Vitamin C is important for preventing and slowing the progression of many diseases. There is significant evidence linking periodontal disease and vitamin C. We aimed to systematically review the studies addressing the relationship between vitamin C and periodontal disease, and the preventive ability of vitamin C against periodontal disease. Electric searches were performed using PubMed, EMBASE, Cochrane Library, and Web of Science. Studies addressing the relationships between periodontal disease and vitamin C in adults aged over 18 years were included. Quality assessment was done using the Critical Appraisal Skills Program guideline and GRADE-CERQual. There were 716 articles that were retrieved and 14 articles (seven cross-sectional studies, two case-control studies, two cohort studies, and three randomized controlled trials (RCT)) were selected after reviewing all of the articles. The vitamin C intake and blood levels were negatively related to periodontal disease in all seven cross-sectional studies. The subjects who suffer from periodontitis presented a lower vitamin C intake and lower blood-vitamin C levels than the subjects without periodontal disease in the two case-control studies. The patients with a lower dietary intake or lower blood level of vitamin C showed a greater progression of periodontal disease than the controls. The intervention using vitamin C administration improved gingival bleeding in gingivitis, but not in periodontitis. Alveolar bone absorption was also not improved. The present systematic review suggested that vitamin C contributes to a reduced risk of periodontal disease.

Psychological stress in a chronic course is implicated in various diseases, such as coronary artery disease, diabetes, ulcerative colitis, and psychosomatic pain disorders. Commensal microbiota in the host tissues interact with each other and maintain overall health. Oral and gut microbiomes are considered as the most ecologically rich and taxonomically diverse microbiota communities in humans. The effects of psychological stress on the gut microbiome have been well documented, and the interaction is commonly referred as the microbiota-gut-brain axis. Like the gut microbiome, the oral microbiome contributes to maintaining both local and systemic health. Although the effects of psychological stress on the oral microbiome have been studied, comprehensive knowledge about the oral-brain axis is lacking. The oral cavity and gut can communicate with each other through the microbiota. Three-way interactions within the oral-gut-brain microbiota might exist in patients with psychological stress and disorders. The effect of psychological stress on the gut and oral microbiomes, and the potential interactions within the oral-gut-brain axis are discussed in this review.

The World Health Organization (WHO) states that examining medical financial systems is the most important process in evaluating universal health coverage (UHC). This study used the service coverage index (SCI) as a proxy of the progress toward UHC in eleven Asian countries. We employed a fixed-effects regression model to analyze panel data from 2015 to 2017, to explain the interrelationship between the SCI and major socioeconomic indicators. We also conducted a performance analysis (ratio of achieved SCI level to gross domestic product (GDP) or health expenditure displacement) to examine the balance between the degree of achievements related to UHC and a country’s economic level. The results showed that GDP and health expenditure were significantly positively correlated with the SCI (p < 0.01). The panel data analysis results showed that GDP per capita was a factor that greatly influenced the SCI as well as poverty (partial regression coefficient: 0.0017, 95% CI: 0.0013–0.0021). The results of the performance analysis showed that the Philippines had the highest scores (GDP: 1.84 SCI score/USD per capita, health expenditure: 1.04 SCI score/USD per capita) and South Korea the lowest. We conclude that socioeconomic factors, such as GDP, health expenditure, unemployment, poverty, and population influence the progress of UHC, regardless of system maturity or geographic characteristics.

Vitamin C is important in preventing and slowing the progression of many diseases. There is significant evidence linking periodontal disease and vitamin C. We aimed to systematically review studies addressing the relationship between vitamin C and periodontal disease and the preventive ability of vitamin C against periodontal disease. Electric searches were performed using PubMed, EMBASE, Cochrane Library, and Web of Science. Studies addressing the relationships between periodontal disease and vitamin C in adults aged over 18 years were included. Quality assessment was done using Critical Appraisal Skills Program guideline and GRADE-CERQual. Seventy hundred and sixteen articles were retrieved and fifteen articles (7 cross-sectional studies, 2 case-control studies, 2 cohort studies, and 4 randomized controlled trial [RCT]) were selected by reviewing all articles. Vitamin C intake and blood level were negatively related to periodontal disease in all 7 cross-sectional studies. Subjects who suffer from periodontitis presented lower vitamin C intake and lower blood vitamin C level than subjects without periodontal disease in the two case-control studies. Patients with lower dietary intake or lower blood level of vitamin C showed greater progression of periodontal disease than did the controls. Intervention using vitamin C administration improved gingival bleeding in gingivitis but not in periodontitis. Alveolar bone absorption was also not improved. The present systematic review suggested that vitamin C contributes to reduced risk of periodontal disease.

Periodontal disease is a common inflammatory disease. It affects about 20–50% of global population in both developed and developing countries. Early detection of slight changes of periodontal tissue plays an important role in prevention of onset and progression of periodontal disease. Hence, there is a need of a screening test to assess periodontal tissue for health check-ups. Salivary levels hemoglobin (Hb) has been proposed to assess the conditions of the inflammation of gingiva. The aim of this systematic review was to evaluate and summarize critically the current evidences for Hb as periodontal screening test. We performed a literature search of report published using PubMed databases. A total of 55 articles were retrieved and 16 were selected. Our review focuses on corelation coefficient with periodontal clinical parameters or sensitivity and specificity. As a result, fourteen studies calculated sensitivity and specificity of Hb. Six studies measured salivary levels hemoglobin at laboratory: three studies used polyclonal antibody reactions and other studies used colorimetric tests. Eight studies used paper strip method: 4 studies used monoclonal antibody reaction and 4 studies used colorimetric tests. Youden’s indexes by antibody reaction were better than those of colorimetric methods. Evidences are described above and further studies are necessary to set the cut off values stratified by gender, age and number of remaining teeth.

The aim of this study was to define the profile of unemployed dental hygienists who could be enticed to re-enter the workforce and the factors that could facilitate their re-entry into the dental field in Japan. The questionnaire was mailed with a postage-paid return envelope to a sample of 3095 licensed dental hygienists. A 50.4% response rate (S = 1477) was observed. The rate of working dental hygienists was 60.3% (n = 891), and of unemployed dental hygienists was 39.7% (n = 586). Of the latter, 31.9% (n = 187) stated intentions of returning to the workplace. The unemployed dental hygienists seeking employment were more often married and had more children, compared with working dental hygienists currently. This group also had significantly fewer total service years. Moreover, only 11.96% of them belonged to the Japan Dental Hygienists' Association, and 41.3% of those attended training workshops. According to their response, they perceived their top three major barriers to re-entry as 'lack sufficient dental hygiene skill', 'child rearing' and 'poor working atmosphere'. 'Flexibility in the work schedule' and 'location' were the most important factors for re-entry from their perspective. There were not many dental hygienists hoping to return to the dental field. The findings suggested that strategies to encourage non-practicing dental hygienists to re-entry should be emphasized in the areas of a flexible working atmosphere, easy access to information on how to return to practice and guidance on how to maintain professionalism during inactivity.