Microorganism count on irreversible hydrocolloid impressions with sodium hypochlorite disinfectant

“Objectives:” The aim of this study was to count the microorganisms found in irreversible hydrocolloid impression material after their submersion in different dilutions of sodium hypochlorite. The oral environment harbors a large number of microorganisms in the saliva that may contain infectious microbes. Sodium hypochlorite solution may reduce the microorganisms count on impressions.

“Methods:” A total of 46 patients lower impressions were selected randomly from prosthodontic clinics at King Abdulaziz University. These comprised a random sample of 23 male and 23 female lower arch irreversible hydrocolloid impressions. Impressions were submersed in sterilized plastic containers with 100 ml sterile distilled water. Serial concentrations of sodium hypochlorite solutions: 3, 5, 7, 10, and 15% were used as a disinfectant with a submersion time of 1 minute. The mean total microorganism count was determined using a plate counts. The data were analyzed with 1-way ANOVA and post hoc Tukey HSD test (á=.05).

“Results:” Bacterial counts were significantly different for sodium hypochlorite concentrations and gender of subjects (P<.001). The highest mean bacterial count (972.4 ± 4924.1) X103.mL -1 was for male patients. The lowest mean bacterial count (1.4 ± 7.6) X103.mL -1 was for female patients. Fungal counts were only significantly different for sodium hypochlorite concentrations (P<.001) and not for gender. The greatest fungal count (1.449 ± 0.1) X103.mL -1 was for male patients. The lowest fungal count (0.4 ± 2.6) X103 mL -1 was for female patients.

“Conclusion:” Sodium Hypochlorite at 3% concentration has been shown to be an effective disinfectant to eliminate bacteria and fungi efficiently from irreversible hydrocolloid impression surfaces.