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Clinical and histopathological analysis of intramucosal zirconia inserts used for improving maxillary denture retention

GONÇALVES, Fábio; DIAS, Eliane Pedra; CESTARY, Tania Mari; TAGA, Rumio; ZANETTI, Raquel Virgínia; ZANETTI, Artemio; GRANJEIRO, José Mauro
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.78%
Intramucosal inserts made of zirconia ceramic have been used for the rehabilitation of edentulous patients. This study aimed to follow up on patients with complete dentures having intramucosal zirconia inserts and to perform a histological analysis of biopsies of the epithelium surrounding the inserts. Twelve 31-66-year-old subjects of both genders received complete denture treatment having the intramucosal inserts in place. Detailed clinical, prosthetic and surgical procedures were described. Clinical exams were done on postoperative days 3, 7, 15, 120 and 360. One year after denture placement, the subjects received local anesthesia and the tissues surrounding the insertion sites in the alveolar ridge were removed using a scalpel blade. Biopsies were fixed for up to 48 h in 10% phosphate-buffered formaldehyde and 5-µm-thick sections were cut and stained with hematoxylin and eosin and Gomori Trichrome. Immunohistochemistry was used to identify endothelium (anti-CD3) and T lymphocytes (anti-CD31). Removing and reinserting the denture was painful until day 15, but all patients reported a marked increase in the retention and stability of the complete denture with little or no discomfort after 30 days. The histopathological analysis showed that zirconia inserts were well tolerated by the oral mucosa...

Effect of simulated masticatory loading on the retention of stud attachments for implant overdentures

NADER, S. Abi; SOUZA, R. F. de; FORTIN, D.; KONINCK, L. De; FROMENTIN, O.; ALBUQUERQUE JUNIOR, R. F.
Fonte: WILEY-BLACKWELL PUBLISHING, INC Publicador: WILEY-BLACKWELL PUBLISHING, INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.61%
P>This study assessed the effect of simulated mastication on the retention of two stud attachment systems for 2-implants overdentures. Sixteen specimens, each simulating an edentulous ridge with implants and an overdenture were divided into two groups, according to the attachment system: Group I (Nobel Biocare ball-socket attachments) and Group II (Locator attachments). Retention forces were measured before and after 400 000 simulated masticatory loads in a customised device. Data were compared by two-way anova followed by Bonferroni test (alpha = 0 center dot 05). Group I presented significantly lower retention forces (Newtons) than Group II at baseline (10 center dot 6 +/- 3 center dot 6 and 66 center dot 4 +/- 16 center dot 0, respectively). However, differences were not significant after 400 000 loads (7 center dot 9 +/- 4 center dot 3 and 21 center dot 6 +/- 17 center dot 0). The number of cycles did not influence the measurements in Group I, whereas a non-linear descending curve was found for Group II. It was concluded that simulated mastication resulted in minor changes for the ball attachment tested. Nevertheless, it reduced the retention of Locator attachments to 40% of the baseline values, what suggests that mastication is a major factor associated with maintenance needs for this system.

"Avaliação da retenção de prótese total bimaxilar em função das características da área basal" ; Evaluation of the retention of bimaxillay complete denture in function of the characteristics of the basal area.

Cunha, Eudes Francisco da Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/01/2005 PT
Relevância na Pesquisa
46.91%
Nesta pesquisa, em 14 pacientes da Clínica de Prótese Total da Faculdade de Odontologia da Universidade de São Paulo, foi realizada a avaliação da retenção de prótese total bimaxilar em função das características da área basal por três avaliadores clínicos experientes e calibrados. Foram avaliadas as retenções vertical anterior, laterais direita e esquerda e póstero-anterior e as características da área basal: forma, tamanho, altura e tipo do rebordo e a consistência da fibromucosa. Por se tratarem de opiniões, os dados foram transformados em escores e submetidos à análise de variância não paramétrica com o teste KRUSKAL-WALLIS e paramétrica com o teste ANOVA. Concluiu-se que, na maxila, a retenção das próteses totais novas foi influenciada positivamente pelo tipo rebordo paralelo e pela consistência resiliente da fibromucosa, enquanto na mandíbula influenciaram o tamanho médio e a forma oval. As opiniões sobre a retenção e o grau de satisfação entre os avaliadores e os pacientes foram as mesmas.; In this research, a evaluation of the retention of bimaxilar complete denture in function of the characteristics of the basal area by three calibrated experienced clinician was accomplished in 14 patients of the Odontology College of the University of São Paulo. The anterior vertical retention...

