Yoko Kawaguchi

Clinical trial of oral malodor treatment in patients with periodontal diseases

BACKGROUND AND OBJECTIVE Only a few clinical research studies have assessed different therapeutic approaches to oral malodor in subjects affected by periodontal diseases. The aim of this study was to evaluate the effects of periodontal treatment and tongue cleaning on oral malodor parameters in periodontitis and gingivitis patients. MATERIAL AND METHODS The subjects were 102 periodontitis and 116 gingivitis patients with oral malodor. Oral malodor was measured by organoleptic test and Oral Chroma™. Oral health status, including tooth conditions, periodontal health, tongue coating and proteolytic activity of the BANA test in tongue coating were assessed. Subjects in each periodontal disease group were randomly assigned into two subgroups depending on the sequence of treatment: periodontal treatment and tongue cleaning. Oral malodor and oral health parameters were compared by groups and sequence of treatment. RESULTS For subjects in the periodontitis group, there were statistically significant reductions in oral malodor after periodontitis treatment or tongue cleaning; however, major reductions were found after periodontitis treatment. For those in the gingivitis group, there were also statistically significant reductions in oral malodor after gingivitis treatment or tongue cleaning, but the most marked reductions were observed after tongue cleaning. At the completion of treatment, all oral malodor parameters fell below the threshold levels in all subgroups. CONCLUSION The present study indicated that periodontal treatment played an important role and tongue cleaning contributed to a lesser extent to reduction in oral malodor in periodontitis patients. In contrast, tongue cleaning alone can be the primary approach to reduce oral malodor in gingivitis patients.

Effects of a mouthwash with chlorine dioxide on oral malodor and salivary bacteria: a randomized placebo-controlled 7-day trial

BackgroundPrevious research has shown the oxidizing properties and microbiological efficacies of chlorine dioxide (ClO2). Its clinical efficacies on oral malodor have been evaluated and reported only in short duration trials, moreover, no clinical studies have investigated its microbiological efficacies on periodontal and malodorous bacteria. Thus, the aim of this study was to assess the inhibitory effects of a mouthwash containing ClO2 used for 7 days on morning oral malodor and on salivary periodontal and malodorous bacteria.Methods/DesignA randomized, double blind, crossover, placebo-controlled trial was conducted among 15 healthy male volunteers, who were divided into 2 groups. Subjects were instructed to rinse with the experimental mouthwash containing ClO2 or the placebo mouthwash, without ClO2, twice per day for 7 days. After a one week washout period, each group then used the opposite mouthwash for 7 days. At baseline and after 7 days, oral malodor was evaluated with Organoleptic measurement (OM), and analyzed the concentrations of hydrogen sulfide (H2S), methyl mercaptan (CH3SH) and dimethyl sulfide ((CH3)2S), the main VSCs of human oral malodor, were assessed by gas chromatography (GC). Clinical outcome variables included plaque and gingival indices, and tongue coating index. The samples of saliva were microbiologically investigated. Quantitative and qualitative analyses were performed using the polymerase chain reaction-Invader method.Results and DiscussionThe baseline oral condition in healthy subjects in the 2 groups did not differ significantly. After rinsing with the mouthwash containing ClO2 for 7 days, morning bad breath decreased as measured by the OM and reduced the concentrations of H2S, CH3SH and (CH3)2S measured by GC, were found. Moreover ClO2 mouthwash used over a 7-day period appeared effective in reducing plaque, tongue coating accumulation and the counts of Fusobacterium nucleatum in saliva. Future research is needed to examine long-term effects, as well as effects on periodontal diseases and plaque accumulation in a well-defined sample of halitosis patients and broader population samples.Trial registrationClinicalTrials.gov NCT00748943

Relationship of smoking and smoking cessation with oral health status in Japanese men

BACKGROUND AND OBJECTIVE Smoking has been associated with the number of natural teeth a person has and with the likelihood of periodontitis. The purpose of this study was to determine the relationships between the number of teeth present and periodontal diseases with smoking habits in a cohort of Japanese men. MATERIAL AND METHODS The study group comprised 1088 men, 40-75 years of age. Oral examinations were conducted in dental clinics. Information on smoking status and on oral health behavior was collected from self-administered questionnaires. The relationship between oral health status and smoking status was estimated using adjusted odds ratios. RESULTS Compared with those whom had never smoked, the odds ratios of having more than eight missing teeth and having periodontitis, among current smokers, were 1.67 and 1.74, respectively. In those who had stopped smoking for 11 years or longer, there was no increase in the odds ratio of having more than eight missing teeth and periodontitis, compared with those whom had never smoked. CONCLUSION Smoking has a positive association with missing teeth and periodontitis. However, smoking cessation is beneficial for oral health. The odds of having more than eight missing teeth, or of having periodontitis, in those who had never smoked was similar to that of individuals who reported that they had stopped smoking for 11 years or more.

