Five-year results of a randomized controlled clinical trial comparing zirconia and titanium abutments supporting single-implant crowns in canine and posterior regions

Objectives To test the survival rates, and the technical and biological complication rates of customized zirconia and titanium abutments 5 years after crown insertion. Material and methods Twenty‐two patients with 40 single implants in maxillary and mandibular canine and posterior regions were included. The implant sites were randomly assigned to zirconia abutments supporting all‐ceramic crowns or titanium abutments supporting metal‐ceramic crowns. Clinical examinations were performed at baseline, and at 6, 12, 36 and 60 months of follow‐up. The abutments and reconstructions were examined for technical and/or biological complications. Probing pocket depth (PPD), plaque control record (PCR) and Bleeding on Probing (BOP) were assessed at abutments (test) and analogous contralateral teeth (control). Radiographs of the implants revealed the bone level (BL) on mesial (mBL) and distal sides (dBL). Data were statistically analyzed with nonparametric mixed models provided by Brunner and Langer and STATA (P