Influence of carbonated drinks on acid production in Streptococcus mutans biofilm / 대한구강보건학회지

Objectives@#The purpose of this study was to determine the influence of carbonated drinks on acid production in Streptococcus mutans biofilm. @*Methods@#Fifty one hour-old S. mutans biofilms were formed on hydroxyapatite discs. After selecting of the carbonated drinks (Coca cola, Coca cola zero sugar, Sprite, Sprite zero sugar, and Fanta), as well as negative (water) and positive (1% sucrose) controls for this study, glycolytic pH drop assay was performed using the S. mutans biofilms. The influence of the test agents on acid production of the 51 h-old biofilms was determined by the initial production rate and final concentration of protons, calculated using the pH values at 0-30 min and 120 min, respectively. @*Results@#The pH values of the carbonated drinks ranged from 2.4 to 3.1. Sugar-free carbonated drinks and the negative control maintained the pH of acid produced by S. mutans biofilms above the critical pH. The sugar-added carbonated drinks and the positive control decreased the pH below the critical pH due to the acid production of S. mutans biofilms. Overall, sugar concentration in carbonated drinks was closely related to acid production in S. mutans biofilm. @*Conclusions@#These results suggest that sugar-added carbonated beverages should be considered for their role in dental erosion and dental caries, while non-sugar-added carbonated beverages should emphasize their role in dental erosion rather than dental caries.

The effect of socio-psychological trait on the oral health related quality of life among college students / 대한구강보건학회지

Objectives@#The purpose of this study was to examine the association between oral health-related quality of life and adult attachment type among college students. @*Methods@#A total of 557 self-administered questionnaires were collected from undergraduates in Jeonbuk. Data were analyzed using SPSS 22.0. The results were analyzed using t-tests, analyses of variance, Duncan’s multiple range tests, correlation analyses, and multiple regression analyses. @*Results@#The results of this study showed that sex and age were significant factors according to the analysis of the oral health-related quality of life in terms of general characteristics. The variable that had the greatest effect on the oral health-related quality of life was attachment anxiety, followed by age, sex, and attachment avoidance. @*Conclusions@#Education and counseling to promote safety of adult attachment will improve the oral health-related quality of life for college students.

The effect of socio-psychological trait on the oral health related quality of life among college students / 대한구강보건학회지

Objectives@#The purpose of this study was to examine the association between oral health-related quality of life and adult attachment type among college students. @*Methods@#A total of 557 self-administered questionnaires were collected from undergraduates in Jeonbuk. Data were analyzed using SPSS 22.0. The results were analyzed using t-tests, analyses of variance, Duncan’s multiple range tests, correlation analyses, and multiple regression analyses. @*Results@#The results of this study showed that sex and age were significant factors according to the analysis of the oral health-related quality of life in terms of general characteristics. The variable that had the greatest effect on the oral health-related quality of life was attachment anxiety, followed by age, sex, and attachment avoidance. @*Conclusions@#Education and counseling to promote safety of adult attachment will improve the oral health-related quality of life for college students.

Chronologic trends of cancer-related lymph node research in PubMed: informetrics analysis

Purpose@#Given the long history of investigation into cancer and its relevance to the lymph node (LN), it would be meaningful to plot the trends of research on cancer-related LN. @*Methods@#Queries such as “cancer,” “lymph node,” and “cancer and lymph node” were submitted to PubMed to collect articles on cancer and LN published between 1945 and 2017. The collected articles were then extracted by an automatic web crawler and examined through informetrics and linguistic analysis. @*Results@#The number of articles related to cancer was 2,795,476 and 127,897 articles (4.6%) were found to be relevant to LN. With regard to cancer types, breast cancer was the most studied (37%), followed by gastric cancer (17%). With regard to the subjects in which the surgeon is interested, LN metastasis (57%) was found to be the topic most discussed, followed by LN dissection (22%) and sentinel LN (17%). Publications on LN metastasis gradually increased over time from 1988 to 2017 although those on sentinel LN and LN dissection have stagnated since the early 2000s. @*Conclusion@#Although research on cancer was abundant, only a small portion was dedicated to investigating its relevance to LN. Western countries had led the research on cancer-related LN, but Asian countries began to participate as major players, expanding their contributions. While LN metastasis, one of the major cancer-related LN topics, showed a steady increase, those involved in oncologic surgery such as LN dissection and sentinel LN did not.

