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Abstract Objective: To investigate the involvement of IL-6/STAT3 signaling pathway activation in macrophage polarization and bone destruction related to apical periodontitis (AP) stimulated by Porphyromonas gingivalis. Methodology: Macrophage polarization, IL-6/STAT3 expression, and the presence of P. gingivalis were detected in human AP tissues via RT-qPCR, western blotting, and immunohistochemistry staining. Murine bone marrow derived macrophages were isolated and cultured with P. gingivalis W83 in vitro, and levels of macrophage IL-6 expression, STAT3 phosphorylation, and macrophage polarization with or without the selective STAT3 phosphorylation inhibitor Stattic (5 μM) were detected via ELISA, western blotting, RT-qPCR, and flow cytometry, respectively. P. gingivalis-induced murine AP models were constructed, and bone destruction and macrophage polarization in the apical region were evaluated. Transwell co-culture systems were used to investigate the effects of macrophages infected with P. gingivalis on osteogenesis and osteoclastogenesis. Results: P. gingivalis was detected in human AP tissues that highly expressed IL-6/STAT3, and the M1 subtype of macrophages was more abundant in these tissues. P. gingivalis infection induced IL-6 expression, STAT3 phosphorylation, and M1 polarization of macrophages, while 5 μM of Stattic partially abolished these activation effects. Systemic STAT3 blockade via oral administration of Stattic at a dose of 25 mg kg-1 alleviated murine periapical bone resorption and apical infiltration of M1 macrophages induced by P. gingivalis infection in vivo. Furthermore, macrophages infected with P. gingivalis promoted bone destruction via secretion of IL-6, TNF-α, and RANKL, which hinder pre-osteoblast expression of Runx2 and accelerate pre-osteoclast expression of NFAT2. Conclusions: The activation of IL-6/STAT3 signaling pathway is involved in mediating macrophages M1 polarization in the P. gingivalis induced apical inflammatory context and may also be intimately involved in the bone loss caused by P. gingivalis infection, directing the M1 macrophage infiltration during the progression of AP.
ABSTRACT
@#Dental fluorosis is a kind of enamel hypoplasia caused by excessive fluorine intake during tooth development, leading to the formation of enamel with a lower mineral content and increased porosity, which can affect dental function and patients′ appearance. The prevalence of dental fluorosis remains high on a global level, and its occurrence is affected by many factors. Excessive fluorine intake is a major risk factor for dental fluorosis. The ways of fluorine intake mainly includes the application of fluorides, daily diet and air. Since fluorides have been widely used in the prevention of caries in recent decades and the methods of exposure to fluorine have been increasing, increasing numbers of studies have been conducted to explore how fluoride can achieve a balance between the effective prevention of caries and the prevention of dental fluorosis. In addition, exposure to fluorine at earlier ages can also increase the risk of dental fluorosis, while the improvement of nutritional structure can affect dental fluorosis prevention. Genetic susceptibility, socioeconomic status and parental awareness may influence dental fluorosis. This article aimed to review the latest research progress on the factors influencing dental fluorosis and provide a reference for the prevention and treatment of dental fluorosis.
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@#Caries is an important public health problem that affect the quality of life of residents, and microorganisms is the most important factor in its incidence. Probiotics are types of microorganisms that are beneficial to the human body and can regulate the microecological balance; thus, they have great potential for caries prevention. This paper reviews the caries prevention mechanism of probiotics, the research progress of probiotics of different genera, and the early colonization of probiotics and their safety. The literature review showed that probiotics aimed at caries prevention could colonize the oral cavity and played a role in caries prevention by inhibiting the growth of cariogenic bacteria and regulating host immunity. At present, probiotics used to prevent dental caries include probiotic Lactobacillus, Bifidobacterium and Streptococcus. The positive effect of probiotics on dental caries has been confirmed in most clinical trials. Because probiotics include a variety of strains with strain-specific functions, different strains may be the reason for the lack of caries prevention in some clinical trials. The potential probiotic strains with a strong colonization ability and caries prevention effect in the oral cavity are the research hotspots for caries prevention probiotics.
ABSTRACT
Objective@#To investigate the risk factors for caries in preschool children to provide a scientific basis for the prevention and treatment of caries in primary teeth.@*Method@#From July 2017 to September 2017, 183 children aged 3-6 who received treatment for caries in the Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, were randomly selected for recording of the caries status of deciduous teeth, and a questionnaire was collected from their guardians. Risk factors for caries in primary teeth were analyzed using SPSS 21.0 software．@*Results@#The mean dmft (decayed, missing and filled teeth) value of all samples was 9.91 ± 5.12. There was no significant difference in dmft between boys (10.38 ± 5.26) and girls (9.55 ± 5.01) (t = -1.088, P > 0. 05). There were 40 cases (21.86%) in the mild caries group (dmft = 3.13 ± 1.34) and 143 cases in the severe group (dmft = 11.80 ± 4.07). Oral hygiene before one year of age, duration of tooth brushing, number of oral hospital examinations and frequency of sugar intake were significantly associated with caries status (P < 0.05). Children who brushed their teeth for less than 2 minutes and consumed sugar frequently had high dmft values. Duration of tooth brushing and frequency of sugar intake were significantly associated with caries in the primary teeth (P < 0.05).@*Conclusion@#Insufficient tooth brushing time and frequent sugar intake are major risk factors for deciduous caries.