Provisional resin‐bonded bridges following All‐on‐4 5 6 implant placement‐ technical and biological complications

Background Immediate provisional loading at the day of implant placement according to the All-on-4 5 6-concept offers major benefits for the patient, such as total avoidance of removable prostheses and no need to adapt to changes regarding function, esthetics as well as phonetics. Aim/Hypothesis The aim of this study was to evaluate the durability of provisional resin-bonded bridges (glass-fibre reinforced, no cantilevers) after full arch implant at placement in edentulous patients. Material and Methods This retrospective analysis included patients that received full-arch implant therapy with at least 4 implants at the Academy for Oral Implantology in Vienna between 2005 and 2014. (765 jaws). Complications that occurred within a wearing period of at least 3 months were analyzed. Moreover, a causal relationship between duration of wear and the number of complications was investigated. Results A total of 3609 implants were placed in 478 upper and 278 lower jaws. In 60 female and 53 male patients both jaws were treated simultaneously. The rate of technical complications was 38%, however, three quarters were considered minor and could be solved chairside. Major complications (requiring lab technicians) were seen in only 15% and the implant failure rate was 2.2%. Biomechanical complications (veneer fracture, chipping, abutment or screw loosening, screw access channel fillings) were most frequent (64%). 75% of implant failures occurred within the first 9 months, while technical complications were low after 6 months and started accelerating not before the first year of loading. The average retention period of the provisional bridge was 240 days for the upper and 211 days for the lower jaw (median- 140 days). The median time until the first complication occurred was 29 days. Conclusion and Clinical Implications Technical complications with resin-bonded glass-fibre reinforced full-arch implant bridges are frequent within the first 6 months after immediate provisionalization, however, 75% of the complications could be solved chairside and only 15% need extensive repair. Extending the provisional phase to up to 1 year does not significantly increase rates of biomechanical complications.