Changes in the composition of artificial cariogenic biofilms over time / 대한구강보건학회지

OBJECTIVES: The purpose of this study was to investigate changes in the composition of artificial cariogenic biofilms using a Streptococcus mutans biofilm model over a period of time. METHODS: We analyzed the dry weight, colony forming unit (CFU) number, extracellular polysaccharide (EPS) biovolume, and acid production rate of S. mutans biofilms formed on saliva-coated hydroxyapatite discs after 26 h, 50 h, 74 h, 98 h, 171 h, and 195 h. In addition, we performed a laser scanning confocal fluorescence microscopy to determine the bacterial volume, EPS biovolume, and biofilm thickness. We calculated the biofilm density using dry weight and EPS biovolume. RESULTS: Over a period of time, there was no change in the CFU number and acid production rate of S. mutans biofilms, but there was an increase in the dry weight and EPS biovolume of S. mutans biofilms. The bacterial volume, EPS biovolume, and biofilm thickness only increased in the 50-h-old biofilm; however, no change was observed in 50-195-h-old biofilms. In addition, an increase in the biofilm density was observed over time. CONCLUSIONS: These results suggest that the acid production ability of cariogenic biofilms does not change, but the biofilm density increases over time. However, due to scientific information, further research needs to be conducted in the field of dentistry to get further insights on the progression of cariogenic biofilms over time.

Changes in public recognition of parabens on twitter and the research status of parabens related to toothpaste / 대한구강보건학회지

OBJECTIVES: The purpose of this study was to investigate changes in public recognition of parabens on Twitter and the research status of parabens related to toothpaste. METHODS: Tweet information between 2010 and October 2016 was collected by an automatic web crawler and examined according to tweet frequency, key words (2012-October 2016), and issue tweet detection analyses to reveal changes in public recognition of parabens on Twitter. To investigate the research status of parabens related to toothpaste, queries such as “paraben,”“paraben and toxicity,”“paraben and (toothpastes or dentifrices),” and “paraben and (toothpastes or dentifrices) and toxicity” were used. RESULTS: The number of tweets concerning parabens sharply increased when parabens in toothpaste emerged as a social issue (October 2014), and decreased from 2015 onward. However, toothpaste and its related terms were continuously included in the core key words extracted from tweets from 2015. They were not included in key words before 2014, indicating that the emergence of parabens in toothpaste as a social issue plays an important role in public recognition of parabens in toothpaste. The issue tweet analysis also confirmed the change in public recognition of parabens in toothpaste. Despite the expansion of public recognition of parabens in toothpaste, there are only seven research articles on the topic in PubMed. CONCLUSIONS: The general public clearly recognized parabens in toothpaste after emergence of parabens in toothpaste as a social issue. Nevertheless, the scientific information on parabens in toothpaste is very limited, suggesting that the efforts of dental scientists are required to expand scientific knowledge related to parabens in oral hygiene measures.

Logistic regression analysis of factors affecting the survival of central incisors in Korean adults / 대한구강보건학회지

OBJECTIVES: This study aimed to analyze the variables affecting the survival of the four permanent central incisors in an adult Korean population using logistic regression analysis. METHODS: The Korean government has been collecting oral health data at the national level at 3-yearly intervals since 2000. In addition, a national survey was conducted in 2006 of 15,777 persons aged 2 to 95 years old who were stratified by age, gender, and region. The raw data were input and the relationship between each of eight objective variables and tooth survival was analyzed by frequency, crosstabulation, and logistic regression analysis, with age, gender, and economic status as functional variables. The inclusion level was alpha=0.05 and the exclusion level was alpha=0.10. The eight variables were age, economic status (jobs), monthly family income, gender, frequency of toothbrushing per day, presence of diabetes, education level, and smoking years. RESULTS: The survival rate of the incisors decreased with an increase in age, while that in individuals who engaged in farming, stock breeding, and fishing was 5 to 7 times lower than that in individuals in top positions in terms of jobs and society. Further, the survival rate in individuals with diabetes was 2 to 3 times higher than in those without diabetes. CONCLUSIONS: The most significant predictor of the survival rate of the four permanent incisors in Korean adults was age, followed by economic status and presence of diabetes.