A randomized double blind crossover placebo-controlled clinical trial to assess the effects of a mouthwash containing chlorine dioxide on oral malodor

BackgroundPrevious research has shown the oxidizing properties and microbiological efficacies of chlorine dioxide (ClO2), however, its clinical efficacies on oral malodor have been evaluated only with organoleptic measurements (OM) or sulphide monitors. No clinical studies have investigated the inhibitory effects of ClO2 on volatile sulfur compounds (VSCs) using gas chromatography (GC). The aim of this study was to assess the inhibitory effects of a mouthwash containing ClO2 on morning oral malodor using OM and GC.MethodsA randomized, double blind, crossover, placebo-controlled clinical trial was conducted among 15 healthy male volunteers, who were divided into 2 groups. In the first test phase, the group 1 subjects (N = 8) were instructed to rinse with the experimental mouthwash containing ClO2, and those in group 2 (N = 7) to rinse with the placebo mouthwash without ClO2. In the second test, phase after a one week washout period, each group used the opposite mouthwash.Oral malodor was evaluated before rinsing, right after rinsing and every 30 minutes up to 4 hours with OM, and concentrations of hydrogen sulfide (H2S), methyl mercaptan (CH3SH) and dimethyl sulfide ((CH3)2S), the main VSCs of human oral malodor, were evaluated with GC.ResultsThe baseline oral condition in the subjects in the 2 groups did not differ significantly. The mouthwash containing ClO2 improved morning bad breath according to OM and reduced concentrations of H2S, CH3SH and (CH3)2S according to GC up to 4 hours after rinsing. OM scores with ClO2 were significantly lower than those without ClO2 at all examination times. Significant reductions in the concentrations of the three kinds of VSCs measured by GC were also evident at all examination times. The concentrations of the three gases with ClO2 were significantly lower than those without ClO2 at most examination times.ConclusionIn this explorative study, ClO2 mouthwash was effective at reducing morning malodor for 4 hours when used by healthy subjects.Trial registrationClinicalTrials.gov NCT00655772

Lotka's law and the pattern of scientific productivity in the dental science literature

Statistical regularities can be observed in many natural and social phenomena. From empirical data on the authorship of scientific papers, Lotka deduced an inverse-square law: the number of authors publishing n papers is 1/n2 of those publishing one paper. The general type for the relation (1/n(c)) has a wide range of applicability to a variety of phenomena. This study examined, by means of bibliometric tools, whether Lotkas law could be applied to the literature of dental science. Data came from 20 leading dental science journals, as reported in Journal Citation Reports. The search was performed with a programme developed using Visual Basic for Applications, which counted the number of authors and analysed their contributions to the literature. Authorship for all contributions, as reported in Medline, was compiled for each of these 20 journals for the last 25 years, 1971 through 1995. The total number of authors was 43,796, responsible for 124,556 authorships. The journals published in countries other than the USA exhibited higher degrees of author concentration. The dental science literature conformed very well to Lotkas model with c = 1.95.

Relationship of smoking and smoking cessation with number of teeth present: JPHC Oral Health Study*

BACKGROUND Smoking is associated with the number of teeth. The purpose of this study was to determine the relationship of number of teeth with smoking and smoking cessation. METHODS Subjects included 547 males aged between 55 and 75 years. Oral examinations were conducted in 2005. Smoking status information was collected from questionnaire surveys conducted in 1990, 1995, 2000, and 2005. The relationship between having more than eight missing teeth and smoking status was estimated with adjusted odds ratio. RESULTS Comparing with never smokers, odds ratios of having more than eight missing teeth among current and former smokers were 1.96 and 1.86, respectively. The odds ratios in those who had stopped smoking for <or=10 years was 3.02, and for those who had ceased smoking for 11-20 years was 2.66. In those who stopped smoking for 21 years or more, there was no increase in the odds ratio. CONCLUSION Smoking had a positive association with the number of missing teeth and smoking cessation is beneficial for maintaining teeth. The odds of having more than eight missing teeth in those who had never smoked was equal to that of individuals who reported that they had stopped smoking for 21 years or more.

Oral Malodor and Related Factors in Japanese Senior High School Students

BACKGROUND Oral malodor (halitosis or bad breath) might be an important motivation tool for improving oral health in adolescents. There are few studies that report the epidemiology of oral malodor in high school students and the relationships with lifestyle and oral health status. This research was conducted to obtain underlying data for introducing an oral health education program which targeted prevention of oral malodor as a motivation tool for changing oral health behavior in high school students. METHODS A questionnaire, school oral examination, and oral malodor measurement were conducted on senior high school students in a Tokyo metropolitan school in 2007. A total of 474 students (male: 219, female: 255) were used for the analysis. RESULTS Over 42% of subjects reported that they had experienced anxiety, or were conscious of oral malodor, on at least 1 occasion. The students who had detectable oral malodor comprised 39.6% of subjects. The binary logistic regression analyses showed that whether or not subjects ate breakfast before the oral examination (p < .05), the presence of plaque (p < .01), and presence of a substantive tongue coating (p < .01) were related to the presence of detectable oral malodor. CONCLUSIONS Cleaning the oral cavity and eating breakfast are important to prevent oral malodor in high school students. This study indicated that school health education incorporating prevention of oral malodor as a motivation tool for oral health promotion could be a valuable procedure to include in high school dental health education programs.

