Assessment of Effect of Different Sterilization Agents on Dimensional Accuracy of Different Impression Materials in Implant Prosthesis - An In vitro Study.

AIM: Sterilization of impression materials is of paramount importance. The present study was conducted to compare the effect of different disinfectants on dimensional accuracy of elastomeric impression materials used for implant prosthesis and other routine treatments. MATERIALS AND METHODS: The present study was conducted with polyvinyl siloxane (PVS) (regular body), PVS (medium body), PVS (heavy body), and polyether (medium body) impression materials. Glutaraldehyde (2%) and sodium hypochlorite (NaOCl, 0.525%) were the disinfectant solutions employed in the study. After 16 h, the specimens were measured under Leica WILD stereomicroscope and dimensions were compared with master die. RESULTS: The dimensional change in the Controls, 2% glutaraldehyde (Group I), and 0.525% NaOCl (Group II) was non significant where as Group III and Group IV showed statistically significant difference (P < 0.05). Results also showed significantly higher tear strength (newton/millimeter) in Control group followed by Group I and Group II. CONCLUSION: PVS (heavy body) was found to be most stable, and polyether was seen to be stable of all the impression materials.

Assessment of Aluminum Chloride Retraction Cords, Expasyl, and Tetrahydrozoline-Soaked Retraction Systems in Gingival Retraction.

AIM: The aim of this study was to assess different gingival displacement systems such as aluminum chloride retraction cords, expasyl, and tetrahydrozoline-soaked retraction cord to record intracrevicular margins of tooth preparations. MATERIALS AND METHODS: This study included 60 patients. Patients were divided into four groups of 15 each. In group I, aluminum chloride retraction cords, in group II expasyl, in group III tetrahydrozoline-soaked retraction cord, and in group IV no retraction cord were used. RESULTS: The mean gingival displacement (µm) in group I was 825.6, in group II was 482.1, in group III was 742.3, and in group IV was 214.8. Significant difference was seen in between groups by one-way analysis of variance as P < 0.05. Post hoc Tukey analysis showed significant difference during multiple comparison between groups. CONCLUSION: Authors found that maximum gingival retraction was achieved with aluminum chloride retraction cords followed by tetrahydrozoline and expasyl.