Avaliação da força de retenção de encaixes o'ring submetidos a soluções de higienização diárias; Evaluation of retention force of o'ring attachments subjected to daily hygiene solutions

Felipucci, Daniela Nair Borges
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 10/09/2013 PT
Relevância na Pesquisa
36.78%
Soluções auxiliares para higienização de próteses têm sido indicadas como método efetivo no controle de biofilme. Desta forma, este estudo teve por objetivo avaliar se as soluções (Cepacol/C, Cepacol Flúor/CF, Listerine/L, hipoclorito de sódio 0,05%/HS e água deionizada/AD, como controle) potencializam a perda de retenção do o'ring (Conexão Sistemas de Prótese Ltda). Foi obtida uma base de teflon com dois análogos e pilares o'ring e contra-bases, compostas pelas cápsulas metálicas e anéis, foram confeccionadas e divididas em grupos (n=6). Foram simulados 90 dias de imersão overnight, sendo obtido o valor da resistência à tração a cada 30 dias, utilizando a máquina de ensaios mecânicos (Material Testing System MTS 810), totalizando 4 leituras (T0, T1, T2 e T3). Foi realizada análise qualitativa por meio de microscopia eletrônica de varredura em um espécime de cada grupo. Os dados da força de retenção (N) foram analisados estatisticamente pelos testes ANOVA e Bonferroni (α=0,05). Os resultados demonstraram que a retenção diminuiu significativamente com o tempo (P=0,0001) e com o uso das soluções (P=0,0000) e houve interação entre os fatores de variação (P=0,0245). A retenção no T0 (11...

Oral manifestations of diabetes mellitus in complete denture wearers

de Lima, Danielle Cristina; Nakata, Gislaine Cristina; Balducci, Ivan; Almeida, Janete Dias
Fonte: Mosby-elsevier Publicador: Mosby-elsevier
Tipo: Artigo de Revista Científica Formato: 60-65
ENG
Relevância na Pesquisa
36.86%
Statement of problem. The oral mucosa has been reported to show a variety of changes in subjects with diabetes mellitus.Purpose. The purpose of this study was to compare diabetic and nondiabetic subjects wearing complete dentures with regard to salivary flow, salivary buffering capacity, denture retention, and oral mucosal lesions.Material and methods. Sixty subjects, 30 with and 30 without a diagnosis of diabetes, were matched for gender, race, and age. Salivary flow, salivary buffering capacity, glycemia, blood pressure, presence of mucosal lesions, denture retention, use of medications, and behavioral factors (controlled or uncontrolled diet, alcohol consumption, and smoking) reported by the subjects, were evaluated. For the salivary buffering capacity test, 1 mL of saliva was pipetted into a test tube containing 3 mL 0.005 N of hydrochloric acid, and the pH was measured with indicator strips. Group differences were statistically analyzed using the Student t test and the Mann-Whitney test for quantitative variables and the chi-square test for qualitative variables (alpha = .05).Results. Mean (SD) salivary flow was 1.14 (0.87) mL/min in the nondiabetic subjects and 0.95 (0.61) mL/min in the diabetic subjects. Evaluation of self-reported denture retention revealed no significant difference between groups. Denture retention was observed in 66.7% (20/30) of the control group and in 50% (15/30) of the diabetic group. The prevalence of mucosal lesions was 90% (27/30) in the control group and 83.3% (25/30) in the diabetic group. Salivary buffering capacity was 5.80 (0.85) in the control group and 5.26 (0.83) in the diabetic group (P = .017).Conclusions. Within the limitations of this study...

