Bond strength evaluation of different treatments for high viscosity Bulk Fill resin composites repair

• Grant number: 16/25480-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2017
• Effective date (End): December 31, 2017
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Sergio Kiyoshi Ishikiriama
• Grantee: Pedro Henrique Kazedani Nakashima
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

The use of bulk fill resin composites has been gradually increased due the studies that have shown good results of these materials in relation to polymerization contraction, degree of conversion and depth of cure. However, high viscosity bulk fill resin composites are recommended for direct use without coverage and are susceptible to fracture and wear. Thus, this study in vitro will evaluate the bond strength of a high viscosity bulk fill resin composite repair with different materials and different surface treatments. This study will present two variation factors: 1 - Resin composites divided into four levels: Filtek" Bulk Fill; Filtek" Z350 XT; Filtek" Z350 XT Flow; Filtek" Bulk Fill Flow; 2- Surface treatments divided into four levels: No treatment - negative control; surface roughness and adhesive; surface roughness, silane and adhesive; fluoridric acid, silane and adhesive. The response variable will be the bond strength obtained through microshear test, complemented by fracture analysis. High viscosity bulk fill resin composite blocks of 49 mm³ will be made and divided in 4 groups according to the proposed surface treatments. On the treated surfaces, four pins with different materials will be homogeneously distributed and adhered to. The blocks will be stored for 24 hours on deionized water and after that period, the specimens will be attached to a testing machine (Instron 3342) for the microshear test. Data will be analyzed according to the distribution and homogeneity of values, and then, submitted to the most appropriate statistical test by comparison between groups (p<0,05). (AU)