Spectrophotometric analysis of clinical factors related to the color of ceramic restorations: A pilot study.

STATEMENT OF PROBLEM: Shade matching natural teeth with ceramic restorations is still an esthetic, clinical challenge.

PURPOSE: The purpose of this prospective clinical study was to evaluate the influence of color-related factors on the color variation of ceramic restorations based on spectrophotometric analysis.

MATERIAL AND METHODS: Color records were obtained from 11 participants who received 38 lithium disilicate restorations. CIELab color coordinates were measured with a spectrophotometer on the ceramic restoration, tooth (baseline), prepared tooth, and luted ceramics. Color variation (ΔE00 ) was calculated for each variable (luting agent and restoration type, tooth substrate shade, ceramic thickness, and translucency parameters) measured at baseline on the prepared tooth and after cementation of the restorations. Confidence intervals (CI) for the means (95% CI) were calculated, and the ΔE00 values and CIELab individual color coordinates were compared for each pair of variable by using the Student t test or Welch test (α=.05).

RESULTS: Greater color variation values were observed between measurements obtained on the prepared tooth and luted restoration. The lower ΔE00 values were observed over darker tooth substrate measured at baseline and after luting (P=.007).

CONCLUSIONS: The 3 conditions evaluated presented clinically visible color differences, highlighting the importance of clinical evaluations on the visual color acceptability limits for restorations, which are usually defined in laboratory studies. The lithium disilicate ceramic showed lower masking ability over darker tooth substrate, whereas the coordinates L*, a*, and b* were cementation-dependent.