Proposal for a gingival shade guide based on in vivo spectrophotometric measurements

PURPOSE: The purpose of this study was to propose and assess a shade guide for pink gingival aesthetics using a Spanish population sample. MATERIALS AND METHODS: The L*, C*, h, a* and b* coordinates of 259 participants were measured using a spectrophotometer in 3 standardized points along the attached gingiva of the maxillary central incisors. A hierarchical clustering analysis was applied to obtain separate solutions regarding the number of shade tabs. For each of the solutions obtained, color differences (ΔE*) were calculated using the CIELab and CIEDE2000 formulas, and the proposed shade guide was selected considering (1) the color differences between tabs and (2) the coverage error of each of the solutions. RESULTS: The proposed shade guide consisted of 8 gingival shade tabs and achieved CIELab and CIEDE2000 coverage errors of less than the respective 50:50% acceptability thresholds (ΔE*=4.6 units and ΔE₀₀=4.1). The coordinates for the various gingival shade tabs were as follows: Tab 1: L*43.3, a*21.9, b*12.3 (1.6); Tab 2: L*42.9, a*34.1, b*19.1; Tab 3: L*46.5, a*25.8, b*10.9; Tab 4: L*46.5, a*27.3, b*15.1; Tab 5: L*49.6, a*23.5, b*16.8; Tab 6: L*51.5, a*19.7, b*13.6; Tab 7: L*55.9, a*22.0, b* 15.0; and Tab 8: L*56.0, a*19.9, b*18.8. CONCLUSION: The CIELab and CIEDE2000 coverage errors for the 8 shade tabs of the proposed gingival shade guide were significantly lower than those of other guides. Therefore, despite the limitations of this study, the proposed guide is more appropriate for matching gingival shade in the Spanish general population.

Study of the most frequent natural tooth colors in the Spanish population using spectrophotometry

PURPOSE: To identify the most frequent natural tooth colors using the Easyshade Compact (Vita -Zahnfabrik) spectrophotometer on a sample of the Spanish population according to the 3D Master System. MATERIALS AND METHODS: The middle third of the facial surface of natural maxillary central incisors was measured with an Easyshade Compact spectrophotometer (Vita Zahnfabrik) in 1361 Caucasian Spanish participants aged between 16 and 89 years. Natural tooth color was recorded using the 3D Master System nomenclature. The program used for the present descriptive statistical analysis of the results was SAS 9.1.3. RESULTS: The results show that the most frequent dental color in the total sample studied is 3M1 (7.05%), followed by the intermediate shade 1M1.5 (6.91%) and 2L1.5 (6.02%). CONCLUSION: According to the research methodology used, and taking into account the limitations of this study, it can be proposed that the most frequent color among the Spanish population is 3M1; the most common lightness group is 2; the most frequent hue group according to the 3D Master System is M and the most frequent chroma group is 1.5.