Effect of the surface treatment of plain carbon fiber posts on the retention of the composite core: an in vitro evaluation

Quintas, Adriana Ferreira; Bottino, Marco Antonio; Neisser, Maximiliano Piero; Araújo, Maria Auxiliadora Junho de
Fonte: Sociedade Brasileira de Pesquisa Odontológica e Faculdade de Odontologia da Universidade de São Paulo Publicador: Sociedade Brasileira de Pesquisa Odontológica e Faculdade de Odontologia da Universidade de São Paulo
Tipo: Artigo de Revista Científica Formato: 64-69
ENG
Relevância na Pesquisa
46.38%
Foi avaliado o possível efeito de tratamentos superficiais em pinos de fibra de carbono lisos, quando comparados aos pinos serrilhados, na retenção à resina composta empregada na confecção de núcleos de preenchimento. Foram utilizados cinqüenta pinos de fibra de carbono, divididos em cinco grupos: os quatro primeiros grupos eram constituídos por pinos do tipo liso, cujas superfícies foram tratadas, e o último grupo por dez pinos do tipo serrilhado. Foram desenvolvidas matrizes de resina acrílica com um leito ajustado para conter o pino, com um alargamento na porção coronária para posterior preenchimento com resina composta. Após o tratamento superficial, todos os pinos receberam camadas de primer, foram secos e então ajustados à matriz de resina, colocando-se a resina composta autopolimerizável na porção coronária para um núcleo de preenchimento de 3 mm. As amostras foram submetidas a termociclagem e armazenadas em água destilada por uma semana. Os espécimes foram testados por meio de ensaios mecânicos de tração, à velocidade de 0,5 mm/min, até o deslocamento do conjunto ou a fratura da resina do núcleo. As conclusões foram as seguintes: a) o tratamento superficial nos grupos tratados por meio de jateamento (Grupo A)...

Kinesiographic study of complete denture movement related to mucosa displacement in edentulous patients.

Compagnoni, Marco Antonio; Souza, Raphael Freitas de; Leles, Cláudio Rodrigues
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 356-361
ENG
Relevância na Pesquisa
46.77%
The mucosa that covers the residual ridges of edentulous patients may present some distortion or displacement when occlusal loading is applied in complete dentures. This distortion and movement of the denture can result in acceleration of residual ridge resorption and loss of retention and stability. The aim of this study was to analyze the pattern of upper complete denture movement related to underlying mucosa displacement. A sample of 10 complete denture wearers was randomly selected, which had acceptable upper and lower dentures and normal volume and resilience of residual ridges. The kinesiographic instrument K6-I Diagnostic System was used to measure denture movements, according to the method proposed by Maeda et al.7, 1984. Denture movements were measured under the following experimental conditions: (A) 3 maximum voluntary clenching cycles and (B) unilateral chewing for 20 seconds. The results showed that under physiological load, oral mucosa distortion has two distinct phases: a fast initial displacement as load is applied and a slower and incomplete recovery when load is removed. Intermittent loading such as chewing progressively reduces the magnitude of the denture displacement and the recovery of the mucosa is gradually more incomplete.

Complete denture wearing and fractures among edentulous patients treated in university clinics

Takamiya, Aline S.; Monteiro, Douglas R.; Marra, Juliê; Compagnoni, Marco A.; Barbosa, Debora B.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.66%
Objective: The prevalence of wearing and fracture of complete dentures was evaluated among edentulous patients treated in two dental schools in Brazil. Background: Acceptance and wearing of complete dentures are related to adaptive behaviour of edentulous patients. However, one reason that could interfere with the wearing dentures is their potential to fracture, which is still a common complication in denture rehabilitation practice. Material and methods: Two hundred and twenty-four edentulous patients rehabilitated with complete dentures from 2000 to 2005 in Araçatuba and Araraquara Dental School, University of State of São Paulo, were assessed in 2006 and 2007 to answer a questionnaire about wearing and fracture of their dentures. Statistical analysis were performed using Epi Info software and chi-squared test to compare maxillary and mandibular data (α = 0.05). Results: Almost 26% of the patients did not wear their dentures, and among the remainder, the majority wore the maxillary denture. About 30% of the dentures were fractured, with higher prevalence in the maxillary arch (p = 0.003). Conclusions: Discontinuation of wearing dentures was quite high, especially considering the treatment which was carried out in university clinics. Prevalence of fractures was also high...

