Evaluation of antimicrobial property of modified acrylic resin–containing cetylpyridinium chloride

OBJECTIVE: To evaluate the antimicrobial property of cetylpyridinium chloride (CPC) when polymerized with cold cure acrylic and to assess the duration of its release from modified acrylic. MATERIALS AND METHODS: CPC was added in different concentrations (0%, 2.5%, 5%, and 10%) to cold cure acrylic resin and 180 acrylic discs were prepared. These were divided into four groups of 45 each depending on the concentration of CPC. The antimicrobial property of the modified acrylic for Streptococcus mutans was tested using disc diffusion assay in agar. The duration of release of CPC from self-cure acrylic was tested with optical density reading of solutions by ultraviolet spectrophotometer. The effect of addition of CPC on diametral tensile strength (DTS) of acrylic was tested using UTM (Instron) and the effect of water aging on modified acrylic was compared with unaged specimens. RESULTS AND CONCLUSION: The normality of the data was checked by Shapiro-Wilktest, and as the data failed to show normal distribution, inferential statistics were performed using nonparametric tests of significance. Antimicrobial activity of modified acrylic increased with increase in CPC concentration. Greatest CPC release was observed on the seventh day with a decrease in release from 7 to 180 days. There was a decrease in the diametral strength of the modified resin and water aging had a significant effect on the DTS of the modified resin.