Fadiga de grampos de retenção em prótese parcial removível. Efeito de ligas, espessuras e técnicas de fusão. Parte I.

The authors looked for the verification of the fatigue of retentive clasps utilized on the removable partial denture. According to this, it was idealized and built on assay machine, that through movements, simulate the insertion and removal of the clasp for a pattern tooth, manufactured on cobalt-chromium which has all the preparation normally utilized to the correct confection of this type of prosthesis. It was utilized three different commercial alloys based on cobalt-chromium: L1-Biosil; L2-Steldent; L3-Duracron. It was utilized the T clasp of Roach, with was tested upon three different proportions among width and thickness: E1-1.7;E2-2.0 and E3-2.3 and was casted through two casting techniques: F1-oxygen-gas and F2-oxygen-acetylene. The clasps were tested on the machine, which allowed the reading of the number of insertion and removal cycles made until fatigue appeared. The obtained results were submitted to the statistic analysis and the authors concluded that: a) L3 (Duracrom) obtained the best results followed by L1 (Biosil) and finally L3 (Steldent); b) among the analyzed thickness, the best results were obtained by E3, followed by E2 and after this E1; c) form the casting techniques, F2 gave us the best results.

Shear bond strength fatigue limit of rest seats made with dental restoratives

Purpose: This study compared the shear bond strength (SBS) to enamel of rest seats made with a glass-ionomer cement (Fuji IX GP Fast), a resin-modified glass-ionomer cement (Fuji II LC), and a composite resin (Z100 MP) under monotonic and cyclic loading. Materials and Methods: Rest seats were built up onto the lingual surfaces of 80 intact human mandibular incisors. Specimens (n=10) were stored in distilled water at 37°C for 30 days and subjected to shear forces in a universal testing machine (0.5 mm/min) until fracture. The SBS values were calculated (MPa) using the bonding area (9.62 mm2) delimited by adhesive tags. A staircase approach was used to determine the SBS fatigue limit of each material. Specimens were submitted to either 10,000 cycles (5 Hz) or until specimen fracture. A minimum of 15 specimens was tested for each material. Scanning electron microscopy was used to examine the mode of failure. Data were statistically analyzed with one-way ANOVA and Tukey HSD tests (α = 0.05). Results: Z100 MP yielded higher (p < 0.05) SBS (12.25 MPa) than Fuji IX GP Fast (7.21 MPa). No differences were found between Fuji II LC (10.29 MPa) and the other two materials (p > 0.05). Fuji II LC (6.54 MPa) and Z100 MP (6.26 MPa) had a similar SBS limit. Fuji IX GP Fast promoted the lowest (p < 0.05) SBS fatigue limit (2.33 MPa). All samples showed cohesive failure patterns. Conclusion: Fatigue testing can provide a better means of estimating the performance of rest seats made with dental restoratives.

Evaluation of temporomandibular joint noise in partially edentulous patients.

In order to evaluate the presence of TMD (temporomandibular disorder), dissatisfaction related to the use of removable partial dentures (RPD) and the effect of the treatment on temporomandibular joint noises, 13 female patients with Kennedy class I and II mandibular arch were selected. Another 13 young, asymptomatic, dentate patients, also female, were used as reference. After four years, 38.4% were found to have a moderate or severe degree of TMD. Over the four years, the degree of TMD increased in 46.15% of the patients, was not affected in 20.07%, while in 15.38% it decreased or the patients remained free from signs and symptoms. About 30% of the patients at the second year and 46% after the fourth year, had complaints regarding retention and stability. It was concluded that there is no relationship between TMD and the condition of partially edentulous Kennedy class I and II, but patient dissatisfaction increased after the second year and temporomandibular joint noise was reduced significantly with the replacement of the teeth.

