Dimensional stability of vinylsiloxanether impression material after autoclave sterilization - an in vitro study

ABSTRACT

Dental impressions are often neglected in clinical practice as a source of spread of infectious diseases. In Pakistan more than fifty percent of the clinicians do not disinfect impressions. Blood and saliva contaminated impressions should be either disinfected or sterilized before further handling. Aim of this study was to determine effect of autoclave sterilization on the time dependent dimensional stability of vinylsiloxanether impression material. Impressions of stainless steel die [ADA/ANSI specification No. 19], were made of Vinylsiloxanether. Out of 40 specimens, half were allotted to group A and were autoclaved at 134°C AND 20 psi for 5 minutes. Rest of the specimens [Group B] served as a control. Dimensional changes were calculated for two time intervals i.e. after one hour and after twenty-four hours. Samples were scanned and images were analyzed by using Adobe reader XI [AcroRd 32] software. Paired t-test showed significant difference [p = 0.007] between readings at first hour [-0.047%] and twenty fourth hour [0.084%] in group A. Whereas independent t-test showed no significant difference in group A and B for both time intervals i.e. at first hour [p = 0.162] and twenty fourth hour [p = 0.148]. It was concluded that Vinylsiloxanether can be sterilized in an autoclave without any deleterious change in dimensions