The association between periodontal disease and dementia/cognitive impairment continues to receive increasing attention. However, whether periodontal disease is a risk factor for dementia/cognitive impairment is still uncertain. This meta-analysis was conducted to comprehensively analyze the effect of periodontitis on dementia and cognitive impairment, and to assess the periodontal status of dementia patients at the same time. A literature search was undertaken on 19 October 2020 using PubMed, Web of Science, and Embase with different search terms. Two evaluators screened studies according to inclusion and exclusion criteria, and a third evaluator was involved if there were disagreements; this process was the same as that used for data extraction. Included studies were assessed with the Newcastle-Ottawa Scale (NOS), and results were analyzed using software Review Manager 5.2. Twenty observational studies were included. In the comparison between periodontitis and cognitive impairment, the odds ratio (OR) was 1.77 (95% confidence interval (CI), 1.31–2.38), which indicated that there was a strong relationship between periodontitis and cognitive impairment. There was no statistical significance in the effect of periodontitis on dementia (OR = 1.59; 95%CI, 0.92–2.76). The subgroup analysis revealed that moderate or severe periodontitis was significantly associated with dementia (OR = 2.13; 95%CI, 1.25–3.64). The mean difference (MD) of the community periodontal index (CPI) and clinical attachment level (CAL) was 0.25 (95%CI, 0.09–0.40) and 1.22 (95%CI, 0.61–1.83), respectively. In this meta-analysis, there was an association between periodontitis and cognitive impairment, and moderate or severe periodontitis was a risk factor for dementia. Additionally, the deterioration of periodontal status was observed among dementia patients.

Conventional treatments for chronic periodontitis are less effective in controlling inflammation and often relapse. Therefore, it is necessary to explore an immunomodulatory medication as an adjuvant. Ginsenoside Rb3 (Rb3), one of the most abundant active components of ginseng, has been found to possess anti-inflammatory and immunomodulatory properties. Here, we detected the anti-inflammatory effect of Rb3 on Porphyromonas gingivalis LPS-stimulated human periodontal ligament cells and experimental periodontitis rats for the first time. We found that the expression of pro-inflammatory mediators, including IL-1β, IL-6 and IL-8, upregulated by lipopolysaccharide (LPS) stimulation was remarkably downregulated by Rb3 treatment in a dose-dependent manner at both transcriptional and translational levels. Network pharmacological analysis of Rb3 showed that the mitogen-activated protein kinase (MAPK) signaling pathway had the highest richness and that p38, JNK, and ERK molecules were potential targets of Rb3 in humans. Western blot analysis revealed that Rb3 significantly suppressed the phosphorylation of p38 MAPK and p65 NF-κB, as well as decreased the expression of total AKT. In experimental periodontitis rat models, reductions in alveolar bone resorption and osteoclast generation were observed in the Rb3 treatment group. Thus, we can conclude that Rb3 ameliorated Porphyromonas gingivalis LPS-induced inflammation by inhibiting the MAPK/AKT/NF-κB signaling pathways and attenuated alveolar bone resorption in experimental periodontitis rats.

Aims The aim of this study was to identify new small molecules that can inhibit Streptococcus mutans biofilms by in vitro and in vivo model. Methods and Results We evaluated the effect of a small molecule 2‐amino‐imidazole/triazole conjugate (2‐AI/T) on the formation of Strep. mutans biofilms by culturing in 96‐well plates. Toxicity was assessed through cell culture and intragastrically administering to mice. The anti‐biofilm and anti‐caries effects were investigated in vivo. The inhibitive mechanism was detected by isobaric tag for relative and absolute quantification (itraq) and RT‐QPCR. In vitro and in vivo study revealed that 2‐AI/T significantly inhibited biofilm formation of Strep. mutans and is more so than inhibiting planktonic cells without toxicity. The ribosome and histidine metabolism pathways of Strep. mutans were significantly regulated by this compound. Conclusions These results suggest that the 2‐AI/T conjugate is a potent inhibitor that can be potentially developed into a new drug to treat and prevent dental caries. Significance and Impact of the Study This is the first study to use small molecule from marine natural products, to protect from dental caries in vivo. It has potential broad range application in clinical caries prevention, or as a bioactive ingredient for food applications.

Background: The sudden outbreak of coronavirus disease (COVID-19) epidemic influenced people’s daily life. During lockdown of Wuhan city, the oral health and its associated issues of preschool children were investigated and guidance for dental clinics when the epidemic were controlled in the future were also provided. Methods: A national online survey was conducted among preschool children and completed by their caregivers. The questionnaire related to children’s oral health status and care behaviour, caregivers' attitudes. The information was statistically analyzed between Wuhan residents and others residents. Results: 4495 valid questionnaires were collected. In oral health status, during Wuhan lockdown, 60.8%, 35.5% and 18.3% children had self-reported dental caries, toothache and halitosis respectively. In oral health attitudes, respondents who would increase attention to oral health was more than that would decrease. In oral hygiene behaviour, compared to non-Wuhan children, the children in Wuhan became more active in brushing their teeth. In utilization of dental services in the future, less Wuhan residents would choose to have dental visit directly, 28.5% Wuhan residents and 34.7% non-Wuhan residents agreed all of procedures could be done if proper protected. Conclusions: Oral health status and associated issues of preschool children in Wuhan were significantly different from that of others during lockdown of Wuhan city and in the future. Effective measures should be taken as early as possible to protect children's oral health.