Knowledge of dental academics about the COVID-19 pandemic: a multi-country online survey.

BACKGROUND: COVID-19 is a global pandemic affecting all aspects of life in all countries. We assessed COVID-19 knowledge and associated factors among dental academics in 26 countries. METHODS: We invited dental academics to participate in a cross-sectional, multi-country, online survey from March to April 2020. The survey collected data on knowledge of COVID-19 regarding the mode of transmission, symptoms, diagnosis, treatment, protection, and dental treatment precautions as well as participants' background variables. Multilevel linear models were used to assess the association between dental academics' knowledge of COVID-19 and individual level (personal and professional) and country-level (number of COVID-19 cases/ million population) factors accounting for random variation among countries. RESULTS: Two thousand forty-five academics participated in the survey (response rate 14.3%, with 54.7% female and 67% younger than 46 years of age). The mean (SD) knowledge percent score was 73.2 (11.2) %, and the score of knowledge of symptoms was significantly lower than the score of knowledge of diagnostic methods (53.1 and 85.4%, P <  0.0001). Knowledge score was significantly higher among those living with a partner/spouse than among those living alone (regression coefficient (B) = 0.48); higher among those with PhD degrees than among those with Bachelor of Dental Science degrees (B = 0.48); higher among those seeing 21 to 30 patients daily than among those seeing no patients (B = 0.65); and higher among those from countries with a higher number of COVID-19 cases/million population (B = 0.0007). CONCLUSIONS: Dental academics had poorer knowledge of COVID-19 symptoms than of COVID-19 diagnostic methods. Living arrangements, academic degrees, patient load, and magnitude of the epidemic in the country were associated with COVD-19 knowledge among dental academics. Training of dental academics on COVID-19 can be designed using these findings to recruit those with the greatest need.

Impacts of undernutrition and maternal oral health status on dental caries in Korean children aged 3-5 years.

INTRODUCTION: The association between nutrition and oral health has been studied in the elderly. This study aimed to examine the impacts of undernutrition and the mothers' socioeconomic and oral health statuses on the incidence of dental caries in Korean preschool children. METHODS: Data of 610 children aged 3-5 years and their mothers who underwent oral examinations and responded to the questionnaires in the 6th KNAHNES were used. Caries prevalence was measured by dft and dt among the primary teeth in children and DMFT among mothers. Dietary reference intake values were used to evaluate nutritional status, a nutritional quality index and the mean nutrient adequacy ratio. Complex sample correlation analysis was performed by using children's dft and dt statuses as dependent variables. Multilevel linear regression was applied to investigate the impacts of undernutrition and mothers' socioeconomic and oral health status on children's dft and dt statuses. Statistical significance was set as P < .05. RESULTS: Factors significantly related to dft in children were age and food. Food insecurity was the only factor significantly associated with dt in children. Children's sex and mother's DMFT were likely to be relevant to dft in children. Children's age and a nutritional quality index value less than 1 were also likely to be relevant to the dt of children. CONCLUSIONS: Children with an undernourished status had a higher caries experience. A comprehensive community dental health promotion programme should be developed to prevent the incidence of dental caries in vulnerable undernourished children.

Association of stress, depression, and suicidal ideation with subjective oral health status and oral functions in Korean adults aged 35 years or more.