Clinical and histopathological analysis of intramucosal zirconia inserts used for improving maxillary denture retention

Gonçalves,Fábio; Dias,Eliane Pedra; Cestary,Tania Mari; Taga,Rumio; Zanetti,Raquel Virgínia; Zanetti,Artemio; Granjeiro,José Mauro
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 EN
Relevância na Pesquisa
36.78%
Intramucosal inserts made of zirconia ceramic have been used for the rehabilitation of edentulous patients. This study aimed to follow up on patients with complete dentures having intramucosal zirconia inserts and to perform a histological analysis of biopsies of the epithelium surrounding the inserts. Twelve 31-66-year-old subjects of both genders received complete denture treatment having the intramucosal inserts in place. Detailed clinical, prosthetic and surgical procedures were described. Clinical exams were done on postoperative days 3, 7, 15, 120 and 360. One year after denture placement, the subjects received local anesthesia and the tissues surrounding the insertion sites in the alveolar ridge were removed using a scalpel blade. Biopsies were fixed for up to 48 h in 10% phosphate-buffered formaldehyde and 5-µm-thick sections were cut and stained with hematoxylin and eosin and Gomori Trichrome. Immunohistochemistry was used to identify endothelium (anti-CD3) and T lymphocytes (anti-CD31). Removing and reinserting the denture was painful until day 15, but all patients reported a marked increase in the retention and stability of the complete denture with little or no discomfort after 30 days. The histopathological analysis showed that zirconia inserts were well tolerated by the oral mucosa...

Influence of Inner Circular Sealing Area Impression Method on the Retention of Complete Dentures

Wang,Cun-Wei; Shao,Qi; Sun,Hui-Qiang; Mao,Meng-Yun; Zhang,Xin-Wei; Gong,Qi; Xiao,Guo-Ning
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2015 EN
Relevância na Pesquisa
56.76%
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.

Effect of the surface treatment of plain carbon fiber posts on the retention of the composite core: an in vitro evaluation

QUINTAS,Adriana Ferreira; BOTTINO,Marco Antonio; NEISSER,Maximiliano Piero; ARAÚJO,Maria Auxiliadora Junho de
Fonte: Sociedade Brasileira de Pesquisa Odontológica e Faculdade de Odontologia da Universidade de São Paulo Publicador: Sociedade Brasileira de Pesquisa Odontológica e Faculdade de Odontologia da Universidade de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2001 EN
Relevância na Pesquisa
46.38%
This study aims to evaluate the role of surface treatments performed on plain carbon fiber posts, in relation to serrated carbon fiber posts, in the retention of the composite core. Fifty carbon fiber posts received surface treatments in order to verify their influence on the retention of the core material. An acrylic resin mold was developed in order to precisely fit the post, leaving a machined space to accommodate a self-curing composite resin. After the surface treatment, a primer was applied on the coronal portion of all posts, which were then dried. They were fitted to the mold and received a 3 mm composite core. All specimens were thermocycled and then stored in distilled water for a week. Tension test was performed at a speed of 0.5 mm/min until there was lack of adhesion or fracture of the core. The conclusions were: a) the values of retention related to aluminum oxide spray (group A), depth cutter diamond burs (group C) and posts with machined coronal portion (group D) were comparable to those of serrated posts (group E), although no statistically significant difference between these groups was found; b) the mean values of core retention in group B (medium grit diamond burs) were statistically lower than those of other groups.

A Mathematical Derivation to Prove Reduced Denture Retention in V Shaped Palate

Mathew, Liji; Unni, K. N.; Vijayakumar
Fonte: Springer India Publicador: Springer India
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.74%
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.

