RCT of Patients Treated with Immediately Loaded Implant-Supported Fixed Prostheses

Objectives: To test the null hypothesis that immediate loading of dental implants in the edentulous mandible with a fixed prosthesis has no benefits compared to a traditional loading technique in terms of implant survival, clinical function, short-term prognosis and patient quality of life.

Methods: A parallel randomized controlled trial with 2 study arms was approved by the Research Ethics Board and initiated in 2006. Forty two participants have been recruited amongst patients seeking implant supported prostheses at the Faculty of Dentistry Implant Prosthodontic Unit (IPU). Four TiUnite dental implants (NobelBiocareŽ, Gothenburg, Sweden) were placed following the standard surgical protocol. Immediately after surgery, the allocation envelope, provided by a third independent part that conducted the randomization, was opened in order to allocate patients to either arm of the study. In the experimental group, multi-unit abutments were placed and mandibular denture was converted into an interim Implant-Supported Fixed Bridge (ISFB) on the same day of surgery. The permanent (ISFB) was fabricated 10-14 days later. In the control group, the implants remained unloaded for 3 months. Clinical evaluation was performed by an independent, blind investigator. Further outcomes will be measurements of quality of life profile and patient mediated cost effectiveness analysis of treatment. Results: Early clinical results show no significant difference in implant success and clinical function between the two study arms. Frequency of prosthetic complications and number of dental visits in the period between implant placement surgeries and insertion of final prostheses were significantly more frequent in the control group. Both groups showed an improvement in the mean overall OHIP, functional and psychological subscales. Conclusion: This study suggests that immediate loading of four dental implants with a fixed prosthesis in the edentulous mandible is a feasible treatment option and leads to a substantial improvement in perceived oral health status.