Sample records for partial denture wearers

  1. Swallowed partial dentures

    PubMed Central

    Hashmi, Syed; Walter, John; Smith, Wendy; Latis, Sergios

    2004-01-01

    Swallowed or inhaled partial dentures can present a diagnostic challenge. Three new cases are described, one of them near-fatal because of vascular erosion and haemorrhage. The published work points to the importance of good design and proper maintenance. The key to early recognition is awareness of the hazard by denture-wearers, carers and clinicians. PMID:14749401

  2. Malodour in denture wearers: an ill-defined problem.

    PubMed

    Verran, J

    2005-01-01

    Denture plaque has not been studied to the same extent as dental plaque, and although there are many similarities in microbial composition, there are some significant differences. Denture-induced stomatitis is associated with poor denture hygiene, a more acidogenic plaque and the presence of Candida albicans. Obligate Gram-negative anaerobic micro-organisms, although present in denture plaque, have rarely been specifically investigated. Opportunist pathogens including coliforms and staphylococci have been isolated from dentures. Teeth adjacent to partial dentures are more susceptible to caries and periodontal diseases, perhaps due to an increased plaque buildup at the prosthesis/tooth interface. Little work has been published on malodour associated with dentures. The inert material provides a substratum for the plaque biofilm, which encompasses a range of odour-producing species. The microbiology of the tongue in denture wearers has not been specifically studied. Thus the nature, origin and extent of malodour in denture wearers is ill-defined, but many species capable of producing malodorous compounds are present. The wide age and health range presented by denture wearers further confounds investigation. There is a need for further work in the area, both for cosmetic- and health-associated reasons in the increasing elderly population. PMID:15752093

  3. Satisfaction of the complete denture wearers related to various factors.

    PubMed

    Turker, Sebnem Begum; Sener, I?il Damla; Ozkan, Yasemin Kulak

    2009-01-01

    All dentists who have worked with complete denture wearers know that patient satisfaction is not based only on the technical quality of the dentures. The aim of this study was at assessing the effect of gender, the number of the dentures used before, the length of time of denture usage, education and age on the satisfaction of the complete denture wearers. The students of the Dental Faculty of Marmara University (Turkey) made new dentures for 342 patients who were asked to participate in the investigation. The subjects (137 men and 205 women) were 39-89 years of age with a mean of 61.62 years. The attitude toward dentures in general was measured by means of 11 items of a questionnaire. The 10 main questions of the questionnaire were answered by the participants, and quantified on a 7-point scale, while the 11th issue (general satisfaction) was evaluated on a scale of 1-10. All main factors were also estimated in subgroups. For example, the education was analyzed in 4 subgroups, the time of denture usage was divided into two subgroups (below and above 3 years) and the number of dentures used before was also taken as up to 3 or more than 3 dentures. The age of the subjects was taken in 3 subgroups: 40-55, 56-65 and >65 years. One-way ANOVA, Tukey and Student t-tests were used to evaluate the answers to the questionnaire. Our patients displayed statistically significant differences only in the topics of their ability of cleaning their dentures, due to education and number of previously used dentures. PMID:19117618

  4. Self-reported denture hygiene habits and oral tissue conditions of complete denture wearers.

    PubMed

    Baran, Ilgi; Nalçaci, Rana

    2009-01-01

    The aim of the study was to examine the influence of denture hygiene on the development and intensity of denture stomatitis and traumatic ulcers and their relationship to age, gender, educational level, smoking status, age of the denture, denture hygiene habits and denture-wearing behavior. The study population comprised 310 complete denture (CD) wearers (159 males and 151 females) aged 60-85 living in Kirikkale, Turkey. Denture hygiene habits were assessed and recorded, and any relationships between denture hygiene habits and the condition of oral tissue were assessed. The majority (48.4%) of participants reported cleaning their dentures with a toothbrush and toothpaste and 45.2% with a toothbrush only. Less than half (44.8%) removed their dentures overnight. Stomatitis was observed in 35.8% and traumatic ulcers in 29% of patients. A positive relationship was observed between poor denture hygiene habits and the presence of denture-related stomatitis and traumatic ulcers. The degree of denture hygiene was significantly associated with age, sex, education, general health status, smoking status, self-perception of halitosis, overnight denture removal and denture immersion habits. PMID:18976822

  5. Behaviors and hygiene habits of complete denture wearers.

    PubMed

    Peracini, Amanda; Andrade, Ingrid Machado de; Paranhos, Helena de Freitas Oliveira; Silva, Cláudia Helena Lovato da; de Souza, Raphael Freitas

    2010-01-01

    In this study, a questionnaire was applied to patients from Ribeirão Preto Dental School, University of São Paulo, Brazil, to evaluate the hygiene methods and habits concerning the use of complete dentures, the age of dentures, and whether patients have been instructed on how to clean their dentures. The mean age of patients was 63.35 years, and most of them were females (82.08%). The results showed that 62.26% of the respondents had been using the same maxillary complete denture for more than 5 years, and 49.06% used the same mandible complete denture for more than 5 years. Of the patients interviewed, 58.49% slept with the dentures. Mechanical brushing was the most used cleaning method by the patients (100%), using water, dentifrice and toothbrush (84.91%). Most patients (51.89%) reported never having been instructed by their dentists as to how to clean their dentures. Based on the limitations of this study, it was concluded that the patients interviewed had limited knowledge about prosthetic hygiene and oral care. The method more used by patients was the mechanical method of brushing, most patients used the same complete dentures for more than 5 years and slept with the dentures. PMID:21203709

  6. VINEGAR AS AN ANTIMICROBIAL AGENT FOR CONTROL OF Candida spp. IN COMPLETE DENTURE WEARERS

    PubMed Central

    Pinto, Telma Maria Silva; Neves, Ana Christina Claro; Leão, Mariella Vieira Pereira; Jorge, Antonio Olavo Cardoso

    2008-01-01

    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. PMID:19082396

  7. Antifungal suscepitibility profile of candida spp. oral isolates obtained from denture wearers

    PubMed Central

    Lyon, J.P.; Moreira, L.M.; Cardoso, M.A.G.; Saade, J.; Resende, M.A.

    2008-01-01

    Denture stomatitis is an inflammatory condition that occurs in denture wearers and is frequently associated with Candida yeasts. Antifungal susceptibility profiles have been extensively evaluated for candidiasis patients or immunosupressed individuals, but not for healthy Candida carriers. In the present study, fluconazole, itraconazole, voriconazole, terbinafine and 5-flucytosin were tested against 109 oral Candida spp. isolates. All antifungal agents were effective against the samples tested except for terbinafine. This work might provide epidemiological information about Candida spp. drug susceptibility in oral healthy individuals. PMID:24031286

  8. Maximum bite force in elderly indigenous and non-indigenous denture wearers.

    PubMed

    Borie, Eduardo; Orsi, Iara A; Fuentes, Ramón; Beltrán, Víctor; Navarro, Pablo; Pareja, Felipe; Raimundo, Lariça B

    2014-01-01

    The aim of this study was to compare the measures of maximum bite force (MBF) in elderly edentulous indigenous (Mapuche) and non-indigenous individuals with new complete dentures at two different measuring times. A sample of 100 elderly subjects was divided into two groups: 50 indigenous and 50 non-indigenous, each including 25 females and 25 males. All individuals were totally edentulous, with new maxillary and mandibular removable complete dentures. Measurements were taken at the time of new prosthesis placement and after 1 month of use. Subjects were asked to perform with maximum effort three bites per side at maximum intercuspidation, with a rest time of 2 minutes in between. Statistics were analyzed with Student 's t-test. The MBF values were significantly higher in indigenous than non-indigenous subjects. Force after 1 month of wearing the new prosthesis was significantly higher than at the time of new prosthesis placement. No significant difference was found between sides. Elderly indigenous complete denture wearers had the greatest MBF values. Denture wearers were observed to undergo an adaptation process to the new prosthesis, with MBF increasing considerably after one month of use. PMID:25560689

  9. In vitro activities of natural products against oral Candida isolates from denture wearers

    PubMed Central

    2011-01-01

    Background Candida-associated denture stomatitis is a frequent infectious disease. Treatment of this oral condition is difficult because failures and recurrences are common. The aim of this study was to test the in vitro antifungal activity of pure constituents of essentials oils. Methods Eight terpenic derivatives (carvacrol, farnesol, geraniol, linalool, menthol, menthone, terpinen-4-ol, and ?-terpineol), a phenylpropanoid (eugenol), a phenethyl alcohol (tyrosol) and fluconazole were evaluated against 38 Candida isolated from denture-wearers and 10 collection Candida strains by the CLSI M27-A3 broth microdilution method. Results Almost all the tested compounds showed antifungal activity with MIC ranges of 0.03-0.25% for eugenol and linalool, 0.03-0.12% for geraniol, 0.06-0.5% for menthol, ?-terpineol and terpinen-4-ol, 0.03-0.5% for carvacrol, and 0.06-4% for menthone. These compounds, with the exception of farnesol, menthone and tyrosol, showed important in vitro activities against the fluconazole-resistant and susceptible-dose dependent Candida isolates. Conclusions Carvacrol, eugenol, geraniol, linalool and terpinen-4-ol were very active in vitro against oral Candida isolates. Their fungistatic and fungicidal activities might convert them into promising alternatives for the topic treatment of oral candidiasis and denture stomatitis. PMID:22118215

  10. Dentures

    MedlinePLUS

    ... meant to blend into the existing gum, with prosthetic teeth to replace the missing teeth. Full Dentures ... similar to partial dentures in that they are prosthetic teeth and gums used to replace missing teeth. ...

  11. [Prevention: the success of a partial denture].

    PubMed

    van Loveren, C

    2009-11-01

    After the placement of removable partial dentures, additional caries and periodontal problems may arise in the remaining dentition. These problems are the result of insufficient oral hygiene. Oral hygiene may be hampered by wearing the removable partial denture. The design of the removable partial denture should be carried out according to modern concepts of preventive dentistry. Before placing a removable partial denture, the patient's mouth should be thoroughly healthy and the patient should be instructed properly on adequate oral care. Furthermore, the patient should be aware of his/her own responsibility for maintenance. If cleaning twice a day with fluoride tooth-paste provides insufficient protection, care can be supported by daily use of a fluoride containing antimicrobial mouthrinse. Little effect can be expected from professionally applied fluoride or chlorhexidine solutions. PMID:19999672

  12. [Designing metal frame removable partial dentures].

    PubMed

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

    2011-02-01

    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 should have good stability and retention. The designing process follows several phases without a strict chronological sequence. If it is necessary to return to a previous phase, the process follows a circular sequence. The usual phases are evaluating dental arch study casts, examining diagnostic set-ups, selecting abutment teeth, surveying dental arch study casts, selecting the major connector, selecting minor connector and clasp types, selecting artificial teeth, modifying the denture design from theoretically ideal towards practically optimal, and carrying out the intended tooth preparations in a dental arch study cast. Tooth preparations in the working cast together with a denture design prescription will provide the dental technician with the information needed for manufacturing the metal frame removable partial denture. PMID:21438358

  13. Rapid manufacture of removable partial denture frameworks

    Microsoft Academic Search

    Richard Bibb; Dominic Eggbeer; Robert Williams

    2006-01-01

    Purpose – The aim of this study was to explore the application of rapid manufacturing (RM) to the production of patient specific, custom-fitting removable partial denture (RPD) alloy frameworks. RPDs are metal frameworks designed to retain artificial replacement teeth in the oral cavity. Design\\/methodology\\/approach – The study was undertaken by applied case study. An RPD was designed using computer-aided design

  14. 21 CFR 872.3600 - Partially fabricated denture kit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3600 Partially fabricated denture kit. (a) Identification. A partially fabricated...

  15. Multiple Logistic Regression Analysis of Risk Factors Associated with Denture Plaque and Staining in Chinese Removable Denture Wearers over 40 Years Old in Xi’an – a Cross-Sectional Study

    PubMed Central

    Chai, Zhiguo; Chen, Jihua; Zhang, Shaofeng

    2014-01-01

    Background Removable dentures are subject to plaque and/or staining problems. Denture hygiene habits and risk factors differ among countries and regions. The aims of this study were to assess hygiene habits and denture plaque and staining risk factors in Chinese removable denture wearers aged >40 years in Xi’an through multiple logistic regression analysis (MLRA). Methods Questionnaires were administered to 222 patients whose removable dentures were examined clinically to assess wear status and levels of plaque and staining. Univariate analyses were performed to identify potential risk factors for denture plaque/staining. MLRA was performed to identify significant risk factors. Results Brushing (77.93%) was the most prevalent cleaning method in the present study. Only 16.4% of patients regularly used commercial cleansers. Most (81.08%) patients removed their dentures overnight. MLRA indicated that potential risk factors for denture plaque were the duration of denture use (reference, ?0.5 years; 2.1–5 years: OR?=?4.155, P?=?0.001; >5 years: OR?=?7.238, P<0.001) and cleaning method (reference, chemical cleanser; running water: OR?=?7.081, P?=?0.010; brushing: OR?=?3.567, P?=?0.005). Potential risk factors for denture staining were female gender (OR?=?0.377, P?=?0.013), smoking (OR?=?5.471, P?=?0.031), tea consumption (OR?=?3.957, P?=?0.002), denture scratching (OR?=?4.557, P?=?0.036), duration of denture use (reference, ?0.5 years; 2.1–5 years: OR?=?7.899, P?=?0.001; >5 years: OR?=?27.226, P<0.001), and cleaning method (reference, chemical cleanser; running water: OR?=?29.184, P<0.001; brushing: OR?=?4.236, P?=?0.007). Conclusion Denture hygiene habits need further improvement. An understanding of the risk factors for denture plaque and staining may provide the basis for preventive efforts. PMID:24498369

  16. Adaptation of all-ceramic fixed partial dentures

    Microsoft Academic Search

    Márcia Borba; Paulo F. Cesar; Jason A. Griggs; Álvaro Della Bona

    2011-01-01

    ObjectivesTo measure the marginal and internal fit of three-unit fixed partial dentures (FPDs) using the micro-CT technique, testing the null hypothesis that there is no difference in the adaptation between the ceramic systems studied.

  17. Fracture Surface Analysis of Clinically Failed Fixed Partial Dentures

    Microsoft Academic Search

    B. Taskonak; J. J. Mecholsky; K. J. Anusavice

    2006-01-01

    Ceramic systems have limited long-term fracture resistance, especially when they are used in posterior areas or for fixed partial dentures. The objective of this study was to determine the site of crack initiation and the causes of fracture of clinically failed ceramic fixed partial dentures. Six Empress 2® lithia-disilicate (Li2O·2SiO2)-based veneered bridges and 7 experimental lithia-disilicate-based non-veneered ceramic bridges were

  18. Casting titanium partial denture frameworks: A radiographic evaluation

    Microsoft Academic Search

    Bert T. Cecconi; Raymond G. Koeppen; Rodney D. Phoenix; Mark L. Cecconi

    2002-01-01

    Statement of Problem. Titanium is the most biocompatible metal available for dental castings. However, there is some concern about the castability of titanium used on a daily basis. Purpose. A radiographic evaluation of titanium partial denture frameworks was undertaken to ascertain whether these castings were technically acceptable for clinical use. Material and Methods. Three hundred Grade II titanium removable partial

  19. Prefabricated light-polymerizing plastic pattern for partial denture framework.

    PubMed

    Takaichi, Atsushi; Wakabayashi, Noriyuki; Igarashi, Yoshimasa

    2011-10-01

    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. PMID:22346178

  20. Removable partial denture education in Portugal following the Bologna Process.

    PubMed

    Figueiral, M H; Fonseca, P; Campos, J C R; Correia, A R; Fernandes, M S; Branco, F J M

    2013-09-01

    The aim of this study was to investigate the current guidelines used for the undergraduate course subject Removable Partial Denture in Portuguese Dental Schools following the Bologna Process. All Dental Schools were sent a questionnaire, divided into the following areas: (I) organization and syllabus; (II) teaching methods; (III) materials and techniques; Answers about organization and syllabus of course subjects showed the most variability; teaching methods were identical regarding principal textbook and live demonstrations of laboratory/clinical procedures; the same techniques and materials are used in all the schools' dental clinics. The majority of Dental Schools present similar guidelines for removable partial dentures. PMID:24261105

  1. New telescopic crown design for removable partial dentures

    Microsoft Academic Search

    Shogo Minagi; Nobukuni Natsuaki; Goro Nishigawa; Takashi Sato

    1999-01-01

    Statement of problem. Special technical skills and experiences are required to fabricate a telescopic crown to provide adequate retention with precise frictional retention (“conus friction force”) between coping and telescope. It is also difficult to control clinically alterations of retentive forces after prolonged usage. Purpose. This study examined an innovative telescopic crown system for removable partial dentures that can be

  2. The use of implants as retainers for removable partial dentures.

    PubMed

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

    2010-01-01

    There has been little presented in the literature regarding the use of implant bodies as retainers for removable partial dentures. However, these fixtures can be a useful asset for restorative dentists, as they can be used when there is insufficient bone for a fixed prosthesis or as retainers for a provisional appliance until additional dental treatment is possible. PMID:21062705

  3. Biomechanical considerations on tooth-implant supported fixed partial dentures

    PubMed Central

    Calvani, Pasquale; Hirayama, Hiroshi

    2012-01-01

    This article discusses the connection of teeth to implants, in order to restore partial edentulism. The main problem arising from this connection is tooth intrusion, which can occur in up to 7.3% of the cases. The justification of this complication is being attempted through the perspective of biomechanics of the involved anatomical structures, that is, the periodontal ligament and the bone, as well as that of the teeth- and implant-supported fixed partial dentures. PMID:23255882

  4. Masticatory efficiency in complete denture wearers with reduced dental arches--a randomised cross-over study.

    PubMed

    Iegami, C M; Barbosa, W F; Furuyama, R J; Lima, J R B; de Campos, T T; Minagi, S; Tamaki, R

    2014-08-01

    One obstacle to placing artificial posterior teeth in manufacturing complete dentures is a reduction of the space between the maxilla and the mandible. Occasionally, second molar placement is not performed, as it does not affect aesthetics, phonetics or comfort. The aim of this study was to compare the masticatory efficiency between patients wearing maxillary and mandibular complete dentures with reduced dental arches (without second molars) (WSM) and with full dental arches (FDA). Twenty subjects were divided into two groups and randomly received new complete dentures. Patients in Group 1 were given dentures WSM, and those in Group 2 were given dentures with FDA. After the post-placement visits, an initial masticatory efficiency test was performed with Optocal, an artificial test food. Fifteen days later, second molars were placed in Group 1 and removed from Group 2, and a new test was performed. Comminuted material was treated and sieved under vibration. The mean and standard deviation of masticatory efficiency with FDA were 10.4 and 8.1, respectively. In the tests WSM, the mean and standard deviation were 8.4 and 3.3, respectively. After removing the second molars in Group 2 and adding them in Group 1, the mean and standard deviation were 15.7 and 14.7 for Group 1 and 12.5 and 10.4 for Group 2, respectively. Within the limitations of this study, placing artificial teeth up to the first molars can be performed when needed without compromising masticatory efficiency. PMID:24779746

  5. Dentures Basics

    MedlinePLUS

    ... They also can act as stable supports for bridges, overdentures or removable partial dentures. Your dentist will ... first developed to give people "artificial roots" for bridges or dentures in the lower jaw. The denture ...

  6. Chairside prefabricated fiber-reinforced resin composite fixed partial dentures.

    PubMed

    Meiers, J C; Freilich, M A

    2001-02-01

    The introduction of pre-impregnated fiber-reinforced resin composites has provided the dental profession with the opportunity to fabricate and deliver adhesive, esthetic, and metal-free tooth replacements. Utilizing this technology, a prefabricated fiber-reinforced resin composite fixed partial denture prototype that allows rapid, cost-effective, and noninvasive fixed tooth replacement for single anterior teeth has been developed. Ideal situations for this type of service include: a fixed replacement following tooth loss from trauma; a fixed tooth replacement in medically compromised patients who cannot sit for extended periods of time or have local anesthesia; periodontally compromised abutments; a fixed space maintainer following orthodontic movement; and a fixed provisional during the post implant healing phase prior to loading. This article describes the framework construction and placement protocol for the prefabricated fiber-reinforced resin composite fixed partial denture. PMID:12066682

  7. Stress distribution of abutments and base displacement with precision attachment- and telescopic crown-retained removable partial dentures.

    PubMed

    Saito, M; Miura, Y; Notani, K; Kawasaki, T

    2003-05-01

    Five types of removable partial dentures (two attachment dentures, two telescopic dentures and one clasp denture) were designed. The two attachment dentures were retained by the rigid-precision attachments with or without a stabilizing arm, and the two telescope dentures were retained with cone telescope crowns with or without cross-arch stabilization. The stresses acting on abutment teeth and denture bases and the movements of denture bases were investigated, and the influences of denture design were clarified. The stress acting on a terminal abutment tooth retained by a rigid-precision attachment or cone telescopic crown was larger than that acting on a terminal abutment tooth retained by a clasp. The attachment dentures tended to concentrate more stress at the terminal abutment tooth than did the telescopic dentures. The stress of denture base of an attachment denture and a telescopic denture was less than that of a clasp denture. There was no difference between the stresses of attachment and telescopic dentures. The displacement of the denture base tended to be less when the denture was designed with a rigid connection for the retainer and with cross-arch stabilization. PMID:12752927

  8. Prevalence of temporomandibular disorder signs in patients with complete versus partial dentures

    Microsoft Academic Search

    Osama A. Al-Jabrah; Yousef R. Al-Shumailan

    2006-01-01

    Objectives: To determine the prevalence of signs of a temporomandibular disorder (TMD) in completely edentulous patients wearing upper and lower complete dentures (CD) and to compare this to the prevalence of signs in partially edentulous patients wearing upper and lower clasp-retained acrylic removable partial dentures (RPD). Materials and methods: A questionnaire and a clinical examination were used to assess 200

  9. Direct and indirect fiber-reinforced fixed partial dentures: case reports.

    PubMed

    Ahlstrand, Wisua M; Finger, Werner J

    2002-05-01

    Direct and indirect fiber-reinforced resin composite fixed partial dentures are a new way to produce minimally invasive, esthetic, and cost-effective metal-free tooth replacements. These treatment alternatives have a number of indications, for example, chairside tooth replacements, long-term provisional fixed partial dentures, economically feasible tooth replacements for patients who cannot afford more traditional treatment regimens, and tooth replacements for medically compromised patients who are unable to withstand the physical stress associated with fabrication of traditional fixed prostheses. This article presents four typical cases in which fiber-reinforced fixed partial dentures seemed to be the preferable treatment modality. PMID:12014165

  10. Fiber-reinforced composites in fixed partial dentures

    PubMed Central

    Vallittu, Pekka

    2006-01-01

    Fiber-reinforced composite resin (FRC) prostheses offer the advantages of good aesthetics, minimal invasive treatment, and an ability to bond to the abutment teeth, thereby compensating for less-than-optimal abutment tooth retention and resistance form. These prostheses are composed of two types of composite materials: fiber composites to build the framework and hybrid or microfill particulate composites to create the external veneer surface. This review concentrates on the use of fiber reinforcement in the fabrication of laboratory or chairsidemade composite-fixed partial dentures of conventional preparation. Other applications of FRC in dentistry are briefly mentioned. The possibilities fiber reinforcement technology offers must be emphasized to the dental community. Rather than limiting discussion to whether FRC prostheses will replace metal-ceramic or full-ceramic prostheses, attention should be focused on the additional treatment options brought by the use of fibers. However, more clinical experience is needed. PMID:21526023

  11. Development of a device to study fatigue life of fixed partial dentures

    NASA Astrophysics Data System (ADS)

    Gutierrez, S. C.; Meseguer, M. D.; Estal, R.; Folguera, F.; Vidal, V.

    2012-04-01

    Fixed partial dentures can be fabricated by means of different materials and with different manufacturing processes. In order to establish possible differences among them, their behaviour, as fatigue life or cement shear bond strength, have to be evaluated. This article presents a modular, economic and robust device to evaluate fixed partial dentures and dental crowns. A base to support the fixed partial dentures and a device to simulate masticatory loads have been developed. The device has got a simple design. It is based on a pneumatic piston, with a pressure regulator to control masticatory loads. On a first stage, only vertical forces have been taking into account. However, the device will allow simulating tangential masticatory loads on the other axis, studying the behaviour of the fixed partial dentures submerged in a solution similar to saliva, changing masticatory load application, etc. with little modifications.

  12. Single tooth replacement using a ceramic resin bonded fixed partial denture: A case report

    PubMed Central

    Kara, Haluk Baris; Aykent, Filiz

    2012-01-01

    This article describes the use of an all ceramic resin-bonded fixed partial denture as a conservative solution for the replacement of an incisor. It is a minimally invasive technique that does not discolor the abutment teeth. PMID:22229014

  13. Telescopic crown-retained removable partial dentures: review and case report.

    PubMed

    Beschnidt, S M; Chitmongkolsuk, S; Prull, R

    2001-11-01

    Double crown-retained prostheses have been successfully used in partially edentulous patients. This type of retainer provides guidance, support, and protection from dislodging movement, and it transfers bite forces along the long axis of the abutment teeth. Furthermore, the denture can easily be retrieved when an abutment needs to be extracted. By modifying the preparation and veneering technique, overcontour of the double crowns can be minimized. Using custom-made all-ceramic crowns as prosthesis teeth and individualizing the denture base, esthetics can be improved. Longitudinal follow-up studies of 5 to 10 years report that conical crown-retained partial dentures have a lower failure rate compared to those retained with clasps or precision attachments. In a case report, clinical and technical aspects of constructing telescopic crown-retained removable partial dentures are discussed. PMID:11803658

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

    PubMed Central

    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

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

    PubMed

    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. PMID:25121066

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

    PubMed

    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. PMID:20101937

  17. Strength of zirconia fixed partial dentures: review of the literature

    PubMed Central

    GARGARI, M.; GLORIA, F.; CAPPELLO, A.; OTTRIA, L.

    2011-01-01

    SUMMARY Objective The aim of this study is a systematic review of the literature on the strength and long-term behavior of zirconia FPDs. Methods The literature search was performed using as the primary source the Medline database. Were also imposed a set of inclusion and exclusion criteria in order to narrow the search to differentiate the two distinct parts in which it was structured the review. In addition, MeSH terms were applied to further refine the choice of articles more relevant to the review. In the part of the review concerning the long-term behavior of zirconia fixed partial dentures were considered useful only those studies with a minimum follow-up of one year. Results The search provided a total of 813 articles, but only 25 were considered for the review because they were the only ones who satisfied search criteria. In particular, 13 items relate to the mechanical strength of zirconia prostheses and 12 regarding the long term behavior of zirconia FPDs. The resistance values also exceed the 2000 N while the survival rate reaches to almost 94%. Conclusions Based on this review, Zirconia FPDs can be considered reliable products in both the anterior and posterior fields with survival rates comparable to traditional metal-ceramic prostheses. PMID:23285392

  18. Technical failure rates of double crown-retained removable partial dentures

    Microsoft Academic Search

    M. Behr; E. Hofmann; M. Rosentritt; R. Lang; G. Handel

    2000-01-01

    Removable partial dentures (RPD) can be retained using conical crowns or parallel-sided telescopic double crowns. The purpose\\u000a of this study was to evaluate and compare the technical failure rate of the two retainer systems. One hundred seventeen dentures\\u000a made by dentists of the medical school were included. Seventy-four RPD were retained with parallel-sided crowns (n=251) and 43 with conical crowns

  19. 21 CFR 872.3600 - Partially fabricated denture kit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...b) Classification. Class II. The special controls for this device are FDA's: (1) “Use of International Standard ISO 10993 ‘Biological Evaluation of Medical Devices—Part I: Evaluation and Testing,’ ” and (2) “OTC Denture...

  20. Adaptation of all-ceramic fixed partial dentures

    PubMed Central

    Borba, Márcia; Cesar, Paulo F.; Griggs, Jason A.; Della Bona, Álvaro

    2011-01-01

    Objectives To measure the marginal and internal fit of three-unit fixed partial dentures (FPDs) using the micro-CT technique, testing the null hypothesis that there is no difference in the adaptation between the ceramic systems studied. Methods Stainless steel models of prepared abutments were fabricated to design the FPDs. Ten FPDs were produced from each framework ceramic (YZ - Vita In-Ceram YZ and IZ - Vita In-Ceram Zirconia) using CEREC inLab according to the manufacturer instructions. All FPDs were veneered using the recommended porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross-sections images. Five measuring locations were used as follows: MG – marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. The horizontal marginal discrepancy (HMD) was evaluated in another set of images. Results were statistically analyzed using ANOVA and Tukey tests (?=0.05). Results The mean values for MG, CA, AW, OA and HMD were significantly different for all tested groups (p<0.05). IZ exhibited greater mean values than YZ for all measuring locations except for AW and AOT. OA showed the greatest mean gap values for both ceramic systems. MG and AW mean gap values were low for both systems. Significance The ceramic systems evaluated showed different levels of marginal and internal fit, rejecting the study hypothesis. Yet, both ceramic systems showed clinically acceptable marginal and internal fit. PMID:21920595

  1. Fabrication of an all-ceramic abutment crown under an existing removable partial denture using CAD/CAM technology.

    PubMed

    Marchack, Baldwin W; Chen, Linda B; Marchack, Christopher B; Futatsuki, Yukiko

    2007-12-01

    Fabricating a crown beneath an existing removable partial denture is technique sensitive, difficult, and time consuming. A procedure is described using CAD/CAM technology to fabricate an all-ceramic crown under an existing removable partial denture that is simple, esthetic, and convenient for the patient and the clinician. PMID:18061742

  2. Removal of a metal-ceramic fixed partial denture with a loose retainer.

    PubMed

    Verrett, Ronald G; Mansueto, Michael A

    2003-03-01

    In clinical practice, it is necessary to remove a ceramic-veneered fixed partial denture when an abutment becomes loose. When possible, the fixed partial denture is removed in a single piece, allowing recementation when appropriate. A 1-piece removal is challenging, often putting the veneer and abutment teeth at risk for damage. This article describes a technique for fabricating and using a 2-piece matrix that both protects the prosthesis and better directs removal forces along the long axis of the abutments. PMID:12677606

  3. All-cast-titanium removable partial denture for a patient with a severely reduced interarch distance: a case report.

    PubMed

    Wakabayashi, N; Mizutani, H; Ai, M

    1997-03-01

    A patient had a maxillary posterior edentulous area and severely reduced interarch distance that precluded the use of a conventional removable partial denture. An all-cast-titanium denture base and occlusal surface was designed to fabricate a removable denture to restore the edentulous area. Titanium was cast in a centrifugal casting machine with electric are melting design. The desirable characteristics of titanium, such as favorable mechanical properties, low density, and comparatively low cost, make this metal particularly effective and suitable for construction of an all-cast-metal denture base with a metal occlusal surface. PMID:9452683

  4. Long-term analysis of telescopic crown retained removable partial dentures: Survival and need for maintenance

    Microsoft Academic Search

    Bernd Wöstmann; Markus Balkenhol; Andrea Weber; Paul Ferger; Peter Rehmann

    2007-01-01

    ObjectivesThe aim of this retrospective longitudinal study was to evaluate the clinical long-term survival of telescopic crown retained removable partial dentures (TRPDs), the influencing factors on survival as well as the type and number of necessary treatments during the observation time.

  5. Viscoelastic finite element analysis of an all-ceramic fixed partial denture

    Microsoft Academic Search

    Paul H. DeHoff; Kenneth J. Anusavice; Nils Götzen

    2006-01-01

    In recent years metal-free ceramic systems have become increasingly popular in dental practice because of their superior aesthetics, chemical durability and biocompatibility. Recently, manufacturers have proposed new dental ceramic systems that are advertized as being suitable for posterior fixed partial dentures (FPDs). Reports indicate that some of these systems have exhibited poor clinical performance. The objective of this study was

  6. Comparative study of circumferential clasp retention force for titanium and cobalt-chromium removable partial dentures

    Microsoft Academic Search

    Renata Cristina Silveira Rodrigues; Ricardo Faria Ribeiro; Maria da Gloria Chiarello de Mattos; Osvaldo Luiz Bezzon

    2002-01-01

    Statement of Problem. The interest in using titanium to fabricate removable partial denture (RPD) frameworks has increased, but there are few studies to support its use. Purpose. The objective of this study was to compare circumferential RPD clasps made of commercially pure titanium and identical clasps made of 2 different cobalt (Co)-chromium (Cr) alloys by testing insertion\\/removal and radiographically inspecting

  7. Comparison of titanium and cobalt-chromium removable partial denture clasps

    Microsoft Academic Search

    Jay T. Bridgeman; Victoria A. Marker; Susan K. Hummel; Byron W. Benson; Larry L. Pace

    1997-01-01

    Statement of problem. The use of titanium alloys for removable partial dentures is an increasingly popular application. While the flexibility of titanium would allow for cast clasps to be placed in deeper undercuts than advisable with cobalt-chromium, it is possible that the retentive forces of the titanium clasp might not maintain sufficient retention after repeated flexing of the clasp arm

  8. Why do dentists struggle with removable partial denture design? An assessment of financial and educational issues

    Microsoft Academic Search

    P F Allen; C D Lynch

    2006-01-01

    Aim Published studies in the international dental literature illustrate that the quality of prescription and fabrication of cobalt-chromium removable partial dentures (CCRPDs) by general dental practitioners frequently fail to comply with ethical and legal requirements. The reasons cited for this in the past have broadly related to either financial or educational issues. The aim of this investigation is to determine

  9. Name: McNamara Question: In patients needing a removable partial denture, do double crown supported RPDs have the same

    E-print Network

    Goldman, Steven A.

    , intervention, comparison, outcome) P: missing teeth I: telescopic or double crowns with RPD C dentures AND ("telescopic" OR "double") AND crowns Summary of Findings Author Study Design AppraisalName: McNamara Question: In patients needing a removable partial denture, do double crown

  10. Technical failure rates of double crown-retained removable partial dentures.

    PubMed

    Behr, M; Hofmann, E; Rosentritt, M; Lang, R; Handel, G

    2000-06-01

    Removable partial dentures (RPD) can be retained using conical crowns or parallel-sided telescopic double crowns. The purpose of this study was to evaluate and compare the technical failure rate of the two retainer systems. One hundred seventeen dentures made by dentists of the medical school were included. Seventy-four RPD were retained with parallel-sided crowns (n = 251) and 43 with conical crowns (n = 160). Following the medical report follow-ups from January 1992 to December 1998, technical RPD failures were noted and analyzed. Technical problems occurred during the observation time in 48.8% of the conical retained dentures and 34.2% of the parallel-sided retained dentures. In both cases, loss of cementation was most frequently noted, while loss of the facings occurred only with conical crowns. Other technical failures did not depend on the type of retainer system used. These were most frequently problems with the denture base, e.g., fracture of artificial teeth or the metal framework. We conclude that there were different technical failures of both double crown retainer systems. These problems were not insignificant in number but treatable. PMID:11218506

  11. Immediate replacement removable partial dentures with cobalt-chromium frameworks: rationale, technology and a case report.

    PubMed

    Hassan, L; Juszczyk, A S; Clark, R K F

    2005-10-01

    The advantages of removable partial dentures with cobalt-chromium frameworks over those made entirely of acrylic resin, in oral health and hygiene, are well documented. However, in cases where teeth are to be extracted for fitting the removable partial denture, a difficulty arises because of the need to test the fit of the removable partial denture framework. The advent of two modern technologies-- laser welding and metal bonding agents -- make it possible to test the fit of the major part of the framework prior to adding additional metal components to support artificial teeth. A case is described in which the four lower incisors were extracted. The main part of the framework was constructed and its fit tested. A second casting was laser-welded to the lingual plate of the first casting to support the artificial incisor teeth. This technique avoids the need to make an acrylic resin temporary denture but incurs the cost of the additional technical work and so the advantages may be considered to be economically neutral. PMID:16159357

  12. Effect of connector width on stress distribution in all ceramic fixed partial dentures (A 3D finite element study)

    Microsoft Academic Search

    Sepideh Mokhtarikhoee; Alireza Jannesari; Hamid Behroozi; Saeedeh Mokhtarikhoee

    2008-01-01

    Statement of problem: Connectors in fixed partial dentures (FPDs) are the weakest areas and responsible for failure in most cases. Optimizing the design of connectors will lead to higher strength and better performance of all-ceramic FPDs.

  13. Cyclic mechanical pressure-loading alters epithelial homeostasis in a three-dimensional in vitro oral mucosa model: clinical implications for denture-wearers.

    PubMed

    Shiomi, A; Izumi, K; Uenoyama, A; Saito, T; Saito, N; Ohnuki, H; Kato, H; Kanatani, M; Nomura, S; Egusa, H; Maeda, T

    2015-03-01

    Denture-wearing affects the quality and quantity of epithelial cells in the underlying healthy oral mucosa. The physiologic mechanisms, however, are poorly understood. This study aimed to compare histologic changes and cellular responses of an epithelial cell layer to cyclic mechanical pressure-loading mimicking denture-wearing using an organotypic culture system to develop a three-dimensional in vitro oral mucosa model (3DOMM). Primary human oral keratinocytes and fibroblasts were serially grown in a monolayer culture, and cell viability was measured under continuous cyclic mechanical pressure (50 kPa) for 7 days (cycles of 60 min on, 20 s off to degas and inject air). Upon initiation of an air-liquid interface culture for epithelial stratification, the cyclic pressure, set to the mode above mentioned, was applied to the 3DOMMs for 7 days. Paraffin-embedded 3DOMMs were examined histologically and immunohistochemically. In the monolayer culture, the pressure did not affect the viability of oral keratinocytes or fibroblasts. Few histologic changes were observed in the epithelial layer of the control and pressure-loaded 3DOMMs. Immunohistochemical examination, however, revealed a significant decrease in Ki-67 labelling and an increase in filaggrin and involucrin expression in the suprabasal layer of the pressure-loaded 3DOMMs. Pressure-loading attenuated integrin ?1 expression and increased matrix metalloproteinase-9 activity. Incomplete deposition of laminin and type IV collagen beneath the basal cells was observed only in the pressure-loaded 3DOMM. Cyclic pressure-loading appeared to disrupt multiple functions of the basal cells in the 3DOMM, resulting in a predisposition towards terminal differentiation. Thus, denture-wearing could compromise oral epithelial homeostasis. PMID:25472623

  14. Dental impact on daily living of telescopic crown-retained partial dentures.

    PubMed

    Wöstmann, Bernd; Balkenhol, Markus; Kothe, Andrea; Ferger, Paul

    2008-01-01

    This study aimed to analyze changes in Dental Impact on Daily Living (DIDL) scores in patients who had no prosthesis, a nonfunctioning prosthesis, or an acrylic resin prosthesis after providing them with a telescopic crown-retained partial denture. DIDL scores were recorded in 98 patients prior to and 6 to 24 months after treatment. All DIDL scores (overall and dimension scores) increased significantly after treatment. Results were only slightly affected by gender and age. Patients with fewer teeth benefited more than those with more teeth. Within the limitations of this study, the results show that a telescopic crown-retained partial denture can improve patients' oral health-related quality of life. PMID:18950064

  15. Fracture characteristics of anterior resin-bonded zirconia-fixed partial dentures

    Microsoft Academic Search

    Martin Rosentritt; Stefan Ries; Carola Kolbeck; Maria Westphal; Ernst-Jürgen Richter; Gerhard Handel

    2009-01-01

    Resin-bonded fixed partial dentures (RBFPD) are used as a minimal invasive, tooth-preventing alternative for replacing anterior\\u000a teeth. Zirconia cantilever restorations were supposed to show sufficient strength for a clinical application. The aim of this\\u000a investigation was to determine the fracture characteristics of cantilever and two-retainer RBFPD, which are fabricated by\\u000a computer-manufactured high-strength zirconia. Human incisors and canines were used to

  16. Marginal adaptation of three-unit fixed partial dentures constructed from pressed ceramic systems

    Microsoft Academic Search

    M Dai; S Chitmongkolsuk; T Gerds; J R Strub; C F J Stappert

    2004-01-01

    Purpose This study compares the marginal accuracy of posterior metal ceramic (MC), all-ceramic IPS Empress®2 and experimental pressed ceramic (EPC-VP 1989\\/4) three-unit fixed partial dentures (FPD), before and after luting and after thermo-mechanical fatigue in a dual-axis chewing simulator.Materials and methods Caries-free human teeth (n=160) were used as abutments for the fabrication of eighty posterior three-unit FPD, divided into two

  17. Failure ofAll-ceramic Fixed Partial Dentures invitro andinvivo: Analysis andModeling

    Microsoft Academic Search

    J. A. Teskl; A. Sorensen

    Hertzian conecracks visible attheloading site of20all- ceramic fixed partial dentures (FPDs), tested invitro, ledtothe hypotheses that failure wasduetothepropagation oflocalized contact damage crack systems (Hertzian stress state) andthat such damage wasanunlikely clinical failure mode. Fractographic analysis ofthe20laboratory-faile d andnineclinically-faile d all- ceramic FPDsallowed fordefinitive testing ofthese hypotheses andacomparison between invitro andinvivo failure behavior. In all cases, failure occurred intheFPDconnectors (none from

  18. Failure of All-ceramic Fixed Partial Dentures in vitro and in vivo: Analysis and Modeling

    Microsoft Academic Search

    J. R. Kelly; J. A. Tesk; J. A. Sorensen

    1995-01-01

    Hertzian cone cracks visible at the loading site of 20 all-ceramic fixed partial dentures (FPDs), tested in vitro, led to the hypotheses that failure was due to the propagation of localized contact damage crack systems (Hertzian stress state) and that such damage was an unlikely clinical failure mode. Fractographic analysis of the 20 laboratory-failed and nine clinically-failed all-ceramic FPDs allowed

  19. Survey of Impression Materials and Techniques in Fixed Partial Dentures among the Practitioners in India

    PubMed Central

    Moldi, Arvind; Puranik, Shivakumar; Karan, Smita; Deshpande, Sumit; Neela, Neelima

    2013-01-01

    Objective. Anecdotal evidence suggests that impression materials and techniques used in general dental practice for fixed partial dentures vary from those taught in dental schools. The aim of this survey was to integrate impression techniques evolved all over the years for fixed partial dentures and to know the techniques and materials which are used in the present day by the practitioners. Materials and Methods. A total of 1000 questionnaires were sent to various practitioners in India, out of which 807 questionnaires were filled. Results. The results showed that 84.8% of prosthodontists (65.56%, urban areas) use elastomeric impression materials as well as irreversible hydrocolloids and 15.2% use irreversible hydrocolloid only. Amongst other practitioners, 55.46% use irreversible hydrocolloid (45%, rural and semiurban areas) and 44.54% use elastomeric impression materials. Elastomeric impression technique practiced most commonly is putty reline with/without spacer (77.2%); other techniques are multiple-mix and monophase techniques. Conclusion. The ideal materials, technique, and armamentarium are required for the long-term success of the treatment for fixed partial denture. Also, if the ideal procedure is not followed, it will lead to a compromised fit of the final prosthesis and failure of the treatment. PMID:23691334

  20. Implant-assisted removable partial dentures as an alternative treatment for partial edentulism: a review of the literature.

    PubMed

    Chatzivasileiou, Konstantinos; Kotsiomiti, Eleni; Emmanouil, Ioannis

    2015-01-01

    This study reviewed the current literature concerning implant-assisted removable partial dentures (RPDs) in order to present the existing knowledge about performance issues. An electronic search was conducted on the PubMed database for published English-language articles that contained information about implant-assisted RPDs. A review of these articles indicated that the combination of dental implants with RPDs constitutes a cost-efficient prosthetic protocol that can offer solutions to problematic aspects of treatment with removable partial dentures. Well-designed studies are still needed to provide robust evidence on critical issues, such as design guidelines, long-term survival of implants associated with RPDs, and their effect on patients' quality of life. PMID:25734282

  1. A preliminary report of designing removable partial denture frameworks using a specifically developed software package.

    PubMed

    Han, Jing; Wang, Yong; Lü, Peijun

    2010-01-01

    This article reports on a method to digitally survey and build virtual patterns for removable partial denture (RPD) frameworks using a new three-dimensional (3D) computer-aided design/computer-assisted manufacturing (CAD/CAM) software package developed specifically for RPD design. The procedure included obtaining 3D data from partially dentate casts, deciding on the path of insertion, and modeling the shape of the components of the frameworks digitally. The completed model data were stored as stereolithography (STL) files, which are commonly used in transferring CAD/CAM models to rapid prototyping technologies. Finally, metal RPD frameworks were fabricated using a selective laser melting technique. PMID:20617229

  2. Internal porosity of cast titanium removable partial dentures: Influence of sprue direction on porosity in circumferential clasps of a clinical framework design

    Microsoft Academic Search

    Ioana Baltag; Kouichi Watanabe; Haruka Kusakari; Osamu Miyakawa

    2002-01-01

    Statement of Problem. Although internal porosity is a potential risk factor for clasp fracture, little is known about its frequency in the clasps of titanium removable partial dentures. Purpose. This study investigated the influence of the direction of auxiliary sprues on porosity in the circumferential clasps of a pressure-cast titanium removable partial denture. Material and Methods. Wax patterns of a

  3. Investigation of the effect of three sprue designs on the porosity and the completeness of titanium cast removable partial denture frameworks

    Microsoft Academic Search

    Hamda S. Al-Mesmar; Steven M. Morgano; Leonard E. Mark

    1999-01-01

    Statement Of Problem. Although titanium has been used to cast removable partial denture frameworks, the casting process is arduous and requires specialized equipment. Purpose. This study evaluated the ability of 3 sprue designs (tree, ball, and circular) to produce complete, void-free castings of removable partial denture frameworks made from commercially pure titanium. Methods And Material. A cast with a Kennedy

  4. [Three-dimensional displacement of implant-supported cantilever fixed partial denture under oblique loading].

    PubMed

    Wang, Hongren; Li, Aijie; Chen, Xinmin

    2013-06-01

    The purpose of this study was to research the three-dimensional displacements of implant-supported cantilever fixed partial denture (CFPD) under oblique loading. One Beagle dog was used in this experiment. Two immediate implants of ITI were inserted in the mandible of the dog, and the implant-supported CFPD which used the implants as abutments was made in vitro fresh mandible. Then the digital laser speckle technique was employed to measure the three-dimensional displacements of CFPD under different oblique loading. We found that when an oblique loading was exerted on the pontic, the displacement increased with increasing of load. Under equal loading, the displacement of the abutment near to the pontic was smaller than that of the pontic but greater than that of the abut-ment far from the pontic. When oblique loading was exerted on the abutment, the displacement of the direct loaded abutment was greater than that of the other abutment and the pontic. Under the.eeual loading, the displacement of implant-supported CFPD of loading on pontic was greater than that of loading on abutments. The experiments demonstrated that implant-supported cantilever fixed partial denture (CFPD) is an effective and advisable therapy for totally? or partially edentulous patients. However, it is also suggested that the clinicians should avoid exerting oblique loading, especially the obliqe loading of the pontic when th e CPDF is used. PMID:23865315

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

    PubMed

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

    2004-05-01

    Mismatch occurring during the fabrication of implant-supported dentures may induce stress to the peri-implant bone. The purpose of this study was to investigate the influence of two different alloys and the fabrication method on the marginal accuracy of cast partial dentures. Two laboratory implants were bonded into an aluminium block so that the distance between their longitudinal axes was 21 mm. Frameworks designed for screw-retained partial dentures were cast either with pure titanium (rematitan) or with a CoCr-alloy (remanium CD). Two groups of 10 frameworks were cast in a single piece. The first group was made of pure titanium, and the second group of a CoCr-alloy (remanium CD). A third group of 10 was cast in two pieces and then laser-welded onto a soldering model. This latter group was also made of the CoCr-alloy. All the frameworks were screwed to the original model with defined torque. Using light microscopy, marginal accuracy was determined by measuring vertical gaps at eight defined points around each implant. Titanium frameworks cast in a single piece demonstrated mean vertical gaps of 40 microm (s.d. = 11 microm) compared with 72 microm (s.d. = 40 microm) for CoCr-frameworks. These differences were not significant (U-test, P = 0.124) because of a considerable variation of the values for CoCr-frameworks (minimum: 8 microm and maximum: 216 microm). However, frameworks cast in two pieces and mated with a laser showed significantly better accuracy in comparison with the other experimental groups (mean: 17 microm +/- 6; P < 0.01). (i) The fit of implant-supported partial dentures cast with pure titanium in a single piece is preferable to that of those made with the CoCr-alloy and (ii) the highest accuracy can be achieved by using a two-piece casting technique combined with laser welding. Manufacturing the framework pieces separately and then welding them together provides the best marginal fit. PMID:15140174

  6. Radiographic and metallographic evaluation of porosity defects and grain structure of cast chromium cobalt removable partial dentures.

    PubMed

    Dharmar, S; Rathnasamy, R J; Swaminathan, T N

    1993-04-01

    A study was undertaken to determine the defects in the internal microstructure of clasps of cast chromium cobalt removable partial denture frameworks. Ninety cast frameworks were radiographically evaluated for porosity with an industrial radiographic machine. The grain structure of the clasps was analyzed with an optical photomicroscope before and after various heat treatments. The radiographic study showed a large number of internal defects in various parts of removable partial denture frameworks. The grain structure study revealed microporosities randomly distributed within the matrix. Various heat treatments were performed and resulted in no change in the grain structure of the original castings. PMID:8463964

  7. Use of an alternative pontic foundation technique for a fiber-reinforced composite fixed partial denture: a clinical report.

    PubMed

    Ayna, Emrah; Celenk, Sema

    2005-05-01

    This article describes the treatment of a patient for whom a fiber-composite laminate dowel and core and polyethylene fiber were used as a conservative alternative to provide a dowel-and-core and fixed partial denture foundation. The treatment plan included removing the existing restoration on the maxillary right first molar, placing a fiber-reinforced resin dowel and core for retention and reinforcement of the maxillary first premolar, and fabricating a definitive restoration using polyethylene fiber to reinforce the fixed partial denture. PMID:15867748

  8. Strain Distribution in a Kennedy Class I Implant Assisted Removable Partial Denture under Various Loading Conditions

    PubMed Central

    Shahmiri, Reza; Aarts, John M.; Bennani, Vincent; Swain, Michael V.

    2013-01-01

    Purpose. This in vitro study investigates how unilateral and bilateral occlusal loads are transferred to an implant assisted removable partial denture (IARPD). Materials and Methods. A duplicate model of a Kennedy class I edentulous mandibular arch was made and then a conventional removable partial denture (RPD) fabricated. Two Straumann implants were placed in the second molar region, and the prosthesis was modified to accommodate implant retained ball attachments. Strain gages were incorporated into the fitting surface of both the framework and acrylic to measure microstrain (?Strain). The IARPD was loaded to 120Ns unilaterally and bilaterally in three different loading positions. Statistical analysis was carried out using SPSS version 18.0 (SPSS, Inc., Chicago, IL, USA) with an alpha level of 0.05 to compare the maximum ?Strain values of the different loading conditions. Results. During unilateral and bilateral loading the maximum ?Strain was predominantly observed in a buccal direction. As the load was moved anteriorly the ?Strain increased in the mesial area. Unilateral loading resulted in a twisting of the structure and generated a strain mismatch between the metal and acrylic surfaces. Conclusions. Unilateral loading created lateral and vertical displacement of the IARPD. The curvature of the dental arch resulted in a twisting action which intensified as the unilateral load was moved anteriorly. PMID:23737788

  9. Decision-making for treatment planning a cantilevered fixed partial denture.

    PubMed

    Hill, Edward E

    2009-01-01

    Considerable controversy exists in the dental literature regarding cantilevered pontics. This article discusses basic concepts of the cantilever fixed partial denture (CFPD) in which one cantilevered pontic is supported by only one or two abutment teeth. Three primary factors should be considered carefully to optimize the prognosis for a CFPD: abutment selection, control of functional forces, and rigidity/strength of connectors. Abutments should have a root surface area greater than the tooth being replaced and a crown-to-root ratio of 2:3. They also should exhibit minimal mobility and be vital and periodontally sound. Contact on cantilevered pontics should be light in centric position and nonexistent in excursions. CFPDs ideally should be metal or metal-ceramic, and connectors, which are high-stress areas, require bulk for strength. A cantilevered prosthesis may require more consideration and planning than a conventional fixed partial denture, but when kept within the patient's biological limitations and executed properly, can provide a restorative option with many advantages. PMID:19998725

  10. Effect of framework design on fracture resistance of zirconium oxide posterior fixed partial dentures

    PubMed Central

    Salimi, Hadi; Mosharraf, Ramin; Savabi, Omid

    2012-01-01

    Introduction: The effect of framework design modifications in all-ceramic systems is not fully understood. The aim of this investigation was to evaluate the effect of different framework designs on fracture resistance of zirconium oxide posterior fixed partial dentures (FPD). Materials and Methods: Thirty two posterior zirconia FPD cores were manufactured to replace a second premolar. The specimens were divided into four groups; I: 3 × 3 connector and standard design, II: 3 × 3 connector and modified design, III: 4 × 4 connector dimension, and standard design and IV: 4 × 4 connector dimension and modified design. After storing for one week in artificial saliva and thermocycling (2000 cycles, 5-55°C), the specimens were loaded in a universal testing machine at a constant cross-head speed of 0.5 mm/min until failure occurred. The Weibull, Kruskal-Wallis, and Mann-Whitney tests were used for statistical analysis (? = 0.05). Results: The mean fracture resistance of groups with 4 × 4 mm connector was significantly higher than groups with 3 × 3 mm connector (P < 0.001). Although, the fracture resistance of the modified frameworks was increased in the present study (1.1 times), they were not significantly different from anatomic specimens (P = 0.327). Conclusions: The fracture resistance of the zirconia posterior-fixed partial dentures was significantly affected by the connector size; it was not affected by the framework modification. PMID:23559956

  11. Single tooth replacement using a modified metal-ceramic resin-bonded fixed partial denture: a clinical report

    Microsoft Academic Search

    Yoshiyuki Hagiwara; Hideo Matsumura; Seiji Tanaka; Julian B. Woelfel

    2004-01-01

    This article describes the use of a modified metal-ceramic resin-bonded fixed partial denture (MMC RBFPD) as a conservative solution for the replacement of an incisor. It is a minimally invasive technique which does not discolor the abutment teeth.

  12. Provisional repair of a zirconia fixed partial denture with fibre-reinforced restorative composite: a clinical report.