Logistic regression analysis of factors affecting survival of permanent second molars in Korean adults / 대한구강보건학회지

OBJECTIVES: The purpose of this study was to analyze the factors affecting the survival of permanent second molars in Korean adults using logistic regression analysis. METHODS: This National survey was conducted in 2006 and was performed in 3 stages comprising stratified sampling, age, sex, and region. This study included 15,777 persons, aged 2-95 years. The raw data was analyzed using SPSS software v12.0 and the relationship between the 9 variables and the tooth survival rate was analyzed by frequency and cross-tabulation. Logistic regression analysis using the functional weightage of the age, sex, regions of the Korean population was also performed. Entry was at level of 5%, while removal was at a 10% level during logistic regression analysis. The nine variables used for analysis were age, socio-economic level, monthly family income, sex, frequency of toothbrushing per day, diabetes, educational level, smoking, and frequency of snack intake per day. RESULTS & CONCLUSIONS: The most significant explanatory variables, in increasing order of significance, were age, socioeconomic status, and diabetes. As age increased by 10 years, the survival rate of second molars decreased at a slow rate 7.5% to 9.5%. The survival rate of the second molar of an individual engaged in activities, such as farming, stock breeding, and fishing decreased from 64.4% to 78.8% as compared to people at high positions in various companies and in society.

Erratum: Relationship between job competency, core self-evaluation, and job performance in dental hygienists / 대한구강보건학회지

The author's name was misspelled.

The Apoptotic Effect of the Hexane Extract of Rheum undulatum L. in Oral Cancer Cells through the Down-regulation of Specificity Protein 1 and Survivin / 한국실험동물학회지

The hexane extract of Rheum undulatum L. (HERL) has been shown to have anti-cancer activity in several cancers in vivo and in vitro. However, the anti-cancer activity of HERL and its molecular mechanism in human oral cancer cells has not been explored. Thus, the aim of this study was to elucidate the growth-inhibitory and apoptosis-inducing effects of HERL in HN22 and SCC15 oral cancer cell lines. This study shows that HERL inhibits oral cancer growth, decreases cell viability, and causes apoptotic cell death in HN22 and SCC15 cells, as characterized by morphological changes, nuclear condensation and fragmentation, the cleavage of PARP and the accumulation of cells in the sub-G1 phase. The treatment of oral cancer cells with HERL also resulted in decreased expression of specificity protein (Sp1) and its downstream protein, survivin. Therefore, our results suggest that the regulation of Sp1 and survivin plays a critical role in HERL-induced apoptosis in human oral cancer cells.

Influences of trans-trans farnesol, a membrane-targeting sesquiterpenoid, on Streptococcus mutans physiology and survival within mixed-species oral biofilms / 国际口腔科学杂志·英文版

Trans-trans farnesol (tt-farnesol) is a bioactive sesquiterpene alcohol commonly found in propolis (a beehive product) and citrus fruits, which disrupts the ability of Streptococcus mutans (S. mutans) to form virulent biofilms. In this study, we investigated whether tt-farnesol affects cell-membrane function, acid production and/or acid tolerance by planktonic cells and biofilms of S. mutans UA159. Furthermore, the influence of the agent on S. mutans gene expression and ability to form biofilms in the presence of other oral bacteria (Streptococcus oralis (S. oralis) 35037 and Actinomyces naeslundii (A. naeslundii) 12104) was also examined. In general, tt-farnesol (1 mmol x L(-1)) significantly increased the membrane proton permeability and reduced glycolytic activity of S. mutans in the planktonic state and in biofilms (P < 0.05). Moreover, topical applications of 1 mmol x L(-1) tt-farnesol twice daily (1 min exposure/treatment) reduced biomass accumulation and prevented ecological shifts towards S. mutans dominance within mixed-species biofilms after introduction of 1% sucrose. S. oralis (a non-cariogenic organism) became the major species after treatments with tt-farnesol, whereas vehicle-treated biofilms contained mostly S. mutans (>90% of total bacterial population). However, the agent did not affect significantly the expression of S. mutans genes involved in acidogenicity, acid tolerance or polysaccharide synthesis in the treated biofilms. Our data indicate that tt-farnesol may affect the competitiveness of S. mutans in a mixed-species environment by primarily disrupting the membrane function and physiology of this bacterium. This naturally occurring terpenoid could be a potentially useful adjunctive agent to the current anti-biofilm/anti-caries chemotherapeutic strategies.