PURPOSE: Several studies have shown that the oral cavity is a secondary location for Helicobacter pylori colonization and that H. pylori is associated with the severity of periodontitis. This study investigated whether H. pylori had an effect on the periodontium. We established an invasion model of a standard strain of H. pylori in human periodontal ligament fibroblasts (hPDLFs), and evaluated the effects of H. pylori on cell proliferation and cell cycle progression. METHODS: Different concentrations of H. pylori were used to infect hPDLFs, with 6 hours of co-culture. The multiplicity of infection in the low- and high-concentration groups was 10:1 and 100:1, respectively. The Cell Counting Kit-8 method and Ki-67 immunofluorescence were used to detect cell proliferation. Flow cytometry, quantitative real-time polymerase chain reaction, and western blots were used to detect cell cycle progression. In the high-concentration group, the invasion of H. pylori was observed by transmission electron microscopy. RESULTS: It was found that H. pylori invaded the fibroblasts, with cytoplasmic localization. Analyses of cell proliferation and flow cytometry showed that H. pylori inhibited the proliferation of periodontal fibroblasts by causing G2 phase arrest. The inhibition of proliferation and G2 phase arrest were more obvious in the high-concentration group. In the low-concentration group, the G2 phase regulatory factors cyclin dependent kinase 1 (CDK1) and cell division cycle 25C (Cdc25C) were upregulated, while cyclin B1 was inhibited. However, in the high-concentration group, cyclin B1 was upregulated and CDK1 was inhibited. Furthermore, the deactivated states of tyrosine phosphorylation of CDK1 (CDK1-Y15) and serine phosphorylation of Cdc25C (Cdc25C-S216) were upregulated after H. pylori infection. CONCLUSIONS: In our model, H. pylori inhibited the proliferation of hPDLFs and exerted an invasive effect, causing G2 phase arrest via the Cdc25C/CDK1/cyclin B1 signaling cascade. Its inhibitory effect on proliferation was stronger in the high-concentration group.
Blotting, Western ; CDC2 Protein Kinase ; Cell Count ; Cell Cycle ; Cell Proliferation ; Coculture Techniques ; Colon ; Cyclin B1 ; Cytoplasm ; Fibroblasts ; Flow Cytometry ; Fluorescent Antibody Technique ; G2 Phase ; Helicobacter pylori ; Helicobacter ; Humans ; Methods ; Microscopy, Electron, Transmission ; Mouth ; Periodontal Ligament ; Periodontitis ; Periodontium ; Phosphorylation ; Real-Time Polymerase Chain Reaction ; Serine ; Tyrosine

Dental caries are the most common and widespread biofilm-dependent oral disease. Nanotechnology promises to be a useful strategy for dental caries management by combating caries-related bacteria, decreasing biofilm accumulation, inhibiting demineralization and enhancing remineralization. Many potential applications of nanotechnology in the development of anticaries materials have recently been reported, especially for anticaries adhesive nanomaterials and anticaries nanofilled composite resins. This review summarizes the current progress in the application of functional nanoparticles in the following products: antibacterial nanomaterials, remineralizing nanomaterials and nanodrug delivery systems.

Regenerative endodontic procedures, based on dental pulp biology, use the basic principles of tissue engineering to promote the functional regeneration of dental pulp-dentin complexes. Good results have been achieved in the treatment of young permanent teeth with pulp necrosis or apical periodontitis. There have also been preliminary clinical explorations of the treatment of mature permanent teeth in recent years. The key to successful treatment is controlling infection as well as promoting tissue repair and regeneration. Moderate root canal mechanical preparation is allowed in the therapy of mature permanent teeth, while it is not recommended in the treatment of young permanent teeth. The choice of root canal irrigation and intracanal antisepsis requires a comprehensive consideration of the antibacterial effects, biological safety, and possible complications, such as crown discoloration and root canal calcification. The development of bioceramic materials provides more options for crown sealing materials, but further clinical evaluation is needed. In addition to traditional blood clot scaffolds, new types of tissue scaffolds represented by platelet-rich plasma, platelet-rich fibrin, concentrated growth factors and other platelet concentrates have been developed. Long-term and large-scale studies are needed to evaluate the actual clinical efficacy of these new scaffolds and the efficacy of their combined application with blood clots.

OBJECTIVE: To construct antimicrobial peptides with potent antimicrobial activity, low cytotoxicity and efficient killing rate of for prevention and treatment of dental caries. METHODS: We exploited the existing design strategies to modify reutericin 6 or gassericin A produced by species in the oral cavity based on their cationicity, amphipathicity and -helical structure. We examined their antimicrobial activities using bacterial susceptibility assay, their cytotoxicity through cytotoxicity assay and their killing rate of with time-kill assay. We further evaluated the candidate derivatives for their killing rate against , their antimicrobial activity against different oral pathogens and the development of drug resistance. RESULTS: We constructed 6 AT-1 derivatives, among which AT-7 showed an MIC of 3.3 μmol/L against , and with a killing rate of 88.7% against within 5 min. We did not obtain strains of resistant to AT- 7 after induction for 10 passages. CONCLUSIONS Hydrophobicity and imperfect amphipathic structure are two key parameters that define the antimicrobial potency of the antimicrobial peptides. The imperfectly amphipathic peptide AT-7 shows the potential for clinical application in dental caries treatment.
Anti-Infective Agents ; Dental Caries ; Humans ; Microbial Sensitivity Tests ; Peptides ; Streptococcus mutans