Alveolar Ridge Preservation Revisited: A Multimodal Evaluation of Bone Preservation and Regeneration—Preliminary Findings from a Randomized Controlled Clinical Trial

Alveolar ridge preservation using biomaterials is a well-established approach to counteract post-extraction bone resorption and optimize conditions for implant placement. However, most studies rely only on a single evaluation method and thereby risk overlooking essential aspects of alveolar regeneration. This preliminary analysis aimed to assess alveolar ridge preservation outcome using a multimodal approach combining histomorphometric, radiological, and image-based visualization methods. Twenty out of a planned 60 patients per group from an ongoing randomized controlled clinical trial were included. Patients were allocated to alveolar ridge preservation with a bone substitute material (BSM), a collagen-based material, a combination of both, or natural healing as control. Outcomes included CBCT-based volumetric analysis, histomorphometry, and primary implant stability via ISQ. Mineralized bone volume was significantly better preserved in bone substitute material groups compared to other groups, with BSM combined with collagen yielding the highest values. Histomorphometrically determined hard tissue fractions and implant stability were comparable across groups. Notably, CBCT-based visualization revealed non-ossified hypodense regions, so-called cavitations or covered socket residuum (CSR) within the former extraction sockets across all groups, independent of the biomaterial applied. BSM-based alveolar ridge preservation, particularly combined with a collagen membrane, most effectively maintained mineralized bone volume after extraction. Beside volumetric benefits, this preliminary in-dept analysis of the first part of the trial highlights cavitations/CSRs as a potentially underrecognized feature of post-extraction healing. Integrating quantitative with qualitative visualization-based assessments provides a more complete understanding of alveolar bone regeneration.