Dealing with complications

The next speaker presented their case report involving a 55-year-old male patient who had a terminal dentition, with multiple teeth lost due to periodontitis. The patient was a heavy smoker, and wanted a fixed reconstruction. To this end, four implants in the maxilla and six in the mandible were planned. Surgical guides were prepared and implants were placed as part of a flapless approach. Next, impressions were taken and a provisional prosthesis was installed in 24 hours.

Eight months later, biomechanical complications began to appear in the maxillary all-on-4 reconstruction. The distal implant’s osseointegration had been lost; the abutment of the implant in the right central incisor had fractured; the prosthesis had broken in the right premolar area and the corresponding implant showed signs of bone resorption (fig 18–19). Since these complications were all signs of overloading, the option of re-placing the lost implant to restore the all-on-4 reconstruction was rejected. Instead, the decision was made to increase the number of implants in the maxilla. Approximately one year later, the final restoration was placed (fig 20–21).

The speaker concluded by analysing the potential reasons for these complications. They were classified as:

• patient factors: smoking, poor oral hygiene, history of periodontitis, bruxism 
• surgical factors: an all-on-4 protocol was selected to simplify the treatment without bone augmentation procedures; however, only four implants in the maxilla proved to be insufficient to compete with six in the mandible
• prosthetic protocol: the use of cantilevers in temporary dentures may have contributed to extra forces against the implants and represented the weakest points