Comparison of the Accuracy and Reliability of Instrumental Shade Selection Devices and Visual Shade Selection: An in Vitro Study.

Abstract

Objective: New shade-matching devices are available for clinical use, but their accuracy and reliability have not been investigated. This in vitro study compared the accuracy and reliability of a shade-matching colorimeter (Optishade), a spectrophotometer (VITA Easyshade V), and visual shade matching in simulated clinical conditions.

Material and methods: Shade matching was conducted with two digital devices; (Optishade and Vita Easyshade) and the visual shade selection method, with a new 16-tab Vita Classical shade guide. Shade tabs were placed within a gingival matrix and measurements were taken from the central area of each shade tab enclosed in a black box to simulate the oral cavity. Visual assessments were conducted independently by two examiners. For the reliability assessment, each shade tab was measured 20 times by each examiner. Accuracy was calculated as a percentage of the matching readings with the actual shade per each tab. Data were analyzed with the one-way ANOVA test (α = 0.05) and Pairwise Comparison (Bonferroni Post hoc Test) to assess accuracy. The reliability evaluation was conducted by comparison between both examiners using mean and standard deviation; by a two-tailed t-test for the independent samples for all the three groups included in the study.

Result: The shade matching accuracy of Optishade was 97.50%, Vita Easyshade 89.38%, and visual method 62.19%. Statistically, high significant difference in accuracy (p < 0.001) was found when comparing both Optishade and VITA Easyshade with the visual method. Additionally, there was statistically significant difference in accuracy (p < 0.05) when Optishade was compared to Vita Easyshade. The reliability of the Optishade was 99.6% and Vita Easy shade was 99.38%. Statistically, showed no statistically significant difference in the reliability of shade match obtained within the same group when comparing the readings of Examiner 1 and Examiner 2 (p > 0.05).

Conclusion: The colorimeter demonstrated the highest accuracy, followed by the spectrophotometer, and the visual shade selection method. Both digital methods investigated in this study showed comparable reliability.

Clinical implication: The results of this study emphasize the clinical advantage of digital shade-matching devices over visual shade-matching. The colorimeter offers high accuracy for shade matching and should be considered to use for shade matching especially with restorations in the esthetic zone.