    PubMed

    Bagis, Bora; Ustaomer, Sedanur; Lassila, Lippo V J; Vallittu, Pekka K

    2009-03-01

    Although all-ceramic restorations have become popular, they present some biomechanical problems. Some technical failures can be repaired intraorally to help maintain the longevity of the restoration. This clinical report describes an intraoral method for repairing a fractured 4-unit posterior zirconia-based ceramic fixed partial denture using fibre-reinforced composite material. PMID:19267965

  13. The teaching of fixed partial dentures in undergraduate dental schools in Ireland and the United Kingdom.

    PubMed

    Lynch, C D; Singhrao, H; Addy, L D; Gilmour, A S M

    2010-12-01

    All areas of the practice of dentistry are evolving at a considerable pace. One area in particular which has seen a rapid revolution is the oral rehabilitation of partially dentate adults. The aim of this study was to describe the contemporary teaching of fixed partial dentures (FPDs) in dental schools in Ireland and the United Kingdom. An online questionnaire which sought information in relation to the current teaching of FPDs was developed and distributed to 15 Irish and UK dental schools with undergraduate teaching programmes in Spring 2009. Responses were received from 12 schools (response rate=80%). All schools offer teaching programmes in relation to FPDs. The number of hours devoted to pre-clinical/phantom head teaching of FPDs ranged from 3 to 42h (mean: 16h). The staff/student ratio for pre-clinical teaching courses in FPDs ranged from 1:6 to 1:18 (mode: 1:12). Cantilever resin-retained FPDs were the most popular type of FPD provided clinically (average=0·83 per school; range=1-2). Five schools (42%) report that they have requirements (e.g. targets, quotas, competencies) which students must complete prior to graduation in relation to FPDs. Fixed partial dentures form an important part of the undergraduate teaching programme in UK and Irish dental schools. While this teaching is subjected to contemporary pressures such as lack of curriculum time and a lack of available clinical facilities and teachers, there is evidence that teaching programmes in this area are evolving and are sensitive to current clinical practice trends and evidence-based practice. PMID:20500547

  14. Aesthetic Rehabilitation of Oligodontia in Primary Dentition with Adhesive Partial Denture

    PubMed Central

    Correia, Marília Ferreira; Nogueira, Marianne Nicole; Bedran, Telma Blanca; Palomari Spolidorio, Denise Madalena

    2013-01-01

    The primary teeth are essential for bone development and establishment of the arches on occlusion. Thus, the congenitally absence of teeth may trigger a shift in the balance of the occlusion, promoting disharmony in the structures of the maxilla-mandibular system. However, some interventions are possible to be performed in these cases even in pediatric patients, to redirect growth, preventing growth deviations and reestablishing the aesthetic. The aim of this paper is to report the treatment of a 4-year-old child presenting congenitally absence of mandibular central and lateral incisors and maxilla lateral incisors, which consequently compromises aesthetics, occlusal function, and the development and the functional growth of the bones. The oral rehabilitation was performed with an adhesive partial denture, which was able to restore the aesthetic and the occlusal function, therefore being a viable alternative in the treatment of this patient of little age. PMID:24319602

  15. Survival of abutment teeth used for telescopic abutment retainers in removable partial dentures.

    PubMed

    Dittmann, Britta; Rammelsberg, Peter

    2008-01-01

    This retrospective clinical study investigated the survival of 385 abutment teeth retaining 117 removable partial dentures with 3 types of telescopic abutment retainers. Within a mean service time of 6.26 years, 8.8% of 385 abutment teeth were extracted. Cox regression analysis revealed a significantly higher risk of tooth loss for posterior teeth (odds ratio: 2.985) and for teeth with root canal treatment (odds ratio: 3.298), whereas age, sex, and number and type of telescopic retainer had no influence on survival. Root canal-treated teeth did not show a higher fracture rate, excluding this as an explanation for an increased risk of tooth loss. PMID:18717090

  16. Intraoral Repair of All Ceramic Fixed Partial Denture Utilizing Preimpregnated Fiber Reinforced Composite

    PubMed Central

    Turkaslan, Süha; Tezvergil-Mutluay, Arzu

    2008-01-01

    All ceramic fixed partial dentures (FPD)s exhibit enhanced biocompatibility and esthetics as compared to metal-ceramic restorations. However, framework fractures are frequently reported especially when the connector dimensions are inadequate to withstand the high tensile stresses. The repair of the failed connector would be desirable rather than the complete removal and renewal since the latter is an expensive and time consuming procedure. Furthermore, the replacement or removal of the restoration for extra-oral repair purposes might increase the risk of destroying the entire restoration or damaging the abutment teeth during the removal. This article presents a direct intra-oral method that may be used to repair the connector fractures of all-ceramic FPDs which are otherwise clinically satisfactory. In the present technique, the connector is reconstructed intraorally utilizing composite resin restorative material reinforced with E-glass-fiber. PMID:19212511

  17. Biomechanical Response in Mandibular Bone due to Mastication Loading on 3-Unit Fixed Partial Dentures

    PubMed Central

    Field, Clarice; Li, Qing; Li, Wei; Swain, Michael

    2010-01-01

    An understanding of functional responses in oral bone is a crucial component of dental biomechanics. The purpose of this study was to investigate the potential biological remodelling response during mastication on the mandibular pre- and post-insertion of a fixed partial denture (FPD). A series of three-dimensional (3D) finite element analysis (FEA) models were presented pre- and postextraction to determine the biomechanical responses to masticatory loading in the anterior mandible. Equivalent strains were analysed at lingual/buccal and mesial/distal areas of the premolar to molar region and quantified to anticipate bone remodelling response. Mandibular bone incorporating an FPD experienced substantially greater stress/strain magnitudes than that prior to placement of fixed prosthodontics, which is suggestive of engagements of bone remodelling. The results suggest similar outcomes to those reported clinically. Developing a simulation reflecting the outcomes of restorative treatment can provide meaningful insight into restorative treatment planning, clinical outcomes, and fixed prosthodontics designs. PMID:20981154

  18. Single Tooth Replacement Using InCeram Resin Bonded Fixed Partial Denture: A Clinical Report

    PubMed Central

    Moslehifard, Elnaz; Farid, Farzaneh

    2014-01-01

    This clinical report describes a treatment option for replacement of a missing mandibular anterior tooth using InCeram resin bonded fixed partial denture (RBFPD). The conventional approach for replacing mandibular incisors dictates the placement of either a conventional porcelain-fused-to-metal (PFM) bridge, Maryland bridge, or fiber-reinforced composite veneer bridge and several appearance-related disadvantages have been reported in the use of a prosthesis that incorporates a metal substructure. The InCeram bridge is a minimally invasive restoration and eliminates undesirable incisal graying frequently observed in metal RBFPDs. This method was successfully clinically applied to overcome shortcomings of other approaches that may require a minimal invasive technique to preserve lasting sound tooth structure. PMID:24910683

  19. An implant-supported removable partial denture for a patient with post-inflammatory scar contracture caused by burn complications: a clinical report

    PubMed Central

    Kim, Jee-Hwan

    2012-01-01

    The scars and contracture around the oral-facial region may cause difficulty in prosthodontic treatment to restore esthetics and function for the patients, who suffered severe burns. This article presents a technique that uses a fixed partial denture prepared with a conventional milling technique and an attachment to support anterior cantilever removable partial denture, thereby providing a more esthetically acceptable and functional result. PMID:22439102

  20. Veneering technique for a Ti-6Al-7Nb framework used in a resin-bonded fixed partial denture with a highly filled indirect composite.

    PubMed

    Matsumura, Hideo; Yoneyama, Takayuki; Shimoe, Saiji

    2002-12-01

    This article presents a veneering technique for fixed partial denture frameworks made from a Ti-6Al-7Nb alloy. The fixed partial denture framework was prepared with a magnesia-based mold material and a centrifugal casting machine. An esthetic veneer was fabricated with a highly filled dual-polymerized composite material and a metal-conditioning agent. This technique can be applied as a standardized veneering procedure for the titanium alloy, for which porcelain fusing is currently difficult. PMID:12488858

  1. A comparative study of the centrifugal and vacuum-pressure techniques of casting removable partial denture frameworks.

    PubMed

    Shanley, J J; Ancowitz, S J; Fenster, R K; Pelleu, G B

    1981-01-01

    A study was undertaken to evaluate two techniques for casting accuracy on removable partial denture frameworks: centrifugal casting and vacuum-pressure casting. A standard metal die with predetermined reference points in a horizontal plane was duplicated in refractory investment. The casts were waxed, and castings of nickel-chrome alloy were fabricated by the two techniques. Both the casts and the castings were measured between the reference points with a measuring microscope. With both casting methods, the differences between the casts and the castings were significant, but no significant differences were found between castings produced by the two techniques. Vertical measurements at three designated points also showed no significant differences between the castings. Our findings indicate that dental laboratories should be able to use the vacuum-pressure method of casting removable partial denture frameworks and achieve accuracy similar to that obtained by the centrifugal method of casting. PMID:7007622

  2. Short-term retrospective case series of implant-assisted removable partial dentures with locator abutments.

    PubMed

    Ortiz-Puigpelat, Octavi; Gargallo-Albiol, Jordi; Hernández-Alfaro, Federico; Cabratosa-Termes, Josep

    2014-01-01

    The purpose of this retrospective case series was to report on the clinical performance of implant-assisted removable partial dentures (IARPDs) with Locator abutments in different partial edentulism situations, with a mean follow-up period of 28.6 months. Twelve consecutive patients were treated with IARPDs. A total of 24 implants were placed in the edentulous area. Minimum follow-up period was 12 months. Overall patient satisfaction, health of peri-implant tissues, survival of implants and abutments, and prosthetic complications were reported. Overall implant survival was 91.6%; two implants failed. No major complications were reported-only one IARPD metal framework broke. No Locator abutment loosening was reported. Within the limitations of this retrospective study, treatment with IARPDs can improve the patient's function, phonetics, and esthetics without the need for extensive bone regeneration surgeries and prosthodontic rehabilitations. However, well-designed prospective clinical studies on IARPDs are needed to support their long-term use. PMID:25411746

  3. Clinical fit of all-ceramic three-unit fixed partial dentures, generated with three different CAD\\/CAM systems

    Microsoft Academic Search

    Sven Reich; Manfred Wichmann; Emeka Nkenke; Peter Proeschel

    2005-01-01

    In this study, the hypothesis was tested that the marginal and internal fit of CAD\\/ CAM fabricated all-ceramic three-unit fixed partial dentures (FPDs) can be as good as in metal-ceramic FPDs. Twenty-four all-ceramic FPDs were fabricated and randomly subdivided into three equally sized groups. Eight frameworks were fabricated using the Digident CAD\\/CAM system (DIGI), another eight frameworks using the Cerec

  4. Comparison of failure rates of adhesive-fixed partial dentures for in vivo and in vitro studies

    Microsoft Academic Search

    M. Behr; U. Hindelang; M. Rosentritt; R. Lang; G. Handel

    2000-01-01

    The objective was to investigate associations between the results of an in vitro and an in vivo study using an artificial\\u000a mouth and a study of adhesive fixed partial dentures (AFPD) begun in 1985 [1]. Twenty extracted human molars and 20 human\\u000a upper incisors were inserted into PMMA resin, 6 mm apart to represent a gap. Two preparation methods (identical

  5. Materials and methods for cleaning dentures.

    PubMed

    Budtz-Jørgensen, E

    1979-12-01

    Proper hygienic care of removable dentures is an important means of maintaining a healthy oral mucosa in denture wearers. Denture cleanliness is often poor due to improper mechanical cleansing and the relative inefficiency of most commercial products for chemical cleansing of dentures. Dentists and patients should realize that microbial plaque on dentures may be harmful to both the oral mucosa and the patient's general health. It is the responsibility of the patient to maintain oral hygiene through a daily home care routine. It is the obligation of the dentist to motivate and instruct the patient and provide the means and methods for plaque control. Future research should be directed to developing solution cleansers which can maintain plaque-free dentures with a daily soaking period of 15 to 30 minutes and not affect the color and surface luster of the denture acrylic resin. PMID:229217

  6. EFFECT OF PONTIC FRAMEWORK DESIGN ON THE FRACTURE RESISTANCE OF IMPLANT-SUPPORTED ALL-CERAMIC FIXED PARTIAL DENTURES

    PubMed Central

    Inan, Ozgur; Secilmis, Asli; Eraslan, Oguz

    2009-01-01

    Objective: The purpose of this study was to compare the fracture resistance of implant-supported all-ceramic fixed partial dentures, which have three different pontic designs. Material and Methods: Two implants were placed in a metal model simulating mandibular left second premolar and mandibular left second molar. Thirty standardized 3-unit all-ceramic fixed partial dentures with biconvex, convex or concave pontic designs were fabricated using IPS e.max system (n=10). Afterwards, specimens were centrally loaded on the pontics until failure with a universal testing machine. Results were analyzed by Kruskal-Wallis and Mann-Whitney U tests at 5% significance level. Results: The fracture resistance values of all-ceramic fixed partial dentures designed with biconvex, convex or concave pontics were 349.71, 438.20 and 300.78 N, respectively. There were no statistically significant differences between the fracture resistances of the groups (p>0.05), except for convex and concave groups (p<0.05 and p=0.009, respectively). Conclusions: Convex design showed the best mechanical properties as demonstrated by the high values of fracture resistance. PMID:19936538

  7. Marginal adaptation analysis performed with en face optical coherence tomography in fixed partial dentures

    NASA Astrophysics Data System (ADS)

    Sinescu, Cosmin; Negrutiu, Meda Lavinia; Antonie, Sergiu; Dobre, George; Bradu, Adrian; Hughes, Michael; Rominu, Mihai; Podoleanu, Adrian Gh.

    2009-02-01

    Frameworks for fixed partial denture made out of dental alloys thought classic techniques currently involve many errors like marginal and internal gaps. The aim of this study is to present alternative technologies in making frameworks from dental alloys using selective laser sintering/ selective laser melting (SLS/ SLM) and to investigate the marginal adaptation of the fixed dental prostheses using the en face optical coherence tomography. These procedures imply the use of a scanning device PROBIS, SMART OPTICS with the help of 3D Dental Scanner software. For digitizing the 3D model we used the Dental Wings Kunde Software. The files obtained were sent to a SLS/ SLM machine, Hint-Els rapidPro, where the CoCr powder was sintered/melt by selectively consolidating successive layers of powder material on top of each other, using thermal energy supplied by a focused and computer controlled laser beam. Through this technique can be produced up to 80 pieces in only one step. A parallel between the classic casting technique and this new technology reveal the least has several advantages: fast finishing time, excellent marginal and internal fit, biocompatibility and superior chemical properties. SLS/ SLM proved to be a promising technology that may overcome the classic ones, because of the superior marginal fit of the fixed dental prostheses to the teeth.

  8. Bone's responses to different designs of implant-supported fixed partial dentures.

    PubMed

    Rungsiyakull, Chaiy; Chen, Junning; Rungsiyakull, Pimduen; Li, Wei; Swain, Michael; Li, Qing

    2015-04-01

    This paper explores the biomechanics and associated bone remodeling responses of two different abutment configurations, namely implant-implant-supported versus tooth-implant-supported fixed partial dentures. Two 3D finite element analysis models are created based upon computerized tomography data. The strain energy density induced by occlusal loading is used as a mechanical stimulus for driving the bone remodeling. To measure osseointegration and stability during healing, a resonance frequency analysis is conducted. At the second premolar peri-implant region, overloading resorption around the neck of implant is identified in both the models over the first 12 months. Stress-shielding around the edentulous region is also observed in both the models with a greater resorption rate found in the implant-implant case. The remodeling and resonance frequency analyses reveal that the tooth-implant scheme offers a higher degree of osseointegration. The remodeling procedure is expected to provide prosthodontists with a modeling tool to assess possible long-term clinical outcomes. PMID:25209424

  9. Possible variation of the human oral bacterial community after wearing removable partial dentures by DGGE.

    PubMed

    Zhu, Xiao; Wang, Shaohai; Gu, Yihai; Li, Xiaoyu; Yan, Hui; Yan, He; Miyoshi, Shin-Ichi; Shi, Lei

    2012-05-01

    Although it is well-known that variations of the microbial community in a specific location of human body may be associated with some diseases, the developing change of the oral microbiota related to oral diseases before and after wearing the removable partial dentures (RPD) is not completely understood. In this study, three kinds of samples (saliva, supra- and subgingival plaque, and oral mucosal surfaces) were collected from the 10-patients group at three different times: before, 1-month and 6-months after the treatment. Ten healthy adults were also selected as the control group. Denaturing gradient gel electrophoresis was applied to identify the bacterial profiles and to analyze the dynamics of the oral microbial population in the pre- and post-therapy. The ANOVA of Repeated Measurement Data indicated that, in the saliva and mucosal surfaces, wearing RPDs caused significant change of numbers of amplicons. As many as 607 amplicons were chosen to cut out and re-amplify by PCR. After cloning and sequencing, a total of 16 bacterial genera were identified. The health-associated genera such as Streptococcus, Neisseria, Rothia, Corynebacterium, Leptotrichia, Gemella, Veillonella, Selenomona and Actinomyces tended to decrease, whereas the disease-associated species including Streptococcus mutans tended to increase. In general, wearing RPDs influenced the diversity of the bacterial species in the oral microbial ecosystem. It is noteworthy that the oral environment will be changed from the healthy status towards the disease status after the treatment. PMID:22806046

  10. Comparative evaluation of retentive properties of acid etched resin bonded fixed partial dentures

    PubMed Central

    Arora, Vimal; Sharma, M.C.; Dwivedi, Ravi

    2013-01-01

    Background Little consensus exist in suitable tooth preparation design and alloy pre-treatment methods for improving the retention of resin bonded fixed partial dentures (RBFPDs). Methods An in-vitro experiment was done with four designs. Group A: standard form, B: wings and proximal slices, C: wings, proximal slice and grooves, D: wings, proximal slice, grooves and occlusal coverage. Alloys were subjected to pre-treatment procedures like Group I: control, II: sand blasting, III: electro etching, IV: tin plating. Debonding forces of the castings were recorded in a universal testing machine and results were analyzed by student's ‘t’ test. Results Group B, C and D showed higher debonding forces compared to A. However, there were no significant differences in mean force values among Groups B, C and D. Group II, III and IV with different alloy pre-treatment methods demonstrated higher values against control. Inter group variations among Group II, III and IV were not significant. Conclusion Tooth preparation with adequate surface extensions and pre-treatment procedures of casting alloys are two parameters that play important role in determining the retentive features of RBFPDs. Different types of tooth preparation designs and alloy pre-treatment methods exert almost similar influence in increasing the retention of acid etched RBFPDs. PMID:24623948

  11. The computer-aided design and rapid prototyping fabrication of removable partial denture frameworks.

    PubMed

    Eggbeer, D; Bibb, R; Williams, R

    2005-05-01

    This study explores the application of computer-aided design and manufacture (CAD/CAM) to the process of electronically surveying a scanned dental cast as a prior stage to producing a sacrificial pattern for a removable partial denture (RPD) metal alloy framework. These are designed to retain artificial replacement teeth in the oral cavity. A cast produced from an impression of a patient's mouth was digitally scanned and the data converted to a three-dimensional computer file that could be read by the computer-aided design (CAD) software. Analysis and preparation were carried out in the digital environment according to established dental principles. The CAD software was then used to design the framework and generate a standard triangulation language (STL) file in preparation for its manufacture using rapid prototyping (RP) methods. Several RP methods were subsequently used to produce sacrificial patterns, which were then cast in a chromium-cobalt alloy using conventional methods and assessed for accuracy of fit. This work demonstrates that CAD/CAM techniques can be used for electronic dental cast analysis, preparation, and design of RPD frameworks. It also demonstrates that RP-produced patterns may be successfully cast using conventional methods and that the resulting frameworks can provide a satisfactory fit. PMID:15934395

  12. Clinical performance and failures of zirconia-based fixed partial dentures: a review literature

    PubMed Central

    Triwatana, Premwara; Nagaviroj, Noppavan

    2012-01-01

    PURPOSE Zirconia has been used in clinical dentistry for approximately a decade, and there have been several reports regarding the clinical performance and survival rates of zirconia-based restorations. The aim of this article was to review the literatures published from 2000 to 2010 regarding the clinical performance and the causes of failure of zirconia fixed partial dentures (FPDs). MATERIALS AND METHODS An electronic search of English peer-reviewed dental literatures was performed through PubMed to obtain all the clinical studies focused on the performance of the zirconia FPDs. The electronic search was supplemented by manual searching through the references of the selected articles for possible inclusion of some articles. Randomized controlled clinical trials, longitudinal prospective and retrospective cohort studies were the focuses of this review. Articles that did not focus on the restoration of teeth using zirconia-based restorations were excluded from this review. RESULTS There have been three studies for the study of zirconia single crowns. The clinical outcome was satisfactory (acceptable) according to the CDA evaluation. There have been 14 studies for the study of zirconia FPDs. The survival rates of zirconia anterior and posterior FPDs ranged between 73.9% - 100% after 2 - 5 years. The causes of failure were veneer fracture, ceramic core fracture, abutment tooth fracture, secondary caries, and restoration dislodgment. CONCLUSION The overall performance of zirconia FPDs was satisfactory according to either USPHS criteria or CDA evaluations. Fracture resistance of core and veneering ceramics, bonding between core and veneering materials, and marginal discrepancy of zirconia-based restorations were discussed as the causes of failure. Because of its repeated occurrence in many studies, future researches are essentially required to clarify this problem and to reduce the fracture incident. PMID:22737311

  13. Effect of different cleansers on the surface of removable partial denture.

    PubMed

    Felipucci, Daniela Nair Borges; Davi, Letícia Resende; Paranhos, Helena Freitas Oliveira; Bezzon, Osvaldo Luiz; Silva, Rodrigo Ferreira; Pagnano, Valéria Oliveira

    2011-01-01

    Removable partial dentures (RPD) demand specific hygienic cleaning and the combination of brushing with immersion in chemical solutions has been the most recommended method for control of biofilm. However, the effect of the cleansers on metallic components has not been widely investigated. This study evaluated the effect of different cleansers on the surface of RPD. Five disc specimens (12 mm x 3 mm metallic disc centered in a 38 x 18 x 4 mm mould filled with resin) were obtained for each experimental situation: 6 solutions [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05% sodium hypochlorite (NaOCl), and distilled water (DW) control] and 2 Co-Cr alloys [DeguDent (DD) and VeraPDI (VPDI)] were used for each experimental situation. A 180-day immersion was simulated and the measurements of roughness (Ra, µm) of metal and resin were analyzed using 2-way ANOVA and Tukey's test. The surface changes and tarnishes were examined with a scanning electronic microscopy (SEM). In addition, energy dispersive x-ray spectrometry (EDS) analysis was carried out at representative areas. Visually, NaOCl and MI specimens presented surface tarnishes. The roughness of materials was not affected by the solutions (p>0.05). SEM images showed that NaOCl and MI provided surface changes. EDS analysis revealed the presence of oxygen for specimens in contact with both MI and NaOCl solutions, which might suggest that the two solutions promoted the oxidation of the surfaces, thus leading to spot corrosion. Within the limitations of this study, it may be concluded that the NaOCl and MI may not be suitable for cleaning of RPD. PMID:22011895

  14. Improving the esthetic replacement of missing anterior teeth: interaction between periodontics and a rotational path removable partial denture.

    PubMed

    Goncalves, Leticia Machado; Bezerra-Junior, Jose Ribamar Sabino; Benatti, Bruno Braga; Santana, Ivone Lima

    2011-01-01

    The rotational path of insertion concept for removable partial dentures (RPDs) can be used in esthetically demanding situations. This clinical report describes the treatment of a patient with an anterior maxillary edentulous area using a rotational path RPD. To optimally improve gingival esthetics and to allow proximal retention on the surveyors, a crown-lengthening surgical procedure was performed prior to prosthetic treatment on all teeth involved in this rehabilitation. When correctly planned and fabricated, this prosthesis allows excellent functional and esthetic results, minimizes tooth preparation, and reduces the tendency toward plaque accumulation. PMID:21903542

  15. Factors that augment the role of direct retainers in mandibular distal-extension removable partial dentures.

    PubMed

    Donahue, T J

    1988-12-01

    Several features of RPD design that augment direct retainer design were identified. They are as follows: 1. The duplication of direct retainer function by other prosthesis components 2. Physiologic adjustment of the framework to assure contacts with abutment teeth that are consistent with the design and intended functions of the components and that transfer stress in a manner those teeth are designed to accept 3. Intimate adaptation of denture bases to the residual mucosa, with recall visits to monitor this adaptation 4. Specific loading of the denture bases through selective placement of artificial teeth 5. Splinting of abutment teeth PMID:3060602

  16. The effect of denture stability on bite force and muscular effort.

    PubMed

    Caloss, R; Al-Arab, M; Finn, R A; Throckmorton, G S

    2011-06-01

    This study tested the hypothesis that denture instability limits the amount of voluntary muscular effort generated by denture wearers. Seventeen edentulous subjects (seven men, 10 women; mean age 60·3 ± 13·0 years) with newly acquired implant-retained mandibular overdentures and a conventional maxillary denture participated. Maximum bite forces and corresponding electromyographic (EMG) activity from the temporalis and masseter muscles (bilaterally) were recorded under two experimental conditions: (i) Unilateral premolar and molar bites without additional support, and (ii) premolar and molar bites with bite block support on the opposite side. In addition, EMG values alone were recorded during maximum clenching without any transducer between the upper and lower dentures. The level of muscular effort was significantly higher with greater denture support. These results indicate that denture instability probably prevents denture wearers from using the full potential of their jaw muscles, especially during unilateral biting and chewing, even with two implants supporting the mandibular dentures. PMID:21050259

  17. Comparative Evaluation of Marginal Accuracy of a Cast Fixed Partial Denture Compared to Soldered Fixed Partial Denture Made of Two Different Base Metal Alloys and Casting Techniques: An In vitro Study.

    PubMed

    Jei, J Brintha; Mohan, Jayashree

    2014-03-01

    The periodontal health of abutment teeth and the durability of fixed partial denture depends on the marginal adaptation of the prosthesis. Any discrepancy in the marginal area leads to dissolution of luting agent and plaque accumulation. This study was done with the aim of evaluating the accuracy of marginal fit of four unit crown and bridge made up of Ni-Cr and Cr-Co alloys under induction and centrifugal casting. They were compared to cast fixed partial denture (FPD) and soldered FPD. For the purpose of this study a metal model was fabricated. A total of 40 samples (4-unit crown and bridge) were prepared in which 20 Cr-Co samples and 20 Ni-Cr samples were fabricated. Within these 20 samples of each group 10 samples were prepared by induction casting technique and other 10 samples with centrifugal casting technique. The cast FPD samples obtained were seated on the model and the samples were then measured with travelling microscope having precision of 0.001 cm. Sectioning of samples was done between the two pontics and measurements were made, then the soldering was made with torch soldering unit. The marginal discrepancy of soldered samples was measured and all findings were statistically analysed. The results revealed minimal marginal discrepancy with Cr-Co samples when compared to Ni-Cr samples done under induction casting technique. When compared to cast FPD samples, the soldered group showed reduced marginal discrepancy. PMID:24605006

  18. The effect of fiber reinforcement type and water storage on strength properties of a provisional fixed partial denture resin.

    PubMed

    Uzun, Gülay; Keyf, Filiz

    2003-04-01

    Fracture resistance of provisional restorations is an important clinical concern. This property is directly related to transverse strength. Strengthening of provisional fixed partial dentures may result from reinforcement with various fiber types. This study evaluated the effect of fiber type and water storage on the transverse strength of a commercially available provisional resin under two different conditions. The denture resin was reinforced with either glass or aramid fiber or no reinforcement was used. Uniform samples were made from a commercially available autopolymerizing provisional fixed partial denture resin. Sixteen bar-shaped specimens (60 x 10 x 4 mm) were reinforced with pre-treated epoxy resin-coated glass fibers, with aramid fibers, or with no fibers. Eight specimens of each group, with and without fibers, were tested after 24 h of fabrication (immediate group), and after 30-day water storage. A three-point loading test was used to measure the transverse strength, the maximal deflection, and the modulus of elasticity. The Kruskal-Wallis Analysis of Variance was used to examine differences among the three groups, and then the Mann-Whitney U Test and Wilcoxon Signed Ranks Test were applied to determine pair-wise differences. The transverse strength and the maximal deflection values in the immediate group and in the 30-day water storage group were not statistically significant. In the group tested immediately, the elasticity modulus was found to be significant (P = 0.042). In the 30-day water storage group, all the values were statistically insignificant. The highest transverse strength was displayed by the glass-reinforced resin (66.25MPa) in the immediate group. The transverse strength value was 62.04MPa for the unreinforced samples in the immediate group. All the specimens exhibited lower transverse strength with an increase in water immersion time. The transverse strength value was 61.13 MPa for the glass-reinforced resin and was 61.24 MPa for the unreinforced resin. The aramid-reinforced resin decreased from 62.29 to 58.77 MPa. The addition of fiber reinforcement enhanced the physical properties (the transverse strength, the maximal deflection, the modulus of elasticity) of the processed material over that seen with no addition of fiber. Water storage did not statistically affect the transverse strength of the provisional denture resin compared to that of the unreinforced resin. The transverse strength was lowered at water storage but it was not statistically significant. The transverse strength was enhanced by fiber addition compared to the unreinforced resin. The glass fiber was superior to the other fiber. Also the modulus of elasticity was enhanced by fiber addition compared to the unreinforced resin. PMID:12797420

  19. A short-term clinical follow-up study of superplastic titanium alloy for major connectors of removable partial dentures

    Microsoft Academic Search

    Noriyuki Wakabayashi; Minoru Ai

    1997-01-01

    Statement of problem . Superplastic forming of Ti-6Al-4V alloy has been used in the fabrication of a removable denture framework. The method provides the titanium alloy denture framework with excellent physical properties not seen in cast titanium prostheses.Purpose . This study describes the technical procedure for fabricating removable dentures with this type of framework and evaluates clinical applications of the

  20. Sabit Protetik Restorasyonlarin Söküm Nedenleri ve Yöntemlerinin De?erlendirilmesi An Evaluation of the Causes and the Methods of Removal of Fixed Partial Dentures

    Microsoft Academic Search

    Hatice ULUER; Gökhan AKSOY; Ege Üniversitesi

    Objective: The aim of this study was to evaluate the fixed partial dentures (FPDs) from an aspect of the mean survival time of restorations, location where they were prepared, type of restorative material, crown removal technique and removal indication. Methods: This study was carried on 115 patients (85 women and 30 men) who had 15 (13%) full metal crown restorations,

  1. International telephone code used for citizenship identification in a denture.

    PubMed

    Matsumura, Hideo; Shimoe, Saiji; Nagano, Kiyoshi; Tanoue, Naomi

    2007-12-01

    This case report describes a simple method for identifying the citizenship of a denture wearer by marking the telephone country code number inside the denture base. A wax pattern for the denture framework was prepared on the refractory cast. A piece of embossing tape, containing the country code (81, Japan), Japanese prefectural code, and abbreviation of the dental clinic where the denture was fabricated, was placed on the metal framework. A titanium-aluminum-niobium (Ti-6Al-7Nb) alloy was cast in the mold, and the denture was then fabricated by the conventional method. The casting satisfactorily reproduced the embossed letters, and the plate was identifiable through the gingiva-colored acrylic denture base resin. Since an embossed metal plate integrated with the skeleton is embedded in the denture base resin material, the current denture marking technique serves as a simple procedure for insertion of an undegradable denture identification mark which makes it possible to identify the nationality of the denture wearer. PMID:18195519

  2. Effect of different cleansers on the weight and ion release of removable partial denture: an in vitro study

    PubMed Central

    FELIPUCCI, Daniela N.B.; DAVI, Letícia R.; PARANHOS, Helena F.O.; BEZZON, Osvaldo L.; SILVA, Rodrigo F.; BARBOSA JUNIOR, Fernando; PAGNANO, Valéria O.

    2011-01-01

    Objective Removable partial dentures (RPD) require different hygiene care, and association of brushing and chemical cleansing is the most recommended to control biofilm formation. However, the effect of cleansers has not been evaluated in RPD metallic components. The aim of this study was to evaluate in vitro the effect of different denture cleansers on the weight and ion release of RPD. Material and Methods Five specimens (12x3 mm metallic disc positioned in a 38x18x4 mm mould filled with resin), 7 cleanser agents [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05% sodium hypochlorite (NaOCl), and distilled water (DW) (control)] and 2 cobalt-chromium alloys [DeguDent (DD), and VeraPDI (VPDI)] were used for each experimental situation. One hundred and eighty immersions were performed and the weight was analyzed with a high precision analytic balance. Data were recorded before and after the immersions. The ion release was analyzed using mass spectrometry with inductively coupled plasma. Data were analyzed by two-way ANOVA and Tukey HSD post hoc test at 5% significance level. Results Statistical analysis showed that CT and MI had higher values of weight loss with higher change in VPDI alloy compared to DD. The solutions that caused more ion release were NaOCl and MI. Conclusions It may be concluded that 0.05% NaOCl and Medical Interporous tablets are not suitable as auxiliary chemical solutions for RPD care. PMID:21986653

  3. Treatment with double crown-retained removable partial dentures and oral health-related quality of life in middle- and high-aged patients.

    PubMed

    Grossmann, Anne-Christiane; Hassel, Alexander J; Schilling, Oliver; Lehmann, Franziska; Koob, Andreas; Rammelsberg, Peter

    2007-01-01

    The objective of this study was to assess the change in oral health-related quality of life following treatment with double crown-retained removable partial dentures (RPDs). Sixty RPDs in 54 patients (mean age: 65 years) were fabricated and retained with either galvanoformed telescopic secondary crowns (n = 30) or conical secondary crowns (n = 30). The Oral Health Impact Profile (OHIP) was assessed pretreatment and during 6- and 12-month follow-up appointments. Patient assessment of denture-satisfaction was also recorded on a Lickert-type scale. A decrease in the OHIP-sum score was significant after treatment for both groups, but not between the experimental groups. The denture assessment showed good values for both groups. Treatment with different double crown-retained RPDs improved oral health-related quality of life. PMID:18069364

  4. Occlusion of artificial teeth in partial dentures in the "chewing center"--first exploratory population-based evaluations.

    PubMed

    Kordass, B; Ruge, S; Quooss, A; Hugger, A; Mundt, T

    2014-01-01

    Occlusal performance is a substantial determinant of the quality of dental prosthetic restorations. In the follow-up (SHIP 1) to the Study of Health in Pomerania (SHIP), a representative population of 3300 subjects was studied in the first exploratory evaluation of the occlusion of artificial teeth in the chewing center (first molar region) of partial dentures. A digital analysis of interocclusal records of habitual intercuspation position (ICP) was performed using the Greifswald Digital Analyzing System (GEDAS), a software package that identifies contact points as transparent areas. 562 subjects (280 men aged 61.7 ± 11.9 years and 282 women aged 60.7 ± 10.7 years) had maxillary removable partial dentures (RPDs), and 619 (271 men aged 65.0 ± 11.5 years and 348 women aged 62.4 ± 10.6 years) had mandibular RPDs. Most RPDs were retained with either attachment retainers (11.7% maxilla, 11.7% mandible), cast clasps (38.4% maxilla, 40.7% mandible), telescopes with double crowns (15.7% maxilla, 19.1% mandible), or wrought wire clasps (16.4% maxilla, 8.2% mandible). Some had a combination of different retention elements. The mean number of artificial teeth was 7.8 ± 2.9 in the maxilla and 7.5 ± 3.0 in the mandible. Only the artificial teeth (first molars) in mandibular partial dentures showed differences in the frequency of occlusal contacts between groups (chi-square test). Of these, telescopic crown-retained RPDs had the highest frequency of occlusal contacts (74.4% at tooth 36 and 77.1% at tooth 46), and wrought wire-retained RPDs had the lowest (48.4% at tooth 36 and 45.2% at tooth 46). The results for RPDs with a free-end saddle were comparable and analogous; contact frequencies for those with an interdental saddle did not differ significantly. Notably, the overall frequency of occlusal contacts was greater for tooth 46 (62.9%) than for tooth 36. In conclusion, when replacing teeth in the chewing center, particularly in the mandible, telescopic crown-retained RPDs offer a distinct advantage in terms of occlusal contacts and thus provide better occlusal stability. PMID:25558759

  5. Maxillary Rehabilitation Using a Removable Partial Denture with Attachments in a Cleft Lip and Palate Patient: A Clinical Report.

    PubMed

    Palmeiro, Marina Rechden Lobato; Piffer, Caroline Scheeren; Brunetto, Vivian Martins; Maccari, Paulo César; Shinkai, Rosemary Sadami Arai

    2014-06-27

    Clefts of the lip and/or palate (CLP) are oral-facial defects that affect health and overall quality of life. CLP patients often need multidisciplinary treatment to restore oral function and esthetics. This paper describes the oral rehabilitation of a CLP adult patient who had maxillary bone and tooth loss, resulting in decreased occlusal vertical dimension. Functional and cosmetic rehabilitation was achieved using a maxillary removable partial denture (RPD) attached to telescopic crowns. Attachment-retained RPDs may be a cost-effective alternative for oral rehabilitation in challenging cases with substantial loss of oral tissues, especially when treatment with fixed dental prostheses and/or dental implants is not possible. PMID:24975940

  6. Denture plaque and denture cleansers.

    PubMed

    Abelson, D C

    1981-04-01

    Literature concerning the relationship between denture plaque, oral pathology, and the nature and effectiveness of the products commercially available for cleaning dentures has been reviewed. The literature reports indicate that (1) plaque on the tissue surface side of the denture is unquestionably a major etiologic factor in the pathogenesis of denture stomatitis, inflammatory papillary hyperplasia, and chronic candidiasis and (2) there are shortcomings in the popular products used by the public to clean their dentures. The protocol and results of a study to test the plaque removal effectiveness of a new denture cleansing product are described. In this study, the plaque removal effectiveness of the ultrasonic device tested, when used with water alone, was found to be substantially greater than that of two popular alkaline-peroxide soak-type denture cleansers, Efferdent and Polident. PMID:6939844

  7. Effect of the Number of Implants on Stress Distribution of Anterior Implant-Supported Fixed Prostheses Combined with a Removable Partial Denture: A Finite Element Analysis

    PubMed Central

    Mahshid, Minoo; Geramy, Allahyar; Ejlali, Massoud; Sedaghat Monfared, Majid; Rezvani Habib Abadi, Shirin

    2014-01-01

    Objective: The main goal of this study was to evaluate differences in stress distribution relevant to the number of implants under an anterior bridge when combined with a removable partial denture in the posterior region. Materials and Methods: Four three-dimensional finite element models (3D FEM) were designed from a mandible containing an implant-supported bridge extending between canines, and a bilateral distal extension removable partial denture. A nonrigid connection was selected as the attachment method between the partial denture and the anterior implant-supported fixed prosthesis; 2, 3, 4 and 5 implants supporting the bridge all with 10mm length and 3.8 mm diameter were assessed. With the aid of the finite element program ANSYS 8.0, the models were loaded and von Mises stresses were evaluated. Results: In spongy bone, stress forces showed a decrease from 2 implants to 4 implants but showed an increase in the 5-implant model. Stresses on cortical bone of terminal implants were in similar range in the 2-, 3- and 4-implant models. While, in the 5-implant model the amount of stresses on terminal implants increased dramatically. The stresses on implants were nearly similar in all models, with the greatest amount on terminal implants. Conclusion: Within the limitations of this study, 2-, 3- and 4-implant models showed less stress on cortical and spongy bone in comparison with the 5-implant model. The stresses transferred to implants were nearly similar. PMID:25628669

  8. Influence of posterior dental arch length on brain activity during chewing in patients with mandibular distal extension removable partial dentures.

    PubMed

    Shoi, K; Fueki, K; Usui, N; Taira, M; Wakabayashi, N

    2014-07-01

    It is well known that shortened dental arch decreases masticatory function. However, its potential to change brain activity during mastication is unknown. The present study investigates the effect of a shortened posterior dental arch with mandibular removable partial dentures (RPDs) on brain activity during gum chewing. Eleven subjects with missing mandibular molars (mean age, 66.1 years) on both sides received experimental RPDs with interchangeable artificial molars in a crossover trial design. Brain activity during gum chewing with RPDs containing (full dental arch) and lacking artificial molars (shortened dental arch) was measured using functional magnetic resonance imaging. Additionally, masticatory function was evaluated for each dental arch type. Food comminuting and mixing ability and the perceived chewing ability were significantly lower in subjects with a shortened dental arch than those with a full dental arch (P < 0.05). Brain activation during gum chewing with the full dental arch occurred in the middle frontal gyrus, primary sensorimotor cortex extending to the pre-central gyrus, supplementary motor area, putamen, insula and cerebellum. However, middle frontal gyrus activation was not observed during gum chewing with the shortened dental arch. These results suggest that shortened dental arch affects human brain activity in the middle frontal gyrus during gum chewing, and the decreased middle frontal gyrus activation may be associated with decreased masticatory function. PMID:24697794

  9. In Vitro Assessment of Single-Retainer Tooth-Colored Adhesively Fixed Partial Dentures for Posterior Teeth

    PubMed Central

    Bortolotto, Tissiana; Monaco, Carlo; Onisor, Ioana; Krejci, Ivo

    2010-01-01

    The purpose of this paper was to investigate, by means of marginal adaptation and fracture strength, three different types of single retainer posterior fixed partial dentures (FPDs) for the replacement of a missing premolar. Two-unit cantilever FPDs were fabricated from composite resin, feldspathic porcelain, and fiber-reinforced composite resin. After luting procedures and margin polishing, all specimens were subjected to a Scanning Electron Microscopic marginal evaluation both prior to and after thermomechanical loading with a custom made chewing simulator comprising both thermal and mechanical loads. The results indicated that the highest score of marginal adaptation, that is, the closest score to 100% of continuous margins, at the tooth-composite resin interface was attained by the feldspathic porcelain group (88.1% median), followed by the fiber-reinforced composite resin group (78.9% median). The worse results were observed in the composite resin group (58.05% median). Fracture strength was higher in feldspathic porcelain (196N median) when compared to resin composite (114.9 N median). All the fixed prostheses made of fiber-reinforced composite resin detached from the abutment teeth before fracturing, suggesting that the adhesive surface's retainer should be increased. PMID:20652071

  10. All-ceramic fixed partial dentures designed according to the DC-Zirkon technique. A 2-year clinical study.

    PubMed

    Vult von Steyern, P; Carlson, P; Nilner, K

    2005-03-01

    The aim of the study was to investigate whether the properties of a pre-sintered, hot isostatic post-compacted (HIP) ZrO2 are adequate for use in three-five-unit fixed partial dentures (FPDs) and to evaluate the clinical results. Twenty three-five-unit FPDs were fabricated for 18 patients on a total of 56 abutments. They were all made on abutments cut with a shoulder preparation and cemented with a zinc phosphate cement. They were clinically followed for 24 months. After 24 months all FPDs were still in use without any fractures or clinical wear but in three cases (15%) minor chip-of fractures were observed. Marginal integrity was rated excellent at 45 abutments and acceptable at 11. Within the limitations of this 2-year clinical follow-up study, FPDs made of pre-sintered HIP ZrO2 core material veneered with a compatible ceramic is an acceptable alternative in the fabrication of FPDs with the extensions investigated in this study. Special attention, however, must be paid to designing the core for an occlusal shape that provides sufficient support for the veneer. PMID:15707428

  11. Clinical evaluation of the essential oil of Pelargonium graveolens for the treatment of denture stomatitis

    PubMed Central

    Sabzghabaee, Ali Mohammad; Shirdare, Zahra; Ebadian, Behnaz; Aslani, Abolfazl; Ghannadi, Alireza

    2011-01-01

    Background: Natural products are proved to play a good role as an alternative to synthetic chemicals in clinical conditions. Previous studies showed that Pelargonium graveolens has anti-inflammatory and antifungal activity against Candida albicans. The aim of this study was to evaluate the efficacy of essential oil of Pelargonium graveolens in the treatment of denture stomatitis. Materials and Methods: In this double-blind randomized clinical trial conducted in Isfahan (Iran), 80 (51 females and 29 males) eligible wearers of complete denture were included. According to the patients’ profiles number, they randomly divided to 2 groups of 40 patients’ case and 40 patients control treated with Pelargonium 1% gel or placebo, respectively. They were recommended to apply the gel twice daily for a 14-day course. All data were analyzed using SPSS® for windows (v.18). We have used the ?2 test for analyzing qualitative and Student t-test for quantitative data considering as P<0.05 as significant. Results: According to mycological data and clinical observation after treatment in the case group, 34% of patients had been improved completely, 56% partially and 10% had no improvement. In the control group, 5% of patients had complete recovery, 25% partial recovery, and 70% no improvement. A significant reduction in fungal growth was observed in case group rather than the control group (P value<0.0001). Conclusion: It seems that the application of a 1% Geranium oil topical gel formulation is more effective than placebo in the treatment of denture stomatitis. PMID:23372587

  12. Factors triggering the oral mucosal lesions by complete dentures.

    PubMed

    Turker, Sebnem Begum; Sener, I?il Damla; Koçak, Ay?e; Yilmaz, Sertan; Ozkan, Yasemin Kulak

    2010-01-01

    Oral mucosal lesions may represent acute or chronic reactions to factors related with dentures. The aim of this study was to determine the frequency of the oral lesions related to gender, age, the length of time of denture usage, the balance of denture and cleaning methods and frequency. The 106 patients who have old complete dentures came to the Dental Faculty of Marmara University, Istanbul (Turkey) to have new complete dentures were asked to participate in the investigation. The subjects (51 men and 55 women) were 37-80 years of age with a mean age of 60.28+/-10.52 years. All main factors were estimated in subgroups: cleaning methods and frequency were divided into 3 subgroups respectively as toothbrush and toothpaste/soap, denture cleansing tablets and sodium carbonate, and 3 times a day, everyday, every 3 day and once a week. The data obtained was evaluated by One-way ANOVA, Mann-Whitney U-test, Kruskal-Wallis-test, Student t-test and chi(2)-test. The level of statistical significance was set at p<0.05. The patients displayed statistically significant differences in the topics of the length of time of denture usage and the balance of denture in terms of retention. The complete denture wearers should be educated in the importance of periodic examination due to the changing of supporting tissues for detection early mucosal lesions to maintain their oral and dentures hygiene in optimum level. PMID:19819567

  13. The effect of four sprue shapes on the quality of cobalt-chromium cast removable partial denture frame-works

    PubMed Central

    Viswambaran, M.; Agarwal, S. K.

    2013-01-01

    Statement of Problem: Sprue design is a factor that controls the velocity and adequate supply of metal to the mould. Currently various manufacturers recommend different shapes of sprue, which have not been advocated in textbooks and literature is lacking for their routine applications. Purpose: This in vitro study was carried out to determine the efficacy of four sprue shapes in producing complete, void free cobalt-chrome removable partial denture frameworks. Materials and Methods: A brass metal die with a Kennedy class III, modification 1, partially edentulous arch was used and four sprue shapes (Group A-Ribbon, Group B-Square, Group C-Round and Group D- Round with reservoir) were evaluated. 40 refractory casts were made, 10 wax patterns for each sprue design were waxed up, invested with phosphate bonded investment material and castings done with induction casting machine by the same operator under standardized protocols. The cast frameworks were evaluated for 1. The defects observed visually before finishing and polishing procedures, 2. Fit on the master die as seen with naked eye and 3. Defects on radiographic evaluation. Data were tabulated and statistically analyzed with 1-way ANOVA followed by Student ‘t’ test. Results: The results differed significantly (P < 0.0001) between the Groups with maximum defects in the castings of Group A followed in decreasing order by Group B, Group C and Group D. When comparing between the Groups (P < 0.05), the defects in Groups C and D was significantly lower than Group A and Group B. Conclusions: Round sprues with reservoir produced most satisfactory fit of castings with minimum number of internal and external defects. PMID:24014998

  14. Biting and Chewing in Overdentures, Full Dentures, and Natural Dentitions

    Microsoft Academic Search

    F. A. Fontijn-Tekamp; A. P. Slagter; A. Van Der Bilt; M. A. Van'T Hof; D. J. Witter; W. Kalk; J. A. Jansen

    2000-01-01

    It has been suggested that the provision of dental implants can improve the oral function of subjects with severely resorbed mandibles, possibly restoring function to the level experienced by satisfied wearers of conventional complete dentures. Nevertheless, a quantitative comparison has never been made and can be drawn from the literature only with difficulty, since studies differ greatly in methodology. To

  15. Living with Your Dentures

    MedlinePLUS

    ... Relining and Rebasing Adjusting to Your Dentures Denture Adhesives When people get dentures for the first time, ... will slip or fall out. Using a denture adhesive can ease some of these worries and can ...

  16. The path of placement of a removable partial denture: a microscope based approach to survey and design.

    PubMed

    Mamoun, John Sami

    2015-02-01

    This article reviews the topic of how to identify and develop a removable partial denture (RPD) path of placement, and provides a literature review of the concept of the RPD path of placement, also known as the path of insertion. An optimal RPD path of placement, guided by mutually parallel guide planes, ensures that the RPD flanges fit intimately over edentulous ridge structures and that the framework fits intimately with guide plane surfaces, which prevents food collecting empty spaces between the intaglio surface of the framework and intraoral surfaces, and ensures that RPD clasps engage adequate numbers of tooth undercuts to ensure RPD retention. The article covers topics such as the causes of obstructions to RPD intra-oral seating, the causes of food collecting empty spaces that may exist around an RPD, and how to identify if a guide plane is parallel with the projected RPD path of placement. The article presents a method of using a surgical operating microscope, or high magnification (6-8x or greater) binocular surgical loupes telescopes, combined with co-axial illumination, to identify a preliminary path of placement for an arch. This preliminary path of placement concept may help to guide a dentist or a dental laboratory technician when surveying a master cast of the arch to develop an RPD path of placement, or in verifying that intra-oral contouring has aligned teeth surfaces optimally with the RPD path of placement. In dentistry, a well-fitting RPD reduces long-term periodontal or structural damage to abutment teeth. PMID:25722842

  17. Fracture Resistance of Composite Fixed Partial Dentures Reinforced with Pre-impregnated and Non-impregnated Fibers

    PubMed Central

    Mosharraf, Ramin; Torkan, Sepideh

    2012-01-01

    Background and aims The mechanical properties of fiber-reinforced composite fixed partial dentures (FPDs) are af-fected by fiber impregnation. The aim of this in vitro study was to compare the fracture resistance of composite fixed partialdentures reinforced with pre-impregnated and non-impregnated fibers. Materials and methods Groups (n=5) of three-unit fiber-reinforced composite FPDs (23 mm in length) from maxillary second premolar to maxillary second molar were fabricated on two abutments with pontic width of 12 mm. One group was fabricated as the control group with composite (Gradia) and the other two groups were fabricated with composite (Gradia) reinforced with pre-impregnated fiber (Fibrex ribbon) and non-impregnated fiber (Fiber braid), respectively. The specimens were stored in distilled water for one week at 37°C and then tested in a universal testing machine by means of a three-point bending test. Statistical analysis consisted of one-way ANOVA and a post hoc Scheffé’s test for the test groups (?=0.05). Results Fracture resistance (N) differed significantly between the control group and the other two groups (P<0.001), but there were no statistically significant differences between the pre-impregnated and non-impregnated groups (P=0.565). The degree of deflection measured (mm) did not differ significantly between the three groups (P=0.397), yet the mean deflection measured in pre-impregnated group was twice as that in the other two groups. Conclusion Reinforcement of composite with fiber might considerably increase the fracture resistance of FPDs; how-ever, the type of the fiber used resulted in no significant difference in fracture resistance of FPD specimens. PMID:22991628

  18. Evaluation of stress patterns produced by implant-retained overdentures and implant-retained fixed partial denture.

    PubMed

    Mazaro, José Vitor Quinelli; Filho, Humberto Gennari; Vedovatto, Eduardo; Pellizzer, Eduardo Piza; Rezende, Maria Cristina Rosifini Alves; Zavanelli, Adriana Cristina

    2011-11-01

    The purposes of this study were to photoelastically measure the biomechanical behavior of 4 implants retaining different cantilevered bar mandibular overdenture designs and to compare a fixed partial denture (FPD). A photoelastic model of a human edentulous mandible was fabricated, which contained 4 screw-type implants (3.75 × 10 mm) embedded in the parasymphyseal area. An FPD and 3 overdenture designs with the following attachments were evaluated: 3 plastic Hader clips, 1 Hader clip with 2 posterior resilient cap attachments, and 3 ball/O-ring attachments. Vertical occlusal forces of 100 N were applied between the central incisor and unilaterally to the right and left second premolars and second molars. Stresses that developed in the supporting structure were monitored photoelastically and recorded photographically. The results showed that the anterior loading, the overdenture with 3 plastic Hader clips, displayed the largest stress concentration at the medium implant. With premolar loading, the FPD and overdenture with 3 plastic Hader clips displayed the highest stresses to the ipsilateral terminal implant. With molar loading, the overdenture with 3 ball/O-ring attachments displayed the most uniform stress distribution in the posterior edentulous ridge, with less overloading in the terminal implant. It was concluded that vertical forces applied to the bar-clip overdenture and FPD created immediate stress patterns of greater magnitude and concentration on the ipsilateral implants, whereas the ball/O-ring attachments transferred minimal stress to the implants. The increased cantilever in the FPD caused the highest stresses to the terminal implant. PMID:22067869

  19. Marginal fit of alumina-and zirconia-based fixed partial dentures produced by a CAD/CAM system.

    PubMed

    Tinschert, J; Natt, G; Mautsch, W; Spiekermann, H; Anusavice, K J

    2001-01-01

    Clinical long-term success of all-ceramic dental restorations can be significantly influenced by marginal discrepancies. As a result, this in vitro study evaluated the marginal fit of alumina- and zirconia-based fixed partial dentures (FPDs) machined by the Precident DCS system. Different master steel models of three-, four- and five-unit posterior FPDs with an 0.8 mm chamfer preparation were produced. FPDs made of DC-Zirkon and In-Ceram Zirconia core ceramics were machined by the Precident DCS system. The marginal fit of the milled frameworks placed on the master steel models was determined by a replica technique using a light-body silicone to fill the discrepancies between crown and tooth and a heavy-body material to stabilize the light-body impression material. The impressions were poured into an epoxy resin material and each model was cross-sectioned with a low speed diamond saw to better visualize marginal discrepancies. The marginal fit of the FPDs was evaluated by scanning electron microscopy. The measurements of the marginal fit exhibited mean marginal discrepancies in a range between 60.5 and 74.0 microm, mean marginal gaps in a range from 42.9 to 46.3 microm, mean vertical discrepancies in a range from 20.9 to 48.0 microm and mean horizontal discrepancies in the range of 42.0 to 58.8 microm. Statistical data analysis was performed using the non-parametric test of Kruskal-Wallis and Mann-Whitney. The analysis revealed no significant differences (p>0.05) between the mean marginal gaps and vertical and horizontal discrepancies. However, for some FPDs the mean values of the marginal discrepancies were significantly different (p < or =0.05). The wide range of the measured values may be attributed to the complex geometrical design of long span FPDs and difficulties regarding the milling process of brittle ceramic materials. Based on the selection of 100 microm as the limit of clinical acceptability, the results of this study can conclude that the level of marginal fit for alumina- and zirconia-based FPDs achieved with the Precident DCS system meet the clinical requirements. PMID:11504436

  20. Quality of communication and master impressions for the fabrication of cobalt chromium removable partial dentures in general dental practice in England, Ireland and Wales in 2009.

    PubMed

    Kilfeather, G P; Lynch, C D; Sloan, A J; Youngson, C C

    2010-04-01

    The aim of this study was to investigate the quality of communication and master impressions for the fabrication of cobalt chromium removable partial dentures (RPDs) in general dental practice in England, Ireland and Wales in 2009. Two hundred and ten questionnaires were distributed to 21 laboratories throughout England, Ireland and Wales. Information was collected regarding the quality of written communication and selection of master impression techniques for cobalt chromium partial dentures in general dental practice. One hundred and forty-four questionnaires were returned (response rate = 68%). Alginate was the most popular impression material being used in 58% of cases (n = 84), while plastic stock trays were the most popular impression tray, being used in 31% of cases (n = 44). Twenty-four per cent (n = 35) of impressions were not adequately disinfected. Opposing casts were provided in 81% of cases (n = 116). Written instructions were described as being 'clear' in 31% of cases (n = 44). In 54% of cases (n = 76), the technician was asked to design the RPD. Based on the findings of this study, written communication for cobalt chromium RPDs by general dental practitioners is inadequate. This finding is in breach of relevant contemporary legal and ethical guidance. There are also concerns in relation to the fabrication process for this form of prosthesis, particularly, in relation to consideration of occlusal schemes. PMID:20085617

  1. Trial of an experimental castor oil solution for cleaning dentures.

    PubMed

    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 (?=0.05). Tested solutions presented significant difference (Fr=51.67; p<0.001). Saline and NaOCl were significantly different (median: 2.0% and 0.0%) whereas Polident and castor 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. PMID:24789291

  2. A randomized clinical trial comparing the efficacy of mandibular implant-supported overdentures and conventional dentures in diabetic patients. Part II. Comparisons of masticatory performance

    Microsoft Academic Search

    Neal R. Garrett; Krishan K. Kapur; Michael O. Hamada; Eleni D. Roumanas; Earl Freymiller; Thomas Han; Randy M. Diener; Seymour Levin; Tenglang Chen

    1998-01-01

    Statement of problem. Convincing evidence is lacking to demonstrate the functional superiority of mandibular implant-supported overdentures over conventional dentures.Purpose. This randomized clinical trial was conducted to compare masticatory functional effectiveness of mandibular implant-supported overdentures and conventional dentures in diabetic denture wearers with clinically acceptable metabolic control.Methods. A total of 102 edentulous diabetic patients, treated with or without insulin, were randomized

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

    PubMed Central

    CRUZ, Patrícia Costa; de ANDRADE, Ingrid Machado; PERACINI, Amanda; de SOUZA-GUGELMIN, Maria Cristina Monteiro; SILVA-LOVATO, Cláudia Helena; de SOUZA, Raphael Freitas; PARANHOS, Helena de Freitas Oliveira

    2011-01-01

    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 for cleaning complete dentures. PMID:22231005

  4. Discrimination against contact lens wearers.

    PubMed

    Blais, B R

    1998-10-01

    Employers' attitudes toward the use of contact lenses at work have become less discriminatory as lenses have improved and numerous studies have demonstrated their safety, provided that additional personal protective equipment is used when necessary. In 1994, the Occupational Safety and Health Administration published its relevant Standard (29 CFR 1910), stating that "contact lenses do not pose additional hazards to the wearer...". Accommodations required by wearers of contact lenses must comply with Title I of the Americans with Disabilities Act. However, many companies still oppose their use. The recently published policy of the American College of Occupational and Environmental Medicine and the American Academy of Ophthalmology on the use of contact lenses should lead to their wider acceptance. Elements of a corporate contact lens policy are outlined. International aspects are summarized as well. PMID:9800172

  5. Fabrication of a maxillary posterior fixed partial denture with a type 4 gold alloy and a dual-polymerizing indirect composite.

