@Article{, title={The Effect of Microwave Disinfection on Tensile Strength of Dental Gypsum}, author={Radhwan H Hasan}, journal={Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان}, volume={8}, number={2}, pages={213-218}, year={2008}, abstract={Aims: To evaluate the effect of microwave disinfection on diametral tensile strength (DTS) of type IIIand type IV dental stones. Materials and Methods: A total of 80 cylindrical specimens was preparedwith dimensions 40 mm in height and 20 mm in diameter. These specimens were divided into 4 maingroups: Geastone type III, Zeta type III, Micromod type IV and Silky Rock type IV. Twenty specimensfor each main group were divided into 10 specimens as control subgroup and 10 specimens representingmicrowave irradiated subgroup. The microwave irradiation was performed in a household microwaveoven at 900 watts for 5 minutes. The DTS was conducted on a mechanical testing machine at across head speed of 1.0 mm/minute. The data were statistically analyzed using Student's t–test, analysisof variance and Duncan's Multiple Range test. Results: The microwave disinfection caused significantincrease in DTS (p < 0.05) for all types of dental stone, and dental stones type IV (Micromod and SilkyRock) had significantly higher DTS (p < 0.05) than dental stones type III (Geastone and Zeta). Conclusion:Microwave disinfection of gypsum cast cause significantly increase in diametral tensile strengthof type III and type IV dental stone.

} }