Compatibility With Gypsum and Dimension Change of Disinfected Impression Materials

Objectives: The aim of this study was to evaluate the linear dimension change after 10 minutes immersed in disinfectant (1% sodium hypochlorite or 2% glutaraldehyde solution) and gypsum compatibility of three vynilpolysiloxane (VPS) and three polydimethylsiloxane (PDS) low viscosity materials, respectively: Express (3M/ESPE) - EX; Aquasil (Dentsply) - AQ; and Adsil (Vigodent) – AD; Xantopren (Heraeus) – XA; Speedex (Vigodent) – SP; Oranwash (Zhermack) – OR. Methods: ISO 4823 international standard was used for such test comparison. VPSs and PDSs were extruded onto the stainless steel test block following manufacturer mixture instructions. After setting time, all specimens were removed from the test block and analyzed under a 10x magnification. Digitalized measurements of the distances between lines “d1” e “d2” along line “c” (n=5) were run before and after disinfection by a specific software (Caliper Imaging Software). A type IV dental stone was poured onto each specimen to evaluate the 50um line “a” complete reproduction. All measurements were submitted to ANOVA and Tukey test (p<0.05) for comparison. Results: In comparison with test block control, VPSs impression dimensions remained unchanged after glutaraldehyde disinfection (p>0.08), but Express was affected by hypochlorite (p<0.02). XA and SP showed no changes for d1-d2 measurements when hypochlorite was used (p>0.15), but OR dimension changed (p<0.04). All PDSs remained unchanged after glutaraldehyde immersion (p>0.20). All materials tested were effective on line “a” complete reproduction (p>0.05) Conclusions: VPS and PDS impression materials showed differences for linear dimensions measurements after disinfection, but compatibility with type IV dental stone were not affected after disinfection bath.