To Compare and Evaluate the Surface Roughness, Colour Stability and Wear Resistance of Light Cured Composite Coating Material on Hybrid Ceramic Material and Composite Resin Denture Teeth

BACKGROUND: Chairside characterization material is becoming popular in recent times. It is a light cure based composite coating material and can be used during esthetic restorative procedures. In addition to its excellent esthetic outcome, it can alter the surface defects thereby acting as a surface sealant and providing a smooth lustrous surface. There is no such evidence available regarding the surface roughness, colour stability and wear resistance of this characterization material on long term clinical scenarios. AIM OF THE STUDY: To evaluate the colour stability, surface roughness and wear resistance of light-cured composite coating material on hybrid ceramics and composite resin denture teeth. MATERIALS AND METHODS: A total of 40 disc-shaped specimens were prepared into a size of 6mm x 2mm from Hybrid ceramic block (Group 1, n=20) and composite resin denture teeth (Group 2, n=20). Both Group 1 and Group 2 specimens were subjected to coating with Light cured composite coating material (Optiglaze GC, GC America) and were subjected to simulated oral conditions like thermocycling and tooth brushing. All the specimens were then tested for surface roughness, colour stability and wear resistance. The results were statistically analyzed using SPSS Software version 21.0. R-ANOVA and paired t-test were done with the Significance level set as 0.05. RESULTS: The mean surface roughness(Ra) of Group 1(Hybrid ceramic) before and after coating were obtained as 3.213μm,1.800μm and that of Group 2 (composite resin denture teeth) specimens before and after coating were obtained as 4.218μm and 2.684μm respectively. The surface roughness value Ascended to 2.413μm after subjecting to thermal ageing. The mean colour change ΔE values for Group 1 and Group 2 are 0.802 and 0.681 respectively which is statistically insignificant with a p-value of 0.843. The total percentage of mass loss of the coating material after wear testing for Group 1 and Group 2 is 3.07% and 3.11% respectively and in that 3% from Group 1 and 2.6% from the Group 2 were lost during thermocycling. CONCLUSION: Application of light cured composite coating greatly improved the surface properties of both hybrid ceramic and composite denture teeth. The colour stability of this composite coating material was excellent even after subjecting it to thermal ageing suggesting that it can be used as characterization material without much colour degradation over a period of time. The wear resistance of light cure coating material on composite resin denture teeth is high when compared to Hybrid ceramic as there was more coating material loss in the hybrid ceramic specimen when subjected to thermal ageing