Clinical and Radiographic Evaluation of Immediate and Delayed Single-tooth Implant Placement: An 18-month Follow-up Study

Background and aims. Maintenance of interdental soft tissue and the need for aesthetics are increasingly recognized as important criteria for implant success. The aim of this prospective clinical study was to compare the peri-implant and prosthetic conditions for single-tooth implants, placed according to the immediate (Im) and the delayed (De) placement protocols at 18-month follow-up examination. Materials and methods. After random allocation to the Immediate and Delayed groups, 14 patients were treated with a single-tooth implant in the anterior or molar region of the maxilla or the mandible immediately (Im) or 6 months (De) after tooth extraction, respectively. Patients attended a follow-up visit 18 months after implant placement corresponding to one year of loading of the implant restorations. Peri-implant and prosthetic parameters were evaluated clinically and marginal bone levels were measured on radiographs. Results. None of the implant restorations had failed after one year of function. Probing pocket depths decreased by up to 1.5 mm on average from the time of loading to the 18-month follow-up, no significant difference between the Im and De groups was found (4.3 versus 4.2 mm). A statistically significant radiographic marginal bone loss had occurred in the Im group (13.46%) as well as in the De group (15.62%) in the follow-up period. Conclusion. Soft and hard tissue responses to single-tooth implants placed either in the anterior or molar region of the maxilla or the mandible immediately (Im) or 6 months (De) after tooth extraction were similar in terms of the placement