Effectivity of Bulk-Fill Composite Resin Restorations

• Grant number: 16/16740-1
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2017
• End date: June 30, 2018
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: José Augusto Rodrigues
• Grantee: José Augusto Rodrigues
• Host Institution: Universidade Universus Veritas Guarulhos (Univeritas UNG). Guarulhos , SP, Brazil

Abstract

Considering the increasing use of bulk-fill composite resin in the dental field, which preset as advantage low polymerization shrinkage and allows their application in deep cavities in thicker layers, there are concerns if adequate polymerization are achieve. Inadequate polymerization can reduce the resistance to oral environment challenges and clinical performance. Thus, this project proposes to assess the resistance to degradation by microhardness test and evaluate the clinical performance in 12 months of class II restorations with Bulk-Fill composite resins with regular or low viscosity. To in vitro evaluation of degradation will be made 150 specimens (n= 10) that will be tested in a factorial design considering composite in 3 levels (conventional resin as control, bulk-fill composite with low and regular viscosity), in vitro degradation in 5 levels (immersion in 100% ethanol for 24 hours and 7 days and water immersion for 24 hours, 7 and 30 days), repeated measures of microhardness in 7 levels (at 0.5; 1.0; 1.5; 2.0; 2.5, 3.0 and 3.5mm from the irradiated surface), before and after challenge. For the clinical study 30 patients will be selected and it will be made 60 Class II restorations (n = 30) with bulk-fill resin composite with low and regular viscosity, 2 in each volunteer. The evaluation of clinical performance will be carried out by visual inspection, by two calibrated examiners, one week after the final polishing of the restoration and after 6 and 12 months using the modified USPHS criteria. If the data show normal distribution parametric tests will be applied, otherwise they will be tested by nonparametric tests with 5% of significance level. (AU)