A multicenter 12-month evaluation of single-tooth implants restored 3 weeks after 1-stage surgery

The time-intensive, multi-step process of dental implant therapy limits patient acceptance. This 3-year prospective multicenter study sought to determine the safety of an expedited therapy that consisted of loading unsplinted maxillary anterior single-tooth implants 3 weeks after 1-stage surgical placement, and determination of the peri-implant cortical bone and mucosal responses to the expedited procedure. Fifty-two patients missing 1 or 2 maxilliary anterior teeth were enrolled in a study approved by the Institutional Committee on Human Subjects Research and based on strict inclusion and exclusion criteria. Astra Tech ST implants placed in a 1-stage procedure were restored 3 weeks later with ST abutments and a provisional crown (baseline); 7 to 9 weeks later, a porcelain-fused-to-metal or all-ceramic crown was cemented. Radiographic and clinical examinations were made at baseline and at 6 and 12 months. Implant survival was recorded. Cortical bone responses and peri-implant mucosal responses were evaluated. Fifty-eight implants were placed. During the 3-week period after implant placement, 4 patients were dismissed because of smoking cigarettes (a protocol deviation), and 1 patient was excluded because of deviation in loading time. Of the remaining 53 implants, 2 failed before definitive crown cementation. The resultant 96.2% survival rate was independent of implant length, tooth position, and bone quality/quantity. The mean change in marginal bone level was 0.4 mm at 12 months. The number of surfaces with plaque decreased from 3.4% at baseline to 0.5% at 12 months. The surfaces with inflammation also decreased. A mean gain in papilla length of 0.61 mm occurred, and a gain in buccal gingiva (x = 0.34 mm) was observed. A high success rate with positive tissue responses was achieved for maxillary anterior unsplinted single-tooth implants placed in a 1-stage surgery and restored at 3 weeks. This 2-component system is suited to a single-stage, rapid loading protocol for esthetic single-tooth replacement.