    PubMed

    Matsumura, Hideo; Mori, Shuichi; Tanoue, Naomi

    2008-03-01

    The aim of the present study was to design and fabricate a maxillary posterior fixed partial denture (FPD) made of a type 4 gold alloy and an indirect composite. Unlike the conventional framework design of a resin veneered restoration, cut-back was extended approximately 1/4 to 1/3 width in the occlusal table of the buccal cusp. Multiple retentive beads 150-200 mum in diameter were placed on the metal surface to be veneered. The gold alloy was cast in a cristobalite mold using a centrifugal casting machine. The cut surface with the retentive beads was air-abraded with alumina, and a priming agent (Alloy Primer) that contained triazine dithione monomer (VTD) was applied. A tooth-colored veneer was then fabricated with a highly loaded light- and heat-cured composite material (Estenia). This design and procedure can be applied as a standardized laboratory technique for fabrication of maxillary posterior restorations and FPDs. PMID:18403895

  6. EFFICACY OF BIOFILM DISCLOSING AGENT AND OF THREE BRUSHES IN THE CONTROL OF COMPLETE DENTURE CLEANSING

    PubMed Central

    da Silva, Cláudia Helena Lovato; Paranhos, Helena de Freitas Oliveira

    2006-01-01

    Objective: This report evaluated the efficacy of three brushes and one biofilm disclosing agent in complete denture cleansing. Methods: Twenty-seven wearers of maxillary dentures were distributed into three groups and received different brushes: Oral B40, conventional toothbrush (Oral B); Denture, denture-specific brush (Condor); Johnson & Johnson, denture-specific brush (Johnson & Johnson). The 60-day experimental period was divided into two techniques: I - brushing (brush associated with a paste - Dentu Creme, Dentco) three times a day; II - brushing and daily application of 1% neutral red on the denture internal surface. Biofilm quantification was carried out weekly and the areas with dye biofilm were obtained by means of Image Tool 2.02 software. Results: Biofilm removal was more effective during Technique II (Wilcoxon test: p=0.01) for the three groups of brushes. When the brushes were compared in Technique I, the Kruskal Wallis test indicated statistical difference between Denture X Johnson & Johnson and Denture X Oral B40, in which the Denture was more efficient. For Technique II, there was no statistical difference between brushes (p>0.05). Conclusion: The disclosed application promoted more efficacy on biofilm removal, regardless of the brush used. Denture (Condor) was more efficient than the other brushes during Technique I. PMID:19089247

  7. 42 CFR 440.120 - Prescribed drugs, dentures, prosthetic devices, and eyeglasses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...false Prescribed drugs, dentures, prosthetic devices, and eyeglasses. 440.120...120 Prescribed drugs, dentures, prosthetic devices, and eyeglasses. (a...or partial set of teeth. (c) “Prosthetic devices” means replacement,...

  8. 42 CFR 440.120 - Prescribed drugs, dentures, prosthetic devices, and eyeglasses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...false Prescribed drugs, dentures, prosthetic devices, and eyeglasses. 440.120...120 Prescribed drugs, dentures, prosthetic devices, and eyeglasses. (a...or partial set of teeth. (c) “Prosthetic devices” means replacement,...

  9. 42 CFR 440.120 - Prescribed drugs, dentures, prosthetic devices, and eyeglasses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...false Prescribed drugs, dentures, prosthetic devices, and eyeglasses. 440.120...120 Prescribed drugs, dentures, prosthetic devices, and eyeglasses. (a...or partial set of teeth. (c) “Prosthetic devices” means replacement,...

  10. 42 CFR 440.120 - Prescribed drugs, dentures, prosthetic devices, and eyeglasses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...false Prescribed drugs, dentures, prosthetic devices, and eyeglasses. 440.120...120 Prescribed drugs, dentures, prosthetic devices, and eyeglasses. (a...or partial set of teeth. (c) “Prosthetic devices” means replacement,...

  11. 42 CFR 440.120 - Prescribed drugs, dentures, prosthetic devices, and eyeglasses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...false Prescribed drugs, dentures, prosthetic devices, and eyeglasses. 440.120...120 Prescribed drugs, dentures, prosthetic devices, and eyeglasses. (a...or partial set of teeth. (c) “Prosthetic devices” means replacement,...

  12. The role of friction in the mechanism of retaining the partial removable dentures with double crown system.

    PubMed

    D?browa, Tomasz; Dobrowolska, Anna; Wieleba, Wojciech

    2013-01-01

    Cylindrical telescopic crowns belong to bolt dentures, because their adhesion strength is based on the friction force. The magnitude of static and slide friction forces depends on the strain within the contact area and properties of materials employed. Friction force value between telescope elements declines in the first phase of wearing period and, subsequently, maintains particular constant value of 8 to 10 N. In the telescopic technique, homo and heterogenic joints are used. The following prosthodontic materials have been examined: goldbase alloys (Degudent Kiss, Degulor M), cobalt-base alloy (Brealloy 270), ceramics (Zircon Oxide, Zirconia) during tribological investigations on FGP composite resin. The cooperating surfaces were moistened with synthetic saliva. The research confirmed the dependence of the static friction coefficient on the contact pressure for the analyzed pairs of materials used in prosthodontics. The biggest effect of the contact pressure on the coefficient of friction value occurs when the ceramic rubs on FGP composite resin. The most stable friction coefficient in the context of contact pressure changes as well as life has been found in the case of the cobalt alloy Brealloy 270. An interesting material is a gold alloy Degulor M, for which the coefficient of friction varies only slightly with pressure in the range of 0.6 to 0.9 MPa. PMID:24479667

  13. A clinical study to assess the breath protection efficacy of denture adhesive.

    PubMed

    Myatt, Graham J; Hunt, Sheri A; Barlow, Ashley P; Winston, J Leslie; Bordas, Alice; El Maaytah, Mohammed

    2002-11-15

    This randomized and controlled, examiner-blind, 3-period, crossover clinical trial was designed to determine the effect of an experimental denture adhesive, a marketed denture adhesive (European Fixodent( Fresh), or no denture adhesive on the breath odor of 37 adults wearing full maxillary and mandibular dentures. Breath quality was measured at baseline and at 3 and 6 hours after the start of each treatment period via monitoring of volatile sulfur compounds (VSCs) using a halimeter and second-person organoleptic grading. A 48-hour washout phase separated treatment periods. There were no statistically significant differences in VSCs between any of the treatment regimens over 6 hours. Both the denture adhesive treatments were superior in breath quality improvement in organoleptic scores compared to no denture adhesive at 3 and 6 hours (p=0.0001). This research demonstrates the ability of both an experimental and marketed denture adhesive to deliver superior second-person breath benefits relative to no adhesive. The results indicate that Fixodent denture adhesives provide the denture wearer with a noticeable improvement in breath. PMID:12444398

  14. Evaluation of awareness and knowledge about denture cleansers among dental professionals.

    PubMed

    Pasricha, Neeta; Sidana, Venus

    2014-12-01

    Denture cleansers have been widely used in prosthodontics for cleaning and maintaining dentures. However, little is known about dentist's knowledge, awareness and experience of denture cleansers. Denture wearers would benefit greatly from a dental professional's guidance regarding use of dental cleansers. Basic objective of this study is to investigate awareness and knowledge about denture cleansers among dental professionals. A quota sampling technique was adopted with a sample size of 200 respondents. A well-structured questionnaire was used for collection of cross-sectional data. Statistical analyses were adopted to draw logical and scientific inferences. The ? (2) test was used to test the independence of various attributes. Highest number of respondents (55.5 %) used tablet form of denture cleanser. 47.5 % reported that they had little knowledge about adverse effects of denture cleansers. A significant percentage (36 %) reported that no knowledge is imparted about denture cleansers in their curriculum. Eighty seven percent of respondents felt the need to enhance their knowledge. It is inferred from the present study that it is very important to raise dentist's awareness and knowledge about denture cleansers by teaching them in more depth and further in continuing education and training, so as to enable them to impart adequate guidance to their patients. PMID:25489164

  15. A survey assessing modes of maintaining denture hygiene among elderly patients

    PubMed Central

    Saha, Ashishtaru; Dutta, Sudipto; Varghese, Rana K.; Kharsan, Vinay; Agrawal, Anil

    2014-01-01

    Objective: To determine the denture hygiene habits in complete denture wearers. Materials and Methods: In this study, a self-administered structured questionnaire was developed to know the attitude of the patients from the Department of Prosthodontics regarding denture hygiene. The study sample consisted of totally 500 subjects, which included 284 (56.8%) males and 216 (43.2%) females. Data were analyzed using SPSS version 15.0 with Chi-square (?2) test at P < 0.05. Results: Nearly half of the subjects cleaned their dentures daily once. Participants from the younger age group and who had been wearing dentures since 2 years maintained better frequency of cleaning. The majority of these subjects used water and brush for denture cleansing. After seeing the condition, more than half of the dentures were rated as poor (60%). There was significant difference between all the groups on comparison (P = 0.001). Conclusion: Poor condition of complete dentures seen in the population is mainly due to irregular cleansing habits and also less usage of cleansing solutions. Dentists should give proper instructions regarding maintenance of denture hygiene. PMID:25374830

  16. Zirconia-based dental crown to support a removable partial denture: a three-dimensional finite element analysis using contact elements and micro-CT data.

    PubMed

    Rocha, Eduardo Passos; Anchieta, Rodolfo Bruniera; de Almeida, Erika Oliveira; Freitas, Amilcar Chagas; Martini, Ana Paula; Sotto-Maior, Bruno Sales; Luersen, Marco Antonio; Ko, Ching Chang

    2015-12-01

    Veneer fracture is the most common complication in zirconia-based restorations. The aim of this study was to evaluate the mechanical behavior of a zirconia-based crown in a lower canine tooth supporting removable partial denture (RPD) prosthesis, varying the bond quality of the veneer/coping interface. Microtomography (?CT) data of an extracted left lower canine were used to build the finite element model (M) varying the core material (gold core - MAu; zirconia core - MZi) and the quality of the veneer/core interface (complete bonded - MZi; incomplete bonded - MZi-NL). The incomplete bonding condition was only applied for zirconia coping by using contact elements (Target/Contact) with 0.3 frictional coefficients. Stress fields were obtained using Ansys Workbench 10.0. The loading condition (L = 1 N) was vertically applied at the base of the RPD prosthesis metallic support towards the dental apex. Maximum principal (?max) and von Mises equivalent (?vM) stresses were obtained. The ?max (MPa) for the bonded condition was similar between gold and zirconia cores (MAu, 0.42; MZi, 0.40). The incomplete bonded condition (MZi-NL) raised ?max in the veneer up to 800% (3.23 MPa) in contrast to the bonded condition. The peak of ?vM increased up to 270% in the MZi-NL. The incomplete bond condition increasing the stress in the veneer/zirconia interface. PMID:25331825

  17. Implant-Supported Denture

    MedlinePLUS

    ... implants for support. Bar-retained dentures — A thin metal bar that follows the curve of your jaw ... dentures) — Each implant in the jawbone holds a metal attachment that fits into another attachment on the ...

  18. Prevalence of mutans streptococci isolated from complete dentures and their susceptibility to mouthrinses.

    PubMed

    André, Rodrigo Fernando Gonçalves; Andrade, Ingrid Machado de; Silva-Lovato, Cláudia Helena; Paranhos, Helena de Freitas Oliveira; Pimenta, Fabiana Cristina; Ito, Izabel Yoko

    2011-01-01

    The aims of this study were to evaluate the incidence of mutans streptococci (MS - sessile form) on complete maxillary dentures after use of a specific denture paste, and to determine the minimum inhibitory concentration (MIC) and maximum inhibitory dilution (MID) of 3 oral mouthrinses: Cepacol, Plax and Periogard. Seventy-seven complete denture wearers were randomly assigned into 2 groups, according to the product used for denture cleaning: Control group - conventional dentifrice (Kolynos-Super White); and Test group: experimental denture cleaning paste. Denture biofilm was collected at baseline and after 90 and 180 days after treatment by brushing the dentures with saline solution. After decimal serial dilution, samples were seeded onto agar sucrose bacitracin to count colonies with morphological characteristics of MS. MS identification was performed by the sugar fermentation tests. After this procedure, brain heart infusion broth (BHI) was added to oral mouthrinses (Plax, Cepacol e Periogard) and seeded on Petri dishes. The colonies were seeded using the Steers multiplier and, after the incubation, the MIC and MID of the mouthrinses were calculated. The results showed an incidence of 74.0% (n=57) of MS in the 77 complete dentures examined in the study, being 76.3% (n=29) of the Control group (conventional dentifrice) and 71.8% (28) of the Test group (experimental denture cleaning paste). In both groups, the number of positive cases for MS decreased from day 0 to day 180. In the Test group there was a slight decrease in the incidence of Streptococcus mutans 90 days after use of the experimental denture cleaning paste, which was not observed in the Control group. As regards to mouthrinses, for both groups, Periogard showed antimicrobial action with the highest dilution, followed by Cepacol and Plax. In conclusion, the incidence of MS in complete dentures was high and Periogard was the mouthrinse with the strongest antimicrobial action against MS. The experimental denture cleaning paste showed a slight action against S. mutans after 90 days of treatment. PMID:21519651

  19. Comparison of castability and surface roughness of commercially pure titanium and cobalt-chromium denture frameworks

    Microsoft Academic Search

    Kyung-Soo Jang; Suk-Jin Youn; Yung-Soo Kim

    2001-01-01

    Statement of problem. Titanium is a biocompatible material, but it is not widely used in clinical dentistry for conventional removable denture frameworks. Little research exists on its applicability. Purpose. This study compared the casting accuracy and roughness of titanium and cobalt-chromium denture frameworks. Material and methods. Twenty Kennedy Class II, Division 1 removable partial denture frameworks were fabricated with commercially

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

    PubMed

    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. PMID:23101181

  1. ACANTHAMOEBA GUIDANCE DOCUMENT FOR CONTACT LENS WEARERS

    EPA Science Inventory

    The document reviews the risk of Acanthamoeba Keratitis for contact lens wearers. The document also reviews Granulomatous Amebic Encephalitis, another disease associated with Acanthamoeba in immune compromised individuals. Reports indicate that keratitis due to Acanthamoeba is a ...

  2. Effect of dentist's clinical experience on treatment satisfaction of a complete denture.

    PubMed

    Kimoto, S; Kimoto, K; Kitamura, A; Saita, M; Iijima, M; Kawai, Y

    2013-12-01

    The relationship between the prosthodontic experience of dentists and satisfaction of complete denture wearers remains unknown. To investigate whether a prosthodontist's clinical experience affects treatment satisfaction of a complete denture wearer. From April 2004 to July 2006, we conducted a randomised controlled trial at two centres, including 74 edentulous patients; of these, 32 and 30 were randomly allocated to the ED or ID group, respectively. All the patients rated their satisfaction with dentures, including general satisfaction and satisfaction of chewing ability, speaking, cleaning, stability, retention, comfort and aesthetics. These satisfaction ratings were measured by a 100-mm visual analog scale (VAS). Perceived chewing ability to foods, divided into five grades, was measured using a questionnaire. The mastication index (MI) was calculated for each grade. General satisfaction and satisfaction of speaking, stability and retention were significantly higher in the ED than in the ID group (P = 0·049, 0·003, 0·019 and 0·041, respectively). No significant difference existed between the MI of the ED (71·3 ± 18·4) and ID group (64·1 ± 16·53). However, the perceived chewing ability of grade 5 food, whose texture was the hardest among all the grades, was significantly higher in the ED group than in the ID group. Within its limitations, this study showed that a clinician's prosthodontic experience affects a complete denture wearer's satisfaction ratings. PMID:24237360

  3. Denture impaction in the oesophagus experience of a young ENT practice in Nigeria

    PubMed Central

    Adedeji, Taiwo Olugbemiga; Olaosun, Adedayo Olugbenga; Sogebi, Olusola Ayodele; Tobih, James E

    2014-01-01

    Introduction The effect of dental loss and associated desire to restore its function and aesthesis has led to an increase in the number of people wearing dentures. This study therefore reviews the cases of impacted acrylic dentures in the oesophagus. Methods A retrospective review of patients that were managed for oesophageal denture impaction at Ladoke Akintola University of Technology Teaching Hospital, Osogbo, Osun State, Nigeria, over an eight year period from 2005 to 2012. Results A total of 14 patients (M: F 2.5: 1). The age ranged from 32 - 75 years. Majority 64.3%) were 51 years and above. Over 70% presented early. Major presenting symptoms were throat pain (100%), odynophageal (92.9%) and dysphageal (78.6%). The radiographic findings were air entrapment (64.3%) and increase in prevertebral soft tissue shadow (78.6%). Majority (87.5%) were impacted at the upper (cervical) oesophagus. Over 78% had successful extraction with rigid oesophagoscopy. Two (14.3%) had spontaneous expulsion of the denture and 1 (7.1%) discharged himself against medical advice. Complications were mucosa tear (28.6%), laryngeal spasm/ airway obstruction (14.3%), mucosa oedema/ erythema (57.1%), neck abscess (7.1%). Conclusion Impaction of esophageal dentures is relatively common in our locality; most patients present early for medical attention and associated with successful rigid oesophagoscopies and denture extraction under GA, and generally good outcome. Education of the wearers of dentures was emphasized as a way of preventing dentures impaction. PMID:25478051

  4. Effect of Denture-Related Stomatitis Fluconazole Treatment on Oral Candida albicans Susceptibility Profile and Genotypic Variability

    PubMed Central

    Figueiral, Maria Helena; Fonseca, Patrícia; Lopes, Maria Manuel; Pinto, Eugénia; Pereira-Leite, Teresa; Sampaio-Maia, Benedita

    2015-01-01

    Denture-related stomatitis (DRS) is the most common condition affecting removable-denture wearers, and Candida albicans the most frequent pathogenic agent. Systemic antifungal treatment is indicated but recurrences are frequent. The aim of this study was to characterize the oral load, fluconazole susceptibility profile and genotypic variability of oral C. albicans isolates from patients with DRS before (T0), immediately after fluconazole treatment (Tat) and after 6-months follow-up (T6m). Eighteen patients presenting DRS and treated with fluconazole were followed at the Faculty of Dentistry of Oporto University. Seventy C. albicans isolates were obtained and identified using standard cultural and biochemical multi-testing. Fluconazole susceptibility was tested by E-test®. Microsatellite-primed PCR was performed to assess the genotypic variability of C. albicans isolates. The patients’ mean age was 58.0±3.2 years, and 55.6%/44.4% had total/partial dentures. Before treatment, 22.2%, 44.4% and 33.3% of the patients presented DRS type I, II or III, respectively. Fluconazole treatment healed or improved DRS in 77.8% of the patients, accompanied by an 83.5% reduction in oral C. albicans load. However, after 6-months, oral C. albicans load increased significantly and DRS severity was similar to the one observed before treatment. Moreover, the prevalence of patients presenting fluconazole resistant isolates of C. albicans increased significantly throughout the study: T0-5.6%, Tat-10.0% and T6m-42.9%. A change in the genotypic variability of C. albicans isolates was also verified, being mostly associated to fluconazole susceptibility profile change. In conclusion, fluconazole presents a good short-term DRS treatment efficiency, but may be associated to a long-term emergence of C. albicans fluconazole resistance. PMID:25674171

  5. On denture marking.

    PubMed

    Borrman, H I; DiZinno, J A; Wasén, J; René, N

    1999-06-01

    During the last decades in Sweden dentures have been permanently marked with a stainless steel metal band incorporated into the acrylic and containing the patient's birth date, a special number, and "S" for Sweden. The last recommendation issued by the National Board of Health and Welfare states that "the patients shall always be offered denture marking and be informed about the benefit thereof. Denture marking is not permitted if the patient refuses it". Requirements for denture markers have been that they should be biologically inert (when incorporated into the denture), not be expensive, be easy to inscribe, be possible to retrieve after an accident, and survive elevated temperatures for a reasonable time under normal circumstances. Although the frequency of edentulousness has decreased in recent years due to the improvement in oral health there remains a need to address the issue of marking of complete dentures, because there is a large variation in the oral status of populations in different countries. Given that only one marked denture can reveal the identity of a deceased person when all other methods fail to do so, makes it worthwhile. Furthermore, denture marking is important in long-term care facilities. We have investigated the issue of denture marking in Europe and in the United States. The results from the European survey show that denture marking is, to our knowledge regulated by law only in Sweden and Iceland. In the US denture marking is so far mandatory in 21 states while New York State requires dentures to be marked if the patient requests it and several other states impose the obligation to mark dentures on long-term care facilities. Since there is no international consensus regarding the issue of denture marking it is important to address it. A survey from the Nordic countries has shown that if denture marking was in general use, the contribution to the establishment of identity by forensic odontology in cases of fire would increase by about 10%. This means that about 25 more individuals could have been identified if their dentures were marked. Increased international collaboration is needed to solve the issue of denture marking for clinical and forensic purposes. PMID:10709559

  6. Metal-ceramic screw-retained implant fixed partial denture with intraoral luted framework to improve passive fit.

    PubMed

    Baig, Mirza Rustum; Gunaseelan, Rajan

    2012-04-01

    Passive fit of a long-span screw-retained implant prosthesis is an important criteria for the success of the restoration. This article describes a technique for fabricating a ceramometal implant fixed dental prosthesis (FDP) for a long-span partially edentulous situation by altering the conventional screw-retained design. The possibility of a passive fit is maximized by intraoral luting of the cast frame to milled abutments, and the potential framework distortion during fabrication is compensated to a major extent. Retrievability is ensured by screw retention of the prosthesis to the implants. Compared with conventional porcelain fused to metal screw-retained FDP, this prosthesis is relatively inexpensive to fabricate. PMID:20932151

  7. [Zirconia and removable partial dentures].

    PubMed

    Rösch, Rolf; Mericske-Stern, Regina

    2008-01-01

    The present paper deals with the double crown technique in removable prosthodontics. New ceramic materials like zirconia are increasingly used in combination with CAD/CAM technologies for framework fabrication of fixed prosthesis, tooth- or implant-supported. However, zirconia is also a newly accepted material in removable prosthodontics. It replaces gold alloys for the fabrication of primary telescopic crowns. The Galvanoforming technology is preferably used to fabricate the secondary crowns. The combination of both techniques and materials results in a prosthetic reconstruction of high quality, optimum fit and good biocompatibility. PMID:18998581

  8. Prosthodontic management of flat mandibular ridge by mini implant supported over denture.

    PubMed

    Garhnayak, Mirna; Garhnayak, Lokanath; Dev, Shruti; Kar, Aswini Kumar; Mohapatra, Abhijita

    2014-07-01

    Loosening of lower denture has always been a common complaint of denture wearer, particularly in case of severe bone resorption. Various treatment modalities including preprosthetic surgery or ridge augmentation therapy to improve the ridge height and conventional implant treatments are available. But many patients are not willing to undergo through such extensive surgical procedure or conventional twin stage implant therapy owing to the chronic old age ailment and cost factor. So mini implant (SENDAX MDI) supported over denture is a boon for them who want a quick and minimally invasive solution, with a much lower cost. In this article we shall discuss the case report of a 60-year-old female patient with atropic mandibular ridge rehabilitated with MDI, (mini dental implant), Sendax mini implant. PMID:25177653

  9. Prosthodontic Management of Flat Mandibular Ridge by Mini Implant Supported Over Denture

    PubMed Central

    Garhnayak, Lokanath; Dev, Shruti; Kar, Aswini Kumar; Mohapatra, Abhijita

    2014-01-01

    Loosening of lower denture has always been a common complaint of denture wearer, particularly in case of severe bone resorption. Various treatment modalities including preprosthetic surgery or ridge augmentation therapy to improve the ridge height and conventional implant treatments are available. But many patients are not willing to undergo through such extensive surgical procedure or conventional twin stage implant therapy owing to the chronic old age ailment and cost factor. So mini implant (SENDAX MDI) supported over denture is a boon for them who want a quick and minimally invasive solution, with a much lower cost. In this article we shall discuss the case report of a 60-year-old female patient with atropic mandibular ridge rehabilitated with MDI, (mini dental implant), Sendax mini implant. PMID:25177653

  10. Antifungal activity, biofilm-controlling effect, and biocompatibility of poly(N-vinyl-2-pyrrolidinone)-grafted denture materials

    PubMed Central

    Sun, Xinbo; Cao, Zhengbing; Yeh, Chih-Ko; Sun, Yuyu

    2013-01-01

    Colonization and biofilm-formation of Candida species on denture surfaces cause Candida-associated denture stomatitis (CADS), a common, recurring disease affecting up to 67% of denture wearers. We developed poly(N-vinyl-2-pyrrolidinone)-grafted denture materials that can be repeatedly recharged with various antifungal drugs to achieve long-term antifungal and biofilm-controlling effects. The monomer, N-vinyl-2-pyrrolidinone (NVP), was grafted onto poly(methyl methacrylate) denture resins through plasma-initiated grafting polymerization. The physical properties and biocompatibility of the resulting resins were not negatively affected by the presence of up to 7.92% of grafted poly (N-vinyl-2-pyrrolidinone) (PNVP). Miconazole and chlorhexidine digluconate (CD) were used as model antifungal drugs. PNVP grafting significantly increased the drug absorption capability of the resulting denture materials. Further, the new materials showed sustained drug release and provided antifungal effects for weeks (in the case of CD) to months (in the case of miconazole). The drug-depleted resins could be recharged with the same or a different class of antifungal drug to further extend antifungal duration. If needed, drugs on the PNVP-grafted denture materials could be “washed out” (quenched) by treating with PNVP aqueous solutions to stop drug release. These results point to great potentials of the new materials in controlling biofilm-formation in a wide range of device-related applications. PMID:23708753

  11. Compliance among soft contact lens wearers.

    PubMed

    Kuzman, Tomislav; Kutija, Marija Barisi?; Masnec, Sanja; Jandrokovi?, Sonja; Mrazovac, Danijela; Jurisi?, Darija; Skegro, Ivan; Kalauz, Miro; Kordi?, Rajko

    2014-12-01

    Contact lens compliance is proven to be crucial for preventing lens wear-related complications because of the interdependence of the steps in lens care regime and their influence on lens system microbial contamination. Awareness of the patients' lens handling compliance as well as correct recognition of non-compliant behaviours is the basis for creating more targeted strategies for patient education. The aim of this study was to investigate compliance among soft contact lens (SCL) wearers in different aspects of lens care handling and wearing habits. In our research 50 asymptomatic lens wearers filled out a questionnaire containing demographic data, lens type, hygiene and wearing habits, lenses and lens care system replacement schedule and self-evaluation of contact lens handling hygiene. We established criteria of compliance according to available manufacturer's recommendations, prior literature and our clinical experience. Only 2 (4%) of patients were fully compliant SCL wearers. The most common non-compliant behaviours were insufficient lens solution soaking time (62%), followed by failure to daily exchange lens case solution and showering while wearing lenses. 44% of patients reported storing lenses in saline solution. Mean lens storage case replacement was 3.6 months, with up to 78% patients replacing lens case at least once in 3 months. Average grade in self evaluating level of compliance was very good (4 +/- 0.78) (from 1-poor level of hygiene to 5-great level of hygiene). Lens wearers who reported excessive daily lens wear and more than 10 years of lens wearing experience were also found to be less compliant with other lens system care procedures. (t = -2.99, df=47, p < 0.0045 and t = -2.33, df= 48, p < 0.024, respectively). Our study indicates that almost all patients had some degree of non-compliance in lens system maintenance steps. Most common non-compliant behaviours were the ones that are crucial for maintaining lens sterility and preventing infection. Despite the low objective compliance rate, self grading was relatively high. Therefore, these results indicate the need for patient education and encouragement of better lens wearing habits and all of the lens maintenance steps at each patient visit. PMID:25842762

  12. Side effects of immersion-type cleansers on the metal components of dentures.

    PubMed

    Backenstose, W M; Wells, J G

    1977-06-01

    Three metals were immersed in eight denture cleansing solutions for a period of 240 hours to determine the relative side effects of these cleansers upon various metal components of complete and removable partial dentures. Conclusions drawn from this study are: 1. Commercial bleaches and unbuffered hypochlorite solutions should not be used on dentures with metal components. 2. Routine use of buffered hypochlorite solutions may cause surface damage to aluminum-base material. 3. Stainless steel (orthodontic wire) will tarnish after continued exposure to buffered and unbuffered hypochlorite solutions. 4. Further research is necessary to delineate the effects of existing denture cleansers and to improve on their effectiveness and safety. PMID:194029

  13. Inhibiting microbial adhesion to denture base acrylic resin by titanium dioxide coating.

    PubMed

    Arai, T; Ueda, T; Sugiyama, T; Sakurai, K

    2009-12-01

    Mechanical cleaning of dentures is effective in preventing infections such as aspiration pneumonia and denture stomatitis. For denture wearers with a physical handicap and the elderly, however, mechanical cleaning can present problems. The aim of this study was to investigate the effect of coating denture base acrylic resin with titanium dioxide (TiO(2)) in the inhibition of oral microbial adhesion. We prepared uniformly sized acrylic resin plates (10 mm x 10 mm x 0.5 mm), which were divided into two groups (a non-coated group and a TiO(2)-coated group). The plates were immersed in cultured Streptococcus sanguinis or Candida albicans and incubated for 24 h. After incubation, each plate was washed to remove loosely adherent microorganisms, and then incubated for a further 24 h. Adenosine triphosphate (ATP) content of the microorganisms was evaluated using a reagent containing benzalkonium, which extracts intra-cellular ATP. In addition, to determine biofilm formation, we also observed each plate by scanning electron microscopy (SEM). We found that the ATP content of both S. sanguinis and C. albicans was reduced by the TiO(2) coating (P = 0.000). Observation by SEM confirmed that the TiO(2) coating inhibited biofilm formation. The results indicate that a TiO(2) coating on a denture base acrylic resin inhibits adhesion of S. sanguinis and C. albicans. PMID:19941590

  14. The denture box. An aid to denture hygiene.

    PubMed

    Faigenblum, M J

    2015-01-01

    This paper re-visits the need for patients or their carers to maintain as low a level of denture biofilm as possible. It notes that the handling of dentures is unpleasant to carers and suggests a method of reducing this contact to a minimum but yet allow efficient cleaning by means of brushing. It also highlights the potential damage that can occur due to mishandling or accident. The denture box acts as a safe storage unit and finally, it suggests that its 'footprint' allows accurate recovery in an institution where dentures can be inadvertently mingled. PMID:25571813

  15. Efficacy of denture cleansers on denture liners contaminated with Candida species

    Microsoft Academic Search

    Maria Áurea Feitosa Ferreira; Tatiana Pereira-Cenci; Lucíola Maria Rodrigues de Vasconcelos; Renata Cunha Matheus Rodrigues-Garcia; Altair Antoninha Del Bel Cury

    2009-01-01

    As poor denture hygiene is related to Candida colonisation, disinfectant solutions have been proposed as an effective method of preventing denture stomatitis. This study\\u000a assessed the efficacy of denture cleansers on Candida albicans and Candida glabrata adherence on denture liners. Another aim was to correlate materials’ surface roughness (Ra) to Candida adherence. Specimens of three denture liners (soft and hard

  16. Cytotoxicity of denture adhesives

    Microsoft Academic Search

    Pedro Sousa de Gomes; Maria Helena Figueiral; Maria Helena R. Fernandes; Crispian Scully

    Ten commercially available denture adhesives, nine soluble formulations (six creams, three powders) and one insoluble product\\u000a (pad), were analyzed regarding the cytotoxicity profile in direct and indirect assays using L929 fibroblast cells. In the\\u000a direct assay, fibroblasts were seeded over the surface of a thick adhesive gel (5%, creams; 2.5%, powders and pad). In the\\u000a indirect assay, cells were cultured

  17. Changes in patient satisfaction and masticatory efficiency during adaptation to new dentures.

    PubMed

    Farias-Neto, Arcelino; Carreiro, Adriana da Fonte Porto

    2015-03-01

    Because adapting to new conventional dentures is highly variable, there is uncertainty as to how long dissatisfied patients should wait before choosing a treatment with dental implants. The authors investigated whether changes in patient satisfaction and masticatory efficiency may be observed between 3 and 6 months after the insertion of new conventional complete dentures. The study included 24 edentulous patients requiring new complete dentures. Masticatory efficiency and patient satisfaction were evaluated at 3 and 6 months post-insertion. Masticatory efficiency was evaluated through the colorimetric method, with the beads as the artificial test food. A method for quantifying overall satisfaction of complete-denture wearers was used. Subjects were asked to respond to questions with three-grade answers concerning 12 factors: chewing, tasting, speech, esthetics, pain, fit, retention, and comfort (maxillary and mandibular evaluations were done for each of the last four factors). The results of patient satisfaction and masticatory efficiency at 3 and 6 months post-insertion were compared using the paired-samples t test (? = 0.05). Significant reductions in mandibular pain (P less than 0.05) and improvements in mandibular fit (P less than 0.05) were observed at 6 months. No difference was found for patient overall satisfaction, chewing, tasting, speech, maxillary pain, esthetics, maxillary fit, retention, comfort, and masticatory efficiency. The authors concluded that reduction in pain and improvements in adaptation of the lower denture may be observed between 3 and 6 months after insertion of new conventional complete dentures. This period of adaptation should be considered before choosing a treatment with dental implants. PMID:25822743

  18. Evaluation of an electrosonic denture cleaner.

    PubMed

    Muenchinger, F S

    1975-06-01

    The effectiveness of an electrosonic denture cleansing system and a commercially available denture soaking agent was studies. An experimental sample of 32 edentulous patients was evaluated for presence of plaque and calculus on their dentures before and after the introduction of two different cleaning methods. Comparisons of plaque scores between test dentures and control dentures indicated that all the methods studies were equally effective in the prevention of plaque and accretions, yet no method eliminated plaque or calculus accumulation. PMID:1056470

  19. [Clinical, microbiological and immunological findings in peri-implantitis patients with bar-retained lower removable partial dentures, compared to a healthy control group (12-month-follow-up)].

    PubMed

    Mesmer, Christian; Forster, András; Antal, Márk; Nagy, Katalin

    2012-06-01

    Cause, treatment strategies and prognosis of peri-implantitis is not well understood. The aim of this study was to followup clinical, microbiological and immunological findings in individuals wearing bar-retained lower partial dentures with and without peri-implantitis, pre and post treatment. From the Tuebingen Implant Registry recall program 16 peri-implantitis patients were compared to 16 healthy individuals in a prospective, unblinded study. Peri-implantitis was treated with a single anti-inflammatory therapy according to the CIST protocol while the controls received professional implant cleaning. The following findings were recorded at four time points before treatment (T1) and 30, 90, 360 days post treatment (T2-T4): sulcular fluid flow rate, probing depth, plaque and bleeding index, implant stability (Periotest); sulcular concentrations of interleukin-1 beta, plasminogen activator inhibitor 2, prostaglandin E2, and the sum score of five periodonto-pathogenic bacteria species by PCR (Hain Microldent test). Statistically significant differences between healthy and diseased implants were found for probing depth, bleeding on probing, bacterial load, and implant stability. For the first three, a significant decrease in severity was observed after treatment, but reached initial pre-treatment values within one year. No changes could be observed in the individuals without peri-implantitis. The results of the present study confirm marked differences in peri-implant findings between healthy and diseased sites. They demonstrate that a single anti-inflammatory intervention can initially--but not sustained--reduce probing depth, bleeding on probing, and the total bacterial load as evident from PCR diagnostics. Further immunological diagnostic measures do not seem to provide more information in the patients investigated. PMID:22826908

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

    PubMed Central

    Shetty, Mallika S.; Panchaml, Ganesh Shenoy; Shenoy, K. Kamalakanth

    2015-01-01

    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.

  1. Immunoglobulin Concentration in Tears of Contact Lens Wearers

    PubMed Central

    Maurya, Rajendra P.; Bhushan, Prashant; Singh, Virendra P.; Singh, Mahendra K.; Kumar, Prakash; Bhatia, Ravindra P.S.; Singh, Usha

    2014-01-01

    Purpose: To evaluate changes in the concentration of tear immunoglobulins in contact lens wearers. Methods: A total of 45 cases including 23 contact lens wearers (43 eyes) and 22 age and sex matched healthy controls having no ocular pathology were studied for immunoglobulins (IgA, IgG, IgM) in their tears by single radial immunodiffusion method. Results: Most of the cases used soft (56.6%) and semi-soft gas permeable (30.4%) contact lenses. Tear IgM was detected in only 17.4% and tear IgG in 43.6% of contact lens wearers, while in controls IgG was detected in 9.1% but none of the controls had IgM. There was a significant rise in total tear IgA (13.17 ± 4.44 mg/dl) in contact lens wearer as compared to controls (8.93 ± 3.79 mg/dl). Rise of tear IgA was more in symptomatic patients (15.38 ± 5.28 mg/dl) and in those wearing hard (19.73 ± 5.43 mg/dl) and semi-soft contact lenses (13.31 ± 5.43 mg/dl). A significant increase in tear IgA was noticed in subjects wearing lenses for >3 years (15.69 ± 5.39 mg/dl). About 43.4% of lens wearers were symptomatic and 80% of their lenses showed deposits and/or haziness. All cases with IgM in tear were symptomatic. Conclusion: The relation of immunoglobulin concentration with increasing duration of wear and material of contact lens shows that tear immunoglobulin rise accrues due to mechanical stimulation, hence contact lenses should not be used for a long period and lenses of hard nature should be discouraged. The maintenance, cleaning and deproteinization of the lenses are of high importance to avoid immunostimulation. PMID:25667732

  2. Differences in wearer response to garments for outdoor activity

    Microsoft Academic Search

    R. M. Laing; S. T. Sims; C. A. Wilson; B. E. Niven; N. M. Cruthers

    2008-01-01

    The performance of garments for outdoor activity was compared. Three fabrics, each in garments for the upper body, matched garment\\/wearer dimensions, were worn by 10 athletically ‘well-trained’ males under controlled conditions (hot 32 ± 2°C, 20 ± 2% relative humidity (RH); cold 8 ± 2°C, 40 ± 2% RH) with physical (instrumental) and sensory responses obtained during the trials. Differences in human responses to the fabrics\\/garments included heart

  3. Clinical and Histological Findings of Denture Stomatitis as Related to Intraoral Colonization Patterns of C. albicans, Salivary Flow, and Dry Mouth

    PubMed Central

    AlTarawneh, Sandra; Bencharit, Sompop; Mendoza, Luisito; Curran, Alice; Barrow, David; Barros, Silvana; Preisser, John; Loewy, Zvi G.; Gendreau, Linda; Offenbacher, Steven

    2012-01-01

    Purpose Multifactorial etiological factors contribute to denture stomatitis (DS), a type of oral candidiasis; however, unlike other oral candidiasis, DS can occur in a healthy person wearing a denture. In this study, we therefore attempt to explore the association between candida, denture, and mucosal tissue using 1) exfoliative cytology, 2) the candidal levels present in saliva, on mucosal tissues and on denture surfaces, and 3) the salivary flow rate and xerostomic symptoms. Materials and Methods A cross-sectional study enrolled 32 edentulous participants, 17 without DS as controls and 15 with DS (Newton’s classification type II and III). Participants with systemic or other known oral conditions were excluded. Participants completed a xerostomia questionnaire, and salivary flow rates were measured. Samples of unstimulated whole saliva (UWS) and stimulated whole saliva (SWS) were collected. UWS was used for fungal culturing. Periodic acid-Schiff (PAS) stain and quantitative exfoliative cytology were performed on samples from affected and unaffected mucosa from each participant. Levels of Candida species (albicans and non-albicans) were determined in salivary samples (expressed as colony-forming units, CFU), as well as from swab samples obtained from denture fitting surfaces, in addition to affected and unaffected mucosa. Results There were no significant differences in salivary flow rates, mucosal wetness, or frequency of reported dry mouth comparing participants with and without DS. Exfoliative cytology of mucosal smears demonstrated significantly higher (P = 0.02) inflammatory cell counts in DS patients, as compared with smears of healthy denture-wearers. C. albicans was significantly more prevalent in saliva (P = 0.03) and on denture surfaces (P = 0.002) of DS participants, whereas mucosal candidal counts and the presence of cytological hyphae did not show significant difference comparing DS to healthy participants. Conclusions In this investigation, we presented a unique group of healthy edentulous patients. This population may reflect the general DS population without systemic or other oral diseases. The prominent etiological factor for DS in this population is the presence of candida in denture and saliva. We found that other factors such as saliva flow/xerostomia, fitting of the denture, and the presence of candida in the mucosa, are less important in this population. Therefore, DS treatments in healthy patients should first focus on sanitization of an existing denture and/or fabrication of a new denture. PMID:23107189

  4. The conjunctival sensitivity in soft contact lens wearers.

    PubMed

    Igarashi, Tsutomu; Ono, Masafumi; Fujimoto, Chiaki; Suzuki, Hisaharu; Takahashi, Hiroshi

    2014-09-01

    We determined the influence of soft contact lenses (SCLs) on conjunctival sensitivity. A total of 26 volunteers (11 males, 15 females; mean age 28.3 ± 4.6 years; range 22-39 years) without dry eye were enrolled in the study. Subjects with a low corneal touch threshold, atopic keratoconjunctivitis, or vernal keratoconjunctivitis were excluded. In 26 participants, 12 were disposable SCL wearers. Touch thresholds were determined using a Cochet-Bonnet esthesiometer with a 0-60 mm nylon monofilament in 5 mm increments. The length (mm) was converted to tension (g/mm(2)). Mean touch sense thresholds in the SCL wearers (n = 12) and non-wearers (n = 14) were 10.7 ± 2.57 and 24.6 ± 7.3 g/mm(2) in the whole conjunctiva, and 9.07 ± 3.02 and 19.2 ± 7.8 g/mm(2) in the upper palpebral conjunctiva, respectively. Significant differences were observed in all locations (p < 0.01). The enhanced conjunctival sensitivity associated with SCL use may contribute to the dry eye-like symptoms in SCL users who do not have dry eye. PMID:25194462

  5. Problems Faced by Complete Denture-Wearing Elderly People Living in Jammu District

    PubMed Central

    Sharma, Sumeet; Singh, Sarbjeet; Wazir, Nikhil; Raina, Rajiv

    2014-01-01

    Context: Poor oral health is increasing dramatically among old people especially those living in rural and remote areas. Various factors such as low education background, low income, poor living conditions, unhealthy lifestyle, inadequate oral hygiene and tobacco use lead to poor oral health among older people which in turn lead to risks to their general health. The older people especially from rural areas are apprehensive about seeing a dentist and do not visit them regularly. This may lead to various problems which may have a detrimental influence on their quality of life. Aim: To know the problems faced by complete denture wearers in rural areas in Jammu district. Materials and Methods: Fifty patients from rural area Bishna, initially treated with a complete denture in the maxilla or mandibles were examined. The data were collected with the help of a questionnaire. Results: The results revealed that majority of respondents were in the age – group of 65-70 y. Majority of respondents complained of "difficulty chewing", "sore spots”, “painful and swollen gums". Majority of respondents had difficulty in speech, it was difficult for them to interact and communicate with their dentures on. Most of the respondents had lost confidence and had low self esteem. Clinical observations revealed that the commonest condition associated with denture wearing was Oral Stomatitis/ Burning mouth Syndrome, Superimposed infection and Angular cheilitis. Conclusion: Older people should Communicate and visit dentists, regularly, so that the dentists can adjust the treatment and pace according to their needs. Behavioural therapy techniques can make dental visits relatively anxiety and pain-free. PMID:25654025

  6. 21 CFR 872.3590 - Preformed plastic denture tooth.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Preformed plastic denture tooth. 872.3590 Section...Prosthetic Devices § 872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture tooth is a prefabricated...

  7. 21 CFR 872.3580 - Preformed gold denture tooth.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Preformed gold denture tooth. 872.3580 Section 872...Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth is a device composed of...

  8. 21 CFR 872.3580 - Preformed gold denture tooth.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Preformed gold denture tooth. 872.3580 Section 872...Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth is a device composed of...

  9. 21 CFR 872.3580 - Preformed gold denture tooth.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Preformed gold denture tooth. 872.3580 Section 872...Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth is a device composed of...

  10. 21 CFR 872.3590 - Preformed plastic denture tooth.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Preformed plastic denture tooth. 872.3590 Section...Prosthetic Devices § 872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture tooth is a prefabricated...

  11. Two-thirds of fixed partial prostheses (bridges) last 15 years

    Microsoft Academic Search

    N Creugars

    1998-01-01

    Objective To assess survival rates for fixed partial dentures and their abutments.Data sources Medline search 1966–1996 for studies reporting on the longevity of fixed partial dentures (FPD) (bridges, fixed partial dentures, crown & bridgework, survival and longevity). References of identified articles were also searched. Only articles in English were included and 35 were identified.Study selection Studies were included which contained

  12. A Novel Mechanism of Increased Infections in Contact Lens Wearers

    PubMed Central

    Gordon, Gabriel M.; Moradshahi, Navid; Jeong, Shinwu; Lane, Christianne

    2011-01-01

    Purpose. It is well documented that contact lens wearers have much higher incidences of corneal infections compared with those of non–contact lens wearers, although the exact cause(s) of this increased susceptibility has not been identified. A distinct subset of mucins (MUCs) is present on the ocular surface, acting to protect the integrity of the corneal epithelium. This study was performed to determine whether multipurpose contact lens solutions (MPCLSs) can cause increased infections in the cornea by destroying the protective cell-bound mucin layer. Methods. An immortalized human corneal limbal epithelial cell line was treated in the presence of four commonly used MPCLSs or PBS and the expression and release of MUC-16 was assessed. Cells were also cultured with Pseudomonas aeruginosa after MPCLS treatment and internalization of bacteria was assessed by quantitative genomic PCR. Loss of MUC-16 was then correlated with infection rates. Results. Each of the four commonly used MPCLSs examined in this study differentially affected mucin release. The relative effect was correlated with an increase in infection of corneal epithelial cells by P. aeruginosa. Conclusions. The results of this study are consistent with the hypothesis that MPCLSs cause increased infections in the cornea by destroying the protective cell-bound mucin layer. PMID:22039229

  13. Precision attachments for the partially dentate mouth

    PubMed Central

    Preiskel, H W

    1974-01-01

    Some uses of precision attachments in restoring the partially dentate mouth are considered. These devices are indicated where neither the clasp-retained denture nor the fixed bridge is entirely suitable. ImagesFig. 2 PMID:4614689

  14. Rechargeable Infection-responsive Antifungal Denture Materials

    PubMed Central

    Cao, Z.; Sun, X.; Yeh, C.-K.; Sun, Y.

    2010-01-01

    Candida-associated denture stomatitis (CADS) is a significant clinical concern. We developed rechargeable infection-responsive antifungal denture materials for potentially managing the disease. Polymethacrylic acid (PMAA) was covalently bound onto diurethane dimethacrylate denture resins in the curing step. The PMAA resins bound cationic antifungal drugs such as miconazole and chlorhexidine digluconate (CG) through ionic interactions. The anticandidal activities of the drug-containing PMAA-resin discs were sustained for a prolonged period of time (weeks and months). Drug release was much faster at acidic conditions (pH 5) than at pH 7. Drugs bound to the denture materials could be “washed out” by treatment with EDTA, and the drug-depleted resins could be recharged with the same or a different class of anticandidal drugs. These results suggest clinical potential of the newly developed antifungal denture materials in the management of CADS and other infectious conditions. PMID:20940361

  15. The impact of the National Denture Service on oral health-related quality of life among poor elders.

    PubMed

    Ha, J E; Heo, Y J; Jin, B H; Paik, D I; Bae, K H

    2012-08-01

    The objective of this study was to assess the effects of the Korean National Denture Service (NDS) for poor elderly people requiring dentures on oral health-related quality of life (OHRQOL). Data from follow-up studies were collected from 439 subjects at eight public health centres who answered every question of a questionnaire, and the OHRQOL was measured at the baseline and at 3-month follow-up after receiving the NDS according to the type of denture provision. The multivariate linear mixed model with a public health centre as a random effect for the score change of Oral Health Impact Profile (OHIP)-14K was carried out to confirm the factors related to the improvement in OHRQOL. The mean OHIP-14K was 28.60 at the baseline time points, and there was a decrease in the OHIP-14 scores to 21.14 ± 12.52 at the 3-month follow-up of the removable partial denture beneficiaries. The changes in OHIP-14K among complete denture beneficiaries were 21.53 ± 12.01 for previously dentate subjects and 22.54 ± 11.12 for edentate subjects. The multivariate linear mixed model of dentate subjects demonstrated that the improvement in the OHRQOL was associated with the number of remaining teeth, satisfaction with denture and self-reported oral health status after 3 months. In the case of the edentate model, satisfaction with denture was the only factor related to the improvement in OHRQOL. This study revealed considerable improvement in OHRQOL among poor elderly people after NDS. Satisfaction with provision of dentures was associated with improvement in the OHRQOL. PMID:22489919

  16. 21 CFR 872.3520 - OTC denture cleanser.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3520 OTC denture cleanser. (a) Identification...or paste that is intended to remove debris from removable prosthetic dental appliances, such as bridges or dentures. The...

  17. 21 CFR 872.3520 - OTC denture cleanser.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3520 OTC denture cleanser. (a) Identification...or paste that is intended to remove debris from removable prosthetic dental appliances, such as bridges or dentures. The...

  18. 21 CFR 872.3520 - OTC denture cleanser.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3520 OTC denture cleanser. (a) Identification...or paste that is intended to remove debris from removable prosthetic dental appliances, such as bridges or dentures. The...

  19. 21 CFR 872.3530 - Mechanical denture cleaner.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...AC-powered, that consists of a container for mechanically agitating a denture cleansing solution. The device is intended to clean a denture by submersion in the agitating cleansing solution in the container. (b) Classification. Class I...

  20. 21 CFR 872.3530 - Mechanical denture cleaner.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...AC-powered, that consists of a container for mechanically agitating a denture cleansing solution. The device is intended to clean a denture by submersion in the agitating cleansing solution in the container. (b) Classification. Class I...

  1. 21 CFR 872.3530 - Mechanical denture cleaner.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...AC-powered, that consists of a container for mechanically agitating a denture cleansing solution. The device is intended to clean a denture by submersion in the agitating cleansing solution in the container. (b) Classification. Class I...

  2. 21 CFR 872.3530 - Mechanical denture cleaner.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...AC-powered, that consists of a container for mechanically agitating a denture cleansing solution. The device is intended to clean a denture by submersion in the agitating cleansing solution in the container. (b) Classification. Class I...

  3. 21 CFR 872.3530 - Mechanical denture cleaner.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...AC-powered, that consists of a container for mechanically agitating a denture cleansing solution. The device is intended to clean a denture by submersion in the agitating cleansing solution in the container. (b) Classification. Class I...

  4. 21 CFR 872.3580 - Preformed gold denture tooth.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth...

  5. 21 CFR 872.3520 - OTC denture cleanser.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3520 OTC denture cleanser. (a) Identification...or paste that is intended to remove debris from removable prosthetic dental appliances, such as bridges or dentures. The...

  6. 21 CFR 872.3570 - OTC denture repair kit.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3570 OTC denture repair kit. (a) Identification. An OTC denture repair kit is a device...

  7. 21 CFR 872.3590 - Preformed plastic denture tooth.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture...

  8. 21 CFR 872.3590 - Preformed plastic denture tooth.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture...

  9. 21 CFR 872.3540 - OTC denture cushion or pad.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad. (a) Identification. An OTC denture cushion or pad is a...

  10. 21 CFR 872.3560 - OTC denture reliner.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3560 OTC denture reliner. (a) Identification. An OTC denture reliner is a device...

  11. 21 CFR 872.3540 - OTC denture cushion or pad.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad. (a) Identification. An OTC denture cushion or pad is a...

  12. 21 CFR 872.3590 - Preformed plastic denture tooth.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture...

  13. 21 CFR 872.3540 - OTC denture cushion or pad.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad. (a) Identification. An OTC denture cushion or pad is a...

  14. 21 CFR 872.3560 - OTC denture reliner.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3560 OTC denture reliner. (a) Identification. An OTC denture reliner is a device...

  15. 21 CFR 872.3580 - Preformed gold denture tooth.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth...

  16. 21 CFR 872.3520 - OTC denture cleanser.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3520 OTC denture cleanser. (a) Identification...or paste that is intended to remove debris from removable prosthetic dental appliances, such as bridges or dentures. The...

  17. Effect of incorporation of 2-tert-butylaminoethyl methacrylate on flexural strength of a denture base acrylic resin

    PubMed Central

    PALEARI, André Gustavo; MARRA, Juliê; PERO, Ana Carolina; RODRIGUEZ, Larissa Santana; RUVOLO-FILHO, Adhemar; COMPAGNONI, Marco Antonio

    2011-01-01

    Polymethyl methacrylate (PMMA) resins have commonly been used as a denture base material. However, denture bases may act as a reservoir for microorganisms and contribute to oral diseases in denture wearers. It is hypothesized that the 2-tertbutylaminoethyl methacrylate (TBAEMA) incorporated to acrylic resins should have antimicrobial activity related to the presence of amino groups on acrylic resin surface. Objectives The objectives of this study were to evaluate the presence of amino groups on acrylic resin surface and the influence on flexural strength after incorporation of TBAEMA. Material and Methods Six groups were divided according to the concentration of TBAEMA incorporated to acrylic resin (Lucitone 550): 0, 0.5, 1.0, 1.5, 1.75 and 2%. Specimens surface were evaluated by electron Spectroscopy for Chemical Analysis (ESCA) to detect the presence of amino groups, represented by nitrogen ratios. Flexural strength of the specimens was tested and results were analyzed by ANOVA and Tukey's test (?=0.05). Results Different nitrogen ratios were observed on specimen surfaces: 0, 0.13, 0.74, 0.66, 0.92 and 0.33% for groups 0, 0.5, 1.0, 1.5, 1.75, and 2%, respectively. Significant differences were found for flexural strength (p<0.001). The mean flexural strength values were 98.3±3.9, 93.3±3.2, 83.9±2.1, 82.8±5.2, 71.2±5.1 and 17.3±3.2 MPa for groups 0, 0.5, 1.0, 1.5, 1.75, and 2%, respectively. Conclusion Within the limitations of this study, the incorporation of TBAEMA results in the presence of the potentially antimicrobial amino groups on specimen surfaces, but affect the flexural strength, depending on the concentration of TBAEMA. PMID:21625732

  18. Resilient lining materials for dentures.

    PubMed

    Thomas, C J; Mori, T

    1993-01-01

    Modern resilient liners may be broadly classed as plasticized resins, silicone rubbers and fluoropolymers. Desirable properties would be pronounced softness and resiliency, or visco elasticity. Compression tests of Molloplast B (a silicone rubber), Kurepeet (a fluoropolymer), Visco-gel (a tissue conditioner) and Xantopren ( a silicon impression material) (as control) showed a displacement of 4% and recovery to 0.4% permanent deformation after 15s of loading for Molloplast and Xantopren, and up to 32% and 13% displacement respectively for Visco-gel and Kurepeet followed by considerable permanent deformation. Recovery of the latter showed a typical curve for visco-elasticity. The small amount of initial deformation of the elastic materials on the other hand indicated unyielding and consequently unsatisfactory properties. The deformation of Kurepeet was not as great as Visco-gel but the fact that it was visco-elastic meant that it was likely to be a suitable long-term lining material. It therefore complied with requirements that a resilient denture liner should be soft and visco-elastic. PMID:8695193

  19. [Complete removable dentures and prognathism].

