Study On The Influence Of Disinfection Methods On The Properties Of Stone Models And The Disinfection Effect

Objective: Stone models are materials commonly used in prosthodontitics, whose surface are contaminated by a substantial number of pathogenic micro-organisms. Without being treated with specialized disinfection, they would infect every dentist and dental technician who handle them, resulting in nosocomial cross-infection. The main aim of this article is to study the alteration of dimension, compression resistance and bending resistance of three kinds of stone models( plaster, artificial stone and superhard stone) submitted to various disinfection methods and the effect of disinfection methods,in order to find one method which not only unaffect the physical properties of stone model but also result in dependable disinfection effect.Methods: The three kinds of stone models are made of plaster, artificial stone and superhard stone according to the ratio of water to powder respectively, whose diameters are all 13 mm. There are 216 models in bending resistance test( plaster 72, artificial stone 72 and superhard stone 72),whose heights are all 40mm. There are 216 models in compression resistance test( plaster 72, artificial stone 72 and superhard stone 72),whose heights are all 20mm. There are 180 models in disinfection effect test( plaster 60, artificial stone 60 and superhard stone 60),whose height are all 10mm. Each kind of models in bending resistance and compression resistance test are divided into 6 groups, in which there are 12 models. The model of each group is treated with 75% alcohol spraying, 40% formaldehyde fumigation, UV exposure,the steam pressure sterilization, oxirane...