This study was performed to investigate the relationship between oral health behavior and dental caries prevalence in middle-aged adults. The subjects were 808 employees (589 males and 219 females, aged 35 years and over) who worked at a dental products company. A questionnaire called the Dental Checker® (Ver. 1) with four scales of dental health knowledge, attitudes, behavior and perceived oral conditions was self-administered. Their dental conditions (DT, MT, FT and DMFT) were examined by one dentist. The scoring system of oral health behavior was based on subjects' answers. Cronbach's alpha scores for Knowledge, Attitudes, Behavior and Perceived oral health were 0.39, 0.58, 0.73 and 0.64, respectively. When the associations of the DT with five variables including Age were studied by multiple regression analysis, DT was negatively associated with Attitudes and Perceived oral health (p<0.001, p<0.05, respectively). FT was negatively associated with Age (p<0.01), and positively with Attitudes (p<0.001). MT was negatively associated with Perceived oral health and positively with Age (p<0.001). DMFT was predicted to some extent by the Dental Checker® (p<0.001). The four behavioral scales were significant oredictors of DMFT. whereas Age did not have any association with DMFT.
Since 1995, the Dental Health Examination at Japanese institutions of instruction (from Kindergartens to universities) has come to include one new category, "CO", meaning that there are apprehensions that caries will evolve on specific teeth of students. However, ever since the new "CO" category was established, there has been insecurity in diagnoses by dentists about what teeth should be judged to have "CO" characteristics, i. e., how to distinguish "CO" from both states of "no defects" and of "caries positive." The purpose of this investigation is to understand the standards of judgement applied by dentists performing "C0"-examinations. We collected 16 molar teeth samples extracted from patients under dental treatment, plugged them into a plastermodel and asked 95 different dentists to pass, within 2 minutes, judgement concerning the states of pit and fissure caries with verdicts of "CO" or "no defects." Inspection of the 16 molar teeth samples showed that the 95 dentists found an average of 3.37 teeth that they considered as "CO." One dentist diagnosed 12 of the tooth samples as being within the "CO" category. Twelve of the dentists did not classify any of the 16 teeth as showing "CO"-features, because they concluded that all teeth were either without problems or had heavier defects. After having obtained these diagnoses from the dentists, the 16 tooth samples were sliced and subjected to examination by means of microscopy. The official definition of "CO" implies an "absence of dental cavities accompanied by changes of tooth surface and color." Microscopy and the application of this official measure revealed that 3 out of the 16 teeth should have been diagnosed as exhibiting "C0"-characteristics. Five of the teeth should have been evaluated as being inflicted by caries. These observations show that in the Dental Health Examination at Japanese institutions of instruction, personal judgement of examining dentists can exhibit considerable variations. Such variations of instant judgement of dentists in diagnosing "C0"-characteristics of teeth of pupils or students, of course, will be reflected in inaccuracies in the official statistics.
The purpose of this study was to evaluate the masticatory abilities in adults. The number of examinees was 273 male adults aged from 24 to 53 years old in Hokkaido. For this study, we measured the amount of sugar elution per second from chewing gum in each examinee, and asked them to answer a questionnaire with 4 categories and 25 foods for objective and subjective evaluation. To examine the relationship between objective and subjective evaluation of masticatory function, we analyzed the relationship between objective and subjective evaluation using three factors, the number of present teeth, occlusal area, and occlusal force, as a basis. The result of objective evaluation of masticatory function was that the amount of sugar elution per second decreased with reduction of each value of the factors. In subjective evaluation of masticatory function, it became difficult for subjects to chew hard foods with decreases in each value of the factors. It was suggested that there were some relationships between objective and subjective evaluation.
The aim of this study was to analyze the effect of stabilized occlusion on feeding functions of bedridden elderly individuals. The subjects were 73 individuals (22 males and 51 females, mean age of 83.8, 8.2 SD) in a nursing home. Evaluation methods used included a questionnaire covering daily life activities, total body functions and diet, and a clinical examination. The factors affecting feeding functions were analyzed by x^2 test. Dentists and dental hygienists examined oral conditions and feeding functions by RSST and the food test. We analyzed the relationships among stabilized occlusion, RSST and the food test. The results obtained were as follows. 1. The results of RSST demonstrated that 17 of 57 (29.8%) individuals exhibited dissatisfactory function for swallowing (less than 3 times/30 seconds). This dissatisfaction rate was significantly higher in the individuals without stabilized occlusion as compared to the ones with stabilized occlusion (p<0.01). 2. Sixteen of 57 (28.1%) individuals took more than 5 seconds until the first swallowing was completed in the RSST. This unfavorable phenomenon was prominent in the individuals without stabilized occlusion as compared to the ones with stabilized occlusion ; however, no statistical differences existed between them. 3. Food remaining was detected in 40 of 69 (58.0%) individuals in the food test. The subjects with stabilized occlusion demonstrated significantly less food remaining as compared to the ones without stabilized occlusion (p<0.01).
