Relationship between periodontal status and levels of glycated hemoglobin.

The objective of this study was to assess whether there is a bi-directional relationship between periodontal status and diabetes. Study 1 included 5,856 people without periodontal pockets of ≥ 4 mm at baseline. Relative risk was estimated for the 5-year incidence of periodontal pockets of ≥ 4 mm (CPI scores 3 and 4, with the CPI probe), in individuals with glycated hemoglobin (HbA1c) levels of ≥ 6.5% at baseline. Study 2 included 6,125 people with HbA1c < 6.5% at baseline. The relative risk was assessed for elevation of HbA1c levels in 5 years, with baseline periodontal status, assessed by CPI. Relative risk of developing a periodontal pocket was 1.17 (p = 0.038) times greater in those with HbA1c of ≥ 6.5% at baseline, adjusted for body mass index (BMI), smoking status, sex, and age. Relative risks for having HbA1c ≥ 6.5% at 5-year follow-up in groups with periodontal pockets of 4 to 5 mm and ≥ 6 mm at baseline were 2.47 (p = 0.122) and 3.45 (p = 0.037), respectively, adjusted for BMI, alcohol consumption, smoking status, sex, and age. The risk of developing periodontal disease was associated with levels of HbA1c, and the risk of elevations of HbA1c was associated with developing periodontal pockets of more than 4 mm.

Factors associated with Japanese dentists encouraging patients to use dental floss.

OBJECTIVE: The objective of this study was to clarify to what extent Japanese dentists recommend dental floss and what factors influence dentists in encouraging their patients to use dental floss. PARTICIPANTS: The subjects in this study were 291 dentists who were directors of dental clinics, selected by stratified sampling by age. RESULTS: Dentists whose teachers at dental school had demonstrated dental flossing tended to recommend patients to use dental floss 2.2 (1.0-4.6: 95% CI) times more frequently compared with those who did not see demonstrations of flossing at dental school. Respondents who considered that using dental floss was very easy and easy, moderate, and difficult recommended patients to use dental floss 45.4 (11.2-183.9), 17.4 (6.6-45.8) and 5.9 (2.5-14.1) times more frequently, respectively, compared with those who considered it very difficult. Respondents who considered that using dental floss was effective, fairly effective or very effective in preventing dental caries recommended patients to use dental floss 3.8 (1.7-8.6), 3.8 (1.7-8.8) and 9.1 (3.6-23.0) times more frequently respectively, compared with those who considered it ineffective or only slightly effective. CONCLUSIONS: The demonstration of the use of dental floss by teachers at their dental schools gave dentists a good impression and a positive opinion of dental flossing. This was closely associated with recommendations by dentists to their patients to use dental floss.

Five-year incidence of periodontal disease is related to body mass index.

Numerous cross-sectional epidemiological studies suggest that obesity is associated with periodontal disease. This longitudinal study tested whether body mass index (BMI) was related to the development of periodontal disease in a sample of employed Japanese participants. Data are from the statutory medical checkups routinely collected for employees in and around Nagoya, Japan. The authors tested the relationship between BMI at baseline and the 5-year incidence of periodontal disease in a sample of 2787 males and 803 females. The hazard ratios for developing periodontal disease after 5 years were 1.30 (P < .001) and 1.44 (P = .072) in men and 1.70 (P < .01) and 3.24 (P < .05) in women for those with BMIs of 25-30 and ≥ 30, respectively, compared to those with BMI < 22, after adjusting for age, smoking status, and clinical history of diabetes mellitus. These findings demonstrate a dose-response relationship between BMI and the development of periodontal disease in a population of Japanese individuals.

Influence of beverage and food consumption on fluoride intake in Japanese children aged 3-5 years.

