BACKGROUND:With the development of computer-aided design and computer-aided manufacturing technology,zirconia abutments with a titanium base are widely used in clinic due to its good application advantages,but there are still some problems and a lack of consensus design standards. OBJECTIVE:To review the fabrication methods of Ti-base zirconia abutment,and the effect of abutment connection,emergence design,abutment angle,and bonding on mechanical properties of Ti-base zirconia abutment. METHODS:Relevant literature published from 2010 to 2023 was searched in CNKI and PubMed databases with the search terms"zirconia abutment,titanium base"in Chinese and English,respectively.The search time limit was extended for some classical literature.The relevant literature was obtained through inclusion and exclusion criteria,and 57 eligible documents were included for review. RESULTS AND CONCLUSION:It is recommended that clinicians try to select antirotational titanium bases or rotational titanium bases with a Morse taper connection.Implants should be placed in the correct axial angulation of not more than 15° or with an inclination to the palatal side when using angled zirconia abutments.When a≥30° labial inclination is followed for implant placement,the bite force must be decreased effectively to reduce the risk of mechanical and biological complications of implants,abutments,and prostheses.Ti-base zirconia abutments with a higher gingival height should be selected,and its restorative angle should not exceed 40°.Multilink Hybrid Abutment could be the first choice for extraoral bonding of zirconia abutment to titanium bases.

BACKGROUND:As an essential trace element for body growth and development,copper participates in many processes such as redox process,energy generation,signal transduction and bone metabolism.The imbalance of copper homeostasis in diabetic patients will lead to the increase of oxidative stress and the impairment of antioxidant mechanism,which stimulate the production of inflammatory mediators and inflammatory factors,and thus lead to cytotoxicity and body damage.In recent years,the role of copper in diabetes has gradually attracted attention,and some studies have confirmed that copper plays a key regulatory role in the pathological process of diabetes.OBJECTIVE:To summarize the current progress in the role of copper in systemic complications of diabetes and provide some theoretical reference for its future research and treatment.METHODS:The first author searched PubMed,Web of Science,CNKI and WanFang databases for literature related to the role of copper in systemic complications of diabetes.The search terms were"copper,Cu,diabetes,diabetic complications,diabetic cardiomyopathy,diabetic nephropathy,diabetic retinopathy,diabetic osteoporosis,diabetic periodontitis"in English and Chinese,respectively.After screening,95 articles were included in the review.RESULTS AND CONCLUSION:(1)Copper is involved in the occurrence and development of diabetic complications and most of the damage caused by copper to the body is due to interference with the body's redox level.(2)In diabetic cardiomyopathy,increased Cu2+in the corpuscular circulation and impaired uptake of copper ions by cardiomyocytes,the accumulation of redox-active Cu2+and ceruloplasmin outside the cardiomyocyte induces copper oxidative stress in cardiomyocytes,leading to acute cardiac impairment.(3)In diabetic nephropathy,the toxic effect of excessive copper leads cause granular degeneration and vacuolar degeneration of renal tubular epithelial cells and proximal tubular necrosis,eventually leading to chronic or acute renal failure.(4)Excessive copper in diabetic patients can produce reactive oxygen species and directly or indirectly affect the function of copper protein with antioxidant function,thus damaging retinal cells.(5)In patients with diabetic osteoporosis,accumulated copper induces lipid peroxidation and interferes with bone metabolism.Copper acts on osteoblasts mainly through inhibition of superoxide dismutase,glutathione peroxidase,and alkaline phosphatase activities.(6)Excessive copper exacerbates inflammatory changes in periodontal tissue by promoting inflammatory responses.

BACKGROUND:Copper is an essential trace element and plays a key role in series of physiological activities in the body.Metabolic disturbance of copper is closely associated with multiple diseases.Copper metabolism is mainly involved in the absorption,transport,storage and excretion of copper ions,and all the above processes regulate copper homeostasis in the body.In recent years,many studies have confirmed that copper homeostasis disorder severely affects the metabolic activities of the body and cause diseases in various systems.Besides,the role of copper in oral diseases has been of great interest.OBJECTIVE:To explore the role of copper in occurrence,development,and treatment of oral diseases,and provide a comprehensive overview of research advances in this field.METHODS:The first author searched relevant studies on copper in oral diseases using a computer in PubMed,Web of Science,and CNKI.The key words were"Cu,copper,copper metabolism,oral diseases,oral squamous cell carcinoma,periodontitis,oral submucous fibrosis,oral lichen planus,recurrent oral ulceration,pultitis"in English and Chinese.After screening,78 articles were included for further review and analysis.RESULTS AND CONCLUSION:(1)Patients with oral squamous cell carcinoma have elevated concentrations of copper in serum and saliva,and elevated copper promotes cancer progression through oxidative stress and promoting angiogenesis.Excessive elevation or reduction of copper concentration in tumor cells can inhibit the growth of tumor cells.The combination of copper and anticancer drugs can significantly improve the efficacy of drugs.(2)The concentration of copper in the serum of patients with periodontitis is increased,and excessive copper can aggravate periodontitis through promoting oxidative stress.Combination of copper and drugs can promote periodontal bone regeneration and periodontal tissue healing.(3)The level of copper is positively correlated with degree of oral mucosa fibrosis.Copper that enters the oral mucosa promotes fibrosis of oral mucosa by enhancing activity of lysyloxidase to increase production of collagen.(4)Copper levels are elevated in patients with oral lichen planus,and elevated copper may promote the progression of oral lichen planus by modulating immune cell function.(5)In patients with recurrent oral ulcers,serum copper level is significantly increased,and utilization of copper becomes disordered,which could decrease copper-containing enzyme activity,thus affecting the healing of ulcers.Copper is closely associated with multiple oral diseases and therapies targeting at copper could obviously enhance the therapeutic effect of drugs.But further studies are still needed to uncover its mechanisms to lay foundation for the better treatment of oral diseases.

