Items such as impressions, occlusal rims, dentures or bridge works could be contaminated with oral microflora or other organisms of varying pathogencity. Several approaches have been tried to control transmission of infectious organisms via dental impressions; because disinfection of impressions is less effective and has other drawbacks, several sterilization methods have been suggested. Objectives: This study aimed to evaluate the reproducibility of rubber impressions after sterilization by different methods. Methods: Dimensional accuracy and wettability of two rubber impression materials (vinyl polysiloxane and polyether) were evaluated after sterilization by each of three well-known methods (immersion in 2% glutaraldehyde for 10 hours, autoclaving and microwave energy). Non-sterilized impressions served as a control. The effect of the tray material on impression accuracy and the effect of topical surfactant on the wettability were also evaluated. Data analyses used one-way ANOVA with Dunnett's method. Results: All sterilizing methods reduced the reproducibility of rubber impressions, though not always significantly. Microwave sterilization had a small effect on both accuracy and wettability. The larger effects of other methods could usually be overcome by using ceramic trays and by spraying impression surfaces with surfactant before pouring the gypsum mix. There was one exception: gluteraldehyde still degraded dimensional accuracy even with ceramic trays and surfactant. Conclusions: Sterilization of rubber impressions made on acrylic trays is usually associated with a degree of dimensional change. Microwave energy seems to be a suitable technique for sterilizing rubber impressions. Topical surfactant application helps restore wettability of sterilized impressions. Supported by NIDCR P30-DE09737.

Back to the Dental Materials: VIII - Others-Non-metallic Program
Back to the IADR/AADR/CADR 80th General Session (March 6-9, 2002)

Top Level Search