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Dental implants are commonly used to repair missing teeth. The implant surface plays a critical role in promoting osseointegration and implant success. However, little information is available about which implant surface treatment technology best promotes osseointegration and implant stability. The aim of this network meta-analysis was to evaluate the osseointegration and stability of four commonly used dental implants (SLA, SLActive, TiUnite, and Osseotite). The protocol of the current meta-analysis is registered in PROSPERO (International Prospective Register of Systematic Reviews) under the code CRD42020190907 (https://www.crd.york.ac.uk). We conducted a systematic review following PRISMA and Cochrane Recommendations. Medline (PubMed), Cochrane Library, Embase, and the Web of Science databases were searched. Only randomized controlled trials were considered. Twelve studies were included in the current network meta-analysis, eleven studies were included concerning the osseointegration effect and five studies were included for stability analysis (four studies were used to assess both stability and osseointegration). Rank possibility shows that the SLActive surface best promoted bone formation at an early healing stage and TiUnite seemed to be the best surface for overall osseointegration. For stability, TiUnite seemed to be the best surface. The present network meta-analysis showed that the SLActive surface has the potential to promote osseointegration at an early stage. The TiUnite surface had the best effect on osseointegration regarding the overall healing period. The TiUnite surface also had the best effect in stability.

Respiratory diseases, including pulmonary fibrosis, silicosis, and allergic pneumonia, can be caused by long-term exposure to dental prosthesis grinding dust. The extent of the toxicity and pathogenicity of exposure to PMMA dust, Vitallium dust, and dentin porcelain dust differs. The dust from grinding dental prosthesis made of these three materials was characterized in terms of morphology, particle size, and elemental composition. The adverse effects of different concentrations of grinding dust (50, 150, 300, 450, and 600 μg ml −l) on RAW264.7 macrophages were evaluated, including changes in cell morphology and the production of lactate dehydrogenase (LDH) and reactive oxygen species (ROS). The dust particles released by grinding dental prosthesis made of these materials had different morphologies, particle sizes, and elemental compositions. They also induced varying degrees of cytotoxicity in RAW264.7 macrophages. A possible cytotoxicity mechanism is the induction of lipid peroxidation and plasma membrane damage as the dust particles penetrate cells. Therefore, clinicians who regularly work with these materials should wear the appropriate personal protection equipment to minimize exposure and reduce the health risks caused by these particulates. Dental prostheses are made and tested, a variety of dust particles are emitted from the grinding performed to correct defects 1-4. Commonly used prosthetic materials include PMMA, Vitallium, and porcelain, and the dust created from grinding them may pose various health hazards to oral care workers, such as pulmonary fibrosis, silicosis, allergic pneumonia, lung granuloma, asthma, and lung cancer 5-8. Epidemiological investigations indicated that the effects of dental prosthesis grinding dust on the respiratory system of oral care workers may be correlated with dust exposure time and the type of dust. In addition, many studies have reported that the type of abrasive dust is closely related to specific respiratory diseases of oral care workers 9-13. Zhang et al. reported that animals were subjected to mixed dust types generated from grinding dental prostheses (PMMA, Vitallium and porcelain dust, etc.), and then, the histopathology of their lung tissue was examined. It was proposed that grinding dust induced fibrosis in rat lung tissue 14. Upadhyay et al. found that rats exposed to three different quality levels of fine dust (including 250, 500 and 1,000 μg ml −l) presented with increases in the total number of inflammatory cells and levels of interleukin-6 15. RAW264.7 cells are mouse mononuclear macrophage leukaemia cells that play key roles in inflammation, immunity and phagocytosis. They are readily available and their use raises fewer ethical issues than using human macrophages. The macrophage pneumoconiosis model is a currently established model 16. Various particles produce similar results. When calcium carbonate, silica dust, etc., are applied to cells, reactive oxygen species (ROS) and lactate dehydrogenase (LDH) are commonly measured as indicators of cytotoxicity...

Bone growth and metabolism are mainly regulated by a series of intracellular molecules and extracellular stimuli. Exosome, as a nanoscale substance secreted to the outside of the cells, plays an extensive role in intercellular communication. This review provides theoretical references and evidences for further exploration of exosomes as noncoding RNA carriers to regulate bone tissue recovery through the following aspects: (1) basic characteristics of exosomes, (2) research progress of exosomal noncoding RNA in bone tissue engineering, (3) current status and advantages of engineering exosomes as nanocarriers for noncoding RNA delivery, and (4) problems and application prospects of exosome therapy in the field of orthopedics.

Nano-hydroxyapatite/collagen (nHAC) is a new type of bone tissue engineering scaffold material. To speed up the new bone formation of nHAC, this study used concentrated growth factor (CGF) and nHAC in combination to repair rabbit mandibular defects. nHAC/CGF and nHAC were implanted into rabbit mandibles, and X-ray, Micro-CT, HE and Masson staining, immunohistochemical staining and biomechanical testing were performed at 8, 16 and 24 weeks after surgery. The results showed that as the material degraded, the rate of new bone formation in the nHAC/CGF group was better than that in the nHAC group. The results of the HE and Masson staining showed that the bone continuity or maturity of the nHAC/CGF group was better than that of the nHAC group. Immunohistochemical staining showed that OCN expression gradually increased with time. The nHAC/CGF group showed significantly higher BMP2 than the nHAC group at 8 weeks and the difference gradually decreased with time. The biomechanical test showed that the compressive strength and elastic modulus of the nHAC/CGF group were higher than those of the nHAC group. The results suggest that nHAC/CGF materials can promote new bone formation, providing new ideas for the application of bone tissue engineering scaffold materials in oral clinics.