BACKGROUND: Bone marrow mesenchymal stem cells have good potential for directional differentiation, but the effect and mechanism of enamel matrix derivatives on osteogenic differentiation are still unclear. OBJECTIVE: To summarize the latest research progress on osteogenic induction of bone marrow mesenchymal stem cells by enamel matrix derivatives. METHODS: Related literature from 2000 to 2020 was searched in CNKI, Wanfang Data, VIP Database, PubMed databases. The key words are “Emdogain® or enamel matrix derivatives, bone marrow mesenchymal stem cells”. The languages of the literature were set to Chinese and English. When retrieving some classic articles, the publication date could be extended appropriately. Finally, 62 English articles and 5 Chinese articles meeting the inclusion criteria were selected. RESULTS AND CONCLUSION: There are different reports on the osteogenic effect of enamel matrix derivatives on bone marrow mesenchymal stem cells. Enamel matrix derivatives may enhance the osteogenic induction ability of bone marrow mesenchymal stem cells, and may enhance the osteogenic effect by affecting cells or cell membranes, but the relevant mechanism is unclear.

BACKGROUND:Periodontitis is an inflammatory and destructive disease with plaque biofilm as the main pathogenic material,which occurs in the gingiva,periodontal ligament,alveolar bone and cementum.The antigen of bacterial complex and its secreted toxin and enzyme directly lead to the destruction of periodontal tissue and trigger the host's immune response,causing indirect damage to the body tissue.Silence information regulatory factors(Sirtuins,SIRTs)play an important role in anti-aging,anti-oxidative stress,regulating inflammation,and mediating autophagy,and are closely related to the occurrence and development of periodontitis. OBJECTIVE:To review the research status of Sirtuins in periodontitis. METHODS:The first author used the computer to search the relevant research regarding the role of Sirtuins in periodontitis in PubMed,Web of Scene,CNKI and WanFang databases.The key words were"Sirtuins,Sirtuin1-7,periodontitis"in English and Chinese.After literature screening,57 articles were included for review and analysis. RESULTS AND CONCLUSION:SIRT1,SIRT2,SIRT3,and SIRT6 participate in regulating the occurrence and development of periodontitis.Inhibition of SIRT1 expression may be the target of periodontitis treatment,while overexpression of SIRT1 can inhibit periodontitis and protect periodontal tissue.The activator of SIRT1 can reduce the inflammation of periodontal tissue and improve the systemic pathological changes caused by periodontitis.SIRT2 is involved in nicotinamide phosphoribosyltransferase-mediated periodontal inflammation and plays a role in the treatment and prognosis of periodontal diseases.SIRT3 can improve age-related periodontal disease.Gastrodin promotes the osteogenic differentiation of periodontal ligament stem cells through the up-regulation of SIRT3.The activator of SIRT3 reduces the damage of periodontitis to periodontal and renal tissues by regulating the level of autophagy in the cells.SIRT6 can inhibit the inflammatory reaction of periodontal tissue and inhibit the differentiation and mineralization of cementoblasts.SIRT6 is beneficial to the prognosis of periapical periodontitis.The relationship between SIRT4,SIRT5,SIRT7 and periodontitis is rarely reported.

BACKGROUND:With the increasing demand for edentulous jaw restoration,"All-on-4"concept is widely used.The load transfer mode of implant is different from that of natural tooth.The three-dimensional finite element analysis can study the stress distribution of implants and surrounding bone tissues under functional loading.On this basis,it provides research methods for finding suitable implant materials,optimizing implant geometry,and designing clinical surgical protocols. OBJECTIVE:To review researches related to three-dimensional finite element analysis in"All-on-4"concept. METHODS:Relevant literature published from 2003 to 2023 was searched in CNKI and PubMed databases with the search terms of"finite element method;All-on-4;edentulous;biomechanics"in Chinese and English.Finally,65 articles were included for review. RESULTS AND CONCLUSION:(1)In the case of insufficient horizontal bone mass,we can choose to apply narrow diameter implants,but we need to pay attention to the effect of the presence of the cantilever on the stress distribution and reduce the risk of failure.(2)The"All-on-4"concept reduces the stress distribution of bone by tilting the distal middle implant,but the ideal angle of the distal implant tilt in different jaw types requires further study.(3)The presence of cantilevers increases the risk of implant failure,and keeping the cantilever length/AP distance ratio at 0.9 helps to minimize mechanical complications.(4)When a framework is made of a material with a lower elastic modulus,the stress on the framework itself will be smaller,but it will increase the stress on the implant,prosthetic screw,abutment and peri-implant bone.On the contrary,when a material with a higher elastic modulus is used,it can reduce the stress on the prosthetic components,implants and peri-implant bone in the restoration,but the stress on the framework itself is higher.(5)The"All-on-4"concept allows for a better mechanistic balance,but requires the development of a long-term,effective treatment program that is tailored to the patient's specific situation.(6)Proper occlusal scheme is the key to the success of implant treatment,and there is no difference between canine-guide occlusion and group function occlusion in terms of the longevity of the restoration.However,there are many factors that influence occlusal design,and further in vitro experiments as well as a number of clinical studies are needed to explore the ideal occlusal design of the"All-on-4".