A comparative study on efficacy of various disinfectant systems on dental impression surfaces: In vivo study

Purpose: To evaluate the microbial load on impressions and the efficacy of various disinfectants on reducing microorganisms from the impression surface after disinfection. Materials and Methods: A total of 50 dentulous impressions were made for dentate patients each of age 20 to 50 years using Alginate and Polyvinyl siloxane. Impression compound and zinc oxide eugenol were used for edentulous patients each of age 50 to 70 years, total of 50 edentulous impressions were made. Samples were collected with the help of an 8mm diameter sterile cork borer from each individual impression. Alginate, ZOE and impression compound had 100 samples each. Polyvinyl siloxane had 125 samples. Out of 100 samples the first group of the sample was assigned as control (n=25), the second group of samples (n=25) were immersed in 2% Glutaraldehyde, the third group of samples (n=25) were sprayed with Dimenol, the fourth group of samples (n=25) were placed in the ultraviolet light chamber. For polyvinyl siloxane, an additional fifth sample group (n=25) was subjected to microwave radiation of 650W. The viability of microorganisms that can persist after rinsing and disinfecting the impression surface was tested by inoculating in nutrient media. The colony forming units were counted and compared with the control group. The data were documented and statistically analyzed. Results: There was a significant difference in the count among the control group and the disinfectant groups. Microbial load found on control groups was taken as 100%. Alginate samples which were disinfected with 2% Glutaraldehyde, Dimenol spray and UV light showed microbial load 31%, 46%, 44% respectively, Polyvinylsiloxane samples showed microbial load 35%, 53%, 48% and 0% with microwave radiation respectively. Impression compound samples showed 32%, 49%, 49% respectively & Zinc oxide eugenol samples with 2% Gluteraldehyde, dimenol and UV showed a load of 39%, 51%, 51% respectively. Conclusion: 2% Glutaraldehyde showed higher efficacy in reducing the microflora compared to Dimenol spray and UV radiation. There was complete removal of microorganisms with Microwave radiation.