Optical behaviors of esthetic CAD-CAM restorations after different surface finishing and polishing procedures and UV aging: An in vitro study.

STATEMENT OF PROBLEM: Esthetic computer-aided design and computer-aided manufacturing (CAD-CAM) materials have various chemical compositions and can be prepared by using different finishing and polishing procedures. Their optical properties may change over time, depending on these factors. However, information about their stain resistance is still scarce.

PURPOSE: The purpose of this in vitro study was to evaluate the optical properties of esthetic CAD-CAM materials after different finishing and polishing procedures and ultraviolet (UV) aging.

MATERIAL AND METHODS: Lava Ultimate, Cerasmart, Vita Enamic, Vita Suprinity, and Vita Mark II materials were used. A total of 150 specimens (14×12×1 mm) were prepared (n=10). A spectrophotometer was used to measure color parameters after different finishing and polishing procedures (control, manual polishing, glazing) and ultraviolet (UV) aging. Lightness (L*), green-red (a*), blue-yellow (b*), chroma (Ch), and hue (h) parameters were recorded, and change in lightness (ΔE*) values were calculated. Statistical analyses were performed with 2-way ANOVA, the Fisher least significant difference test, and the paired samples t test (α=.05).

RESULTS: Significant interactions were noted between the aging conditions, material type, and finishing and polishing procedures for all evaluated parameters (P<.001). Vita Suprinity and Vita Mark II glazing groups resulted in significantly higher L1 * values (P<.05) after the first color measurements. The b1 * and C1 values of Vita Suprinity were higher than for other materials (P<.05). The highest ΔE* value was observed in the Lava Ultimate-glazing group (ΔE*=22.7) and the lowest in the Vita Mark II-control group (ΔE*=0.86).

CONCLUSIONS: The optical properties of CAD-CAM materials can be affected by the material type and the applied surface finishing and polishing procedure. Manual polishing seems to be a better choice for Lava Ultimate and Cerasmart and glazing for Vita Enamic. For ceramic materials, manual polishing or glazing can be recommended in terms of color stability.