    PubMed

    Postaire, M; Raux, D

    1991-06-01

    Further to some reminders concerning terminology and resorption, this article presents the full denture prosthetic treatment for two patients with total edentation and a prognathic malocclusion. The first case presents a tridimensional symptomatology, described by: a progeny; a voluminous mandibular terrain; a concave profile; a rather closed mandibular angle; a mandible ridge which circumscribes the upper jaw; The particularities of the prosthetic treatment in this case are: a lowering of the posterior occlusal plane; a mounting of the teeth in a limited external position, that is to say, the maxillary lingual cuspids and the mandibular mesio-distal groove on the inter-crest line; the mandibular incisors and cuspids placed with a lingual inclination to obtain an edge-to-edge occlusal contact. The second case is of vertical symptomatology type, described by: a macrogeny; a moderate concavity of the profile; a very marked increase of the vertical dimension; an open mandibular angle; a short ramus; a long mandibule; a very marked overjet between the anterior crests. The particularities of the prosthetic treatment for this case are: a posterior teeth placement, avoiding cross-bite position, taken into account the strong convergence of the intercrest lines; a strong lingual inclination of the mandibular incisors and cuspids, in order to obtain an edge-to-edge occlusal contact. In the light of these two specific cases, emphasis is placed on the particularities of the treatment and on the teeth placement proposed in order to avoid any cross-bite teeth mounting. PMID:1860077

  20. Fatigue test machine for denture base polymers.

    PubMed

    Stafford, G D; Lewis, T T

    1980-01-01

    A description of a single station fatigue test machine suitable for denture base polymers is given. This machine has been especially designed for dental purposes. A group of representative denture base polymers has been tested, which includes dental poly(methylmethacrylate) of the standard heat polymerized type, autopolymerizing pour type and a heat polymerized rubber graft polymer. These materials were compared and some preliminary results are given. These show that the rubber demonstrated the most satisfactory fatigue life and the pour types were least satisfactory. PMID:7470553

  1. Anticandidal efficacy of denture cleansing tablet, Triphala, Aloe vera, and Cashew leaf on complete dentures of institutionalized elderly.

    PubMed

    Shetty, Pooja J; Hegde, Vijaya; Gomes, Leslie

    2014-01-01

    With an increase in the number of dependent elderly, there is a need to introduce few natural products for denture cleansing, which are easily and economically available. Hence the aim of this study was to compare the anticandidal efficacy of denture cleansing tablet (sodium bicarbonate and sodium perborate monohydrate), Triphala (Phyllanthus emblica, Terminalia chebula and Terminalia belerica fruits powders in equal proportion), cashew leaf, Aloe vera and water (control) on complete dentures of institutionalized elderly. Study population consisted of 50 institutionalized elderly of Mangalore, Karnataka, with 10 in each group. Swabs were collected from the dentures before and after the use of denture cleansing tablet, Triphala, cashew leaf, Aloe vera, and water (control). Thereafter, the swabs were cultured on Sabouraud dextrose agar and the total candida counts were determined. Denture cleansing tablet and Triphala Churna showed a statistically significant reduction in Candida counts (P < 0.05). Denture cleansing tablet and Triphala Churna were found to be more effective. PMID:24812470

  2. Anticandidal efficacy of denture cleansing tablet, Triphala, Aloe vera, and Cashew leaf on complete dentures of institutionalized elderly

    PubMed Central

    Shetty, Pooja J.; Hegde, Vijaya; Gomes, Leslie

    2014-01-01

    With an increase in the number of dependent elderly, there is a need to introduce few natural products for denture cleansing, which are easily and economically available. Hence the aim of this study was to compare the anticandidal efficacy of denture cleansing tablet (sodium bicarbonate and sodium perborate monohydrate), Triphala (Phyllanthus emblica, Terminalia chebula and Terminalia belerica fruits powders in equal proportion), cashew leaf, Aloe vera and water (control) on complete dentures of institutionalized elderly. Study population consisted of 50 institutionalized elderly of Mangalore, Karnataka, with 10 in each group. Swabs were collected from the dentures before and after the use of denture cleansing tablet, Triphala, cashew leaf, Aloe vera, and water (control). Thereafter, the swabs were cultured on Sabouraud dextrose agar and the total candida counts were determined. Denture cleansing tablet and Triphala Churna showed a statistically significant reduction in Candida counts (P < 0.05). Denture cleansing tablet and Triphala Churna were found to be more effective. PMID:24812470

  3. Dry eye symptoms and signs in long-term contact lens wearers.

    PubMed

    Kastelan, Snjezana; Lukenda, Adrian; Salopek-Rabati?, Jasminka; Pavan, Josip; Gotovac, Marta

    2013-04-01

    The aim of this study is to analyze the relationship between the self-reported symptoms and objective signs of dry eye disease in long-term rigid gas-permeable (RGP) or soft contact lens (SCL) wearers. The study included 32 eyes of Caucasian RGP and SCL wearers between the age of 21 and 42 who wore contact lenses continuously on a daily basis for more than 2 years. Symptoms were assessed according to the Ocular Surface Disease Index (OSDI). Clinical assessments included corneal fluorescein staining according to the National Eye Institute (NEI) staining grid, tear film break-up time (TBUT) and Schirmer II test. There were more male (62.5%) than female (37.5%) patients with a higher proportion of RGP wearers among males (40% vs. 17%) in the study. The mean duration of daily lens wear was 10.6 +/- 5.37 hours, with a significantly higher proportion of patients who wore their lenses for prolonged hours in the soft contact lens group (p < 0.05). There was a trend towards a higher proportion of self reported mild and moderate dry eye in females and soft contact lens wearers. No RGP wearer in this study had a NEI corneal staining grid score higher than 2. A moderate negative correlation was found between daily lens wear duration and TBUT (Pearson's coefficient, r = -0.47) as well as Schirmer II values and higher OSDI score, i.e. mild and moderate dry eye categories (r = -0.50). A strong positive correlation was found between and TBUT and Schirmer II values (r = 0.74). The results of the study emphasize the importance of early and accurate diagnosis of dry eye disease for successful long term RGP and SCL contact lens wear which will hopefully motivate future larger scale investigations on dry eye related problems in contact lens wearers. PMID:23837244

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

    PubMed Central

    2012-01-01

    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 This trial aims to provide evidence on the costs and quality of dentures cast from two different commonly used impression materials; the intention is to significantly impact on the quality of denture production within NHS dentistry. Trial Registration ISRCTN Register: ISRCTN01528038 UKCRN Portfolio ID: 8305 PMID:22937901

  5. 21 CFR 872.3420 - Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...cationic polyacrylamide polymer denture adhesive. 872.3420 Section 872.3420...cationic polyacrylamide polymer denture adhesive. (a) Identification. A carboxymethylcellulose...cationic polyacrylamide polymer denture adhesive is a device composed of...

  6. 21 CFR 872.3410 - Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...carboxymethylcellulose sodium denture adhesive. 872.3410 Section 872.3410...carboxymethylcellulose sodium denture adhesive. (a) Identification. An ethylene...carboxymethylcellulose sodium denture adhesive is a device containing ethylene...

  7. 21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...polymer (modified cationic) denture adhesive. 872.3480 Section 872.3480...polymer (modified cationic) denture adhesive. (a) Identification. A polyacrylamide polymer (modified cationic) denture adhesive is a device composed of...

  8. 21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...polymer (modified cationic) denture adhesive. 872.3480 Section 872.3480...polymer (modified cationic) denture adhesive. (a) Identification. A polyacrylamide polymer (modified cationic) denture adhesive is a device composed of...

  9. 21 CFR 872.3420 - Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...cationic polyacrylamide polymer denture adhesive. 872.3420 Section 872.3420...cationic polyacrylamide polymer denture adhesive. (a) Identification. A carboxymethylcellulose...cationic polyacrylamide polymer denture adhesive is a device composed of...

  10. 21 CFR 872.3450 - Ethylene oxide homopolymer and/or karaya denture adhesive.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...oxide homopolymer and/or karaya denture adhesive. 872.3450 Section 872.3450...oxide homopolymer and/or karaya denture adhesive. (a) Identification. Ethylene oxide homopolymer and/or karaya denture adhesive is a device composed of...

  11. 21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...polymer (modified cationic) denture adhesive. 872.3480 Section 872.3480...polymer (modified cationic) denture adhesive. (a) Identification. A polyacrylamide polymer (modified cationic) denture adhesive is a device composed of...

  12. 21 CFR 872.3420 - Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...cationic polyacrylamide polymer denture adhesive. 872.3420 Section 872.3420...cationic polyacrylamide polymer denture adhesive. (a) Identification. A carboxymethylcellulose...cationic polyacrylamide polymer denture adhesive is a device composed of...

  13. 21 CFR 872.3420 - Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...cationic polyacrylamide polymer denture adhesive. 872.3420 Section 872.3420...cationic polyacrylamide polymer denture adhesive. (a) Identification. A carboxymethylcellulose...cationic polyacrylamide polymer denture adhesive is a device composed of...

  14. Effect of surface treatments on shear bond strength of denture teeth to denture base resins

    PubMed Central

    Bahrani, Farideh; Khaledi, Amir Ali Reza

    2014-01-01

    Background: Debonding of denture teeth from denture bases is the most common failure in removable dentures. The purpose of this study was to evaluate the effect of surface treatments on shear bond strength of denture teeth to heat-polymerized and autopolymerized denture base resins. Materials and Methods: In this experimental in vitro study, 60 maxillary central incisor acrylic teeth were divided into two groups. Group M was polymerized with heat-polymerized acrylic resin (Meliodent) by compression molding technique and group F was processed by autopolymerized acrylic resin (Futura Gen) by injection molding technique. Within each group, specimens were divided into three subgroups according to the teeth surface treatments (n = 10): (1) ground surface as the control group (M1 and F1), (2) ground surface combined with monomer application (M2 and F2), and (3) airborne particle abrasion by 50 ?m Al2O3 (M3 and F3). The shear bond strengths of the specimens were tested by universal testing machine with crosshead speed of 5 mm/min. Data were analyzed by two-way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) tests (P < 0.05). Results: The mean shear bond strengths of the studied groups were 96.40 ± 14.01, 124.70 ± 15.64, and 118 ± 16.38 N for M1, M2, and M3 and 87.90 ± 13.48, 117 ± 13.88, and 109.70 ± 13.78 N for F1, F2, and F3, respectively. The surface treatment of the denture teeth significantly affected their shear bond strengths to the both the denture base resins (P < 0.001). However, there were no significant differences between the groups treated by monomer or airborne particle abrasion (P = 0.29). The highest percentage of failure mode was mixed in Meliodent and adhesive in Futura Gen. Conclusion: Monomer application and airborne particle abrasion of the ridge lap area of the denture teeth improved their shear bond strengths to the denture base resins regardless of the type of polymerization. PMID:24688570

  15. Fabrication of complete denture bases reinforced with polyethylene woven fabric.

    PubMed

    Cheng, Y Y; Chow, T W

    1999-12-01

    Incorporation of 5 layers of woven, high-modulus polyethylene fiber into acrylic resin denture bases produces substantial improvements in mechanical properties and dimensional changes. A modified split-pack technique has been developed using conventional dental-laboratory compression molding to accommodate multiple layers of woven fabric in complete denture bases. A recess formed in the resin by a spacer allows the reinforcement to be embedded in the denture base without exposing the fibers. Embedded fibers do not compromise the esthetics of complete dentures. PMID:10895680

  16. Treatment planning of a partially edentulous case.

    PubMed

    Andreiotelli, Marina; Smeekens, Sjoerd

    2009-01-01

    In the present article, the advantages and disadvantages of three treatment options (clasp-retained removable partial dentures, tooth-supported telescopic retained partial dentures, and implant-supported/retained prostheses) are discussed. Furthermore the case of a 44-year-old woman with shortened and interrupted dental arches is presented. The treatment selected for the case is revealed, and the rationale governing the decision is discussed. The treatment sequence is then outlined and the final outcome is presented and discussed according to the literature. PMID:19704925

  17. An alternative approach in fabrication of fixed complete dentures using a duplicate denture.

    PubMed

    Afshari, Fatemeh S; Hallas, Matthew B; Knoernschild, Kent L

    2012-10-01

    The traditional prosthetic steps in the fabrication of a fixed complete denture after implant osseointegration include final impression, verification of implant positioning in the working cast, mounting of the working cast, and mock denture wax trial insertion prior to the laboratory fabrication of the metal substructure; however, in patient scenarios of immediate loading of implants, the interim conversion prosthesis can be used to advance from the final impression to the milling of the underlying framework in one appointment. Consistency in the initial wax trial insertion, radiographic guide, and intraoral positioning of the conversion prosthesis can result in a well-designed definitive prosthesis in less time with the use of the existing duplicate complete denture. PMID:22672368

  18. Forgotten denture in a hemiplegic patient.

    PubMed

    Kim, Hyo-Sang; Kim, Chang-Hwan; Kim, Myeong-Ok; Joa, Kyung-Lim; Chung, Hyung; Jung, Han-Young

    2014-03-01

    A 74-yr-old man developed left hemiplegia because of a right middle cerebral artery territory infarction and also had clinical features of dysphagia and speech difficulty. At that time, he complained of neck pain, but the symptom was ignored because he had a nasogastric tube and had been diagnosed with a huge epiglottic cyst that had already shown several symptoms such as severe hoarseness and throat discomfort. A videofluoroscopic swallowing study was planned to find out the cause and the type of dysphagia. On the videofluoroscopic swallowing study, a foreign body was found at the hypopharynx. Surprisingly, it was confirmed as a denture. After removing the denture, the patient's swallowing and speech difficulty were significantly improved. This case emphasizes the need for elderly stoke patients presenting with dysphagia or communication problems to receive more careful history taking and a more complete physical examination, with the cooperation of several clinical departments. PMID:24141105

  19. In search of a suitable denture marker.

    PubMed

    Thomas, C J; Mori, T; Miyakawa, O; Chung, H G

    1995-06-01

    The ID-Band (SDI AB, Sweden) has become the standard, internationally and FDI accepted denture marking system. In Australia however the strip is not easily obtainable and is expensive. Two other materials have been trialled as possible alternatives: (1) Titanium foil (9 microns) and (2) Ho Band (matrix) (3 microns) (Lorvic Corp, USA). All three bands were tested for tensile strength and elongation at temperatures: RT, 700 degrees and 900 degrees C. As the ID- and Ho Bands are both 18-8 stainless steel their performance was similar. The 18-8 was stronger, had a higher percentage break point and a higher elongation. The latter meant that it was softer and could be more easily inscribed and was therefore more suitable for denture marking. T1 is becoming increasingly used in dentistry but in spite of its abundance it is not likely to replace stainless steel for denture marking at present. On the other hand the Ho Band is cheaper, more readily available and it could replace ID-Band for use in Australia. An alternative paper based marking system is also presented together with the rationale for its use. PMID:9227068

  20. Comparison of the clinical abrasion resistance of six commercially available denture teeth

    Microsoft Academic Search

    Con Jooste; Greta Geerts; Laurie Adams

    1997-01-01

    Purpose. Clinical abrasion of denture teeth has certain implications when dentures are worn in excess of the average useful lifetime. The purpose of this study was to evaluate clinical denture tooth wear over a period of 3 years.Material and Methods. The wear of six commercially available denture teeth (Premierdent, Acrotone, Vitapan, Rx1, Duravite, and Ivoclar Orthosit) and a seventh combination

  1. Determination of Candida species nestled in denture fissures.

    PubMed

    Koba, Chiharu; Koga, Chihiro; Cho, Tamaki; Kusukawa, Jingo

    2013-07-01

    With the growing number of elderly individuals, Candida is occasionally recognised as a fungal cause of aspiration pneumonia. In addition, there are numerous investigational reports on oral candidiasis. However, there are currently no reports on Candida contamination of denture base materials. This study was conducted to investigate Candida species in the oral cavity, denture parts and oral lesions of older/elderly subjects with oral candidiasis. The Candida strains were isolated and the species identified. Candida was also cultured in a medium with sample of denture resin and observed under an electron microscope. The results demonstrated the presence of several Candida species in the lesions of the oral mucosa and the surface and inner portions of the dentures. The following species of Candida were detected: Candida albicans, Candida glabrata, Candida tropicalis and Candida parapsilosis. Using electron microscopy, the invasion of Candida was observed in the incomplete polymerized resin base material and/or through microcracks (fissures) that have a tendency to form in used dentures. It was concluded that Candida may be present on the surface as well as the deeper portions of dentures. In addition, it appeared necessary to consider denture and oral cavity cleaning and the risks of remaking old dentures. PMID:24648980

  2. [Microwave technology for fabricating the bases of plate dentures].

    PubMed

    Markov, B P; Pan, E G; Novikova, O B; Korneev, S V; Poiurovskaia, I Ia; Markova, G B

    1998-01-01

    Polymerization of basic acrylic heat-hardened plastic under the effect of UHF exposure is studied. Specimens and standard bases of dentures from Russian acrylic plastic widely used in orthodontics were used in experiment. Plastics polymerized in UHF field and in water bath were compared. Experiments helped develop a method for making removable dentures using microwaves. PMID:10067416

  3. Determination of Candida species nestled in denture fissures

    PubMed Central

    KOBA, CHIHARU; KOGA, CHIHIRO; CHO, TAMAKI; KUSUKAWA, JINGO

    2013-01-01

    With the growing number of elderly individuals, Candida is occasionally recognised as a fungal cause of aspiration pneumonia. In addition, there are numerous investigational reports on oral candidiasis. However, there are currently no reports on Candida contamination of denture base materials. This study was conducted to investigate Candida species in the oral cavity, denture parts and oral lesions of older/elderly subjects with oral candidiasis. The Candida strains were isolated and the species identified. Candida was also cultured in a medium with sample of denture resin and observed under an electron microscope. The results demonstrated the presence of several Candida species in the lesions of the oral mucosa and the surface and inner portions of the dentures. The following species of Candida were detected: Candida albicans, Candida glabrata, Candida tropicalis and Candida parapsilosis. Using electron microscopy, the invasion of Candida was observed in the incomplete polymerized resin base material and/or through microcracks (fissures) that have a tendency to form in used dentures. It was concluded that Candida may be present on the surface as well as the deeper portions of dentures. In addition, it appeared necessary to consider denture and oral cavity cleaning and the risks of remaking old dentures. PMID:24648980

  4. [Contemporary methods and mobile denture cleansers and theirs significance for older population].

    PubMed

    Strajni?, Ljiljana; Doki?, Miodrag; Vucini?, Predrag

    2011-01-01

    A dramatic increase in the number of people living in their seventies, eighties and nineties is associated with a loss of teeth and the use of mobile dentures. The aim of this paper was to highlight the consequences of poor denture hygiene on oral and general health in vulnerable elderly people, in long-term hospitalized elderly patients and in long-term institutionalized elderly in nursing homes. DENTURE DEPOSITS AND CONSEQUENCES OF POOR DENTURE HYGIENE: The number of bacteria living in the mouth is getting larger after putting denture on. Namely, a small "space" develops between jaw and denture, creating perfect conditions for bacterial growth. Denture becomes a "reservoir" of micro-organisms. Denture deposits such as bacterial plaque, fungi, tartar and remnants could be responsible for stomatitis prothetica, cheilitis angularis, inflammatory fibrous hyperplasia, halitosis (bad breath), dental caries in mobile denture carriers, mucositis and periimplantitis in mobile implant over-dentures carriers, accelerated destruction of denture materials for underlying, such as denture base soft liners, respiratory airways diseases, bacterial endocarditis and gastrointestinal infections. REMOVAL OF DENTURE DEPOSITS: It is recommendable to combine mechanical and chemical denture cleaning. Denture submersion into a commercial cleansing solution for less than one hour is an effective cleaning method. Commercial cleanser: specifically intended for dentures with metal parts should be used for those dentures. Commercial cleansers with a new component of silicon polymer, whose thin layer surrounds all denture surfaces and disables oral bacteria to agglomerate, are effective and useful. Preventive hygienic treatments are very important in hospitals and homes for the aged, bearing in mind that old and ill persons reside here. Those institutions are recommended to get equipped with ultrasound denture cleaners. IMPORTANCE OF WRITTEN BROCHURE ON PROPER DENTURE HYGIENE: Patients should be verbally instructed and showed about cleaning techniques, but also written instructions inform of brochure should be distributed in order to achieve better effects. PMID:22097118

  5. A provisional fixed partial denture for an implant prosthesis.

    PubMed

    Hansen, Paul A; Kim, Eunghwan

    2010-01-01

    This article presents a technique for fabricating an esthetic provisional restoration on multiple implants. Fabricating a provisional restoration allows the dentist to make a replica of the desired restoration. The incisal edge can be placed for esthetics and function in the new provisional restoration, allowing patients to evaluate comfort and test their ability to speak with the contour of the provisional restoration. Patients can evaluate both the ease of cleaning the restoration and how tissue esthetics can be duplicated to their satisfaction. By adding acrylic resin to or removing it from the provisional, the dentist can easily change the restoration until the patient is satisfied with the esthetic and functional result. This technique will allow the dentist to fabricate the provisional prosthesis quickly, while the patient is in the chair. PMID:20129879

  6. Reservoir Complete Denture in a Patient with Xerostomia Secondary to Radiotherapy for Oral Carcinoma: A Case Report and Review of Literature

    PubMed Central

    Ladda, R; Kasat, VO; Gangadhar, SA; Baheti, S; Bhandari, AJ

    2014-01-01

    Xerostomia refers to a subjective sensation of dry mouth. A variety of factors can cause xerostomia including radiotherapy (RT) given for the treatment of oral carcinoma. Depending on the cause, treatment is provided to a patient suffering from xerostomia. In severe xerostomia salivary substitutes can be used and if the xerostomic patient is edentulous, then reservoir space for artificial salivary substitute can be created in partial as well as complete upper or lower dentures. The methods advocated so far for incorporating reservoir space in mandibular complete denture are costly, time consuming and require extra-laboratory steps. Therefore, the purpose of this article is to report a simpler method for fabrication of mandibular reservoir denture in a 67-year-old edentulous male patient suffering from xerostomia due to RT for oral carcinoma. PMID:24761252

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

    PubMed Central

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

    2013-01-01

    PURPOSE The aim of this study was to investigate the destructive effects of biofilm formation and/or biocorrosive activity of 6 different oral microorganisms. MATERIALS AND METHODS 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 (?=0.05). RESULTS 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); microorganisms diffused at least 52% of the denture base surface. The highest median quantitative biofilm value within all the denture base materials was obtained with P. aeruginosa on Lucitone 550. The type of denture base material did not alter the diffusion potential of the microorganisms significantly (P>.05). CONCLUSION All the tested microorganisms had destructive effect over the structure and composition of the denture base materials. PMID:23755339

  8. The effect of denture design and fixatives on the retention of mandibular complete dentures tested on a novel in-vitro edentulous model.

    PubMed

    Johnson, A; Al-Kaisy, N; Miller, C A; Martin, N

    2013-06-01

    The aim of this study was to evaluate the effect of the design (extension and adaptation) of a mandibular complete acrylic denture and the use of denture adhesives using a novel in-vitro edentulous model. The model is a highly anatomically accurate replica based on a moderately resorbed human mandibular edentulous arch. The model has been designed and fabricated by means of an elaborate clinical and technical process that employs synthetic elastomeric materials with properties that attempts to reproduce in-vitro characteristics of the soft tissues overlying the ridges and immediate reflected tissues. This model was used to measure and compare the retention of mandibular dentures ofvarying designs (well-fitting, over- and under-extended) with and without the aid of denture fixatives. Retention tests were conducted with different volumes of artificial saliva at a cross head speed of 50 mm/min with 4 equidistant holding points on the denture occlusal surface, using a universal tensile testing machine in an axial pull direction. The effect of three denture adhesives on denture retention was also tested on the same denture types at different times over a period of 5 hours and beyond. The in-vitro model presented can be effectively used to test the retention of mandibular complete dentures. The speed of dislodgement force and amount of saliva are important variables in mandibular denture retention. The retention of well-fitting dentures was statistically higher than that of ill-fitting dentures. A significantly higher retention force was needed to dislodge mandibular dentures (well and ill-fitting dentures) when using a denture adhesive. PMID:23888529

  9. Effect of multifocal lens glasses on the stepping patterns of novice wearers.

    PubMed

    Beschorner, Kurt E; Milanowski, Autumn; Tomashek, Dennis; Smith, Roger O

    2013-09-01

    Multifocal lens glasses (MfLs) negatively affect vision, increase falling risk and contribute to gait changes during stepping. Previous studies on the effects of MfLs on gait have focused on experienced wearers. Thus, the initial response of first-time wearers, who may face significant challenges in adapting to these glasses, is not well understood. This study aimed to quantify the effects of MfLs on novice wearers during stepping up and down. Additionally, young adults were compared against a middle-aged adults to determine the validity of convenience sampling in testing novice response to MfLs. Fifteen young adults (18-34 y.o.) and seven middle-aged adults (46-56 y.o.) were recruited to perform stepping trials while wearing progressive MfLs and blank single lens glasses. Participants stepped up and down from a 75 mm and 150 mm step in randomized order. Step placement, minimum toe clearance, lower body kinematics and stepping time were measured during step up. Step placement, minimum heel clearance, vertical forces and stepping time were measured during step down. MfLs significantly increased toe clearance in the lead and trailing legs, hip flexion, knee flexion and stepping time during step up and increased vertical forces and stepping time during step down. Step placement and hip angle explained 17% of the toe clearance variability. Changes during step up suggest a more conservative adaptation while increased forces during step down suggest a reduced level of control. No age group effects were observed, which supports the use of convenience sampling for evaluating the novice response to MfLs. PMID:23770232

  10. Reactive dentures: a novel approach to decrease residual ridge resorption

    PubMed Central

    Reddy, Kesava K; Prasanna, Renuka G S; Sundaresh, K J; Mallikarjuna, Rachappa

    2013-01-01

    The need for reduction of traumatic forces transmitted through the prosthesis has long been recognised and studies have shown that either a soft acrylic resin/silicone rubber can serve as a stress distributor and absorb some of the forces applied to the teeth. These dentures permit reaction to impacting forces which allows independent movement of one or more teeth in function unlike the conventional dentures. A completely edentulous patient with adequate inter-ridge distance was selected for the case, the dentures with soft liner placed between the patient's teeth and denture base were fabricated. This report presents a completely new technique to reduce the ridge resorption and facilitate patient comfort. PMID:23576651

  11. Fabricating an immediate denture for a medically compromised elderly patient.

    PubMed

    Lee, Ju-Hyoung

    2015-04-01

    Fabricating an immediate denture (ID) in the conventional manner may be complicated and difficult. An alternative technique is described for the fabrication of an ID that eliminates the need for an interim prosthesis and reduces treatment time. PMID:25681356

  12. The various methods and benefits of denture labeling

    PubMed Central

    Datta, Pankaj; Sood, Sonia

    2010-01-01

    Labeled dentures can be important in identifying the owners in case of an accident, loss of memory, states of unconsciousness, being inadvertently misplaced on admission to a hospital or, in identifying the bodies of those who have died in a calamity. Positive identification through labeled dentures plays a key role in forensic scenario. Marking dentures has been considered as an important part of forensic dentistry, although no standardized method is followed. A number of labeling systems are available and can be broadly separated into either surface marking methods or inclusion systems. Each of the commonly described techniques is assessed with respect to their strengths and weaknesses. The more contemporary methods, though hi-tech, are expensive and may not be suitable for all dental practitioners to use. This article reviews the strengths and weaknesses of various methods involved in labeling dentures concluding by recommending that this valuable topic be included in the dental curriculum in India. PMID:21731340

  13. 21 CFR 872.3300 - Hydrophilic resin coating for dentures.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3300 Hydrophilic resin coating for dentures. (a) Identification. A hydrophilic resin...

  14. 21 CFR 872.3300 - Hydrophilic resin coating for dentures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3300 Hydrophilic resin coating for dentures. (a) Identification. A hydrophilic resin...

  15. 21 CFR 872.3570 - OTC denture repair kit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...b) Classification. Class II. The special controls for this device are FDA's: (1) “Use of International Standard ISO 10993 ‘Biological Evaluation of Medical Devices—Part I: Evaluation and Testing,’ ” and (2) “OTC Denture...

  16. 21 CFR 872.3570 - OTC denture repair kit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...b) Classification. Class II. The special controls for this device are FDA's: (1) “Use of International Standard ISO 10993 ‘Biological Evaluation of Medical Devices—Part I: Evaluation and Testing,’ ” and (2) “OTC Denture...

  17. 21 CFR 872.3560 - OTC denture reliner.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...b) Classification. Class II. The special controls for this device are FDA's: (1) “Use of International Standard ISO 10993 ‘Biological Evaluation of Medical Devices—Part I: Evaluation and Testing,’ ” and (2) “OTC Denture...

  18. Denture identification using unique identification authority of India barcode

    PubMed Central

    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. PMID:23960418

  19. Patient-fabricated denture prostheses: a clinical report.

    PubMed

    Mamoun, John S; Cervini, Edward; Gagoh, Oscar K; Malmström, Hans S

    2004-11-01

    This article describes 2 patients who presented with self-made dentures. Each patient had a different motivation for avoiding professional dental treatment. One patient made her own denture because she could not afford dental care, while the other could afford such care but avoided treatment due to a dental phobia. A discussion of diagnosis and treatment planning is presented for each situation. PMID:15523330

  20. 21 CFR 872.3760 - Denture relining, repairing, or rebasing resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3760 Denture relining, repairing, or rebasing resin. (a) Identification. A denture...

  1. 21 CFR 872.3760 - Denture relining, repairing, or rebasing resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3760 Denture relining, repairing, or rebasing resin. (a) Identification. A denture...

  2. 21 CFR 872.3760 - Denture relining, repairing, or rebasing resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3760 Denture relining, repairing, or rebasing resin. (a) Identification. A denture...

  3. Remedy for Repeated Implant Retained Denture Fracture-A Challenging Case Report

    PubMed Central

    Reddy M, Ramu; Metta, Kiran Kumar; Charry N, Sudheer; B, Chittaranjan

    2014-01-01

    The most common site of fracture in a maxillary or a mandibular complete denture is along an anteroposterior line that coincides with the labial notch in in the denture which used to provide the frenum relief. Osseointegrated implants have been a boon to the patients who are completelly edentulous and are not satisfied with the conventional removable complete denture approach.Implant supported dentures have proven to provide superior retention and support for removable complete dentures. Nevertheless, fracture of the denture bases is a common complication of implant-supported mandibular overlay dentures,ecspecially when the artificial denture is opposing natural dentition. This article describes and illustrates a method of reinforcing implant-supported mandibular overdentures to overcome this problem. PMID:25584333

  4. Corneal topographic changes after refitting polymethylmethacrylate contact lens wearers into rigid gas permeable materials.

    PubMed

    Novo, A G; Pavlopoulos, G; Feldman, S T

    1995-01-01

    Polymethylmethacrylate (PMMA) contact lenses can alter corneal shape and induce corneal warpage or distortion. The purpose of our study was to determine the effects on the corneal topography after immediate refitting of long-term PMMA contact lens wearers into rigid gas permeable (RGP) materials. Six eyes with contact lens induced corneal warpage from PMMA contact lenses were assessed using the Topographical Mapping System-1. Statistical analysis was performed for the following variables prior to and approximately 6 months after contact lens refitting: best spectacle visual acuity, manifest refraction, surface regularity index, surface asymmetry index, keratometry, and simulated keratometry. Best spectacle visual acuity improved an average of 1.8 +/- 1.0 (mean +/- SD, P < 0.05) lines of Snellen visual acuity, while refraction did not change appreciably. The surface regularity index diminished by 0.51 +/- 0.32 (P = 0.01). The surface asymmetry index improved by 0.32 +/- 0.26 (P < 0.05). There was a good correlation between keratometry and simulated keratometry, and neither changed significantly after refitting with RGP contact lenses. All general topographic patterns remained unchanged throughout the study. Immediate refitting of long-term PMMA contact lens wearers into RGP materials of similar fit allows a slightly more regular and symmetric central corneal shape, which can result in improved spectacle visual acuity. The general corneal topographic patterns of contact lens induced corneal warpage did not change or improve after refitting to RGP material. PMID:7712607

  5. Photodynamic inactivation of microorganisms present on complete dentures. A clinical investigation

    Microsoft Academic Search

    Daniela Garcia Ribeiro; Ana Cláudia Pavarina; Lívia Nordi Dovigo; Ewerton Garcia de Oliveira Mima; Ana Lucia Machado; Vanderlei Salvador Bagnato; Carlos Eduardo Vergani

    The aim of this study was to evaluate the effectiveness of photodynamic therapy (PDT) for the disinfection of complete dentures.\\u000a Biofilm samples were collected from dentures of 60 denture users who were randomly divided into four experimental groups (n?=?15 each): subjects whose maxillary dentures were sprayed with 50 and 100 mg\\/l of Photogem® suspension (groups P50S and\\u000a P100S) and patients whose

  6. Spectrogram Analysis of Complete Dentures with Different Thickness and Palatal Rugae Materials on Speech Production

    PubMed Central

    Zaki Mahross, Hamada; Baroudi, Kusai

    2015-01-01

    Objective. To investigate the influence of reproduction of different thickness and palatal rugae materials on complete dentures speech using Computerized Speech Lab (CSL) (spectrogram). Materials and Methods. Three completely edentulous male patients (aged 50–60 years) were selected for reading a paragraph. Twelve upper dentures were constructed, four for each patient. The patients' speech groups were divided into five groups, Group I: patients without dentures; Group II: patients rehabilitated with conventional acrylic dentures; Group III: patients with conventional acrylic dentures with rugae reproduction; Group IV: patients with dentures with metallic framework of minimal thickness and direct ragged metallic palatal surface at rugae area; Group V: patients with dentures with palatal rugae constructed from resilient acrylic resin material with thickness less than conventional denture. Speech samples were recorded after insertion of each denture for groups using Computerized Speech Lab (CSL) (spectrogram). The sounds selected were lingopalatal /s/z/sh/t/d/ and /l/. Results. Group III produced high mean significant difference with /sh/t/ sound. For Group IV, the difference was noticed with /s/z/sh/t/ and /d/ sounds, while for Group V the difference was shown with /z/l/ sound (P < 0.05). Conclusion. It is recommended to reproduce the rugae area in complete denture because the phonetic quality of complete denture with rugae is superior to the conventional denture.

  7. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Karaya and sodium borate with or without acacia denture adhesive. 872.3400 Section...Karaya and sodium borate with or without acacia denture adhesive. (a) Identification...karaya and sodium borate with or without acacia denture adhesive is a device...

  8. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Karaya and sodium borate with or without acacia denture adhesive. 872.3400 Section...Karaya and sodium borate with or without acacia denture adhesive. (a) Identification...karaya and sodium borate with or without acacia denture adhesive is a device...

  9. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Karaya and sodium borate with or without acacia denture adhesive. 872.3400 Section...Karaya and sodium borate with or without acacia denture adhesive. (a) Identification...karaya and sodium borate with or without acacia denture adhesive is a device...

  10. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Karaya and sodium borate with or without acacia denture adhesive. 872.3400 Section...Karaya and sodium borate with or without acacia denture adhesive. (a) Identification...karaya and sodium borate with or without acacia denture adhesive is a device...

  11. Fabrication of conventional complete dentures for a left segmental mandibulectomy patient: A clinical report

    Microsoft Academic Search

    Shu-Hui Mou; Tsongi Chai; Yuh-Yuan Shiau; Juo-Song Wang

    2001-01-01

    Without preprosthetic reconstructive surgery, denture fabrication for mandibulectomy patients becomes extremely difficult. Implant-assisted overdentures may improve denture retention and stability, but some patients cannot afford this treatment. For the segmental mandibulectomy patient described in this report, properly fabricated conventional complete dentures provided comfort and sufficient function. (J Prosthet Dent 2001;86:582-5.)

  12. The effect of mechanical roughening and chemical treatment on shear bond strength of urethane dimethacrylate denture base resin

    Microsoft Academic Search

    Fazrina T. M. Ariff; Norsiah Yunus; Mirza R. Baig

    2011-01-01

    Relining of ill-fitting denture is often required to establish the fit of denture base, hence better retention and stability of the prostheses. However clinical success depends on the ability of reline resin to bond with denture base. The effect of surface preparations of urethane dimethacrylate (UDMA) denture base resin (Eclipse) on the shear bond strength (SBS) to auto-polymerizing polyethyl methacrylate

  13. A randomized prospective clinical trial on the effectiveness of three treatment modalities for patients with lower denture problems

    Microsoft Academic Search

    G. M. Raghoebar; H. J. A. Meijer; B. Stegenga; A. Vissink

    2003-01-01

    Treatment of lower denture complaints of patients with an edentulous mandible with a height of at least 15 mm can consist of meticulous construction of a new set of dentures (CD), construction of a new set of dentures following preprosthetic surgery to enlarge the denture-bearing area (PPS), or construction of an implant-retained mandibular overdenture (IRO). The aim of this prospective

  14. Anticandidal Activity and Biocompatibility of a Rechargeable Antifungal Denture Material

    PubMed Central

    Villar, Cristina C.; Lin, Alan L.; Cao, Zhengbing; Zhao, Xiang-Ru; Wu, Li-An; Chen, Shuo; Sun, Yuyu; Yeh, Chih-Ko

    2013-01-01

    Objectives Candida-associated denture stomatitis is a recurrent and debilitating oral mucosal disease. Development of anticandidal denture materials represents a promising strategy to manage this condition. We have previously shown that miconazole incorporated in methacrylic acid (MAA) copolymerized diurethane dimethacrylate (UDMA) denture materials has long-term anticandidal activity. In this study, we examined the ability of culture medium conditioned with drug-free- or miconazole-MAA-UDMA discs to prevent Candida infection in an in vitro oral epithelial cell/Candida albicans co-culture system. Material and Methods Candida albicans (C. albicans) induced OKF6/TERT-2 cell damage was quantified by the release of lactate dehydrogenase from epithelial cells, cytokine production was quantified using protein cytokine arrays, and the expression of C. albicans genes was measured by RT-qPCR. Results C. albicans had limited growth with altered expression levels of secreted aspartyl proteinase-2 and -5 in culture medium conditioned by miconazole-MAA-UDMA discs. Significantly, the ability of C. albicans to induce oral epithelial cell damage and trigger epithelial proinflammatory cytokine production was also inhibited by miconazole disc conditioned media. Conclusion Miconazole released from MAA-UDMA denture materials effectively prevents the development of candidal infection in an in vitro oral epithelial system. Further characterization of this drug-rechargeable denture material is warranted. PMID:22957799

  15. Changes in jaw relations and activity of masticatory muscles in patients with immediate complete upper dentures.

    PubMed

    Tallgren, A; Tryde, G; Mizutani, H

    1986-07-01

    A longitudinal radiographic cephalometric and electromyographic investigation was performed on eighteen subjects provided with an immediate complete upper and a partial lower denture. The observation stages were: before final extractions and 7 weeks, 6 months and 1 year after denture insertion. The cephalometric analysis was based on measurements from lateral head films taken in centric occlusion. The EMG activity of the anterior temporal and masseter muscles was studied in postural position, light tapping and in maximal clench. The changes in jaw and occlusal relationships due to resorption of the edentulous maxillary ridge were slight, the mean decrease in occlusal vertical dimension during one year being 0.7 mm. The EMG clench activity at the pre-extraction stage, when the patients occluded on a residual anterior dentition, showed low mean values round 100 microV, and a further decrease was observed at the post-insertion stage. At the 1-year stage all muscles displayed significant increases to above the post-insertion level. The jaw muscle activity in light tapping and in postural position generally showed no significant mean changes during the observation period. The results indicate that preservation of a residual dentition in the lower jaw prevents marked changes in jaw and occlusal relationships and resulting changes in muscle activity. PMID:3463720

  16. Treatment for acute craniomandibular dysfunction symptoms in edentulous patients with unserviceable or no existing complete dentures.

    PubMed

    Runyan, D A; Shimoda, L M; McGowan, M J

    1989-11-01

    This article describes techniques to make unserviceable complete dentures rapidly serviceable and to facilitate using them in the diagnosis and treatment of acute craniomandibular dysfunction symptoms in edentulous patients. A technique is described to make complete dentures rapidly in the event that the complete dentures cannot be made serviceable or the patient has no complete dentures. This technique uses the TRIAD visible light-cure system. Once the complete dentures are made, they can be used alone or in conjunction with an occlusal splint for the diagnosis and treatment of acute craniomandibular dysfunction symptoms. PMID:2691657

  17. Deterioration of polymethyl methacrylate dentures in the oral cavity.

    PubMed

    Matsuo, Hiroshi; Suenaga, Hanako; Takahashi, Masatoshi; Suzuki, Osamu; Sasaki, Keiichi; Takahashi, Nobuhiro

    2015-04-01

    Polymethyl methacrylate (PMMA)-made prostheses used in the oral cavity were evaluated by multimodal assessment in order to elucidate the biodeterioration of PMMA. In used dentures (UD), the micro-Vickers hardness of the polished denture surface and denture basal surface was lower than that of the torn surface (p<0.05), whereas the shaved surface approximately 100 µm from the polished surface showed a similar value to the torn surface. By contrast, there were no differences among these surfaces in new resin (NR). The volatile content of UD was higher than that of NR (p<0.05). Component analysis by ATR-FTIR showed specific spectra (1,700-1,400 cm(-1)) only in UD. This study revealed that PMMA deteriorated during long-term use in the oral cavity in terms of hardness and volatile content with component alteration, and suggests the involvement of biodeterioration, possibly due to saliva and oral microbiota. PMID:25740307

  18. Use of a digitally planned and fabricated mandibular complete denture for easy conversion to an immediately loaded provisional fixed complete denture. Part 1. Planning and surgical phase.

    PubMed

    Lozada, Jaime L; Garbacea, Antoanela; Goodacre, Charles J; Kattadiyil, Mathew T

    2014-01-01

    This article describes a unique prosthetically driven protocol that uses computeraided engineering to develop sophisticated, scientific algorithms that guide the fabrication of a conversion denture using the AvaDent Digital Denture system (Global Dental Science). This system is combined with Nobel Clinician (Nobel Biocare) implant-planning software to optimize accuracy and to make it easier and faster to convert a denture to an immediately loaded provisional implant supported fixed complete denture following implant placement, using a NobelGuide surgical template. PMID:25191881

  19. Trial of experimental toothpastes regarding quality for cleaning dentures.

    PubMed

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

    2012-01-01

    The aim of this study was to evaluate the efficacy of experimental toothpastes for removing denture biofilm by means of a randomized crossover trial. Thirty volunteers brushed their dentures using a brush and four pastes: (1) Corega refreshing mint (control), (2) 0.2% chloramine T, (3) 1.0% chloramine T, and (4) 0.01% fluorosurfactant. Each paste was used for 7 days, and participants were randomized to use them according to one of four sequences. Biofilm was disclosed (neutral red) after each period, photographed, and quantified by means of a software program. All experimental toothpastes were similar to the control in terms of posttreatment biofilm coverage. PMID:22371837

  20. Comparative Evaluation of Sorption, Solubility and Microhardness of Heat Cure Polymethylmethacrylate Denture Base Resin & Flexible Denture Base Resin

    PubMed Central

    Bulbule, Nilesh; Kulkarni, Shilpa; Shah, Riddhi; Kakade, Dilip

    2014-01-01

    Aim: The aim of the study was to evaluate and compare sorption, solubility and microhardness of heat cure polymethylmethacrylate (PMMA) denture base resin and flexible (thermoplastic polyamide nylon) denture base resin. Materials and Methods: Sorption, solubility and microhardness were assessed to determine compliance with ADA Specification no. 12. Results were assessed using statistical and observational analyses. Result: All materials satisfied ADA requirements for sorption, solubility and microhardness. Heat cure PMMA showed more sorption, solubility and microhardness than flexible (thermoplastic polyamide nylon). Conclusion: Flexible (thermoplastic polyamide nylon) resin absorbs less water, is less soluble and is more flexible than PMMA. PMID:25302291

  1. Denture-Related Stomatitis Is Associated with Endothelial Dysfunction

    PubMed Central

    Osmenda, Grzegorz; Nowakowski, Daniel; Wilk, Grzegorz; Maci?g, Anna; Miko?ajczyk, Tomasz; Sagan, Agnieszka; Filip, Magdalena; Dró?d?, Miros?aw; Guzik, Tomasz J.

    2014-01-01

    Oral inflammation, such as periodontitis, can lead to endothelial dysfunction, accelerated atherosclerosis, and vascular dysfunction. The relationship between vascular dysfunction and other common forms of oral infections such as denture-related stomatitis (DRS) is unknown. Similar risk factors predispose to both conditions including smoking, diabetes, age, and obesity. Accordingly, we aimed to investigate endothelial function and major vascular disease risk factors in 44 consecutive patients with dentures with clinical and microbiological features of DRS (n = 20) and without DRS (n = 24). While there was a tendency for higher occurrence of diabetes and smoking, groups did not differ significantly in respect to major vascular disease risk factors. Groups did not differ in main ambulatory blood pressure, total cholesterol, or even CRP. Importantly, flow mediated dilatation (FMD) was significantly lower in DRS than in non-DRS subjects, while nitroglycerin induced vasorelaxation (NMD) or intima-media thickness (IMT) was similar. Interestingly, while triglyceride levels were normal in both groups, they were higher in DRS subjects, although they did not correlate with either FMD or NMD. Conclusions. Denture related stomatitis is associated with endothelial dysfunction in elderly patients with dentures. This is in part related to the fact that diabetes and smoking increase risk of both DRS and cardiovascular disease. PMID:25045683

  2. The cast aluminum denture base. Part II: Technique.

    PubMed

    Halperin, A R; Halperin, G C

    1980-07-01

    A technique to wax-up and cast an aluminum base and a method to incorporate the base into the final denture base has been discussed. This technique does not use induction casting, rather it uses two casting ovens and a centrifugal casting machine. PMID:6991680

  3. Effect of denture cleansers on metal ion release and surface roughness of denture base materials.

    PubMed

    Davi, Letícia Resende; Felipucci, Daniela Nair Borges; de Souza, Raphael Freitas; Bezzon, Osvaldo Luiz; Lovato-Silva, Cláudia Helena; Pagnano, Valéria Oliveira; Paranhos, Helena de Freitas Oliveira

    2012-01-01

    Chemical disinfectants are usually associated with mechanical methods to remove stains and reduce biofilm formation. This study evaluated the effect of disinfectants on release of metal ions and surface roughness of commercially pure titanium, metal alloys, and heat-polymerized acrylic resin, simulating 180 immersion trials. Disk-shaped specimens were fabricated with commercially pure titanium (Tritan), nickel-chromium-molybdenum-titanium (Vi-Star), nickel-chromium (Fit Cast-SB Plus), and nickel-chromium-beryllium (Fit Cast-V) alloys. Each cast disk was invested in the flasks, incorporating the metal disk to the heat-polymerized acrylic resin. The specimens (n=5) were immersed in these solutions: sodium hypochlorite 0.05%, Periogard, Cepacol, Corega Tabs, Medical Interporous, and Polident. Deionized water was used as a control. The quantitative analysis of metal ion release was performed using inductively coupled plasma mass spectrometry (ELAN DRC II). A surface analyzer (Surftest SJ-201P) was used to measure the surface roughness (µm). Data were recorded before and after the immersions and evaluated by two-way ANOVA and Tukey's test (?=0.05). The nickel release proved most significant with the Vi-Star and Fit Cast-V alloys after immersion in Medical Interporous. There was a significant difference in surface roughness of the resin (p=0.011) after immersion. Cepacol caused significantly higher resin roughness. The immersion products had no influence on metal roughness (p=0.388). It could be concluded that the tested alloys can be considered safe for removable denture fabrication, but disinfectant solutions as Cepacol and Medical Interporous tablet for daily denture immersion should be used with caution because it caused greater resin surface roughness and greater ion release, respectively. PMID:23207854

  4. How Could Contact Lens Wearers Be at Risk of Acanthamoeba Infection? A Review

    PubMed Central

    Ibrahim, Youhanna W.; Boase, David L.; Cree, Ian A.

    2010-01-01

    Contact lens wear is highly influential on the incidence of ulcerative keratitis worldwide, particularly in developed countries. The association between Acanthamoeba keratitis and contact lens wear is firmly established; it may account for up to 95% of the reported cases. Before the popularisation of soft contact lens wear, Acanthamoeba keratitis was extremely rare. In 2000 it was estimated that the number of contact lens wearers worldwide was about 80 million, out of whom 33 million were in the United States and 90% of them wore hydrogel soft lenses. Contact lens-related problems depend on many factors, such as lens material, wearing modality, lens hygiene, type of lens-caring solution, the degree of compliance of the lens user with lens wear and care procedures, lens overwear, sleeping in lenses, rate of changing lenses, and lens case hygiene. This paper is a thorough review of the literature aiming to highlight the role of one of the main risk factors of infectious keratitis, contact lens wear, and also to show the responsibility of lens users in aggravating this risk.

  5. Effect of denture cleansers on surface hardness of resilient denture liners at various time intervals- an in vitro study

    PubMed Central

    Pahuja, Rasleen Kaur; Bansal, Sanjay

    2013-01-01

    PURPOSE This study was aimed to determine the effect of two chemically distinct denture cleansers and water on the surface hardness of acrylic and silicone based soft denture liners at various time intervals. MATERIALS AND METHODS Two commonly used commercial resilient liner material were selected based on their chemical composition (silicone- and acrylic-based soft liners) for this investigation. 120 cylindrical specimens were made of 15 mm × 10 mm dimensions (according to ASTM: D-2240-64T) in a custom made metal mold. All specimens were stored in artificial saliva throughout the study. Forty specimens were cleansed daily in 0.5% sodium hypochlorite solution; forty were cleansed in sodium perborate and remaining forty specimens were daily rinsed in water. Testing was done at 1 week, 1 month, 3 months and 6 months for surface hardness using a Shore A Durometer. A mean of 3 reading for each sample was subjected to one-way ANOVA, Post Hoc test and pair-t test for statistical analysis. P values of less than 0.05 were taken as statistically significant. RESULTS Surface hardness of all the samples was significantly higher after a period of 6 months irrespective of the cleansing treatment. Minor changes were observed between control, sodium hypochlorite and sodium perborate groups with time. Greater change was observed in surface hardness of acrylic-based soft denture liners as compared to silicone-based soft liners for all groups, as time progressed. CONCLUSION Silicone-based soft denture liners performed significantly better in all cleansing treatments than acrylic-based soft denture liners. PMID:24049568

  6. Isolation and identification of viable bacteria within acrylic resin denture bases

    Microsoft Academic Search

    Yasuhisa Takeuchi; Kazuko Nakajo; Takuichi Sato; Yoko Sakuma; Keiichi Sasaki; Nobuhiro Takahashi

    \\u000a This study aimed to isolate and identify the microbial species within acrylic resin denture bases. Bacteria were detected\\u000a from within acrylic resin denture bases. Lactobacillus species, Actinomyces, Streptococcus, and Propionibacterium species were predominantly identified. The present study revealed that viable bacteria existed within acrylic resin denture\\u000a bases suggesting that the bacteria and their metabolites may be related to the deterioration

  7. Functionally Generated Amalgam Stops for Single Complete Denture: A Case Report

    PubMed Central

    Patil, Pravinkumar G.; Parkhedkar, Rambhau D.

    2009-01-01

    Single complete denture opposing natural dentition is a common occurrence in clinical practice. This article reports a case of a single complete denture with a technique of occlusal refinement by functionally generated amalgam stops condensed in prepared resin teeth after initial balancing of the denture with semi-adjustable articulator. This technique provides intimacy of contact in all excursions by carving the amalgam in plastic stage. Amalgam stops improve the efficiency of the resin teeth. Dentures fabricated using this technique require fewer and simpler post-insertion adjustments. PMID:21528030

  8. Scanning electron microscopic examination of ultrasonic and effervescent methods of surface contaminant removal from complete dentures.

    PubMed

    Raab, F J; Taylor, C A; Bucher, J A; Mann, B L

    1991-02-01

    Dentures were examined by scanning electron microscopy to evaluate removal of surface contaminants such as plaque, calculus, microflora, and cigarette smoke. Ten complete dentures were obtained during patient appointments and prepared for SEM examination. Samples from 10 control surfaces, 10 surfaces cleaned with effervescent cleansers, and 10 surfaces ultrasonically cleaned were photographed at x5000. One photograph of each sample was evaluated in random order by five judges for a total of 150 observations. Photographs were compared with one of a clean denture sample. Statistical analysis of the results validated the superiority of the ultrasonic method for cleaning dentures. PMID:2051361

  9. Halitosis manifestation and prevention means for patients with fixed teeth dentures.

    PubMed

    Zigurs, Guntis; Vidzis, Aldis; Brinkmane, Anda

    2005-01-01

    The objective of this research is to analyse the causal relationship between construction of fixed bridge dentures and the intensity of halitosis manifestations, as well as to establish basic hygiene requirements for construction of fixed dentures which would completely exclude retention of food particles and avoid bad breath. 48 patients (36 men and 12 women), who use fixed dentures for 2-10 years, have been involved in this research. 26 patients wore fixed bridge dentures made of punched tooth crowns, the other 22 patients wore cast fixed dentures. The obtained measurements of halitosis magnitude point to the close connection between bad breath and the construction of fixed dentures. Fixed dentures with tooth crown laps, saddle intermediate parts, as well as denture constructions, which impede complex of mouth hygiene measures, cause bad breath. In this research, the condition of patients' teeth, periodontium, and oral cavity hygiene have been evaluated as satisfactory; the tongue is not perceptibly coated, and patients etiologically have not experienced problems caused by respiratorial or gastrointestinal diseases. The examined patients have not complained of xerostomia problems. In conclusion, it should be admitted that fixed dentures, which make difficult or even completely impede the complex of oral cavity hygiene measures, intensify the development of halitosis. PMID:16254469

  10. 21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3480 Polyacrylamide polymer (modified cationic) denture adhesive. (a) Identification....

  11. 21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3480 Polyacrylamide polymer (modified cationic) denture adhesive. (a) Identification....

  12. Topical voriconazole therapy of Purpureocillium lilacinum keratitis that occurred in disposable soft contact lens wearers.

    PubMed

    Todokoro, Daisuke; Yamada, Norihiro; Fukuchi, Mariko; Kishi, Shoji

    2014-10-01

    The objective of this study was to describe 2 cases of keratitis caused by Purpureocillium lilacinum (formerly Paecilomyces lilacinus) that occurred in disposable contact lens users, which were successfully treated with topical voriconazole. Case 1 was a healthy 44-year-old woman, who wore weekly disposable contact lenses and had developed a superficial corneal infection in her right eye. For diagnosis, corneal scraping and molecular identification of the cultured pathogen were performed. A corneal smear revealed the presence of fungi. The pathogen was identified as P. lilacinum by traditional morphological identification of fungal culture, and this identification was confirmed by DNA sequencing of the ribosomal internal transcribed spacer (ITS) sequence. Therapy with topical fluconazole, topical pimaricin (natamycin), and oral itraconazole were ineffective. Topical voriconazole showed a significant effect, and the keratitis was successfully treated. Case 2 was a 43-year-old woman with bilateral recurrent peripheral corneal ulcers by meibomian gland dysfunction, who used therapeutic bandage contact lenses on her left eye. However, a corneal abscess with hypopyon occurred in the eye after 3 months. The microbial smear examination showed the presence of fungi and the fungal culture, and the DNA sequence of ITS region revealed that the causative agent was P. lilacinum. The susceptibility testing against antifungal agents showed that voriconazole was effective. The lesion improved gradually by topical voriconazole. As a conclusion, P. lilacinum keratitis can occur in disposable soft contact lens wearer. Early and accurate detection of the pathogenic organism is essential. Topical voriconazole was effective against P. lilacinum keratitis. PMID:24974133

  13. Novel denture-cleaning system based on hydroxyl radical disinfection.

    PubMed

    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. PMID:22720289

  14. Use of a complete denture as a radiation carrier

    SciTech Connect

    Herring, H.W. Jr.; Greene, P.E.

    1983-06-01

    When surgical resection of intraoral neoplasms is contraindicated, treatment by surface mold irradiation may be used. Success or failure of this mode of treatment may depend on the fabrication of a surface mold that can deliver the prescribed amount of therapeutic radiation in the desired amount of time. A technique for modification of an existing complete denture prosthesis for use as a surface mold has been described. Patient cooperation is essential for successful use of this modified prosthesis.

