To develop and validate a CBCT-based three-dimensional volumetric analysis method for assessing infrabony defect regeneration, overcoming limitations of conventional two-dimensional radiographic evaluation. Pre- and post-treatment CBCT scans (DICOM 3.0 format) from a case undergoing guided tissue regeneration were reconstructed using Mimics Research 21.0 and exported as STL files. Three-dimensional defect models were segmented and analyzed using Geomagic Wrap software, with standardized defect volume measurements obtained through a reproducible coordinate system. A reliable reference plane was established using adjacent dental anatomy, enabling consistent volumetric assessment across serial CBCT scans. Quantitative three-dimensional analysis revealed significant changes in infrabony defect volume following regenerative therapy, providing comprehensive evaluation of bone regeneration patterns. This novel volumetric assessment method offers clinicians and researchers an accurate three-dimensional alternative to traditional 2D imaging for evaluating periodontal regeneration outcomes, addressing critical limitations of conventional radiographic analysis.

Periodontitis is caused by overactive osteoclast activity that results in the loss of periodontal supporting tissue and mesenchymal stem cells (MSCs) are essential for periodontal regeneration. However, the hypoxic periodontal microenvironment during periodontitis induces the apoptosis of MSCs. Apoptotic bodies (ABs) are the major product of apoptotic cells and have been attracting increased attention as potential mediators for periodontitis treatment, thus we investigated the effects of ABs derived from MSCs on periodontitis. MSCs were derived from bone marrows of mice and were cultured under hypoxic conditions for 72 h, after which ABs were isolated from the culture supernatant using a multi-filtration system. The results demonstrate that ABs derived from MSCs inhibited osteoclast differentiation and alveolar bone resorption. miRNA array analysis showed that miR-223-3p is highly enriched in those ABs and is critical for their therapeutic effects. Targetscan and luciferase activity results confirmed that Itgb1 is targeted by miR-223-3p, which interferes with the function of osteoclasts. Additionally, DC-STAMP is a key regulator that mediates membrane infusion. ABs and pre-osteoclasts expressed high levels of DC-STAMP on their membranes, which mediates the engulfment of ABs by pre-osteoclasts. ABs with knock-down of DC-STAMP failed to be engulfed by pre-osteoclasts. Collectively, MSC-derived ABs are targeted to be engulfed by pre-osteoclasts via DC-STAMP, which rescued alveolar bone loss by transferring miR-223-3p to osteoclasts, which in turn led to the attenuation of their differentiation and bone resorption. These results suggest that MSC-derived ABs are promising therapeutic agents for the treatment of periodontitis.