2015年 · 第50卷第06期

Dental pulp can not only provide nutrition for teeth, but also make teeth feel the stimulation of the environment. The reaction of dental pulp and dentin regeneration can block the invasion of external pathogens. The health of dental pulp is related to the survival rate of teeth. With the progress of medicine, the demand for medical treatment is no longer limited to treating diseases and alleviating symptoms, but also to preserve and reconstruct natural human tissues and maintain their normal functions. From the point of view of dental treatment, people hope that dental treatment can have a better prognosis to preserve more natural dentition, and at the same time, the requirements for tooth aesthetics are also increased accordingly. When the pulp or tissue around the root causes disease of the pulp and surrounding tissue due to caries, fracture or other factors, it is necessary to preserve the function of the tooth and pulp by root canal treatment or vital pulp therapy. The advent of the era of minimally invasive dental medicine has improved the shortcomings of traditional pulp vitalization treatment. Seeking new pulp vitalization treatment materials and treatment concepts with high success rate and low trauma will become one of the development trends of dental medicine in the future. Due to the progress of tissue regeneration concept and the development of biomedical materials, bioactive materials such as calcium-silicon ceramics have good application prospects in the preservation and treatment of living pulp because of their good biocompatibility and the ability to induce calcified tissue formation. This paper reviews the application and improvement of biomedical materials for the preservation and treatment of living pulp, and discusses the role of biomedical materials in the preservation and treatment of living pulp by taking calcium and silicon materials as an example.

Caries is still the most prevalent oral disease, and its occurrence and development are inseparable from the formation of dental plaque biofilm. Streptococcus mutans is recognized as a major cariogenic bacterium, which can use sucrose to produce a large amount of viscous exopolysaccharide matrix, realize adhesion and aggregation on the tooth surface, and form plaque biofilm; At the same time, it rapidly metabolizes a variety of sugars to produce acid, which demineralizes the dental tissue and forms dental caries. As one of the normal bacterial flora of oral cavity, Streptococcus mutans is different from the general external invasive pathogenic bacteria. Its acid-producing and caries-causing ability depends on its adaptability to the adverse environmental factors of oral cavity and the synergistic or antagonistic effect of symbiotic bacterial flora in the micro-ecological environment of dental plaque, that is, the micro-ecological balance of plaque biofilm. When the ecological balance within the plaque biofilm is imbalanced, the pathogenicity of Streptococcus mutans is enhanced, leading to caries^[1]。 Streptococcus mutans can spontaneously form a competent state during growth, that is, a state in which it can take up and integrate exogenous free DNA. The ingested exogenous DNA fragments are integrated into the corresponding parts of bacterial chromosomes through homologous recombination, resulting in gene mutation in this part, thus changing bacterial virulence, drug resistance and some biological traits, and can be inherited stably, that is, natural transformation occurs^[2,3,4,5]。 The formation of Streptococcus mutans competence can promote the evolution of virulence factors such as biofilm formation and the acquisition of drug resistance genes, which is closely related to the cariogenic ability and drug resistance of bacteria. Current studies have shown that two component system (TCS), ABC efflux pump system (ATP-binding cassettes transporters) and MecA protein play important regulatory roles in the formation of S. mutans competence.

Sponsored by the Professional Committee of Dental Endodontics of Chinese Stomatological Association and hosted by the Affiliated Stomatological Hospital of Guanghua School of Stomatology of Sun Yat-sen University, the Ninth National Academic Conference on Dental Endodontics was held in Guangdong Building, Guangzhou from September 17 to 19, 2014. At the same time, the conference also held the re-election meeting of the professional committee of dental endodontics of the Chinese Stomatological Association. Professor Ling Junqi of Stomatological Hospital Affiliated to Guanghua School of Stomatology of Sun Yat-sen University was elected as the chairman of the 5th Dental Endodontics Professional Committee of Chinese Stomatological Association, Professor Bian Zhuan of School of Stomatology of Wuhan University was the chairman-designate, Professor Zhou Xuedong of West China School of Stomatology of Sichuan University, Professor Liang Jingping of School of Stomatology of the Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Professor Yue Lin of School of Stomatology of Peking University and Professor Yu Qing of School of Stomatology of the Fourth Military Medical University were the vice-chairmen.

adipose derived stem cells (ADSCs), a kind of adult mesenchymal stem cells with multidirectional differentiation potential, have been found in adipose matrix, which differentiate into osteogenesis, cartilage, fat and muscle in vitro^[1]。 Adipose stem cells are widely distributed in vivo, simple to isolate and culture, and have stronger expansion ability than bone marrow derived mesenchymal stem cells (BMSC) and have no obvious dependence on serum batch number. Therefore, ADSC has more important clinical application value. This study was reviewed and approved by the Medical Ethics Committee of Harbin Fifth Hospital (approval number: Harbin Fifth Hospital Ethics Committee No. 1, 2012). ADSC was used as seed cell induction to construct tissue engineered bone to repair maxillary defects and implant dentures, which are reported below.