A good seal ability and antimicrobial action is a desired feature of an effective temporary sealing material. Aims: To compare the sealing ability and antimicrobial activity of three temporary sealing materials: Caviton, MD Temp and IRM Materials and Methods: In the present in vitro study, sealing ability (dye penetration method using 2% methylene blue) was measured with class I cavities on human premolars restored using test materials. The antimicrobial activity (agar diffusion test) of the materials was evaluated against Streptococcus mutans (MTCC 497 and clinical isolate) and Candida albicans (ATCC 60193 and clinical isolate). Statistical Analysis Used: For sealing ability, data was statistically analysed using Chi‑square test at a significance level of 5% using Statistical Package for Social Sciences (SPSS) 15.0. Antimicrobial activity was evaluated by comparing the mean diameter of the inhibition zones formed around the respective wells. Results: IRM produced best marginal sealing (Fisher’s exact test = 38.361 and P < 0.001) and was also associated with higher antimicrobial activity in comparison to Caviton and MD Temp. The inferior properties of MD temp can be attributed to thermal instability demonstrated by MD Temp leading to an inadequate seal, and also failed to produce a zone of inhibition. IRM proved effective and superior to Caviton and MD Temp in both these aspects. Conclusions: The success of an endodontic treatment depends on the effective seal achieved following debridement. This study stresses the need for an adequate marginal seal along with satisfactory antibacterial potential for a temporary sealing material.