Retenção de grampos cirucenferenciais associados a retentores intra-radiculares com encaixe era utilizados em overdentures parciais removíveis; Retention clips cirucenferenciais associated with CuAlZn with docking was used in removable partial overdentures

SOUZA, José Everaldo de Aquino
Fonte: Universidade Federal de Goiás; BR; UFG; Mestrado em Odontologia; Ciência da Saúde Publicador: Universidade Federal de Goiás; BR; UFG; Mestrado em Odontologia; Ciência da Saúde
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
36.8%
The overdentures can be defined as total or partial removable dentures that cover root or osseo integrated implants rehabilitating the whole dentition. The mechanical retention in the removable partial overdentures (RPOs) is obtained through the use of cast clasps and attachments. This biomechanical principle has a great importance, since is inwardly associated with long term behavior and clinical performance of prosthesis and consequently, with comfort and satisfaction of the patients. So, the aim of this study was to assess the retention of metallic framework with simple circumferential claps associated intraradicular retainer with attachment type ERA (Extra coronal Resilient Attachment, Sterngold Implamed, Attleboro, EUA) in function of the metals based cobalt-chromium alloy (Co-Cr), titanium commercially pure (Ti cp) and nickel-chromium with titanium alloy (Ni-Cr with Ti), of the retentive undercuts of 0,25mm and 0,75mm and in function of the time of use in each simulated period (initial, 6 months, 1, 2, 3, 4 e 5 years). Through of metallic matrices representing a partially edentulous mandibular right hemi-arch segment constituted by the crown of the first molar, root of the inferior canine and with the absent of the premolars...

Usage of denture adhesives

Coates, A.
Fonte: Elsevier Sci Ltd Publicador: Elsevier Sci Ltd
Tipo: Artigo de Revista Científica
Publicado em //2000 EN
Relevância na Pesquisa
46.67%
OBJECTIVES: There have been few reports in the dental literature on the number of denture wearers who regularly use denture adhesive. The objectives of this study were to see what the incidence of usage of denture adhesive was by a surveyed edentulous population, to determine the degree of success of its usage and the reasons for its current use or nonuse. METHODS: In this study, 146 patients attending the Adelaide Dental Hospital for denture treatment were surveyed regarding their usage of denture adhesive, using a prepared questionnaire. The surveyed group was divided into three categories--those who had never tried denture adhesive, those who had tried denture adhesive but no longer used it, and those who currently used denture adhesive. RESULTS: In the survey, there were 52 males (35.6%) and 94 females (64.4%) and 96 (65.7%) were over 60 years of age. Of these 78 patients (54.9%) had worn their dentures for 10 years or more, and 26 (17.8%) for 20 years or more. A total of 98 patients (67.1%) had never tried denture adhesive: 48 patients (32.9%) had tried denture adhesive but only 10 (6.9%) currently used it. Various reasons for trying denture adhesive and for its continued use or nonuse were given. CONCLUSIONS: In this study, 52% of patients surveyed saw no need for the use of denture adhesive as they managed their dentures well; 20.5% of patients did not know that denture adhesives existed; and 32.9% had tried denture adhesive but only 6.9% continued to use it on a regular basis.

Denture adhesives: A review

Coates, A.
Fonte: Australian Prosthodontic Society Inc. Publicador: Australian Prosthodontic Society Inc.
Tipo: Artigo de Revista Científica
Publicado em //1995 EN
Relevância na Pesquisa
46.5%
This review article explores the current status of denture adhesives. Their many uses are discussed with the philosophy of their use and their disadvantages and contra-indications. With an increase in the number of elderly edentulous patients, there is likely to be a greater demand for denture adhesives. Dentists will need to be more aware of the need to prescribe denture adhesives and manufacturers are encouraged to improve commercially available products.

