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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Oderinu
O H
OH
Department of Restorative Dentistry, School of Dental Sciences, College of Medicine, University of Lagos, Lagos, Nigeria.
Adegbulugbe
I C
IC
Shaba
O P
OP
D000464:Alginates / Q000737:chemistry*; D003760:Dental Impression Materials / Q000737:chemistry*; D004202:Disinfectants / Q000737:chemistry; D004203:Disinfection / Q000379:methods*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D008422:Materials Testing / Q000379:methods; D012973:Sodium Hypochlorite / Q000737:chemistry*
D000464:Alginates; D003760:Dental Impression Materials; D004202:Disinfectants; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D012973:Sodium Hypochlorite