This study was conducted to estimate the relative contribution of particular foods and drinks to dietary fluoride intake in 94 preschool Japanese children in low-fluoride areas. The mean daily fluoride intake from all beverages (548 +/- 162 g) was 0.108 mg (SD = 0.082), accounting for 37% of the total dietary fluoride; tea beverages showed the highest value, 0.093 mg (SD = 0.081), 32%. That from staple food and side dishes was 0.183 mg (SD = 0.146), 63%, followed by cereals (12%), fish (8%) and bean products (5%). In conclusion, the contribution of beverages excluding tea to dietary fluoride intake is small in Japanese children.

Relationship between number of natural teeth in older Japanese people and health related functioning.

The objective was to assess the relationship between number of functional occluding natural pairs of teeth and health related functioning in older free living Japanese people using the SF-20. The participants were 107 elderly people aged 80 years. Health related functioning was measured with the SF-20. The numbers of functional occluding natural pairs of teeth (OPs) were calculated and scored as follows: 1, for each pair of anterior teeth and premolars in occlusion. Molar functional natural occluding pairs were scored 2 for each occluding pair. The number of functional occluding pairs was assessed separately as anterior natural occluding pairs (AOPs) and posterior occluding pairs (POPs). There were significant differences in the role functioning subscale of SF-20 between those who were edentulous and those with one to nine natural teeth and 10 or more natural teeth (P = 0.030). Those with one to six AOPs had significantly higher role functioning than the zero AOPs group (P = 0.042). Those with 1-12 POPs also had significantly higher role functioning scores than the zero natural POPs group (P = 0.007). However, there were no significant relationships between number of natural teeth, OPs or AOPs, and POPs on the one hand, and all other subscales of SF-20 on the other hand. The community-dwelling 80-year-old Japanese people in this study had overall good health related functioning. The number of functional occluding pairs of natural teeth, especially POPs, was related with the role functioning subscale of SF-20 but had no significant relationships to the other dimensions of SF-20.

Effects of smoking and drinking habits on the incidence of periodontal disease and tooth loss among Japanese males: a 4-yr longitudinal study.

OBJECTIVE: We investigated the risk of periodontal disease and tooth loss, associated with habits of smoking and alcohol consumption, in a longitudinal study. SUBJECTS AND METHODS: The subjects were 1332 Japanese males, 30-59 yr of age, who were free from periodontal disease at the baseline check-up, and who underwent a second check-up 4 yr later. Periodontal disease was diagnosed using the community periodontal index score, based on the clinical probing of pocket depth (> or = 4 mm). Smoking and alcohol consumption patterns were evaluated using a self-administered questionnaire. RESULTS: A dose-response relationship was observed between the amount of smoking and the incidence of periodontal disease in each age group. The overall odds ratios (95% confidence intervals), adjusted for age and alcohol, were 1.51 (0.95-2.22), 1.58 (1.13-2.22) and 2.81 (1.96-4.03), among smokers consuming 1-19, 20 or 21 or more cigarettes per day, respectively, with a significant linear trend (p < 0.0001). A similar association was found between smoking and tooth loss, except for the 50-59-yr-old age group. The adjusted odds ratios were 1.26 (0.60-2.64), 2.01 (1.21-2.32) and 2.06 (1.23-3.48), respectively. A significant linear trend between smoking and tooth loss was also observed (p = 0.01). Ex-smokers showed no significant difference compared with nonsmokers. We also found a significant linear trend between alcohol consumption and tooth loss among 30-39-yr-old subjects, while no relationship was observed between alcohol consumption and periodontal disease. CONCLUSION: Cigarette smoking was found to be an independent risk factor for periodontal disease and tooth loss. Alcohol consumption was a limited risk factor for tooth loss in the younger age group, but was unrelated to periodontal disease. To prevent periodontal disease and tooth loss, health practitioners need to encourage people to stop smoking or not to start.

Intra-oral fluoride retention 3 minutes after fluoride mouthrinsing in 4- to 5-year-old children: effects of fluoride concentration and rinsing time.

