Volumetric changes and peri-implant health at implant sites with or without soft tissue grafting in the esthetic zone, a retrospective case-control study with a 5-year follow-up.

Abstract

To evaluate the volumetric changes and peri-implant health at implant sites with and without previous soft tissue grafting over a 5-year observation period. In 18 partially edentulous patients, dental implants were placed in the esthetic zone (15-25) with simultaneous guided bone regeneration, followed by submerged healing. During the healing phase, eight patients (test) received a subepithelial connective tissue graft, whereas 10 patients (control) did not receive any soft tissue augmentation. Subsequently, abutment connection was performed and final reconstructions were inserted. Impressions were taken 1week after crown insertion and at 5years. Obtained casts were scanned and superimposed for volumetric and linear measurements. The mean distance (MD) in the mid-buccal area between the two surfaces and the differences in buccal marginal mucosal level (bMMLchange ) and in ridge width (RWchange ) were evaluated. Peri-implant health was assessed using probing pocket depth (PPD) values, plaque index (PlI) and bleeding on probing (BOP). At a median follow-up time of 60.5months a median MD of -0.38mm (Min: -0.94; Max: -0.03) (test) and of -0.51mm (Min: -0.76; Max: 0.05) (control) was calculated. The level of the margo mucosae (bMMLchange ) demonstrated a median loss of -0.42mm (Min: -1.1; Max: -0.01) (test) and of -0.33mm (Min: -1.02; Max: 0.00) (control). The median RWchange ranged between -0.44mm and -0.73mm (test) and between -0.49mm and -0.54mm (control). Mean PPD values slightly increased, whereas PlI and BOP remained stable over time in both groups. None of the comparisons between the groups revealed statistically significant differences (P>0.35). A small sample size must be considered, however. Limited by a retrospective case-control study design, implant sites with and without soft tissue grafting on the buccal side revealed only minimal volumetric and linear changes and stability of peri-implant parameters over 5years.