The effect of water and sodium hypochlorite disinfection on alginate impressions

AbstractIntroductionThe control of cross-infection is an imperative issue when dealing with dental impression materials in Dentistry and the lack of procedures for its control is currently a real problem. The aims of the present study consisted in evaluating the effectiveness of water washing and sodium hypochlorite disinfection in reducing the microbial load of alginate after mouth contact.Materials and methodsThirteen students voluntarily participated in the present study. The inclusion criteria were age between 21 and 24 years, inexistence of smoking habits and systemic and salivary gland pathologies, DMFT index (decay/missing/filled teeth)≤5 and tooth brushing with right hand. For each participant, one impression was taken in alginate from the mandibular arch. These samples were submitted to water wash and sodium hypochlorite disinfection and to subsequent microbiological analysis. Statistical analysis included the analysis of variance for multiple comparisons (one-way ANOVA) followed by Student's t-test.ResultsAfter mouth contact, alginate microbial count increased from 1.59±2.79 to 2.68×103±6.19×102CFU/mm2. It was verified that after water wash the microbial count decreased to 48.5% while after sodium hypochlorite disinfection microbial count decreased to 99.99%.ConclusionDental impression materials can act as vectors transmitting a significant amount of microorganisms. Sodium hypochlorite disinfection is an efficient disinfection method for alginate impressions. Tap water rinsing reduces microbial load but does not eliminate the cross-infection potential of alginate