Immediate Nonfunctional Loading of a Single Implant in the Posterior Maxillary Area: A Randomized Clinical Trial

: This study compared the clinical and radiographic outcomes of immediate nonfunctional loading of implants to conventional loading in the posterior maxilla. In this single-blind randomized clinical trial, a total of 39 implants were inserted and evaluated in 32 patients. Nineteen implants were in the control group, and 20 implants were placed in the test group. The test group received implants and immediate restoration within 72 hours after surgery; the control group was followed by a conventional loading protocol 4 months after surgery. Follow-up appointments were performed at 4, 6, and 12 months. Clinical assessment included measurement of implant stability through resonance frequency analysis (RFA), probing depth around the implant in four aspects, and survival rate. Radiographic assessment, including evaluation of crestal bone loss in the mesial and distal of the implants by parallel periapical radiography, was conducted. Twenty-nine implants were followed throughout the study period, completing the entire intended follow-up. No significant difference was seen between the test and control groups in terms of crestal bone loss at any interval either in mesial or distal aspects. Also, no significant difference was found between the two groups regarding implant stability. Probing depth did not show significant differences between groups at 6 and 12 months. Only one implant in the control group failed before prosthesis loading, and no failure was observed in the test group. Average of insertion torque in the control group and the test groups were 49 and 51 N/cm, respectively. This variable also showed no significant difference between the two groups. If appropriate primary stability is achieved, nonfunctional immediate loading of implants in the posterior maxilla may have similar results to conventional loading in this area. Using this protocol, the time of edentulousness could be minimized.