  15. Cytocompatible antifungal acrylic resin containing silver nanoparticles for dentures

    PubMed Central

    Acosta-Torres, Laura Susana; Mendieta, Irasema; Nuñez-Anita, Rosa Elvira; Cajero-Juárez, Marcos; Castaño, Víctor M

    2012-01-01

    Background Inhibition of Candida albicans on denture resins could play a significant role in preventing the development of denture stomatitis. The safety of a new dental material with antifungal properties was analyzed in this work. Methods Poly(methyl methacrylate) [PMMA] discs and PMMA-silver nanoparticle discs were formulated, with the commercial acrylic resin, Nature-CrylTM, used as a control. Silver nanoparticles were synthesized and characterized by ultraviolet-visible spectroscopy, dispersive Raman spectroscopy, and transmission electron microscopy. The antifungal effect was assessed using a luminescent microbial cell viability assay. Biocompatibility tests were carried out using NIH-3T3 mouse embryonic fibroblasts and a Jurkat human lymphocyte cell line. Cells were cultured for 24 or 72 hours in the presence or absence of the polymer formulations and analyzed using three different tests, ie, cellular viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell proliferation by enzyme-linked immunosorbent assay BrdU, and genomic DNA damage (Comet assay). Finally, the samples were evaluated mechanically, and the polymer-bearing silver nanoparticles were analyzed microscopically to evaluate dispersion of the nanoparticles. Results The results show that PMMA-silver nanoparticle discs significantly reduce adherence of C. albicans and do not affect metabolism or proliferation. They also appear not to cause genotoxic damage to cells. Conclusion The present work has developed a new biocompatible antifungal PMMA denture base material. PMID:22969297

  16. Antimicrobial efficacy of denture adhesives on some oral malodor-related microbes.

    PubMed

    Polyzois, Gregory; Stefaniotis, Theodoros; Papaparaskevas, Joseph; Donta, Catherine

    2013-01-01

    The objective of the study was to determine the antimicrobial efficacy of three denture adhesives toward Streptococcus oralis, mutans, Prevotella oralis and Fusobacterium nucleatum. Adhesives used were Corega Ultra(®), Fixodent Pro Original(®) and Biotene(®) Denture Grip. For Streptococcus oralis and Streptococcus mutans, four tubes of Trypticase Soy Broth 10 mL and 1 g denture of adhesive were used. In addition four tubes of Trypticase Soy Broth 10 mL without any denture adhesive was employed as control. For Prevotella oralis and Fusobacterium nucleatum, four tubes of thioglycolate 10 mL and 1 g denture adhesive were used for each one, while four tubes of thioglycolate 10 mL without adhesive served as control. All samples were incubated for 48 h at 37°C. After 48 h, the number of colonies was counted and the mean was extracted as cfu/mL. The results were evaluated with ANOVA on ranked data and Tukey's post hoc test at ? = 0.05. Streptococcus oralis, mutans, Prevotella oralis and Fusobacterium nucleatum showed decreased number of colonies for each denture adhesive compared to the control. Under the conditions of this in vitro study, all the tested denture adhesives showed antimicrobial efficacy. However, in contrast to the hypothesis, there were differences among them. Corega Ultra(®) and Biotene(®) Denture Grip were more effective for all the tested oral malodor-related microbes than Fixodent Pro Original(®). PMID:22075753

  17. The influence of a complete lower denture destabilization on the pressure of the mucous membrane foundation.

    PubMed

    ?mudzki, Jaros?aw; Chladek, Grzegorz; Kasperski, Jacek

    2012-01-01

    The results of previous studies on the pressures beneath the mucous membrane-supported dentures are contrary to the prevailing pain sensations and discomfort reported in practice. In this work, a FEM analysis of large displacements was used for calculation of the contact stresses beneath a lower denture that accompany destabilization under the realistic oblique mastication forces and stabilization of a non-working flange at the balancing contacts. The pressure on the surface of a mucous membrane beneath a denture that was loaded in a stable manner with a vertical occlusal force of 100 N was lower than the pain threshold. It was even more surprising as the extremely unfavorable lower denture foundation conditions were selected for this analysis. The lateral mastication forces destabilized the denture by means of tilting it and reducing its supporting area. Significant pressures calculated for the destabilization are consistent with the clinically observed decrease or a complete lack of chewing efficiency in the cases of unfavorable foundation conditions. A fundamental importance of the balancing contacts for the chewing efficiency was confirmed quantitatively. A remarkable development which has been achieved in the modeling of the denture functioning conditions is crucial for further biomechanical investigations of the mucous membrane-supported dentures, as well as for the implant-retained dentures. PMID:23140418

  18. Modified functionally generated path technique for single complete denture against non-modified natural dentition

    PubMed Central

    Upadhyay, Snehal Rashmikant; Singh, Saumyendra V; Bhalla, Gaurav; Kumar, Lakshya; Singh, Balendra P

    2012-01-01

    Background A clinical report of a patient complaining of frequent fractures of her maxillary complete denture opposing dentulous mandibular arch is presented. Materials and Methods The patient was rehabilitated with a maxillary complete denture using modified functionally generated path technique to achieve harmonious occlusion between the complete denture and the natural dentition. Discussion Using the patient's own denture to record the functionally generated path made the technique much easier and also saved valuable chair-side time. Occlusal balancing in the trial denture bases gave us the flexibility to move the teeth slightly, or grind them in order to balance the occlusion. Summary and Conclusion Our modification of the functionally generated path technique resulted in successful rehabilitation of the patient without any fracture of the prosthesis in the 2-year follow-up, and has saved valuable chair-side time and laboratory effort.

  19. Custom Metal Occlusal Surface for Acrylic Resin Denture Teeth to Enhance Wear Resistance: A Case Report

    PubMed Central

    Shivji, Rizwan Ali; Kamble, Vaibhav D.; Khan, Mohd. Atif

    2012-01-01

    Wear of the occlusal surface of the denture is a known fact which leads to subsequent changes in jaw relation, vertical dimension, loss of aesthetics, aged looks, and decrease in masticatory efficiency. Treatment modalities includes, change of denture set after a regular interval of 4-5 years, use of wear resistant denture teeth that includes wear resistant resin or porcelain teeth, teeth with cast metal occlusal surface, and altering occlusal contact areas of denture teeth by use of silver amalgam fillings. A case report of a patient who had increased tendency of occlusal wear was treated with custom made metal occlusal surface of denture teeth to enhance wear resistance and to improve the masticatory efficiency. PMID:22997592

  20. Endoscopic removal of a denture with clasps impacted in the ileocecum.

    PubMed

    Abe, Koichiro; Miki, Atsushi; Okamura, Takayuki; Shimada, Ken; Yamamoto, Takatsugu; Aiso, Mitsuhiko; Tanaka, Atsushi; Kita, Hiroto; Kuyama, Yasushi; Takikawa, Hajime

    2014-12-01

    We report a case of endoscopic removal of a denture with clasps impacted in the ileocecum. The patient was a 63-year-old man hospitalized at another center with aspiration pneumonia. He had a history of cerebral bleeding, inflicted permanent damage with left hemiplegia, and dysphagia. Abdominal radiography for localization of a catheter in the femoral vein revealed a denture in the right lower quadrant of the abdomen. He was subclinical and could not recall when he might have swallowed the denture. The patient was brought by ambulance to our institution. Computed tomography showed a foreign body with the density of metal in the ileocecum without any severe complications such as obstruction or perforation. Following intestinal lavage from a nasogastric tube, we performed colonoscopy and successfully retrieved the denture. The patient showed no complications associated with endoscopic therapy and returned to the previous hospital 3 days after endoscopic removal of the denture. PMID:25425499

  1. 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

    PubMed Central

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

    2014-01-01

    Background: 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. Materials & Methods: 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. Results: 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. Conclusion: The Tensile and Shear bond strength values of denture soft reliners were significantly lower than denture hard reliners. How to cite the article: Lau M, Amarnath GS, Muddugangadhar BC, Swetha MU, Das KA. 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. J Int Oral Health 2014;6(2):55-61. PMID:24876703

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

    PubMed Central

    Dhamande, Mithilesh M.; Pakhan, Ashok J.; Thombare, Ram U.; Ghodpage, Shyam L.

    2012-01-01

    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. PMID:22919216

  3. Effectiveness of Photodynamic Therapy for the Inactivation of Candida spp. on Dentures: In Vitro Study

    PubMed Central

    Mima, Ewerton Garcia de Oliveira; Ribeiro, Daniela Garcia; Dovigo, Livia Nordi; Vergani, Carlos Eduardo; Bagnato, Vanderlei Salvador

    2011-01-01

    Abstract Objective: This in vitro study evaluated the effectiveness of photodynamic therapy (PDT) for the inactivation of different species of Candida on maxillary complete dentures. Background data: The treatment of denture stomatitis requires the inactivation of Candida spp. on dentures. PDT has been reported as an effective method for Candida inactivation. Methods: Reference strains of C. albicans, C. glabrata, C. tropicalis, C. dubliniensis and C. krusei were tested. Thirty-four dentures were fabricated in a standardized procedure and subjected to ethylene oxide sterilization. The dentures were individually inoculated with one of the strains and incubated at 37°C for 24?h. Dentures submitted to PDT (P+L+) were individually sprayed with 50?mg/L of Photogem® (PS) and, after 30?min, illuminated by LED light for 26?min (37.5?J/cm2). Additional dentures were treated only with PS (P+L-) or light (P-L+) or neither (P-L-). Samples of serial dilutions were spread on Sabouraud dextrose agar and incubated at 37°C for 48?h. The colonies were counted and the values of log (cfu/mL) were analyzed by Kruskall-Wallis and Dunn tests (p<0.05). Results: For all species of Candida, PDT resulted in significant reduction (p<0.05) of cfu/mL values from dentures when compared with P-L- (reductions from 1.73 to 3.99 log10). Significant differences (p<0.05), but lower reductions, were also observed for P+L- and P-L+when compared with P-L- for some species of Candida. Conclusions: PDT was an effective method for reducing Candida spp. on dentures. PMID:21916614

  4. Long-term results of telescopic crown retained dentures--a retrospective study.

    PubMed

    Eisenburger, M; Gray, G; Tschernitschek, H

    2000-09-01

    The clinical data for 250 telescopic crown retained dentures involving 617 abutment teeth preparations were collected and analysed in a retrospective study to ascertain the survival rate of the dentures and their abutment teeth. During the study period 10.6% of the abutment teeth had to be extracted. An increased number of telescopic crowns significantly improved the longevity of the prostheses and their associated abutment teeth in most denture designs, but this was not found to be the case with bilateral free-end saddle designs without an anterior bounded saddle. The use of more than four abutment teeth did not result in a higher survival rate. PMID:11307565

  5. Fibres reinforced dentures investigated with en-face optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Negrutiu, Meda L.; Sinescu, Cosmin; Hughes, Michael; Bradu, Adrian; Goguta, Luciana; Rominu, Mihai; Negru, Radu; Podoleanu, Adrian Gh.

    2008-04-01

    The complete dentures are currently made using different technologies. In order to avoid deficiencies of the prostheses made using the classical technique, several alternative procedures have been devised. In order to enhance the mechanical strength, complete denture bases are reinforced with fibres. Their material and structure vary wildly, which makes the investigation difficult. In this study, optical coherence tomography (OCT) is evaluated as a possible non-invasive technique to assess the biomechanical behaviour of the reinforcing fibres. OCT images demonstrate structural defects between fibres and the acrylic material in all dentures bases investigated. We conclude that OCT can successfully be used as a noninvasive analysis method.

  6. The association between socioeconomic status, oral hygiene practice, denture stomatitis and oral status in elderly people living different residential homes.

    PubMed

    Evren, Buket Akalin; Uludamar, Altay; I?eri, Ufuk; Ozkan, Yasemin Kulak

    2011-01-01

    Oral hygiene practices and denture status of elderly people living in residential homes are different depending on the type of residential homes. In this study the elderly people living in three different residential homes were investigated for this purpose. A total of 269 subjects, 119 males (mean age 73.9±8.8) and 150 females (mean age 78.5±7.2) were involved in this study. All subjects were interviewed and clinically examined. Age, sex, educational status, financial status, general health, dental visiting, overnight denture wearing, brushing habits and frequency were recorded using a structured questionnaire. The prevalence of edentulism, the presence and type of dental prostheses, denture cleanliness and the presence of denture stomatitis were evaluated. Forty-one percent of subjects were non-educated. Fifty-one percent of subjects had low income. The majority of people (66.6%) were edentulous. Among the edentulous subjects 32% had full denture and 16% had no denture. Forty three percent of the subjects reported cleaning their dentures with water and 40% with a toothbrush only. Denture hygiene was good for 14% of the subjects. Denture stomatitis was observed in 44% of the subjects wearing dentures. There was statistically significant difference between residential homes and educational status, level of income, dental visiting, denture status, brushing methods and brushing frequency (p<0.001). A positive relationship was observed between poor denture hygiene habits and the presence of denture-related stomatitis. The most important need within the residents of the residential home was the enhancement of oral care social insurance. PMID:21269712

  7. In vitro testing of a denture cleaning method using ozone.

    PubMed

    Oizumi, M; Suzuki, T; Uchida, M; Furuya, J; Okamoto, Y

    1998-06-01

    The purpose of this study was to compare the microbicidal effect of gaseous ozone with that of ozonated water in order to determine its usefulness as a method for disinfecting dentures. Although a large number of research studies have been done on the bactericidal effect of ozone, little is known about its microbicidal effects on oral microorganisms. Therefore, we tested the effect of ozone on three standard strains of oral microorganisms: Streptococcus mutans (strain IID 973), Staphylococcus aureus (strain 209-P), and Candida albicans (strain LAM 14322). When the gaseous ozone injection method was used, the numbers of cells of all three strains decreased to 1/10(5) at 1 min, and by 3 min they were below the detection limit. Thus, the microbicidal effect of gaseous ozone was ascertained in a short time. In contrast, when ozonated water at 1 ppm and 3 ppm was used, C. albicans decreased to 1/10. A 700 mg/h ozone production level was needed to prepare 1 ppm ozonated water, whereas 20 mg/h of ozone was required by the gaseous ozone generator. These findings indicate that direct exposure to gaseous ozone seems to be a more effective microbicide compared with ozonated water, and that gaseous ozone can be clinically useful for disinfection of dentures. PMID:11186199

  8. Bactericidal efficacy of glycine-type amphoteric surfactant as a denture cleaner and its influence on properties of denture base resins.

    PubMed

    Hashiguchi, Makiko; Nishi, Yasuhiro; Kanie, Takahito; Ban, Seiji; Nagaoka, Eiichi

    2009-05-01

    The bactericidal efficacy of 1.00-4.50% glycine-type amphoteric surfactant (Gly) was evaluated by measuring its microorganism removal rate in denture plaque. Physical and mechanical properties such as surface roughness, color difference, and bending strength of two different denture base resins were determined before and after cleaning in Gly solutions, a commercial denture cleaner, and tap water. The microorganism removal rates of all the Gly solutions were higher than those of a commercial enzymatic denture cleaner (Polident) (p>0.05). The removal rate of Candida spp. by Polident was not significantly different from the removal rate using water. Changes in the surface roughness and color difference among the specimens were slight. There were no significant differences in the bending strengths of the two resins for all concentrations of Gly solution (p>0.05). These results suggested that glycine-type amphoteric surfactant solution may be effective as a denture cleaner in conjunction with an ultrasonic cleaning device. PMID:19662730

  9. 21 CFR 872.3410 - Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3410 Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive. (a)...

  10. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3400 Karaya and sodium borate with or without acacia denture adhesive. (a)...

  11. 21 CFR 872.3450 - Ethylene oxide homopolymer and/or karaya denture adhesive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3450 Ethylene oxide homopolymer and/or karaya denture adhesive. (a) Identification....

  12. 21 CFR 872.3410 - Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3410 Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive. (a)...

  13. 21 CFR 872.3450 - Ethylene oxide homopolymer and/or karaya denture adhesive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3450 Ethylene oxide homopolymer and/or karaya denture adhesive. (a) Identification....

  14. 21 CFR 872.3410 - Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3410 Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive. (a)...

  15. 21 CFR 872.3420 - Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3420 Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive. (a)...

  16. 21 CFR 872.3450 - Ethylene oxide homopolymer and/or karaya denture adhesive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3450 Ethylene oxide homopolymer and/or karaya denture adhesive. (a) Identification....

  17. 21 CFR 872.3450 - Ethylene oxide homopolymer and/or karaya denture adhesive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3450 Ethylene oxide homopolymer and/or karaya denture adhesive. (a) Identification....

  18. Peel strength of denture liner to PMMA and polyamide: laser versus air-abrasion

    PubMed Central

    Bagis, Bora; Özcan, Mutlu; Durkan, Rukiye; Turgut, Sedanur; Ates, Sabit Melih

    2013-01-01

    PURPOSE This study investigated the effect of laser parameters and air-abrasion on the peel strength of silicon-based soft denture liner to different denture resins. MATERIALS AND METHODS Specimens (N=180) were prepared out of three different denture base resins (Rodex, cross-linked denture base acrylic resin; Paladent, heat-cured acrylic resin; Deflex, Polyamide resin) (75 mm × 25 mm × 3 mm). A silicon-based soft denture liner (Molloplast B) was applied to the denture resins after the following conditioning methods: a) Air-abrasion (50 µm), b) Er,Cr:YSGG laser (Waterlase MD Turbo, Biolase Technology) at 2 W-20 Hz, c) Er,Cr:YSGG laser at 2 W-30 Hz, d) Er,Cr:YSGG laser at 3 W-20 Hz, e) Er,Cr:YSGG laser at 3 W-30 Hz. Non-conditioned group acted as the control group. Peel test was performed in a universal testing machine. Failure modes were evaluated visually. Data were analyzed using two-way ANOVA and Tukey's test (?=.05). RESULTS Denture liner tested showed increased peel strength after laser treatment with different parameters (3.9±0.4 - 5.58±0.6 MPa) compared to the control (3.64±0.5 - 4.58±0.5 MPa) and air-abraded groups (3.1±0.6 - 4.46±0.3 MPa), but the results were not statistically significant except for Paladent, with the pretreatment of Er,Cr:YSGG laser at 3 W-20 Hz. Polyamide resin after air-abrasion showed significantly lower peel strength than those of other groups (3.1±0.6 MPa). CONCLUSION Heat-cured acrylic resin, PMMA, may benefit from Er,Cr:YSGG laser treatment at 3 W-20 Hz irradiation. Air-abrasion of polyamide resins should be avoided not to impair their peel bond strengths to silicon-based soft denture liners. PMID:24049570

  19. Bond of acrylic teeth to different denture base resins after various surface-conditioning methods.

    PubMed

    Lang, Reinhold; Kolbeck, Carola; Bergmann, Rainer; Handel, Gerhard; Rosentritt, Martin

    2012-02-01

    The study examined the bond between different denture base resins and highly cross-linked acrylic denture teeth with different base surface-conditioning methods. One hundred fifty highly cross-linked resin denture teeth (SR-Antaris, No. 11, Ivoclar-Vivadent, FL) were divided into five groups with different surface-conditioning methods of the base surfaces of the teeth (C = control, no surface conditioning, MM = application of methyl methacrylate monomer, SB = sand blasting, SBB = sand blasting + bonding agent, TSS = tribochemical silica coating + silanization). Teeth were bonded to either a cold-cured denture base resin (ProBase Cold, Ivoclar-Vivadent, FL) or heat-cured denture base resins (SR Ivocap Plus, Ivoclar-Vivadent, FL and Lucitone 199, Dentsply, USA). After 24 h of storage in distilled water, compressive load was applied at 90° on the palatal surface of each tooth until fracture. Median failure load ranged between 103 and 257 N for Probase Cold groups, 91 to 261 N for Lucitone 199, and 149 to 320 N for SR Ivocap Plus. For Probase Cold, significant highest failure loads resulted when teeth were treated with SB, SBB, or TSS. For Lucitone 199, significant highest failure loads has been found with MM and TSS treatment. For SR Ivocap Plus, highest failure loads resulted using SBB and TSS. Conditioning of the base surfaces of the teeth prior to denture base processing is highly recommended. Tooth bond is significantly affected by the surface-conditioning method and applied denture base resin. Tribochemical silica coating + silanization method can be recommended for pre-treatment of teeth applying either heat-cured or cold-cured denture base resin. PMID:21181215

  20. Tensile bond strength of four denture resins to porcelain teeth with different surface treatment

    PubMed Central

    Powers, John

    2013-01-01

    PURPOSE This study evaluated the bond strength between porcelain denture teeth (Bioblend 43D) and four different polymerized denture resins (Lucitone 199, Palapress, Acron MC, Triad) with and without a bonding agent and after four different types of surface treatment (polished, HF etched, sandblasted, air-abraded). MATERIALS AND METHODS Central incisor porcelain denture teeth were divided into 32 groups of 5 each. Tensile bond strength (MPa) was determined using a testing machine at crosshead speed of 0.5 mm/min. Mean and standard deviation are listed. Data were analyzed by two-way ANOVA. Means were compared by Tukey-Kramer intervals at 0.05 significance level. RESULTS All surface treatment increased bond strength compared to polished surface and the highest bond strength was found with Palapress resin with etched porcelain surface (8.1 MPa). Bonding agent improved the bond strength of all denture resins to porcelain teeth. Superior bonding was found with Palapress and air-abraded porcelain (39 MPa). CONCLUSION Resins with different curing methods affect the bond strength of porcelain teeth to denture bases. Superior bonding was found with auto-polymerized resin (Palapress). Application of ceramic primer and bonding agent to porcelain teeth with and without surface treatment will improve the bond strength of all denture resins to porcelain teeth. PMID:24353880

  1. Implant-supported denture rehabilitation on a hemimandibulectomized patient: a case report

    PubMed Central

    Carini, Fabrizio; Gatti, Giambattista; Saggese, Vito; Monai, Dario; Porcaro, Gianluca

    2012-01-01

    Summary Aim of the study the treatment of oral cancer requires different surgical approaches such as marginal or segmental mandibular resection in order to allow a safe removal of the neoplastic lesion. The aim of this work is to evaluate the efficacy of an implant-supported denture rehabilitation for restoring oral function and facial appearance on a hemimandibulectomized patient. Materials and methods the patient was a 64 years old man, hard smoker and moderate drinker. Due to a jaw neoplastic lesion, he underwent a hemimandibulectomy, followed by the insertion of 4 implant fixtures at the chin cap symphysis site. The denture rehabilitation consisted in an over-denture mounted onto a bar furnished by a condylar eminence in articulation with the glenoid fossa of the upper denture. Results this type of implant-supported denture rehabilitation allows the recovery of the masticatory function and the mandibular reposition with a satisfactory restoration of the proper facial symmetry and appearance. Conclusion in the edentulous patient implant-supported denture with artificial condyle allows the recovery of the masticatory function without the need of additional operations to re-establish the temporomandibular joint anatomy. It is currently considered as a low invasive technique with very low risk of side effects. PMID:23285319

  2. The impact of frenulum height on strains in maxillary denture bases

    PubMed Central

    Bilhan, Hakan; Baysal, Gokhan; Sunbuloglu, Emin; Bozdag, Ergun

    2013-01-01

    PURPOSE The midline fracture of maxillary complete dentures is a frequently encountered complication. The purpose of this study was to assess the effect of frenulum height on midline strains of maxillary complete dentures. MATERIALS AND METHODS A removable maxillary complete denture was fabricated and duplicated seven times. Four different labial frenulum heights were tested for stresses occurring on the palatal cameo surface. The strains were measured with strain gauges placed on 5 different locations and the stresses were calculated. To mimic occlusal forces bilaterally 100 N of load was applied from the premolar and molar region. RESULTS A statistically significant association between the height of the labial frenulum and the calculated stresses and strains was shown (P<.05) predominantly on the midline and especially on the incisive papilla. The results showed that stress on the anterior midline of the maxillary complete denture increases with a higher labial frenulum. CONCLUSION Within the limitations of this in vitro study, it can be concluded that the stress on the anterior midline of the maxillary complete denture increases with a higher labial frenulum. Surgical or mechanical precautions should be taken to prevent short-term failure of maxillary complete dentures due to stress concentration and low cycle fatigue tendency at the labial frenulum region. PMID:24353878

  3. Frenectomy for improvement of a problematic conventional maxillary complete denture in an elderly patient: a case report

    PubMed Central

    2011-01-01

    Maxillary labial and buccal frena are considered as normal anatomic structures in the oral cavity. However, they may exist intraorally as a thick broad fibrous attachment and/or become located near the crest of the residual ridge, thus interfering with proper denture border extension resulting in inferior denture stability, retention and overall patient satisfaction. This case report highlights the importance of clinical examination and treatment planning which may mandate preprosthetic surgery prior to fabrication of a new conventional complete denture. Adequate patient satisfaction with conventional complete dentures can be significantly increased after frenectomy. PMID:22259708

  4. Frenectomy for improvement of a problematic conventional maxillary complete denture in an elderly patient: a case report.

    PubMed

    Al Jabbari, Youssef S

    2011-12-01

    Maxillary labial and buccal frena are considered as normal anatomic structures in the oral cavity. However, they may exist intraorally as a thick broad fibrous attachment and/or become located near the crest of the residual ridge, thus interfering with proper denture border extension resulting in inferior denture stability, retention and overall patient satisfaction. This case report highlights the importance of clinical examination and treatment planning which may mandate preprosthetic surgery prior to fabrication of a new conventional complete denture. Adequate patient satisfaction with conventional complete dentures can be significantly increased after frenectomy. PMID:22259708

  5. Effect of various chemicals on the bond strength of acrylic tooth and denture base -An Invitro comparative study

    PubMed Central

    Krishna, V Pridhvi; Premalatha, Averneni; Babu, P Jithendra; Raju, D Srinivasa; Kumar, M Praveen; Rao, D Bheemalingeswara

    2014-01-01

    Background: Debonding of acrylic teeth from the denture base is a common problem. Certain clinical conditions like ridge prominence leads to excess trimming of acrylic teeth and base, resulting in a weak interface. The denture base polymer debonds adhesively in the region of the highly cross –linked matrix of the teeth. To compare the effect of different chemical surface treatments on the bond between cross-linked acrylic teeth and different types of denture base material. Materials & Methods: A total of 180 wax specimens were fabricated and divided into 3 groups: Heat-cure, high impact heat-cure, flexible denture base material bonded to acrylic teeth. Each group was further subdivided into 6 subgroups with 10 specimens each according to the surface treatment ofthe ridge lap area: control, monomer, acetone 99%, chloroform 99%, acrylic adhesive cyanoacrylate, ethyl acetate 99%. After processing, specimens were tested for bond strength using a universal testing machine. The resulting bond strengths were recorded, statistically analyzed and compared. Results: Among all the 3types of denture base resins, highimpact heat-cure denture base resin gave highest bond strength. There was no bonding of teeth with flexible denture base material. Chemical surface treatment of acrylic teeth with ethyl acetate gave highest bond strength followed by control, chloroform, acetone and cyanoacrylate groups. Conclusion: Among all the 3types of denture base materials, high-impact heat-cure denture base resin gave highest bond strength with ethyl acetate surface treatment. Simple and quick tooth chemical surface treatment with ethylacetate could be an effective option in decreasing bonding failures and also avoid repeated denture repairs improving patient satisfaction. How to cite the article: Krishna VP, Premalatha A, Babu PJ, Raju DS, Kumar MP, Rao DB. Effect of various chemicals on the bond strength of acrylic tooth and denture base -An In-vitro comparative study. J Int Oral Health 2014;6(1):100-5. PMID:24653612

  6. A randomized clinical trial comparing the efficacy of mandibular implant-supported overdentures and conventional dentures in diabetic patients. Part IV: Comparisons of dietary intake

    Microsoft Academic Search

    Michael O. Hamada; Neal R. Garrett; Eleni D. Roumanas; Krishan K. Kapur; Earl Freymiller; Thomas Han; Randy M. Diener; Tenglang Chen; Seymour Levin

    2001-01-01

    Statement of problem. It is unclear whether the replacement of conventional mandibular dentures with implant-supported overdentures alters the diet and thus improves the nutritional intake of edentulous persons.Purpose. The purpose of this study was to compare the pretreatment and posttreatment diets of edentulous diabetic patients who received new dentures with either a conventional complete mandibular denture (CD) or a mandibular

  7. Randomized clinical trial comparing the efficacy of mandibular implant-supported overdentures and conventional dentures in diabetic patients. Part III: Comparisons of patient satisfaction

    Microsoft Academic Search

    Krishan K. Kapur; Neal R. Garrett; Michael O. Hamada; Eleni D. Roumanas; Earl Freymiller; Thomas Han; Randy M. Diener; Seymour Levin; Weng Kee Wong

    1999-01-01

    Statement of problem. There is insufficient evidence to indicate the functional superiority of mandibular implant-supported overdentures to justify their use in edentulous patients. Purpose. This study compared the benefits perceived by patients who received a new maxillary denture and a mandibular conventional denture (CD) and an implant-supported overdenture (IOD). Method. New maxillary and mandibular dentures were delivered to 89 diabetic

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

    PubMed Central

    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 (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. RESULTS 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. CONCLUSION 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. PMID:25006385

  9. [The clinical manifestations of the electrochemical processes due to the finishing treatment of dentures made from stainless steel].

    PubMed

    Gozhi?, A G; Sagatelian, G R; Gozhaia, L D; Bol'shakov, G V

    1998-01-01

    The authors propose to treat stainless steel dentures by grinding on organosilicon binding followed by 2 polishing procedures: with diamond paste and paste based on ultradispersed aluminum oxide powder. This technology improves the corrosion resistance of dentures and eliminates signs of diseases caused by electrochemical processes in the oral cavity more effectively than basic technology (vulcanite grinding and polishing with GOI paste). PMID:9643115

  10. Flexural strength of heat-polymerized polymethyl methacrylate denture resin reinforced with glass, aramid, or nylon fibers

    Microsoft Academic Search

    Jacob John; Shivaputrappa A. Gangadhar; Ila Shah

    2001-01-01

    Statement of problem. Despite the favorable properties of conventional PMMA used as a denture base material, its fracture resistance could be improved. Purpose. This in vitro study was performed to determine whether the flexural strength of a commercially available, heat-polymerized acrylic denture base material could be improved through reinforcement with 3 types of fibers. Material and methods. Ten specimens of

  11. Risk management in clinical practice. Part 6a. Identifying and avoiding medico-legal risks in complete denture prosthetics

    Microsoft Academic Search

    J. F. McCord

    2010-01-01

    The provision of complete dentures is often perceived as a clinical 'black art' as it relies on a blend of clinical skill, scientific evidence and no little artistic interpretation. Coupled to this is a heavy reliance on patient ability to control their dentures in a muscular environment while, hopefully, coping with the various oral functions in addition to appearance. This

  12. IN VITRO WEAR RESISTANCE OF THREE TYPES OF POLYMETHYL METHACRYLATE DENTURE TEETH

    PubMed Central

    Reis, Katia Rodrigues; Bonfante, Gerson; Pegoraro, Luiz Fernando; Conti, Paulo Cesar Rodrigues; de Oliveira, Pedro Cesar Garcia; Kaizer, Osvaldo Bazzan

    2008-01-01

    The wear resistance of denture teeth is important to the longevity of removable prostheses of edentulous patients. The ability of denture teeth to maintain a stable occlusal relationship over time may be influenced by this property. The purpose of this in vitro study was to evaluate the wear resistance of polymethyl methacrylate (PMMA) denture teeth based on their chemical composition when opposed by a ceramic antagonist. The maxillary canines (n=10) of 3 PMMA denture teeth (Trubyte Biotone, cross-linked PMMA; Trilux, highly cross-linked IPN (interpenetrating polymer network)-PMMA; and Vivodent, highly cross-linked PMMA) were secured in an in vitro 2-body wear-testing apparatus that produced sliding contact of the specimens (4.5 cycles/s, sliding distance of 20 mm, under 37°C running water) against glazed or airborne particle abraded ceramic. Wear resistance was measured as height loss (mm) under 300 g (sliding force) after 100,000 cycles, using a digital measuring microscope. Mean values were analyzed by 2-way ANOVA and Tukey's test (?=0.05). The wear of Trubyte Biotone (0.93 ± 0.14 mm) was significantly higher than that of both other types of teeth tested against abraded ceramic (p<0.05). The Vivodent tooth (0.64 ± 0.17 mm) exhibited the best wear resistance among the denture teeth tested against airborne particle abraded ceramic. There were no statistically significant differences (p>0.05) in wear among the 3 denture teeth evaluated against glazed ceramic. Trilux and Vivodent teeth tested against either glazed or airborne particle abraded ceramic did not differ significantly from each other (p<0.05). All teeth showed significantly more wear against airborne particle abraded ceramic than against glazed ceramic (p<0.05). In conclusion, the three types of PMMA denture teeth presented significantly different wear resistance against the abraded ceramic. The high-strength PMMA denture teeth were more wear-resistant than the conventional PMMA denture tooth. PMID:19089214

  13. Oral tactile sensibility recorded in overdenture wearers with implants or natural roots: a comparative study. Part 2.

    PubMed

    Mericske-Stern, R

    1994-01-01

    The capacity of dentate subjects to discriminate the thickness of objects placed between the teeth seems to depend on receptors in the periodontal ligament and muscles. The compensatory mechanism of ankylotic implants for the function of missing periodontal ligaments is not yet known. To investigate this question in overdenture wearers, 26 patients with ITI implants and 20 patients with natural roots were selected. According to the experimental protocol, the discriminatory ability was recorded with 10 steel foils (thickness ranging from 10 to 100 microns) placed between the premolars. Each thickness was tested 10 times and the test subjects were required to distinguish whether foil was positioned between the teeth. A maximum of 100 correct or 100 incorrect answers was possible. The average number of incorrect answers was significantly higher in test subjects with implants. The 50% limit (ie, the tested thickness recorded with at least 5 wrong answers) was established, but no statistically significant difference was found. In both groups, the critical tactile threshold of perceived thickness was 30 to 40 microns, with 2 being the average number of incorrect assessments. When comparing the minimal thickness, which was recorded without incorrect assessment, a significantly lower threshold was observed on patients with natural roots. Thus, active tactile sensibility appears to depend on the receptors in the periodontal ligament. However, wearing of removable prostheses is a modifying factor and may influence the oral tactile sensibility for both groups. PMID:8150514

  14. A case with tumor of left parotid gland and denture stomatitis.

    PubMed

    Mercu?, Veronica; Iorgulescu, Daniel; Popescu, Sanda Mihaela; M?rg?ritescu, Claudiu; Mercu?, R?zvan; Cr?i?oiu, Monica Mihaela; Scrieciu, Monica

    2015-01-01

    The article discuss the case of an edentulous patient presented to the dental clinic for pain and burning sensation of oral mucosa and diagnosed subsequently with oxyphilic adenoma. A 58-year-old patient, with maxillary edentulism, treated with complete denture, presented to the Clinic of Prosthetic Dentistry of the Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, Romania, for pain of oral mucosa and bad stability of denture. The diagnosis of erythematous denture stomatitis as consequence of salivary flow reduction was establish after patient's clinical examination, and by unstimulated sialometry. Clinical exam suggested hyposalivation could be a consequence of a tumor situated at the level of the left parotid gland. The echography confirmed the diagnosis of left parotid gland tumor. The tumor was surgical removed and histopathological exam confirmed oxyphilic adenoma. Education of patient for wearing new denture while maintaining a strict oral hygiene and dealing with low salivary flow was the treatment for denture stomatitis. General dentist has an important role in finding and diagnosing patients with systemic diseases, especially salivary tumors. PMID:25826511

  15. Physical Properties of Denture Base Resins Potentially Resistant to Candida Adhesion

    PubMed Central

    Dhir, Gunjan; Berzins, David W.; Dhuru, Virendra B.; Periathamby, A. Raj; Dentino, Andrew

    2008-01-01

    Purpose The addition of anionic charge on denture base resins has been shown to inhibit Candida albicans adhesion and to facilitate adsorption of salivary defense molecules. The aim of this study was to evaluate the physical properties of a modified denture base resin for denture fabrication. Materials and Methods Specimens made from heat polymerizing resin Lucitone 199 were used as the control group. The two experimental groups, E-10 and E-20, had 10% and 20%, respectively, of the monomer substituted with an experimental phosphate-containing monomer. Flexural strength and modulus, water sorption, solubility, and color stability tests were conducted to ensure compliance with ADA specification No. 12. Water diffusion coefficient into the resins and stainability were also assessed. ANOVA and Scheffe tests were performed for statistical significance. Results There was an overall decline in all properties with the addition of the experimental phosphate compound. The flexural strength and modulus, water sorption and solubility for E-10, as well as the control were, however, within the ADA specifications. The diffusion coefficients were significantly different (p < 0.05) for the three groups. Staining and color specimens showed no significant difference (p > 0.05) among the three groups. Conclusions Within the limitations of this study, the physical properties of the phosphate denture base resin at 10% should be suitable for denture fabrication based on the properties assessed. PMID:17672838

  16. Fatigue Life of Cast Titanium Alloys Under Simulated Denture Framework Displacements

    NASA Astrophysics Data System (ADS)

    Koike, Mari; Chan, Kwai S.; Hummel, Susan K.; Mason, Robert L.; Okabe, Toru

    2013-02-01

    The objective of the study was to evaluate the hypothesis that the mechanical properties and fatigue behavior of removable partial dentures (RPD) made from cast titanium alloys can be improved by alloying with low-cost, low-melting elements such as Cu, Al, and Fe using commercially pure Ti (CP-Ti) and Ti-6Al-4V as controls. RPD specimens in the form of rest-shaped, clasp, rectangular-shaped specimens and round-bar tensile specimens were cast using an experimental Ti-5Al-5Cu alloy, Ti-5Al-1Fe, and Ti-1Fe in an Al2O3-based investment with a centrifugal-casting machine. The mechanical properties of the alloys were determined by performing tensile tests under a controlled displacement rate. The fatigue life of the RPD specimens was tested by the three-point bending in an MTS testing machine under a cyclic displacement of 0.5 mm. Fatigue tests were performed at 10 Hz at ambient temperature until the specimens failed into two pieces. The tensile data were statistically analyzed using one-way ANOVA (? = 0.05) and the fatigue life data were analyzed using the Kaplan-Meier survival analysis (? = 0.05). The experimental Ti-5Al-5Cu alloy showed a significantly higher average fatigue life than that of either CP-Ti or Ti-5Al-1Fe alloy ( p < 0.05). SEM fractography showed that the fatigue cracks initiated from surface grains, surface pores, or hard particles in surface grains instead of the internal casting pores. Among the alloys tested, the Ti-5Al-5Cu alloy exhibited favorable results in fabricating dental appliances with an excellent fatigue behavior compared with other commercial alloys.

  17. Mechanical evaluation and fem analysis of stress in fixed partial dentures zirconium-ceramic

    PubMed Central

    CARDELLI, P.L.; VERTUCCI, V.; BALESTRA, F.; MONTANI, M.; ARCURI, C.

    2013-01-01

    SUMMARY Objective. Over the last several years, the Finite Element Analysis (FEM) has been widely recognized as a reference method in different fields of study, to simulate the distribution of mechanical stress, in order to evaluate the relative distribution of loads of different nature. The aim of this study is to investigate through the FEM analysis the stress distribution in fixed prostheses that have a core in Zirconia and a ceramic veneer supported by implants. Materials and methods. In this work we investigated the mechanical flexural strength of a ceramic material (Noritake®) and a of zirconium framework (Zircodent®) and the effects of the manufacturing processes of the material commonly performed during the production of fixed prostheses with CAD/CAM technology. Specifically three point bending mechanical tests were performed (three-point-bending) (1–3), using a machine from Test Equipment Instron 5566®, on two structures in zirconium framework-ceramic (structures supported by two implant abutments with pontic elements 1 and 2). A further in-depth analysis on the mechanical behavior in flexure of the specimens was conducted carrying out FEM studies in order to compare analog and digital data. Results. The analysis of the data obtained showed that the stresses are distributed in a different way according to the intrinsic elasticity of the structure. The analysis of FPD with four elements, the stresses are mainly concentrated on the surface of the load, while, in the FPD of three elements, much more rigid, the stresses are concentrated near the inner margins of the abutments. The concentration of many stresses in this point could be correlated to chipping (4) that is found in the outer edges of the structure, as a direct result of the ceramic brittleness which opposes the resilience of the structure subjected to bending. Conclusions. The analysis of the UY linear displacement confirms previous data, showing, in a numerical way, that the presence of the ceramic is related to the lowering of the structure. So, the reference values are those of the linear lowering obtained in the Mechanical Test and in our FEM analysis. zirconium framework with four elements 4,227 10?2mm.zirconium framework with ceramic structure with four elements 2,266 10?2 mm.That suggests that the presence of ceramics halves the flexion capabilities of the prosthetic materials. PMID:24772262

  18. A study on the fracture strength of collarless metal-ceramic fixed partial dentures

    PubMed Central

    Yoon, Jong-Wook; Kim, Sung-Hun; Lee, Jai-Bong; Han, Jung-Suk

    2010-01-01

    PURPOSE The objective of this study was to evaluate fracture strength of collarless metal-ceramic FPDs according to their metal coping designs. MATERIALS AND METHODS Four different facial margin design groups were investigated. Group A was a coping with a thin facial metal collar, group B was a collarless coping with its facial metal to the shoulder, group C was a collarless coping with its facial metal 1 mm short of the shoulder, and group D was a collarless coping with its facial metal 2 mm short of the shoulder. Fifteen 3-unit collarless metal-ceramic FPDs were fabricated in each group. Finished FPDs were cemented to PBT (Polybutylene terephthalate) dies with resin cement. The fracture strength test was carried out using universal testing machine (Instron 4465, Instron Co., Norwood MA, USA) at a cross head speed of 0.5 mm/min. Aluminum foil folded to about 1 mm of thickness was inserted between the plunger tip and the incisal edge of the pontic. Vertical load was applied until catastrophic porcelain fracture occurred. RESULTS The greater the bulk of unsupported facial shoulder porcelain was, the lower the fracture strength became. However, there were no significant differences between experimental groups (P > .05). CONCLUSION All groups of collarless metal-ceramic FPDs had higher fracture strength than maximum incisive biting force. Modified collarless metal-ceramic FPD can be an alternative to all-ceramic FPDs in clinical situations. PMID:21264192

  19. Quick response code in acrylic denture: will it respond when needed?

    PubMed

    Ragavendra, Thayappa Raju; Mhaske, Shubhangi; Gouraha, Abhishek; Yuwanathi, Monal; Kamath, Kavitha P; Saawarn, Swati; Kasetty, Sowmya

    2014-03-01

    Use of acids and other caustic substances in destroying the human body to avoid personal identification is drawing great deal of attention in recent times. With rapid industrial growth, incidence of industrial disasters has increased. In an event of chemical industry disaster, human identification can become a challenge. Embedding bar codes and other electronic means for identification in denture have proved to be a novel innovation in identification of edentulous patients. However, the validity of this method in events of chemical extremes has not been assessed. Hence, the study was undertaken to know the effect of different acids on dentures embedded with quick response codes. Results of this study indicate that simple bar code can be readable up to 33 h after acid treatment. With minimal armamentarium, bar code can be generated incorporating large data into it, providing it to be a cheap and reliable means of denture identification. PMID:24745081

  20. The geriatric patient: one- or two-visit complete denture construction technique. Part 1.

    PubMed

    Cinotti, W R; Grieder, A; Biber, C L

    1989-01-01

    The next two articles will discuss the construction of quality complete dentures in one- or two-patient appointments. Material and techniques are presented for controlling costs by reducing laboratory expenses and dentist chair time. A block unit of 12 to 14 attached flat plane acrylic teeth, light cured denture base materials and modified techniques which incorporate multiple procedures are introduced. The procedure will be divided into two segments and described in two articles. The initial article will carry the technique through the completion of the maxillo-mandibular relations and articulation for the casts. The second section, described in the second article, will encompass the set-up of the teeth, try-in of the set-up, processing of the dentures and insertion of the case. PMID:2700369

  1. Comparison of denture base resin reinforced with polyaromatic polyamide fibers of different orientations.

    PubMed

    Yu, Sang-Hui; Ahn, Dae-Hyung; Park, Ji-Su; Chung, Yong Sik; Han, In-Sik; Lim, Jung-Seop; Oh, Seunghan; Oda, Yutaka; Bae, Ji-Myung

    2013-01-01

    The aim of this study was to evaluate the effect of reinforcing polyaromatic polyamide (aramid) fibers with various orientations on the flexural properties of denture base resin. Aramid fibers with four orientations of unidirectional, woven, non-woven and paper-type were pre-impregnated and placed at the bottom of a specimen mold. Heat-polymerized denture base resin was packed over the fibers and polymerized. A three-point bending test was performed using a universal testing machine at a crosshead speed of 5 mm/min. The flexural strengths and flexural moduli of the unidirectional and woven groups were significantly higher than those of the control and other experimental groups.For the flexural moduli, all experimental groups showed significantly higher reinforcing effects than the control group. In conclusion, the unidirectional group located perpendicular to the direction of the load was most effective in reinforcing the denture base resin, followed by the woven group. PMID:23538771

  2. A mathematical derivation to prove reduced denture retention in v shaped palate.

    PubMed

    Mathew, Liji; Unni, K N; Vijayakumar

    2014-06-01

    The impact of oral health on the quality of life of older individuals have significantly increased over the last few decades. Edentulism substantially affect oral and general health and overall quality of life. Complete denture retention is the resistance to displacement of the denture base away from the ridge which is the main source of psychological comfort for the patient. Special retention problems are seen in patients exhibiting highly tapered steep palatal vault. In these cases a metal base or subsequent bench cure reline procedure would be incorporated into the initial treatment plan. In this article, we have derived a mathematical proof for the clinical experience that reduction in the palatal angle, results in lesser denture retention. PMID:24757354

  3. Abrasiveness of conventional and specific denture-cleansing dentifrices.

    PubMed

    Sorgini, Danilo Balero; Silva-Lovato, Claudia Helena da; de Souza, Raphael Freitas; Davi, Letícia Resende; Paranhos, Helena de Freitas Oliveira

    2012-01-01

    This study analyzed the weight loss and surface roughness caused in Plexiglass specimens by conventional dentifrices (Sorriso, Colgate and Close Up) and specific dentifrices used for cleaning of dentures (Corega and Dentu Creme). Plexiglass specimens were divided into 6 groups (n=6) including: a control (distilled water - DW) and experimental groups. Brushing was performed in a toothbrushing machine with a soft brush and a dentifrice suspension and DW according to different brushing times (50, 100, 200 and 250 min -18,000, 36,000, 72,000 and 90,000 cycles, respectively, calculated to correspond to 1, 2, 4 and 5 years of regular brushing). The results of weight loss and surface roughness were analyzed by ANOVA and Tukey's test at 5% significance level. In all tested times, the effect of DW was insignificant. Dentifrices differed significantly from DW in the initial period. Corega dentifrice caused greater mass loss in all studied times, followed by Close Up. Dentifrices resulted in a surface roughness similar to the DW at 50 min. In the other times, Sorriso, Colgate and Corega caused more surface roughness than DW. In conclusion, specific dentifrices caused larger mass loss and lower surface roughness as conventional dentifrice. PMID:22666774

  4. Physical Properties of Polyamide-12 versus PMMA Denture Base Material

    PubMed Central

    Wieckiewicz, Mieszko; Richter, Gert; Boening, Klaus W.

    2014-01-01

    Objectives. Polyamide-12 (PA) is a flexible material suited for denture bases and clasping. This study investigated its potential aging effects with a focus on surface roughness, color stability, and elasticity. Methods. PA specimens (Valplast) of 40 × 10 × 2?mm and equally measuring PMMA specimens (Palapress) as control were fabricated. Color changes after storage in air, water, coffee, and red wine (n = 10) were measured using the CIE L*a*b* color specification. Elasticity after thermocycling (1000, 3000, and 7000 cycles,??n = 15) was measured by three-point bending testing. Mean surface roughness (Ra) was determined after storage in the liquids mentioned above and thermocycling (n = 10). Results. Tukey's HSD test (P < 0.05) revealed statistically significant color changes of PA in red wine (?E = 4.27 after 12 days, ?E = 6.90 after 12 days) and coffee (?E = 3.93 after 36 days) but no color changes in PMMA. Elastic modulus of PA was 845?MPa and not affected by thermocycling (Tukey's HSD test,??P > 0.81). Dry specimens showed significantly decreased elasticity (P < 0.001). Mean surface roughness (PA 0.20??m, PMMA 0.28??m) did not change significantly after thermocycling or storage (Mann-Whitney U-test,??0.16 < P < 0.65). Significance. PA exhibited a higher susceptibility to discoloration than PMMA. Neither surface roughness nor elasticity of PA was altered by artificial aging. PMID:24734225

  5. Association between dentures and the rate of falls in dementia

    PubMed Central

    Eshkoor, Sima Ataollahi; Hamid, Tengku Aizan; Nudin, Siti Sa’adiah Hassan; Mun, Chan Yoke

    2014-01-01

    Background Poor oral health, chronic diseases, functional decline, and low cognitive ability can increase the risk of falls in the elderly. Objectives The current study aimed to show the effects of oral health, diabetes mellitus (DM), hypertension (HT), heart disease, functional status, and sociodemographic factors on the risk of falls in elderly with dementia. Materials and methods The sample comprised 1,210 Malaysian elderly who were demented and noninstitutionalized. This study was a national cross-sectional survey entitled “Determinants of Health Status among Older Malaysians”. The effects of age, ethnicity, sex differences, marital status, educational level, oral health, DM, HT, heart disease, and functional status on the risk of falls were evaluated. The multiple logistic regression model was used to estimate the effects of contributing variables on the risk of falls in samples. Results The prevalence of falls was approximately 17% in subjects. It was found that age (odds ratio [OR] 1.02), non-Malay ethnicity (OR 1.66), heart disease (OR 1.92), and functional decline (OR 1.58) significantly increased the risk of falls in respondents (P<0.05). Furthermore, having teeth (OR 0.59) and dentures (OR 0.66) significantly decreased the rate of falls (P<0.05). Conclusion It was concluded that age, non-Malay ethnicity, functional decline, heart disease, and oral health significantly affected falls in dementia. PMID:25018658

  6. Plasticizers in denture soft-lining materials: leaching and biodegradation.

    PubMed

    Munksgaard, E Christian

    2005-04-01

    The leaching from soft lining materials into an aqueous buffer with the same esterase activity as that of saliva was compared to leaching into buffer without esterase activity. The buffer contained 0.1% non-ionic detergent, giving the medium a capacity to dissolve phthalates to the same degree as saliva. The hypothesis that esterase in the immersion medium will increase the rate of diffusion of plasticizers from denture soft-lining material was confirmed by the results. The average leaching of phthalates from 5.5 g of one of the materials was 4.5 mg kg(-1) d(-1) within the first 2 d and 1.1 mg kg(-1) d(-1) within the first 28 d. These levels may be compared to a LOAEL (lowest observed adverse effect level) of 52 mg kg(-1). It is concluded that an esterase activity, equivalent to that in saliva, in the immersion medium for soft lining materials increased the rate of diffusion of plasticizer from the materials. The measured levels of phthalates leaching from these materials might in vivo only be slightly less than 1/10 of the LOAEL given above. PMID:15819824

  7. Hinged and sectional complete dentures for restricted mouth opening: A case report and review

    PubMed Central

    Sharma, Aditi; Arora, Pallak; Wazir, Sartaj Singh

    2013-01-01

    Restricted mouth opening is a definite prosthodontic hindrance to carry out treatment successfully. Restricted mouth opening can be due to many reasons such as microstomia, oral submucous fibrosis, some genetic disorder, and as a result of some surgical treatment. In the past, various techniques for prosthetic rehabilitation of limited oral opening have been tried such as surgeries, use of dynamic opening devices, magnetic devices, and modification of denture design. Here we present; a simplified technique and simple design for fabrication of maxillary hinged and mandibular hinged and sectional complete denture for a patient with restricted mouth opening due to oral submucous fibrosis. PMID:23853457

  8. Hinged and sectional complete dentures for restricted mouth opening: A case report and review.

    PubMed

    Sharma, Aditi; Arora, Pallak; Wazir, Sartaj Singh

    2013-01-01

    Restricted mouth opening is a definite prosthodontic hindrance to carry out treatment successfully. Restricted mouth opening can be due to many reasons such as microstomia, oral submucous fibrosis, some genetic disorder, and as a result of some surgical treatment. In the past, various techniques for prosthetic rehabilitation of limited oral opening have been tried such as surgeries, use of dynamic opening devices, magnetic devices, and modification of denture design. Here we present; a simplified technique and simple design for fabrication of maxillary hinged and mandibular hinged and sectional complete denture for a patient with restricted mouth opening due to oral submucous fibrosis. PMID:23853457

  9. Clinical Strategies for Complete Denture Rehabilitation in a Patient with Parkinson Disease and Reduced Neuromuscular Control

    PubMed Central

    Haralur, Satheesh B.

    2015-01-01

    The dentist has a large role in geriatric health care for the ever increasing elder population with associated physical and neurological disorders. The Parkinson disease is progressive neurological disorder with resting tremor, bradykinesia, akinesia, and postural instability. The psychological components of disease include depression, anxiety, and cognitive deficiency. Poor oral hygiene, increased susceptibility for dental caries, and periodontal diseases predispose them to early edentulism. The number of Parkinson affected patients visiting dental clinic seeking complete denture is growing. This case report explains the steps involved in the complete denture rehabilitation of Parkinson patient. The effective prosthesis will help in alleviating functional, aesthetic, and psychological disabilities of the patient. PMID:25737785

  10. The method of manufacture of nylon dental partially removable prosthesis using additive technologies

    NASA Astrophysics Data System (ADS)

    Kashapov, R. N.; Korobkina, A. I.; Platonov, E. V.; Saleeva, G. T.

    2014-12-01

    The article is devoted to the topic of creating new methods of dental prosthesis. The aim of this work is to investigate the possibility of using additive technology to create nylon prosthesis. As a result of experimental studies, was made a sample of nylon partially removable prosthesis using 3D printing has allowed to simplify, accelerate and reduce the coat of manufacturing high-precision nylon dentures.

  11. Dynamic viscoelastic properties of processed soft denture liners: Part II--Effect of aging.

    PubMed

    Wagner, W C; Kawano, F; Dootz, E R; Koran, A

    1995-09-01

    The proper functioning of soft denture liners depends to a great extent on their mechanical properties. As with many polymers these materials are affected by aging. Twelve soft denture liners were processed by a laboratory according to the manufacturers' directions. Five specimens of each material were tested without aging. Five additional specimens of each material were subjected to 900 hours of accelerated aging in a Weather-Ometer instrument. These were tested with a dynamic viscoelastometer at three frequencies and two temperatures, and data for 37 degrees C and 1 Hz was obtained. Two of the ethyl methacrylate resins demonstrated the largest increases in storage (E') and loss moduli (E") after aging. These materials also showed the greatest overall E' and E". One denture liner material exhibited 673% and 488% increases in E' and E", and other materials showed smaller increases. The effects of aging on the damping factor (tan delta) were varied and five materials showed increased tan delta. Only two ethyl methacrylate resins developed lower tan delta. All the silicone and polyphosphazine rubbers showed small changes after aging and had the lowest tan delta values. Significance of differences between materials and treatments was tested with ANOVA, Scheffé intervals, and t-tests at a = 0.05. The ethyl methacrylate soft denture liners were affected the most by accelerated aging, and the silicones and polyphosphazine were least affected. The ethyl methacrylate resins also had the greatest values of E', E", and tan delta after aging. PMID:7473285

  12. TensoDentar — Equipment for measuring the extraction force of removable dentures and palatal plates

    Microsoft Academic Search

    Dan Mihai Stejanescu; Alexandru-Titus Farcasiu; Mihaela Pauna

    2012-01-01

    The paper presents a complex measurement system — called TensoDentar — used for the evaluation of complete dentures and palatal plates dislodging forces. An original strain gauge force transducer and virtual instrumentation in NI and LabVIEW environment are used conforming with a rigorous clinical protocol to evaluate the efficiency of two surface treatments (sandblasting and, respectively, plasma treatment) on complete

  13. A one-appointment impression and centric relation record technique for compromised complete denture patients

    Microsoft Academic Search

    Izharul Haque Ansari

    1997-01-01

    This article describes a two-in-one modified custom tray and record block system that is recommended for compromised elderly patients. Custom trays, which are made on primary casts and formed from a patient's functionally corrected old dentures, are used to make final impressions and centric jaw relation records in one clinical appointment. The clinical visits are reduced without compromising the quality

  14. [Mathematical simulation of mechanical system abutment teeth--aramide thread adhesive bridge denture].

