LAUSR

AIM The present study was intended to evaluate the antimicrobial effect of PDT, H2O2, and MI on the contact angle, strain-in-compression, and tear strength of siloxane impression material formerly colonized with E. coli, S.aureus and S.mutans. MATERIAL AND METHODS One hundred and twenty disc-shaped specimens (diameter 10 mm and thickness 2 mm) were prepared by polyvinylsiloxane impression material and inoculated by the American Type Culture Collection (ATCC) of E.coli, S.mutans, and S.aureus in an in-vitro situation. The specimens were broadly divided into six groups then exposed to the various disinfection approaches for 3 mins per each group: group 1: Control (no treatment), group 2:PDT 5-ALA, group 3: H2O2, group 4: MI, group 5: H2O2 + MI, group 6: PDT + MI. After disinfection, assessment of mechanical properties (contact angle, strain-in-compression, and tear strength) of impression materials were instigated. Statistical analysis was executed for CFU/mL (log10) for exposed E. coli, S.aureus, and S.mutans, by two-way ANOVA and Tukey's honestly significant test (p>0.05). RESULTS The highest anti-microbial values against all inspected microbial colonies were unveiled when disinfection was performed in combination i.e., H2O2 + MI and PDT + MI and the least cleansing of impression material was seen by the control group as no treatment was provided. Solo application of MI was more effective than control, H2O2 and 5-ALA activated by PDT but less active when used in combination method H2O2 with MI and PDT with MI. PDT and control group showed the least antimicrobial effectiveness against E. coli (p<0.05) CONCLUSION: : Disinfection of impression materials with combination therapies including photodynamic therapy with microwave irradiation and hydrogen peroxide with microwave irradiation displayed highest antimicrobial efficacies against E. coli, S. aureus, and S. mutans with no adverse effects on mechanical properties of impression material.