This study was undertaken to explore the site-specific retention rate and the possibility of shortening fluoride (F) mouthrinsing time of kindergarten children. Fluoride retention after 10-, 20- and 30-second mouthrinsing was determined in 43 kindergarten children aged 4-5 years. Tooth surfaces were sampled by a paper point method. Fluoride concentrations in the salivary film on tooth surfaces increased from primary molars to primary incisors in the maxilla and decreased from primary molars to primary incisors in the mandible. The fluoride solution reached the primary molars even after a 10-second rinse, but F concentrations were higher after 20 s than after 10 s and significantly higher after 30 s than after 10 s. No significant difference was observed between 20 and 30 s. The average total F retained in the mouth was 0.13 mg after 20 s and 0.17 mg after 30 s. It was concluded that 30-second mouthrinsing, which is used extensively in Japanese kindergartens, can be shortened to 20 s.

A method for mapping the distribution pattern of cariogenic streptococci within dental plaque in vivo.

This study was carried out to develop a method for mapping the distribution of cariogenic oral streptococci, Streptococcus mutans and Streptococcus sobrinus, from the outermost to the innermost plaque. Ten consenting subjects were asked to form plaque by abstaining from tooth brushing over 3 days within in situ plaque-generating devices, which were placed on the upper molars. The plaque formed in the devices was separated into 8-10 layered fractions (100 microm thick). Genomic DNA was extracted from each plaque fraction by a commercial DNA purification kit and used for the amplification of the 16S ribosomal RNA gene sequences by polymerase chain reaction (PCR) with universal primers. The products were then amplified by PCR with S. mutans- or S. sobrinus-specific nested primers. The final products were separated on agarose gels, stained and photographed to confirm the existence of S. mutans and S. sobrinus. The results showed that S. mutans was detected in the plaque obtained from all of the 10 subjects and S. sobrinus in the plaque of 7 subjects. However, the distribution patterns of fractions positive for S. mutans and S. sobrinus varied among the subjects, with a tendency for frequent detection of both species in the outer to middle layers of dental plaque. There were no plaque fractions in which only S. sobrinus was found. This method could be useful to map the distribution of cariogenic microorganisms and to estimate the bacterial ecology for oral biofilm.

Daily use of dentifrice with and without xylitol and fluoride: effect on glucose retention in humans in vivo.

The effect of daily use of three different dentifrices on glucose retention after glucose mouth rinsing was tested in this study regarding xylitol and fluoride. Six experimental groups used three different dentifrices produced by two different companies: xylitol- and fluoride-containing dentifrice (XF), non-xylitol- and fluoride-containing dentifrice (F), and non-xylitol- and non-fluoride-containing dentifrice (NonX-NonF). Subjects were divided at random and rinsed their mouths for 15s with 20ml of 0.5M glucose solution. Glucose and lactate retention were determined by collecting samples of saliva from the approximal areas of the maxillary and mandibular anterior teeth and using the enzyme membrane test. Samples were collected 0, 1 and 2 months after the start of regular dentifrice use. There were significant differences in glucose retention in relation to the dentifrice used, month of sampling, site of sampling, and time since start of rinsing. Their contribution ratios were 2.0, 4.4, 11.7 and 7.4%, respectively (P<0.01). There were significant differences observed between the XF and NonX-NonF groups, with the XF group presenting lower glucose retention than the NonX-NonF group. The XF group presented lower glucose retention than the F group. The F group showed lower glucose retention than the NonX-NonF group. There were significant differences in lactate retention in relation to the month and site of sampling, and their contribution ratios were 3.3 and 2.8%, respectively (P<0.01). There were, however, no significant differences in glucose and lactate retention in relation to the dentifrice manufacturer. It was concluded that the XF dentifrice was the most effective, and the F dentifrice was more effective in reducing glucose retention than the NonX-NonF dentifrice.

Fluoride intake in Japanese children aged 3-5 years by the duplicate-diet technique.

