Reconstructive surgical therapy of peri-implantitis: A multicenter randomized controlled clinical trial

Abstract

Objective: To evaluate the potential benefit of the use of a bone substitute material in the reconstructive surgical therapy of peri-implantitis.

Methods: In this multicenter randomized clinical trial, 138 patients (147 implants) with peri-implantitis were treated surgically, randomized by coin toss to either a control (access flap surgery) or a test group (reconstructive surgery using bone substitute material). Clinical assessments, including probing pocket depth (PPD), bleeding and suppuration on probing (BOP & SOP) as well as soft tissue recession (REC), were recorded at baseline, 6 and 12 months. Marginal bone levels (MBL), measured on intra-oral radiographs, and patient-reported outcomes (PROs) were recorded at baseline and 12 months. No blinding to group allocation was performed. The primary outcome at 12 months was a composite measure including (i) implant not lost, (ii) absence of BOP/SOP at all aspects, (iii) PPD ≤5 mm at all aspects and (iv) ≤1 mm recession of mucosal margin on the buccal aspect of the implant. Secondary outcomes included (i) changes of MBL, (ii) changes of PPD, BOP%, and buccal KM, (iii) buccal REC and (iv) patient-reported outcomes.

Results: During follow-up, four implants (one in the test group, three in the control group) in four patients were removed due to disease progression. At 12 months, a total of 69 implants in the test and 68 implants in the control group were examined. Thus, 16.4% and 13.5% of implants in the test and control group, respectively, met all predefined criteria of the composite outcome. PPD reduction and MBL gain were 3.7 mm and about 1.0 mm in both groups. Reduction in mean BOP% varied between 45% (test) and 50% (control), without significant differences between groups. Buccal REC was less pronounced in the test group (M = 0.7, SD = 0.9 mm) when compared to controls (M = 1.1, SD = 1.5 mm). PROs were favorable in both groups without significant differences. One case of allergic reaction to the antibiotic therapy was recorded. No other adverse events were noted.

Conclusions: Surgical therapy of peri-implantitis effectively improved the clinical and radiographic status at 12 months. While the use of a bone substitute material did not improve reductions of PPD and BOP, buccal REC was less pronounced in the test group. Patient satisfaction was high in both groups.

Keywords: bone graft; dental implant; peri-implantitis; reconstructive therapy; surgical therapy.

FIGURE 1

Flow‐chart illustrating the process of enrollment, treatment allocation and follow‐up

FIGURE 2

Images illustrating interventions by group allocation

FIGURE 3

Threshold and composite outcomes at 12 months. N = 147 implants, the four implants lost due to disease progression are considered. Composite outcome defined as implant not lost, no bleeding on probing (BOP), no suppuration on probing (SOP), probing pocket depth (PPD) ≤5 mm and buccal recession (REC) ≤1 mm. For further details, see Table A3.

FIGURE 4

Changes of probing pocket depth (PPD), bleeding on probing% (BOP%), buccal keratinized mucosa (KM), marginal bone level (MBL) and buccal recession (REC) following the surgical intervention. N = 143 implants, the 4 implants lost due to disease progression are not considered. Results are based on regressions analyses also illustrated in Table A5. Whiskers indicate 95% CIs.

FIGURE 5

Patient‐reported outcomes at baseline, at 2 weeks and at 12 months by group. Outcomes were scored on a VAS (100 mm). More details are reported in Table A6.

FIGURE A1

Flowchart illustrating the study outline

FIGURE A2

Illustration of radiographic evaluation of marginal bone levels at baseline and at 1 year. Images were calibrated by known distances (green line).

FIGURE A3

Questionnaires provided to study participants at baseline, at 2 weeks and at 12 months

FIGURE A4

Cumulative curves of continuous outcomes at 12 months by group. N = 143 implants. KM, keratinized mucosa; MBL, marginal bone level; PPD, probing pocket depth; REC, recession.

FIGURE A5

Patient‐reported outcomes at 12 months by group considering only subjects with treated implant sites in the esthetic zone (second premolar to second premolar in the maxilla). Outcomes were scored on a VAS (100 mm). N = 47 patients

FIGURE A6

Patient satisfaction by soft tissue recession considering only subjects with treated implant sites in the esthetic zone (second premolar to second premolar in the maxilla). N = 47 patients. VAS, visual analog scale

FIGURE A7

Illustration of potential center effect: Probing pocket depth change and marginal bone level change by center. N = 143 implants. Results of the statistical testing are illustrated in Table A12. MBL, marginal bone level; PPD, probing pocket depth.