Effect of Temperature on the Dimensional Accuracy of Irreversible Hydrocolloid Material at Different Storage Time Intervals

Abstract

Aims: In this competitive arena, dentists are inevitably searching for dimensionally more stable and accurate material to produce precise, effective prosthesis. Amongst many impression materials used on a day-to-day basis, irreversible hydrocolloid impression materials are most commonly utilized due to easy manipulation, hydrophilic nature, elastic recovery, accuracy and cost-effectiveness. The main objective of this study was to observe the effect of temperature and storage time on the accuracy of an irreversible hydrocolloid material.
 Study Design: Experimental and in-vitro study.
 Place and Duration of Study: Department of Prosthodontics and Research Medical Centre, Liaquat University of Medical and Health Sciences, Jamshoro, February 2019 to July 2019.
 Methodology: Total one hundred and five impressions cast models were made using irreversible hydrocolloid impression material (Hygedent) from ideal maxillary dentoform model. There were three temperatures (25°C,35°C and 45°C) and two storage timings (15 minutes and 25 minutes) along with one control group (immediate pouring). Measurements were taken utilizing digital Vernier Caliper. On each cast, two measurements were recorded in a linear manner including anteroposterior (AP) and Cross arch (CA).
 Results: Results revealed that there is a significant difference between anteroposterior dimensional changes of distance from Mesial surface of maxillary right central incisor to distal surface of maxillary right first molar and cross-arch dimensional changes of distance from distal surface of maxillary right first molar to distal surface of maxillary left first molar at different storage temperatures and time intervals. This indicates that the dimensions are increasing directly as storage time and temperature increases which might be because of shrinkage of material due to increase in time of pouring. Shrinkage causes material to pull it towards the tray and increase the dimensions.
 Conclusion: This study concluded that the best results could be obtained with immediate pouring at 25°C temperature as compared to other observed temperatures.