Halitosis, or bad breath, is a common presenting complaint of adult dental patients. "Real" halitosis usually originates from putrefactive oral microbial activity caused by poor dental hygiene or dental diseases such as periodontitis. However, halitosis is occasionally imagined by oneself and not detectable by others. Recently, reports about halitophobia have increased in Japan. Halitophobia patients complain of having bad breath, but which no-one else can smell, and for which no local or systemic cause can be found. Many studies about halitosis to date have been by biomedical, clinical, and psychosomatic medical approaches, and few studies have been performed behavioral-scientifically. The purpose of the present investigation was to search for the risk factors for halitophobia in high school students. A total of 529 high school students aged between fifteen to nineteen were surveyed in May 1997. Questionnaires consisted of 29 items including bad breath, health behavior, daily habits, and subjective factors concerning the symptoms for oral health conditions. One hundred twenty-five randomly selected students were examined for PMA and DI-S in a school dental check-up, and the relationship between the oral conditions and consciousness of bad breath was analyzed. Data were analyzed by Mann-Whitney's U test, Fisher's exact test and Spearman's correlation coefficient by rank. The rate of students often complaining of their own bad breath was 11.4%, and there was no difference between sexes. Students anxious about their bad breath during conversation comprised 46.7%, and females tended to be more nervous about their own and other's bad breath than males. It seemed that females had a tendency to be excessively conscious of bad breath. It was also suggested statistically that students who were aware of their bad breath during conversation had intensive consciousness of oral conditions, i. e., toothache by sweeteners or cold stimulation, and xerostomia. A significant relationship was noted between self-consciousness of bad breath and oral conditions in males but not in females. PMA and DT scores of students with intensive consciousness of their bad breath were significantly lower than that of those who sometimes complained of having bad breath. In conclusion, high school female students were more conscious of having bad breath than males, and intensive interest in one's own oral conditions mav be an important risk factor for halitophobia.
Acid resistance of remineralized subsurface enamel lesions after exposed various concentrations of sodium bicarbonate solutions was studied in vitro. In this study, extracted healthy premolars from subjects aged 10-14 years (the mean age was 11.9 years) by reason of orthodontics were used. Subsurface lesions were produced by a 3 days of immersion in demineralizing solution of 0.1 M lactic acid containing 3.0 mM Ca and 1.8 mM P adjusted to pH 5.0 at 37℃. The subsurface lesions were exposed to a remineralizing solution containing the same amounts of Ca and P and 2 ppm F at pH 7.0 and 37℃ for 9 days. During the remineralization period, the lesions were immersed in 4 different concentrations of sodium bicarbonate solutions (0.0, 0.5, 5.0, and 50.0 mM/l) for 30 min twice a day. Two kinds of bicarbonate solutions (5.0 mM/l and 50.0 mM/l) corresponded to the concentrations of bicarbonate ions in resting whole saliva and stimulated whole saliva, respectively. After remineralization, the acid resistance of lesions was tested by immersion in demineralizing solution at pH 5.0 and 37℃ for 3 days. They were sectioned in slices of about 100 μm, and examined by contact microradiography. Subsequently, the mineral profiles of each section were drawn. The results showed that the groups of sodium bicarbonate solution challenged during remineralization were more acid resistant than the groups not challenged at the inner zone of the subsurface lesion (p < 0.05). It seemed that the reasons for this were mainly due to the inhibition of pH drop in the lesions by consuming H^+ ions derived from the acid with NaHCO3 that penetrated and remained in the lesions. However, there was no acid resistance difference among the concentrations of sodium bicarbonate solutions.
Zinc-deficiency that causes dysgeusia was investigated in this study by examining the influences on amount of voluntary running activities and zinc content of tissue zinc. Donryu rats aged four weeks were used in this study. The rats were divided into groups of running activity and no running activity, and each of the groups was further divided into a control group, zinc-deficient group and zinc-deficient group. The rats were raised for four weeks under determined conditions of each group ; some rats were treated by zinc supplementation in the last two weeks. The animals were decapitated at four weeks and such levels as Ht, Hb, blood index, content of tissue zinc were examined. The following results were obtained I 1. It was demonstrated that zinc-deficiency had more serious influences on growth of animals than their voluntary running activity. 2. The Hb value didn't change but the Ht value increased in the zinc-deficient group. A color index reduction that affected the MCHC value was observed in the zinc-deficient group. However, all the changes in blood showed no relations to voluntary running activities. 3. Zinc content and alkaline phosphatase activity in tissue and serum decreased, but also showed no relations to voluntary running activities. Zinc content in liver and kidney recovered soon after zinc supplementation treatment. 4. It was also discovered that zinc content distributed in the root of the tongue was significantly low in the zinc-deficient group in comparison with the control group. 5. The amount of voluntary running activities in zinc-deficient rats was less than that of the control group rats, but an increasing tendency was observed after zinc supplementation treatment.
