As a preliminary study for the precise three-dimensional (3D) modeling of teeth and alveolar sockets from cone-beam computed tomography (CBCT) images, the validity of the concept that a single voxel can simultaneously belong to two adjacent teeth was verified. A segmentation method based on a region-growing algorithm was developed, and 3D models of the first and second premolars were created from CBCT images of a human dry skull. A comparison of the resulting 3D models with actual measurements demonstrated sufficient accuracy for both the mesiodistal and buccolingual diameters, supporting the validity of the duplicate voxel concept.

Periodontitis, the sixth most prevalent global disease, causes tooth loss and systemic disorders, imposing a significant global burden. Functional regeneration of the periodontium remains a major challenge due to the hierarchical soft-hard tissue interface and complex spatiotemporal functional demands. In this study, a synchronously in situ co-injectable, interlayer-bonding, and wet-adhesive bilayer hydrogel (Bio-Fun bilayer) consisting of PCAC and PCMC layers is developed. An anti-delamination interface is engineered via polymer chain topological entanglement and dynamic boronate ester and ionic networks, while precise complex viscosity matching enables synchronized microscale laminar co-extrusion. Concurrently, the hydrogel maintains wet adhesion, especially to moist root and bone surfaces. Spatiotemporal biofunctionalization is achieved by loading microRNA-26a liposomes in the PCAC layer to activate Wnt/β-catenin signaling for osteogenesis, and covalently tethering a PDGF-BB mimetic peptide within the PCMC layer to trigger PI3K/Akt-LOX signaling for fibroblast recruitment and functional collagen formation. In vivo, the Bio-Fun bilayer hydrogel achieves integrated regeneration of alveolar bone and aligned periodontal ligament fibers, forming Sharpey's fiber-like structures with firm bone-ligament attachment. Meanwhile, the modular and injectable design might provide broad reference for the reconstruction of periodontal, osteochondral, and other soft-hard tissue interfaces.

Bacterial small RNAs (sRNAs) functions as post-transcriptional regulators that influnce microbial adaptation, pathobiont behavior, and host-microbe communication. This review analyzes bacterial sRNAs and vesicle-associated RNA signals in inflammatory and osteoimmune diseases, with a focus on gastrointestinal and oral microbial communities. Major sRNA classes and mechanisms are summarized, followed by an evaluation of evidence in gastrointestinal inflammation, periodontitis, rheumatoid arthritis, osteoarthritis, and postmenopausal osteoporosis. Direct disease-related evidence is currently limited. The most robust mechanistic example is Porphyromonas gingivalis vesicle-associated sRNA45033, which targets the 3' untranslated region (UTR) of CBX5 and regulates apoptosis in periodontal ligament cell, P. gingivalis outer membrane vesicles also promote alveolar bone resorption in vivo. Human studies in rheumatoid arthritis provide emerging associative evidence, while evidence in osteoarthritis and osteoporosis remains primarily indirect. Future research integrating small RNA sequencing, metatranscriptomics, extracellular vesicle profiling, and functional validation is required to establish causal roles and biomarker potential.

Guided tissue regeneration (GTR) is the core therapeutic strategy for repairing periodontal hard and soft tissue defects induced by periodontitis. Nevertheless, most current barrier membranes focus solely on alveolar bone reconstruction while ignoring the precise remodeling of the ordered periodontal ligament (PDL) microstructure, which impedes the integrated regeneration of functional periodontal tissues. To overcome these limitations, this study fabricated a novel bilayer composite GTR membrane with differentiated structural designs via sequential electrospinning for the synergistic and biomimetic regeneration of periodontal hard and soft tissues. The functionally graded membrane consisted of a dense, oriented poly-(lactic-co-glycolic acid) (PLGA) nanofiber outer layer and a porous collagen inner layer incorporated with hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) biphasic nanoparticles. The collagen matrix containing 60% HA and 40% β-TCP exhibited favorable mechanical properties that satisfy the mechanical requirements for periodontal repair. The dense PLGA layer effectively blocked the infiltration of human gingival fibroblasts (HGFs), and its physical barrier property could separate the external epithelial and connective tissues from the underlying bone tissue, offering a promising basis for the remodeling of periodontal hard and soft tissue. The inner Col/60% HA/40% β-TCP composite mimicked the natural organic-inorganic bone microenvironment and markedly promoted the adhesion, proliferation, and osteogenic differentiation of bone marrow mesenchymal stem cells. The distinctive fibrous topography of the electrospun bilayer membrane provides contact guidance at the defect margins, facilitating the ordered regeneration and rearrangement of the periodontal ligament. In vivo rat periodontal defect experiments demonstrated that the bilayer membrane, compared with single-component membranes and commercial Bio-Gide membranes, significantly enhanced new bone formation and promoted the regeneration of ordered PDL-like fibrous structures with an orientation angle approaching that of the native periodontal ligament, achieving synchronized biomimetic regeneration of periodontal hard and soft tissues. In conclusion, this bilayer GTR membrane addresses the limited PDL reconstruction achieved by conventional barrier materials and provides a promising strategy for the targeted repair of complex periodontal defects.

Periodontal and alveolar bone regeneration requires coordinated angiogenic and osteogenic responses supported by biomimetic scaffolds. This study compared three-dimensional bioprinted hydroxyapatite-acrylated palm olein (3D-HA-APO) scaffold formulations containing 5%, 7% and 10% (w/v) hydroxyapatite (HA), designated F1, F2 and F3, respectively. Human umbilical vein endothelial cells were cultured on the scaffolds, and background-corrected soluble vascular endothelial growth factor (VEGF) concentrations in culture supernatants were quantified by enzyme-linked immunosorbent assay (ELISA). Angiogenic-related responses of human periodontal ligament stem cells were assessed by VEGF and cluster of differentiation 31 (CD31) immunofluorescence after endothelial induction, while alkaline phosphatase (ALP) activity in construct lysates was used as an indicator of early osteogenic activity. Soluble VEGF concentrations increased from F1 to F3, with significant differences between all formulations. VEGF-associated signal proportions differed among formulations, with F3 significantly higher than F1. CD31-associated signal proportions increased progressively from F1 to F3, with significant differences between all formulation pairs. ALP activity increased over time in all scaffold groups, and F3 generally showed the highest activity from Day 4 onwards. Overall, F3 showed the most favourable formulation-level profile across the selected angiogenic-related and early osteogenic outcomes.

The tooth socket healing model (TSHM) is a widely used animal model for investigating the molecular mechanisms underlying bone regeneration. Although the murine mandibular TSHM is valuable for studying mandibular-specific pathological processes, establishing this model remains technically challenging because of the anatomical and biomechanical characteristics of the mandibular molar region. This protocol describes a modified approach for mandibular first molar extraction in mice and compares its performance with the conventional technique to improve procedural efficiency and reproducibility. Under controlled experimental conditions, the modified approach significantly reduced the average extraction time from 29 to 10 min. In addition, the modified group exhibited fewer extraction-related complications, including root and alveolar bone fractures, indicating improved procedural consistency. Micro-computed tomography (μCT) analysis further demonstrated improved preservation of extraction socket architecture during early healing. These findings indicate that the modified extraction approach improves procedural efficiency and reproducibility while reducing the technical challenges associated with murine mandibular tooth extraction. This protocol may facilitate more consistent establishment of murine mandibular tooth socket healing models, particularly for researchers with limited microsurgical experience.