The comparison of compressive strength and diametral tensile strength of dental casts made of type III dental stone after a sequence of disinfection for 7 times with 1% virkon and 0.525% hypochlorite solutions

Abstract

There is a close relationship between dental casts and impression materials as well as other items potentially contaminated by saliva and blood from the patients mouth. Consequently, dental casts are one of the important items causing crosscontaminatin. To interrupt the cross-contamination cycle, several methods have been applied so far, from which chemical disinfection procedures are more dominant and can be applied either by immersion or surface spray methods. Virkon is a unique powder product for the safe and rapid disinfection of surfaces and equipment in a wide variety of situations. It can be dissolved in water for use, providing a safe working solution with a faint lemon odour .The objective of the present study is the comparison of compressive strength and diametral tensile strength of dental casts made of type III dental stone after a sequence of disinfection for 7 times with 1% virkon and 0.525% hypochlorite solutions. Material and methods: 1%Virkon , 0.525% sodium hypo chlorite and slurry solutions were prepared. The solutions were sprayed seven times on casts prepared from stone type III. After 24 hours of the last spray, the samples were held under diametral tensional and pressure strength with Instron system. Results: The mean of pressure strength in three groups of sodium hypochlorite, virkon and slurry solutions were 11.03,14.26, 11.12 respectivly. The tensional strength in sodium hypochlorite , virkon and slurry solutions were 1.44, 1.81 and 1.51, respectively. Conclusion : According to mean of tensional and pressure strength and p<0/05 , there is no meaningful difference observed in this case and both materials can be used.