BACKGROUND: Oral health greatly affects well-being throughout the different stages of life from childhood to late adulthood. Loss of teeth due to poor oral health hinders mastication, leading to poor nutrition absorption, and affects pronunciation and aesthetics, leading to interpersonal difficulties. As social activities become limited, a sense of isolation and loneliness, stress, and depression grows while happiness decreases. This study aimed to examine the association of stress, depression, and suicidal ideation with oral health status and oral functions in a large nationwide sample of Korean adults aged 35 years or more. METHODS: The sample comprised 15,716 adults, selected using a rolling survey sampling method and data were extracted from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES) (2010-2012). Participants were interviewed about their self-evaluation of health including oral health status and mental health, such as stress, depression, and suicidal ideation. Data from 11,347 adults were finally selected after excluding participants with missing answers. The dependent variables were stress, depression, and suicidal ideation. The independent variables were gender, age, household income, education, smoking, drinking, oral health perception, chewing, and speaking. Complex samples logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Participants met the criteria for stress (25.4%), depression (13.0%), and suicidal ideation (13.9%). Subjective oral health status was not significantly associated with stress, depression, and suicidal ideation. However, the presence of very uncomfortable chewing problems was significantly associated with stress (OR = 2.294, 95% CI = 1.41, 3.72), depression (OR = 3.232, 95% CI = 1.97, 5.31), and suicidal ideation (OR = 2.727, 95% CI = 1.58, 4.72). The presence of very uncomfortable speaking problems was significantly associated with stress (OR = 1.592, 95% CI = 1.13, 2.24) but not significantly associated with depression and suicidal ideation. CONCLUSIONS: Oral functional problems including chewing and speaking difficulties can be associated with mental health. It is necessary to develop oral health promotion programs for adults and help them maintain a good quality of life and mental health.

The decline in dental caries among Korean children aged 8 and 12 years from 2000 to 2012 focusing SiC Index and DMFT.

BACKGROUND: The aim of this study was to analyse the prevalence and severity of dental caries among Korean children aged 8 and 12 years over a period of 12 years by determining the number of decayed, missing, and filled teeth (DMFT) and the Significant Caries index (SiC index). METHODS: Stratified cluster-sampled data from the National Oral Health Survey conducted from 2000 to 2012 were analysed. In 2000, 2006, and 2012, a total of 2397, 2650, and 9601 children aged 8 and 12 years were examined, respectively. The children's oral health status, including the number of DMFT and fissures sealed teeth, was examined and recorded. The SiC index was calculated according to the child's residential district. RESULTS: Over the 12-year period, the percentages of caries-free children aged 8 and 12 years increased from 26.0 to 42.7 % and from 53.4 to 69.6 %, respectively. The percentages of children aged 8 and 12 years with sealed teeth in 2012 were 62.1 and 62.5 %, respectively, more than triple the rates in 2000. The mean DMFT values of children aged 8 and 12 years decreased from1.04 to 0.67 and from 2.86 to 1.84, respectively. The SiC index of children aged 8 and 12 years also decreased from 2.73 to 1.97 and from 6.13 to 4.51, respectively. The rate of reduction in DMFT among 8- and 12-year-old children in the second 6 years of the observation period was lower than that in the first 6 years. CONCLUSIONS: A remarkable decline in dental caries of 8- and 12-year-old Korean children was observed over the 12-year study period. The mean DMFT values and SiC index of children aged 8 and 12 years decreased. The reduction rate between 2000 and 2006 was higher than that between 2006 and 2012.

Association between estimated fluoride intake and dental caries prevalence among 5-year-old children in Korea.

BACKGROUND: The purposes of this study were to estimate the fluoride intake from food and drink in 5-year-old Korean children, and to measure the association between estimated fluoride intake and dental caries prevalence. METHODS: The study involved a secondary analysis of raw data from the 4(th) Korea National Health and Nutrition Examination Survey (KNHANES; 2007-2009). The study subjects were 167 boys and 147 girls aged 5 years who had undergone both physical and nutritional examination as part of the survey. The KNHANES comprised a health questionnaire, a physical examination, and a nutritional examination. The nutritional examination of KNHANES consisted of 3 parts: a dietary life survey, a food-frequency questionnaire, and a food intake investigation. The food intake investigation used the 24-h recall method, with information being provided by the children's parents. On the basis of this information, we evaluated the fluoride content in a total of 310 food items using the hexamethyldisiloxane (HMDS)-facilitated diffusion method, modified using Taves' microdiffusion method. As part of the KNHANES survey, oral examinations were conducted at a mobile examination centre by trained dentists using dental mirrors under a fluorescent light. These examinations were performed using methods proposed by the World Health Organization. RESULTS: The dietary fluoride intake of 5-year-old Korean children was estimated to be 0.35 mg/day, or 0.016 mg/kg/day. The "decayed or filled surfaces" (dfs) indices of primary teeth were higher in children who had a lower dietary intake of fluoride. There was a significant inverse association between dietary fluoride intake and the prevalence of dental caries. CONCLUSION: The inverse association between dietary fluoride intake levels and prevalence of dental caries implies that the introduction of community caries prevention programmes may be beneficial. Such programmes would include water fluoridation and a fluoride supplementation programme.

