Disinfection Of Dental Impressions: a Safe But Feared Step

Introduction: The control of cross infection during dental practice is a subject that requires awareness and attention. A disinfectant for dental impression materials must preserve the dimensional stability and the surface details of both the impression and the resulting cast, to achieve a more precise clinical outcome. Objectives: The purpose of this study to evaluate the knowledge regarding disinfection procedures among prosthesis technicians and dentists, as well as to assess the impact of water wash and of four disinfection solutions on the dimensional stability of addition silicone and alginate impressions. Materials and Methods: A survey was sent to 1000 dentists and 320 prosthesis technicians to evaluate their awareness and practices of dental impressions disinfection - response rate of 9.5% and 7.8%, respectively. The dimensional stability was evaluated using a standardized model, according to ANSI/ADA n°18 and 19 specifications. Ten impressions were taken for each of the established protocols: unwashed control, water washing for 30 seconds, immersion for 10 minutes in 3% hydrogen peroxide, 1% and 5.25% sodium hypochlorite and 5 minutes in MD520®. Results: 21.3% of the dentists never disinfect dental impressions, being one of the most common reasons the fear of dimensional changes (25%). Addition silicone and alginate impressions disinfection by immersion does not significantly impact the dimensional stability of the impressions (p>0.05). Conclusion: In this study, no detrimental effects were observed regarding the dimensional stability of disinfected dental impressions. It is fundamental to reinforce that disinfection procedures are safe and crucial to prevent cross contamination. Keywords: silicone elastomers, colloids, disinfection, sodium hypochlorite, hydrogen peroxide, survey