Gingival crevicular fluid (GCF) contains various biological materials that could reflect microbial challenge and the host response in periodontal tissue. We investigated the utilization of laboratory tests that could analyze many biochemical materials in many samples of GCF obtained in the workplace. We employed 12 biochemical tests of GCF: hemoglobin, albumin, transferrin, α_1-antitrypsin, IgG, IgA, IgM, fibronectin, PMN-elastase, myeloperoxidase, lactoferrin and lysozyme. We also employed 7 periodontal tests: supragingival plaque, gingival inflammation, pocket depth, attachment loss, dental calculus, bleeding on probing and loss of alveolar bone. GCF was taken from 93 periodontal sites of 32 workers. Each variable of the biochemical tests showed significant correlations with more than one variable of the periodontal tests. In total, significant and positive correlations were found in 26 sets of the biochemical and periodontal variables. Principal component analysis of biochemical tests extracted two principal components, and each score of the components was correlated significantly with three periodontal variables. Factor analysis using all variables computed two groups of the biochemical tests apart from three groups of the periodontal tests. These results suggest that selection or integration of biochemical variables could estimate periodontal condition and that information of biochemical tests may be different from that of periodontal tests, and thus indicate that laboratory tests of GCF in the workplace could offer various information for periodontal health of workers.
The purpose of this study was to evaluate and compare three diagnostic methods in detecting early caries in occlusal surfaces. Three different methods, namely, visual inspection (VI), electrical caries monitor (ECM) and a caries detector dye (Dye) were used to diagnose occlusal caries in extracted teeth. One hundred sixty-one sites in a total of 42 extracted teeth were examined by three examiners with VI and ECM methods, whereas the Dye method to detect caries was tested by only one examiner. Histological examination of the teeth served as a validating criterion to evaluate the ability of each method to diagnose caries. Of 161 sites, 82, 96 and 96 sites were diagnosed as having caries by the VI, ECM and Dye methods, respectively, compared with 85 sites by histological validation. ECM showed the highest level in sensitivity (85%), followed by VI (67%) and Dye (63%). In the ROC analysis, the areas under ROC reached 0.73, 0.89 and 0.61 for the VI, ECM and Dye methods, respectively. The kappa values ranged from 0.64-0.80 and 0.75-0.82 in intra- and inter-examiners for ECM, respectively, and between 0.53-0.82 and 0.29-0.70 for VI. It was concluded that the ECM method is more valid and reproducible than VI or Dye for the diagnosis of occlusal caries.
The strategy and methods of annual dental health examinations at school were changed in 1995. Accordingly, the style of the dental health examination card was changed and observation of dental caries (CO) and gingivitis (GO) were introduced. Also, the importance of follow-up after the examination was emphasized. However, the results of dental health examinations at school are not always utilized effectively. In order to effectively utilize the dental health examination at school for dental health education, it is necessary to know how well students understand the diagnosis of the examination. The purpose of the study was to investigate how well students understand the diagnosis of annual dental health examinations. First-year senior high school students from two schools participated in the study. The questionnaire was designed to elicit information with respect to the cognition of the diagnosis of dental health examination by the students. The records of annual dental health examinations were also utilized. It was found that 95.6% of the students who had dental caries understood they had cavities. On the other hand, only 42.0% of the students understood that they had been diagnosed with gingivitis and 44% answered that they didn't understand the significance of the diagnosis. Among the students who were advised to visit a dental office for treatment, 44.3% and 55.9% received treatment for dental caries and gingivitis, respectively. It was speculated that low cognition of gingivitis by senior high school student was caused by the lack of health education on periodontal disease at elementary school or junior high school. Moreover, contents of the written notice of dental treatment are not effective for the students to understand their own oral health conditions. Since senior high school students seemed to be unaware of their periodontal diseases, it was suggested that dental health education to prevent periodontal disease is necessary for high school students.
