Feasibility and needs for simultaneous or staged bone augmentation to place prosthetically guided dental implants after extraction or exfoliation of first molars due to severe periodontitis.

BACKGROUND: The aim of this study was to retrospectively assess bone volumes, healed ridge topography and possibility to plan prosthetically guided implants (PGI) at least 6 months after extraction or exfoliation of first molars as a consequence of terminal periodontitis (EEFMP).

MATERIAL AND METHODS: 45 subjects with Stage III-IV periodontitis providing 74 extraction sites (maxillary=51 and mandibular=23) were included. The degree of residual periodontal support on each root was assessed by combining periodontal and radiographic data. Digital planning of PGI with 4.8mm/4.1mm diameter, 8mm long, root-form dental implant and need for bone augmentation (BA) were performed using CBCT with a radiographic stent. Possibility of standard implant placement (STANDARD) and need for simultaneous or staged BA were assessed.

RESULTS: Planning PGI placement was possible in all cases. For a 4.8mm diameter implant, STANDARD was possible in 37.8 % of the sites, 33.8% required BA at the time of implant placement and 28.4% required staged BA before PGI. The use of 4.1 mm rather than 4.8 mm diameter implant allowed STANDARD in an additional 8.1% of cases that originally required simultaneous BA/osteotome sinus floor elevation (OSFE). The level of periodontal bone loss did not predict the complexity of implant placement, but significant differences were observed comparing maxillary with mandibular sites.

CONCLUSION: PGI planning at sites with first molar loss due to terminal periodontitis is possible but poses great challenge to rehabilitation, often requiring advanced augmentation procedures and sinus augmentation.