Bond strength of low-shrinkage composite restorations after mechanical and thermal cycling

• Grant number: 15/25667-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2016
• End date: January 31, 2017
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Ticiane Cestari Fagundes
• Grantee: Erika Kiyoko Chiba
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

The technology has enabled that properties of restorative systems present improvements, particularly in cases of direct procedures in posterior teeth. The aim of this in vitro study will be to evaluate the microtensile bond strength (¼TBS) to dentin of Class I restorations, using three different restorative systems. Occlusal cavities will be performed in ninety-six human third molars. The specimens will be randomly divided into four groups (n=24), according to the restorative system: Scotchbond Universal + Filtek Z350 XT (3M/ESPE); Scotchbond Universal + Filtek Bulk Fill (3M/ESPE); AdheSE + Tetric Evo-Ceram (Ivoclar Vivadent) and AdheSE + Tetric Evo-Ceram Bulk Fill (Ivoclar Vivadent). After the restoration of cavities, the teeth will be divided into three subgroups (n=8): GI - 24hrs of storage (control group); GII -submitted to mechanical cycling and GIII - submitted to thermal cycling. Then according to the restorative system, the teeth will be cut into sticks 0.8mm2, totaling about 3-4 sticks for tooth. At the end of the challenges, the specimens will be submitted to ¼TBS test at speed of 0.5 mm/min, the values will be obtained in MegaPascal (MPa). Means of microtensile bond strength values will be submitted to two-way analysis of variance and Fisher's test for multiple comparisons, at 5% level of significance.