Fluoride is a trace element important for the prevention of dental caries. Aluminum absorption is thought to be one of the riskfactors in Alzheimer's disease. Both elements are abundant in foods and pharmaceuticals. It is important to assess the bioavailability of each element when ingested together due to the strong chemical affinity of fluoride and aluminum. The objectives of the present study are: 1) to examine the interaction of fluoride and aluminum in the time course of gastrointestinal absorption of both elements; and 2) to determine the possible effects of various fluoride to aluminum ratios, relative to absorption of each and serum transferrin binding of aluminum in rats. The results indicate that fluoride increases the gastrointestinal absorption of aluminum, while aluminum decreases the absorption of fluoride in rats. The mechanism of these effects may be related to the formation of A1F3 complex. The results also indicate that fluoride reduces the ratio of transferrin-bound aluminum to total aluminum in serum, both in vivo and in vitro.
Objects I The aim of this study was to assess the subjective oral health status of the general population. Methods : Data were collected by means of a mail survey and self-administered questionnaire of a random sample of the general population aged 40-69 years. The items of subjective indicators consisted of two types of scales I 1) perceived dental health, 2) disability by oral pain and limitation. Of 2001 questionnaires mailed, 1,389 (69%) were returned. Results : Of 1,230 who completed the questionnaires, 44% reported that perceived dental health was fair or poor, compared with 26% for perceived general health. In gender and age groups, there were differences in the proportion of "Oral pain," "Functional limitation" or "Social limitation" reported. Eight% reported that these oral problems affected their daily lives considerably. Conclusion : It is impossible to reflect need and satisfaction for dental care simply with objective measures. Subjective oral health measures in addition to objective measures may be useful in clarifying the oral health status of the general population.
FSPD-34, as a questionnaire to comprehensively diagnose periodontal disease at a worksite, was developed. It was based on the PRECEDE-PROCEED model. The questionnaire consists of 6 subscales that are mutually related. They comprise the sub-scale of QOL, self-assessment of periodontal disease, oral health behavior, predisposing factors, reinforcing factors and enabling factors. The purpose of the present study was to evaluate internal and test-retest reliability. Subjects were 324 factory workers aged between those in their 20s and those in their 60s who completed a questionnaire. Internal reliability of QOL and self-assessment of periodontal disease sub-scales were high (Cronbach's alpha, 0.70-0.79). However, those of other sub-scales were low. Seventy-six were selected from all subjects by systematic sampling for test-retest reliability. All sub-scales demonstrated good test-retest reliability (r = 0.68-0.83). However, the questionnaire should be improved, because some sub-scales demonstrated low internal reliability on a further investigation.
The periodontal health status of middle school students participating in a preventive program for gingivitis, which had been performed in a middle school since 1993, is evaluated in this paper. The program consisted of instruction in appropriate oral hygiene procedures to 7 th grade (12-year-old) students and recommendations to all 7 th-9 th grade students with a CPI (Community Periodontal Index) Code 2 and higher to receive oral hygiene instruction and professional care at private dental clinics. The subjects comprised 111 (58 boys; 53 girls) students who had entered middle school in 1993. When the periodontal health status was assessed annually and longitudinally, it was shown that the mean number of healthy sextants increased and the mean number of sextants with bleeding on probing decreased in 9 th grade students more significantly than those in 7 th or 8 th grade. When compared with the baseline status of 9 th grade students in 1993, both the percentage of students and the mean numbers of sextants with Code 2 (calculus) or Code 3 (4-5 mm pockets) and sextants with bleeding on probing were significantly lower in the 9 th grade students in 1995. Consequently, the improvement of their periodontal health status might be substantially attributed to the preventive program that had been specially designed and performed to control gingivitis in middle school students.
The present research was undertaken to study the reliability of dental health questionnaires used on the Internet. The subjects were 1,037 Internet users who accessed the WWW site we uploaded for research and 777 T village in habitants who answered the same questions on paper. The questionnaire contained 10 items about lifestyle and oral conditions. These items were selected from the study of T village according to their importance in retained teeth. Each item had a different score, and the total was 20. The results were summarized as follows. 1. The investigation by the Internet was able to obtain a sufficient number of subjects in a short period. 2. The number of respondents to the Internet investigation was proportional to the area population of the whole country, and the male-to-female ratio was approximately equal. 3. Most of the respondents of the Internet investigation were from approximately 20 to 60 years old. 4. The score of the paper questionnaire used in T village and the Internet investigation showed the same distribution. Therefore, the Internet investigation was adequate for statistical analysis. 5. The answers of the Internet investigation appear to have been given with the understanding of the respondents. It was concluded that an Internet investigation was an investigating method that has usefulness and reliability for dental study.