Biomineralisation is a remarkable biological process in which living organisms exert precise control over the nucleation and growth of inorganic crystalline phases, resulting in the formation of hierarchically structured biocomposites that exhibit exceptional mechanical and functional properties. Since damage to bone and teeth directly affect everyday life, various biomimetic mineralised materials have been engineered for use in biomedical applications. While bioinspired materials typically demonstrate superior mechanical properties and biological functions, significant disparities remain between biomimetic constructs and their natural counterparts, especially concerning mechanical performance and multiscale structural organisation. This review initially describes the dynamic reciprocity between type I collagen fibrils, amorphous calcium phosphate phases and multifunctional non-collagenous protein within mineralisation microenvironments. Furthermore, it evaluates recent progress in advanced biomaterials based on biomimetic mineralisation strategies and seeks to spark innovative and promising solutions for investigators exploring biomineralisation principles in regenerative medicine and hard tissue reconstruction. Existing problems and future directions are discussed.
 
Keywords: biomineralisation, calcium phosphate, calcium, hard tissue regeneration, noncollagenous proteins

Objective: To investigate the biological function of miR-192-5p in osteogenic and odontogenic differentiation of dental pulp stem cells (DPSCs).
Methods: Alkaline phosphatase (ALP) activity assay, Alizarin Red S (ARS) staining and western blot analysis were applied to investigate the osteogenic differentiation potential of DPSCs in vitro. The osteogenic capacity was estimated by subcutaneous transplantation in nude mice in vivo. Carboxyfluorescein diacetate, succinimidyl ester (CFSE) assay was used to examine cell proliferation. Bioinformatics analyses, dual-luciferase reporter assays and real-time reverse transcriptase-polymerase chain reactions (RT-PCR) were applied to explore the regulatory mechanism of miR-192-5p.
Results: miR-192-5p decreased the ALP activity, nodule mineralisation and expression of BSP and OCN in DPSCs, and inhibited cell proliferation. Conversely, the miR-192-5p inhibitor motivated the osteogenic and odontogenic differentiation of DPSCs both in vitro and in vivo, along with promoting cell proliferation. COL5A1 was recognised as the target gene of miR-192-5p through bioinformatics analysis. Furthermore, dual luciferase reporter assays and RT-PCR experiments confirmed this interaction. Subsequent research verified that COL5A1 knockdown negatively affects the osteo-/odontogenic differentiation of DPSCs, with the PI3K/AKT signaling pathway involved in this process. COL5A1 knockdown promoted the proliferation of DPSCs.
Conclusion: miR-192-5p suppressed osteo/odontogenic differentiation by targeting COL5A1 in DPSCs and negatively regulated their proliferation. Conversely, COL5A1 knockdown promoted proliferation.
 
Keywords: cell proliferation, COL5A1, DPSCs, miR-192-5p, osteo-/odontogenic differentiation

Objective: To evaluate the precision and efficiency of dynamic navigation-assisted trephines and fissure drills at varying depths utilising a 3D printed model.
Methods: A computer-designed in vitro standardised model was 3D printed using photosensitive resin, with hemispherical cavities reserved at depths of 5, 10 and 15 mm from the outer surface of the model. CBCT scans were taken before the procedure, and the data were imported into dynamic navigation software. Navigation paths were planned and executed using a trephine with a diameter of 4 mm and a fissure drill with a diameter of 1.2 mm guided by the dynamic navigation system. Ten procedures were performed at each depth. Postoperative CBCT scans were taken to reconstruct the navigated trajectories, and the platform deviations, end deviations and angular deviations were calculated by comparing the actual paths with the planned paths. The operating time was recorded.
Results: Under the guidance of the dynamic navigation system, the mean platform, end and angular deviations for trephines were 0.34 ± 0.17 mm, 0.25 ± 0.15 mm and 1.02 ± 0.49 degrees, respectively. For fissure drills, the mean deviations were 0.29 ± 0.13 mm, 0.31 ± 0.18 mm, and 1.33 ± 0.98 degrees, respectively. No significant differences were found with different depths or instrument types (P > 0.05). High-speed handpieces with fissure drills showed superior efficiency to low-speed handpieces with trephines (P < 0.001).
Conclusion: Dynamic navigation technology achieved good accuracy within a 15-mm depth range. The use of a trephine or fissure drill did not affect the accuracy of the dynamic navigation technique. High-speed handpieces with fissure drills showed superior efficiency.
 
Keywords: CBCT, computer-assisted, dynamic navigation, 3D printing

The diagnosis of a facial sinus tract caused by periapical infection remains difficult due to the wide range of potential aetiologies. The canine is the only maxillary tooth that has been reported to serve as the source of infection for a facial sinus tract. The scenario encountered in the present case was extremely rare as the facial sinus tract was caused by the maxillary molar. The buccal alveolar bone of the maxillary right first molar had been destroyed due to periodontitis and aberrant occlusal force, which caused a periapical abscess in the maxillary right first molar site and ultimately drained extraorally. The purpose of this case report is to illustrate the potential for a periapical lesion of the maxillary molar to induce facial sinus tracts and propose a non-surgical therapeutic approach for such cases.
 
Keywords: facial sinus tract, maxillary first molar, non-surgical management, periapical infection