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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.

Peri-implant disease, an important group of diseases that cause implant failure, are associated with metabolic abnormality. Metabolic syndrome (MetS) is a common metabolic disorder comprising abdominal obesity, hyperglycemia, systemic hypertension and atherogenic dyslipidemia. Previous studies had reported that MetS and its diversified clinical manifestations might be associated with peri-implant diseases, but the relationship and underlying mechanisms were unclear. This review aims to explore the relationship between MetS and peri-implant disease, in order to provide beneficial reference for the prevention and treatment of peri-implant disease in patients with MetS.

Objective: To evaluate the application effect of smart classroom teaching mode in undergraduate teaching of endodontics. Methods: Through micro-lecture and massive open online course which were closely integrated with clinical practice and frontier advances, we build a new smart classroom teaching mode of endodontics relying on information technology such as the medical education cloud APP platform. The mode was applied to the undergraduate teaching of grade 2017 (110 students) and grade 2018 (107 students) in 2020 and 2021 respectively (experimental group). The theoretical examination was conducted for the grade 2016 (control group, 111 students applied traditional teaching methods) in 2019, and for two experimental grades in 2020 and 2021 respectively. A questionnaire survey was conducted for the 2018 undergraduates to investigate the experience of the smart classroom teaching mode, and the application effect of the smart classroom teaching mode was evaluated by comparing the offline theoretical test scores of grades 2016, 2017 and 2018. Results: The results of the questionnaire showed that students in grade 2018 recognized the overall form of smart classroom teaching mode, and 75.2% (79/105) of the students satisfied with the teaching process, considering that it could enhance learning interest and enthusiasm, improve self-learning ability, facilitate the understanding and memory of knowledge points, as well as increase the extension and expansion of professional knowledge. Thirty-seven point one percent (39/105) of the students thought that smart classroom teaching mode was not conducive to the interaction between teachers and students and couldn't improve learning efficiency. Comparing the final theoretical examination scores of students in three years, it was found that the average scores of 2021 (78.79±9.88) and 2020 (76.45±8.33) were significantly higher than that of 2019 (67.67±10.58) ( t= 6.77, P< 0.001; t= 8.51, P< 0.001). The average score in 2021 was higher than that in 2020, although the difference was not significant ( t= 1.79, P= 0.223). Conclusions: The application of smart classroom mode improved the teaching effect of endodontics, which is worthy of further promotion to provide a positive reference in improving the educating effects of oral medicine.

Root canal obturation is conducted by using filling materials to tightly seal the root canal system after the procedure of preparation in order to control infection and promote periapical healing. The quality of root canal obturation is one of the essential factors affecting the prognosis of root canal treatment. Qualified root canal filling is defined as a homogeneous radiographic apical filling within the cemento-dentine junction with neither overfilling nor underfilling. This review elucidates the long-term outcome of root canal overfilling and its causes, the influence of apical overfilling on adjacent structures and the prevention and management of overfilling, so as to help the clinicians achieving a better outcome of root canal treatment and obtaining an optimal long-term prognosis.

The mRNA for the lysosomal proteinases cathepsins B, D, H, L, and S are broadly distributed in normal rodent tissues. Although total cathepsin mRNA levels generally parallel the protein catabolic activity of the tissues, the expressions of the individual enzymes do not appear to be linked. Thus, the relative proportions of the individual messages are found to vary from tissue to tissue. Further evidence for the independent regulation of lysosomal proteinase expression is derived from observations of selective increases in mRNA levels for individual proteinases in rodent tumors. Only cathepsin B mRNA is elevated in a highly metastatic murine B16a melanoma and in a Walker-256 rat carcinosarcoma, while Moloney murine sarcoma virus-transformed fibroblasts express increased mRNA for cathepsins B, D, and L and normal levels for H and S. To address the regulation of cathepsin B expression, the mouse cathepsin B gene and its 5'-upstream region were cloned. The gene has 10 exons and 9 introns spanning about 20 kilobases. The 5'-upstream region and exon 1 are GC-rich with several potential Sp1 binding sites. TATA and CAAT motifs adjacent to the transcription start site are not evident. These properties are characteristic of mammalian "housekeeping" genes. B16 melanoma cells contain three cathepsin B transcripts of 2.2, 4.0 and 5.0 kilobases. The two larger messages, which were not found in normal tissues, contain unusually long 3'-untranslated regions resulting from the alternative cleavage and polyadenylation of the 3' end of the cathepsin B pre-mRNA in B16 melanomas. As all three messages encoded normal preprocathepsin B, cathepsin B secretion by melanoma cells is probably due to posttranslational mechanisms and not to alternative splicing or gene mutation.

BALB/3T3 fibroblasts (3T3) were observed to secrete latent, pepsin-activatable forms of cathepsin B and cathepsin L as well as an active form of beta-glucuronidase when cultured in the absence of serum. The secretion of these proteins was stimulated by the cation ionophore monensin: cathepsin B, 4.3-fold; cathepsin L, 7.2-fold; and beta-glucuronidase, 3.1-fold. These increases were accompanied by a 50% decline in cellular levels of the active forms of these enzymes and by the cellular accumulation of latent forms of cathepsin B and cathepsin L. Latent forms of beta-glucuronidase were not detected. In contrast, Moloney murine sarcoma virus-transformed BALB/3T3 fibroblasts (MMSV) secreted greatly increased amounts of latent cathepsin B (17-fold) and latent cathepsin L (27-fold), and moderately increased amounts of active beta-glucuronidase (2-fold) in a manner which was not further increased by monensin. The increased monensin-insensitive secretion of these lysosomal enzymes by MMSV cells may be due to a transformation-induced decrease in mannose 6-phosphate receptors. Thus, 3T3 cells bound the neoglycoconjugate pentamannosyl 6-phosphate-bovine serum albumin at 4 degrees C in a pentamannosyl 6 phosphate and mannose 6-phosphate-inhibitable manner, whereas MMSV cells showed no measurable cell surface mannose 6-phosphate receptor binding activity.

This paper deals with the prospective clinical study on treatment of acute upper digestive tract hemorrhage with Wen-She decoction (WSD). An opened sequential controlled trial method of simple orientation quality reaction was adopted in this study. 7 cases were treated and all of them were cured. It was concluded that WSD was an excellent therapy to treat the middle or small amount hemorrhage of acute upper digestive tract. The effective rate of WSD of the stool OB (+) becoming (-) within 5 days was more than 95%. WSD consists of Codonopsis pilosulae, Atractylodes macrocephala, Poria cocos, Glycyrrhiza uralensis, Zingiber officinale, Os sepiae Halloysitum rubrum and Astragalus membranaceus. It is effective in stopping bleeding by warming the Spleen and tonifying Qi.