In order to diagnose impaired esthetics and evaluate treatments for these, it is crucial to evaluate all aspects of oral and prosthetic esthetics. No professionally administered index currently exists that sufficiently encompasses comprehensive prosthetic esthetics. This study aimed to validate a new comprehensive index, the Prosthetic Esthetic Index (PEI), for professional evaluation of esthetics in prosthodontic patients.

The content, criterion, and construct validity; the test–retest, inter-rater, and internal consistency reliability; and the sensitivity of the index were evaluated in 95 patients in need of oral rehabilitation.

The content validity was sufficient: Most correlations between aspects of the PEI were low (R > 0.5). The PEI was significantly correlated to the Dental Aesthetic Index (R = 0.52) and could distinguish between subgroups of patients indicating sufficient criterion and construct validity. The test–retest reliability showed an Interclass Correlation Coefficient (ICC) of 0.80, the internal consistency reliability showed a Cronbach's alpha of 0.7; and the inter-rater reliability was excellent, with an ICC of 0.94. The PEI could furthermore distinguish between participants and controls, indicating sufficient sensitivity.

The PEI is considered a valid and reliable instrument involving sufficient aspects for assessment of the professionally evaluated esthetics in prosthodontic patients.

With the validated PEI available, the clinician can directly assess and document the comprehensive esthetics of prosthodontic patients in a structured manner.