Luiz Gustavo Dias Daroz

Adhesive bonding of resin cements to cast titanium with adhesive primers

The purpose of this study was to evaluate the effects of adhesive primer applications on the bond strength of resin cements to cast titanium. Four adhesive primers - Metaltite, Metal Primer II, Alloy Primer and Ceramic Primer - and their respective resin cements - Bistite II DC, Link Max, Panavia F 2.0, RelyX Unicem and RelyX ARC - were tested. Cast plates were prepared from titanium ingots (n=6 specimens/cement) and had their surfaces airborne-particle abraded with Al2O3 (50 μ m). Three resin cement cylinders were built on each bonded titanium surface, using a cylindrical translucent tubing mold and were subjected to micro-shear testing. Data were analyzed statistically by two-way ANOVA and Tukeys post-hoc test (α=0.05). The application of Metal Primer II and Ceramic Primer resulted in significant higher bond strength for Link Max and RelyX Unicem resin cements, respectively, than nonuse of adhesive primers. Panavia F 2.0 and RelyX ARC yielded high bond strength means with or without adhesive primers. The use of adhesive primers might increase the bond strength to cast titanium depending on the resin cement used.

Resistência de união de diferentes cimentos resinosos a cerâmica à base de dissilicato de lítio

Introduction: The success of indirect restorations depends on the union between cement and dental substrate. Therefore, the selection and knowledge of the characteristics of cement is important for the retention of indirect restoration. Objective: Is to evaluate the bond strength of two different resin cements to ceramic lithium disilicate. Methodology: Two experimental groups were made: conventional resin cement (CRC Group) and self-adhesive resin cement (CRA Group). With this, 10 lithium disilicate ceramics discs (10 mm) were prefabricated and on each disc were made 04 cement posts (0.7×1.0 mm), yielding a total of 20 samples of each type of cement. The disks had the same surface treatment for both groups, which is standard for the rich silica ceramic according to the protocol established by the manufacturer. The samples were submitted to microshear test to evaluate the bond strength between the cement and ceramics. Subsequently, the fail mode was analyzed in an optical microscope. Result: Data were subjected to statistical analysis. It was observed that the CRC group had a higher bond strength (15.29 MPa) compared to CRA group (12.41 MPa). In the analysis of fail mode, neither samples obtained adhesive fracture. In both groups, CRC (75%) and CRA (65%) it was obtained more failures of the mixed type, followed by the cohesive failure. Conclusion: Both cements showed adhesion on ceramic. The conventional resin cement showed better adherence to the ceramic base of lithium disilicate than the self-adhesive resin cement. Descriptors: Ceramics; shear strength; cementation; resin cements; dental prosthesis.

Formação profissional em odontologia: contribuição do programa atendimento à saúde bucal para a população de baixa renda – Vitória-ES

As atividades extramuros possibilitam aos alunos o conhecimento das dimensoes estruturais dos servicos publicos de saude, a participacao no atendimento a populacao, a compreensao das politicas de saude bucal, do papel do cirurgiao-dentista e do contexto social no qual futuramente o academico ira ingressar. O objetivo deste trabalho e apresentar o Programa de Extensao “Atendimento a Saude Bucal para Populacao de Baixa Renda”, salientando a sua importância na formacao dos academicos do Curso de Odontologia da Universidade Federal do Espirito Santo (UFES). Esse projeto vem contribuindo ha 34 anos para a formacao dos academicos dessa instituicao, possibilitando o conhecimento do contexto social de uma populacao desfavorecida financeiramente e o desenvolvimento de habilidades adquiridas na universidade. Conclui-se que projetos como esse sao de suma importância para a formacao de um profissional consciente das reais necessidades da populacao da regiao onde estara atuando, capaz de atender essa demanda com etica e profissionalismo.

Correlação entre o desajuste marginal e a tensão gerada sobre os implantes

A inducao de tensoes ao implante e ao tecido osseo peri-implantar pode ser responsavel pela reabsorcao tecidual e pela perda do implante. Proteses com o minimo desajuste marginal sao desejadas, acreditando-se na geracao de menores valores de tensao as fixacoes. No entanto, nao se tem certeza desta correlacao, uma vez que a literatura nao apresenta resultados confiaveis que venham a elucidar tal aspecto. Assim, o objetivo deste trabalho foi verificar se existe correlacao entre os valores de desajuste marginal e de tensao gerados as fixacoes pelo parafusamento de infraestruturas implanto-retidas. Foram obtidas dez infraestruturas em titânio fundido, utilizando-se matriz metalica contendo dois implantes conectados a pilares conicos para construcoes multiplas. As infraestruturas foram aleatoriamente avaliadas quanto aos desajustes marginais mediante o teste do parafuso unico e observacao em microscopio otico (120X). As tensoes nas fixacoes foram avaliadas por extensometria. A media de desajuste marginal foi 118,07 (58,61) μm e a media de tensao, 580,06 (253,93) gf. O teste de Pearson foi utilizado, mostrando nao haver correlacao entre desajuste marginal e tensao (-0,072), com p = 0,842. A presenca e a intensidade do desajuste marginal, por si so, nao sao indicadores seguros no prognostico da geracao de tensoes as fixacoes.