Profilometric, volumetric, and esthetic analysis of guided bone regeneration with L-shaped collagenated bone substitute and connective tissue graft in the maxillary esthetic zone: A case series with 1-year observational study

Purpose The aim of this study was to evaluate 1-year stability and maintenance of peri-implant soft and hard tissues after guided bone regeneration (GBR) with L-shaped collagenated bone substitute and subepithelial connective tissue graft (CTG) in the maxillary anterior region using profilometric, volumetric, and esthetic analyses. Methods Fourteen peri-implant defects were grafted with L-shaped collagenated bone substitute, and 5 months after implant placement with GBR, reentry surgery in combination with CTG was performed in all participants. CBCT scans and STL files were acquired at baseline (after implant surgery, T1), reentry surgery (T2), and 1-year follow-up (T3). The profilometric and volumetric changes of the peri-implant tissues were measured, and the pink esthetic score (PES) was assessed at T3. Results One year after GBR and CTG at the buccal aspect of the maxillary esthetic zone, the mean thickness of the hard tissue (HT) decreased (HT0: -0.87 +/- 0.67 mm, HT1: -0.74 +/- 0.75 mm, HT2: -0.92 +/- 0.48 mm, 45-HT: -0.87 +/- 0.73 mm) and the corresponding thickness of the soft tissue (ST) increased (ST0: 0.96 +/- 1.06 mm, ST1: 0.85 +/- 0.95 mm, ST2: 0.38 +/- 0.82 mm, 45-ST: 0.12 +/- 0.62 mm), and as a result, there was no statistically significant difference in the total tissue thickness between T1 and T3 (p < 0.05). The mean volumetric changes of the peri-implant tissues increased after 1-year of implant surgery (T1-T2: 1.52 +/- 0.83 mm, T2-T3: -0.88 +/- 1.04 mm, T1-T3: 0.64 +/- 0.90 mm), and a statistically significant difference was shown in all compared time periods (p < 0.05). The mean PES score was 8.07 +/- 1.54 at T3 (range, 6-10). Conclusion Within the limitations of this 1-year follow-up study, GBR with an L-shaped collagenated bone substitute and subepithelial CTG in the maxillary esthetic zone was beneficial for stable and maintainable peri-implant hard and soft tissues.