Association between viral hepatitis B infection and halitosis.

OBJECTIVE: Oral malodor can be increased in breath of liver patients. However, no study has been performed for the association between volatile sulfur compounds (VSCs) and viral hepatitis. The aim of the present study was to determine the relationship between viral hepatitis and VSCs. METHODS: This study analyzed 182 subjects and measured hydrogen sulfide (H2S), methyl mercaptan (CH3SH) and dimethyl sulfide [(CH3)2S] using the OralChroma(®). Hepatitis type B was evaluated. Periodontal health was assessed using the Community Periodontal Index (CPI) and bleeding on probing (BOP). Tongue coating score (TCS) was evaluated. Multiple logistic regression analyses were conducted to evaluate the relationship. RESULTS: Viral hepatitis had an elevated odds of dimethyl sulfide defined halitosis (OR = 9.22, 95% CI = 2.08-40.95) after controlling for age, gender, alcohol consumption, current smoking, periodontitis, BOP, TCS and tongue brushing habit. The magnitude of the association between viral hepatitis and VSCs defined halitosis attenuated with adjustment of mediators (alcohol consumption, periodontitis, BOP, TCS and tongue brushing habit for hydrogen sulfide defined halitosis; periodontitis, TCS and tongue brushing habit for methyl mercaptan defined halitosis; tongue brushing habit for dimethyl sulfide defined halitosis). CONCLUSIONS: Findings of this study suggest that viral hepatitis may be associated with methyl mercaptan defined halitosis.

Nitric oxide modulates levels of salivary Lactobacilli.

OBJECTIVE: Nitric Oxide (NO) is one of the most powerful antibacterial compounds. The aim of this study was to determine the association between salivary NO, dental caries and cariogenic bacteria. MATERIALS AND METHODS: The salivary NO concentration of 257 Korean children was analyzed by the Griess colorimetric reaction method. Salivary mutans streptococci (MS) and Lactobacilli (LB) were counted using the Dentocult MS and Dentocult LB kit, respectively. Dental caries status was examined using the WHO criteria. Confounders were age, gender, salivary flow rate and salivary buffer capacity. Analysis of covariance (ANCOVA) was used to evaluate the association among NO, salivary MS level, salivary LB level and dental caries status after adjusting for the effects of confounders. RESULTS: A significant decrease was found in salivary NO levels as the salivary LB count increased after controlling for confounders (p = 0.049). However, the MS level, caries experience and active caries status showed no significant association. CONCLUSION: This result indicates that NO production might be a host defense mechanism against the growth of cariogenic bacteria.

Salivary bisphenol-A levels due to dental sealant/resin: a case-control study in Korean children.

Dental sealants and composite filling materials containing bisphenol-A (BPA) derivatives are increasingly used in children. The aim of this study was to evaluate the association between salivary BPA and the number of tooth surfaces filled with dental sealant, and to determine a cutoff BPA level. Salivary BPA concentration and the number of tooth surfaces filled with dental sealant/resin were determined in 124 age and gender matched children: 62 controls had no dental sealant/resin on their tooth surfaces and 62 cases had more than 4 tooth surfaces with dental sealant/resin. Analysis of covariance (ANCOVA) and conditional logistic regression were performed after controlling for age, gender, salivary flow rate, salivary buffer capacity, frequency of snacking, and frequency of tooth brushing. Salivary BPA levels were 0.002 to 8.305 µg/L. The BPA level of control (0.40 µg/L) was significantly lower than that of case (0.92 µg/L) after controlling for confounders (P = 0.026). Although the 90th BPA percentile had an adjusted OR of 4.58 (95% CI 1.04-20.26, P = 0.045), the significance disappeared in the conditional logistic model. There may be a relationship between salivary BPA level and dental sealant/resin.

Global self-rating of oral health, concerns about oral health, and history of jaw injury related to temporomandibular joint symptoms in Korean adults.

