A prospective clinical study of non-submerged immediate implants: clinical outcomes and esthetic results

Objectives: To evaluate healing of marginal defects in immediate transmucosal implants grafted with anorganic bovine bone, and to assess mucosal and radiographic outcomes 3-4 years following restoration. Material and methods: Thirty immediate transmucosal implants in maxillary anterior extraction sites of 30 patients randomly received BioOss (TM) (N=10; BG), BioOss (TM) and resorbable collagen membrane (N=10; BG+M) or no graft (N=10; control). Results: Vertical defect height (VDH) reductions of 81.2 +/- 5%, 70.5 +/- 17.4% and 68.2 +/- 16.6%, and horizontal defect depth (HDD) reductions of 71.7 +/- 34.3%, 81.7 +/- 33.7% and 55 +/- 28.4% were observed for BG, BG+M and control groups, respectively, with no significant inter-group differences. Horizontal resorption was significantly greater in control group (48.3 +/- 9.5%) when compared with BG (15.8 +/- 16.9%) and BG+M (20 +/- 21.9%) groups (P=0.000). Ten sites (33.3%) exhibited recession of the mucosa after 6 months; eight (26.7%) had an unsatisfactory esthetic result post-restoration due to recession. Mucosal recession was significantly associated (P=0.032) with buccally positioned implants (HDD 1.1 +/- 0.3 mm) when compared with lingually positioned implants (HDD 2.3 +/- 0.6 mm). In 19 patients followed for a mean of 4.0 +/- 0.7 years, marginal mucosa and bone levels remained stable following restoration. Conclusion: BioOss (TM) significantly reduced horizontal resorption of buccal bone. There is a risk of mucosal recession and adverse soft tissue esthetics with immediate implant placement. However, this risk may be reduced by avoiding a buccal position of the implant in the extraction socket.