Background: Most patients with insufficient bone mass suffer from severe horizontal or vertical bone defects in oral implant surgery. The purpose of this study was to compare the bone regeneration effects of titanium meshes with different porosity in the treatment of bone defects.Methods: Nine beagle dogs were equally divided into three groups based on execution time. Three months after the extraction of the first to fourth premolars of the mandible, three bone defects were randomly made in the mandible. Bone particles and three kinds of three-dimensional (3D) printed titanium nets with different porosities (low porosity group (LP), 55%; medium porosity group (MP), 62%; and high porosity group (HP), 68%) were replanted in situ. The beagles were killed 4, 8, and 12 weeks after surgery. Formalin-fixed specimens were embedded in acrylic resin. The specimens were stained with micro-CT, basic fuchsin staining, and toluidine blue staining.Results: Micro-CT analysis showed that the trabecular thickness, trabecular number, and bone volume fraction of the HP group were higher than those of the other two groups. Moreover, the trabecular separation of the HP group decreased slightly and was lower than that of the MP and LP groups. Histological staining analysis showed that the trabecular number in the HP group was higher than in the other two groups at 8 and 12 weeks, and the bone volume fraction of the HP was higher than that in the other two groups at 12 weeks. Moreover, the trabecular thickness of the MP was higher than that of the LP group at 12 weeks and the trabecular separation was lower in the HP group at 4 and 8 weeks. The differences were statistically significant (p < 0.05).Conclusion: A 3D printed titanium mesh with HP in a certain range may have more advantages than a titanium mesh with LP in repairing large bone defects.

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Dental nurses are a high-risk group for occupational exposure, but how to reduce occupational exposure rates still faces challenges. This study aims to conduct a retrospective questionnaire survey with dental nurses from a tertiary A specialized dental hospital in Beijing as the main target to study the dental nursing population: 1) exposure events, including the types and times of occupational exposure, as well as the devices that cause occupational exposure; and 2) occupational expectations and attitudes toward patients with infectious diseases. This project aims to provide a theoretical basis for improving the safety awareness of dental nurses and reducing occupational exposure risks to a certain extent.

Fungiform papillae contain taste buds and play a critical role in mastication and the gustatory system. In this study, we report a series of sequential observations of organogenesis of fungiform papillae in miniature pigs, as well as changes in the expression of BMP2, BMP4, Wnt5a, Sox2, and Notch1 signaling pathway components. In this study, we investigated the spatiotemporal expression patterns of BMP, Wnt, Sox2 and Notch in the fungiform papillae of miniature pigs at the bud stage (E40), cap stage (E50) and bell stage (E60). Pregnant miniature pigs were obtained, and the samples were processed for histological staining. Immunohistochemistry and real-time PCR were used to detect the mRNA and protein expression levels of BMP2, BMP4, Wnt5a, Sox2, and Notch1. At E40, fungiform papillae were present on the anterior two-thirds of the tongue in a specific array and pattern. The fungiform papillae were enlarged and basically developed at E50 and were largest at the earlier stage (E60). Most of the BMP2 was concentrated in the epithelial layer and the connective tissue core of the fungal papilloma and gradually accumulated from E40-E60. BMP-4 was weakly expressed in the fungiform papillae epithelia, but BMP-4-positive cells were also observed in the developing tongue muscle at E50 and E60. Wnt5a-positive cells were observed in the fungiform papillae epithelia and developing tongue muscle at all three time points. Sox2-positive cells were observed only in fungiform papillae epithelial cells, and Notch1-positive cells could not be detected. This study provides primary data regarding the morphogenesis and expression of developmental signals in the fungiform papillae of miniature pigs, establishing a foundation for further research in both this model and humans.

Background Most patients with insufficient bone mass suffer from severe horizontal or vertical bone defects in oral implant surgery. The purpose of this study was to compare the bone regeneration effects of titanium mesh with different porosity in the treatment of bone defects. Methods Nine beagle dogs were equally divided into three groups. Three months after the extraction of the first to fourth premolars of the mandible, three bone defects were randomly selected in the mandible. Bone particles and three kinds of 3D printed titanium nets with different porosity (low porosity group, 55%; medium porosity group, 62%; and high porosity group, 68%) were replanted in situ. Beagle dogs were killed 4, 8, and 12 weeks after surgery. Formalin fixed specimens were embedded in acrylic resin. The specimens were stained with micro CT and hard tissue grinding. Results microCT analysis showed that the trabecular thickness, trabecular number, and bone volume fraction of the high porosity group were higher than those of the other two groups. Moreover, the trabecular separation of the high porosity group decreased slightly at any time and was lower than that of the medium porosity and low porosity groups. Histological staining analysis showed that the trabecular number in the high porosity group was higher than in the other two groups at 8 and 12 weeks, and the bone volume fraction was higher than that in the other two groups at 12 weeks. Moreover, the TB. Thmp was higher than that of the LP group at 12 weeks and the trabecular separation was lower in the high porosity group at 4 and 8 weeks. The differences were statistically significant (P < 0.05). Conclusions 3D printed titanium mesh with high porosity in a certain range may have more advantages than titanium mesh with low porosity in repairing large bone defects.