AIMS: To examine the association between temporomandibular joint (TMJ) symptoms and the global self-rating of oral health, concerns about oral health, and a history of jaw injury or third molar extraction in a representative Korean population. METHODS: From the Korean National Oral Health Survey 2006, 4,546 adults aged 18 years and older were included in the analysis. The dependent variable was TMJ symptoms. The independent variables were the global self-rating of oral health, concerns about oral health, and a history of jaw injury or third molar extraction. The demographic information (age and gender), socioeconomic status (education level, monthly household income, vocation, and residence), and behavioral factors (recent dental visit and smoking) were evaluated as confounders. Multivariate linear and logistic regression analyses were applied. RESULTS: The overall prevalence of TMJ symptoms in Koreans was 15.3%. The younger, more educated, middle class, those employed in office and sales, and those who resided in city areas had more TMJ symptoms. The TMJ symptoms were significantly associated with the global self-rating of oral health, concerns about oral health, and history of jaw injury. No significant association was found between the TMJ symptoms and a history of a third molar extraction. The global self-rating of oral health, concerns about oral health, and history of jaw injury had a dose-effect relationship with the severity of TMJ symptoms. Age and gender modified the effect of the global self-rating of oral health, concerns about oral health, and the history of jaw injury on TMJ symptoms. CONCLUSION: The global self-rating of oral health, concerns about oral health, and a history of jaw injury might be associated with TMJ symptoms.

Relationships Between Oral-Mucosal Pressure Ulcers, Mechanical Conditions, and Individual Susceptibility in Intubated Patients Under Intensive Care: A PCR-Based Observational Study.

PURPOSE: This study was performed to determine the relationship between oral-mucosal pressure ulcer (PU) stage and mechanical conditions and individual susceptibility in intubated patients. METHODS: We collected 80 patient-days data from an intensive care unit of a 700-bed hospital in Korea. We analyzed oral-mucosal PUs, medical records, amount of saliva, and oral mucosal swabs. Bacterial abundance was enumerated by real-time polymerase chain reaction. The χ2 or Fisher's exact test, t-test or Mann-Whitney U test, and Spearman's rho correlation analysis were performed. RESULTS: The incidence of overall oral-mucosal PUs was 31.3%, and in the maxillary and mandibular sites were 16.3% and 26.3%, respectively. There were significant correlations between the maxillary site PU stage and restraint use (r = .43, p < .001), albumin level (r = -.22, p = .046), and relative abundance of P. aeruginosa (r = .45, p < .001) and S. aureus (r = -.24, p = .033). In the mandibular sites, there were significant correlations between PU stage and restraint use (r = .30, p = .008), level of consciousness (r = .31, p = .005), and relative abundance of P. aeruginosa (r = .25, p = .028) and S. pneumoniae (r = .22, p = .046). CONCLUSIONS: Frequent monitoring and repositioning the mechanical pressure on the oral-mucosa could be an effective preventive strategy against the development and advancement of oral-mucosal PUs. Additionally, monitoring the oral microorganisms can prevent advanced stage oral-mucosal PUs in intubated patients.

Perceived Preparedness of Dental Academic Institutions to Cope with the COVID-19 Pandemic: A Multi-Country Survey.

Dental academic institutions are affected by COVID-19. We assessed the perceived COVID-19 preparedness of these institutions and the characteristics of institutions with greater perceived preparedness. An international cross-sectional survey of dental academics was conducted from March to August 2020 to assess academics' and institutional attributes, perceived preparedness, and availability of infection prevention and control (IPC) equipment. Principal component analysis (PCA) identified perceived preparedness components. Multilevel linear regression analysis assessed the association between perceived preparedness and fixed effect factors (academics' and institutions' attributes) with countries as random effect variable. Of the 1820 dental academics from 28 countries, 78.4% worked in public institutions and 75.2% reported temporary closure. PCA showed five components: clinic apparel, measures before and after patient care, institutional policies, and availability of IPC equipment. Significantly less perceived preparedness was reported in lower-middle income (LMICs) (B = -1.31, p = 0.006) and upper-middle income (UMICs) (B = -0.98, p = 0.02) countries than in high-income countries (HICs), in teaching only (B = -0.55, p < 0.0001) and in research only (B = -1.22, p = 0.003) than teaching and research institutions and in institutions receiving ≤100 patients daily than those receiving >100 patients (B = -0.38, p < 0.0001). More perceived preparedness was reported by academics with administrative roles (B = 0.59, p < 0.0001). Academics from low-income countries (LICs) and LMICs reported less availability of clinic apparel, IPC equipment, measures before patient care, and institutional policies but more measures during patient care. There was greater perceived preparedness in HICs and institutions with greater involvement in teaching, research, and patient care.

