Effect of Connective Tissue Graft as an Adjunct to Guided Bone Regeneration in the Surgical Treatment of Peri-Implantitis: A Dual-Center Randomized Controlled Trial

Abstract

Objectives

To evaluate whether adding a connective tissue graft (CTG) to guided bone regeneration (GBR) improves clinical and radiographic outcomes in surgical peri-implantitis treatment.

Materials and Methods

Thirty-two patients with peri-implantitis were randomly assigned to receive GBR and CTG (test group, TG) or GBR alone (control group, CG). Clinical and radiographic parameters were recorded at baseline, 6, and 12 months. The primary outcome was the change in clinical attachment level (CAL), while secondary outcomes included pocket probing depth (PPD), bleeding on probing (BoP), plaque index (PI), keratinized mucosa width (KMW), mucosal thickness (MT), recession (REC), suppuration (SUP), marginal bone levels (MBL), bone defect morphology, and disease resolution (DR).

Results

At 12 months, CAL gain was significantly higher in TG compared with CG (3.21 ± 1.57 mm vs. 1.65 ± 1.28 mm; p = 0.022), and TG achieved significantly greater increase in KMW (2.25 ± 2.89 mm vs. 0.26 ± 1.49 mm; p = 0.010). Both groups showed significant PPD reduction, with a greater, though not statistically significant, improvement comparing TG with CG (3.25 ± 1.59 mm vs. 1.97 ± 1.23 mm; p = 0.052). Additionally, MBL improved significantly in both groups (p < 0.001), with higher gains in TG (p < 0.001). However, DR was comparable between the two groups.

Conclusions

GBR effectively improves peri-implant parameters after 1 year. Adding a CTG enhances CAL and KMW gains and may promote more favorable bone levels, although the impact on DR remains inconclusive. Long-term studies are warranted to confirm these findings.

Trial Registration

ClinicalTrials.gov NCT04323540