Immediate occlusal loading of Brånemark System TiUnite implants placed predominantly in soft bone: 4-year results of a prospective clinical study.

Background: Immediate occlusal implant loading has been documented as a viable treatment option for various indications. However, most of the available studies reported on the short-term outcome of this treatment modality.

Purpose: The purpose of this prospective clinical study was to document, on a long-term basis, the outcome of immediate occlusally loaded Brånemark System Mk IV TiUnite (Nobel Biocare AB, Göteborg, Sweden) implants placed to support fixed reconstructions in various regions of the jaws.

Materials And Methods: Thirty-eight patients received a total of 51 fixed prosthetic reconstructions, all of which were connected on the day of implant insertion. Twenty restorations replaced single teeth, 30 were fixed partial dentures, and 1 was a full-arch fixed lower restoration. These prostheses were supported by 102 Brånemark System Mk IV TiUnite implants (38 maxillary and 64 mandibular), the majority of which were placed in posterior regions (88%) and mainly in soft bone (76%). Resonance frequency measurements and marginal periimplant soft tissue evaluations were conducted during the course of the study. Furthermore, radiographic examinations were performed at the time of prosthesis delivery and at the 1- and 6-month and 1-, 2-, 3-, and 4-year follow-up visits. This report summarizes the results after 4 years of loading.

Results: Three maxillary implants were removed, although stable, in one patient at the 8-week follow-up owing to postoperative infection in the adjacent guided bone regeneration area. No implants were lost further on. This resulted in a cumulative implant success rate of 97.1% after 4 years of prosthetic loading. The mean marginal bone remodeling after 4 years of function was 1.3 +/- SD 0.9 mm. At 4 years, absence of marginal plaque and bleeding on probing was reported for 87% and 69% of the sites, respectively, thereby remaining unchanged since the 1-year follow-up. On average, the interproximal soft tissue fill increased for both mesial and distal papillae from scores of 1.4 +/- 1.1 and 1.0 +/- 1.1, respectively, at the preoperative assessment to 2.0 +/- 0.8 and 1.7 +/- 0.8, respectively, at the 4-year assessment.

Conclusion: The applied immediate loading protocol, in combination with a slightly tapered implant design and a modified implant surface texture, was shown to be a successful treatment alternative in regions exhibiting soft bone.