Effect of thermocycling protocols on the bond strength of a restorative composite

• Grant number: 16/19288-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2017
• End date: December 31, 2018
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Rubens Nisie Tango
• Grantee: Isabela Macêdo de Barros
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

The objective of this project will be to evaluate the effect of thermal ageing on the adhesive interface between human dentin and an indirect restorative material (ceramic-composite resin), by the microtensile test. Therefore, 10 human teeth will be prepared to receive the cement blocks of this indirect restorative material. The enamel and dentin surfaces will be treated with two adhesive systems (etchand-rinse and self-etching). The indirect restorative material will receive specific treatment recommended by the manufacturer (acid etching + silanization). The resin cement will be applied to the tooth structure and to control the standardization of cement thickness, 500g load will be applied on the set for 120seconds, when excess will be removed and performed the photo-activation. The set will be immersed in distilled water at 37 °C for 24 hours when the sets will be cut in a machine (ISOMET), to obtain i-shaped specimens (sp). The sp will be divided randomly into groups according to the temperature of the thermocycling (T1, T2, T3) in liquid solution - water (L1) As control groups, will be considered those ones stored in water (L1) and in mineral oil (L2), with no thermocycling. The sp will be thermalcycled (6,000 cycles) and then subjected to microtensile test. The fracture strength data (MPa) will be subjected to statistical analysis and fractures will be analyzed and classified in stereo between adhesive, cohesive and mixed. (AU)