Effect of contemporary retraction agents and cleaning with hydrogen peroxide on the polymerization of elastomeric impression materials

Abstract

The aim of the study is to investigate the polymerization inhibition of elastomeric impression materials vinylpoly siloxane (VPS) and polyether (PE) when used in combination with retraction materials with and without subsequent cleaning with hydrogen peroxide (H2O2). Methods: Seven stainless steel specimens were fabricated. Four hundred and twenty impressions were made with three different elastomeric materials (140 each) as follows: group 1: VPS-Panasil; group 2: VPS-Express; group 3: PE-Monophase. Each material group was further subdivided into seven subgroups, based on use of no retraction material (control), three different retraction materials [Retraction capsule (RC3M), Dryz, Expasyl], and two cleaning techniques (water and H2O2). All subgroups included 20 impressions, which were made by a single operator using an automix gun. Evaluations were made using a visual scale by three calibrated examiners blindly and independently. Subjective categorization of the impressions were made as inhibited and uninhibited. Data were analyzed using Fisher’s exact test and significance was set at p < 0.05. Results: Inhibited impressions were lower than uninhibited impressions among VPS materials (Panasil and Express); Panasil and Express showed comparable ( p > 0.05) impression retardation. PE showed significantly higher inhibition compared to VPS materials ( p < 0.05). Expasyl showed significantly higher polymerization inhibition than other retraction materials ( p < 0.05). The use of H2O2 for cleaning showed significant reduction in polymerization inhibition than cleaning with water for Expasyl ( p < 0.05). Conclusion: Overall contemporary retraction materials showed low potential for polymerization inhibition of elastomeric impression materials. Expasyl should be cleaned with H2O2 prior to impression making. However, Dryz and RC3M can show accurate impressions with water cleaning alone.

Effect of Gingival Hemostatic Agents on the Surface Detail Reproduction and Dimension Stability of Three Elastomeric Impression Materials

“…Expasyl was reported to have a higher inhibition ability than other astringent materials. Moreover, Expasyl provided a higher polymerization rate after cleaning with hydrogen peroxide [ 12 , 13 ].…”

“…The studies have reported polymerization inhibition, which results in poor surface detail reproduction. However, Vohra et al [ 12 ] in 2020 reported only 20% surface detail reproduction from monopolyether impression material when contaminated with DryZ. The result could be affected by the product itself.…”

Management of Edentulous Microstomia Patient: A Case Report and Classification System

“…The impression compound used for primary impression also acts as a flexible impression tray, in case the impression requires retake and improvements. The PVS medium body final impression was made for increased accuracy, dimensional stability, and elastic recovery [16].…”