Evaluation of antimicrobial property of zinc acetate and its effect on flexural strength of denture base resin- An in vitro study

Purpose: The intaglio surface of complete denture is not polished so due to rough surface adhesion of microorganisms to denture surface. This study aimed to measure the antimicrobial activity and flexural strength of heat cure acrylic resin after incorporating zinc acetate in different percentage. Materials and Method: A total number of thirty-two disk shaped (6mm x 1mm) and rectangular shaped samples (65mm x 10mm x 2.5mm) were prepared from heat-polymerized acrylic resin incorporated with Zinc acetate. The zone of inhibition diameters were measured with zone measuring scale (in mm) and this measurement indicated the microbial susceptibility to the material. And, the flexural strength of the specimens was determined using a 3-point bend testing device in a Lloyd's Universal Testing Machine. The measured values were submitted to statistical analysis by descriptive statistics, independent sample't' test and one way ANOVA followed by Scheffe's Post Hoc test. Results: One way ANOVA descriptive analysis detected the different percentage of zinc acetate in heat polymerized acrylic resin showed significant difference. The increasing order of antimicrobial activity is: Group A (control) < Group B (2.25% zinc acetate) < Group C (5% zinc acetate) < Group D (7.25% zinc acetate). However, the increasing order of flexural strength is: Group D (7.25% zinc acetate) < Group C (5% zinc acetate) < Group B (2.25% zinc acetate) < Group A (control).