Surgical therapy of peri-implantitis lesions by means of a bovine-derived xenograft: comparative results of a prospective study on two different implant surfaces

Objectives: The aim of this prospective study was to evaluate a regenerative surgical treatment modality for peri-implantitis lesions on two different implant surfaces. Materials and Methods: Twenty-six patients with one crater-like defect, around either TPS (Control) or SLA (Test) dental implants, with a probing depth (PD) >= 6 mm and no implant mobility, were included. The implant surface was mechanically debrided and treated using a 24% EDTA gel and a 1% chlorhexidine gel. The bone defect was filled with a bovine-derived xenograft (BDX) and the flap was sutured around the non-submerged implant. Results: One-year follow-up demonstrated clinical and radiographic improvements. PDs were significantly reduced by 2.1 +/- 1.2 mm in the Control implants and by 3.4 +/- 1.7 mm in the Test implants. Complete defect fill was never found around Controls, while it occurred in three out of 12 Test implants. Bleeding on probing decreased from 91.1 +/- 12.4% (Control) and 75.0 +/- 30.2% (Test) to 57.1 +/- 38.5% (p = 0.004) and 14.6 +/- 16.7% (p = 0.003), respectively. Several deep pockets (>= 6 mm) were still present after surgical therapy around Controls. Conclusions: Surface characteristics may have an impact on the clinical outcome following surgical debridement, disinfection of the contaminated surfaces and grafting with BDX. Complete fill of the bony defect seems not to be a predictable result.