Dimensional Stability of Elastomeric Impression Material After Disinfection Via Immersion and Microwave Irradiation

Noorhayati R Mohd,Enas A Etajuri,Ros A Omar

doi:10.2174/1874210602115010658

Abstract

Aims: This study aimed to evaluate and compare the dimensional stability of two elastomeric impression materials, namely polyvinyl siloxane (PVS) and vinyl siloxanether (VSE), subjected to chemical immersion and microwave irradiation for disinfection. Materials and Methods: Sixty discs of PVS and VSE impression materials each were prepared using a stainless-steel test die and ring in accordance with ANSI/ADA Specification No. 19. Twenty discs of each impression material were disinfected by chemical immersion for 10 min; another 20 discs were subjected to dry microwave irradiation for 3 min. The other 20 discs served as a control group. Dimensional stability measurements were then performed using an image analyzer at 20× magnification. The data were analyzed by one-way analysis of variance (α=0.05) and Bonferroni (post hoc) test for multiple comparisons to detect significant differences between the groups. Results: When subjected to microwave irradiation, both PVS and VSE showed dimensional changes, but the changes were within the limit of 1.5% set by ANSI/ADA (P<0.00). VSE showed markedly better results than PVS for both disinfection methods. The immersion disinfection method resulted in a higher average percentage of linear dimensional changes than both the microwave irradiation and the control for VSE and PVS impression materials. Conclusion: VSE exhibited excellent dimensional stability than PVS under both chemical immersion and microwave irradiation. Microwave irradiation using conventional microwave ovens can be used in clinical settings as an alternative to other disinfection techniques because the dimensional changes of the elastomeric impression materials subjected to microwave irradiation have been observed to be within the clinically acceptable limit set by the ANSI/ADA standard.

Highlights

Impression making is a routine procedure in dental clinics [1]
The American Dental Association (ADA) recommends dental clinics and laboratories to follow appropriate disinfection protocols established by the Center for Disease Control (CDC) to prevent cross-infection between patients, dentists, and dental technicians [4, 5]
In a continuing effort to better understand the accuracy and dimensional stability of elastomeric impression materials, this study investigated the effect of disinfection using chemical immersion and microwave irradiation on the linear dimensional changes of polyvinyl siloxane (PVS) and vinyl siloxanether (VSE) impression materials

Summary

Introduction

Impression making is a routine procedure in dental clinics [1]. To minimize the occurrence of contaminants, impressions should be rinsed under running tap water immediately after removal from a patient's mouth. Rinsing with water significantly reduces the microbial count on the impression surface, it does not reduce the infection poten-. The American Dental Association (ADA) recommends dental clinics and laboratories to follow appropriate disinfection protocols established by the Center for Disease Control (CDC) to prevent cross-infection between patients, dentists, and dental technicians [4, 5]. Several disinfection methods are used to disinfect different impression materials. The most common method is chemical disinfection, wherein the impression surface is treated chemically, either by immersion or spraying.

Methods

Results

Discussion

Conclusion