Augmented vs native posterior mandible: which bone hosts healthier implants at 15 years?

Does placing an implant in grafted bone compromise its long-term fate? Fifteen years of prospective data from two randomised controlled trials say the opposite — and the surprise runs counter to a common clinical instinct. Thirty-nine patients received 83 implants in the posterior mandible, either in native bone or in sites augmented solely with autologous bone. Clinical, radiographic, and patient-reported outcomes were tracked at baseline and at 1, 5, and 15 years.

Survival was high and almost identical: 94.7% in native bone, 95.3% in augmented bone. So far, a tie. But the peri-implant health picture diverged. Implants in native bone showed significantly more bleeding (P=0.022), higher gingival index (P=0.038), and deeper peri-implant pockets (P<0.001). Marginal bone loss from loading to fifteen years was also significantly greater in native bone (P=0.001), and peri-implantitis occurred less often in the augmented group (P=0.038). Patient satisfaction climbed in both groups and stayed high throughout.

The clinical reading is counterintuitive and worth sitting with. Augmentation here was not a compromise the bone had to overcome; the reconstructed sites behaved at least as well as native bone, and on every peri-implant inflammatory and bone-level metric, slightly better. The authors are careful — this is a small, single-cohort study with autologous grafts specifically — but the fifteen-year horizon is rare and valuable. For the surgeon weighing whether to augment a deficient posterior mandible or place a shorter implant in available native bone, this is evidence that grafted bone is not a liability over the long run, and may even host healthier peri-implant tissues. The mechanism is left open: whether the advantage comes from improved bone quality, more favourable implant positioning in reconstructed volume, or better soft-tissue conditions remains to be untangled.