Comparison of a polyethylene glycol membrane and a collagen membrane for the treatment of bone dehiscence defects at bone level implants-A prospective, randomized, controlled, multicenter clinical trial.

Abstract

The aim of the present randomized, controlled clinical multicenter trial was to compare a polyethylene glycol (PEG) and a native collagen membrane (BG) for simultaneous guided bone regeneration at bony dehiscence-type defects around bone level titanium implants. The study enrolled 117 patients requiring implant treatment in the posterior maxilla or mandible with expected buccal bony dehiscence-type defects at the placed titanium implants. According to a parallel groups design, defects were filled with a synthetic bone filler and randomly assigned to either PEG or BG membrane. As primary parameter, the relative vertical bone fill was assessed at baseline and at re-entry after 6months of healing. As secondary parameters, the marginal bone level (MBL) was assessed radiographically and soft tissue conditions were recorded up to 18months postloading. Both groups showed comparable vertical bone fill revealing a relative change in defect height of 59.7% (PEG) and 64.4% (BG). The absolute mean reduction in defect size was 2.5mm in the PEG group and 3.2mm in the BG group. Although both groups revealed a statistically significant mean defect reduction (p<.001), a comparison between the two groups did not show statistical significances. The non-inferiority test with inferiority limit of -5% could not be rejected, based on the 90% confidence interval of the differences of the two means with lower limit -15.4%. After 18months, an MBL increase of 0.45±0.43mm in the PEG group and 0.41±0.81mm in the BG group was detected (p<.001). Soft tissue complications were observed in both groups without showing statistical significance. Both membranes supported bone regeneration at dehiscence-type defects and obtained vertical bone fill with a relative change in defect height of 59.7% (PEG) and 64.4% (BG); however, the non-inferiority of PEG could not be shown.