The profile of cytokines against bacterial infection in dental pulp.

BACKGROUND: Dental pulp in a confined environment, with little connection to the outside and only a small distribution of immune cells, provides a good research model for investigating how cells respond to bacterial infections through cytokines. METHODS: The data of single-cell transcriptome sequencing of healthy and inflamed pulp tissue were downloaded from the GEO dataset. The expression character of 79 cytokines was analyzed based on the expression matrix. RESULTS: The cytokine secretion profiles of the two populations of pulp cells in healthy dental pulp were associated with vascularization and nervous system development, as well as immune cell regulation. For the three populations of pulp stem cells with stem cell activity in the dental pulp, the secretion of cytokines related to nervous system development, regulation of endothelial cell proliferation and migration, and regulation of immune cell function comprised the characteristics that we observed. The cytokines secreted by T cells and macrophages were more of an immune reserve against pathogenic microorganisms. In the inflammatory state, the spectrum of cytokines secreted by various types of cells in the dental pulp tended to be identical, such that it mainly resisted pathogenic microorganisms. CONCLUSIONS: The cytokine secretion profiles of various cell types in healthy and inflamed dental pulp at the single-cell level are summarized.

Study of mandibular buccal gingival mucosa pain sensitivity / 口腔疾病防治

Objective@# Through a pain study of buccal gingival mucosa sensitivity of the mandible, the corresponding sensitive area of pain was determined, which provided the basis for reducing the pain and discomfort of oral diagnosis and treatment.@*Methods@#400 patients with mandibular tooth extraction in the outpatient department of stomatology were selected. During tooth extraction, articaine epinephrine injection was used for infiltration anesthesia. The injection needle size was 0.3 mm × 21 mm, and the injection site was about 5 mm away from the buccal gingival margin. The pain degree of the patients was recorded. The data were statistically analyzed using the modified International pain classification method.@*Results @#Among the 400 patients who underwent mandible extraction, 75% (300 patients) graded their pain from painless to moderate, and 25% (100 patients) reported moderate to severe and severe pain. Of those in the moderate to severe and severe groups, 50% and 42% reported pain in the central and lateral incisors, respectively, and 38% were in the canine group. When comparing the moderate to severe and the severe groups, 16% and 10% were in the bicuspid group, 16% and 12% and 16% were in the molar group, respectively . There were significant differences in the pain sensitivity of different teeth positions (χ2=54.203, P < 0.001). The proportion of moderate to severe and severe pain in the anterior teeth group was higher than it was in the posterior teeth group (χ2=55.555, P < 0.001). There were significant differences in the pain sensitivity of different ages (χ2=96.501, P=0.000), and there was a positive correlation between pain and age (r=0.465, P < 0.001). The proportion of women with at least a moderate degree of pain was higher than that of men (χ2=12.298, P=0.031). @*Conclusion@# The sensitivity of the buccal gingival mucosa to pain is different in different positions of the mandible. The sensitivity of the anterior gingiva is higher than that of the posterior gingiva. Age is positively correlated with the degree of pain. Further, compared with men, women are more sensitive to pain.

BZW1, a novel proliferation regulator that promotes growth of salivary muocepodermoid carcinoma.

Mucoepidermoid carcinoma (MEC) is the most common primary malignancy in the salivary glands; however, its oncogenesis is poorly understood. Here, we show that the homo sapiens basic leucine zipper and W2 domains 1 (BZW1 or BZAP45) is a critical factor in the regulation of MEC growth. Firstly, BZW1 was highly expressed in MEC tissues and cells, determined by quantitative real time polymerase chain reaction. Higher levels of BZW1 proteins were detected in MEC tissues, particularly in high-grade MEC, by immunohistochemistry. Furthermore, down-regulation of BZW1 expression by infection with BZW1-specific RNAi-expressing lentivirus inhibited Mc3 cell proliferation and colony formation in vitro. In addition, down-regulation of BZW1 expression arrested Mc3 cell cycling at the G(0)/G(1) phase and mitigated Mc3 cell migration and invasiveness in vitro, determined by wound healing and transwell invasion assays. Importantly, down-regulation of BZW1 expression significantly reduced the tumorigenicity of Mc3 cells in vivo, evidenced by the slow progression of small tumors induced by BZW1-specific RNAi expressing Mc3 cells. Apparently, BZW1 is a novel factor, promoting the growth of MEC cells. Our findings may provide a base for design of new strategy for diagnosis and therapy for human MEC.

Three-dimensional finite element analysis of weakened roots restored with different cements in combination with titanium alloy posts.

BACKGROUND: It is very difficult and relatively unpredictable to preserve and restore severely weakened pulpless roots. To provide much needed benefit basis for clinical practice, this study was carried out to analyze the stress distribution in weakened roots restored with different cements in combination with titanium alloy posts. Finite element analysis (FEA) was employed in the study. METHODS: A pseudo three-dimensional model of a maxillary central incisor with flared root canal, theoretically restored with titanium alloy posts in combination with different cements, was established. The analysis was performed by use of ANSYS software. The tooth was assumed to be isotropic, homogenous and elastic. A load of 100 N at an angle of 45 degrees to the longitudinal axis was applied at the palatal surface of the crown. The distributions of stresses in weakened roots filled with cements of different elastic modulus were analyzed by the three-dimensional FEA model. RESULTS: Several stress trends were observed when the stress cloud atlas obtained in the study was analyzed. With the increase of the elastic modulus of cements from 1.8 GPa to 22.4 GPa, the stress values in dentin decreased from 39.58 MPa to 31.43 MPa and from 24.51 MPa to 20.76 MPa (respectively, for maximum principle stress values and Von Mises stress values). When Panavia F and zinc phosphate cement were used, the stress peak values in dentin were very small with no significant difference observed, and the Von Mises stress values were 20.87 MPa and 20.76 MPa respectively. On the other hand, maximum principle stress value and Von Mises stress value in cement layer increased with the increase of the elastic modulus of cements. CONCLUSIONS: The result of this study demonstrated that elastic modulus was indeed one of the important parameters to evaluate property of the cements. Our three-dimensional FEA model study also found that the cement with elastic modulus similar to that of dentin could reinforce weakened root and reduce the stress in dentin. Thus, it may be a better choice for the restoration of weakened roots in clinical practice.