Influence of thermocyclic loading on the shear bond strength between denture teeth and denture base resin

• Grant number: 13/13529-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2013
• End date: August 31, 2014
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Fernanda de Carvalho Panzeri
• Grantee: Etiene Faria Aguiar
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The index of people who wear prosthesis in Brazil and worldwide is high. This is a kind of popular treatment. However, the materials used to this purpose have limitations, specially debonding of denture teeth out of acrylic resin bases. Therefore, the purpose of this study is to evaluate the shear bond strength between denture teeth to two types of acrylic denture base resin when submitted to thermocyclic loading. Forty mandibular molars will be processed by it's cervical portion, in two types of acrylic resin (heat-cured and microwave- cured). It will be used a metallic matrix that will be included in dental plaster in a muffle with the artificial teeth united to it by wax. After the the plaster stuck and the wax removal, the matrix will be removed from the muffle and the teeth will receive mechanical retentions and wet in acrylic monomer. After these, it's going to be included according to each study group. The process of polymerization will follow the manufacturer's instruction. The samples will be separated in two groups, according to the kind of the treatment which will be submitted ( with or without thermocyclic loading). The teeth will be submitted to 1.200.000 cycles (ER 37000 - Erios), with load of 98N and frequency of 2Hz/second, simulating 5 years of chew. Bond strength test will be performed in sample, by traction in a universal test machine (Emic, Model 1L-2000, 500N, 1mm/min).After the bond strength test, the results will be statistically analyzed using the best test according to the normality verified. Besides, the fracture standards will be analyzed.