamic group communication using overlays

Science.gov (United States)

Vik, Knut-Helge; Griwodz, Carsten; Halvorsen, Pål

2009-01-01

Distributed interactive applications tend to have stringent latency requirements and some may have high bandwidth demands. Many of them have also very dynamic user groups for which all-to-all communication is needed. In online multiplayer games, for example, such groups are determined through region-of-interest management in the application. We have investigated a variety of group management approaches for overlay networks in earlier work and shown that several useful tree heuristics exist. However, these heuristics require full knowledge of all overlay link latencies. Since this is not scalable, we investigate the effects that latency estimation techqniues have ton the quality of overlay tree constructions. We do this by evaluating one example of our group management approaches in Planetlab and examing how latency estimation techqniues influence their quality. Specifically, we investigate how two well-known latency estimation techniques, Vivaldi and Netvigator, affect the quality of tree building.

Effect of Reinforcement Using Stainless Steel Mesh, Glass Fibers, and Polyethylene on the Impact Strength of Heat Cure Denture Base Resin - An In Vitro Study.

Science.gov (United States)

Murthy, H B Mallikarjuna; Shaik, Sharaz; Sachdeva, Harleen; Khare, Sumit; Haralur, Satheesh B; Roopa, K T

2015-06-01

The impact strength of denture base resin is of great concern and many approaches have been made to strengthen acrylic resin dentures. The objective of this study was to compare the impact strength of the denture base resin with and without reinforcement and to evaluate the impact strength of denture base resin when reinforced with stainless steel mesh, glass fiber, and polyethylene fibers in the woven form. The specimens (maxillary denture bases) were fabricated using a standard polyvinylsiloxane mold with conventional heat cured polymethyl methacrylate resin. The specimens were divided into four groups (n = 10). Group I specimens or control group were not reinforced. Group II specimens were reinforced with stainless steel mesh and Group III and Group IV specimens were reinforced with three percent by weight of glass fibers and polyethylene fibers in weave form respectively. All the specimens were immersed in water for 1-week before testing. The impact strength was measured with falling weight impact testing machine. One-way analysis of variance and Tukey's post-hoc test were used for statistical analysis. Highest impact strength values were exhibited by the specimens reinforced with polyethylene fibers followed by glass fibers, stainless steel mesh, and control group. Reinforcement of maxillary complete dentures showed a significant increase in impact strength when compared to unreinforced dentures. Polyethylene fibers exhibit better impact strength followed by glass fibers and stainless steel mesh. By using pre-impregnated glass and polyethylene fibers in woven form (prepregs) the impact strength of the denture bases can be increased effectively.

[Influence of attachment type on stress distribution of implant-supported removable partial dentures].

Science.gov (United States)

Yang, Xue; Rong, Qi-guo; Yang, Ya-dong

2015-02-18

To compare influences of different retention attachments on stress among supporting structures. By 3-dimensional laser scanner and reverse engineering computer aided design (CAD) software, a basic partially edentulous digital model with mandibular premolar and molar missing was established. Implant attachment and removable partial dentures (RPD) were added into the basic model to build three kinds of models: RPD only, RPD + implant + Locator attachment, and RPD + implant + Magfit attachment. Vertical and inclined loads were put on artificial teeth unilaterally. By means of 3-dimensional finite element analysis, the stress distribution and displacement of the main supportive structures were compared. A complete 3-dimensional finite element model was established, which contained tooth structure, and periodontal structures. The displacement of the denture was smaller in Locator (9.38 μm vertically, 45.48 μm obliquely) and Magfit models (9.54 μm vertically, 39.45 μm obliquely) compared with non-implant RPD model (95.27 μm vertically, 155.70 μm obliquely). Compared with the two different attachments, cortical bone stress value was higher in Locator model (Locator model 10.850 MPa vertically, 43.760 MPa obliquely; Magfit model 7.100 MPa vertically, 19.260 MPa obliquely).The stress value of abutment periodontal ligamentin Magfit model (0.420 MPa vertically) was lower than that in Locator model (0.520 MPa vertically). The existence of implant could reduce maximum von Mises value of each supportive structure when Kennedy I partially edentulous mandible was restored. Comparing the structure of Magfit and Locator attachment, the contact of Magfit attachment was rigid, while Locator was resilient. Locator attachment could improve stability of the denture dramatically. Locator had stronger effect on defending horizontal movement of the denture.

Functional Impressions in Complete Denture and Overdenture Treatment

OpenAIRE

Hrvoje Kršek; Nikša Dulčić

2015-01-01

Tooth loss can cause loss of occlusal, masticatory, esthetic, physiognomic, phonetic and psychosocial function of patients. The most frequently used treatment method of completely edentulous patients and patients with a small number of remaining teeth are complete dentures or overdentures. One of the most important clinical and laboratory procedures in their fabrication is functional impression taking. The aim of this paper was to present procedures of taking functional impressions in fab...

Clinical and microbiologic effects of lingual cervical coverage by removable partial dentures.

Science.gov (United States)

Ao, Aiichiro; Wakabayashi, Noriyuki; Nitta, Hiroshi; Igarashi, Yoshimasa

2013-01-01

The effect of gingival coverage by removable partial dentures (RPDs) on bacterial accumulation has not been sufficiently established. The aim of this study was to evaluate the periodontal and microbiologic reactions to mandibular major connectors. It was hypothesized that the use of a lingual plate increases the risk of periodontal disease. Fourteen subjects (mean age: 69.0 years) received oral hygiene instructions and ultrasonic debridement prior to examination. Each subject received an experimental RPD incorporating either a lingual bar or lingual plate for the first 8 weeks and was then switched to the other option for the next 8 weeks. Clinical parameters (Plaque Index, Gingival Index, probing depth, and tooth mobility) were recorded. Subgingival plaque samples were collected from the periodontal pocket in the test site to measure the colonization of periodontal pathogens after the use of each denture. The mean probing depth was significantly greater after use of the lingual plate compared to the lingual bar (P bacterial species showed smaller numbers of microorganisms at the second examination than at the first. The lingual cervical coverage did not precipitate the accumulation of anaerobic microorganisms, although it could potentially induce gingival inflammation. The results suggest that a lingual plate can be used as safely as a lingual bar if oral and denture hygiene are carefully monitored.

Removable partial dentures: clinical concepts.

Science.gov (United States)

Bohnenkamp, David M

2014-01-01

This article provides a review of the traditional clinical concepts for the design and fabrication of removable partial dentures (RPDs). Although classic theories and rules for RPD designs have been presented and should be followed, excellent clinical care for partially edentulous patients may also be achieved with computer-aided design/computer-aided manufacturing technology and unique blended designs. These nontraditional RPD designs and fabrication methods provide for improved fit, function, and esthetics by using computer-aided design software, composite resin for contours and morphology of abutment teeth, metal support structures for long edentulous spans and collapsed occlusal vertical dimensions, and flexible, nylon thermoplastic material for metal-supported clasp assemblies. Copyright © 2014 Elsevier Inc. All rights reserved.