Color stability of ceramic occlusal veneer with different translucency, designs and resin cement curing modes using “accelerated Artificial Aging”

Statement of problem: Clinically, Occlusal veneers is thin resin bonded restoration making color change liable to occur.
Purpose: The aim of the present study was directed to evaluate occlusal veneer color stability with different ceramic materials translucency, axial wall convergence angle and resin cement curing mode systems using “accelerated Artificial Aging”.
Materials and Methods: Eighty maxillary first molars were carefully selected and were divided into two main divisions (12 and 22 degree of convergence angle) (n=40), then each main division was divided into two groups (n=20) according to ceramic translucency (high and low translucency [HT and LT], finally, each group was subdivided into two subgroups (n=10) according to the type of used resin cement (light and dual cure). Occlusal surfaces were reduced leaving 5 millimeters. Shoulder finish line was made with 1mm thickness and 1.5 mm height. The occlusal surface was made using the Cerec scanner software’s design tools. The occlusal veneer specimens were cemented using light and dual cured resin cement. The initial color measurements were taken followed by accelerated aging process and finally, second color measurement was taken.
Results: The highest mean value of color variation (ΔE) was recorded at 12 ° convergence angle in the high translucent (HT) samples that have been cemented by light cured resin cement (2.01 ± 0.16), while the lowest mean value of color variation (ΔE) was recorded at 22 ° convergence angle in the low translucent (LT) samples that have been cemented by dual cured resin cement
(1.28 ± 0.11).
Conclusions: Color stability of occlusal veneer is apparently affected by ceramic translucency, degree of preparation convergence angle and curing mode of resin cement.