Influência de solução alcoólica na microdureza, rugosidade superficial e plasticização de resinas bulk fill

Abstract

The aim of this laboratory research was to evaluate 4 bulk fill resins, being 2 of regular viscosity and 2 of low viscosity, for microhardness Knoop, surface roughness and the effect caused by alcohol on their properties, including the degree of plasticization of each one. For this 10 specimens were made for each resin tested in acrylic matrix, 5mm in diameter and 4mm thick and 10 of the conventional resin in acrylic matrix of 5mm in diameter and 2mm in thickness (control group) for each of the tests (microhardness and surface roughness). Samples were tested before and after immersion in absolute alcohol for 24h. The results were statistically analyzed and it was observed that the low viscosity bulk fill resins presented lower microhardness than the other resins tested; that the amount of inorganic particles was directly proportional to microhardness and inversely proportional to surface roughness; that the bulk fill resins tested did not achieve even the clinically acceptable base/top hardness ratio (80%) even at the indicated light exposure and thickness; that the plasticization of composite resins is related to their polymerization; and as for surface roughness the composite resins tested did not show the same behavior before and after the action of alcohol. Bulk fill composite resins are extremely promising materials and are undergoing constant advances made by the industry to improve them and make their use reliable by professionals.