A comparative evaluation of colour stability of different resin cements and its influence on the final shade of All-Ceramic Restorations: An in-vitro Study

Introduction: Colour changes of the luting material can become clinically visible affecting the aesthetic appearance of thin ceramic veneers. Therefore, unfortunately, the long-term success of veneers is tied to the colour stability of the luting agent used to cement them. Aim: To compare the colour stability of different resin cements and its influence on the final shade of overlying ceramic using two different thicknesses of ceramic. Material and Methodology: Sixty disc-shaped specimens of high translucency (HT) A2 shade of two thicknesses (0.5 mm & 1 mm) were prepared from lithium disilicate glass-ceramic. The discs of each thickness were further divided into three groups randomly depending upon the resin cements used. Group A - light cure resin cement - Variolink N LC by Ivoclar Vivadent in clear shade, Group B - base paste of dual-cure resin cement - Variolink N by Ivoclar Vivadent in transparent shade and Group C dual-cure resin cement - Clearfil esthetic cement EX by Kuraray in clear shade were used to compare their colour stability. A spectrophotometer was used for the colour measurements of the specimens before and after accelerated ageing. The colour stability was determined by colour differences (ΔE) using the coordinates L*, a* and b* in the pre and post accelerated ageing. Results: On comparing the three resin cements, Group A showed the lowest ΔE, whereas the highest ΔE was observed in Group B. This finding was constant for discs of both thicknesses. Conclusion: Even though statistically significant results were observed between the groups, they were not visibly differentiable.