Effect of disinfectants on the dimensional stability of dental impression materials - an In Vitro study

Objectives: Infections occurring in health care settings have become well-recognized problem leading to an increasing public awareness. During prosthodontic dental treatment, impressions of prepared teeth are transferred to different dental laboratories increasing the risk of infection spreading. Though guidelines related to disinfection of dental impressions exist, few dentists implement them. This is due to various reasons, one of which is the clinicians' fear of dimensional distortion, which may cause prosthetic inaccuracy.
The aim of this study was to examine the changes in accuracy and dimensional stability of three disinfectants on three different impression materials.


Methods: Using a model with two standardized metal cubes, three common impression materials (Alginate, Polyether and P.V.S) were used to create a standard impression model which was then washed under running water for 15 seconds and then soaked for 10 minutes in one of the three disinfectant solutions (Chlorine, Polydine and OPA), and water as negative control. Measurements of depth and horizontal distances between reference points were performed before and after the process using a caliper. Additional measurements were done using a radiographic cone-beam CT scan, using ICATVision software. Measurements were averaged separately for each impression material, comparing each disinfectant solution with water, and also before and after for the same disinfectant.
Results: For all disinfectants, there were no significant differences between the measurements values before and after disinfection procedures, nor for differences between each one compared with control
Conclusions: The results suggest that the disinfection process using the three tested disinfectants does not significantly affect the dimensional stability of the tested impression materials, and their effect on the prosthetics accuracy is negligible. Therefore, we encourage practitioners to disinfect impression without any fear of distortion, before their transfer them to the dental laboratory.