Cinnamon essential oil (CEO) has antibacterial properties, but its ability to suppress the formation of multi-species oral biofilms has not been fully elucidated. This study evaluated the antibacterial and antibiofilm activities of cinnamon essential oil nanoemulsion (CEON) against oral biofilms formed using a microcosm biofilm model. The biofilms were formed on bovine enamel specimens over a 7-day period, during which all specimens were treated with one of three solutions: 5% CEON (n = 35), 0.5% cocamidopropyl betaine (n = 35), or 0.12% chlorhexidine gluconate (CHX; n = 35). Antibacterial and antibiofilm activities were determined by the red/green ratios (R/G values) of 7-day-old mature biofilms photographed with quantitative light-induced fluorescence-digital, the number of aciduric bacterial colony-forming units (CFUs) within each biofilm, and the absorbance of bacterial suspensions. One-way and repeated-measures analysis of variance were performed to compare differences among the three solutions. R/G values were lowest in the 0.12% CHX group, but not significantly differ from the 5% CEON group. The number of CFUs and absorbance were lowest in the 5% CEON group. This study showed that nanoemulsified CEO inhibited the maturation of multi-species oral biofilms and the growth of oral microorganisms in biofilms, including aciduric bacteria that cause dental caries.

Most previous studies addressing dysphagia examined individuals who already had diseases causing dysphagia and did not pay much attention to oral health conditions as a risk factor. This pilot study investigated 62 healthy adults aged 65 years or older who were living independently in the community, performed basic activities of daily living independently, and had no history of a causative disease of dysphagia to identify the factors associated with dysphagia risk, especially oral health. The Dysphagia Risk Assessment Scale was used to screen the patients for dysphagia. Hyposalivation was diagnosed by evaluating the unstimulated salivary flow rate, and orofacial muscle strength (anterior tongue elevation, buccinator muscle, and lip strength) was quantitatively measured using the Iowa Oral Performance Instrument. To analyze the factors associated with dysphagia risk, the Mann–Whitney test, Kruskal–Wallis test, and multiple logistic regression analyses were conducted. In the final regression model adjusted for sociodemographic characteristics, the oral health-related factors independently associated with dysphagia risk were buccinator muscle strength, hyposalivation, and subjective masticatory discomfort (p < 0.05). Therefore, our findings suggest that weak buccinator muscle strength, hyposalivation, and subjective masticatory discomfort are valuable indicators for the early detection of dysphagia in older, healthy, independent, community-dwelling adults.

This study used data from the Korea National Health and Nutrition Examination Survey 2014–2015 database to analyze the association between periodontitis and handgrip strength, a representative measure of hand impairment and function, in adults aged ≥30 years. The data of 5926 adults (male: 2766, females: 3160) who underwent handgrip strength and periodontal tissue examination and had neither rheumatoid arthritis nor osteoarthritis were analyzed. Handgrip strength was assessed using a digital grip strength dynamometer. The average values of the right handgrip strength, calculated separately by sex and age group (five 10-year age groups), were used as the cut-off for reduced handgrip strength. Periodontal status was evaluated using the Community Periodontal Index, defining scores ≥ 3 as periodontitis. Chi-square test and multivariate logistic regression analyses were performed to compare the differences in the prevalence of periodontitis according to handgrip strength. In the final regression model adjusted for risk factors for periodontitis, the likelihood of periodontitis decreased as the level of handgrip strength increased (p < 0.05). Therefore, this study suggests that handgrip strength may be a valuable indicator of periodontal health.

There have been contradictory reports on the effects of vitamin D in the prevention of periodontitis. We analyzed the association between vitamin D status (levels of plasma 25(OH)D) and periodontitis using the Korea National Health and Nutrition Examination Survey (KNHANES) 2013–2014 database. Among the participants in the KNHANES (2013–2014), only those aged ≥60 years who completed a health interview survey, periodontal examination, and blood test were included in the study. Thus, data from 701 participants were used in the final analysis. Periodontal status was evaluated using the Community Periodontal Index (CPI), and periodontitis was defined as having a CPI score of 3 or 4. Plasma 25(OH)D levels were classified according to two criteria: 20 ng/mL and quartile value. The chi-square test and multivariate logistic regression analyses were performed to analyze the prevalence of periodontitis according to plasma 25(OH)D levels. Univariate analyses showed that periodontitis was not significantly associated with plasma 25(OH)D levels. In the multivariate logistic regression model adjusted for sociodemographic characteristics, the difference in the prevalence of periodontitis between those with a normal range of 25(OH)D and those with low plasma of 25(OH)D levels was not statistically significant. Vitamin D intake has been reported to have benefits in maintaining periodontal health; however, total plasma 25(OH)D levels showed no significant association with periodontitis based on CPI scores in this study. Additionally, these findings reaffirmed the importance of toothbrushing and smoking cessation to prevent periodontitis in people aged ≥60 years.