A Three Month Comparative Evaluation of the Effect of Different Surface Treatment Agents on the Surface Integrity and Softness of Acrylic based Soft Liner: An In vivo Study

Introduction: Acrylic based soft liners are cost effective, yet are inferior in durability as compared to silicone based liners. Hence, this study was conducted to evaluate if the softness and surface integrity of acrylic based soft liner can be maintained by using different surface treatment agents. Aim: To comparatively evaluate the effects of Varnish, Monopoly and Kregard surface treatment agents on the surface integrity and softness of acrylic based soft liner at baseline, at one month and after three months. Materials and Methods: A total of 37 participants who required conventional maxillary dentures were selected according to the determined inclusion and exclusion criteria of the study. In the maxillary denture on the denture bearing surface, eight palatal recesses (5 mm x 3 mm) were made and filled with acrylic based soft liner (Permasoft). The soft liners in these recesses were given surface treatment and divided as control (uncoated), Varnish, Monopoly and Kregard groups. The hardness and surface integrity were evaluated with Shore A Durometer and Scanning Electron Microscope (SEM) respectively at baseline, one month and three months interval. Surface integrity between groups was compared using Kruskal-Wallis test. Intergroup comparison for hardness was done using ANOVA and Tukey's HSD post-hoc tests. Results: Amongst all the groups tested, surface integrity was maintained in the Kregard group, as compared to control, Varnish and Monopoly groups for all three time intervals (p< 0.001). Kregard treated samples also demonstrated significantly higher softness at all the time intervals (p<0.001). Conclusion: Surface treatment with Kregard demonstrated better surface integrity and softness at all the time intervals.