    PubMed

    Riakhovski?, A N; Banichuk, N V; Saurin, V V; Kuznetsova, E A

    2002-01-01

    A mathematical model of a new pontic design is developed. The final element analysis of the model proved the efficiency of the design. Effects on the denture length, abutment area cone angle, thread strain and height of location on abutment teeth, depending on the type and site of exercise, were studied. PMID:11889871

  15. Effect of immersion cleansing in color stability and hardness of soft denture reliners.

    PubMed

    Niarchou, Artemis; Ntala, Polyxeni; Pantopoulos, Antonis; Polyzois, Gregory; Frangou, Mary

    2012-03-01

    Hygienic care of removable prostheses is important, and denture cleansers selected must be efficient and maintain the physicomechanical properties of soft reliners. Microwave energy has been reported to increase the sanitation effectiveness of denture cleansers. The purpose of the study was to evaluate hardness and color stability of some visible light polymerized and autopolymerized soft reliners after exposure in different denture-cleansing treatments. Six soft denture reliners (2 autopolymerized silicones, 1 autopolymerized acrylic, and 3 visible light polymerized ones) were exposed to 4 cleansing treatments (Corega Whitening, Polident 5-Minute, Corega Whitening + microwaving, Polident 5-Minute + microwaving). Hardness was measured with a Shore A durometer, and color changes were evaluated by a tristimulus colorimeter. The results were subjected to 2-way analysis of variance and Scheffé test for post hoc comparisons at a confidence level of ? = 0.05. Sofreliner showed the smallest hardness change, and LightLiner the greatest. Versasoft and Sofreliner seem to have the lowest color change for every cleansing treatment examined, whereas LightLiner and Eversoft presented the greatest. Silicone-based materials demonstrated the smallest changes in both hardness and color, either when using water or with any of the other cleansing treatments. PMID:22421839

  16. Physiological reactions of the denture-bearing mucosa following mechanical stress

    NASA Astrophysics Data System (ADS)

    Niedermeier, Wilhelm; Gutmann, F.; Kessler, Manfred D.; Frank, K. H.

    1994-02-01

    The mucosa of the edentulous ridges and the hard palate is used to bear denture bases. While the etiology of mucosal disorders caused by material and microbiological factors is well known, the effects of mechanical stress on denture bearing mucosa are comparatively unexplored. To learn more about reactions of compensation against mechanical stress of the denture bearing mucosa we studied physiology of the tissues covering the alveolar ridge and the hard palate. We took non-invasive measurements of the concentration and oxygenation of hemoglobin in several places of the mucosa by using a micro-lightguide spectrophotometer (EMPHO). On this occasion the magnitude and duration of the force, the frequency of the loading and the interval of rest have been varied. The result was that the concentration of hemoglobin decreased significantly inside the mucosa when the denture bearing mucosa was stressed already by a slight but constant compression load. However, a total ischemia was not seen even in great mechanical loads. After the stress ended a reactive hyperemia took place spontaneously.

  17. Influence of inner circular sealing area impression method on the retention of complete dentures.

    PubMed

    Wang, Cun-Wei; Shao, Qi; Sun, Hui-Qiang; Mao, Meng-Yun; Zhang, Xin-Wei; Gong, Qi; Xiao, Guo-Ning

    2015-01-01

    The aims of the present study were to describe an impression method of "inner circular sealing area" and to evaluate the effect of the method on retention, aesthetics and comfort of complete dentures, which lack labial base for patients with maxillary protrusions. Three patients were subjected to the experiment, and two sets of complete maxillary dentures were made for each patient; the first set was made without labial base via an inner circular sealing area method (experimental group) and the second had an intact base that was made with conventional methods (control group). Retention force tests were implemented with a tensile strength assessment device to assess the retention and a visual analogue scale (VAS) was used to evaluate the comfort between the two groups. Results showed larger retention force, better aesthetics and more comfort in the experimental group. The improved two-step impression method formed an inner circular sealing area that prevented damage to the peripheral border seal effect of the denture caused by incomplete bases and obtained better denture retention. PMID:25831114

  18. One versus two implant-retained dentures: comparing biomechanics under oblique mastication forces.

    PubMed

    ?mudzki, Jaros?aw; Chladek, Grzegorz; Kasperski, Jacek; Dobrza?ski, Leszek A

    2013-05-01

    The results from clinical tests of single implant-retained dentures (SIDs) are quite promising. However, the biomechanics of SIDs are still insufficiently determined. The aim of the study was to compare the implant loads and pressures beneath one and two implant-retained dentures (TIDs) under oblique mastication forces. The finite element method was used to conduct a model analysis in order to compare loading of the denture attachment onto the implant that accompanies oblique mastication forces in the cases of SIDs and TIDs. The possibility of a denture detaching and sliding on the mucous membrane surface was simulated. The SID solution faced a more remarkable tilt in the direction of the mastication forces, a higher pressures on the mucous membrane surface, and higher implant loadings. The hingelike restraints in the TID favored utilization of the support in the posterior area. The higher pressure values for the SID can be confusing and could lead to inaccurate conclusions about the acceptability of the SID. In the TID, the same areas of the mucous membrane were persistently loaded, independent of the occlusal force direction. In contrast, in the SID the full freedom of rotational movement enhances alternating use of the mucous membrane. This finding explains the more frequent sores in the mucous membrane beneath the TID than beneath the SID. PMID:24231964

  19. Implant-retained dentures for full-arch rehabilitation: a case report comparing fixed and removable restorations.

    PubMed

    Zafiropoulos, Gregory-George; Hoffman, Oliver

    2011-01-01

    Dental implants as abutments for full-arch restorations are a well-documented treatment modality. This report presents a case in which the patient was treated initially with fixed restorations supported by either implants or natural teeth and subsequently treated with a removable implant/telescopic crown-supported overdenture. Advantages and disadvantages of each approach are described and discussed. While the fixed restoration resulted in a functionally satisfactory treatment outcome, the patient was displeased with the esthetic appearance. The main concern was the unnaturally long tooth shape necessary to compensate for the insufficient alveolar ridge height. Replacement of the existing restoration with an implant-supported removable overdenture led to a functionally and esthetically acceptable result. When deciding whether to use a fixed or removable implant-supported full-arch restoration, a multitude of factors must be considered. Due to the possible need for additional surgical steps to enhance the esthetic appearance surrounding fixed restorations, removable implant-supported partial dentures often are the better choice. PMID:21903551

  20. Advanced biomaterials used for a new telescopic retainer for removable dentures.

    PubMed

    Weigl, P; Lauer, H C

    2000-01-01

    Telescopic retainers with conical ceramic abutment crowns and electroplated gold copings define a new retainer for removable dentures exhibiting favorable tribological properties that could offer clinical advantages. The objective of this study was to evaluate the clinical effects of this retainer. To do so, a novel treatment modality was developed based on intraoral bonding of the copings to the framework in order to be able to realize, in a clinical setting, the retainer function based on a precision fit. A total of 32 patients wearing 33 dentures (16 mandibular, 17 maxillary; period of risk [months]: minimum = 3; maximum = 58; mean = 27.6), supported by 147 abutments (83 natural teeth, 64 implants) with ceramic abutment crowns (IPS Empress 1, IPS Empress 2, InCeram, Procera, CerAdapt; CeraBase) were followed at 6-month intervals. The ceramic abutment crowns showed low plaque accumulation (mean PI = 17.3%). The gingival tissues around natural abutments were generally free of inflammation; so was the mucosa around the implants (mean SBI = 4.9%). Denture adhesion and occlusion did not change, and there were no rocking movements. The mobility (as determined by Periotest) of 29 teeth was reduced in a highly significant manner within 6 months (t test, p < 0.001). Osseointegration was preserved for all implants. One abutment loosened. Six Empress 1 ceramic copings failed (94.6% Kaplan-Meier survival rate), and one abutment tooth was lost (99.2% survival rate). All patients reported problem-free handling, no rocking movements, and constant adhesion. The adhesive strength of one denture was too low at insertion. 94% of the patients experienced no problems with oral hygiene. The retainer examined has relevant clinical advantages and meets geriatric requirements for removable dentures. PMID:10898874

  1. Oral Crest Lengthening for Increasing Removable Denture Retention by Means of CO2 Laser

    PubMed Central

    Nammour, Samir; Gerges, Elie; Bou Tayeh, Rima; Zeinoun, Toni

    2014-01-01

    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. PMID:25383385

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

    PubMed

    Vieira, Ana Paula Coelho; Senna, Plínio Mendes; Silva, Wander José da; Del Bel Cury, Altair Antoninha

    2010-01-01

    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 (?; = 0.05). Results of cell count estimation showed significant differences in cleanliness among the treatments (p < 0.001), and it could be observed by SEM. However, no significant difference (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. PMID:20877973

  3. Effect of phosphate group addition on the properties of denture base resins

    PubMed Central

    Puri, Gaurav; Berzins, David W.; Dhuru, Virendra B.; Raj, Periathamby A.; Rambhia, Sameer K.; Dhir, Gunjan; Dentino, Andrew R.

    2009-01-01

    Statement of problem Acrylic resins are prone to microbial adherence, especially by Candida albicans. Surface-charged resins alter the ionic interaction between the denture resin and Candida hyphae, and these resins are being developed as a means to reduce microbial colonization on the denture surface. Purpose The purpose of this study was to investigate the physical and mechanical properties of phosphate-containing polymethyl methacrylate resins for their suitability as a denture material. Material and methods Using PMMA with cross-linker (Lucitone 199) as a control, 4 experimental groups containing various levels of phosphate with and without cross-linker were generated. The properties examined were impact strength, fracture toughness, wettability (contact angle), and resin bonding ability to denture teeth. Impact strength was tested in the Izod configuration (n=16), and fracture toughness (n=13) was measured using the single-edge notched bend test. Wettability was determined by calculating the contact angle of water on the material surface (n=12), while ISO 1567 was used for bonding ability (n=12). The data were analyzed by 1- and 2-way ANOVA (?=.05). Results A trend of increased hydrophilicity, as indicated by lower contact angle, was observed with increased concentrations of phosphate. With regard to the other properties, no significant differences were found when compared with the control acrylic resin. Conclusions No adverse physical effect due to the addition of a phosphate-containing monomer was found in the acrylic denture resins. Additional mechanical and physical properties, biocompatibility, and clinical efficacy studies are needed to confirm the in vivo anti-Candida activity of these novel resins. PMID:18922259

  4. Application of electrolyzed acid water to sterilization of denture base part 1. Examination of sterilization effects on resin plate.

    PubMed

    Nagamatsu, Y; Tajima, K; Kakigawa, H; Kozono, Y

    2001-06-01

    Bactericidal activities of electrolyzed strong and weak acid waters for acrylic denture base resin were evaluated in order to discuss the applicability of these waters for sterilization of denture base. Only 1-minute immersion in the electrolyzed strong or weak acid water could completely eliminate the attached bacteria, Staphylococcus aureus 209P, on the resin plate. When the resin was relined with tissue conditioner, 5-minute immersion or 1- to 2-minute ultrasonic cleaning reduced the number of the bacteria from 10(5)/cm2 level to 10(1)/cm2 and no surviving bacteria could be detected after 10-minute treatment. These findings suggest that both the electrolyzed strong and weak acid waters are well applicable to the disinfectant for acrylic denture base showing excellent bactericidal activities in a significantly shorter treatment as compared with the conventional denture cleaning. PMID:11523978

  5. [New use of pulse-oximeter as a prophylactic Stimulator to the wearer and a lifesaving tools for prevention of hypoxic mishaps].

    PubMed

    Morioka, Tohru; Terasaki, Hidenori

    2014-03-01

    Pulse-oximeter has been widely used for the clinical assessment of physical status of a patient and as an alarming tool of hypoxia to medical personnel at the bedside or in the observation center. However, it has never been used for direct stimulation of the wearer. We considered innovation of pulse-oximeter as a prophylactic alarm-oximeter for the wearer. If SPO2 goes down to unfavorable level, the alarm-oximeter starts to send signal through a control box to a stimulator, such as an electrical nerve stimulator, a cold thermal tip, or mechanical device like a vibrator or compressor. The dermal stimulator is usually fixed to the right or left wrist with a Velcro band. The control box is affixed to the wristband by using Velcro. The alarm may be sent to an earphone or speaker with a verbal command like "take a deep breath". Alarm-oximeter will be combined to an oxygen inhaler or mechanical ventilatory assist device, or a drug administration system through electric line or wireless transmitter to start or change its function before the arrival of medical personnel. It will prevent hypoxic mishaps during medical intervention or sleep apnea syndrome. It will be also applicable to stop snoring. PMID:24724452

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

    PubMed Central

    2014-01-01

    Background 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. Methods 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. Results 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?Denture/bridge use was significantly associated with high educational attainment in males and participating in social groups in females in the fully adjusted model (p?denture/bridge use and social capital. Conclusions 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. PMID:24894968

  7. The evaluation of some flexural properties of a denture base resin reinforced with various aesthetic fibers

    Microsoft Academic Search

    Orhan Murat Do?an; Giray Bolay?r; Selda Keskin; Arife Do?an; Bülent Bek

    2008-01-01

    This study was performed to determine whether some flexural properties of a denture base resin material could be improved\\u000a through reinforcement with five types of aesthetic fibers at 3% concentration by weight and in 2, 4, and 6 mm length. Five\\u000a specimens of similar dimensions were prepared for each of the test groups; base resin and the same resin with glass,

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

    PubMed Central

    Žilinskas, Juozas; Junevi?ius, Jonas; ?esaitis, K?stutis; Junevi?i?t?, Gabriel?

    2013-01-01

    Bakcground 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. Material/Methods 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. Results No statistically significant differences were found between the 3 test series. All 3 plates used in the study underwent statistically significant (p<0.05changed) – the reflection became poorer. The plates were most affected by the medium-bristle toothbrush with baking 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 – 3.89±0.07%. Conclusions 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. PMID:24326781

  9. Effect of high-pressure polymerization on mechanical properties of PMMA denture base resin.

    PubMed

    Murakami, Natsuko; Wakabayashi, Noriyuki; Matsushima, Rie; Kishida, Akio; Igarashi, Yoshimasa

    2013-04-01

    The aim of this study was to assess the effect of high-pressure polymerization on mechanical properties of denture base resin. A heat-curing denture base resin and an experimental PMMA were polymerized under 500MPa of pressure by means of an isostatic pressurization machine at 70°C for 24h to make rectangular specimens whose dimensions were 30mm×2mm×2mm. Each specimen was deflected on a three-point flexural test until either fracture occurred or the sample was loaded up to 8mm in deflection. The molecular weight of the PMMA without filler was analyzed using the high-speed liquid chromatography system. Increased ductility without fracture was shown in the specimens subjected to high pressure, while most of the control specimens (ambient pressure) fractured. The mean toughness of the PMMA specimens polymerized under the high pressure was significantly higher than the same material polymerized under ambient pressure (p<0.01). The high pressure groups of the denture resin and the PMMA revealed a significantly lower mean 0.2% yield stress, flexural strength, and elastic modulus than control groups (p<0.01). There were certain amounts of higher molecular weight polymers in the high pressure specimens than were present in the controls. The increased toughness shown in the PMMA polymerized under the high pressure was presumably attributed to the higher molecular weight produced by the pressure. The result suggests a potential application of the high-pressure polymerization to the development of PMMA-based denture resin with improved fracture resistance. PMID:23455166

  10. Morphology and properties of denture acrylic resins cured by microwave energy and conventional water bath

    Microsoft Academic Search

    C.-P. Lai; M.-H. Tsai; M. Chen; H.-S. Chang; H.-H. Tay

    2004-01-01

    Objectives. This study examined the influence of microwave energy levels on the morphology and properties of an impact resistant denture material poly(methyl methacrylate) with a thickness of 10 mm.Methods. A microwave flask containing two resin blocks was processed at 80, 160, 240, and 560W for 15, 10, 7, and 2 min, separately. Each Flask was then turned over, and cured

  11. [Foreign dentures and dental tourism--willingness-to-pay and factors influencing the demand for foreign dental prosthesis in Germany].

    PubMed

    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. PMID:20571980

  12. Photoelastic analysis to compare implant-retained and conventional obturator dentures

    NASA Astrophysics Data System (ADS)

    Goiato, Marcelo Coelho; Prado Ribeiro, Paula do; Pellizzer, Eduardo Piza; Pesqueira, Aldiéris Alves; Haddad, Marcela Filiè; dos Santos, Daniela Micheline; Moreno, Amália

    2012-06-01

    The use of photoelastic analysis contributes to the rehabilitation of patients with oral-sinus-nasal sequelae, which in turn affect important functions such as chewing, swallowing, and speech. The prosthetic rehabilitation with implant-retained dentures is a suitable treatment option. The purpose of this study was to verify, by using a photoelastic analysis, the stress distribution in implant-retained palatal obturator dentures (relined or not) associated with different attachment systems (O-ring, bar-clip, and bar-clip associated with distally placed O-rings). Two photoelastic models were obtained from an experimental maxillary cast presenting an oral-nasal communication. One model had two 13-mm length implants placed on the left region. A total of eight colorless maxillary obturators were fabricated and subsequently four of them were relined with soft silicone soft, and three had attachment systems associated. The assembly (model/attachment system/prosthesis) was positioned in a circular polariscope and a 100-N load was applied at 10 mm/s. The results showed that the denture relining influenced the distribution and amount of stress on the models. The O-ring group displayed the lowest stress levels, followed by bar-clip system associated with distally placed O-rings and bar-clip groups.

  13. Sublingual varices in relation to smoking, cardiovascular diseases, denture wearing, and consuming vitamin rich foods

    PubMed Central

    Al-Shayyab, Mohammad H.; Baqain, Zaid H.

    2015-01-01

    Objectives: To identify potential risk factors such as smoking, cardiovascular diseases (CVD), denture wearing, and consuming vitamin rich foods, and its relation to the development of sublingual varices (SLV). Methods: This cross-sectional observational study was conducted on patients who attended the Department of Dentistry at The University of Jordan Hospital, Amman, Jordan between February and May 2013. Clinical examinations and inspections of 391 patients (203 males and 188 females), 13-74 years of age were conducted to determine the presence of SLV. Sublingual varices were classified into 2 categories: grade 0 (few or none visible), and grade one (moderate or severe). Frequency distributions of both SLV and risk factors were obtained. Multiple logistic regression analysis and Chi-square test were used to analyze the influence of individual risk factors on the incidence of SLV. Results: There were 88 subjects (22.5%) who had SLV. In the multivariate logistic regression model, SLV were significantly associated with age (odds ratio [OR]: 2.27, p=0.008) with highest occurrences in the eighth decade of life, gender (OR: 2.74, p=0.001), smoking (OR: 2.93, p=0.002), denture wearing (OR: 2.03, p=0.044), and CVD (OR: 4.01, p=0.00). Conclusion: The presence of SLV could be indicative of some potential risk factors including old age, female gender, and denture wearing, and may alert the dental clinician to recognize underlying systemic conditions, particularly CVD. PMID:25737173

  14. Periodontal and prosthetic therapy in severely advanced periodontitis by the use of the crown sleeve coping telescope denture. A longitudinal case report

    Microsoft Academic Search

    Guey-Lin Hou; Chi-Cheng Tsai; Arnold S. Weisgold

    1997-01-01

    The crown and sleeve-coping (CSC) telescope denture is a removable prosthesis that is supported by both selectively retained teeth and the residual ridge or mucosa. Limited information regarding longitudinal studies of the CSC telescope denture has been reported as to the response of the abut- ments and their surrounding periodontal tissues to this type of design. The authors have documented

  15. Evaluation of the efficacy of titanium plates as denture markers under various heat sources and pressure - An in vitro study

    PubMed Central

    Srinivasan, Suganya; Chidhambaranathan, Ahila Singaravel; Balasubramanian, Muthukumar; Mony, Bejoy Mony Chidhambaram; Reddy, Ramesh J.

    2015-01-01

    Introduction: Denture Markers are used as one of the main identifying aid in mass disasters. Dental description of missing person in mass disasters plays a vital role in forensic research. Difficulties arise when the teeth are missing. In such situation the prosthodontic identification (ID) of replaced teeth becomes the priority. Till recently, there was no development of denture marker that could withstand massive fire accidents. Aim: To determine the use of titanium chips with identity code engraved on it as denture markers that could withstand high temperature and pressure. Materials and Methods: Wax patterns were fabricated with identity code moulded on a rubber stamp. It was invested and casted with titanium. Titanium chips were inserted into the polymethylmethacrylate (PMMA) block and subjected to various heat treatments. Results: There was no loss of identity when subjected to 1,500°C overnight but only residues left under pressure of 200 kg/cm3. Conclusion: The literature recommends the metallic denture markers in order to withstand the post morten assaults. Titanium denture markers could be a preferred option as it can withstand high temperatures under pressure also. PMID:25709322

  16. A comparative study of retention of complete denture base with different types of posterior palatal seals – an in vivo study

    PubMed Central

    Chandu, GS; Hema, BS; Mahajan, Harsh; Azad, Antriksh; Sharma, Ipsita; Azad, Anurag

    2014-01-01

    Aim To evaluate retention of complete denture base with different types of posterior palatal seals. Material and methods Ten male patients between the age group of 50 years to 60 years were selected for the study. After the primary and secondary impressions were taken, five casts were made including a cast without posterior palatal seal, a cast with single bead posterior palatal seal, a cast with double bead posterior palatal seal, a cast with butterfly shaped posterior palatal seal, and a cast with posterior palatal seal with low fusing compound by functional method. Results It was observed that retention increased up to 108% in the posterior palatal seal with low fusing compound with functional method and the posterior palatal seal that was obtained by using functional method provided greater retention than a denture base without posterior palatal seal. Conclusion It was concluded that the incorporation of a posterior palatal seal is important for obtaining optimum retention of the maxillary complete denture. PMID:25473314

  17. Influence of a new denture cleaning technique based on photolysis of H(2)O(2) the mechanical properties and color change of acrylic denture base resin.

    PubMed

    Nakahara, Tatsuro; Harada, Akio; Yamada, Yasutomo; Odashima, Yu; Nakamura, Keisuke; Inagaki, Ryoichi; Kanno, Taro; Sasaki, Keiichi; Niwano, Yoshimi

    2013-01-01

    The purpose of this study was to evaluate the influence of a disinfection technique based on photolysis of H2O2 on the mechanical properties and color change of acrylic denture base resin. Resin specimens were immersed in 1 M H2O2 irradiated with light-emitting diode (LED) light at 400 nm for 1 week. The immersion duration of 1 week (168 h) corresponded to performing approximately 500 times of 20-min cleaning. Hydroxyl radicals are potent oxidants and they were generated via the photolysis of H2O2. Oxidative damage caused by these radicals included reduced flexural strength and altered color for the acrylic resin. Nonetheless, the degraded flexural strength and altered color of acrylic resin after 500 times of cleaning in the disinfection system would be within clinically acceptable levels. PMID:23903632

  18. Effect of aging on tear strength and cytotoxicity of soft denture lining materials; in vitro

    PubMed Central

    Landayan, Jordi Izzard Andaya; Manaloto, Adrian Carlos Francisco; Shin, Sang-Wan

    2014-01-01

    PURPOSE The aim of this in vitro study was to evaluate the effect of aging on the tear strength and cytotoxicity of four soft denture lining materials. MATERIALS AND METHODS Four commonly used soft denture lining materials, (Coe-Comfort™ GC America Inc., Alsip, IL, USA; Coe-Soft™ GC America Inc., Alsip, IL, USA; Visco-gel Dentsply Caulk Milford, DE, USA; and Sofreliner Tough M Tokuyama Dental Corporation Tokyo, Japan) were selected. Sixty trouser-leg designed specimens per lining material were fabricated using a stainless steel mold for tear strength testing. The specimens were divided into non-thermocycling and 1000-, and 3000- thermocycling groups. For the cytotoxicity test, twenty-four disk shaped specimens per material were fabricated using a stainless steel mold. The specimens were soaked in normal saline solution for 24 h, 48 h and 72 h. Cytotoxicity was measured by XTT assay in L929 mouse fibroblasts. Data were analyzed by two way analysis of variance and Dunnett's test (P<.05). RESULTS Before thermocycling, Sofreliner Tough M (10.36 ± 1.00 N) had the highest tear strength value while Coe-Comfort™ (0.46 ± 0.10 N) had the lowest. After 3000 cycles, Sofreliner Tough M (9.65 ± 1.66 N) presented the highest value and Coe-Comfort™ (0.42 ± 0.08 N) the lowest. Sofreliner Tough M, in all incubation periods was the least toxic with significant differences compared to all other materials (P<.05). Coe-Comfort™, Coe-Soft™, and Sofreliner Tough M did not show any significant differences within their material group for all incubation periods. CONCLUSION This in vitro study revealed that aging can affect both the tear strength and cytotoxicity of soft denture materials depending on the composition. PMID:24843396

  19. The effect of acrylamide incorporation on the thermal and physical properties of denture resins

    PubMed Central

    Durkan, Rukiye; Bagis, Bora

    2013-01-01

    PURPOSE Polymethyl methacrylate (PMMA) is the most commonly used denture base material despite typically low in strength. The purpose of this study was to improve the physical properties of the PMMA based denture base resins (QC-20, Dentsply Ltd., Addlestone, UK; Stellon, AD International Ltd, Dentsply, Switzerland; Acron MC; GC Lab Technologies Inc., Alsip, Japan) by copolymerization mechanism. MATERIALS AND METHODS Control group specimens were prepared according to the manufacturer recommendations. In the copolymer groups; resins were prepared with 5%, 10%, 15% and 20% acrylamide (AAm) (Merck, Hohenbrunn, Germany) content according to the moleculer weight ratio, respectively. Chemical structure was characterized by a Bruker Vertex-70 Fourier transform infrared spectroscopy (FTIR) (Bruker Optics Inc., Ettlingen, Germany). Hardness was determined using an universal hardness tester (Struers Duramin, Struers A/S, Ballerup, Denmark) equipped with a Vickers diamond penetrator. The glass transition temperature (Tg) of control and copolymers were evaluated by Perkin Elmer Diamond DSC (Perkin Elmer, Massachusetts,USA). Statistical analyses were carried out using the statistical package SPSS for Windows, version 15.0 (SPSS, Chicago, IL, USA). The results were tested regarding the normality of distribution with the Shapiro Wilk test. Data were analyzed using ANOVA with post-hoc Tukey test (P<.01). RESULTS The copolymer synthesis was confirmed by FTIR spectroscopy. Glass transition temperature of the copolymer groups were higher than the control groups of the resins. The 10%, 15% and 20% copolymer groups of Stellon presented significantly higher than the control group in terms of hardness. 15% and 20% copolymer groups of Acron MC showed significantly higher hardness values when compared to the control group of the resin. Acrylamide addition did not affect the hardness of the QC-20 resin significantly. CONCLUSION Within the limitation of this study, it can be concluded that copolymerization of PMMA with AAm increased the hardness value and glass transition temperature of PMMA denture base resins. PMID:23755335

  20. Sensitivity of Candida Albicans Biofilm Cells Grown on Denture Acrylic to Antifungal Proteins and Chlorhexidine

    PubMed Central

    Pusateri, Christopher R.; Monaco, Edward A.; Edgerton, Mira

    2009-01-01

    Objectives Candida albicans cells form biofilms on polymeric surfaces of dentures and other prostheses introduced into the oral cavity. Many biofilm microorganisms exhibit resistance to antimicrobial agents; C. albicans cells may also develop resistance to naturally-occurring antifungal peptides in human saliva including histatins (Hsts) and defensins (hBDs). Therefore, we evaluated Hst 5 activity on C. albicans biofilm cells compared to planktonic cells and measured whether surface treatment of denture acrylic with Hst 5, hBD-3, or chlorhexidine gluconate could inhibit in vitro biofilm development. Methods Acrylic disks were preconditioned with 500 ?l saliva for 30 min, and inoculated with C. albicans cells (106 cells/ml) for 1 h, at 37 °C. Non-adherent cells were removed by washing and disks and were incubated in YPD growth medium for 24, 48, and 72 h at 37 °C. Candidacidal assays were performed on 48-hour-biofilms and on planktonically-grown cells using Hst 5 (15.5 ?M, 31.25 ?M, 62 ?M). Cell adhesion was compared on disks pre-coated with 0.12% chlorhexidine gluconate, 50 ?M Hst 5, or 0.6 ?M hBD-3 after 24 h, 48 h, and 72 h growth. Results No significant difference was observed in sensitivity to Hst 5 of biofilm cells compared to planktonic cells (p > 0.05). Pre-coating disks with hBD-3 did not inhibit biofilm development; however, Hst 5 significantly inhibited biofilm development at 72 h, while 0.12% chlorhexidine significantly inhibited biofilm development at all time intervals (p < 0.05). Conclusions C. albicans biofilm cells grown on denture acrylic are sensitive to killing by Hst 5. Surface coating acrylic with chlorhexidine or Hst 5 effectively inhibits biofilm growth and has potential therapeutic application. PMID:19249746

  1. Full mouth rehabilitation of a patient with mandibular implant screw retained Fp-3 prosthesis opposing maxillary acrylic removable over-denture

    PubMed Central

    Jain, Ashish R.; Nallaswamy, Deepak; Ariga, Padma; Philip, Jacob Mathew

    2013-01-01

    A hybrid denture is one that is fabricated over a metal framework and retained by screws threaded into the implant abutments. The anterior part of a mandibular hybrid denture is fixed on implants while the posterior part of the denture is extended and cantilevered from implants. This article presents the fabrication of a maxillary over-denture opposing mandibular implant retained hybrid prosthesis. A total of four implants were placed in the mandibular arch. Castable abutments were used to produce the optimal angulations. Framework was waxed, cast recovered, and the fit was refined until the framework seated passively on the master cast. The mandibular denture teeth were waxed to the hybrid framework, and a final wax try-in was performed to verify and correct maxillomandibular relations before processing. The prosthesis was inserted after verification of occlusion, retention, and stability. The rehabilitation of edentulous patients with hybrid dentures has been observed to achieve greater masticatory function and psychological satisfaction than with conventional over-dentures. Producing a passive-fitting substructure for a fixed removable screw retained hybrid prosthesis is arguably one of the most technically complex tasks in implant dentistry. The technique presented may not initially produce a perfectly passive framework, but use of disclosing media and adjusting the internal aspect of the casting can result in non-binding, fully seated prostheses. PMID:24015016

  2. The effect of accelerated ageing on the mechanical properties of soft denture lining materials.

    PubMed

    Hekimo?lu, C; Anil, N

    1999-09-01

    The purpose of this study was to determine the effect of simulated ageing on the physical properties of some soft denture liners. The hardness, tensile strength and percentage elongation values were determined before and after ageing treatment. At the end of the experimental ageing process softening was observed only in Simpa and Ufigel L materials. It was established that ageing had insignificant effect on the hardness of other materials. It can be presumed that there will not be significant time-related changes in the hardness of these materials. Molloplast B preserved its highest value after the ageing process, whilst that of Simpa decreased to become comparable with Ufigel P. PMID:10520150

  3. BIOMECHANICAL ANALYSIS OF THE STRESSES GENERATED BY DIFFERENT DISOCCLUSION PATTERNS IN AN IMPLANT-SUPPORTED MANDIBULAR COMPLETE DENTURE

    PubMed Central

    Greco, Gustavo Diniz; Jansen, Wellington Corrêa; Landre, Janis; Seraidarian, Paulo Isaías

    2009-01-01

    Objectives: This study evaluated by three-dimensional finite element analysis the tensions generated by different disocclusion patterns (canine guide and bilateral balanced occlusion) in an implant-supported mandibular complete denture. Material and Methods: A three-dimensional model of implant-supported mandibular complete denture was fabricated according to the Brånemark protocol. A 5-element 3.75 x 13-mm screw-shape dental implant system was modeled for this study. The implants were located in the intermental foramen region with 3-mm-high prosthetic components joined by a nickel-chromium framework with 12-mm bilateral cantilever covered by acrylic resin and 12 acrylic denture teeth. SolidWorks® software was used before and after processing the simulations. The mechanical properties of the components were inserted in the model and a 15 N load was established in fixed points, in each one of the simulations. Data were collected in the entire nickel-chromium framework. The results were displayed three-dimensionally as color graphic scales. Results: The canine guide generated greater tensions in the region of the first implant, while the bilateral balanced occlusion generated great tensions in the entire metallic framework. The maximum tension found in the simulation of the bilateral balanced occlusion was 3.22 fold higher than the one found in the simulation of the disocclusion in canine guide. Conclusion: The pattern of disocclusion in canine guide is the ideal for implant-supported mandibular complete denture. PMID:19936535

  4. Conventional versus implant-retained overlay dentures: a pilot study of masseter and anterior temporalis electromyography.

    PubMed

    Dakhilalian, Mansour; Rismanchian, Mansour; Fazel, Akbar; Basiri, Keyvan; Azadeh, Hamid; Mahmoodi, Maryam; Fayazi, Sara; Sadr-Eshkvari, Pooyan

    2014-08-01

    Implant-supported overlay dentures (ISODs) have been widely accepted among patients using conventional removable complete dentures (CRCDs). The present study aimed to comparatively study conventional and ISODs in terms of function and coordination of masticatory muscles using electromyograms. Included were 10 patients with ISODs (each with 2 implants in the intercanine area). The mean wave range (MWR) and frequency (MWF) of masseter and temporalis were recorded with (ISOD) and without (CRCD) ball attachments while maximum clenching on cotton rolls (cotton roll clenching), maximum intercuspal clenching (clenching), and unilateral gum chewing (chewing) using electromyography. Data were analyzed in SPAW using t-paired for matched groups and independent-sample t tests for unmatched ones. The MWF differences were not statistically significant with or without attachments (P > .05). Without attachments in place, the MWF of both masseter and temporalis muscles significantly decreased when patients clenched on cotton rolls (P = .01 and .02, respectively) and when chewing unilaterally (both P = .01). With attachments present, the right and left temporalis muscles did not show identical mean wave ranges while chewing (P = .01). Without attachments, this disharmony was seen in the left and right masseter muscles (P = .03). The MWR of masseter was higher in men while chewing with attachments (P = .02). Without attachments, the MWR of temporalis was higher in women while cotton roll clenching (P = .03) and chewing (P = .02). These findings are seemingly in favor of improved masticatory function and coordination in edentulous patients with the application of ISODs. PMID:25106005

  5. Dimensional Changes of Acrylic Resin Denture Bases: Conventional Versus Injection-Molding Technique

    PubMed Central

    Gharechahi, Jafar; Asadzadeh, Nafiseh; Shahabian, Foad; Gharechahi, Maryam

    2014-01-01

    Objective: Acrylic resin denture bases undergo dimensional changes during polymerization. Injection molding techniques are reported to reduce these changes and thereby improve physical properties of denture bases. The aim of this study was to compare dimensional changes of specimens processed by conventional and injection-molding techniques. Materials and Methods: SR-Ivocap Triplex Hot resin was used for conventional pressure-packed and SR-Ivocap High Impact was used for injection-molding techniques. After processing, all the specimens were stored in distilled water at room temperature until measured. For dimensional accuracy evaluation, measurements were recorded at 24-hour, 48-hour and 12-day intervals using a digital caliper with an accuracy of 0.01 mm. Statistical analysis was carried out by SPSS (SPSS Inc., Chicago, IL, USA) using t-test and repeated-measures ANOVA. Statistical significance was defined at P<0.05. Results: After each water storage period, the acrylic specimens produced by injection exhibited less dimensional changes compared to those produced by the conventional technique. Curing shrinkage was compensated by water sorption with an increase in water storage time decreasing dimensional changes. Conclusion: Within the limitations of this study, dimensional changes of acrylic resin specimens were influenced by the molding technique used and SR-Ivocap injection procedure exhibited higher dimensional accuracy compared to conventional molding. PMID:25584050

  6. Antimicrobial activity of monocaprin: a monoglyceride with potential use as a denture disinfectant.

    PubMed

    Thorgeirsdóttir, Thórunn Osk; Kristmundsdóttir, Thórdís; Thormar, Halldór; Axelsdóttir, Iris; Holbrook, W Peter

    2006-02-01

    Monocaprin is a 1-monoglyceride of capric acid that has antimicrobial activity against enveloped viruses, certain bacteria, and the yeast Candida albicans. Solutions containing monocaprin were formulated and tested in vitro against a number of micro-organisms, including species found in the oral cavity and common pathogenic species. The antimicrobial activity of monocaprin was tested with strains growing on a surface as well as in the planktonic phase. Micro-organisms tested were: Streptococcus mutans, Candida albicans, Lactobacillus sp., Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Two sets of dilutions were prepared for each test strain; one to be inoculated with the micro-organism growing in the planktonic phase and the other with the same strain growing on a filter paper disk. Control solutions were also prepared to find out if any of the excipients were affecting the microbicidal effect of monocaprin. Test strains growing on the filter paper surface were less sensitive to monocaprin than the same strain growing in its planktonic phase. C. albicans was the micro-organism that was most sensitive to monocaprin, but S. mutans also showed appreciable sensitivity. The indication that monocaprin may have potential as a topical agent against Candida was tested in an open study of denture disinfection in 32 patients attending a geriatric daycare centre. A significant, but short-term, reduction in counts of Candida on the fitting surface of full dentures was observed. PMID:16428178

  7. Effect of Nanosilver on Thermal and Mechanical Properties of Acrylic Base Complete Dentures

    PubMed Central

    Hamedi-Rad, Fahimeh; Ghaffari, Tahereh; Rezaii, Farzad; Ramazani, Ali

    2014-01-01

    Objective: Polymethyl methacrylate (PMMA), widely used as a prosthodontic base, has many disadvantages, including a high thermal expansion coefficient and low thermal conductivity, a low elasticity coefficient, low impact strength and low resistance to fatigue. This study aimed to make an in vitro comparison of the thermal conductivity, compressive strength, and tensile strength of the acrylic base of complete dentures with those of acrylic reinforced with nanosilver. Materials and Methods: For this study, 36 specimens were prepared. The specimens were divided into three groups of 12; which were further divided into two subgroups of control (unmodified PMMA) and test (PMMA mixed with 5 weight% nanosilver).The results were analysed by Independent t-test. Results: This study showed that the mean thermal conductivity and compressive strength of PMMA reinforced with nanosilver were significantly higher than the unmodified PMMA (P<0.05), while the tensile strength decreased significantly after the incorporation of nanosilver (P<0.05). Conclusion: Considering our results suggesting the favorable effect of silver nanoparticles on improving the thermal conductivity and compressive strength of PMMA, use of this material in the palatal area of maxillary acrylic resin dentures is recommended. PMID:25628675

  8. Mechanical Properties of Surface-Charged Poly(Methyl Methacrylate) as Denture Resins

    PubMed Central

    Park, Sang E.; Chao, Maggie; Raj, P. A.

    2009-01-01

    The aim of this study was to examine the mechanical properties of a new surface-modified denture resin for its suitability as denture base material. This experimental resin is made by copolymerization of methacrylic acid (MA) to poly(methyl methacrylate) (PMMA) to produce a negative charge. Four experimental groups consisted of Orthodontic Dental Resin (DENTSPLY Caulk) as a control and three groups of modified PMMA (mPMMA) produced at differing ratios of methacrylic acid (5 : 95, 10 : 90, and 20 : 80 MA : MMA). A 3-point flexural test using the Instron Universal Testing Machine (Instron Corp.) measured force-deflection curves and a complete stress versus strain history to calculate the transverse strength, transverse deflection, flexural strength, and modulus of elasticity. Analysis of Variance and Scheffe Post-test were performed on the data. Resins with increased methacrylic acid content exhibited lower strength values for the measured physical properties. The most significant decrease occurred as the methacrylic acid content was increased to 20% mPMMA. No significant differences at P < .05 were found in all parameters tested between the Control and 5% mPMMA. PMID:20339462

  9. Biological effects of soft denture reline materials on L929 cells in vitro

    PubMed Central

    Chaves, Carolina AL; Vergani, Carlos E; Thomas, Dominique; Young, Anne; Costa, Carlos AS; Machado, Ana L

    2014-01-01

    Soft denture reline materials have been developed to help patients when their oral mucosa is damaged or affected due to ill-fitting dentures or post-implant surgery. Although reports have indicated that these materials leach monomers and other components that do affect their biocompatibility, there is little information on what cell molecules may be implicated in these material/tissue interactions. The biocompatibility of six soft liners (Ufi Gel P, Sofreliner S, Durabase Soft, Trusoft, Softone and Coe Comfort) was evaluated using a mouse fibroblast cell line, L929. Within 2 h of material disc preparation, each of the materials was exposed by direct contact to L929 cells for periods of 24 and 48 h. The effect of this interaction was assessed by alamarBlue assay (for cell survival). The expression of integrin ?5?1 and transforming growth factor ?1 was also assessed using plate assays such as enzyme-linked immunosorbent assay. Trusoft, Softone and Coe Comfort showed significantly reduced cell survival compared with the other soft lining materials at each incubation period. Furthermore, there were significant differences with these same materials in the expression of both integrin ?5?1 and transforming growth factor ?1. Soft liner materials may affect cell viability and cellular proteins that have important roles in wound healing and the preservation of cell viability and function in the presence of environmental challenges and stresses. PMID:25383166

  10. In vitro comparison of two different materials for the repair of urethan dimethacrylate denture bases

    PubMed Central

    Cilingir, Altug; Bilhan, Hakan; Sulun, Tonguc; Bozdag, Ergun; Sunbuloglu, Emin

    2013-01-01

    PURPOSE The purpose of this in vitro study was to investigate the flexural properties of a recently introduced urethane dimethacrylate denture base material (Eclipse) after being repaired with two different materials. MATERIALS AND METHODS Two repair groups and a control group consisting of 10 specimens each were generated. The ES group was repaired with auto-polymerizing polymer. The EE group was repaired with the Eclipse. The E group was left intact as a control group. A 3-point bending test device which was set to travel at a crosshead speed of 5 mm/min was used. Specimens were loaded until fracture occurred and the mean displacement, maximum load, flexural modulus and flexural strength values and standard deviations were calculated for each group and the data were statistically analyzed. The results were assessed at a significance level of P<.05. RESULTS The mean "displacement", "maximum load before fracture", "flexural strength" and "flexural modulus" rates of Group E were statistically significant higher than those of Groups ES and EE, but no significant difference (P>.05) was found between the mean values of Group ES and EE. There was a statistically significant positive relation (P<.01) between the displacement and maximum load of Group ES (99.5%), Group EE (94.3%) and Group E (84.4%). CONCLUSION The more economic and commonly used self-curing acrylic resin can be recommended as an alternative repair material for Eclipse denture bases. PMID:24353876

  11. The Effect of Different Chemical Surface Treatments of Denture Teeth on Shear Bond Strength: A Comparative Study

    PubMed Central

    Palekar, Umesh; Awinashe, Vaibav; Mishra, Sunil Kumar; Kawadkar, Abhishek; Rahangdale, Tripti

    2014-01-01

    Background: The development of better cross linked acrylic resin teeth has solved the problems related to wearing and discoloration of acrylic teeth. The same cross linking at ridge lap region acts as a double edge sword as it weakens the bond between denture base and tooth. Aim of Study: The purpose of study was to evaluate the effect of surface treatment on the bond strength of resin teeth to denture base resin using monomethyl methacrylate monomer and dichloromethane with no surface treatment acting as control. Settings and Design:Denture base cylinder samples in wax (n=180) were made with maxillary central incisor attached at 450 (JIST 6506). These samples were randomly and equally divided into three groups of 60 each. These specimens were then flasked, dewaxed as per the standard protocol. Materials and Methods: Before acrylization, ridge lap area was treated as follows: Group A- no surface treatment act as control, Group B treated with monomethyl methacrylate monomer, Group C treated with dichloromethane. Digitally controlled acryliser was used for acrylization as per manufacturer’s instructions and shear bond strength was tested on Universal Testing Machine (Servo Hydraulic, 50kN High Strain, BISS Research). Statistical Analysis used: Result was statistically analyzed with One-way analysis of variance (ANOVA) and Post-hoc ANOVA Tukey’s HSD test at 5% level of significance. Results: The application of dichloromethane showed increased bond strength between cross linked acrylic resin teeth and heat cure denture base resin followed by monomethyl methacrylate monomer and control group. Conclusion: The application of dichloromethane on the ridge lap surface of the resin teeth before packing of the dough into the mold significantly increased the bond strength between cross linked acrylic resin teeth and heat cure denture base resin. PMID:25121057

  12. Oral health impacts among adults in Finland: competing effects of age, number of teeth, and removable dentures.

    PubMed

    Lahti, Satu; Suominen-Taipale, Liisa; Hausen, Hannu

    2008-06-01

    The aims of the present study were to evaluate the prevalence and severity of oral health impacts among adults and to analyse the effects of age, gender, level of education, number of teeth, and removable denture wearing on these impacts. Nationally representative data (n = 5,987) on Finnish adults aged 30+ yr were gathered in an interview, in a clinical examination, and by a questionnaire including the 14-item Oral Health Impact Profile. Subject age and the number of teeth were significantly associated with oral impacts (occurring fairly or very often) when the effects of gender, educational level, and removable dentures were considered. When subjects >/= 75 yr of age were used as the reference group, the odds ratios (95% confidence interval) were 0.5 (0.3-0.8) and 0.7 (0.5-0.9) for 30-34-yr-old and 34-74-yr-old subjects, respectively. The odds ratios for those with 1-9 teeth and for those who were edentate were 3.4 (2.4-4.9) and 4.0 (2.6-6.3), respectively (20+ teeth as reference). Number of teeth modified the effect of denture wearing, and age modified the effect of educational level on oral impacts. Impaired subjective oral health related to many missing teeth might be improved by wearing removable dentures. Population groups needing special attention are young people with low education and those for whom only a few missing teeth are replaced with removable dentures. PMID:18471245

  13. [Removal of fixed partial dentures without destruction, our experience with the KaVo CORONAflex crown removing instrument].

    PubMed

    Bertold, Molnár; Endre, Somogyi; Pál, Fejérdy

    2006-12-01

    Removal of fixed, cemented restorations is a great challenge for dental practitioner in the everyday activity. After all, prosthodontic textbooks cover only briefly the destructive methods of fixed restoration's removal and does not deal with other techniques. In many cases--i.e. at fracture of porcelain that can not be repaired in the mouth, or loosening of one anchor in a multi-unit bridgework--it would be necessary to remove the bridge without destruction. Only few literature data is available on this topic. From 1998 we have made an attempt with the KaVo CORONAflex instrument to remove various types of fixed restorations without destruction. The indication of removal, the material of the bridge, location of abutment teeth in the dental arch and success of the removal were documented in each cases. From the 81 fixed prostheses 61 were successfully removed without any destruction. Sixty two of the restorations were porcelain fused to metal; 19 of them were cast restorations with acrylic resin facing (single crowns or bridges). In most of the cases the removal of the fixed prostheses was successful without any damage, and consequently remaking of the restorations was not necessary. In this way the additional stresses associated with the patients' dental treatment could be avoided and also time and dental as well as laboratory fees could be spared. PMID:17444129

  14. Mathematical methods for assessing the prognostic of fixed partial dentures resulting from evaluating a group of dental patients in Romania.

    PubMed

    Chifor, Ioana; Mitrea, Alexandru I; Badea, Iulia Clara; Chifor, Radu; Badea, Mindra Eugenia; Mitrea, Paulina; Popa, Sever; Crisan, Maria; Avram, Ramona

    2014-01-01

    Based on some mathematical and statistical approaches, our study leads to some conclusions concerning the procedures related to the orodental prosthetics. Occlusal equilibration in orodental prosthetics is a major issue because besides motivating patients for a regular daily oral hygiene, it could significantly increase the longevity of FPR. More dental hygiene information should be given after prosthetic treatment and patients should be motivated to attend recalls on a regular basis for professional teeth-cleaning. Interdental cleaning aids should be explained and the patients have to be motivated to use them at least once a day and the using technique should be individualized. Regarding the application of the deformable models theory, implemented in the context of an expert type software environment, it is known that the fact that modelling by advanced methods and techniques based on the deformable surfaces theory increases the efficiency of the dentofacial prosthetics procedures is a domain of great interest in the actual medical research. PMID:25013455

  15. Patient satisfaction and chewing ability with implant-retained mandibular overdentures: A comparison with new complete dentures with or without preprosthetic surgery

    Microsoft Academic Search

    E. M Boerrigter; B Stegenga; G. M Raghoebar; G Boering

    1995-01-01

    Purpose: The objective of this study was to compare denture satisfaction and chewing ability of edentulous patients treated with dental implant-retained overdentures or with full dentures with or without previous preprosthetic surgery.Patients and Methods: This study was a controlled clinical trial. Thirty-eight men and 52 women participated in the study. The mean height of the anterior mandible was 21 mm

  16. Electrophoresis of tear proteins as a new diagnostic tool for two high risk groups for dry eye: computer users and contact lens wearers

    PubMed Central

    2011-01-01

    Rationale: Dry eye is the most prevalent condition seen by the ophthalmologist, in particular in elderly. The identification of new common risk factors (computer use and contact lens wear) extends the disease among the young people. The early diagnosis of dry eye is essential, but difficult, because the biochemical changes in tear film usually occur before any detectable signs. Due its advantages, electrophoresis of tear proteins could be an important tool for diagnosis of tear film impairment in high risk groups for dry eye. Objective: The role of tear proteins electrophoresis in early diagnosis of dry eye related to computer use and contact lens wear, as well as the biochemical changes in these high risk groups are presented. Methods: This review will summarize the actual data concerning the electrophoretic changes of tear proteins in computer users and contact lens wearers, two common high risk groups for dry eye. Discussion: Electrophoresis of tear proteins using automated system Hyrys–Hydrasys SEBIA France is an important tool for early diagnosis of tear film alterations and monitoring of therapy. The quantification of many proteins in a single analysis using a small quantity of unconcentrated reflex tears is the main advantage of this technique. Electrophoresis of tear proteins should became a prerequisite, in particular for computer users less than 3h/day, as well as at prescribing contact lenses. Abbreviations: DED– dry eye disease, EGF–epidermal growth factor, IL interleukins, MMP–metalloproteinase, ELISA– Enzyme–linked immunosorbent assay, SDS– sodium dodecyl sulfate, CVS– computer vision syndrome, CLRDE– contact lens– related dry eye PMID:22567044

  17. A simplified numerical simulation method of bending properties for glass fiber cloth reinforced denture base resin.

    PubMed

    Tanimoto, Yasuhiro; Nishiwaki, Tsuyoshi; Nishiyama, Norihiro; Nemoto, Kimiya; Maekawa, Zen-ichiro

    2002-06-01

    The purpose of this study was to propose a new numerical modeling of the glass fiber cloth reinforced denture base resin (GFRP). The proposed model is constructed with an isotropic shell, beam and orthotropic shell elements representing the outmost resin, interlaminar resin and glass fiber cloth, respectively. The proposed model was applied to the failure progress analysis under three-point bending conditions, the validity of the numerical model was checked through comparisons with experimental results. The failure progress behaviors involving the local failures, such as interlaminar delamination and resin failure, could be simulated using the numerical model for analyzing the failure progress of GFRP. It is concluded that the model was effective for the failure progress analysis of GFRP. PMID:12238780

  18. The evaluation of some flexural properties of a denture base resin reinforced with various aesthetic fibers.

    PubMed

    Do?an, Orhan Murat; Bolayir, Giray; Keskin, Selda; Do?an, Arife; Bek, Bülent

    2008-06-01

    This study was performed to determine whether some flexural properties of a denture base resin material could be improved through reinforcement with five types of aesthetic fibers at 3% concentration by weight and in 2, 4, and 6 mm length. Five specimens of similar dimensions were prepared for each of the test groups; base resin and the same resin with glass, rayon, polyester, nylon 6 and nylon 6,6 fibers in three different lengths. Flexural properties were evaluated by using a 3-point bending test. A visual examination was also made to determine mode of fracture of the specimens. The incorporation of different fibers in varying lengths had no significant effect on flexural strength of the resin. The specimens reinforced with nylon 6,6 fibers of 6 mm length showed the highest flexural strength. Young's modulus and maximum load suggests that such reinforcement makes resin resistant to fracture. PMID:18157685

  19. New form of administering chlorhexidine for treatment of denture-induced stomatitis

    PubMed Central

    Ryalat, Soukaina; Darwish, Rula; Amin, Wala

    2011-01-01

    Background: The purpose of this study was to evaluate the release of chlorhexidine as an antifungal drug from doped self-cured poly (methyl methacrylate) (PMMA) acrylic resin and the effect of the drug released on the growth of Candida albicans. Methods: Release of chlorhexidine was evaluated using liquid chromatography, and the effect of the drug on the growth of C. albicans was investigated microbiologically using a “well” technique on Saboraud culture medium inoculated with a resistant strain of C. albicans. Results: Chlorhexidine leached steadily out of the acrylic resin into distilled water at mouth temperature, and the sustained drug release continued throughout the 28-day test period. The drug released also demonstrated antifungal activity against the resistant strain of C. albicans. Conclusion: The findings of this study support the use of chlorhexidine-impregnated self-cured PMMA chair-side resin as a new dosage form for the treatment of denture-induced stomatitis. PMID:21753884

  20. Advanced biomaterials used for a new telescopic retainer for removable dentures.

    PubMed

    Weigl, P; Hahn, L; Lauer, H C

    2000-01-01

    Removable dentures supported by cast-metal telescopic crowns often exhibit an unpredictable increase or decrease in retentive force after being in clinical use for some time. The objective of the present in vitro study was to develop a new retainer for removable dentures and to evaluate its tribological properties. The new retainer is based on a tapered crown design and consists of a conical all-ceramic abutment crown and a coping made of electroplated gold. It was compared with conventional telescopic retainers made of cast metal. There were 30 specimens in groups of equal size by material used (abutment crown/coping): Group 1, gold/gold; Group 2, titanium/titanium; Group 3, ceramic/electroplated gold. Each specimen consisted of 2 conical-shaped abutment crowns (alpha =4 degrees; h = 6 mm; O(base) = 4,5 mm); their copings were rigidly connected at 25 mm intervals. Retentive forces were measured with a universal testing machine following axial loading to 5-400 N. Wear was simulated by 500-100, 000 joining and separating cycles in the presence of artificial saliva. Metallographic cross-sections were made to evaluate the specimens' fit and surfaces with an SEM. Retentive forces in Groups 1 and 2 increased with load, exhibiting nondirectional changes after induced wear. Sometimes the alloys' functional surfaces showed considerable tracks of wear. Neither load nor wear had any effect on Group 3 retentive forces (mean(force) = 5.03 N). The functional ceramic and gold surfaces showed no traces of wear and the best fit (median(gap) = 4.9 microm). Replacing cast metals by ceramics and electroplated gold results in retainers with clinically advantageous tribological effects, implying, in particular, high wear resistance. PMID:10898873

  1. Effect of chemical cleaning agents on the flexural strength of acrylic and hard denture line resins.

    PubMed

    Rodrigues, Sabrina Alessandra; Nunez Pantoja, Juliana Maria Costa; Takahashi, Jessica Mie Ferreira Koyama; Consani, Rafael Leonardo Xediek; Mesquita, Marcelo Ferraz

    2013-07-01

    This study sought to evaluate the disinfectants, Efferdent (EF) and 0.5% sodium hypochlorite (SH), and their effects on the flexural strength and modulus of elasticity of the hard denture liners, Kooliner (K) and New Truliner (NT), and a thermoacrylic resin, QC-20. Ninety specimens were made (50 mm x 10 mm x 3 mm) and divided into 9 groups (n = 10). The 3 control groups were Group 1: QC-20 without disinfection cycles, Group 2: K, and Group 3: NT. The 6 experimental groups were Group 4: QC-20 in EF, Group 5: K in EF, Group 6: NT in EF, Group 7: QC-20 in SH, Group 8: K in SH, and Group 9: NT in SH. Specimens were subjected to 360 cycles of disinfection involving 35-minute cycles of immersion in cleaning solutions. The materials' flexural strength and modulus of elasticity were determined using a universal testing machine at a 5 mm/minute speed of compression. The data were subjected to ANOVA, Tukey, Kruskal-Wallis, and Dunn tests (? = 0.05). Regardless of the disinfection method used, the NT hard denture liner showed the lowest flexural strength values (P < 0.05) and modulus of elasticity (P < 0.0001) compared to K and QC-20. However, flexural strength values increased after applying SH and EF (P < 0.05). QC-20 showed a higher modulus of elasticity (P < 0.033), which increased after EF was applied (P = 0.005). It can be concluded that the disinfection methods changed the mechanical properties of the tested materials. PMID:23823352

  2. Mechanical and thermal properties of polyamide versus reinforced PMMA denture base materials

    PubMed Central

    Bolayir, Giray; Boztug, Ali

    2013-01-01

    PURPOSE This in vitro study intended to investigate the mechanical and thermal characteristics of Valplast, and of polymethyl methacrylate denture base resin in which different esthetic fibers (E-glass, nylon 6 or nylon 6.6) were added. MATERIALS AND METHODS Five groups were formed: control (PMMA), PMMA-E glass, PMMA-nylon 6, PMMA-nylon 6.6 and Valplast resin. For the transverse strength test the specimens were prepared in accordance with ANSI/ADA specification No.12, and for the impact test ASTM D-256 standard were used. With the intent to evaluate the properties of transverse strength, the three-point bending (n=7) test instrument (Lloyd NK5, Lloyd Instruments Ltd, Fareham Hampshire, UK) was used at 5 mm/min. A Dynatup 9250 HV (Instron, UK) device was employed for the impact strength (n=7). All of the resin samples were tested by using thermo-mechanical analysis (Shimadzu TMA 50, Shimadzu, Japan). The data were analyzed by Kruskal-Wallis and Tukey tests for pairwise comparisons of the groups at the 0.05 level of significance. RESULTS In all mechanical tests, the highest values were observed in Valplast group (transverse strength: 117.22 ± 37.80 MPa, maximum deflection: 27.55 ± 1.48 mm, impact strength: 0.76 ± 0.03 kN). Upon examining the thermo-mechanical analysis data, it was seen that the E value of the control sample was 8.08 MPa, higher than that of the all other samples. CONCLUSION Although Valplast denture material has good mechanical strength, its elastic modulus is not high enough to meet the standard of PMMA materials. PMID:23755341

  3. Dietary Carbohydrates Modulate Candida albicans Biofilm Development on the Denture Surface

    PubMed Central

    Santana, Ivone Lima; Gonçalves, Letícia Machado; de Vasconcellos, Andréa Araújo; da Silva, Wander José; Cury, Jaime Aparecido; Cury, Altair Antoninha Del Bel

    2013-01-01

    The purpose of this study was to investigate whether dietary carbohydrates can modulate the development of Candida albicans biofilms on the denture material surface. Poly (methyl methacrylate) acrylic resin discs were fabricated and had their surface roughness measured. Biofilms of C. albicans ATCC 90028 were developed on saliva-coated specimens in culture medium without (control) or with carbohydrate supplementation by starch, starch+sucrose, glucose, or sucrose for 72 h. The cell count, metabolic activity, biovolume, average thickness, and roughness coefficient were evaluated at the adhesion phase (1.5 h) and after 24, 48, and 72 h. The secretion of proteinases and phospholipases, cell surface energy, and production of extra/intracellular polysaccharides were analyzed after 72 h of biofilm development. Data were analyzed by one- and two-way ANOVA followed by Tukey’s test at 5% significance level. In the early stages of colonization (adhesion and 24 h), the glucose group showed the highest cell counts and metabolic activity among the groups (p<0.05). After maturation (48 and 72 h), biofilms exposed to glucose, sucrose, or starch+sucrose showed higher cell counts and metabolic activity than the control and starch groups (p<0.001). Compared to the control group, biofilms developed on starch or starch+sucrose had more proteinase activity (p<0.001), whereas biofilms developed on glucose or sucrose had more phospholipase activity (p<0.05). Exposure to starch+sucrose increased the production of extracellular and intracellular polysaccharides (p<0.05). Biofilms developed on starch or without carbohydrate supplementation presented cells with more hydrophobic behavior compared to the other groups. Confocal images showed hyphae forms on biofilms exposed to starch or starch+sucrose. Within the conditions studied, it can be concluded that dietary carbohydrates can modulate biofilm development on the denture surface by affecting virulence factors and structural features. PMID:23737992

  4. INFLUENCE OF INCORPORATION OF FLUOROALKYL METHACRYLATES ON ROUGHNESS AND FLEXURAL STRENGTH OF A DENTURE BASE ACRYLIC RESIN

    PubMed Central

    Cunha, Tatiana Ramirez; Regis, Romulo Rocha; Bonatti, Marília Rodrigues; de Souza, Raphael Freitas

    2009-01-01

    Fluorinated denture base acrylic resins can present more stable physical properties when compared with conventional polymers. This study evaluated the incorporation of a fluoroalkyl methacrylate (FMA) mixture in a denture base material and its effect on roughness and flexural strength. A swelling behavior assessment of acrylic resin specimens (n=3, per substance) after 12 h of FMA or methyl methacrylate (MMA) immersion was conducted to determine the solvent properties. Rectangular specimens (n=30) were allocated to three groups, according to the concentration of FMA substituted into the monomer component of a heat-polymerized acrylic resin (Lucitone 550), as follows: 0% (control), 10% and 20% (v/v). Acrylic resin mixed with concentrations of 25% or more did not reach the dough stage and was not viable. The surface roughness and flexural strength of the specimens were tested. Variables were analyzed by ANOVA and Tukey's test (?=0.05). Immersion in FMA produced negligible swelling, and MMA produced obvious swelling and dissolution of the specimens. Surface roughness at concentrations of 0%, 10% and 20% were: 0.25 ± 0.04, 0.24 ± 0.04, 0.22 ± 0.03 ?m (F=1.78; p=0.189, not significant). Significant differences were found for flexural strength (F=15.92; p<0.001) and modulus of elasticity (F=7.67; p=0.002), with the following results: 96 ± 6, 82 ± 5, 84 ± 6 MPa, and 2,717 ± 79, 2,558 ± 128, 2574 ± 87 MPa, respectively. The solvent properties of FMA against acrylic resin are weak, which would explain why concentrations over 20% were not viable. Surface changes were not detected after the incorporation of FMA in the denture base acrylic resin tested. The addition of FMA into denture base resin may lower the flexural strength and modulus of elasticity, regardless of the tested concentration. PMID:19274394

  5. New phosphated poly(methyl methacrylate) polymers for the prevention of denture-induced microbial infection: an in vitro study

    PubMed Central

    Raj, Periathamby Antony; Dentino, Andrew R

    2011-01-01

    Purpose Poly(methyl methacrylate) (PMMA) has been widely used as a denture-base acrylic resin due to its excellent physical and mechanical properties. However, the material is highly prone to microbial fouling that often leads to Candida-associated denture stomatitis. Incorporation of phosphate groups into PMMA could facilitate adsorption of salivary antimicrobials and inhibit microbial adherence on the polymer surface. An in vitro study evaluated PMMA polymers containing varying amounts of phosphate group for their efficacy to inhibit Candida albicans adhesion, adsorb salivary histatin 5, and exhibit candidacidal activity. Methods Six PMMA polymers containing 0%, 5%, 15%, 10%, 20%, and 25% of phosphate group were synthesized by bead (suspension) polymerization technique using mixtures of methyl methacrylate and methallyl phosphate as monomers. The efficacy of the polymers to inhibit the adherence of C. albicans was examined by using human saliva-coated polymer beads and radio-labeled C. albicans cells, as compared with that of PMMA. The potency of the phosphated PMMA polymers to adsorb histatin 5 was determined by measuring the radioactivity of the adsorbed labeled-peptide on the polymer surface. The candidacidal activity of the histatin 5-adsorbed polymers was assessed by using the fluorescence technique. The percent release of the fluorescent probe calcein from the C. albicans membrane caused by the disruption of the cell membrane was determined. The data were analyzed statistically by one-way ANOVA followed by Scheffé’s test (? = 0.05 and n = 6). Results The presence of ?15% phosphate content in PMMA significantly reduced the saliva-mediated adhesion of C. albicans. Phosphated PMMA polymers showed significantly enhanced adsorption of histatin 5 in a phosphate density-dependent manner. The candidacidal activity of the histatin 5-bound polymers increased significantly with the increase in the phosphate content of the polymer. Conclusion Phosphated PMMA polymers have the potential to serve as novel denture-base resins, which may reduce C. albicans colonization and prevent denture stomatitis. PMID:23674911

  6. Implant-retained mandibular bar-supported overlay dentures: a finite element stress analysis of four different bar heights.

