Evaluation of Dimensional Changes in Denture Base Resins in Different Storage Medium

Abstract

The dimensional changes which take place in heat cure acrylic resins are shrinkage and expansion which influences the fit and occlusal relationship of the denture with the underlying oral mucosa. Despite the fact that acrylic resin polymer is known for its phenomenal properties, it has its own particular drawbacks and is not perfect in all its angles and one of these is dimensional change after processing was completed. The aim of the study was to determine linear dimensional changes of commercially available heat cure acrylic resins in four liquid medium. This in-vitro experimental study was conducted on four types of liquid medium (water, saline, artificial saliva, vinegar) with heat cure acrylic resins. Based on the number of mediums, five denture bases were determined for each group (N=20). Hence, each medium was allotted 5 denture bases which was 20 dentures in total. The dentures were allowed to be stored in the mediums for 4 weeks where every 2 days the dentures were placed in the cast were measured using digital vernier caliper to check for any distortion. The denture bases were measured in the posterior-palatal region, the interface between the cast and the denture . After four weeks, all the measurements that were taken, were compared with the base measurements, and analyzed. The data showed the dentures stored in vinegar and saline contracted 0.052mm and 0.040mm respectively and the dentures which were stored in water and artificial saliva contracted 0.031mm, 0.015mm respectively. A statistically significant difference between the storage media was observed(p<.05). Within the limitations of this study, water and artificial saliva were the best mediums to be used as a storage medium.