Aim: The purpose of this study was to evaluate the effects of three different surface treatments on the color stability of ultra-translucent zirconia occlusal veneers before and after thermal cycle aging.
Materials and methods: Twenty-eight maxillary premolars were embedded in resin blocks, and minimally occlusal veneer preparation was made. All prepared teeth were scanned using the Cerec scanner. The veneer restorations were designed and milled. The teeth samples were divided into four groups (n = 7) according to the type of surface treatment performed on the intaglio surface of veneer restoration; group I: No surface treatment (Control), group II: Air-particle borne abrasion, group III: Er, Cr: YSGG laser, group IV: Ceramic primer (MDP). The restorations were cemented using dual-curing resin cement. The veneer samples' color was measured using a spectrophotometer according to the CIE L*a*b* color before and after thermal cycles. Then, the color difference (ΔE) for the surface-treated specimens before and after aging was measured. The data was investigated statistically with a significance value of p < 0.05.

Results: Significant differences in the mean color change (ΔE) values were observed between all surface-treated groups. Before and after aging, the veneers with air abrasion showed the highest color change followed by the laser. The MDP primer showed the least color change. There was no statistical difference between each group before and after thermocycling

Conclusions: Surface treatment had resulted in a color change of ultra-translucent zirconia and air-borne particle abrasion had the highest significant effect. Thermal cycling had no significant effect.