Evaluation of the interaction between adhesive systems and resin cements on tensile strength and Knoop hardness

• Grant number: 05/03100-0
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2005
• End date: November 30, 2006
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Luis Alexandre Maffei Sartini Paulillo
• Grantee: Luis Alexandre Maffei Sartini Paulillo
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

The purpose of this study is to investigate the interaction between "all-in-one" self-etching adhesive systems and resin cements used to cement glass fiber posts. The tensile strength and Knoop hardness will be determined. Sixty bovine teeth will be selected and stored in sodium chloride 0,9% during all the experiment. The teeth will be sectioned perpendicular to their long axis with a length of 17 mm. The root canals will have a diameter smaller than Largo`s (#5) diameter. The roots will be randomly divide into six groups: group 1: one-step self-etch adhesive (Xeno III) + resin cement (RelyX) + glass fiber post Reforpost 3; group 2: two-step self-etch adhesive (Single Bond Sistem) + resin cement (RelyX) + glass fiber post Reforpost 3; group 3: just resin cement (RelyX) + glass fiber post Reforpost 3; group 4: one-step self-etch adhesive (Xeno III) + resin cement (RelyX); group 5: two-step self-etch adhesive (Single Bond Sistem) + resin cement (RelyX); group 6: just resin cement (RelyX). The root canals will be endodontically prepared with the step-back technique. The gutta percha will be cut with Gates-Gliden number 5 and the canal prepared with Largo number 5 on an unique movement, in a depth of 12 mm. The canal will be cleaned with distilled water and dry with absorbent paper. Each specimen will be embed in resin and after the post cementation, the samples will be teste in tension in a universal-testing machine (EMIC - model DL 5000). A compressive load will be applied to the long axis of the tooth at a crosshead speed of 0,5mm/min. For Knoop microhardness testing the roots will be sectioned in equal thirds: apical, middle and cervical, with 3 mm each. In each part, the surface microhardness of the resin cement will be evaluated. The results will be compared and statistically analyzed. (AU)