The decline in dental caries among children of different ages in Korea, 2000-2006.

AIM: To determine the prevalence of dental caries in Korean children with time after the introduction of the nationwide public oral health programme. DESIGN: Cross sectional oral health surveys of children aged from 6-16 years carried out in 2000 and 2006. PARTICIPANTS: After stratified cluster sampling, 11,947 (2000) and 9,740 (2006) children aged 6-16 years of age were examined at school. METHODS: DMFT and fissure sealants were recorded according to the WHO criteria. The significant Caries Index (SiC index) was calculated. MAIN OUTCOME MEASURES: DMFT, SiC index, and the prevalence of fissure sealants. RESULTS: The mean DMFT scores for the 12-year-old Koreans decreased from 2.86 in 2000 to 2.16 in 2006. The prevalence of caries free permanent dentition also increased in the same period. The average SiC index from 6-16 years also decreased. There was a 20% prevalence of subjects with fissure sealants in 9-11-year-old children in 2000. The corresponding figures increased to 40% in 2006. CONCLUSIONS: The oral health of Korean children improved considerably between 2000 and 2006 through improvement in lifestyle and the strong public oral health programme, which should be continued in order to improve oral health in Korea

Factors Related to Oral Healthcare Service Utilization among Korean Adults Aged 25-79 Years.

The factors related to oral healthcare service utilization (OHSU) among Korean adults aged 25-79 years were assessed using the Andersen model with the sixth Korean National Health and Nutrition Examination Survey data. The study included 12,937 participants aged 25-79 years who answered questions on the predisposing, enabling, and need factors related to OHSU at dental clinics within the past 1 year. Age, sex, and education level were selected as predisposing factors; household income, residence region, and national and private health insurance status as enabling factors; and self-perceived oral health, dental pain, chewing status, and discomfort while speaking as need factors. These factors were assessed using multivariable complex logistic regression models. OHSU at dental clinics within the past 1 year was lower among less-educated participants, those with low, middle-low, and middle-high household income levels, rural participants, those benefiting from the Medicaid system, and non-insured participants. OHSU was higher among older participants, those who rated their self-perceived oral health status as bad, those with experience of dental pain, and those who experienced discomfort while chewing and speaking. The need factors were the most influential. Thus, interventions to reduce inequalities in OHSU are required to promote oral health for all.

Injury Prevention, Safety Education and Violence in Relation to the Risk of Tooth Fracture among Korean Adolescents.

This study aimed to determine the injury prevention-, safety education-, and violence-related factors pertaining to tooth fracture experience (TFE) in Korean adolescents. We used data from the 14th Korea Youth Risk Behavior Survey (KYRBS) in 2018. The 60,040 participants were selected using a complex sampling design from middle and high schools. The participants completed a self-administered questionnaire. The explanatory variables, including school safety education and violence, were assessed in relation to prevention of traumatic injuries. Complex-samples multivariable logistic regression models were applied to explain the factors related to TFE over the past 12 months. The overall prevalence of TFE was 11.4%. Risk factors related to tooth fractures were not wearing a seatbelt on an express bus, not wearing helmets while riding motorcycles and bicycles, clinical treatment due to injuries at school, injuries associated with earphone/smartphones use, and lack of school safety education such as danger evacuation training. The top risk factor was injuries associated with earphone/smartphone usage, followed by lack of familiarity with school safety education. Thus, to prevent tooth fractures among adolescents, schools should strengthen their safety education, including education regarding mobile device usage, and wearing a seatbelt and wearing a helmet. Care should be taken to manage facilities around the school and to prevent injury related to tooth fracture. Further studies on various risk factors related to tooth fractures are warranted.