Retention force of T-bar clasps for titanium and cobalt-chromium removable partial dentures

RODRIGUES, Renata Cristina Silveira; MACEDO, Ana Paula; TORRES, Érica Miranda de; MATTOS, Maria da Glória Chiarello de; RIBEIRO, Ricardo Faria
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.55%
The objective of this study was to evaluate the retention force of T-bar clasps made from commercially pure titanium (CP Ti) and cobalt-chromium (Co-Cr) alloy by the insertion/removal test simulating 5 years use. Thirty-six frameworks were cast from CP Ti (n=18) and Co-Cr alloy (n=18) with identical prefabricated patterns on refractory casts from a distal extension mandibular hemi-arch segment. The castings were made on a vacuum-pressure machine, under vacuum and argon atmosphere. Each group was subdivided in three, corresponding to 0.25 mm, 0.50 mm and 0.75 mm undercuts, respectively. No polishing procedures were performed to ensure uniformity. The specimens were subjected to an insertion/removal test and data was analyzed statistically to compare CP Ti and Co-Cr alloy in the same undercut (Student's t-test for independent samples) and each material in different undercuts (one-way ANOVA) (p=0.05). Comparisons between materials revealed significant differences (p=0.017) only for the 0.50-mm undercut. No significant differences (p>0.05) were found when comparing the same material for the undercuts. It may be concluded that for different undercuts, both Co-Cr alloy and CP Ti had no significant differences for T-bar clasps; CP Ti showed the lowest retention force values when compared to Co-Cr alloy in each undercut...

Wear of double crown systems: electroplated vs. casted female part

Bayer,Stefan; Kraus,Dominik; Keilig,Ludger; Gölz,Lina; Stark,Helmut; Enkling,Norbert
Fonte: Faculdade De Odontologia De Bauru - USP Publicador: Faculdade De Odontologia De Bauru - USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 EN
Relevância na Pesquisa
36.78%
OBJECTIVES: The wear of telescopic crowns is a common problem often reducing the patient's satisfaction with the denture and resulting in a renewal of the denture. The study aims to compare the wear behavior of conical crowns using electroplated copings (group E ) with standard telescopic crowns with cast female parts (group C). MATERIAL AND METHODS: 10 conical crowns were milled for each group of a cast gold alloy. The specimen of group E had a conicity of 2º. The cast secondary crowns of group C had a 0º design. The electroplated coping was established by direct electroforming. An apparatus accomplishing 10,000 wear cycles performed the wear test. The retentive forces and the correlating distance during insertion and separation were measured. The wear test was separated in a start phase, an initial wear phase and the long term wear period. The retention force value and the force-distance integral of the first 0.33 mm of each cycle were calculated. RESULTS: The retentive forces were significantly higher for group E and the integrals were significantly lower for this group except the integral at cycle 10,000. The changes of retention force and integral did not differ significantly between both groups in all phases. The change of the integrals as well as the integral at the particular cycles showed higher interquartile distances for group C. CONCLUSIONS: Within the limitations of this study the tested conical crowns showed clinically acceptable retentive properties. The values reached a range comparable to retentive elements tested in recent literature. The values of group C showed higher ranges. The force measured for group E was significantly higher than for group C but the integrals showed an opposite tendency. The results indicate that an exclusive analysis of the force is not sufficient as the integral is not equivalent to the force although it describes the retentive property of the system in a better way than the force over a distance is described. Both systems seem to be suitable for clinical practice.

Retention force of T-bar clasps for titanium and cobalt-chromium removable partial dentures

