Year : 2017

Volume : Volume 7

Issue : Issue 3

Address for correspondence :
Amit K Joshi
amitkjoshi@gmail.com

Abstract

Aim:  The purpose of the study is to compare dimensional accuracy and surface details under dry and moist condition of polyvinylsiloxane impression material. Materials and Methods: The study samples were assigned two groups based on the condition in which they were made. Group A consisted of casts obtained from impressions made in moist salivary condition (n=12). Group B consisted of casts obtained from impressions made in dry condition (n=12). Impressions of master model were made by using hydrophilic vinyl polysiloxane by two step putty-wash technique and working casts were obtained. Dimensional accuracy was measured by comparing the inter-abutment distance in each cast to the master model, by using a profile projector with an accuracy of 0.001mm. Surface detail reproduction was evaluated by use of criteria, continuous replication of at least 2 of the 3 horizontal lines. Statistical analysis was done and results were obtained.  Results: The inter-abutment distance was significantly increased compared to the master model in both the groups (P<0.05). The moist condition significantly affected the dimensional change of 0.6%. The dry and moist conditions had a significant effect on the detail reproduction of the material (P<0.05). Under dry condition the impression material satisfactorily replicated the details 100% of the time. Under moist condition, 58% of the impressions were judged satisfactory.   Conclusion: Presence of moisture caused a significant adverse effect on the dimensional accuracy and surface detail reproduction of the hydrophilic polyvinyl siloxane impression material. The moisture control remains an important factor for successful impressions.

Keywords: Hydrophilic Vinyl Poly Siloxane, Moistened Salivary Conditions, Prosthodontics.