Comparison of the dimensional stability of alginate impressions disinfected with 1% sodium hypochlorite using the spray or immersion method
Objective: To determine and compare the dimensional stability of alginate impressions disinfected with Sodium hypochlorite using the spray and immersion methods. Methodology: Alginate impressions of a master model of truncated metal cones were made and disinfected with 1% sodium hypochlorite constituted from 3.5% household bleach using the spray and immersion technique for 10;20 and 30 minutes. Impressions were cast in dental stone and the linear dimensional differences between the inter-abutment distances were measured with an electronic caliper. One sample T test and percentage differences were calculated. Result: There were no statistically significant differences in dimensions of alginate impressions of the control and those disinfected by either spraying or immersion methods when compared with the master model at 10 minutes. However, there was a statistically significant difference at 20 and 30 minutes. The spray technique showed the least percentage difference from the master model. Conclusion: Disinfection of alginate impressions with 1% sodium hypochlorite constituted from commercially available household bleach by the spray or immersion techniques for ten minutes will produce casts with minimal dimensional changes.