BACKGROUND:As an essential trace element for body growth and development,copper participates in many processes such as redox process,energy generation,signal transduction and bone metabolism.The imbalance of copper homeostasis in diabetic patients will lead to the increase of oxidative stress and the impairment of antioxidant mechanism,which stimulate the production of inflammatory mediators and inflammatory factors,and thus lead to cytotoxicity and body damage.In recent years,the role of copper in diabetes has gradually attracted attention,and some studies have confirmed that copper plays a key regulatory role in the pathological process of diabetes.OBJECTIVE:To summarize the current progress in the role of copper in systemic complications of diabetes and provide some theoretical reference for its future research and treatment.METHODS:The first author searched PubMed,Web of Science,CNKI and WanFang databases for literature related to the role of copper in systemic complications of diabetes.The search terms were"copper,Cu,diabetes,diabetic complications,diabetic cardiomyopathy,diabetic nephropathy,diabetic retinopathy,diabetic osteoporosis,diabetic periodontitis"in English and Chinese,respectively.After screening,95 articles were included in the review.RESULTS AND CONCLUSION:(1)Copper is involved in the occurrence and development of diabetic complications and most of the damage caused by copper to the body is due to interference with the body's redox level.(2)In diabetic cardiomyopathy,increased Cu2+in the corpuscular circulation and impaired uptake of copper ions by cardiomyocytes,the accumulation of redox-active Cu2+and ceruloplasmin outside the cardiomyocyte induces copper oxidative stress in cardiomyocytes,leading to acute cardiac impairment.(3)In diabetic nephropathy,the toxic effect of excessive copper leads cause granular degeneration and vacuolar degeneration of renal tubular epithelial cells and proximal tubular necrosis,eventually leading to chronic or acute renal failure.(4)Excessive copper in diabetic patients can produce reactive oxygen species and directly or indirectly affect the function of copper protein with antioxidant function,thus damaging retinal cells.(5)In patients with diabetic osteoporosis,accumulated copper induces lipid peroxidation and interferes with bone metabolism.Copper acts on osteoblasts mainly through inhibition of superoxide dismutase,glutathione peroxidase,and alkaline phosphatase activities.(6)Excessive copper exacerbates inflammatory changes in periodontal tissue by promoting inflammatory responses.

BACKGROUND:Copper is an essential trace element and plays a key role in series of physiological activities in the body.Metabolic disturbance of copper is closely associated with multiple diseases.Copper metabolism is mainly involved in the absorption,transport,storage and excretion of copper ions,and all the above processes regulate copper homeostasis in the body.In recent years,many studies have confirmed that copper homeostasis disorder severely affects the metabolic activities of the body and cause diseases in various systems.Besides,the role of copper in oral diseases has been of great interest.OBJECTIVE:To explore the role of copper in occurrence,development,and treatment of oral diseases,and provide a comprehensive overview of research advances in this field.METHODS:The first author searched relevant studies on copper in oral diseases using a computer in PubMed,Web of Science,and CNKI.The key words were"Cu,copper,copper metabolism,oral diseases,oral squamous cell carcinoma,periodontitis,oral submucous fibrosis,oral lichen planus,recurrent oral ulceration,pultitis"in English and Chinese.After screening,78 articles were included for further review and analysis.RESULTS AND CONCLUSION:(1)Patients with oral squamous cell carcinoma have elevated concentrations of copper in serum and saliva,and elevated copper promotes cancer progression through oxidative stress and promoting angiogenesis.Excessive elevation or reduction of copper concentration in tumor cells can inhibit the growth of tumor cells.The combination of copper and anticancer drugs can significantly improve the efficacy of drugs.(2)The concentration of copper in the serum of patients with periodontitis is increased,and excessive copper can aggravate periodontitis through promoting oxidative stress.Combination of copper and drugs can promote periodontal bone regeneration and periodontal tissue healing.(3)The level of copper is positively correlated with degree of oral mucosa fibrosis.Copper that enters the oral mucosa promotes fibrosis of oral mucosa by enhancing activity of lysyloxidase to increase production of collagen.(4)Copper levels are elevated in patients with oral lichen planus,and elevated copper may promote the progression of oral lichen planus by modulating immune cell function.(5)In patients with recurrent oral ulcers,serum copper level is significantly increased,and utilization of copper becomes disordered,which could decrease copper-containing enzyme activity,thus affecting the healing of ulcers.Copper is closely associated with multiple oral diseases and therapies targeting at copper could obviously enhance the therapeutic effect of drugs.But further studies are still needed to uncover its mechanisms to lay foundation for the better treatment of oral diseases.

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".

This article starts with the definition of integrated curriculum, analyzes the modes of horizontal, vertical and spiral integration, and summarizes the implementation of integrated curriculum models in North America, Europe and Asian countries. At the same time, we present the implementation of the integrated curriculum teaching model in several domestic universities. Then, we analyze the problems of the domestic integrated curriculum from the aspects of mechanism structure, content connection, teaching ability and assessment and evaluation. Finally, we propose corresponding thoughts and suggestions for the problems from the learning theories view.