Taxa de sobrevida, carga para fratura e análise por elementos finitos de dentes anteriores restaurados com facetas cerâmicas variando o desenho do preparo
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Data
2013-08-01
Autores
Bergoli, César Dalmolin [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo foi avaliar a taxa de sobrevida, carga para fratura e distribuição de tensões de incisivos centrais e caninos superiores restaurados com facetas cerâmicas variando o desenho do preparo. Trinta incisivos centrais superiores e trinta caninos superiores (N=60) foram selecionados para o estudo. Os espécimes foram embutidos até 3 mm da junção cemento esmalte e o ligamento periodontal simulado usando um material a base de poliéter. Após essa etapa os espécimes foram randomizados em quatro grupos (n=15) de acordo com o desenho do preparo e o tipo de dente: Gr1- Incisivo central com preparo conservador; Gr2- Incisivo central com preparo convencional com chanfro palatino; Gr3- Canino com preparo conservador; Gr4 – Canino com preparo convencional com chanfro palatino. Os espécimes foram restaurados com facetas cerâmicas a base de di-silicato de lítio, obtidas pela técnica da injeção. Os espécimes foram submetidos à 4.106 ciclos mecânicos (45º, 37oC, 100 N, 4 Hz) e avaliados quanto a possíveis falhas a intervalos de 500.000 ciclos. Ao final da ciclagem mecânica os espécimes que sobreviveram foram submetidos ao teste de compressão. Modelos semelhantes aos utilizados no teste laboratorial foram simulados bi-dimensionalmente (Rhinoceros® 4.0) e o comportamento mecânico avaliado (MSC.Patrans 2005r2 e.MSC.Marc 2005r2) através dos valores de Tensão Máxima Principal. As taxas de sobrevida dos corpos de prova foram calculadas pelo teste de Kaplan Meier e Log-rank (α=0.05) e os valores de carga para fratura pelo teste T-Student (α=0.05). Todos os grupos apresentaram taxas de 100 % de sobrevida, não havendo diferença estatística entre eles. O teste T-Student não mostrou diferença estatística para os diferentes desenhos de preparo, mas mostrou diferença para os diferentes dentes submetidos ao mesmo desenho de preparo. O teste de elementos finitos...
The aim of this study was to evaluate the survival rate, load to fracture and tensile distribution of human central incisors and canines restored with ceramic veneers varying the prepare design. Thirty human central incisors and thirty canines (N=60) were selected for the study. The specimens were embedded with acrylic resin up to 3 mm of the cemento/enamel junction and the periodontal ligament was simulated with polyether. After this step the specimens were randomized in four groups (n=15), based on the tooth prepare design and type of teeth: Gr1- Central incisor with a conservative prepare; Gr2- Central incisor with conventional prepare with palatine chamfer; Gr3- Canine with conventional prepare; Gr4 - Canine with conventional prepare with palatal chamfer. The specimens were prepared, molded and models with rock stone type IV were obtained. Ceramic veneers (IPS e.max Press, Ivoclar Vivadent, Schann) were confectioned. The veneers were adhesively cemented on specimens. The specimens were submitted to mechanical cycling (45o, 37oC, 100 N, 4 Hz, 4.000.000 cycles) and evaluated at each 500.000 cycles to detect any kind of failure. Specimens that survive to mechanical cycling were submitted to fracture resistance test. Identical models were draw bi-dimensionally (Rhinoceros® 4.0) and the mechanical behavior were evaluated (MSC.Patrans 2005r2 e.MSC.Marc 2005r2) by Maximum Principal Stress. The survival rate were evaluated by Kaplan-Meier test (α=0.05), while load to fracture values was evaluated by T-Student test (α=0.05). All groups showed same values of survival rate (100%). Same teeth showed same values of fracture load, independently the design of prepare. Different teeth, showed differences in the fracture load, when submitted to same design prepare. The laminate veneer with the palatal chamfer design showed higher Maximum Principal Stress values
The aim of this study was to evaluate the survival rate, load to fracture and tensile distribution of human central incisors and canines restored with ceramic veneers varying the prepare design. Thirty human central incisors and thirty canines (N=60) were selected for the study. The specimens were embedded with acrylic resin up to 3 mm of the cemento/enamel junction and the periodontal ligament was simulated with polyether. After this step the specimens were randomized in four groups (n=15), based on the tooth prepare design and type of teeth: Gr1- Central incisor with a conservative prepare; Gr2- Central incisor with conventional prepare with palatine chamfer; Gr3- Canine with conventional prepare; Gr4 - Canine with conventional prepare with palatal chamfer. The specimens were prepared, molded and models with rock stone type IV were obtained. Ceramic veneers (IPS e.max Press, Ivoclar Vivadent, Schann) were confectioned. The veneers were adhesively cemented on specimens. The specimens were submitted to mechanical cycling (45o, 37oC, 100 N, 4 Hz, 4.000.000 cycles) and evaluated at each 500.000 cycles to detect any kind of failure. Specimens that survive to mechanical cycling were submitted to fracture resistance test. Identical models were draw bi-dimensionally (Rhinoceros® 4.0) and the mechanical behavior were evaluated (MSC.Patrans 2005r2 e.MSC.Marc 2005r2) by Maximum Principal Stress. The survival rate were evaluated by Kaplan-Meier test (α=0.05), while load to fracture values was evaluated by T-Student test (α=0.05). All groups showed same values of survival rate (100%). Same teeth showed same values of fracture load, independently the design of prepare. Different teeth, showed differences in the fracture load, when submitted to same design prepare. The laminate veneer with the palatal chamfer design showed higher Maximum Principal Stress values
Descrição
Palavras-chave
Ceramica, Prótese dentária, Cimentos de resina
Como citar
BERGOLI, César Dalmolin. Taxa de sobrevida, carga para fratura e análise por elementos finitos de dentes anteriores restaurados com facetas cerâmicas variando o desenho do preparo. 2013. 91 f. Tese (doutorado) - Universidade Estadual Paulista Julio de Mesquita Filho, Instituto de Ciência e Tecnologia, 2013.