Effect of Autoclave Sterilisation on the Dimensional Stability and Tear Strength of Three Silicone Impression Materials

Brian J Millar,Sanjukta Deb

doi:10.4236/ojst.2014.412069

Abstract

Objectives: There is a risk of spreading infectious material via non-sterile impressions. The aim of this study was to compare the effect of autoclave sterilisation on dimensional stability and tear strength of impression materials. Methods: Twenty-four specimens were produced using a standard ruled test block for each of three impression materials (Affinis, Aquasil and Speedex) to test dimensional stability. Thirty tear strips for each material were prepared for the tear test (ISO 34-1). Specimens were randomly allocated to 3 different groups (autoclaved, disinfected or untreated). A non-contact scanner was used to analyse dimensional change and a universal testing machine was used to determine tear strengths. Results: There were no significant differences in the test dimensions measured for any of the three impression materials following autoclave treatment compared to the disinfected or untreated control groups. The tear strengths were not adversely affected by autoclave sterilisation at 134°C. Conclusion: These addition and condensation-cured silicone impression materials can be steam autoclaved without adverse effects on dimensional accuracy or tear strength.

Highlights

There is an increased awareness of the risks through cross-infection within dental practice and autoclave sterilisation is the preferred option to deal with non-disposable items, which have come into contact with the oral tis
The results of this study showed that there were significant structural changes (>0.5% change) occurring post-autoclaving suggesting that this is due to the distortion of the trays themselves or their incapability to prevent expansion of the impression material
A comparison of the mean values for each of the three test impression materials showed that there was no significant difference between the autoclaved, disinfected and control specimens in each case

Summary

Introduction

There is an increased awareness of the risks through cross-infection within dental practice and autoclave sterilisation is the preferred option to deal with non-disposable items, which have come into contact with the oral tis-How to cite this paper: Millar, B.J. and Deb, S. (2014) Effect of Autoclave Sterilisation on the Dimensional Stability and Tear Strength of Three Silicone Impression Materials. There is an increased awareness of the risks through cross-infection within dental practice and autoclave sterilisation is the preferred option to deal with non-disposable items, which have come into contact with the oral tis-. How to cite this paper: Millar, B.J. and Deb, S. (2014) Effect of Autoclave Sterilisation on the Dimensional Stability and Tear Strength of Three Silicone Impression Materials. The current standard for dental impressions after removal from the mouth is disinfection despite studies [1] [2] showing disinfection does not remove potential contaminants. The important potential route of transmission of infective material from a patient to the dental laboratory and beyond via an impression is best dealt with by sterilisation of the impression at source soon after removal from the oral cavity

Objectives

Methods

Results

Conclusion