This study was conducted to determine the fluoride intakes in 94 preschool children aged 3, 4 and 5 (n = 30, 30, 34, respectively) residing in Yokkaichi, Mie Prefecture (< 0.16 ppm F water supply). The parents duplicated all the diets that their children ingested on 3 separate days during a 1-year period. The acid-diffusible fluoride in the diet was isolated by the acid-diffusion technique and measured with a fluoride electrode. The mean daily fluoride intakes from diet alone by children aged 3, 4 and 5 were 0.30 mg (n = 29, SD 0.19), 0.28 mg (n = 30, SD 0.19) and 0.30 mg (n = 34, SD 0.19), respectively. The total estimated mean values from diet and dentifrice were 0.35 mg (n = 29, SD 0.22, range 0.13-1.00), 0.33 mg (n = 30, SD 0.19, range 0.13-0.86) and 0.39 mg (n = 34, SD 0.18, range 0.18-1.01), respectively. It was concluded that the mean (+/-SD) total fluoride from diet and dentifrice in 3- to 5-year-old Japanese children was 0.35 +/- 0.19 mg/day (0.021 +/- 0.012 mg/kg body weight).

The influence of salivary variables on fluoride retention in dental plaque exposed to a mineral-enriching solution.

This study was carried out to examine interindividual differences in salivary variables related to plaque accumulation and to estimate their influence on the fluoride retention in plaque in vivo by a mineral-enriching solution. Two saliva samples were taken from 10 subjects, once after brushing and once after 24 h without brushing. Calcium, phosphate and monofluorophosphatase (MFPase) activity in the saliva samples were determined. The salivary flow rate and the debris index were also recorded. After plaque had formed over 3 days within in situ plaque-generating devices, subjects were instructed to rinse with a mineral-enriching mouthrinse three times a day on 4 consecutive days. Plaque exposed to distilled water plus flavoring agents served as a control. Fluoride-free dentifrice was used during the experimental period. Twenty-four hours after the last rinsing, the samples were removed from the mouth, and fluoride and mineral distributions in plaque analyzed using a method previously reported by the authors. Salivary flow, MFPase activity and calcium concentration in saliva were significantly higher after 24 h of plaque accumulation. Rinsing with the mineral-enriching solution produced retention of fluoride and phosphate in the outer and middle layers of plaque. Salivary calcium concentration had a direct effect on fluoride uptake in plaque, but no obvious relationship was found between other salivary variables and the plaque fluoride retention. The salivary calcium effect may be due to enhanced bacterial cell wall binding of fluoride via calcium bridging.

[A variant form of septo-optic-pituitary dysplasia (SOPD) complicated with acute optic neuritis].

We herein report a case of a variant form of septo-optic-pituitary dysplasia (SOPD). A 40-year-old man was admitted due to sudden occurrence of left blurred vision and lasting polyuria. He showed short statue of height of 144 cm and the neurological examination revealed hypesthesia of the left trigeminal nerve and temporal pallor in the left fundus oculi. Brain MR imaging demonstrated agenesis of the septum pellucidum and hypoplasia of the corpus callosum with subcortical spotty lesions, but optic nerve hypoplasia was not detected. The left eye showed a prolonged P100 latency of pattern reversal VEPs. He was diagnosed as having hypopituitarism since growth hormone-releasing factor did not stimulate growth hormone secretion and restriction of water-intake did not induce secretion of antidiuretic hormone. Thus we regarded this case as a variant form of SOPD. The mutation of HESX 1 gene, however, was not detected in the case. P100 of the left eye showed a reduction in latency four months after discharge. This case was considered to be a variant form of SOPD complicated by acute optic neuritis.

Use of fluoridated dentifrice and glucose retention at the approximal areas of anterior teeth.

