The influence of professional competence on the inter- and intra-individual esthetic evaluation of implant-supported crowns in the anterior maxilla

Objectives: Evaluation of the influence of professional competence on esthetic predictability of implant-supported crowns in the anterior maxilla and identification of objective factors allowing predictable planning for esthetic results.

Materials and methods: Sixty patients with 82 implants in the esthetic zone were included in this study. Width of keratinized mucosa, biotype, recessions, and papilla index according to Jemt as well as radiological bone loss were assessed. Study casts and photographs were obtained. Each patient as well as people with different level of expertise (laypersons, students and dentists) rated the esthetic satisfaction after final restoration on a scale (1-10). Correlations between esthetic assessments and previously documented clinical parameters were tested.

Results: The study failed to show a significant relationship between the raters' level of dental expertise and their subjective esthetic evaluation. However, patients rated themselves much more favorable than the three evaluator groups did. A comparison of the clinical parameters with the esthetic evaluation revealed significantly more favorable ratings by the lay group in the presence of a wide attached gingiva (P = 0.021) than by the other groups and by the laypersons (P = 0.002), the dentists (P = 0.003), and students (P = 0.009) in the absence of recessions. The ratio of the implant crown length to the length of the contralateral crown had a negative effect on ratings for all three groups ([laypersons P < 0.001], [students P < 0.001] and [dentists P = 0.001]). The papilla index of the mesial papilla correlated significantly with laypersons' ratings (P = 0.036).

Conclusion: Earlier investigations are confirmed. Width of keratinized mucosa is a risk factor for esthetic predictability of implant-supported crowns in the anterior maxilla in laypersons' ratings. Furthermore, there is an association between the discrepancy of lengths of implant-supported single crowns to their contralateral natural teeth and esthetic satisfaction for all expertise levels.