Comparative Evaluation of Disinfecting Alginate Using Aloe Vera and 0.2% Chlorhexidine Digluconate by Internal Disinfection Method - An In Vivo Study

BACKGROUND Aloe vera and chlorhexidine are traditionally used as disinfectants of irreversible hydrocolloids. Most popular among irreversible hydrocolloids is alginate which is most commonly used in dentistry. We wanted to compare and evaluate the efficacy of aloe vera and 0.2% chlorhexidine as an internal disinfectant. METHODS For each subject three impressions of the upper arch were made using irreversible hydrocolloid impression material i.e. Alginate (Zelgan 2002). After the impression was made, a sterile cotton swab was used and wiped over the impression surface from the center of the palate and was sent for culture sensitivity test. This swab acted as the control group (Group 1). The swab was then placed in normal saline transport medium and was sent for culture sensitivity test to the Gyan Pathology Lab, Kanpur. The swab was then run over the Blood Agar culture media. Incubation of the culture medium plates was done at 37 degrees C for 24 hrs. From the culture plate, smear was taken to examine bacterial growth on a slide, semi-quantitatively, under light microscope, and the colony forming units were then counted. 24 hours after initial impression, second impression (Group 2) was made by mixing alginate with 99.9% aloe vera. 48 hours after the first impression, the third impression (Group 3) of the same subject was made after mixing alginate with 0.2% chlorhexidine digluconate. Remaining procedural steps were similar for second and third impressions as the first impression. Bacterial count was recorded and analysed for variation between group 1, group 2 and group 3 using Repeated Measures ANOVA with post-hoc Bonferroni test from SPSS version 18. RESULTS This study showed that using 99.9% concentration of Aloe Vera as an internal disinfectant to manipulate irreversible hydrocolloid impression material did show a reduction (65.96%) in growth of aerobic bacteria. However, the decrease was significantly less when compared with chlorhexidine. CONCLUSIONS Amongst the two disinfecting agents used in this study, 0.2% chlorhexidine digluconate has shown to be more effective disinfecting agent than Aloe Vera.