The present study was undertaken to learn to what extent the use of dentifrice with fluoride affected glucose retention after glucose rinsing. Fifty-eight subjects consisting of forty male adults and eighteen female adults whose average age was 21.9 years were divided at random into two groups; one group used fluoridated dentifrice and the other group used nonfluoridated dentifrice. Subjects rinsed their mouths for fifteen seconds with 20 mL of 0.5 M glucose solution. Samples of saliva were taken from the approximal areas between the right and left central incisors of the maxilla and mandible by inserting the tip portion of a paper point three-minutes after the glucose rinsing, sample of saliva were taken from the neighboring approximal areas of the left central and left lateral incisors. Glucose content of the paper points was determined using the enzyme membrane method. Determinations were made before and at the end of the first, third, and fifth month over a five-month period. Fluoride concentrations in the resting saliva were also determined in different months during this period. At three-minutes and six-minutes, glucose retention in the group using fluoridated dentifrice was found to decrease slightly throughout the experiment; while glucose retention in the group on nonfluoridated dentifrice leveled off or increased in the fifth month. Fluoride concentration in the resting saliva increased during the experiment in the group using fluoridated dentifrice; while fluoride concentration in the group using nonfluoridated dentifrice did not change. It was concluded that the regular use of fluoridated dentifrice made glucose retention slightly lower and fluoride level in whole saliva higher.

Fluoride concentrations at and near the neonatal line in human deciduous tooth enamel obtained from a naturally fluoridated and a non-fluoridated area.

This study sought to obtain a precise profile of fluoride concentrations at and near the neonatal line in deciduous incisors and canines from the naturally fluoridated area (1.0--1.3 parts/10(6) F in drinking water) of West Hartlepool and the non-fluoridated area (less than 0.1 parts/10(6) F in drinking water) of Leeds in England. An abrasive microsampling method was used to determine the distribution of fluoride and phosphorus concentrations. The profile of fluoride concentrations in 100-microm layers before and after the neonatal line, that is, in the prenatal and postnatal enamel, were significantly higher in teeth from the fluoridated than non-fluoridated areas. It was concluded that the fact that the fluoride concentrations were about the same prenatally and postnatally in deciduous enamel obtained from the fluoridated and non-fluoridated areas indicates that fluoride enters the prenatal deciduous enamel and that it is transferred through the placenta.

Oral glucose retention, saliva viscosity and flow rate in 5-year-old children.

There are significant differences of glucose retention in site-specificity and individuals. Sixty-two 5-year-old nursery schoolchildren participated in this study on the relation between the viscosity of saliva and flow rate and glucose retention. Each child was instructed to rinse his/her mouth with a glucose solution (0.5 M, 5 ml) and then to spit out. Three minutes after rinsing, glucose retention was determined. Resting saliva was collected by a natural outflow method, then the flow rate was determined. A rotational viscometer was used to determine the viscosity. Glucose retention and flow rate were correlated at the left maxillary primary molars, and glucose retention and viscosity were correlated at the maxillary central primary incisors. It was concluded that glucose retention after glucose mouth rinsing was site-specific, and that glucose retention and the index of decayed, missing and filled primary teeth (dmft) were slightly correlated with the salivary viscosity and flow rate.

[An oral health scoring system for promoting 8020 achievement in residents].

