Influence of mouthrinses on the hardness of composite resin materials

Abstract

The aim of this study was to examine the effect of three mouthrinses (Listerine™ [LIS], PerioGard™ [PER] and Cepacol™ [CEP]) on the microhardness of three different aesthetic restorative materials (Filtek Supreme™ – nanofilled [SUP], Filtek Z 250™ – hybrid [Z25] and Filtek Flow™ – hybrid of high viscosity [FLO]). Mouthrinses were used as treatment groups, while distilled water served as the control. Seventy two matrices of nylon polymer were manufactured with 3 mm diameter and 3 mm thickness. Each composite filled the matrices in two increments, which was separately light-cured for 20s. Specimens (cps) were planned with abrasive papers and stored in distilled water for 24 hours. Composite specimens were divided into four groups (n = 6) according to the solution to be studied; specimens were immersed in the mouthrinses for 10min, three times a day, during a 30 day period. During the period of the study, specimens were individually stored in distilled water. At the end of the test period, the Knoop hardness number (KHN) was measured. Five indentations were performed on the surface of each sample and a mean value was determined. Statistical analyses were performed by analysis of variance and Tukey- test. The results and standard deviations (SD) were: SUP + LIS = 63.3(5.2)Bb; SUP + PER = 70.0(3.6) Ab; SUP + CEP = 67.8(3.6)ABb; SUP + AD = 64.3(3.8)Bb; Z25 + LIS = (2.4)88.4Aa; Z25 + PER = 77.1(5.4)Ba; Z25 + CEP = 83.8(3.9)Aa; Z25 + AD = 83.7(4.1)Aa; FLO + LIS = 44.3(4.1)Ac; FLO + PER = 46.5(1.6)Ac; FLO + CEP = 48.7(2.0)Ac; FLO + AD = 44.2(0.8)Ac. There were statistical differences among the microhardness values of the three composite resins tested, Z25 > SUP > FLO. The performance of the composite resins varied according to the type of solution investigated.