Retention strength of cobalt-chromium vs nickel-chromium titanium vs CP titanium in a cast framework association of removable partial overdenture.

AIM: There is little information considering the framework association between cast clasps and attachments. The aim of this study was to evaluate the retention strength of frameworks match circumferential clasps and extra resilient attachment cast in three different alloys (cobalt-chromium, nickel-chromium titanium and commercially pure titanium), using two undercut (0.25 and 0.75 mm) and considering different period of time (0, 1/2, 1, 2, 3, 4 and 5 years). METHODS: Using two metallic matrices, representing a partially edentulous mandibular right hemiarch with the first molar crown, canine root and without premolars, 60 frameworks were fabricated. Three groups (n = 20) of each metal were cast and each group was divided into two subgroups (n = 10), corresponding the molar undercut of 0.25 mm and 0.75 mm. The nylon male was positioned at the matrix and attached to the acrylic resin of the prosthetic base. The samples were subjected to an insertion and removal test under artificial saliva environment. RESULTS: The data were analyzed and compared with ANOVAs and Tukey's test at 95% of probability. The groups cast in cobaltchromium and nickel-chromium-titanium had the highest mean retention strength (5.58 N and 6.36 N respectively) without significant difference between them, but statistically different from the group cast in commercially pure titanium, which had the lowest mean retention strength in all the periods (3.46 N). The association frameworks using nickel-chromium- titanium and cobalt-chromium could be used with 0.25 mm and 0.75 mm of undercut, but the titanium samples seems to decrease the retention strength, mainly in the 0.75 mm undercut. The circumferential clasps cast in commercially pure titanium used in 0.75 mm undercuts have a potential risk of fractures, especially after the 2nd year of use. CONCLUSION: This in vitro study showed that the framework association between cast clasp and an extra resilient attachment are suitable to the three metals evaluated, but strongly suggest extra care with commercially pure titanium in undercut of 0.75 mm. CLINICAL SIGNIFICANCE: Frameworks fabricated in Cp Ti tend to decrease in retentive strength over time and have a potential risk of fracture in less than 0.75 mm of undercut.

Prótese parcial removível overlay: fundamentos clínicos e relatos de casos / Overlay removable partial denture: underluing principles and cases reports

A prótese parcial removível (PPR) de recobrimento oclusal, também conhecida como PPR overlay, se caracteriza por recobrir a face oclusal de um ou mais dentes, podendo até mesmo recobrir as oclusais de todos os dentes posteriores e as incisais dos dentes anteriores para apoio ou sustentação. O presente trabalho teve como objetivo revisar os princípios envolvidos na sua indicação clínica, planejamento e execução, com o objetivo de discutir a viabilidade clínica e efetividade deste tipo de tratamento, identificando suas indicações, vantagens e desvantagens através da apresentação de casos clínicos. Concluiu-se que a PPR overlay pode ser indicada como alternativa de tratamento para situações especiais de arcadas parcialmente desdentadas, em pacientes com necessidade de alteração da dimensão vertical e/ou realinhamento do plano oclusal, podendo ser empregada como tratamento temporário ou definitivo. Apresenta como vantagens principais a maior simplicidade do tratamento, reversibilidade e custo relativamente baixo. No entanto, estudos adicionais são necessários para assegurar a viabilidade clínica e efetividade deste tipo de tratamento.

Overlay removable partial denture (RPD) is a prosthesis that recovers and uses for support, the occlusal surface of teeth, or even the occlusal of all posterior teeth and incisal edge of the anterior teeth. This review presents and discusses clinical and technical aspects involved in treatment with overlay partial dentures. It was concluded that overlay RPD can be indicated as an alternative treatment for partially edentulous patients who present reduced vertical dimension and changes of the occlusal plan. Treatment may be a definitive or temporary solution. The main advantages of overlay RPD are technical simplicity, reversibility and relative low cost. However, additional studies are needed to assure clinical viability and effectiveness of this treatment.

Implantes osseointegráveis em áreas com levantamento do seio maxilar e enxertos ósseos / Osseointegrated implants in maxillary sinus-lift and bone graft areas

Objetivos: Avaliar o índice de satisfação do tratamento com implantes osseointegráveis associados à enxertia óssea; fornecer dados estatísticos sobre esse índice e esclarecer à comunidade odontológica o possível contentamento manifestado pelo grupo assistido sobre a intervenção executada. Métodos: Os valores correlativos às análises, após aplicação do questionário, foram tabulados e, em seguida, foi aplicado cálculo estatístico (Teste Exato de Fisher e Teste Qui Quadrado) com nível de significância 5% (p<0,05). Resultados: De acordo com os dados obtidos, verificou-se que o grau de satisfação dos pacientes não fumantes foi significativamente maior que o do grupo de fumantes, independentemente da sua condição econômica. Quanto ao gênero, o índice de satisfação do sexo feminino assumiu um maior percentual em relação ao masculino. A necessidade de cirurgia complementar, a perda do enxerto ósseo e a repetição do ato cirúrgico, nesse estudo, não ocorreram com frequência. Todos os pacientes ficaram satisfeitos quanto ao ato cirúrgico executado, sendo que a maioria não necessitou de cirurgia complementar. Conclusão: Tendo em vista os fatores avaliados nesse estudo, pôde-se concluir que uma parcela significativa dos pacientes atendidos nos Cursos de Aperfeiçoamentos e Especialização em Implantodontia da Faculdade de Odontologia da Universidade Federal de Goiás, a partir do ano de 2004, relatou que as técnicas de instalação de implantes osseointegráveis e dos enxertos ósseos são procedimentos considerados traumáticos, mas, apesar disso, tiveram uma melhora significativa em relação à qualidade de vida após o tratamento.

Objectives: To assess the satisfaction index of such treatment; provide statistical data about this index and explain to the dental community, the possible satisfaction expressed by the group assisted, with regard to the intervention performed. Methods: After applying the questionnaire, the values of the analysis obtained were tabulated and statistical calculation was then applied (Fisher Exact test and Chi-Square test) with a significance level of 5% (p <0.05). Results: According to the data obtained, it was found that the degree of satisfaction of nonsmoker patients was significantly higher than that of the group of smokers, irrespective of their economic condition. As regards gender, the satisfaction index of women showed a higher percentage than that of men. In this study, the need for additional surgery, the loss of bone graft and repetition of the surgical procedure did not occur frequently. All patients were satisfied with the surgery performed, and the majority did not need additional surgery. Conclusion: In view of the factors evaluated in this study, it could be concluded that a significant portion of patients attended by the Improvement and Specialization Courses in Implant Dentistry at the Faculty of Dentistry, Federal University of Goiás, as from the year 2004, reported that the osseointegrated implant placement techniques and bone graft procedures are considered traumatic, but nevertheless they experienced a significant improvement in their quality of life after treatment.