Oral health status and chewing ability is related to mini-nutritional assessment results in an older adult population in Thailand.

In a cross-sectional study, we investigated the relationship of Mini-Nutrition Assessment (MNA) results with chewing ability tests and oral examinations (number of teeth present and functional tooth units (FTUs)). The participants were 612 older people (Mean [SD] age: 68.8 [5.9]). According to the MNA score, 25.1% of participants were categorized as having normal nutrition, 67.2% were categorized as at risk of malnourishment, and 7.7% were categorized as having malnutrition. The mean numbers of teeth present and FTUs were [15.5] and [8.9], respectively. The ANCOVA analyses adjusted for age and gender showed that participants with malnutrition had lower numbers of teeth present (8.8), FTUs (8.4), and chewing ability (6.8) than those with normal nutrition (13.3, 10.4 and 7.8) (p < 0.05). Nutritional status was associated with mean numbers of teeth present, FTUs, and chewing ability. Therefore, it was concluded that retention of natural teeth with appropriate numbers of FTUs by replacing missing teeth with dentures and improving chewing ability will help the reduce risk of malnutrition in older adults.

Clinical oral malodor measurement with a portable sulfide monitor

OBJECTIVE The aim of this study was to evaluate the clinical ability of Breathtron by comparing it with other malodor measurement procedures: the organoleptic test (OT) and gas chromatography (GC). SUBJECTS AND METHODS Patients were 475 patients who visited a fresh breath clinic. Oral malodor was measured with the OT, GC, and Breathtron. Correlation analysis and two linear regression analyses were conducted to examine the relationship of the Breathtron values with OT scores and volatile sulfide compound (VSC) concentrations by GC: i.e. the regression of Breathtron on OT and the regression of Breathtron on total VSCs by GC. Receiver operating characteristics (ROC) analysis was conducted to investigate the sensitivity and specificity of Breathtron. RESULTS The Breathtron values were significantly correlated with OT and VSCs by GC. In the regression analysis, predicted Breathtron values were 199.3 and 520.1 ppb for OT scores 1 and 2, and reasonably close to total VSCs by GC between 550 and 750 ppb. The ROC analysis demonstrated that Breathtron is a useful and valuable adjunct measurement tool. CONCLUSIONS Breathtron is a simple, rapid and reliable appliance for screening oral malodor if an appropriate malodor threshold level is chosen.

Degradation of MUC7 and MUC5B in human saliva.

Background Two types of mucins, MUC7 and MUC5B constitute the major salivary glycoproteins, however their metabolic turnover has not been elucidated in detail to date. This study was conducted to examine turnover of MUC7 and MUC5B in saliva, by focusing on the relationship between their deglycosylation and proteolysis. Methodology/Principal Findings Whole saliva samples were collected from healthy individuals and incubated at 37°C in the presence of various protease inhibitors, sialidase, or a sialidase inhibitor. General degradation patterns of salivary proteins and glycoproteins were examined by SDS-polyacrylamide-gel-electrophoresis. Furthermore, changes of molecular sizes of MUC7 and MUC5B were examined by Western blot analysis. A protein band was identified as MUC7 by Western blot analysis using an antibody recognizing an N-terminal epitope. The MUC7 signal disappeared rapidly after 20-minutes of incubation. In contrast, the band of MUC7 stained for its carbohydrate components remained visible near its original position for a longer time indicating that the rapid loss of Western blot signal was due to the specific removal of the N-termimal epitope. Pretreatment of saliva with sialidase facilitated MUC7 protein degradation when compared with samples without treatment. Furthermore, addition of sialidase inhibitor to saliva prevented proteolysis of N-terminus of MUC7, suggesting that the desialylation is a prerequisite for the degradation of the N-terminal region of MUC7. The protein band corresponding to MUC5B detected in both Western blotting and glycoprotein staining showed little sign of significant degradation upon incubation in saliva up to 9 hours. Conclusions/Significance MUC7 was highly susceptible to specific proteolysis in saliva, though major part of MUC5B was more resistant to degradation. The N-terminal region of MUC7, particularly sensitive to proteolytic degradation, has also been proposed to have distinct biological function such as antibacterial activities. Quick removal of this region may have biologically important implication.