Severe fracture of the maxillary alveolar process associated with extrusive luxation and tooth avulsion: A case report

Aim: The aim of this report is to present a case of severe fracture of the maxillary anterior alveolar process with substantial bone dislodgement associated with extrusive tooth luxation and avulsion. Background: Dentoalveolar trauma is a challenge to dentistry, especially in young patients, for it can lead to early tooth loss which compromises oral function, esthetics, self-esteem, and alter the long-term plan of care for the victim. Case Report: A 12-year-old girl with severe dentoalveolar trauma to the maxillary anterior region presented for emergency care for her injury. Treatment consisted of fracture reduction of the alveolar process, repositioning of the teeth that had suffered extrusive luxation, placement of a semi-rigid splint, and suturing of soft tissue lacerations. The traumatized teeth presented with pulpal necrosis and were treated endodontically. After 24 months of follow up, the fracture of the alveolar process was completely healed and the displaced teeth presented no signs of ankylosis or root resorption. Summary: First-aid care contributed remarkably to this case allowing the re-establishment of esthetics, function, and patient's self-esteem. In spite of trauma extension the treatment outcomes were favorable. Clinical Significance: Cases of dentoalveolar trauma should be evaluated on an individual basis. However, early emergency management and adequate follow-up can prevent further complications and contribute to treatment success.

Effect of accelerated aging on the microhardness and color stability of flexible resins for dentures

Acrylic resins have been widely used due to their acceptable esthetics and desirable characteristics such as easy handling, good thermal conductivity, low permeability to oral fluids and color stability. Flexible resins were introduced on the market as an alternative to the use of conventional acrylic resins in the construction of complete and partial removable dentures. Although these resins present advantages in terms of esthetics and comfort, studies assessing chromatic and microhardness alterations of these materials are still scarce in the related literature. The aim of this study was to evaluate the chromatic and microhardness alterations of two commercial brands of flexible resins in comparison to the conventional resin Triplex when submitted to accelerated aging. The resins were manipulated according to manufacturers' instructions and inserted into a silicone matrix to obtain 21 specimens divided into 3 groups: Triplex, Ppflex and Valplast. Triplex presented the highest microhardness value (p < 0.05) for all the aging periods, which was significantly different from that of the other resins, followed by the values of Valplast and Ppflex. Comparison between the flexible resins (Ppflex and Valplast) revealed a statistically significant difference (p < 0.05) as regards color. The flexible resin Ppflex and the conventional resin Triplex presented no statistically significant difference (p < 0.05) as regards aging. The accelerated aging significantly increased the microhardness values of the resins, with the highest values being observed for Triplex. Valplast presented the greatest chromatic alteration after accelerated aging.

Oral health of the elderly with Alzheimer's disease

Objective: The objective of this study was to describe the oral health of elderly people diagnosed with Alzheimer's disease (AD). Study Design: Thirty elderly subjects with AD (mild, moderate, and severe) and 30 without AD (controls) were included in the study. Volunteer-reported oral health data were collected using the General Oral Health Assessment Index (GOHAI). Demographic and oral characteristics were assessed, including the number of natural teeth; number of decayed, missing, and filled teeth (DMTF); oral health index (OHI); removable prosthesis conditions; and oral pathologies. Results: GOHAI values were similar for both groups. Compared with the controls, the subjects with AD had a higher age, DMTF, OHI, and number of oral pathologies and a lower educational level and number of natural teeth. Conclusions: Elderly subjects with AD had poorer oral health than those without the disease. Despite the positive self-perception of their oral health, the oral health of subjects with AD tended to decline as their disease progressed. © 2012 Elsevier Inc.

Avaliação da influência do diâmetro e comprimento do implante osseointegrado associado à PPR Classe I mandibular pelo método dos elementos finitos

Pós-graduação em Odontologia - FOA

Influência dos sistemas de retenção e da inclinação do rebordo residual em casos de próteses conjugadas Classe I mandibular: análise da distribuição das tensões pelo método da fotoelasticidade

Pós-graduação em Odontologia - FOA

Avaliação do nível de inserção óssea do dente suporte em prótese parcial removível mandibular classe I associada a implante osseointegrado: análise pelo método dos elementos finitos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desordens temporomandibulares em usuários de prótese parcial removível: prevalência de acordo com a classificação de Kennedy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Planejamento em reabilitação oral: restabelecimento da relação intermaxilar por meio de prótese provisória overlay

The present article describes the treatment planning and fabrication of overlay denture to restore the jaw relationship in a partial edentulous patient with bruxism. A male patient, 51 years old, was referred to the oral rehabilitation clinic complaining about the chewing and aesthetic. The occlusal surface of the superior teeth presented severe wear. The fabrication of an interim overlay denture to restore the jaw relationship was planned. The overlay had metallic projections and covered the occlusal surface of superior teeth. After overlay insertion both function and aesthetic of the patient were recovered. It was concluded that the use of overlay improved the physiological normal position of the jaw and could provide a favorable prognosis for a definitive oral rehabilitation with implant-supported fixed denture.

