Evaluation of Elastic Recovery of Elastomeric Impression Materials Subjected to Various Disinfection Methods: An In-vitro Study

Abstract

Introduction: Disinfection of impressions is essential to prevent cross-contamination from the operatory to the laboratory. Various methods have been employed to disinfect the impressions. These disinfection methods should not alter the physical and mechanical properties of impression materials. Aim: To evaluate the Elastic Recovery (ER) of elastomeric impression materials subjected to different disinfection methods. Materials and Methods: This was an in-vitro study conducted at KIMS Dental College and Hospital, Amalapuram, Andhra Pradesh, India and Vishnu Dental College, Bhimavaram, Andhra Pradesh, India over a period of 5 months from August 2022 to December 2022. A total of 120 impressions were made using three different types of elastomeric impression materials: Poly Vinyl Siloxane (PVS), Vinyl Poly Ether Siloxane (VPES), and Poly Ether (PE). A metal die was made as per American Society for Testing and Materials (ASTM) D412 and International Organisation for Standardisation (ISO) Specification 4823, containing a lower and upper member. These impressions were trimmed to the dimensions of a stainless steel stencil, measuring at points with uniform thickness. The impressions were then subjected to autoclave and chemical disinfection using 5% Glutaraldehyde (Korsolex) and Ethanol-2-Propanol (Bacillol). The samples prepared were fixed in the tensile grips of a Universal Testing Machine (UTM) and subjected to tensile loading at a crosshead speed of 10 mm/minute until tearing. The distance between the break ends was measured using a digital Vernier Callipers, and ER was measured. One-way Analysis of Variance (ANOVA) followed by Tukey’s post-hoc tests were used to analyse the obtained study data. Results: The PE impression material demonstrated more ER when subjected to different disinfection methods compared to the other materials. Significant differences were observed between the ER of impression materials with different disinfection methods (Autoclave: p<0.001, Korsolex: p<0.001, and Bacillol: p=0.007). Conclusion: For better ER, PVS can be sterilised with Bacillol and Korsolex. Korsolex should be avoided for disinfecting PE. VPES performed better with autoclave and Korsolex.

Keywords

• cross-contamination
• glutaraldehyde
• vinyl poly ether siloxane
• tear strength