Rodrigues,Renata Cristina Silveira; Macedo,Ana Paula; Torres,Érica Miranda de; Mattos,Maria da Glória Chiarello de; Ribeiro,Ricardo Faria
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
Relevância na Pesquisa
46.55%
The objective of this study was to evaluate the retention force of T-bar clasps made from commercially pure titanium (CP Ti) and cobalt-chromium (Co-Cr) alloy by the insertion/removal test simulating 5 years use. Thirty-six frameworks were cast from CP Ti (n=18) and Co-Cr alloy (n=18) with identical prefabricated patterns on refractory casts from a distal extension mandibular hemi-arch segment. The castings were made on a vacuum-pressure machine, under vacuum and argon atmosphere. Each group was subdivided in three, corresponding to 0.25 mm, 0.50 mm and 0.75 mm undercuts, respectively. No polishing procedures were performed to ensure uniformity. The specimens were subjected to an insertion/removal test and data was analyzed statistically to compare CP Ti and Co-Cr alloy in the same undercut (Student's t-test for independent samples) and each material in different undercuts (one-way ANOVA) (p=0.05). Comparisons between materials revealed significant differences (p=0.017) only for the 0.50-mm undercut. No significant differences (p>0.05) were found when comparing the same material for the undercuts. It may be concluded that for different undercuts, both Co-Cr alloy and CP Ti had no significant differences for T-bar clasps; CP Ti showed the lowest retention force values when compared to Co-Cr alloy in each undercut...

Efeito do tratamento superficial de pinos de fibra de carbono lisos na retenção da resina de preenchimento: uma avaliação in vitro; Effect of the surface treatment of plain carbon fiber posts on the retention of the composite core: an in vitro evaluation

QUINTAS, Adriana Ferreira; BOTTINO, Marco Antonio; NEISSER, Maximiliano Piero; ARAÚJO, Maria Auxiliadora Junho de
Fonte: Universidade de São Paulo. Faculdade de Odontologia Publicador: Universidade de São Paulo. Faculdade de Odontologia
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artigo Avaliado pelos Pares Formato: application/pdf
Publicado em 01/03/2001 ENG
Relevância na Pesquisa
46.38%
Foi avaliado o possível efeito de tratamentos superficiais em pinos de fibra de carbono lisos, quando comparados aos pinos serrilhados, na retenção à resina composta empregada na confecção de núcleos de preenchimento. Foram utilizados cinqüenta pinos de fibra de carbono, divididos em cinco grupos: os quatro primeiros grupos eram constituídos por pinos do tipo liso, cujas superfícies foram tratadas, e o último grupo por dez pinos do tipo serrilhado. Foram desenvolvidas matrizes de resina acrílica com um leito ajustado para conter o pino, com um alargamento na porção coronária para posterior preenchimento com resina composta. Após o tratamento superficial, todos os pinos receberam camadas de "primer", foram secos e então ajustados à matriz de resina, colocando-se a resina composta autopolimerizável na porção coronária para um núcleo de preenchimento de 3 mm. As amostras foram submetidas a termociclagem e armazenadas em água destilada por uma semana. Os espécimes foram testados por meio de ensaios mecânicos de tração, à velocidade de 0,5 mm/min, até o deslocamento do conjunto ou a fratura da resina do núcleo. As conclusões foram as seguintes: a) o tratamento superficial nos grupos tratados por meio de jateamento (Grupo A)...

The influence of mandibular ridge anatomy on treatment outcome with conventional complete dentures

Ribeiro,Jaiane A.M; de Resende,Camila M.B.M; Lopes,Ana L.C; Farias-Neto,Arcelino; Carreiro,Adriana da F.P
Fonte: Acta Odontológica Latinoamericana Publicador: Acta Odontológica Latinoamericana
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2014 EN
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Since prognostic indicators are likely to take on increasing importance as a diagnostic tool for selection of patients for implant provision, this study investigated the influence of the shape and resiliency of the mandibular alveolar ridge on the retention and stability of conventional complete dentures. Ninety- three edentulous patients wearing both maxillary and mandibular conventional complete dentures composed the sample. Data were collected regarding shape and resiliencyof the mandibular residual ridge. Dentures were assessed for retention and stability using an objective and reproducible tool.The associations between the clinical characteristics of the mandibular alveolar ridge and denture retention and stability were analyzed using chi-square and Fisher exact tests (a = 0.05). A significant association between ridge shape and denture stability (p < 0.05) was found, while ridge resiliency was significantly associated to denture retention (p < 0.001). Based on the results, mandibular ridge shape and resiliency influenced the retention and stability of conventional complete dentures.