A Comparison of Esthetic Features of Pre-existing Natural Tooth Versus Post-Implant Restoration in the Esthetic Zone: A Retrospective 12-month Follow-up.

Purpose: To correlate the link between natural teeth located in esthetic regions of the arches before extraction with their definitive dental implant restorations, and to propose a new and contemporary esthetic index based on the natural dentition (EIND) preoperatively.
Materials and Methods: Patients possessing a high smile line with teeth requiring implant replacement therapy in the maxillary anterior region were included. Clinical intraoral photographs and periapical digital radiographs taken before extraction and 10 ± 1.5 months (range: 9 to 12 months) after the delivery of implant-supported permanent restorations were used to make the measurements and evaluations according to the proposed index. Pink esthetic score (PES) parameters were analyzed. Statistical analyses of preimplant and postimplant parameters between tooth sites and implant sites were carried out with a computer software program.
Results: The study included 51 patients (35 women, 16 men), with a mean age of 39.6 years, with a total of 83 dental implants placed in the maxillary anterior region. Of these, there were 6 right canines, 22 right lateral incisors, 11 right central incisors, 22 left central incisors, 17 left lateral incisors, and 5 left canines. Of the 83 included implants, 67 were immediately and 16 were delayed placed. Statistical analyses between tooth sites and implant sites showed significant differences in tissue contour (P = .001), texture (P = .001), alveolar deficiency (P = .001), and total PES (P = .007). No statistically significant difference was detected in mesial papilla, distal papilla, tissue margin, tissue biotype, and the amount of keratinized mucosa. Additionally, R2 value presented a higher variance and lower predictable values of peri-implant tissue parameters compared with those of the natural dentition.
Conclusion: This study analyzed various periodontal and peri-implant soft and hard tissue parameters, and a new index system, EIND, was proposed. This index could be used to collect the esthetic-related parameters for pre-extraction treatment planning and provide valuable information for esthetic risk assessment.