Disinfection of dental gypsum model with 0.5% sodium hypochlorite: Effect on dimensional stability

Objective: To evaluate and compare the effect different techniques of disinfection of irreversible hydrocolloid and type III dental gypsum, with 0.5% NaOCl, on their (linear) dimensional stability. Study design: Quasi Experimental study. Setting: Department of Metallurgy, Pakistan Council for Scientific and Industrial Research (PCSIR) Lahore. Duration with dates: Six months, from June 1, 2006 to November 30, 2006. Subjects and methods: Ninety (90) casts were made from Irreversible Hydrocolloid Impression by non-probability purposive sampling technique. Measurements of the casts at three specific points were carried out using measurement guiding template through screw gauge and were recorded. Results: In this study Sodium Hypochloride 0.5% was used as disinfectant material for type III dental gypsum. Disinfection of type III dental gypsum, by Sodium Hypochloride 0.5% had no negative effect on their linear dimensional stability. Conclusion: Disinfection of Dental Gypsum type-III either by immersion and incorporation is easy and dimensionally stable.