[Application and exploration of artificial intelligence for caries management]

With the advent of big data era and improvement of computer performance, the artificial intelligence (AI) technology has rapidly boosted in the field of stomatology. Dental caries is one of the cutting-edge research domains in stomatology. The application of AI in dental caries is expected to promote intelligent, precise and high-efficient diagnosis and treatment of caries. This article focuses on the application of AI in medical-aided diagnosis, treatment and risk prediction of caries and discusses their challenges.

[Research progress in the pathogenesis mechanism of dental fluorosis]

Dental fluorosis is a developmental disturbance of dental enamel caused by excessive fluoride intake during tooth development, leading to the changes in morphology, structure and function of tooth enamel, which can affect the aesthetics and function of teeth. There are many factors which may account for the occurrence of dental fluorosis. However, the pathogenesis mechanism underlying dental fluorosis has not been fully clarified.In recent years, researches in the fields of fluoride-induced stress response pathways, signaling pathways and apoptosis at the molecular and genetic level had provided extensive knowledge of dental fluorosis. This article focuses on the latest research progress in the mechanism of dental fluorosis, which include the effects of fluoride on ameloblasts and enamel matrix proteins, genetic polymorphism and dietary nutrients, in order to provide new references for the targeted prevention and treatment of dental fluorosis.

[Application and prospect of static/dynamic guided endodontics for managing pulpal and periapical diseases]

Root canal therapy and endodontic surgery are conventional treatments for pulpal and periapical diseases. Compared with naked-eye operations, the application of dental operating microscope has enhanced the procedural accuracy and prognosis efficiently. However, root canals with pulp calcification/obliteration, apical lesions with thick cortical bone or adjacent to important anatomic structures are even challenging for experienced operators to achieve predictable clinical outcomes. Recently, with the advances in the field of digitalized information sciences, the above mentioned complicated endodontic cases can be solved under static and dynamic guidance. Before the treatment begins, virtual path is designed from data collected by cone-beam CT and oral image scanning using guidance software. Afterwards, root canal therapy and endodontic surgery can be performed precisely under the assistance of three-dimensional printed guide or dynamic guidance system. The present review describes the classification, features and clinical applications of the guided endodontics.

[Development strategies and progress of composite resin filling material]

Composite resin filling material is the first choice for tooth direct bonding restoration. Its good performance can meet the requirements of clinical tooth repair treatment. It is used to restore the structure, aesthetic and function of defected teeth with a way of minimally invasive intervention. To further improve its clinical efficacy, the fundamental strategy is to ameliorate the limitation of material properties. Based on the summary of current research progress, this article focuses on the property of improved composite resin material, and the progress of developing novel resin material including antibacterial composite resin, bioactive remineralizing resin as well as self-healing resin, so as to provide innovative ideas for the future research of new composite resin filling materials.

[Etiology, diagnosis, prevention and treatment of dental fluorosis]

Dental fluorosis is the most common and prominent symptom in the early stage of chronic fluorosis, which is caused by excessive fluorine intake during tooth development. In severe cases, it may be accompanied by skeletal fluorosis. There are also systemic damages to the nervous system, cardiovascular system, endocrine system and so on. The pathogenesis of dental fluorosis is not totally clear, which may be a complex pathological process involving both genetic and environmental factors. The prevalence of dental fluorosis has an upward trend arround the world, thus certain public prevention and treatment strategies need to be taken. This article focuses on the prevalence, etiology, diagnosis and scoring system, as well as the public prevention and treatment strategies, of dental fluorosis, so that to provide reference for the research and prevention of the disease.

[Formulation of guidelines for microscopic endodontics suitable for the situation of China]

In order to promote the use of dental operating microscope in endodontics, Society of Cariology and Endodontology of Chinese Stomatological Association formulated these guidelines, after extensive consultation with related authorities and careful reference to the available published materials and literatures. It is hoped that these guidelines will be useful for dental practitioners embarking on microscopic endodontics.

[Overall digitalization: leading innovation of endodontics in big data era]

In big data era, digital technologies bring great challenges and opportunities to modern stomatology. The applications of digital technologies, such as cone-beam CT(CBCT), computer aided design,(CAD)and computer aided manufacture(CAM), 3D printing and digital approaches for education , provide new concepts and patterns to the treatment and study of endodontic diseases. This review provides an overview of the application and prospect of commonly used digital technologies in the development of endodontics.

[Preliminary clinical study of endodontic antiseptic in monotithic type chlorhexidine controlled release delivery system]

The purpose of clinical study was to assess the bacteriological status of the root canal after disinfection with the monotithic type chlorhexidine enrolled release delivery system (CCROS).In experiments the monotithic type CCRDS was found to be more effective than the reservoir type CCRDS.The root canals of 24 teeth with apical periodontitis were completely instrumented and irrigated with sodium hypochloride.After the instrumentations,12 teeth were treated with the monotitihic type CCRDS,12 teeth were treated with formocresol.Bacterological samples from the root canals were taken after 5 days using an anaerobic technique.The results indicated that monotithic type CCRDS was more effective than formocresol in obtaining bacteria-free root canals(Chi-square test P<0.05).The advantages of an antiseptic with along lasting effect for the elimination of bacteria form the root canal and for the prevention of reinfection were emphasized.

[Experimental study on the interaction of fibronectin with oral Streptococci]

Interaction of fibronectin (Fn) with Streptococcus mutans, S. sorbrinus, and S. milleri is demonstrated by an enzyme-linked immunosorbent assay (ELISA). The results show that the three strains are able to adhere to Fn. The interaction may be strengthened while the concentration of Fn increases (q test P < 0.01). The ability of adherence among S. mutans, S. sorbrinus and S. milleri is different in Fn high concentration (q test P < 0.01). It is speculated the free Fn in saliva may serve as an agglution for elimination of the organisms from the oral cavity, or as a receptor when immobilized on the tooth surface for cariogenic streptococci to form plaque. A balance between these two functions of Fn may play a role in modulating the microbial ecological environment of the oral cavity.

[Detection of DNA G+C mol% in taxonomy of Streptococcus mutans by means of high performance liquid chromatography]

In the present study, DNA G+C mol% of 9 strains of bacteria (including 7 international standard strain, Ingbritt, and 2 other strains extracted in our Lab) were detected with application of High Performance Liquid Chromatograph. The results showed that DNA G+C content of S. mutans was 35-40%, S. sobrinus was 45-46%, S. cricetus was 38%, and S. rattus was 41%. The difference between S sobrinus and S. mutans was higher than 5%, which suggested that S. sobrinus should be identified as an independent classification unit of bacterial species from S. mutans.

[A study on resorbable local metronidazol delivery devices]

A local metronidazol (MTZ) delivery using resorbable base material was studied. In vitro MTZ was almost completely released within 24 hrs from the hydroxypropylmethyl cellullouse(HPMC) strips.In vivo,release of the drug strips was also measured in six patients who had deep pockets of more than 5mm.MTZ-containing HPMC strip was inserted in the pocket.The average amount of MTZ in the gingival crevicalar fluid(GCF) 24 hrs after insertion of strip was 40microg/ml.(much higher than the reported MIC of some microorganisms associated with adult periodontitis).In vitro there were significant inhibitory effects of MTZ containing strips on the microorganisms associated with periodontal disease.The prevalence of spirochetes and motil rods,and gingival index(GI) was remarkably reduced in the MTZ administered pockets,It is suggest that this new direct drug delivery system with HPMC used as base material could be used to treat periodontal disease.