Immediate Versus One-Stage Restoration of Small-Diameter Implants for a Single Missing Maxillary Lateral Incisor: A 3-Year Randomized Clinical Trial

Background: The aim of this study was to compare the bone loss pattern and soft tissue healing of immediately versus one-stage loaded 3.0-mm-diameter implants in cases involving a single missing lateral maxillary incisor. Methods: Sixty patients with a missing lateral incisor in the maxilla were randomized to one of the treatments: 30 patients in the immediate-restoration group and 30 patients in the one-stage group. All implants were placed in healed sites and had to be inserted with a torque > 25 Ncm. The implants in the immediate- restoration group were fitted with a non-occluding temporary crown on the day of surgery. Both groups received a full occluding final crown 6 months after surgery. Mean marginal bone loss, probing depth, and bleeding on probing were assessed at 6-, 12-, 24-, and 36-month follow-up examinations by a masked examiner. Results: Sixty 3.0-mm-diameter implants were placed between July 2003 and February 2006; 27 (45.0%) were in men, and 33 (55.0%) were in women. All implants osseointegrated and were clinically stable at the 6-month follow-up. No statistically significant differences were observed for bleeding or plaque index. No implant fractures occurred. At the 36-month follow-up, the accumulated mean marginal bone loss and probing depth were 0.85 +/- 0.71 mm and 1.91 +/- 0.59 mm, respectively, for the immediate-loading group (n = 30) and 0.75 +/- 0.63 mm and 2.27 +/- 0.81 mm, respectively, for the one-stage group (n = 30). There was no statistically significant difference (P > 0.05) for the tested outcome measures between the two procedures. Conclusions: In the rehabilitation of a single missing lateral maxillary incisor, no statistically significant difference was assessed between immediately and one-stage restored small-diameter implants with regard to implant survival, mean marginal bone loss, and probing depth. Three-millimeter diameter implants proved to be a predictable treatment option in our test and control groups if a strict clinical protocol was followed. J Periodontol 2009;80:1393-1398.