Health-Risk Behavior-, Mental Health-, and Physical Exercise-Related Risk Factors for Tooth Fractures in Korean Adolescents.

We aimed to determine factors related to tooth fracture experience in Korean adolescents. This study used data from the 14th Korea Youth Risk Behavior Survey in 2018, a cross-sectional web-based survey of health-risk behaviors among a representative sample of Korean middle- and high-school students aged 12-17 years. A total of 60,040 participants were selected using a complex sampling design of the survey from 400 middle schools and 400 high schools. They answered a self-administered questionnaire survey in classrooms. Explanatory variables included those pertaining to health-risk behaviors, mental health, and physical exercise. Complex-sample multivariable logistic regression models were applied to identify factors related to tooth fracture experience in the past 12 months. The overall prevalence of dental fracture experience was 11.4%. Risk factors related to tooth fractures in Korean adolescents were unhealthy behaviors such as alcohol and tobacco consumption; mental health problems including stress, depression, and suicidal ideation; and intensive physical exercise. The major risk factor related to tooth fractures was depression. To prevent tooth fractures among adolescents, schools should strengthen mental health education, encourage mouthguard use during intensive physical exercise, and develop school environments to prevent orofacial injuries. Further studies on various risk factors related to tooth fractures are warranted.

Association of Periodontitis with Atherosclerotic Cardiovascular Diseases: A Nationwide Population-based Retrospective Matched Cohort Study.

We investigated the association between periodontitis and atherosclerotic cardiovascular disease (ACVD) development using the National Health Insurance Service-National Sample Cohort 2.0 (NHIS-NSC2) database, which contains data for approximately 1 million nationally representative random participants. We selected 52,425 participants aged 20+ years and diagnosed with periodontitis from January to December 2003 and used propensity score matching to select an equivalent number of participants who were never diagnosed with periodontitis in the period covered by the NHIS-NSC2 database (2002-2015). The propensity scores were based on sex, age group, type of national health insurance, household income, diabetes status, and hypertension status and were used for 1:1 matching of individuals with similar propensities. A total of 104,850 participants were selected for the study. A multivariable Cox proportional hazard regression model was used to investigate the risk of ACVD development due to periodontitis from 2003 to 2015 after adjusting for sex, age, type of national health insurance, household income, hypertension status, and diabetes status. Participants with periodontitis had a higher risk of ACVD (adjusted hazard ratio: 1.09, 95% confidence interval: 1.05-1.13) than those without periodontitis. Thus, periodontitis can increase the risk of ACVD, and prevention of periodontitis may help reduce the risk of cardiovascular disease.

Association of Insufficient or Excess Sleep with Type 2 Diabetes Mellitus in the Presence of Periodontitis.

We aimed to investigate the effects of sleep duration on impaired fasting glucose and diabetes in Korean adults with periodontal disease. This cross-sectional study was performed using data for 10,465 subjects aged >19 years who completed the periodontal examination and questionnaires in the Sixth Korea National Health and Nutrition Examination Survey (2013-2015). The effect of sleep was confirmed by a complex-sample multinomial logistic regression analysis. Confounding variables were age, sex, household income, education level, smoking status, and sleep duration. Of all participants, 25.7% had periodontitis, of which 28.6% had fasting serum glucose disorder and 14.2% had diabetes. Among participants with periodontitis, the prevalence of diabetes was 1.49 times higher in participants with an average sleep duration of ≥8 h than those with an average sleep duration of 6-7 h. The prevalence of diabetes among participants without periodontitis was 1.49 times and 1.57 times higher in participants with an average sleep duration of ≤5 and ≥8 h, respectively, than those with an average sleep duration of 6-7 h. We found that altered sleep duration may be a risk factor for diabetes and that proper sleep duration is important to control diabetes incidence.

Behavior change due to COVID-19 among dental academics-The theory of planned behavior: Stresses, worries, training, and pandemic severity.