    PubMed

    Rismanchian, Mansoor; Dakhilalian, Mansour; Bajoghli, Farshad; Ghasemi, Ehsan; Sadr-Eshkevari, Pooyan

    2012-04-01

    Proper stress distribution on dental implants is necessary in bar-retained implant overlay dentures. We aimed to comparatively assess this stress distribution according to different bar heights using finite element models. A three-dimensional (3D) computer model of mandible with 2 implants (ITI, 4.1 mm diameter and 12 mm length) in canine areas and an overlying implant-supported bar-retained overlay denture were simulated with 0-, 1-, 2-, and 3-mm bar heights using ABAQUS software. A vertical force was applied to the left first molar and gradually increased from 0 to 50 N. The resultant stress distribution was evaluated. Bars of 1 and 2 mm in height transferred the least stress to the implants (3.882 and 3.896 MPa, respectively). The 0-mm height of the bar connection transferred the highest stress value (4.277 MPa). The amount of stress transferred by 3-mm heights of the bar connection was greater than that of 1- and 2-mm bar connections and smaller than that of 0-mm bar connection (4.165 kgN). This 3D finite element analysis study suggested that the use of Dolder bar attachment with 1- and 2-mm heights could be associated with appropriate stress distribution for implant-retained overlay dentures. PMID:20545552

  7. Reinforcing effects of different fibers on denture base resin based on the fiber type, concentration, and combination.

    PubMed

    Yu, Sang-Hui; Lee, Yoon; Oh, Seunghan; Cho, Hye-Won; Oda, Yutaka; Bae, Ji-Myung

    2012-01-01

    The aim of this study was to evaluate the reinforcing effects of three types of fibers at various concentrations and in different combinations on flexural properties of denture base resin. Glass (GL), polyaromatic polyamide (PA) and ultra-high molecular weight polyethylene (PE) fibers were added to heat-polymerized denture base resin with volume concentrations of 2.6%, 5.3%, and 7.9%, respectively. In addition, hybrid fiber-reinforced composite (FRC) combined with either two or three types of fibers were fabricated. The flexural strength, modulus and toughness of each group were measured with a universal testing machine at a crosshead speed of 5 mm/min. In the single fiber-reinforced composite groups, the 5.3% GL and 7.9% GL had the highest flexural strength and modulus; 5.3% PE was had the highest toughness. Hybrid FRC such as GL/PE, which showed the highest toughness and the flexural strength, was considered to be useful in preventing denture fractures clinically. PMID:23207213

  8. Changes in roughness of denture base and reline materials by chemical disinfection or microwave irradiation. Surface roughness of denture base and reline materials

    PubMed Central

    MACHADO, Ana Lucia; GIAMPAOLO, Eunice Teresinha; VERGANI, Carlos Eduardo; de SOUZA, Juliana Feltrin; JORGE, Janaina Habib

    2011-01-01

    Objective The effect of disinfection by immersion in sodium perborate solution and microwave irradiation on surface roughness of one denture base resin (Lucitone 550 -L), 3 hard chairside reline resins (Tokuyama Rebase II-TR, New Truliner-NT, Ufi Gel hard-UH) and 3 resilient reline materials (Trusoft-T; Sofreliner-S, Dentusil-D) was evaluated. Material and methods Thirty specimens of each material were made and divided into 3 groups: Control - not disinfected; P - daily disinfection by immersing in sodium perborate solution (3.8%); MW - microwave disinfection (6 min/650 W). Roughness measurements were made after polymerization (baseline) and after 1, 3 and 28 days. Roughness differences relative to the baseline readings were analyzed by Student's t-test (P=0.05). Results At baseline, Trusoft showed the highest (P<0.001) mean surface roughness (3.54 µm), and its surface roughness was significantly reduced after 28 days of disinfection by immersion in sodium perborate (P=0.013). Roughness measurements of material Trusoft were not performed after microwave disinfection due to the severe alterations on the surface. In the 3 groups evaluated, changes in roughness were significant for materials Ufi Gel hard (from 0.11 to 0.26 µm; P?0.041) and New Truliner (0.19 to 0.76 µm; P?0.019). The roughness of materials Lucitone 550 (0.37 µm), Tokuyama Rebase II (0.37 µm), Sofreliner (0.49 µm) and Dentusil (0.38 µm) remained unaffected (P>0.05). Conclusions The roughness of the hard reline materials Ufi Gel hard and New Truliner was adversely affected by microwave disinfection, immersion in water or in sodium perborate. Microwave disinfection caused severe alterations on the surface of the resilient liner Trusoft. PMID:21986658

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

    PubMed

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

    2013-12-01

    Partially edentulous patients may be rehabilitated by the placement of removable dental prostheses, implant-supported removable dental prostheses, or partial implant fixed dental prostheses. However, it is unclear the impact of each prosthesis type over the masticatory aspects, which represents the objective of this paired clinical trial. Twelve patients sequentially received and used each of these 3 prosthesis types for 2 months, after which maximum bite force was assessed by a strain sensor and food comminution index was determined with the sieving method. Masseter and temporal muscle thicknesses during rest and maximal clenching were also evaluated by ultrasonography. Each maxillary arch received a new complete denture that was used throughout the study. Data were analyzed by analysis of variance for repeated measures, followed by the Tukey test (p < .05). Maximum bite force and food comminution index increased (p < .0001) after implant-supported dental prosthesis and implant fixed dental prosthesis use, with the higher improvement found after the latter's use. Regardless of implant-retained prosthesis type, masseter muscle thickness during maximal clenching also increased (p < .05) after implant insertion. Partial implant-supported prostheses significantly improved masseter muscle thickness and mastication, and the magnitude of this effect was related to prosthesis type. PMID:24158344

  10. Effectiveness of Different Cleaning Agents against the Colonization of Candida spp and the in Vitro Detection of the Adherence of These Yeast Cells to Denture Acrylic Surfaces

    PubMed Central

    Kalkanci, Ayse; Filiz, Banu; Kustimur, Semra

    2008-01-01

    Purpose The aim of this study is to examine the effect Klorhex and Fittydent, which are used as cleaning agents on the adhesion of Candida on the surfaces of acrylic denture and palatal mucosa. In addition, ability of yeasts to adhere to acrylic strips was evaluated after applying these agents in vitro. Materials and Methods Each group of 15 patients cleaned their dentures with either Klorhex or with Fittydent. The control group cleaned their dentures with water. Results It was found that 62.2% of the patients had colonies of Candida species on their palatal mucosa which was reduced to 51.1% after using these cleaning agents. The colonization rate with Candida spp on their dentures was reduces from 82.2% to 68.8% using these cleaning agents. The mean adhesion value of the Candida strains isolated from the acrylic strips were found to be 75 cell/strip prior to applying the Klorhex and Fittydent and 37.5 cell/strip and 15 cell/strip after applying these agents, respectively. Conclusion These results showed that Klorhex and Fittydent have a certain preventive effect on the colonization rate of Candida spp on the surface of these dentures, the palatal mucosa, as well as on the acrylic strips in vitro. PMID:18729309

  11. Cost-effectiveness of silicone and alginate impressions for complete dentures

    PubMed Central

    Hulme, C.; Yu, G.; Browne, C.; O’Dwyer, J.; Craddock, H.; Brown, S.; Gray, J.; Pavitt, S.; Fernandez, C.; Godfrey, M.; Dukanovic, G.; Brunton, P.; Hyde, T.P.

    2014-01-01

    Objective The aim of this study was to assess the cost effectiveness of silicone and alginate impressions for complete dentures. Methods Cost effectiveness analyses were undertaken alongside a UK single centre, double blind, controlled, crossover clinical trial. Taking the perspective of the healthcare sector, effectiveness is measured using the EuroQol (EQ-5D-3L) which provides a single index value for health status that may be combined with time to produce quality adjusted life years (QALYs); and Oral Health Impact Profile (OHIP-EDENT). Incremental cost effectiveness ratios are presented representing the additional cost per one unit gained. Results Mean cost was higher in the silicone impression group (£388.57 vs. £363.18). Negligible between-group differences were observed in QALY gains; the silicone group had greater mean OHIP-EDENT gains. The additional cost using silicone was £3.41 per change of one point in the OHIP-EDENT. Conclusions The silicone group was more costly, driven by the cost of materials. Changes in the EQ-5D and QALY gains over time and between arms were not statistically significant. Change in OHIP-EDENT score showed greater improvement in the silicone group and the difference between arms was statistically significant. Given negligible QALY gains and low level of resource use, results must be treated with caution. It is difficult to make robust claims about the comparative cost-effectiveness. Clinical significance Silicone impressions for complete dentures improve patients’ quality of life (OHIP-EDENT score). The extra cost of silicone impressions is £30 per patient. Dentists, patients and health care funders need to consider the clinical and financial value of silicone impressions. Different patients, different dentists, different health funders will have individual perceptions and judgements. ISRCTN01528038. NIHR-RfPB grant PB-PG-0408-16300.?? 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:24995472

  12. Dynamic viscoelastic properties of processed soft denture liners: Part I--Initial properties.

    PubMed

    Wagner, W C; Kawano, F; Dootz, E R; Koran, A

    1995-05-01

    This research evaluated the dynamic viscoelastic properties of 12 laboratory-processed soft denture liners. Specimens, 1.4 x 3 x 40 mm, were prepared according to the manufacturer's instructions. Five specimens of each material were tested under applied strain frequencies of 1, 5, or 10 Hz and temperatures of 23 degrees C and 37 degrees C. The values at 37 degrees C and 1 Hz were judged most important because they closely approximate the service environment; therefore material comparisons were made for these conditions. Samples were tested with a custom-made dynamic viscoelastometer. The statistical significance of the results was tested by ANOVA and Scheffe's intervals test. Large differences in the storage modulus (elastic stiffness) were found. One acrylic resin, Verno-Soft, showed significantly higher storage moduli than the other materials. The viscous behavior of the materials was reflected by the loss modulus; here large differences were also found. Verno-Soft again exhibited much higher values than all of the other materials. Three other acrylic resins (Super Soft, Soft-Pak, and Justi Soft) also showed significantly higher loss moduli than the other materials. Significant differences were found in the damping factor between many of the materials. Most of the acrylic and vinyl resins had higher damping factors than the silicone and polyphosphazine rubbers. The values of the storage moduli, loss moduli, and the damping factor were affected by temperature and by applied strain frequency with some materials. PMID:7658398

  13. Sorption, Solubility, Bond Strength and Hardness of Denture Soft Lining Incorporated with Silver Nanoparticles

    PubMed Central

    Chladek, Grzegorz; Kasperski, Jacek; Barszczewska-Rybarek, Izabela; ?mudzki, Jaros?aw

    2013-01-01

    The colonization of denture soft lining material by oral fungi can result in infections and stomatitis of oral tissues. In this study, 0 ppm to 200 ppm of silver nanoparticles was incorporated as an antimicrobial agent into composites to reduce the microbial colonization of lining materials. The effect of silver nanoparticle incorporation into a soft lining material on the sorption, solubility, hardness (on the Shore A scale) and tensile bond strength of the composites was investigated. The data were statistically analyzed using two-way ANOVA and Newman-Keuls post hoc tests or the chi-square Pearson test at the p < 0.05 level. An increase in the nanosilver concentration resulted in a decrease in hardness, an increase in sorption and solubility, a decrease in bond strength and a change in the failure type of the samples. The best combination of bond strength, sorption, solubility and hardness with antifungal efficacy was achieved for silver nanoparticle concentrations ranging from 20 ppm to 40 ppm. These composites did not show properties worse than those of the material without silver nanoparticles and exhibited enhanced in vitro antifungal efficiency. PMID:23271371

  14. Dynamic mechanical properties of oral mucosa: Comparison with polymeric soft denture liners.

    PubMed

    Lacoste-Ferré, M-H; Demont, Ph; Dandurand, J; Dantras, E; Duran, D; Lacabanne, C

    2011-04-01

    The purpose of this work was to characterize the viscoelastic behaviour of oral mucosa and compare it with the dynamic mechanical properties of different soft liners. For this purpose, a sample of pig oral mucosa and six commercialized soft liner samples have been investigated. A comparison was also carried with the first suitable hard rubber for dental prosthetics: vulcanite. Creep recovery (CR) and dynamic mechanical analysis (DMA) have been used to determine the mechanical modulus of oral mucosa and soft liners respectively. The Poisson ratio is used to compare mucosa bulk modulus and soft liner shear modulus. The biomechanical concept of conventional complete dentures needs a good adjustment of dynamic mechanical impedance between the base and oral mucosa. The viscoelastic mechanical property of the oral mucosa as a referent biopolymer has been confirmed in vitro. The modulus value, adjusted for old patients in physiological conditions, is in the order of 3 MPa. This study underlines the plasticization effect of absorbed water on the mechanical properties of the underlying tissue. This study allows us to define some characteristics of the most adapted biomaterial according to the clinical exigency. The required biomaterial must display the following properties: compatibility and chemical resistance with biological environment perpetuated mechanical properties during physiological conditions and clinical use, good adjustment of dynamic mechanical impedance with supporting mucosa and easy sample processing. PMID:21316614

  15. Impact strength of denture base and reline acrylic resins: An in vitro study

    PubMed Central

    Bochio, Bruna C; Wady, Amanda F; Jorge, Janaina H; Canevarolo, Sebastião V; Vergani, Carlos E

    2012-01-01

    This study evaluated the impact strength of a denture base resin (Lucitone 550—L) and four reline resins (Tokuyama Rebase II—T; Ufi Gel Hard—U; New Truliner—NT, and Kooliner—K), both intact and in a reline combination (L/L, L/T, L/U, L/NT, and L/K). For each group (n = 20), half of the specimens were thermocycled before testing. Charpy tests were performed, and the impact strengths were calculated. Data were analyzed by two-way analyses of variance and Tukey’s test (p = 0.05). For the intact groups, mean impact strength values for L (1.65 and 1.50) were significantly higher than those of the reline resins (0.38–1.17). For the relined groups, the highest mean impact strength values were produced by L/T (5.76 and 5.12), L/NT (6.20 and 6.03), and L/K (5.60 and 5.31) and the lowest by L/U (0.76 and 0.78). There were no significant differences between L and L/L. Thermocycling reduced the impact strength of T (from 0.73 to 0.38) and L/L (from 1.82 to 1.56). PMID:22977461

  16. Effect of experimental Ricinus communis solution for denture cleaning on the properties of acrylic resin teeth.

    PubMed

    Pisani, Marina Xavier; Macedo, Ana Paula; Paranhos, Helena de Freitas Oliveira; Silva, Cláudia Helena Lovato da

    2012-01-01

    This study evaluated Knoop hardness, surface roughness and color alteration of artificial teeth for dentures after immersion in water, 1% sodium hypochlorite and an experimental solution of 2% Ricinus communis (RC). Thirty specimens of Vipi, Biolux and Trilux were analyzed. Tests of Knoop hardness, surface roughness and color alteration were conducted immediately after specimen preparation (T0) and after two immersion protocols for 15 days (?T(15)) and 183 days (?T(183)). Data variation (?T) were subjected to ANOVA and Tukey's test (p<0.05). At ?T(15), Vipi presented hardness increase and Biolux presented the highest variation (p=0.01). RC caused the highest increase in hardness (p=0) and the lowest increase (p=0.005) in roughness. Biolux presented the lowest color alteration (p =0). At ?T(183), Trilux underwent the highest hardness variation (p=0). Biolux presented an increase in roughness (p=0). There was no significant differences in color alteration among the artificial teeth (p=0.06) and among solutions (p=0.08) after 183 days of immersion. All solutions (distilled water, 1% sodium hypochlorite and 2% RC) caused alterations on the analyzed properties. Both immersion protocols caused alterations on the analyzed properties. PMID:22460309

  17. An in-vitro evaluation of the flexural strength of heat-polymerized poly (methyl methacrylate) denture resin reinforced with fibers.

    PubMed

    Ladha, Komal; Shah, Dipti

    2011-12-01

    Fracture strength of denture base resins is of great concern and many approaches have been made to improve the fracture resistance of acrylic resin dentures by strengthening them. Purpose of the study was to assess the effect of a Novel pre-impregnated glass fiber reinforcement system and nylon fiber reinforcement on the flexural strength of conventional heat-polymerized poly(methylmethacrylate) [PMMA] denture resin under dry and wet storage conditions. Forty specimens of standard dimensions were prepared for each of the four experimental groups; unreinforced conventional acrylic resin and the same reinforced with unidirectional Stick (S) glass fibers, woven Stick Net (SN) glass fibers and nylon fibers. Each group was further subdivided into two groups of 20 specimens each on the basis of storage conditions (dry and wet). All 160 specimens were then subjected to a 3-point bending test and flexural strength was calculated. Statistical analysis was carried out using student t test and 1-way analysis of variance (ANOVA). Stick and Stick Net glass fiber reinforcements enhanced the flexural strength of conventional heat-cured PMMA denture resin. Specimens reinforced with Stick glass fibers exhibited highest flexural strength followed by those reinforced with Stick Net glass fibers. Nylon fiber reinforcement decreased the flexural strength of acrylic resin. All the specimens in the four groups stored under wet conditions showed decrease in flexural strength in comparison to those stored in dry conditions. The reinforcement of denture base resin with pre-impregnated glass fibers may be a useful means of strengthening denture bases. Use of nylon as a reinforcement fiber is not desirable as it decreased the flexural strength of acrylic resin. PMID:23204730

  18. Peel bond strength of resilient liner modified by the addition of antimicrobial agents to denture base acrylic resin

    PubMed Central

    ALCÂNTARA, Cristiane S.; de MACÊDO, Allana F.C.; GURGEL, Bruno C.V.; JORGE, Janaina H.; NEPPELENBROEK, Karin H.; URBAN, Vanessa M.

    2012-01-01

    In order to prolong the clinical longevity of resilient denture relining materials and reduce plaque accumulation, incorporation of antimicrobial agents into these materials has been proposed. However, this addition may affect their properties. Objective This study evaluated the effect of the addition of antimicrobial agents into one soft liner (Soft Confort, Dencril) on its peel bond strength to one denture base (QC 20, Dentsply). Material and Methods Acrylic specimens (n=9) were made (75x10x3 mm) and stored in distilled water at 37ºC for 48 h. The drug powder concentrations (nystatin 500,000U - G2; nystatin 1,000,000U - G3; miconazole 125 mg - G4; miconazole 250 mg - G5; ketoconazole 100 mg - G6; ketoconazole 200 mg - G7; chlorhexidine diacetate 5% - G8; and 10% chlorhexidine diacetate - G9) were blended with the soft liner powder before the addition of the soft liner liquid. A group (G1) without any drug incorporation was used as control. Specimens (n=9) (75x10x6 mm) were plasticized according to the manufacturers' instructions and stored in distilled water at 37ºC for 24 h. Relined specimens were then submitted to a 180-degree peel test at a crosshead speed of 10 mm/min. Data (MPa) were analyzed by analysis of variance (?=0.05) and the failure modes were visually classified. Results No significant difference was found among experimental groups (p=0.148). Cohesive failure located within the resilient material was predominantly observed in all tested groups. Conclusions Peel bond strength between the denture base and the modified soft liner was not affected by the addition of antimicrobial agents. PMID:23329241

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

    PubMed Central

    2014-01-01

    Background Over the years, there has been a strong consensus in dentistry that at least two implants are required to retain a complete mandibular denture. It has been shown in several clinical trials that one single median implant can retain a mandibular overdenture sufficiently well for up to 5 years without implant failures, when delayed loading was used. However, other trials have reported conflicting results with in part considerable failure rates when immediate loading was applied. Therefore it is the purpose of the current randomized clinical trial to test the hypothesis that immediate loading of a single mandibular midline implant with an overdenture will result in a comparable clinical outcome as using the standard protocol of delayed loading. Methods/design This prospective nine-center randomized controlled clinical trial is still ongoing. The final patient will complete the trial in 2016. In total, 180 edentulous patients between 60 and 89 years with sufficient complete dentures will receive one median implant in the edentulous mandible, which will retain the existing complete denture using a ball attachment. Loading of the median implant is either immediately after implant placement (experimental group) or delayed by 3 months of submerged healing at second-stage surgery (control group). Follow-up of patients will be performed for 24 months after implant loading. The primary outcome measure is non-inferiority of implant success rate of the experimental group compared to the control group. The secondary outcome measures encompass clinical, technical and subjective variables. The study was funded by the Deutsche Forschungsgemeinschaft (German research foundation, KE 477/8-1). Discussion This multi-center clinical trial will give information on the ability of a single median implant to retain a complete mandibular denture when immediately loaded. If viable, this treatment option will strongly improve everyday dental practice. Trial registration The trial has been registered at Deutsches Register Klinischer Studien (German register of clinical trials) under DRKS-ID: DRKS00003730 since 23 August 2012. (http://www.germanctr.de). PMID:24884848

  20. Immediate loading of maxillary and mandibular implant-supported fixed complete dentures: a 1- to 10-year retrospective study.

    PubMed

    Ji, Ting-Jen; Kan, Joseph Y K; Rungcharassaeng, Kitichai; Roe, Phillip; Lozada, Jaime L

    2012-09-01

    This study evaluated the success rates of 50 full-arch maxillary and/or mandibular implant-supported fixed complete dentures. After a mean follow-up time of 42.1 months, 269 implants remained in function, which corresponded to cumulative implant success rates of 85.2% and an absolute success rate of 90.6% (269/297 implants). This study suggested that higher implant failure rates might be associated with a dental history of bruxism (29.3%) vs no history of bruxism (4.6%) and surgeons with limited experience (?5 years; 12.2%) vs surgeons with experience (2.4%). PMID:21942324

  1. The effect of denture base surface pretreatments on bond strengths of two long term resilient liners

    PubMed Central

    Parkhedkar, Rambhau

    2011-01-01

    PURPOSE Purpose of this study was to evaluate effect of two surface treatments, sandblasting and monomer treatment, on tensile bond strength between two long term resilient liners and poly (methyl methacrylate) denture base resin. MATERIALS AND METHODS Two resilient liners Super-Soft and Molloplast-B were selected.Sixty acrylic resin (Trevalon) specimens with cross sectional area of 10×10 mm were prepared and divided into two groups of 30 specimens each. Each group was surface treated (n = 10) by sandblasting (250 µ alumina particles), monomer treatment (for 180 sec) and control (no surface treatment). Resilient liners were processed between 2 poly(methyl methacrylate) surfaces, in the dimensions of 10×10×3 mm. Tensile strength was determined with Instron Universal testing machine, at a crosshead speed of 5 mm/min; and the modes of failure (adhesive, cohesive or mixed) were recorded. The data were analyzed using one-way ANOVA, followed by Tukey HSD test (? = 0.05). RESULTS Monomer pretreatment of acrylic resin produced significantly higher bond strengths when compared to sandblasting and control for both resilient liners (P < .001). Sandblasting significantly decreased the bond strength for both the liners when compared to monomer pretreatment and control (P < .001). Mean bond strength of Super-Soft lined specimens was significantly higher than Molloplast-B in various surface treatment groups (P < .05). CONCLUSION Surface pretreatment of the acrylic resin with monomer prior to resilient liner application is an effective method to increase bond strength between the base and soft liner. Sandblasting, on the contrary, is not recommended as it weakens the bond between the two. PMID:21503188

  2. Reinforcement of acrylic denture base resin by incorporation of various fibers.

    PubMed

    Chen, S Y; Liang, W M; Yen, P S

    2001-01-01

    This study was designed to evaluate improvements in the mechanical properties of acrylic resin following reinforcement with three types of fiber. Polyester fiber (PE), Kevlar fiber (KF), and glass fiber (GF) were cut into 2, 4, and 6 mm lengths and incorporated at concentrations of 1, 2, and 3% (w/w). The mixtures of resin and fiber were cured at 70 degrees C in a water bath for 13 h, then at 90 degrees C for 1 h, in 70 x 25 x 15 mm stone molds, which were enclosed by dental flasks. The cured resin blocks were cut to an appropriate size and tested for impact strength and bending strength following the methods of ASTM Specification No. 256 and ISO Specification No. 1567, respectively. Specimens used in the impact strength test were reused for the Knoop hardness test. The results showed that the impact strength tended to be enhanced with fiber length and concentration, particularly PE at 3% and 6 mm length, which was significantly stronger than other formulations. Bending strength did not change significantly with the various formulations when compared to a control without fiber. The assessment of Knoop hardness revealed a complex pattern for the various formulations. The Knoop hardness of 3%, 6 mm PE-reinforced resin was comparable to that of the other formulations except for the control without fiber, but for clinical usage this did not adversely affect the merit of acrylic denture base resin. It is concluded that, for improved strength the optimum formulation to reinforce acrylic resin is by incorporation of 3%, 6 mm length PE fibers. PMID:11241340

  3. Five-year study of implant placement in regenerated bone and rehabilitation with telescopic crown retained dentures: a case report.

    PubMed

    Zafiropoulos, Gregory-George; Hoffmann, Oliver

    2009-01-01

    Various implant-supported restorations have been used successfully for several decades to rehabilitate edentulous patients. Telescopic crowns are a common treatment modality used to connect dentures to natural teeth. Although previous findings indicate that telescopic crowns can be placed successfully on implants to support overdentures, only limited data are available on this treatment approach. Eight months after extraction of all nonsalvageable teeth and socket preservation, 11 implants were inserted into the mandible and maxillae of one patient. These implants were restored 4 months later using telescopic crown-supported dentures. Bleeding on probing (BOP), plaque index (PI), clinical attachment (PAL), and radiographic bone level were evaluated over 5 years. All implants remained in function over the 5-year evaluation period. Radiography showed stable bone levels for all implants. No changes in BOP or PI (range, 2%-4% for both parameters) were observed over this time. The PAL deteriorated by 1.5 mm during the first 3 years, with no subsequent changes. We conclude that telescopic crowns can be used successfully as attachments for overdentures supported by implants in regenerated bone. PMID:20017648

  4. [Effects of mold preheating temperatures and the time of melt casting on the structure of cast denture frameworks].

    PubMed

    Biffar, R; Balz, U

    1989-11-01

    At casting temperatures of 1330 degrees to 1530 degrees C and preheating temperatures of 900 degrees to 1100 degrees C, 28 cast denture frameworks were manufactured using the cobalt chromium alloy Biosil f (Degussa). The inner defects were detected by X-ray defectoscopy and the grain numbers of clasp, connector and basis elements determined by metallography. The best results for compact castings were observed at a temperature range of 1410 degrees to 1480 degrees C. Casting previous to the melting of the last alloy cube results in a structure of clasps and connectors with 100-200 grains/mm2 and a high amount of defects; exceeding the liquidus temperature of 1380 degrees C produces grain numbers of 20-30/mm2, while a casting temperature of 1530 degrees C results in 3-5/mm2. Overheating of the melt, also in connection with low preheating temperatures, is probably a cause for the premature loss of clasp retention and fracture of many denture frameworks. PMID:2700705

  5. A Multidisciplinary Approach to Full Mouth Rehabilitation and Solving the Dilemma of Wriggling Dentures- A Case Report

    PubMed Central

    Nidawani, Prakash; Galagali, Girish; Reddy, E Srinivas; Behera, Sidhartha S P

    2014-01-01

    A successful management of full mouth rehabilitation demands a multi-disciplinary approach for its long lasting success. The present case report is intended to give an insight into the use of multiple treatment modalities to achieve a balanced, efficient and biomechanically successful prosthodontic treatment with acceptable aesthetics. Treatment of a maxillary and mandibular bilateral distal free end edentulous arch along with upper and lower anterior teeth requires plenty of contemporary and conventional prosthodontic treatment modalities. Management of distal extension situation provides complexity of biomechanical problems due to the three dimensional movements of the distal extension denture. A distal most implant can convert a distal extension RPD from a tooth and tissue supported prosthesis to a tooth and implant supported prosthesis which provides a definite stop thus enhancing the retention and stability of the prosthesis, eliminating the problems often associated with a tooth and tissue supported distal extension RPD. How to cite the article: Nidawani P, Galagali G, Reddy ES, Behera SS. A Multidisciplinary Approach to Full Mouth Rehabilitation and Solving the Dilemma of Wriggling Dentures- A Case Report. J Int Oral Health 2014;6(2):136-40. PMID:24876716

  6. A Qualitative Analysis to Compare the Effects of Surface Machining of Conventional Denture Base Resin and Two Soft Liners: A Scanning Electron Microscopic Study

    PubMed Central

    Taruna, M.; Chittaranjan, B.; Reddy, Sushendhar M.; Reddy, Kranti Kiran E.; Kulkarni, Ganesh

    2015-01-01

    Introduction: The denture base acrylic resins require adjustments for various reasons. During this process there is an alteration in the surface characteristics of the denture base. Rough surfaces promote the bacterial adhesion and plaque accumulation; therefore it is important to know the character of the surface left by instrumentation on denture base materials. This study evaluated the surface characteristics of the machined surfaces of heat-cured acrylic denture base resin, GC supersoft and Permasoft softliners. Materials and Methods: Thirty 15×15×1.5mm acrylic resin specimens were fabricated with each of three acrylic resins: Lucitone 199 denture base resin (Group I), GC supersoft (Group II) and Permasoft (Group III) softliners. They were further divided into three sub Groups A, B and C, in which Sub Group A was control group that is smooth produced against the glass. Sub Group B was produced by machining with the tungsten carbide bur and Sub group C is machined with the stone bur. Each surface was evaluated by a Scanning electron microscope and data were analyzed by analysis of variance followed by Tukey’s HSD test. Results: Stone bur produced smoother surface (Ra 3.6681?m± 0.254) on Lucitone199 than the tungsten carbide bur (Ra 5.3881?m ± 0.3373). Carbide bur produced a smoother surface on the GC super soft (Ra 1.617097?m ± 0.191767) and Permasoft softliners (Ra 2.237419?m ± 0.354259). Whereas stone bur produced rougher surface on GC supersoft(Ra 2.6?m) and Permasoft (Ra 4.184839?m ± 0.409869) softliners. Conclusion: The present study shows each type of rotary instrument produces its own characteristic surface on each type of denture base materials and that care is needed when selecting the most appropriate instrument to adjust denture base materials. These results can have a significant clinical implication. While using Lucitone 199 stone bur can be used for chair side adjustments. Tungsten carbide bur can be used for GC supersoft and Permasoft softliners to achieve smoother surface. PMID:25738082

  7. Partial tooth gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  8. Sure success partial search

    E-print Network

    Byung-Soo Choi; Thomas A. Walker; Samuel L. Braunstein

    2006-03-15

    Partial search has been proposed recently for finding the target block containing a target element with fewer queries than the full Grover search algorithm which can locate the target precisely. Since such partial searches will likely be used as subroutines for larger algorithms their success rate is important. We propose a partial search algorithm which achieves success with unit probability.

  9. Metallurgical evaluation of heat-treated nickel-chromium base denture alloy

    NASA Astrophysics Data System (ADS)

    Al Wakeel, Essam El Saeid

    2000-10-01

    In this study, a combination of solution treatment at 1050°C for 60 min, quenching, and age hardening at 900°, 750° and 600°C for 6, 60, 600 min was carried out on as-east nickel-chromium-beryllium base denture alloy (Ticonium Premium 100 "Hard"). Changes in the microstructure following heat treatment have been investigated by light microscopy, while the composition of the microstructural constituents was determined by energy dispersive spectroscopy (EDS). The changes in the overall and dendritic Vickers hardness, which accompanied various heat treatments, were determined. X-ray diffraction, transmission electron microscopy and selected area diffraction were conducted to obtain direct crystallographic information about the phases present in the as-cast, solution-treated and aged conditions. It was shown that heat treatment has a profound effect on the microstructure of the as-cast Ticonium Premium 100 "Hard" alloy. In the as-cast condition, the alloy exhibited an inhomogeneous dendritic structure with oriented needle-like (Widmanstatten) precipitates and a discontinuous interdendritic eutectic structure. Solution treatment produced a homogenized structure as a result of dissolution of almost all the precipitates present in the as-cast condition. Aging of the solution-treated and quenched alloy, at 750°C and 600°C resulted in the precipitation of very fine precipitates in the dendritic matrix, whereas overaging was observed with aging at 900°C. There was a direct correlation between changes in the microstructure and the microhardness. The solution-treated alloy exhibited the lowest Vickers hardness value (200.5 +/- 6.5 kg/mm2), while the alloy aged at 750°C for 10 hours showed the highest value (359.1 +/- 8.1 kg/mm 2). Aging at 750° and 600°C showed a continuous increase in hardness with increasing the aging time. On the other hand the alloy aged at 900°C exhibited an increase followed by a decrease in hardness with increasing aging time. Changing the aging temperature for a given aging time caused a more pronounced effect on the microhardness than changing the aging time at a given temperature. There was no significant difference between the overall hardness and the dendritic hardness. Transmission electron microscopy and selected area diffraction in combination with x-ray diffraction studies revealed that this alloy consists of three phases in the as-cast and as-cast and aged conditions, the gamma (nickel rich) matrix phase, the NiBe eutectic phase and the gamma' (Ni3Al) precipitate phase. The strength and hardness properties of this alloy mainly depend on the precipitation of gamma' , which precipitates coherently with the gamma matrix phase.

  10. [Elucidation of cross arch stabilization for the lower unilateral free end denture in terms of vibratory science].

    PubMed

    Hojyo, S

    1989-06-01

    Cases of lower unilateral free end defect are the source of many problems in clinical dentistry. The denture design method most commonly used is cross arch stabilization which involves creating a retainer on the side opposite the defect via a bar in order to stabilize the denture and protect the retaining teeth. Almost all research on this method involves experiments using a static load. Moreover, there are few studies that attempt to clarify the relationship between the major connector and the retaining teeth. As a means of clarifying these problems, the authors used the modal analysis method and a vibrometer, both of which have proven effective in general observation of lowr denture dynamics when dynamic force is applied. This allowed them to see the relationship between the metal framework configuration and the retainer in animation and thereby study displacement quantity and damping quantity. The following interesting were obtained. 1. There were four modes detected for fixed vibration on the individual metal frameworks: 500Hz band, 1kHz band 2kHz band and 4kHz band. 2. The dynamics of the individual metal frameworks were as follows: Mode 1 was a rigid body mode in a vertical direction with a fulcrum of angle 54. Mode 2 was a horizontal rigid body mode with a fulcrum of angle 54. Mode 3 was a mixture of a horizontal rigid bode and horizontal bend mode. There was a rolling type mode observed only from the plate type. Mode 4 consisted mainly of a horizontal bend mode. This showed that there were differences among the various modes. 3. Judging from the displacement rate computed at the 500Hz band, the rate of displacement decreases as the thickness and ratio decrease. 4. Judging from linear damping quantity and damping quantity in terms of frequency, the finishing line showed a greater tendency toward resonance. 5. Analysis in terms of vibratory science using modal analysis and octave band analysis hinted at the significance of cross arch stabilization. PMID:2489641

  11. Restoration of facial symmetry in a patient with bell palsy using a modified maxillary complete denture: a case report.

    PubMed

    Bagchi, Gautam; Nath, Dilip Kumar

    2012-01-01

    Permanent facial paralysis can be devastating for a patient. Modern society's emphasis on appearance and physical beauty contributes to this problem and often leads to isolation of patients embarrassed by their appearance. Lagophthalmos with ocular exposure, loss of oral competence with resultant drooling, alar collapse with nasal airway obstruction, and difficulties with mastication and speech production are all potential consequences of facial paralysis. Affected patients are confronted with both a cosmetic defect and the functional deficits associated with loss of facial nerve function. In this case history report, a modified maxillary complete denture permitted a patient with Bell palsy to carry on daily activities with minimal facial distortion, pain, speech difficulty, and associated emotional trauma. PMID:22545260

  12. Standard of disocclusion in complete dentures supported by implants without free distal ends: analysis by the finite elements method

    PubMed Central

    GRECO, Gustavo Diniz; de LAS CASAS, Estevam Barbosa; CORNACCHIA, Tulimar P. Machado; de MAGALHÃES, Cláudia Silami; MOREIRA, Allyson Nogueira

    2012-01-01

    Objective The occlusal patterns are key requirements for the clinical success of oral rehabilitation supported by implants. This study compared the stresses generated by the disocclusion in the canine guide occlusion (CGO) and bilateral balanced occlusion (BBO) on the implants and metallic infrastructure of a complete Brånemark protocol-type denture modified with the inclusion of one posterior short implant on each side. Material and Methods A three-dimensional model simulated a mandible with seven titanium implants as pillars, five of them installed between the mental foramen and the two posterior implants, located at the midpoint of the occlusal surface of the first molar. A load of 15 N with an angle of 45º was applied to a tooth or distributed across three teeth to simulate the CGO or BBO, respectively. The commercial program ABAQUS® was used for the model development, before and after the processing of the data. The results were based on a linear static analysis and were used to compare the magnitude of the equivalent stress for each of the simulations. Results The results showed that the disocclusion in CGO generated higher stresses concentrated on the working side in the region of the short implant. In BBO, the stresses were less intense and more evenly distributed on the prosthesis. The maximum stress found in the simulation of the disocclusion in CGO was two times higher than that found in the simulation of the BBO. The point of maximum stress was located in the neck of the short implant on the working side. Conclusions Under the conditions of this study, it was concluded that the BBO pattern was more suitable than CGO for the lower complete denture supported by implants without free distal ends. PMID:22437680

  13. Partial Differential Equation Analysis in

    E-print Network

    Gilchrist, James F.

    Partial Differential Equation Analysis in Biomedical Engineering PartialDifferentialEquationAnalysisin BiomedicalEngineering Partial Differential Equation Analysis in Biomedical Engineering Case Studies of multi-variable calculus, this introduction to computer-based partial differential equation (PDE

  14. Effect of surface preparation on the bond strength of heat-polymerized denture base resin to commercially pure titanium and cobalt-chromium alloy.

    PubMed

    Kawaguchi, Tomohiro; Shimizu, Hiroshi; Lassila, Lippo V J; Vallittu, Pekka K; Takahashi, Yutaka

    2011-01-01

    The aim of this study was to investigate the bond durability of heat-polymerized denture base resin to cast CP Ti and Co-Cr alloy. The alloy specimens were divided into five groups: 1) airborne-particle abraded with 50 µm alumina (SAND), 2) Rocatec tribochemical silica coating system (RO), 3) air-abraded followed by application of Epricord Opaque Primer (EP), 4) air-abraded followed by application of Super Bond C&B liquid (SB), 5) air-abraded followed by application of Alloy Primer (AL). Heat-polymerized denture resin was applied to the bonding area and polymerized according to the manufacturer's instructions. The halves of all specimens were thermocycled up to 10,000 cycles. Before thermocycling SB and AL showed significantly higher shear bond strengths than SAND, RO, EP for both metals. The shear bond strength of AL group after thermocycling was significantly higher than that of the other groups. PMID:21383520

  15. Partial Derivative Visualization Gallery

    NSDL National Science Digital Library

    Roberts, Lila F.

    2004-11-11

    This resource is a small gallery of demos for illustrating partial derivatives geometrically. These animations can be used by instructors in a classroom setting or by students to aid in acquiring a visualization background for partial derivatives. Two file formats, gif and QuickTime files are used for the animations which can be downloaded.

  16. Influence of hormone supplementation therapy on the incidence of denture stomatitis and on chemiluminescent activity of polymorphonuclear granulocytes in blood of menopausal-aged women

    PubMed Central

    2010-01-01

    Background Menopause is a health and social problem that affects a large number of women. Inadequate quantity of steroid hormones also impacts quality of the mucous membrane of the oral cavity. During menopausal age, many women wear removable prosthetic restorations in order to replace missing teeth. Such restorations may facilitate the development of inflammations in the surface of the oral cavity, referred to as denture stomatitis. Objective The aim of the study was to evaluate the influence of hormone supplementation therapy on the incidence of Candida-associated denture stomatitis and on the metabolic activity of polymorphonuclear granulocytes in peripheral blood of female patients. Materials and methods The study was conducted on a group of women in menopausal age, users of hormone replacement therapy and of removable prosthetic restorations. Female patients were subjected to a clinical study that included interviews and physical examinations. Laboratory microbiological examinations were completed on the basis of direct swabs collected from the mucous membrane of the oral cavity and from the surface of dentures. Metabolic activity of polymorphonuclear granulocytes in peripheral blood of female patients was evaluated by means of a chemiluminescence test. Results Candida-associated denture stomatitis observed was characterized by a strong growth of fungi and a lower chemiluminescent activity of neutrophils in blood of female patients undergoing hormone supplementation therapy. Conclusions Patients using hormone supplementation therapy and removable prosthetic restorations constitute a high-risk group for Candida infections and inflammations of the mucous membrane of the oral cavity; thus they should remain under constant dental control. PMID:21147619

  17. A randomized clinical trial comparing the efficacy of mandibular implant-supported overdentures and conventional dentures in diabetic patients. Part I: Methodology and clinical outcomes

    Microsoft Academic Search

    Krishan K. Kapur; Neal R. Garrett; Michael O. Hamada; Eleni D. Roumanas; Earl Freymiller; Thomas Han; Randy M. Diener; Seymour Levin; Rodney Ida

    1998-01-01

    Statement of problem. Scientific evidence is lacking to support the general application of implant-supported mandibular overdentures.Purpose. This randomized clinical trial was undertaken to compare the efficacy of conventional mandibular and implant-supported overdentures in diabetic edentulous patients with clinically acceptable metabolic control.Method. A total of 102 diabetic patients, treated with or without insulin, were randomized to receive a new maxillary denture

  18. [Clinical and laboratory studies of bacterial adhesion to validate the choice of material for making provisional dentures for patients with periodontal diseases].

    PubMed

    Ibragimov, T I; Arutiunov, S D; Tsarev, V N; Lebedenko, I Iu; Kraveishvili, S E; Trefilov, A G; Arutiunov, D S; Lomakina, N A

    2002-01-01

    Adhesion of bacteria favoring the development of oral inflammations, including cariesogenic and periodontopathogenic (Actinobacillus actinomycetemcommitans, Streptococcus sanguis, Fusobacterium nucleatum, Staphylococcus warneri) and yeast fungi (Candida albicans), to 13 materials used for making provisional dentures was studied. Adhesion of all the studied bacteria and fungi to Russian material Esterfil Foto was the minimum. Clinical use of this material in patients with chronic generalized periodontitis showed that it was well tolerated and the treatment led to improvement of oral microbiocenosis. PMID:12056141

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

    PubMed

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

    2014-02-01

    This study evaluated the stress distribution in mandibular full-arch implant-supported fixed dentures with different veneering and metallic infrastructure materials, using three-dimensional finite element analysis. Ten models were obtained from an edentulous human mandible with a complete denture fixed by four implants. Acrylic resin (RES) and porcelain (POR) teeth were associated with infrastructures of titanium (Ti), gold (Au), silver-palladium (AgPd), chrome-cobalt (CoCr) and nickel-chrome (NiCr). A 100-N oblique was applied. The von Mises (?vM) and maximum (?max) and minimum (?min) principal stresses were obtained. The RES-AgPd group showed the lowest ?vM values, while the RES-Ni-Cr group showed the highest. In the bone tissue, the RES-Au group was the only one that showed different ?max values with a 12% increase in comparison to the other groups which had similar stress values. In the implants, the groups with Ti, Au and AgPd infrastructures, either with porcelain or resin teeth, showed ?vM values similar and lower in comparison to the groups with CoCr and NiCr infrastructures. The tooth veneering material influenced the stress values in metallic infrastructures, in which the acrylic resin had the highest values. The veneering and infrastructure materials have influence on stress values of implant-supported dentures, except for the peri-implant bone tissue. PMID:24411356

  20. Influence of dentures on SAR in the visible Chinese human head voxel phantom exposed to a mobile phone at 900 and 1800 MHz.

    PubMed

    Yu, Dong; Zhang, Ruoyu; Liu, Qian

    2012-09-01

    To investigate the influence of dentures on electromagnetic energy absorption during the daily use of a mobile phone, a high-resolution head phantom based on the Visible Chinese Human dataset was reconstructed. Simulations on phantoms with various dentures were performed by using the finite-difference time-domain method with a 0.47 wavelength dipole antenna and a mobile phone model as radiation sources at 900 and 1800 MHz. The Specific energy Absorption Rate (SAR) values including 1 and 10 g average SAR values were assessed. When the metallic dental crowns with resonance lengths of approximately one-third to one-half wavelength in the tissue nearby are parallel to the radiation source, up to 121.6% relative enhancement for 1 g average SAR and 17.1% relative enhancement for 10 g average SAR are observed due to the resonance effect in energy absorption. When the radiation sources operate in the normal configuration, the 10 g average SAR values are still in compliance with the basic restrictions established by the Institute of Electrical and Electronic Engineers (IEEE) and the International Commission on Non-Ionizing Radiation Protection (ICNIRP), indicating that the safety limits will not be challenged by the usage of dentures. PMID:22388567

  1. Partial Testing Design

    Cancer.gov

    Statistical Software Partial Testing Design (Written by Stuart G. Baker) New Approach (with ROC curves): See Baker SG, Pinsky P. A proposed design and analysis for comparing digital and analog mammography: special ROC methods for cancer screening. JASA.

  2. Partial Derivatives: Geometric Visualization

    NSDL National Science Digital Library

    James Rutledge

    This write-pair-share activity presents Calculus III students with a worksheet containing several exercises that require them to find partial derivatives of functions of two variables. Afterwards, a series of Web-based animations are used to illustrate the surface of each function, the path of the indicated partial derivative for a specified value of the variable and the value of the derivative at each point along the path.

  3. [Flow of molten metal in denture base in horizontal centrifugal casting procedure. (Part 2) Flow, inflow volume and casting time of molten metal passing through several sprues into model denture plate mold (author's transl)].

    PubMed

    Okamura, H

    1978-10-01

    Two types of spruing methods were used in the casting of the denture type model pattern (thickness, 0.43 mm). Flow of molten metal in the mold was filmed by the improved system of Part 1. When three sprues were attached to the pattern vertically, molten metal passed through each sprue gate flowed being affected by the direction of gravity and revolution of casting machine, and gathered at the lower part of the mold. Next molten metal filled the mold from the lower part to the upper part. In this spruing type, molten metal turned its direction of flow several times. At the middle stage of casting, the inflow volume per unit time (inflow rate), v (mm3/10-2)s)was evaluated as v = 12.36 + 5.16A-0.16 A2 (A: total cross-sectional areas of sprues). The inflow rate increased with increase of the area of the sprues, but it saturated. When the main sprue and the subsprues were attached at the posterior border, the molten metal filled the mold from the lower part to the upper part quietly. In this spruing type, the casting mold was set facing its sprue gates downwards. The inflow rate at the middle stage of casting was evaluated as v = 21.05 + 1.79 C (C: the cross-sectional area of the main sprue). The inflow rate increased linearly with increase of the area of the main sprue. PMID:392022

  4. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, Shabbir (Bolingbrook, IL); Kumar, Romesh (Naperville, IL); Krumpelt, Michael (Naperville, IL)

    1999-01-01

    A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

  5. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, S.; Kumar, R.; Krumpelt, M.

    1999-08-17

    A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

  6. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, Shabbir (Bolingbrook, IL); Kumar, Romesh (Naperville, IL); Krumpelt, Michael (Naperville, IL)

    2001-01-01

    A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

  7. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, S.; Kumar, R.; Krumpelt, M.

    1999-08-24

    A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

  8. Oxygen partial pressure sensor

    DOEpatents

    Dees, D.W.

    1994-09-06

    A method for detecting oxygen partial pressure and an oxygen partial pressure sensor are provided. The method for measuring oxygen partial pressure includes contacting oxygen to a solid oxide electrolyte and measuring the subsequent change in electrical conductivity of the solid oxide electrolyte. A solid oxide electrolyte is utilized that contacts both a porous electrode and a nonporous electrode. The electrical conductivity of the solid oxide electrolyte is affected when oxygen from an exhaust stream permeates through the porous electrode to establish an equilibrium of oxygen anions in the electrolyte, thereby displacing electrons throughout the electrolyte to form an electron gradient. By adapting the two electrodes to sense a voltage potential between them, the change in electrolyte conductivity due to oxygen presence can be measured. 1 fig.

  9. Oxygen partial pressure sensor

    DOEpatents

    Dees, Dennis W. (Downers Grove, IL)

    1994-01-01

    A method for detecting oxygen partial pressure and an oxygen partial pressure sensor are provided. The method for measuring oxygen partial pressure includes contacting oxygen to a solid oxide electrolyte and measuring the subsequent change in electrical conductivity of the solid oxide electrolyte. A solid oxide electrolyte is utilized that contacts both a porous electrode and a nonporous electrode. The electrical conductivity of the solid oxide electrolyte is affected when oxygen from an exhaust stream permeates through the porous electrode to establish an equilibrium of oxygen anions in the electrolyte, thereby displacing electrons throughout the electrolyte to form an electron gradient. By adapting the two electrodes to sense a voltage potential between them, the change in electrolyte conductivity due to oxygen presence can be measured.

  10. Zirconia removable telescopic dentures retained on teeth or implants for maxilla rehabilitation. Three-year observation of three cases.