Cementation of Prosthetic Restorations: From Conventional Cementation to Dental Bonding Concept

The cementation procedure of metal-free fixed partial dentures exhibits special characteristics about the porcelains and cementation agents, which turns the correct association between these materials necessary. Our purpose in this literature review was to point the main groups of cements associated to metal-free restoration and discuss about the advantages, disadvantages, and recommendations of each one. Our search was confined to the electronic databases PubMed and SciELO and to books about this matter. There are essentially 3 types of hard cement: conventional, resin, or a hybrid of the two. The metal-free restorations can be fixed with conventional or resin cements. The right choice of luting material is of vital importance to the longevity of dental restorative materials. Conventional cements are advantageous when good compressive straight, good film thickness, and water dissolution resistance are necessary. However, they need an ideal preparation, and they are not acid dissolution resistant. Conventional cements are indicated to porcelains that cannot be acid etched. Resin cements represent the choice to metal-free restoration cementation because they present better physical properties and aesthetic than conventional agents.

Regional odontodysplasia: Case report

Regional odontodysplasia (RO) is a rare developmental anomaly involving both mesodermal and ectodermal dental components in a group of contiguous teeth. It affects the primary and permanent dentitions in the maxilla and mandible or both jaws. Generally it is localized in only one arch. The etiology of this dental anomaly is uncertain. Clinically, affected teeth have an abnormal morphology, are soft on probing and typically discolored, yellow or yellowish-brown. Radiographically, the affected teeth show a ghostlike appearance. This paper reports the case of a 5-year-old girl presenting this rare anomaly on the left side of the maxillary arch, which crossed the midline. The primary maxillary left teeth (except for the canine) and the primary maxillary right central incisor were missing due to previous extractions. The permanent teeth had a ghostlike appearance radiographically. The treatment performed was rehabilitation with temporary partial acrylic denture and periodic controls. In the future, the extraction of affected permanent teeth and rehabilitation with dental implants will be evaluated. The presentation of this case adds valuable information to pediatric dentists to review special clinical and radiographic features of RO, which will facilitate the diagnosis and treatment of patients with this condition.

Avaliação clínica e microbiológica do tratamento da estomatite protética com tintura de Schinus terebinthifolius Raddi (Aroeira)

Objective: To evaluate the clinical efficacy of Schinus terebinthifolius Raddi (aroeira) tincture in the treatment of denture stomatitis. Method: Eighteen removable denture wearers with clinical diagnosis of type II denture stomatts and presence of candidosis associated to the denture use, as confirmed by clinical and mycological examinations, were selected for the study. The patients were allocated to two groups: TG (test group) - treatment with Schinus terebinthifolius Raddi (aroeira) tincture; CG (control group), treatment with nystatin. All patients were instructed to clean the dentures with toothbrush and dentifrice, and then apply the product on the palatal mucosa and on denture surface 3 times a day, during 15 consecutive days, removing the denture at bedtime and keeping it in a receptacle with water. At the 15th day of use, the clinical and mycological examinations were redone to evaluate treatment efficacy. Data were analyzed statistically by Wilcoxon and Mann-Whitney tests at 5% significance level. Results: The inflammatory process and Candida spp. infect on were eliminated in 66.7% and 77.8% of the cases, respectively, in TG. In CG, elimination of the inflammatory process and fungal infect on occurred in 77.8% and 88.9% of the cases, respectively. These results were statistically significant (p=0.01). There was no statistically significant difference between the treatments (p>0.05). In all cases, fungal infect on was detected only on the denture, and C. albicans was the most prevalent microorganism, being present in 94.4% of the cases. Conclusion: The treatment with Schinus terebinthifolius Raddi (aroeira) tincture was effective in the treatment of denture stomatitis, promoting remission of the inflammatory process and Candida spp infection.

Avaliação do ensino na clínica integrada da Faculdade de Odontologia de Araraquara - UNESP em função do planejamento global de tratamento e sua execução

Pós-graduação em Ciências Odontológicas - FOAR