ABSTRACT
The objective of this study was to evaluate the effect of storage in deionized water at room temperature, for seven days and six months, on the flexural strength of a repaired photocured microhybrid composite resin, using different surface treatments. After each surface treatment, the adhesive interface was analyzed with a surface roughness tester. The flexural strength of samples from each group was determined by three-point bending in a testing machine at a crosshead speed of 0.5 mm/min with a 50 N load cell. Data were analyzed using ANOVA (p=0.0001) and compared with the Newman-Keuls multiple comparison test. It was verified that flexural strength of the unrepaired specimens, after both seven days and six months, was similar (p>0.05) and was in accordance with ISO specifications (minimum of 50 MPa), with values ranging from 52-63 MPa. The authors concluded that the use of an unfilled resin agent is necessary prior to the repair to increase the adhesive strength. Further, the use of a silane agent prior to use of the unfilled resin agent is unnecessary, since it does not increase the adhesive strength.
