Autogenous bone (AB) blocks harvested from intraoral donor sites (i.e., retromandibular, chin) are the most commonly used procedure for lateral alveolar ridge augmentation [1]. However, despite significant horizontal bone gains, cortical bone blocks were noted to undergo an incomplete replacement resorption [2, 3], thus featuring a composition of non-vital residual and newly formed vital bone in the former defect area [4]. Moreover, AB blocks are prone to a rapid degradation and therefore commonly combined with contour augmentation procedures using slowly resorbing particulate grafts and barrier membranes [5].

Recent experimental studies have focused on the use of extracted tooth roots (TR) as an alternative scaffold to support bone regeneration at non-self-contained lateral alveolar ridge defects. Various outcome measures based on histological, immunohistochemical, and micro-computed tomographic analyses did not significantly differ between differently conditioned TRs (i.e., healthy, endodontically treated non-infected, periodontally diseased) and retromolar AB grafts [4, 6, 7]. The median bone-to-implant contact (BIC) values at 3 weeks following implant placement ranged from 36.96 to 50.79% in the TR group and from 32.53 to 64.10% in the AB group [4].

These preclinical data have recently been in an initial human case report [8] as well as in a prospective controlled clinical study [9]. In particular, soft tissue healing was uneventful in both TR and AB groups. The crestal ridge width at 26 weeks (CW26) amounted to 10.06 ± 1.85 mm (median 11.0) in the TR group and 9.20 ± 2.09 mm (median 8.50) in the AB group and allowed for a successful implant placement in all patients investigated [9].

The aim of the present analysis was to assess and compare the radiographic outcomes in both groups.