Esthetic Outcome and Tissue Stability of Maxillary Anterior Single-Tooth Implants Following Reconstruction with Mandibular Block Grafts: A 5-Year Prospective Study

Abstract

The aim of this prospective study was to evaluate the hard and soft tissue stability and esthetic outcomes of single-tooth implants placed in the anterior atrophic maxilla, following augmentation with mandibular block grafts covered with bovine hydroxyapatite and a resorbable collagen membrane, over a 5-year period. Patients with a bony deficiency of ≥ 3 mm horizontally and ≤ 3 mm vertically were treated consecutively with reconstructive procedures and implant placement 6 months afterward. Alveolar ridge dimensions were measured before and after augmentation using computed tomography. Clinical and radiographic measurements of soft and hard tissue levels and esthetic parameters (pink esthetic score [PES]) were performed annually to assess treatment outcomes. Twenty-nine patients were treated. One patient had partial graft exposure after 1 month that required regrafting at the time of implant placement. Mean bone gain was 4.23 ± 0.69 mm horizontally and 1.71 ± 0.75 mm vertically. The implant cumulative success rate was 100%, according to the criteria of Albrektsson et al. Mean crestal bone resorption after 5 years was low (0.61 ± 0.33 mm). Moderate recession of the facial mucosa (-1.12 ± 0.4 mm) was observed during the study period, while mesial and distal papilla heights increased slightly (0.13 ± 0.17 and 0.19 ± 0.37 mm, respectively). Mean PES ratings remained stable, varying from 9.07 ± 1.49 at the moment of definitive crown delivery to 8.61 ± 1.55 at 5 years. Only two cases (7%) were considered slightly below the defined threshold (PES = 8) of marginal esthetic acceptability. This study demonstrated that implants placed in anterior atrophic maxillae augmented with mandibular block grafts showed stable hard and soft tissue levels and reasonable esthetic outcomes over the medium term, although ongoing recession of the facial mucosa was observed.