The Use of a Resorbable Membrane as an Adjunct to a Xenogeneic Bone Replacement Graft in the Reconstructive Surgical Therapy of Peri‐Implantitis: 3‐Year Results of a Randomised Clinical Trial

ABSTRACT Aim To evaluate the effect of the adjunctive use of a resorbable collagen membrane in the reconstructive surgical therapy of peri‐implantitis. Material and Methods Forty‐three patients (43 implants) diagnosed with peri‐implantitis underwent surgical treatment using a reconstructive approach, which included a bone substitute material with (test) or without (control) a resorbable collagen membrane. Supportive peri‐implant treatment was administered biannually during the 3‐year follow‐up period. Clinical outcomes, such as probing pocket depth (PPD), bleeding on probing (BOP), suppuration on probing (SOP), marginal mucosal level (REC) and keratinised mucosa width (KM), were recorded at baseline, as well as at 6, 12 and 36 months. Radiographic marginal bone levels (MBLs) and patient‐reported outcomes (PROs) were also evaluated. The primary outcome was a composite measure consisting of PPD ≤ 5 mm, absence of BOP/SOP and buccal REC of ≤ 1 mm. A second composite outcome, termed ‘disease resolution’, was also assessed, defined as PPD ≤ 5 mm, BOP at ≤ 1 site and complete absence of SOP. Results Out of the 43 participants, 8 were lost to follow‐up, 2 experienced implant loss and 1 was surgically re‐treated. At 3 years, the composite outcome was achieved for 25.0% of implants (test: 17.6%; control: 27.8%), while disease resolution was achieved for 31.2% (test: 29.4%; control: 27.8%). Overall, PPD and BOP were reduced by 3.6 ± 3.2 mm and 37.5% ± 42.1%, respectively. Changes in buccal REC and KM were 0.5 ± 1.3 and 1.1 ± 1.5 mm, respectively. An overall bone gain (MBL change) of 1.0 ± 2.2 mm was observed. PROs were favourable. No statistically significant differences were observed between groups. Conclusion Adding a collagen membrane to a bone substitute material in the surgical treatment of peri‐implantitis did not yield any benefits regarding clinical, radiographic or patient‐reported outcomes. Trial Registration: ISRCTN67095066 ( https://www.isrctn.com/ISRCTN67095066 )