OBJECTIVE: COVID-19 pandemic led to major life changes. We assessed the psychological impact of COVID-19 on dental academics globally and on changes in their behaviors. METHODS: We invited dental academics to complete a cross-sectional, online survey from March to May 2020. The survey was based on the Theory of Planned Behavior (TPB). The survey collected data on participants' stress levels (using the Impact of Event Scale), attitude (fears, and worries because of COVID-19 extracted by Principal Component Analysis (PCA), perceived control (resulting from training on public health emergencies), norms (country-level COVID-19 fatality rate), and personal and professional backgrounds. We used multilevel regression models to assess the association between the study outcome variables (frequent handwashing and avoidance of crowded places) and explanatory variables (stress, attitude, perceived control and norms). RESULTS: 1862 academics from 28 countries participated in the survey (response rate = 11.3%). Of those, 53.4% were female, 32.9% were <46 years old and 9.9% had severe stress. PCA extracted three main factors: fear of infection, worries because of professional responsibilities, and worries because of restricted mobility. These factors had significant dose-dependent association with stress and were significantly associated with more frequent handwashing by dental academics (B = 0.56, 0.33, and 0.34) and avoiding crowded places (B = 0.55, 0.30, and 0.28). Low country fatality rates were significantly associated with more handwashing (B = -2.82) and avoiding crowded places (B = -6.61). Training on public health emergencies was not significantly associated with behavior change (B = -0.01 and -0.11). CONCLUSIONS: COVID-19 had a considerable psychological impact on dental academics. There was a direct, dose-dependent association between change in behaviors and worries but no association between these changes and training on public health emergencies. More change in behaviors was associated with lower country COVID-19 fatality rates. Fears and stresses were associated with greater adoption of preventive measures against the pandemic.

Reduction of Dental Caries Among Children and Adolescents From a 15-Year Community Water Fluoridation Program in a Township Area, Korea.

Since 2000, a community water fluoridation program (CWFP) has been implemented in Hapcheon for over 15 years. We aimed to evaluate the caries-reducing effect on permanent teeth after this implementation. In 2015, evaluation surveys were conducted by our study group, 498 subjects aged 8, 10, 12, and 15 years. As the control, 952 similarly aged subjects were selected from the Sixth Korean National Health and Nutrition Examination Survey (2013-2015 KNHANES). Data of a prospective cohort of 671 8-,10- and 12-year-olds, collected when CWFP started, were used for the evaluation. Caries-reducing effects were estimated by decayed, missing and filled teeth (DMFT) scores between CWFP and control groups, pre- and post-program. Confounders including the mean number of sealant teeth and gender were adjusted for. The mean adjusted DMFT scores of 10-, 12- and 15-year-olds in Hapcheon were significantly lower compared to KNHANES DMFT scores; in addition, those of 8-, 10- and 12-year-olds after the 15-year CWFP were significantly lower than in 2000. The caries-reducing effect among 12-year-olds was 37.6% compared to those recorded in KNHANES, and 67.4% compared to those in 2000. In conclusion, the caries-reducing effect was so high that health policy makers should consider CWFP as a priority policy for caries-reducing in Korean children and adolescents.

The potential use of bromelain as a natural oral medicine having anticarcinogenic activities.

Bromelain (BR), a protease extracted from Ananas comosus, reportedly possesses pharmacological activities including the reduction of thrombogenesis, and antihypertensive, and antimicrobial effects. This study aimed to investigate the potential effects of BR on oral cancer cells. The effect of BR on the viability of Ca9-22 and SCC25 cells was determined using the MTT assay. These cells were also treated with different doses of BR, and Western blotting was conducted to monitor apoptosis. Finally, flow cytometry analysis was performed to identify sub-G1 populations of oral cancer cells. After treatment, the viability of both Ca9-22 and SCC25 cells was markedly reduced, in a dose-dependent manner. BR induced poly (ADP-ribose) polymerase (PARP) and lamin A/C degradation, and generated cleavage products. Flow cytometry analysis showed that BR treatment significantly increased the sub-G1 population. Our findings therefore indicate that BR has potential as a novel, natural anticarcinogenic medicine.