EFFECT OF THERMOCYCLING ON THE SURFACE ROUGHNESS OF LIGHT CURE DENTURE BASE RESIN - AN IN VITRO STUDY

Abstract

Introduction: Acrylic resins have been widely used in dentistry, especially in prosthodontics to fabricate different types of prostheses, including complete and partial dentures, temporary fixed partial dentures, maxillofacial prostheses and implant-supported over dentures. The introduction of visible light-cured (LC) acrylic resins is the major breakthrough in the application of acrylic resins in the field of dentistry, which are urethane dimethacrylate-based. The aim of this study was to evaluate the effect of thermocycling on the surface roughness of light cure denture base resin.

Materials and methods: Ten pellets of light cure denture resins were prepared with a circular disc, diameter and thickness (10 x 10 x 4 mm). Later, it was polished using poly buff brushes and polishing paste followed by a wet rag wheel with a slurry of  pumice. For thermocycling, the TC 4 SD mechatronik thermocycler was used. The temperature set for cold  was 10° Celsius and for hot was 60° celsius. Number of cycles to be undergone was 1000 cycles which equates to 6 months in alternative hot and cold temperatures. The time taken to dwell was 30 seconds for each and the time taken was 10 seconds each for draining. A stylus profilometer was used to check the surface roughness before and after thermocycling.

Results: There were no significant changes in Ra, Rq and Rz values of light cure denture base resin before and after thermocycling. The P-value obtained was 0.157 (< 0.05) hence not statistically significant.

Conclusion: From this study, it can be concluded that thermocycling does not affect the surface roughness of light cure denture base resin.