Influence of different methods of chemical disinfection on the physical properties of dies made of gypsum type IV and V

Abstract

Several instruments and materials frequently used in prosthodontics - such as stone casts, dental impressions, interocclusal records - are classified, by the dental literature, as vehicles of transmission of infectious diseases to those who handle them. The present study aims at comparing dimensional alteration, superficial texture and compression resistance of stone dies submitted to different disinfection methods: 30-minute immersion in 1% sodium hypochlorite or in 2.2% alkaline glutaraldehyde (with or without previous ultrasonic washing) and addition of 2.2% alkaline glutaraldehyde or 5% sodium hypochlorite to the gypsum during its preparation. It was possible to conclude that: (1) chemical disinfection did not cause significant dimensional alteration in stone dies; (2) superficial texture was altered according to the disinfection method utilized; (3) immersion in disinfectant solution during 30 min, as well as the addition of disinfectant to the gypsum during its preparation, reduced the compression resistance of dies.