Using digital photographs as a tool to assess the clinical color stability of lithium disilicate veneers: A clinical trial.

STATEMENT OF PROBLEM

Clinical information regarding the color stability of lithium disilicate veneers by using different methods of evaluation is scarce.

PURPOSE

This clinical trial aimed to evaluate whether digital photographs are a reliable method of clinically assessing the color stability of lithium disilicate veneers. Standardized digital photographs (ELAB) were compared with the VITA Easyshade spectrophotometer (ES) at baseline and at a 6-month follow-up.

MATERIAL AND METHODS

A split-mouth model was used in this randomized clinical trial to assess the performance of ceramic veneers (N=162), which were produced by either the CAD (IPS e.max CAD; n=81) or PRESS technique by heat pressing (IPS e.max PRESS; n=81), including the color dimension assessment. The ELAB evaluation was performed by making digital photographs with polarized light and a white balance (WhiBal) card. These data were transferred to the Adobe Lightroom CC2015 software program in RAW extension. The Digital Color Meter App (Apple) was used to measure L∗, a∗, and b∗ coordinates in this method. The ES color evaluation was performed with a spectrophotometer (Easy Shade) (control group) in the CIELab system. Measurements were performed 1 week after cementation (baseline) and at a 6-month follow-up. Data collected by the ELAB and ES methods were analyzed by a blinded calibrated operator to calculate ΔE by using the Mann-Whitney-Wilcoxon test (α=.05).

RESULTS

For all periods, the comparison among ELAB and ES methods (P=.331), CAD×PRESS by ELAB (P=.658), and CAD×PRESS by ES (P=.833) showed no statistically significant differences.

CONCLUSIONS

Standardized digital photographs (ELAB) were shown to be a straightforward and available resource for evaluating the color stability of lithium disilicate veneers, manufactured by CAD or PRESS.