Evaluation of microhardness and surface roughness of composite resins sealed under different concentrations of bleaching gels

• Grant number: 11/18410-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2012
• End date: December 31, 2012
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Flávio Henrique Baggio Aguiar
• Grantee: Michele de Oliveira Lima
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

This study will evaluate the surface roughness and hardness of two dental composites: micro-hybrid and nanoparticles, sealed on their surface and subjected to the action of bleaching agents in concentrations of 6% and 35%. Will be made 80 test specimens, cured with LED light 2nd generation (Bluephase 16 i-Ivoclar Vivadent) with a light intensity of 1600 mW/cm2.The samples will be divided into 8 groups (n = 5 each), 40 samples for the study of roughness and 40 samples for the study of microhardness according to the type of composite in two levels (micro-hybrid Z-250 - 3M Espe and nanoparticles Z-350 - 3M Espe) use or non-sealing surface (Biscover LV -Bisco Ind., Schaumburg, IL, USA) and whitening procedures in two levels (hydrogen peroxide and 6% hydrogen peroxide 35%). After curing is done polish the samples with aluminum oxide discs Soflex (3M Espe) with decreasing grain then apply the sealant surface in certain groups. Two readings will be made (L1 and L2) of the surface roughness and microhardness. The read L1 will be made 24 hours after the preparation of samples and the read L2 after the application of bleaching agents. The results will be statistically analyzed.(AU)