Comparative Evaluation of the Properties of Irreversible Hydrocolloid Materials Following the Addition of Two Different Local Anesthetic Agents: An In Vitro Study.

AIM: This study aims to evaluate the impact of incorporating irreversible hydrocolloid impression materials with local anesthetic agents, specifically 2% lignocaine and 0.5% bupivacaine, on their compressive strength, tear strength, and molecular properties, which can determine their efficacy in managing the gag reflex during impression-making without compromising material performance. MATERIALS AND METHODS: This study evaluated the effects of lignocaine and bupivacaine on the compressive and tear strength of alginate materials. A total of 120 samples were divided into control and experimental groups using Tropicalgin and Algitex, with experimental groups incorporating 2% lignocaine or 0.5% bupivacaine. Strength tests were conducted using standard molds and a universal testing machine. Compressive strength was tested at 50 mm/min under 100 N, and tear strength as load per thickness at 500 mm/min. Results highlight the impact of anesthetic additives on alginate properties. RESULTS: This study showed no statistically significant difference in compressive strength between the control and study groups and a negligible difference in tear strength. A Fourier transform infrared spectroscopy analysis showed optimal molecular affinity between irreversible hydrocolloids and local anesthetic agents (2% lignocaine and 0.5% bupivacaine) across all samples, both before and after setting. CONCLUSIONS: This in vitro study, within its limitations, found that adding local anesthetic agents to irreversible hydrocolloid impression materials may reduce the gag reflex without affecting their compressive strength, tear strength, or chemical properties.