Validation of different indices for the assessment of single tooth-supported prostheses in the esthetic zone: A feasibility clinical study

OBJECTIVES: To validate the reproducibility and inter-observer variability of 4 different indices Pink Esthetic Score/White Esthetic Score (PES/WES), Peri-Implant and Crown Index (PICI), Implant Crown Aesthetic Index (ICAI), and Copenhagen Index Score (CIS) in assessing the esthetics at single anterior maxilla tooth-supported prosthesis fabricated of 3 materials. MATERIAL AND METHODS: Eight observers, 2 from each dental specialty (Prosthodontics, Orthodontics, Periodontics, and Oral Surgery) evaluated 45 patient photographs, with 15 patients randomly assigned to 1 of 3 treatment groups: porcelain-fused-to-metal (PFM), monolithic zirconia, or lithium disilicate single tooth-supported prostheses. Standardized photographs of each prosthesis were assessed in comparison with the contralateral tooth using 4 esthetic indices: PES/WES, ICAI, CIS, and PICI. Inter-examiner reliability within each specialty group was analyzed using the Intraclass Correlation Coefficient (ICC). To evaluate the effects of the index type and dental specialty (as within-subject factors), treatment group (as a between-subject factor), and their interactions, an ANOVA-type test statistic (ATS) was applied. RESULTS: Among the evaluated indices, ICAI and CIS demonstrated the highest levels of interobserver agreement across all crown types, whereas PES/WES and PICI exhibited comparatively lower reliability. Post hoc test with Bonferroni correction revealed that ICAI consistently yielded significantly lower esthetic scores compared to all other indices across crown types. (P=.006), Inter-group comparisons based on PES/WES scores indicated that zirconia crowns achieved significantly higher esthetic ratings than both PFM (P<.001) and lithium disilicate crowns (P=.048). Intra-group comparisons showed that, for each specialty, scores assigned using PES/WES, PICI and CIS were significantly higher than those obtained with ICAI. CONCLUSIONS: Pattern differences among specialties varied depending on the esthetic index utilized, indicating a significant interaction effect between specialty and scoring system. CLINICAL SIGNIFICANCE: The findings of this study highlight that the choice of index significantly influences the esthetic assessment outcomes, and that certain indices may be more appropriate for detecting subtle esthetic differences, depending on examiner's clinical experience.