    PubMed

    Zafiropoulos, Gregory-George; Rebbe, Jochen; Thielen, Ulrich; Deli, Giorgio; Beaumont, Christian; Hoffmann, Oliver

    2010-01-01

    This report addresses maxillary restoration with removable telescopic crown-retained palatal free dentures. One patient with 7 natural teeth (PERIO), a second patient with 6 dental implants (IMPL), and a third patient with 2 natural teeth and 4 dental implants (IMPL-PERIO) were treated. Zirconia copings for natural teeth and individual zirconia implant abutments were fabricated in CAD/CAM and used as primary crowns. Electroformed gold copings were used as secondary telescopes. All maxilla supraconstructions were fabricated with zirconia and CAD/CAM. Patients were monitored during a 3-year period; all teeth and implants survived, and no biological or mechanical complications occurred. The peri-implant and periodontal conditions were healthy. While recognizing the limitations of this report, results showed that fabricating removable zirconia structures by means of CAD/CAM can yield highly functional and esthetic results. Galvanoforming technology is the preferable means of fabricating secondary crowns. The combination of these techniques and materials results in a prosthetic reconstruction of high quality, good fit, and biocompatibility. Long-term studies of large populations are necessary to investigate the clinical properties of the material utilized in this type of construction. PMID:20545536

  11. The effect of esthetic fibers on impact resistance of a conventional heat-cured denture base resin.

    PubMed

    Do?an, Orhan Murat; Bolayir, Giray; Keskin, Selda; Do?an, Arife; Bek, Bülent; Boztu?, Ali

    2007-03-01

    This study was conducted to observe the changes in impact resistance of a denture base resin reinforced with five types of fiber. E-glass, polyester, rayon, nylon 6, and nylon 6/6 fibers were cut into 2, 4, and 6 mm lengths and added into the resin at a concentration of 3% by weight. Five test specimens for each formulation, as well as control specimens without fiber, were prepared using a mold including a V-shaped notch with 55 x 10 x10 mm dimensions. Impact tests were carried out using a Charpy-type tester. Additionally, surfaces of the impact sections were observed under a scanning electron microscope (SEM). Results indicated that impact energy tended to increase with fiber length, and that the highest value was recorded for rayon fiber-reinforced specimens of 6 mm length. E-glass fiber reinforcement produced relatively stable, high values for each length, whereby good interfacial strength between polymer matrix and glass fibers was confirmed by SEM analysis. PMID:17621939

  12. Comparison of Impact Strength and Fracture Morphology of Different Heat Cure Denture Acrylic Resins: An In vitro Study

    PubMed Central

    Praveen, B; Babaji, Harsha V; Prasanna, B G; Rajalbandi, Santosh Kumar; Shreeharsha, T V; Prashant, G M

    2014-01-01

    Background: The fracture of acrylic resin denture is rather common occurrence and causes inconvenience to the patients. This study was carried out to evaluate and compare the impact strength and fracture morphology of four different heat cure acrylic materials. Materials and Methods: Acrylic resin specimens were prepared using preformed metal die of dimension 65 × 10 × 3 mm. The specimens were finished, polished and subjected to impact strength evaluation using impact testing machine. The loads at which the specimens fracture are recorded and subjected to statistical analysis. Fracture surface analysis was done. Macroscopic analysis was performed by visual inspection of the fractured surfaces using a stereoscopic microscope. About 5 mm sections of all the fragments were subjected to scanning electron microscopy for microscopic analysis to verify fracture morphology. Results: Mean values of the impact strength were compared by statistical methods. The impact strength data were subjected to variance homogeneity tests. Fracture surface analysis data was analyzed by statistical methods. The mean impact strength of Lucitone 199 was higher than Acrylyn-H, DPI Heat cure & Trevalon. Conclusion: Within the limitations of this study, it was concluded that the impact strength of the acrylic resins is affected by the reinforcement of fibers. Increased intermediate fractures increased impact strength. Brittle fractures morphology showed fewer undercuts and clearer surface. Intermediate fractures morphology showed more undercuts than clear surfaces. PMID:25395786

  13. Laparoscopic partial adrenalectomy

    Microsoft Academic Search

    T. Imai; Y. Tanaka; T. Kikumori; M. Ohiwa; N. Matsuura; T. Mase; H. Funahashi

    1999-01-01

    Background: Most laparoscopic adrenalectomies involve total removal of the whole adrenal gland, and reports of laparoscopic partial adrenalectomies\\u000a have been very few. The criteria for performing a laparoscopic partial adrenalectomy have not been described.\\u000a \\u000a \\u000a \\u000a \\u000a Methods: (a) Patients with functioning adrenal tumors smaller than 3 cm in diameter were selected. (b) The solitary adrenal tumors\\u000a were evaluated by preoperative thin-slice computed

  14. Partially reflecting sheet arrays

    Microsoft Academic Search

    G. V. Trentini

    1956-01-01

    Multiple reflections of electromagnetic waves between two planes are studied, and the increase in directivity that results by placing a partially reflecting sheet in front of an antenna with a reflecting screen is investigated at a wavelength of 3.2 cm. The construction and performance of various models of such arrays is discussed. Thus, for example, a \\

  15. PARTIALLY SUPERFLUOUS OBSERVATIONS

    Microsoft Academic Search

    Hailong Qian; Yongge Tian

    2006-01-01

    Necessary and sufficient conditions are established for the second subsample to be partially redundant given the first subsample for the best linear unbiased estimator of a subset of the coefficient vector of a general linear regression model.We thank the Co-editor for his very helpful comments on an earlier draft.

  16. Partial gravity habitat study

    NASA Technical Reports Server (NTRS)

    Capps, Stephen; Lorandos, Jason; Akhidime, Eval; Bunch, Michael; Lund, Denise; Moore, Nathan; Murakawa, Kiosuke

    1989-01-01

    The purpose of this study is to investigate comprehensive design requirements associated with designing habitats for humans in a partial gravity environment, then to apply them to a lunar base design. Other potential sites for application include planetary surfaces such as Mars, variable-gravity research facilities, and a rotating spacecraft. Design requirements for partial gravity environments include locomotion changes in less than normal earth gravity; facility design issues, such as interior configuration, module diameter, and geometry; and volumetric requirements based on the previous as well as psychological issues involved in prolonged isolation. For application to a lunar base, it is necessary to study the exterior architecture and configuration to insure optimum circulation patterns while providing dual egress; radiation protection issues are addressed to provide a safe and healthy environment for the crew; and finally, the overall site is studied to locate all associated facilities in context with the habitat. Mission planning is not the purpose of this study; therefore, a Lockheed scenario is used as an outline for the lunar base application, which is then modified to meet the project needs. The goal of this report is to formulate facts on human reactions to partial gravity environments, derive design requirements based on these facts, and apply the requirements to a partial gravity situation which, for this study, was a lunar base.

  17. Morphology of partial globozoospermia.

    PubMed

    Dam, Anika H; Ramos, Liliana; Dijkman, Henry B; Woestenenk, Rob; Robben, Hannie; van den Hoven, Leonie; Kremer, Jan A

    2011-01-01

    Total globozoospermia is a rare sperm morphology disorder that consists of 100% round-headed, acrosomeless spermatozoa. There is also a larger group of patients whose sperm cells are partially acrosomeless. The aim of this investigation was to describe partial globozoospermia compared to total globozoospermia and normozoospermia. Ejaculates from 10 patients with more than 50% acrosomeless spermatozoa (partial globozoospermia), 3 patients with total globozoospermia, and 9 normozoospermic controls were analyzed with light microscopy, transmission electron microscopy, and flow cytometry. Qualitative and quantitative examination of spermatozoa from the 3 groups shows differences in the percentage of round-headed sperm cells and acrosome malformation. Total globozoospermia presents as a homogenous kind of teratozoospermia. Partial globozoospermia is a distinctive sperm malformation with an increased proportion of round-headed sperm cells and acrosome malformations compared to normozoospermia, which exists separately from total globozoospermia. It thereby contains oval sperm cells that may have distinctive malformations of the sperm head matrix, but also morphologically normal sperm cells that may be used in a clinical setting. PMID:20864651

  18. Partial Differential Equations

    Microsoft Academic Search

    Alexander B. GIVENTAL

    1907-01-01

    We classify singularities of multiple-valued solutions of higher order sys- tems of partial differential equations in the case when projections of the correspond- ing integral manifolds of the Cartan distribution in the jet space to the space of independent variables have Whitney singularities.

  19. Planning Partially for Situated Agents

    Microsoft Academic Search

    Paolo Mancarella; Fariba Sadri; Giacomo Terreni; Francesca Toni

    2004-01-01

    In recent years, within the planning literature there has been a de- parture from approaches computing total plans for given goals, in favour of ap- proaches computing partial plans. Total plans can be seen as (partially ordered) sets of actions which, if executed successfully, would lead to the achievement of the goals. Partial plans, instead, can be seen as (partially

  20. Partially coherent ultrafast spectrography

    NASA Astrophysics Data System (ADS)

    Bourassin-Bouchet, C.; Couprie, M.-E.

    2015-03-01

    Modern ultrafast metrology relies on the postulate that the pulse to be measured is fully coherent, that is, that it can be completely described by its spectrum and spectral phase. However, synthesizing fully coherent pulses is not always possible in practice, especially in the domain of emerging ultrashort X-ray sources where temporal metrology is strongly needed. Here we demonstrate how frequency-resolved optical gating (FROG), the first and one of the most widespread techniques for pulse characterization, can be adapted to measure partially coherent pulses even down to the attosecond timescale. No modification of experimental apparatuses is required; only the processing of the measurement changes. To do so, we take our inspiration from other branches of physics where partial coherence is routinely dealt with, such as quantum optics and coherent diffractive imaging. This will have important and immediate applications, such as enabling the measurement of X-ray free-electron laser pulses despite timing jitter.

  1. Partially coherent ultrafast spectrography.

    PubMed

    Bourassin-Bouchet, C; Couprie, M-E

    2015-01-01

    Modern ultrafast metrology relies on the postulate that the pulse to be measured is fully coherent, that is, that it can be completely described by its spectrum and spectral phase. However, synthesizing fully coherent pulses is not always possible in practice, especially in the domain of emerging ultrashort X-ray sources where temporal metrology is strongly needed. Here we demonstrate how frequency-resolved optical gating (FROG), the first and one of the most widespread techniques for pulse characterization, can be adapted to measure partially coherent pulses even down to the attosecond timescale. No modification of experimental apparatuses is required; only the processing of the measurement changes. To do so, we take our inspiration from other branches of physics where partial coherence is routinely dealt with, such as quantum optics and coherent diffractive imaging. This will have important and immediate applications, such as enabling the measurement of X-ray free-electron laser pulses despite timing jitter. PMID:25744080

  2. Laparoscopic partial splenic resection.

    PubMed

    Uranüs, S; Pfeifer, J; Schauer, C; Kronberger, L; Rabl, H; Ranftl, G; Hauser, H; Bahadori, K

    1995-04-01

    Twenty domestic pigs with an average weight of 30 kg were subjected to laparoscopic partial splenic resection with the aim of determining the feasibility, reliability, and safety of this procedure. Unlike the human spleen, the pig spleen is perpendicular to the body's long axis, and it is long and slender. The parenchyma was severed through the middle third, where the organ is thickest. An 18-mm trocar with a 60-mm Endopath linear cutter was used for the resection. The tissue was removed with a 33-mm trocar. The operation was successfully concluded in all animals. No capsule tears occurred as a result of applying the stapler. Optimal hemostasis was achieved on the resected edges in all animals. Although these findings cannot be extended to human surgery without reservations, we suggest that diagnostic partial resection and minor cyst resections are ideal initial indications for this minimally invasive approach. PMID:7773460

  3. Partially coherent ultrafast spectrography

    PubMed Central

    Bourassin-Bouchet, C.; Couprie, M.-E.

    2015-01-01

    Modern ultrafast metrology relies on the postulate that the pulse to be measured is fully coherent, that is, that it can be completely described by its spectrum and spectral phase. However, synthesizing fully coherent pulses is not always possible in practice, especially in the domain of emerging ultrashort X-ray sources where temporal metrology is strongly needed. Here we demonstrate how frequency-resolved optical gating (FROG), the first and one of the most widespread techniques for pulse characterization, can be adapted to measure partially coherent pulses even down to the attosecond timescale. No modification of experimental apparatuses is required; only the processing of the measurement changes. To do so, we take our inspiration from other branches of physics where partial coherence is routinely dealt with, such as quantum optics and coherent diffractive imaging. This will have important and immediate applications, such as enabling the measurement of X-ray free-electron laser pulses despite timing jitter. PMID:25744080

  4. Partial trisomy 21

    Microsoft Academic Search

    A. Hagemeijer; E. M. E. Smit

    1977-01-01

    Cytogenetic analysis of a 6-year-old girl with moderate mental retardation revealed 46 chromosomes with a tandem translocation (21;21) resulting in a partial trisomy 21. Only the terminal band 21q22 was not in triplicate. G-, Q-, R-, and C-banding techniques and silver nitrate staining of the nucleolus organizer regions (NORs) were used to identify this chromosome fully.

  5. Linear Partial Differential Equations

    NSDL National Science Digital Library

    Hancock, Matthew

    This course, presented by MIT and taught by professor Matthew Hancock, covers the partial differential equations of applied mathematics, including diffusion, Laplace/Poisson, and wave equations. Methods and tools for solving these equations are also taught. The course includes lecture notes as well as assignments and exams with solutions. MIT presents OpenCourseWare as free educational material online. No registration or enrollment is required to use the materials.

  6. Partially Reflected Diffusion

    E-print Network

    A. Singer; Z. Schuss; D. Holcman

    2007-09-02

    The radiation (reaction, Robin) boundary condition for the continuum diffusion equation is widely used in chemical and biological applications to express reactive boundaries. The underlying trajectories of the diffusing particles are believed to be partially absorbed and partially reflected at the reactive boundary, however, the relation between the reaction (radiation) constant in the Robin boundary condition and the reflection probability is still unclear. In this paper we clarify the issue by finding the relation between the reaction (radiation) constant and the absorption probability of the diffusing trajectories at the boundary. We analyze the Euler scheme for the underlying It\\^o dynamics, which is assumed to have variable drift and diffusion tensor, with partial reflection at the boundary. Trajectories that cross the boundary are terminated with a given probability and otherwise are reflected in a normal or oblique direction. We use boundary layer analysis of the corresponding Wiener path integral to resolve the non-uniform convergence of the probability density function of the numerical scheme to the solution of the Fokker-Planck equation with the Robin boundary condition, as the time step is decreased. We show that the Robin boundary condition is recovered in the limit iff trajectories are reflected in the co-normal direction. We find the relation of the reactive constant to the termination probability. We show the effect of using the new relation in numerical simulations.

  7. Treatment of molar furcation involvement using root separation and a crown and sleeve-coping telescopic denture. A longitudinal study.

    PubMed

    Hou, G L; Tsai, C C; Weisgold, A S

    1999-09-01

    Because of the inconsistent results of periodontal and prosthetic therapy, periodontists may choose to treat maxillary molar furcation involvements (FI) with poor root morphology utilizing a root resection technique (RRT). In addition, poor root morphology of the remaining root following RRT is usually considered a high risk factor for long-term periodontal and prosthetic success. The purpose of this retrospective study was to investigate the differences in the clinical periodontal parameters between molar abutments with and without molar root separation and/or resection (RSR) before and after periodontal and prosthetic therapy, using a crown and sleeve-coping telescopic denture (CSCTD). A total of 85 molars (47 maxillary and 38 mandibular) were treated in 25 subjects. There were 33 abutments without root separation/resection and 52 abutments with RSR. Forty-three CSCTD were placed, 23 in the maxillary arch and 20 in the mandibular arch. The mean observation period was 6.7+/-1.9 years (range, 5 to 13 years). The plaque index, gingival index, probing depth, clinical attachment level, and alveolar bone change were recorded. The differences in these parameters before and after periodontal and prosthetic therapy between the advanced furcation-involved molars with and without RSR were evaluated. The results revealed a remarkable improvement in the periodontal parameters in advanced Class II and Class III FI in molars with RSR as compared to those without RSR. It was, therefore, concluded that molar abutments with RSR in conjunction with a specifically designed telescopic device provide a modified approach for treating molars with advanced Class II and III FI. PMID:10505813

  8. Influence of acrylamide monomer addition to the acrylic denture-base resins on mechanical and physical properties

    PubMed Central

    Aydogan Ayaz, Elif; Durkan, Rukiye

    2013-01-01

    The aim of the study was to evaluate the effect of adding acrylamide monomer (AAm) on the characterization, flexural strength, flexural modulus and thermal degradation temperature of poly(methyl methacrylate) (PMMA) denture-base resins. Specimens (n=10) were fabricated from a conventional heat-activated QC-20 (Qc-) and a microwave heat-activated Acron MC (Ac-) PMMA resins. Powder/liquid ratio followed the manufacturer's instructions for the control groups (Qc-c and Ac-c) and for the copolymer groups, the resins were prepared with 5% (?5), 10% (?10), 15% (?15) and 20% (?20) acrylamide contents, according to the molecular weight ratio, respectively. The flexural strength and flexural modulus were measured by a three-point bending test. The data obtained were statistically analyzed by Kruskal–Wallis test (?=0.05) to determine significant differences between the groups. The chemical structures of the resins were characterized by the nuclear magnetic resonance spectroscopy. Thermal stabilities were determined by thermogravimetric analysis (TGA) with a heating rate of 10 °C?min?1 from 35 °C to 600 °C. Control groups from both acrylic resins showed the lowest flexural strength values. Qc-15 showed significant increase in the flexural strength when compared to Qc-c (P<0.01). Ac-10 and Ac-15 showed significance when compared to Ac-c (P<0.01). Acrylamide incorporation increased the elastic modulus in Qc-10, Qc-15 and Qc-20 when compared to Qc-c (P<0.01). Also significant increase was observed in Ac-10, Ac-15 and Ac-20 copolymer groups when compared to Ac-c (P<0.01). According to the 1H-nuclear magnetic resonance (NMR) results, acrylamide copolymerization was confirmed in the experimental groups. TGA results showed that the thermal stability of PMMA is increased by the insertion of AAm. PMID:24030556

  9. Influence of various metal oxides on mechanical and physical properties of heat-cured polymethyl methacrylate denture base resins

    PubMed Central

    Albayrak, Hamdi; Korkmaz, Turan; Turkyilmaz, Ilser

    2013-01-01

    PURPOSE To evaluate the effect of various metal oxides on impact strength (IS), fracture toughness (FT), water sorption (WSP) and solubility (WSL) of heat-cured acrylic resin. MATERIALS AND METHODS Fifty acrylic resin specimens were fabricated for each test and divided into five groups. Group 1 was the control group and Group 2, 3, 4 and 5 (test groups) included a mixture of 1% TiO2 and 1% ZrO2, 2% Al2O3, 2% TiO2, and 2% ZrO2 by volume, respectively. Rectangular unnotched specimens (50 mm × 6.0 mm × 4.0 mm) were fabricated and droptower impact testing machine was used to determine IS. For FT, compact test specimens were fabricated and tests were done with a universal testing machine with a cross-head speed of 5 mm/min. For WSP and WSL, discshaped specimens were fabricated and tests were performed in accordance to ISO 1567. ANOVA and Kruskal-Wallis tests were used for statistical analyses. RESULTS IS and FT values were significantly higher and WSP and WSL values were significantly lower in test groups than in control group (P<.05). Group 5 had significantly higher IS and FT values and significantly lower WSP values than other groups (P<.05) and provided 40% and 30% increase in IS and FT, respectively, compared to control group. Significantly lower WSL values were detected for Group 2 and 5 (P<.05). CONCLUSION Modification of heat-cured acrylic resin with metal oxides, especially with ZrO2, may be useful in preventing denture fractures and undesirable physical changes resulting from oral fluids clinically. PMID:24049564

  10. Effect of fiber reinforcement on impact strength of heat polymerized polymethyl methacrylate denture base resin: in vitro study and SEM analysis

    PubMed Central

    Dange, Shankar Pandurang; Thakre, Mrunali Balkrushna; Kamble, Vaibhav Deorao

    2012-01-01

    PURPOSE The aim of this in-vitro investigation was to describe the effect of reinforcement with different fibers on impact strength of heat polymerized polymethyl methacrylate (PMMA) denture base resin and to analyze the effect of surface treatment of the fibers on the impact strength. MATERIALS AND METHODS The specimens were fabricated from the dies formed as per standard ASTM D4812. 2% by weight of glass, polyethylene and polypropylene fibers were incorporated in the PMMA resin. The Izod impact testing was performed on the unnotched specimens and the values obtained were analyzed using appropriate one way ANOVA, followed by unpaired t-test. Fractured ends of the samples were subjected to the SEM analysis. RESULTS The polypropylene fibers with plasma treatment showed the highest impact strength (9.229 × 102 J/m) followed by the plasma treated polyethylene fibers (9.096 × 102 J/m), untreated polypropylene fibers (8.697 × 102 J/m), untreated polyethylene fibers (7.580 × 102 J/m), silane treated glass fibers (6.448 × 102 J/m) and untreated glass fibers (5.764 × 102 J/m). Also the surface treatment of all the fibers has shown the significant improvement in impact strength. Findings of the SEM analysis justified the improvement in impact strength after surface treatment. CONCLUSION Reinforcement with the fiber is an effective method to increase the impact strength of PMMA denture base resin. The surface treatment of fibers further increases the impact strength significantly. PMID:22439098

  11. Laparoscopic partial splenectomy

    Microsoft Academic Search

    S. Uranues; D. Grossman; L. Ludwig; R. Bergamaschi

    2007-01-01

    Background  The immunologic function of the spleen and its important role in immune defense has led to splenic-preserving surgery. This\\u000a study aimed to evaluate whether laparoscopic partial splenectomy is safe.\\u000a \\u000a \\u000a \\u000a Methods  Data on consecutive patients presenting with localized benign or malignant disease of the spleen were included in a prospective\\u000a database. The surgical technique consisted of six steps: patient positioning and trocar

  12. Publicly verifiable partial key escrow

    Microsoft Academic Search

    Wenbo Mao; Bristol BS

    1997-01-01

    . A partial key escrow cryptosystem based on publicly verifiableencryption is proposed. Partial key escrow adds a great deal ofdifficulty to mass privacy intrusion interested by malicious authorities(e.g., a human rights abusive government). Public verifiability improvesefficiency and guarantees correctness in the establishment of partiallyescrowed key.1 IntroductionThis paper proposes a publicly verifiable partial key escrow cryptosystem.In partial key escrow, a portion

  13. Free alg's via partial alg's

    E-print Network

    van Suijlekom, Walter

    Free alg's via functor on partial alg's Dion Coumans and Sam van Gool Free algebra step-by-step Free image-total functor Application to KB Free algebras via a functor on partial algebras Dion Coumans / 16 #12;Free alg's via functor on partial alg's Dion Coumans and Sam van Gool Free algebra step

  14. Partial Functions . . . Definition of a . . .

    E-print Network

    Gallier, Jean

    the bijection m 7! am 1 . Let us recall the definition of a partial function. #12;Partial Functions to an infinite computation. A partial function f: A ! B is a total function i dom(f) = A. It is customary to call

  15. Partially segmented deformable mirror

    DOEpatents

    Bliss, E.S.; Smith, J.R.; Salmon, J.T.; Monjes, J.A.

    1991-05-21

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp. 5 figures.

  16. Partially segmented deformable mirror

    DOEpatents

    Bliss, Erlan S. (Danville, CA); Smith, James R. (Livermore, CA); Salmon, J. Thaddeus (Livermore, CA); Monjes, Julio A. (San Ramon, CA)

    1991-01-01

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp.

  17. Fuchsian Partial Differential Equations

    NASA Astrophysics Data System (ADS)

    Choquet-Bruhat, Yvonne

    2008-04-01

    It is generally believed that our cosmos started with an initial singularity, the big bang. In fact all solutions of Einstein equations with compact spacelike sections present a singularity, at least in one time direction, except if the space is the flat three torus. The behavior near the singularity, chaotic or not, is a subject of active research. A case amenable to rigorous mathematical treatment is when the difference of the solution with a given spacetime metric satisfies a Fuchsian system of partial differential equations. In this article we give a more general definition than Kichenassamy and Rendall of a Fuchsian system and give a simpler proof of existence of solutions tending to zero at the singularity. Our generalization is interesting for Hamiltonian systems, as pointed out by Thibault Damour and Sophie de Buyl [10].

  18. Partial oxidation catalyst

    DOEpatents

    Krumpelt, Michael (Naperville, IL); Ahmed, Shabbir (Bolingbrook, IL); Kumar, Romesh (Naperville, IL); Doshi, Rajiv (Downers Grove, IL)

    2000-01-01

    A two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion. The dehydrogenation portion is a group VIII metal and the oxide-ion conducting portion is selected from a ceramic oxide crystallizing in the fluorite or perovskite structure. There is also disclosed a method of forming a hydrogen rich gas from a source of hydrocarbon fuel in which the hydrocarbon fuel contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion at a temperature not less than about 400.degree. C. for a time sufficient to generate the hydrogen rich gas while maintaining CO content less than about 5 volume percent. There is also disclosed a method of forming partially oxidized hydrocarbons from ethanes in which ethane gas contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion for a time and at a temperature sufficient to form an oxide.

  19. A comparative evaluation of the dimensional accuracy of heat polymerised PMMA denture base cured by different curing cycles and clamped by R S technique and conventional method – An In-vitro study

    PubMed Central

    Babu, Mandava Ramesh; Rao, C Satyanageswar; Ahmed, Syed Tauqheer; Bharat, J S V; Rao, N Venugopal; Vinod, V

    2014-01-01

    Background: The aim of this study is to evaluate the dimensional accuracy of heat polymerized PMMA denture base clamped by the conventional method and by R.S technique and cured by a different curing cycle. Materials & Methods: In this study, a total of 40 standardized maxillary record bases were fabricated with seven reference points: Point A - Incisive papilla, Point B & C - Canine region on either side, Point E & G - Midpoint of tuberosities on either side, Point F- Midpoint of the line joining the two tuberosities, Point D- Midpoint between the line joining A and F. Group A: Ten maxillary record bases were fabricated by conventional clamping method and cured by long curing cycle. Group A1: Ten maxillary record bases were fabricated by R.S tension clamping method and cured by long curing cycle. Group B: Ten maxillary record bases were fabricated by conventional clamping method and cured by short curing cycle. Group B1: Ten maxillary record bases were fabricated by R.S tension clamping method and cured by short curing cycle. The distances between the reference points i.e. A-B, A-C, A-D, D-F, B-E, C-G, E-F, F-G, B-D, D-G, CD, D-E of all three thermoplastic denture base plates were measured and recorded with the help of a travelling microscope and were used for comparison with the measured and recorded readings of processed acrylic denture bases. The data obtained was analyzed by using the One Way Analysis of Variance. Results: The overall results of the in vitro study indicate that among all the PMMA bases cured by the two clamping systems and the different curing cycle, group A` was the most dimensionally stable, followed by control group A, then followed by B` and B was most unstable. Conclusion: The study concluded that the denture bases fabricated by the R.S Technique using the long curing cycle would produce the most dimensionally stable PMMA denture bases. How to cite the article: Babu MR, Rao CS, Ahmed ST, Bharat JS, Rao NV, Vinod V. A comparative evaluation of the dimensional accuracy of heat polymerised PMMA denture base cured by different curing cycles and clamped by R S technique and conventional method – An In-vitro study. J Int Oral Health 2014;6(2):68-75. PMID:24876705

  20. Trigonometric Integrals via Partial Fractions

    ERIC Educational Resources Information Center

    Chen, H.; Fulford, M.

    2005-01-01

    Parametric differentiation is used to derive the partial fractions decompositions of certain rational functions. Those decompositions enable us to integrate some new combinations of trigonometric functions.

  1. Effect of adhesive primers on bonding strength of heat cure denture base resin to cast titanium and cobalt-chromium alloy

    PubMed Central

    Kim, Su-Sung; Yang, Hong-So; Park, Sang-Won; Lim, Hyun-Pil

    2009-01-01

    STATEMENT OF PROBLEM The poor chemical bonding of a denture base resin to cast titanium framework often introduces adhesive failure and increases microleakage. PURPOSE This study evaluated the shear bond strengths of a heat cure denture base resin to commercially pure titanium, Ti-6Al-4V alloy and a cobalt-chromium alloy using two adhesive primers. MATERIAL AND METHODS Disks of commercially pure titanium, Ti-6Al-4V alloy and a cobalt-chromium alloy were cast. Specimens without the primer were also prepared and used as the controls. The shear bond strengths were measured on a screw-driven universal testing machine. RESULTS The primers significantly (P < .05) improved the shear bond strengths of the heat cure resin to all metals. However, the specimens primed with the Alloy primer® (MDP monomer) showed higher bond strength than those primed with the MR bond® (MAC-10 monomer) on titanium. Only adhesive failure was observed at the metal-resin interface in the non-primed specimens, while the primed specimens showed mixed failure of adhesive and cohesive failure. CONCLUSIONS The use of appropriate adhesive metal primers makes it possible not only to eliminate the need for surface preparation of the metal framework before applying the heat cure resins, but also reduce the need for retentive devices on the metal substructure. In particular, the Alloy primer®, which contains the phosphoric acid monomer, MDP, might be clinically more acceptable for bonding a heat cure resin to titanium than a MR bond®, which contains the carboxylic acid monomer, MAC-10. PMID:21165254

  2. C++ Templates as Partial Evaluation

    Microsoft Academic Search

    Todd L. Veldhuizen

    1999-01-01

    This paper explores the relationship between C++ templates and partial evaluation. Templates were designed to support generic programming, but unintentionally provided the ability to perform compile-time computations and code generation. These features are completely accidental, and as a result their syntax is awkward. By recasting these features in terms of partial evaluation, a much simpler syntax can be achieved. C++

  3. Mechanism Design with Partial Revelation

    Microsoft Academic Search

    Nathanael Hyafil; Craig Boutilier

    2007-01-01

    Classic direct mechanisms require full utility revelation from agents, which can be very difficult in practical multi-attribute settings. In this work, we study par- tial revelation within the framework of one-shot mecha- nisms. Each agent's type space is partitioned into a finite set of partial types and agents (should) report the partial type within which their full type lies. A

  4. What Are Dentures?

    MedlinePLUS

    KidsHealth from Nemours for Parents for Kids for Teens Kids Home How the Body Works Puberty & Growing Up Staying Healthy Recipes & Cooking Staying Safe Health Problems Illnesses & Injuries Health Problems of Grown Ups People, Places & Things That Help ...

  5. Brief Announcement: Partial Reversal Acyclicity

    E-print Network

    Radeva, Tsvetomira

    2011-01-01

    Partial Reversal (PR) is a link reversal algorithm which ensures that an initially directed acyclic graph (DAG) is eventually a destination-oriented DAG. While proofs exist to establish the acyclicity property of PR, they ...

  6. Partial belief and expert testimony

    E-print Network

    Briggs, Rachael (Rachael Amy)

    2009-01-01

    My dissertation investigates two questions from within a partial belief framework: First, when and how should deference to experts or other information sources be qualified? Second, how closely is epistemology related to ...

  7. Efficient Inference of Partial Types

    Microsoft Academic Search

    Dexter Kozen; Jens Palsberg; Michael I. Schwartzbach

    1992-01-01

    Partial types for the ?-calculus were introduced by Thatte in 1988 (3) as a means of typing objects that are not typable with simple types,such as heterogeneous lists and persistent data. In that paper he showed that type inference for partial types was semidecidable. Decidability remained open until quite recently,when O'Keefe and Wand (2) gave an exponential time algorithm for

  8. Comparative Study to Assess the Effectiveness of Various Disinfecta- nts on two Microorganisms and the effect of same on Flexural Strength of Acrylic Denture Base Resin - An In Vitro Study

    PubMed Central

    Ganesh, S; Gujjari, Anil Kumar; S, Shylesh Kumar B; B, Ravi M; S, Sowmya; S, Meenakshi

    2013-01-01

    Background: To evaluate and compare the effectiveness of various disinfectants on Candida albicans (C.albicans) and Staphylococcus aureus (Staph.aureus) inoculated on acrylic denture base resin and effect of disinfectants on flexural strength of denture base resin. Materials & Methods: A total of 130 acrylic denture base resin specimens were fabricated and processed according to manufacturer instructions. 82 sterile specimens were used for microbiological study. 2 specimens were cultured for organism growth to ensure sterility. 40 sterile specimens each were inoculated by immersing in Sabouraud & Nutrient broth containing microorganisms for 45 minutes each. Then the specimens were immersed in chlorhexidine, glutaraldehyde & distilled water (control) for 4 & 8 minutes. Then the specimens were neutralized. After neutralization the specimens were cultured onto Sabouraud’s broth for C.albicans and Nutrient broth for Staph.aureus incubated for 72 h and observed for turbidity. At the end of 72 h subculture were made onto Sabourads dextrose agar media for C.albicans, Blood agar media for Staph.aureus and incubated for 48 h to observe growth. For flexural strength testing, 8 specimens each was immersed in the above mentioned disinfectants and distilled water for 8 & 16 minutes. Each of which was then subjected to 3 point flexural load in Lloyd’s Universal testing machine. The peak load was recorded and flexural strength values were calculated. Results: The microbiological study revealed that both disinfectants were equally effective at 4 minutes against C.albicans & Staph.aureus microorganisms. Flexural strength test revealed no significant difference between test and control groups. Conclusion: Chlorhexdine and Glutaraldehyde disinfectans are equally effective against C.albicans and Staph.aureus microorganisms. Heat polymerized acrylic denture base resin did not demonstrate any significant change in flexural strength between control and test specimens. How to cite this article: Ganesh S, Gujjari A K, Shylesh K B S, Ravi M B, Sowmya S, Meenakshi S.Comparative Study to Assess the Effectiveness of Various Disinfectants on two Microorganisms and the effect of same on Flexural Strength of Acrylic Denture Base Resin - An In Vitro Study. J Int Oral Health 2013; 5(3):55-62. PMID:24155603

  9. Well-partial orders, equivariant Grobner Bases,

    E-print Network

    California at Berkeley, University of

    Well-partial orders, equivariant Gr¨obner Bases, and applications Jan Draisma TU Eindhoven Berkeley, RTG workshop, September 2012 #12;Well-partial orders Definition on S is well-partial-order if s0, s1, s2, . . . S i Well-partial orders Definition on S is well-partial-order if s0, s

  10. Partial synchronization and partial amplitude death in mesoscale network motifs

    NASA Astrophysics Data System (ADS)

    Poel, Winnie; Zakharova, Anna; Schöll, Eckehard

    2015-02-01

    We study the interplay between network topology and complex space-time patterns and introduce a concept to analytically predict complex patterns in networks of Stuart-Landau oscillators with linear symmetric and instantaneous coupling based solely on the network topology. These patterns consist of partial amplitude death and partial synchronization and are found to exist in large variety for all undirected networks of up to 5 nodes. The underlying concept is proved to be robust with respect to frequency mismatch and can also be extended to larger networks. In addition it directly links the stability of complete in-phase synchronization to only a small subset of topological eigenvalues of a network.

  11. Partial Recovery of Quantum Entanglement

    E-print Network

    Runyao Duan; Yuan Feng; Mingsheng Ying

    2007-02-09

    Suppose Alice and Bob try to transform an entangled state shared between them into another one by local operations and classical communications. Then in general a certain amount of entanglement contained in the initial state will decrease in the process of transformation. However, an interesting phenomenon called partial entanglement recovery shows that it is possible to recover some amount of entanglement by adding another entangled state and transforming the two entangled states collectively. In this paper we are mainly concerned with the feasibility of partial entanglement recovery. The basic problem we address is whether a given state is useful in recovering entanglement lost in a specified transformation. In the case where the source and target states of the original transformation satisfy the strict majorization relation, a necessary and sufficient condition for partial entanglement recovery is obtained. For the general case we give two sufficient conditions. We also give an efficient algorithm for the feasibility of partial entanglement recovery in polynomial time. As applications, we establish some interesting connections between partial entanglement recovery and the generation of maximally entangled states, quantum catalysis, mutual catalysis, and multiple-copy entanglement transformation.

  12. Partial AUC estimation and regression.

    PubMed

    Dodd, Lori E; Pepe, Margaret S

    2003-09-01

    Accurate diagnosis of disease is a critical part of health care. New diagnostic and screening tests must be evaluated based on their abilities to discriminate diseased from nondiseased states. The partial area under the receiver operating characteristic (ROC) curve is a measure of diagnostic test accuracy. We present an interpretation of the partial area under the curve (AUC), which gives rise to a nonparametric estimator. This estimator is more robust than existing estimators, which make parametric assumptions. We show that the robustness is gained with only a moderate loss in efficiency. We describe a regression modeling framework for making inference about covariate effects on the partial AUC. Such models can refine knowledge about test accuracy. Model parameters can be estimated using binary regression methods. We use the regression framework to compare two prostate-specific antigen biomarkers and to evaluate the dependence of biomarker accuracy on the time prior to clinical diagnosis of prostate cancer. PMID:14601762

  13. Full and partial gauge fixing

    SciTech Connect

    Shirzad, A. [Institute for Studies in Theoretical Physics and Mathematics, P. O. Box 5531, Tehran 19395 (Iran, Islamic Republic of) and Department of Physics, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2007-08-15

    Gauge fixing may be done in different ways. We show that using the chain structure to describe a constrained system enables us to use either a full gauge, in which all gauged degrees of freedom are determined, or a partial gauge, in which some first class constraints remain as subsidiary conditions to be imposed on the solutions of the equations of motion. We also show that the number of constants of motion depends on the level in a constraint chain in which the gauge fixing condition is imposed. The relativistic point particle, electromagnetism, and the Polyakov string are discussed as examples and full or partial gauges are distinguished.

  14. A partially ossified falx cerebri.

    PubMed

    Zandian, A; Clarke, P; Tubbs, R S; Loukas, M

    2014-08-01

    During a routine faculty prosection of the head and neck region of an adult female cadaver, a partial ossification of the falx cerebri was found. Ossification of other dural areas or regions of the body were not found. In addition, the brain and remaining organs appeared to be grossly normal. Reports of partial ossification of the falx cerebri are still rare and while certain pathologies such as nevoid basal cell carcinoma syndrome typically present with ossification of the falx on radiographs, the causal relationship of such an abnormality remains unclear. PMID:25242251

  15. Partial pressure analysis of plasmas

    SciTech Connect

    Dylla, H.F.

    1984-11-01

    The application of partial pressure analysis for plasma diagnostic measurements is reviewed. A comparison is made between the techniques of plasma flux analysis and partial pressure analysis for mass spectrometry of plasmas. Emphasis is given to the application of quadrupole mass spectrometers (QMS). The interface problems associated with the coupling of a QMS to a plasma device are discussed including: differential-pumping requirements, electromagnetic interferences from the plasma environment, the detection of surface-active species, ion source interactions, and calibration procedures. Example measurements are presented from process monitoring of glow discharge plasmas which are useful for cleaning and conditioning vacuum vessels.

  16. Marginal fit of anterior 3-unit fixed partial zirconia restorations using different CAD/CAM systems

    PubMed Central

    Song, Tae-Jin; Kwon, Taek-Ka; Han, Jung-Suk; Lee, Jai-Bong; Kim, Sung-Hun

    2013-01-01

    PURPOSE Few studies have investigated the marginal accuracy of 3-unit zirconia fixed partial dentures (FPDs) fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM) system. The purpose of this study was to compare the marginal fit of zirconia FPDs made using two CAD/CAM systems with that of metal-ceramic FPDs. MATERIALS AND METHODS Artificial resin maxillary central and lateral incisors were prepared for 3-unit FPDs and fixed in yellow stone. This model was duplicated to epoxy resin die. On the resin die, 15 three-unit FPDs were fabricated per group (45 in total): Group A, zirconia 3-unit FPDs made with the Everest system; Group B, zirconia 3-unit FPDs made with the Lava system; and Group C, metal-ceramic 3-unit FPDs. They were cemented to resin dies with resin cement. After removal of pontic, each retainer was separated and observed under a microscope (Presize 440C). Marginal gaps of experimental groups were analyzed using one-way ANOVA and Duncan test. RESULTS Mean marginal gaps of 3-unit FPDs were 60.46 µm for the Everest group, 78.71 µm for the Lava group, and 81.32 µm for the metal-ceramic group. The Everest group demonstrated significantly smaller marginal gap than the Lava and the metal-ceramic groups (P<.05). The marginal gap did not significantly differ between the Lava and the metal-ceramic groups (P>.05). CONCLUSION The marginal gaps of anterior 3-unit zirconia FPD differed according to CAD/CAM systems, but still fell within clinically acceptable ranges compared with conventional metal-ceramic restoration. PMID:24049561

  17. Partially molten magma ocean model

    SciTech Connect

    Shirley, D.N.

    1983-02-15

    The properties of the lunar crust and upper mantle can be explained if the outer 300-400 km of the moon was initially only partially molten rather than fully molten. The top of the partially molten region contained about 20% melt and decreased to 0% at 300-400 km depth. Nuclei of anorthositic crust formed over localized bodies of magma segregated from the partial melt, then grew peripherally until they coverd the moon. Throughout most of its growth period the anorthosite crust floated on a layer of magma a few km thick. The thickness of this layer is regulated by the opposing forces of loss of material by fractional crystallization and addition of magma from the partial melt below. Concentrations of Sr, Eu, and Sm in pristine ferroan anorthosites are found to be consistent with this model, as are trends for the ferroan anorthosites and Mg-rich suites on a diagram of An in plagioclase vs. mg in mafics. Clustering of Eu, Sr, and mg values found among pristine ferroan anorthosites are predicted by this model.

  18. Gas Exchange, Partial Pressure Gradients,

    E-print Network

    Riba Sagarra, Jaume

    Gas Exchange, Partial Pressure Gradients, and the Oxygen Window Johnny E. Brian, Jr., M affect the precise gas exchange occurring in individual areas of the lungs and body tissues. To make of circulatory and gas transport physiology, and the best place to start is with normobaric physiology. LIFE

  19. Leadership in Partially Distributed Teams

    ERIC Educational Resources Information Center

    Plotnick, Linda

    2009-01-01

    Inter-organizational collaboration is becoming more common. When organizations collaborate they often do so in partially distributed teams (PDTs). A PDT is a hybrid team that has at least one collocated subteam and at least two subteams that are geographically distributed and communicate primarily through electronic media. While PDTs share many…

  20. Partial Differential Equations Paschalis Karageorgis (Pete)

    E-print Network

    Karageorgis, Paschalis

    Partial Differential Equations Paschalis Karageorgis (Pete) E-mail: pete@maths.tcd.ie Lectures listed above include the following: I. Partial differential equations by Evans, III. Applied partial differential equations by Haberman, IV. Partial differential equations, an introduction by Strauss, V. Calculus

  1. Anomalous fluctuations and partial coherency

    NASA Astrophysics Data System (ADS)

    Blažek, Mikuláš

    2001-02-01

    Partially coherent statistical distributions allow to describe the processes appearing in between the pure coherent (Poisson) and pure stochastic (Pascal or negative binomial) multiparticle production. In the past, their successful rôle in describing the data which came from different types of high energy collisions, was appreciated many times. However, the corresponding distributions usually involve average numbers of particles and thereby the information on the intermittency (considered as anomalous fluctuations in the particle density) is smeared out already at the input step. It is the purpose of the present contribution to suggest such a procedure, in frame of the quantum statistics, which takes properly into account the different number of particles produced in different bins. Taking those numbers from experimental data, the value and the trend of the parameters specifying the partial coherence can be deduced. Some first results obtained from the analysis of the data on high energy nucleus-nucleus collisions, are included, too.

  2. Supersymmetric partially interacting dark matter

    NASA Astrophysics Data System (ADS)

    Fischler, Willy; Lorshbough, Dustin; Tangarife, Walter

    2015-01-01

    We present a model of partially interacting dark matter within the framework of supersymmetry with gauge mediated symmetry breaking. Dark sector atoms are produced through Affleck-Dine baryogenesis in the dark sector while avoiding the production of Q -ball relics. We discuss the astrophysical constraints relevant for this model and the possibility of dark galactic disk formation. In addition, jet emission from rotating black holes is discussed in the context of this class of models.

  3. Tree reconstruction from partial orders

    SciTech Connect

    Kannan, S.K. (Arizona Univ., Tucson, AZ (United States)); Warnow, T.J. (Sandia National Labs., Albuquerque, NM (United States))

    1993-01-01

    The problem of constructing trees given a matrix of interleaf distances is motivated by applications in computational evolutionary biology and linguistics. The general problem is to find an edge-weighted tree which most closely approximates the distance matrix. Although the construction problem is easy when the tree exactly fits the distance matrix, optimization problems under all popular criteria are either known or conjectured to be NP-complete. In this paper we consider the related problem where we are given a partial order on the pairwise distances, and wish to construct (if possible) an edge-weighted tree realizing the partial order. In particular we are interested in partial orders which arise from experiments on triples of species, which determine either a linear ordering of the three pairwise distances (called Total Order Model or TOM experiments) or only the pair(s) of minimum distance apart (called Partial Order Model or POM experiments). The POM and TOM experimental model is inspired by the model proposed by Kannan, Lawler, and Warnow for constructing trees from experiments which determine the rooted topology for any triple of species. We examine issues of construction of trees and consistency of TOM and POM experiments, where the trees may either be weighted or unweighted. Using these experiments to construct unweighted trees without nodes of degree two is motivated by a similar problem studied by Winkler, called the Discrete Metric Realization problem, which he showed to be strongly NP-hard. We have the following results: Determining consistency of a set of TOM or POM experiments is NP-Complete whether the tree is weighted or constrained to be unweighted and without degree two nodes. We can construct unweighted trees without degree two nodes from TOM experiments in optimal O(n[sup 3]) time and from POM experiments in O(n[sup 4]) time.

  4. Tree reconstruction from partial orders

    SciTech Connect

    Kannan, S.K. [Arizona Univ., Tucson, AZ (United States); Warnow, T.J. [Sandia National Labs., Albuquerque, NM (United States)

    1993-03-01

    The problem of constructing trees given a matrix of interleaf distances is motivated by applications in computational evolutionary biology and linguistics. The general problem is to find an edge-weighted tree which most closely approximates the distance matrix. Although the construction problem is easy when the tree exactly fits the distance matrix, optimization problems under all popular criteria are either known or conjectured to be NP-complete. In this paper we consider the related problem where we are given a partial order on the pairwise distances, and wish to construct (if possible) an edge-weighted tree realizing the partial order. In particular we are interested in partial orders which arise from experiments on triples of species, which determine either a linear ordering of the three pairwise distances (called Total Order Model or TOM experiments) or only the pair(s) of minimum distance apart (called Partial Order Model or POM experiments). The POM and TOM experimental model is inspired by the model proposed by Kannan, Lawler, and Warnow for constructing trees from experiments which determine the rooted topology for any triple of species. We examine issues of construction of trees and consistency of TOM and POM experiments, where the trees may either be weighted or unweighted. Using these experiments to construct unweighted trees without nodes of degree two is motivated by a similar problem studied by Winkler, called the Discrete Metric Realization problem, which he showed to be strongly NP-hard. We have the following results: Determining consistency of a set of TOM or POM experiments is NP-Complete whether the tree is weighted or constrained to be unweighted and without degree two nodes. We can construct unweighted trees without degree two nodes from TOM experiments in optimal O(n{sup 3}) time and from POM experiments in O(n{sup 4}) time.

  5. Partial Restriction Digests Leslie Vosshall

    E-print Network

    Partial Restriction Digests 4/18/2001 Leslie Vosshall · Purpose: To generate DNA cut at a subset to the following schedule for digests [A] ­ [F]: [A] 1.0 ul Enzyme [B] 0.1 ul Enzyme [C] 0.05 ul Enzyme [D] 0.01 ul Enzyme [E] 0.005 ul Enzyme [F] 0.001 ul Enzyme [A] add 1 ul of enzyme and mix well; place digest on wet

  6. Markov processes and parabolic partial differential equations

    E-print Network

    Paris-Sud XI, Université de

    Markov processes and parabolic partial differential equations Mireille Bossy , Nicolas Champagnat stochastic differential equations (SDEs) and backward SDEs (BSDEs). The second part of this article is devoted to the links between Markov processes and parabolic partial differential equations (PDEs

  7. Partial Occlusion Drawing in Autistic Children 

    E-print Network

    Hodgson, Eleanor

    INTRODUCTION: Partial occlusion drawing in autistic individuals has received little attention in previous research. In normally developing children field independence is positively correlated with partial occlusion drawing (Morra et al., 1996...

  8. Preferential attachment with partial information

    NASA Astrophysics Data System (ADS)

    Carletti, Timoteo; Gargiulo, Floriana; Lambiotte, Renaud

    2015-01-01

    We propose a preferential attachment model for network growth where new entering nodes have a partial information about the state of the network. Our main result is that the presence of bounded information modifies the degree distribution by introducing an exponential tail, while it preserves a power law behaviour over a finite small range of degrees. On the other hand, unbounded information is sufficient to let the network grow as in the standard Barabási-Albert model. Surprisingly, the latter feature holds true also when the fraction of known nodes goes asymptotically to zero. Analytical results are compared to direct simulations.

  9. Critical Reviews in Oral Biology & Medicine: Molecular and Cellular Mechanisms That Lead to Candida Biofilm Formation

    Microsoft Academic Search

    J. M. ten Cate; F. M. Klis; T. Pereira-Cenci; W. Crielaard; P. W. J. de Groot

    2009-01-01

    Fungal infections in the oral cavity are mainly caused by C. albicans, but other Candida species are also frequently identified. They are increasing in prevalence, especially in denture-wearers and aging people, and may lead to invasive infections, which have a high mortality rate. Attachment to mucosal tissues and to abiotic surfaces and the formation of biofilms are crucial steps for

  10. PARTIALLY SPECIFIED PROBABILITIES: DECISIONS AND GAMES

    E-print Network

    Lehrer, Ehud

    a theory of decision making with a partially specified probability. The paper takes an axiomatic approach probability distribution. This paper develops a theory of decision making with a partially specified of the decision making models with a partially specified probability. The main idea is to apply the independence

  11. Partial differential equations "... partial differential equations are the basis of all physical theorems."

    E-print Network

    Frey, Pascal

    Chapter 3 Partial differential equations "... partial differential equations are the basis of all physical theorems." Bernhard Riemann (1826-1866) Partial Differential Equations (PDEs) Many natural, human at a macroscopic level by a set of partial differential equations governing averaged quantities such as density

  12. A Unified Framework for Explanation-Based Generalization of Partially Ordered and Partially Instantiated Plans

    Microsoft Academic Search

    Subbarao Kambhampati

    1994-01-01

    Abstract Most previous work in explanation based generalization (EBG) of plans dealt with totally ordered plans These methods cannot be directly applied to generalizing partially ordered partially instantiated plans, a class of plans that have received significant attention in planning In this paper we present a natural way of extending the explanation - based generalization methods to partially ordered partially

  13. Partial Return Yoke for MICE

    SciTech Connect

    Witte H.; Plate, S; ,

    2013-05-03

    The international Muon Ionization Cooling Experiment (MICE) is a large scale experiment which is presently assembled at the Rutherford Appleton Laboratory in Didcot, UK. The purpose of MICE is to demonstrate the concept of ionization cooling experimentally. Ionization cooling is an important accelerator concept which will be essential for future HEP experiments such as a potential Muon Collider or a Neutrino Factory. The MICE experiment will house up to 18 superconducting solenoids, all of which produce a substantial amount of magnetic flux. Recently it was realized that this magnetic flux leads to a considerable stray magnetic field in the MICE hall. This is a concern as technical equipment in the MICE hall may may be compromised by this. In July 2012 a concept called partial return yoke was presented to the MICE community, which reduces the stray field in the MICE hall to a safe level. This report summarizes the general concept, engineering considerations and the expected shielding performance.

  14. 20% PARTIAL SIBERIAN SNAKE IN THE AGS.

    SciTech Connect

    Huang, H; Bai, M; Brown, K A; Glenn, W; Luccio, A U; Mackay, W W; Montag, C; Ptitsyn, V; Roser, T; Tsoupas, N; Zeno, K; Ranjbar, V; Spinka, H

    2002-11-06

    An 11.4% partial Siberian snake was used to successfully accelerate polarized proton through a strong intrinsic depolarizing spin resonance in the AGS. No noticeable depolarization was observed. This opens up the possibility of using a 20% to 30% partial Siberian snake in the AGS to overcome all weak and strong depolarizing spin resonances. Some design and operation issues of the new partial Siberian snake are discussed.

  15. Quantum states with strong positive partial transpose

    SciTech Connect

    Chruscinski, Dariusz; Jurkowski, Jacek; Kossakowski, Andrzej [Institute of Physics, Nicolaus Copernicus University, Grudziadzka 5/7, 87-100 Torun (Poland)

    2008-02-15

    We construct a large class of bipartite M x N quantum states which defines a proper subset of states with positive partial transposes (PPTs). Any state from this class has PPT but the positivity of its partial transposition is recognized with respect to canonical factorization of the original density operator. We propose to call elements from this class states with strong positive partial transposes (SPPTs). We conjecture that all SPPT states are separable.

  16. Flavour from partially resolved singularities

    NASA Astrophysics Data System (ADS)

    Bonelli, G.; Bonora, L.; Ricco, A.

    2006-06-01

    In this Letter we study topological open string field theory on D-branes in a IIB background given by non-compact CY geometries O (n) ? O (- 2 - n) on P1 with a singular point at which an extra fiber sits. We wrap N D5-branes on P1 and M effective D3-branes at singular points, which are actually D5-branes wrapped on a shrinking cycle. We calculate the holomorphic Chern-Simons partition function for the above models in a deformed complex structure and find that it reduces to multi-matrix models with flavour. These are the matrix models whose resolvents have been shown to satisfy the generalized Konishi anomaly equations with flavour. In the n = 0 case, corresponding to a partial resolution of the A2 singularity, the quantum superpotential in the N = 1 unitary SYM with one adjoint and M fundamentals is obtained. The n = 1 case is also studied and shown to give rise to two-matrix models which for a particular set of couplings can be exactly solved. We explicitly show how to solve such a class of models by a quantum equation of motion technique.

  17. Partially entangled states bridge in quantum teleportation

    NASA Astrophysics Data System (ADS)

    Cai, Xiao-Fei; Yu, Xu-Tao; Shi, Li-Hui; Zhang, Zai-Chen

    2014-10-01

    The traditional method for information transfer in a quantum communication system using partially entangled state resource is quantum distillation or direct teleportation. In order to reduce the waiting time cost in hop-by-hop transmission and execute independently in each node, we propose a quantum bridging method with partially entangled states to teleport quantum states from source node to destination node. We also prove that the designed specific quantum bridging circuit is feasible for partially entangled states teleportation across multiple intermediate nodes. Compared to two traditional ways, our partially entanglement quantum bridging method uses simpler logic gates, has better security, and can be used in less quantum resource situation.

  18. Automatic Fusion of Partial Reconstructions

    NASA Astrophysics Data System (ADS)

    Wendel, A.; Hoppe, C.; Bischof, H.; Leberl, F.

    2012-07-01

    Novel image acquisition tools such as micro aerial vehicles (MAVs) in form of quad- or octo-rotor helicopters support the creation of 3D reconstructions with ground sampling distances below 1 cm. The limitation of aerial photogrammetry to nadir and oblique views in heights of several hundred meters is bypassed, allowing close-up photos of facades and ground features. However, the new acquisition modality also introduces challenges: First, flight space might be restricted in urban areas, which leads to missing views for accurate 3D reconstruction and causes fracturing of large models. This could also happen due to vegetation or simply a change of illumination during image acquisition. Second, accurate geo-referencing of reconstructions is difficult because of shadowed GPS signals in urban areas, so alignment based on GPS information is often not possible. In this paper, we address the automatic fusion of such partial reconstructions. Our approach is largely based on the work of (Wendel et al., 2011a), but does not require an overhead digital surface model for fusion. Instead, we exploit that patch-based semi-dense reconstruction of the fractured model typically results in several point clouds covering overlapping areas, even if sparse feature correspondences cannot be established. We approximate orthographic depth maps for the individual parts and iteratively align them in a global coordinate system. As a result, we are able to generate point clouds which are visually more appealing and serve as an ideal basis for further processing. Mismatches between parts of the fused models depend only on the individual point density, which allows us to achieve a fusion accuracy in the range of ±1 cm on our evaluation dataset.

  19. The partial metrics system: modeling the stepwise refinement process using partial metrics

    Microsoft Academic Search

    Robert G. Reynolds

    1987-01-01

    The Partial Metrics System design is explained, with an emphasis on the refinement process. A model, with its three phases, shows that the pseudocode refinement process can be monitored in partial metric terms.

  20. Dynamic Programming for Partially Observable Stochastic Games

    Microsoft Academic Search

    Eric A. Hansen; Daniel S. Bernstein; Shlomo Zilberstein

    2004-01-01

    We develop an exact dynamic programming algorithm for partially observable stochastic games (POSGs). The algo- rithm is a synthesis of dynamic programming for partially ob- servable Markov decision processes (POMDPs) and iterated elimination of dominated strategies in normal form games. We prove that when applied to finite-horizon POSGs, the al- gorithm iteratively eliminates very weakly dominated strate- gies without first