In vitro evaluation of the effect of three mouthwashes on microhardness of a composite resin

ABSTRACT

Regular application of mouthwashes has been recommended for the prevention and control of caries and periodontal diseases. Use of mouthwashes can affect restorative dental materials. The purpose of this in vitro study was to investigate the effect of three commercially available mouthwashes [Irsha, Chlorhexidine, Oral-B] in Iran on the microhardness of Z100 composite resin. In this in vitro experimental study 30 cylinders of composite resin were fabricated and stored in distilled water for 24 hours. Vickers hardness [VH] values of the samples were measured using Vickers hardness tester. The samples were stored in the mouthwashes for 12 hours, which was equivalent to two minutes of daily mouthwash application for a year. Microhardness values were measured again after immersion in the mouthwashes. Data was analyzed with ANOVA and Tukey test [alpha = 0.05]. Means of microhardness values for composite resin samples stored in Irsha, chlorhexidine and Oral-B mouthwashes were -1.94 +/- 0.23, -16.14 +/- 0.7 and -7.37 +/- 1.4, respectively. Differences in microhardness values in the Irsha group were higher than the two other groups, with statistically significant differences [p value < 0.05]. Under the limits of the present study it was concluded that various mouthwashes do not exert the same influences on the microhardness of composite resins. Chlorhexidine exerted the least influence on microhardness among the three mouthwashes under study