The present study was undertaken to develop a self-scoring system which can be used by a resident to check lifestyle. The oral health scoring system which we used in Tobishima village, Aichi-ken, was named SAWAYAKA score. A total of 777 subjects were examined. The subjects responded to a questionnaire regarding their past individual lifestyles and dietary habits. Oral health conditions were also examined by dentists. The odds ratio and 95% confidence interval were calculated both from retained tooth numbers and the questionnaire. Questions with significant odds ratio were selected and the partial regression coefficients of quantification II method by Hayashi were calculated. The results are as follows; 1) Eleven questions showed a significant odds ratio between retained tooth numbers and past lifestyle and dietary habits. The questions involved the frequency of snack intake, tooth brushing frequency, having own tooth brush, smoking, drinking, having a hobby, having a family dentist, consulting a dentist before a problem got serious, gum bleeding, swollen gums and toothache caused by sensitivity to cold water. 2) The eleven items were analysed by using Hayashi's quantification II method. 3) The results showed that unswollen gums affected the retention of teeth by the range of 1.240. Toothache caused by sensitivity to cold water affected the retention of teeth by the range of 0.765. Having a hobby affected the retention of teeth by the range of 0.691. 4) The "SAWAYAKA" score was used to select important items, excluding drinking. 5) When results were analysed with the SAWAYAKA score, an average of 9.6 was obtained. It was concluded that the scoring list could be used for checking resident's lifestyles, and for promoting the preservation of more than 20 teeth at the age of 80.

Fluoride profiles in dental plaque in vivo formed on fluoride pre-treated human enamel.

Using a novel device capable of generating plaque in vivo on a natural enamel substrate, it has been possible to determine fluoride profiles from the saliva-plaque interface towards the enamel surface. Fluoride profiles in dental plaques tended to fall from the saliva-plaque interface towards the enamel. The device also offered the possibility of examining fluoride distributions after pre-treatment of the enamel with fluoride in vitro. Fluoride profiles were determined in plaque generated in vivo on enamel surfaces, which had been previously treated with a 900-ppm fluoride solution. The results showed the previously reported fall from the plaque surface, but in addition, a further rise towards the enamel surface was seen. The data imply that enamel loaded with fluoride can release some of this fluoride back into the plaque and may act as a fluoride reservoir.

Fluoride and magnesium concentrations in human dental calculus obtained from Japanese and Chinese patients.

Calculus deposited on a total of 68 permanent teeth from patients 30-60 years old from Nagoya in Japan and Beijing in China was investigated. An abrasive microsampling method was used to examine the fluoride (F) and magnesium (Mg) distribution, using a fluoride ion-specific electrode and atomic absorption spectrophotometry, respectively. F concentrations decreased from the surface towards the interior of the calculus. Mg concentrations, however, gradually rose towards the innermost surface adjacent to the tooth. In all parts of the depth profiles, the average concentrations of both magnesium and fluoride were higher in the Japanese than in the Chinese calculus. Towards the inner surface of the calculus, F and Mg concentrations were also much higher in the Japanese than in the Chinese group. A greater intake of sea foods and greater use of fluoride dentifrices are possible reasons for the higher F and Mg concentrations in the Japanese individuals.

[Work load analysis for oral care in special nursing homes].

The work load analysis for oral care in special nursing homes. Dental hygienists undertook oral care of 100 person who were confined to special nursing homes in Aichi prefecture, Japan. The time required, the physical load, the psychological burden were analysed. The results were summarized as follows; 1) Oral care by dental hygienist was incorporated as one of the 59 care tasks given in special nursing. 2) The working time for required oral care was 25.7 minutes per resident on an average. 3) In general, speaking to the elderly, recording on an assessment card, and observing conditions were undertaken most frequently. In oral care, tooth cleaning, gargling, cleaning of dentures, wiping of the mouth and advising those caring for the elderly, was performed most frequently. 4) In general, time taken for advising those caring for the elderly, report to the home dentistry, advising the elderly, recording, and evaluation was most common. In oral care by a dental hygienist, tooth cleaning, cleaning of the dentures, cleaning the mouth, gargling, prevention of dryness of the mouth were performed most frequently. 5) In physical activity, raising the person, moving him from the wheelchair to the bed and helping him to lie down were most frequent. In oral care by a dental hygienist, wiping the mouth, inserting dentures, tooth cleaning, cleaning the mouth and removing dentures were most common. 6) The psychological burden when lifting the person, moving him from the bed to the wheelchair and helping him to lie down was the greatest. In burden involving oral care by a dental hygienist, tooth cleaning, removing dentures, inserting dentures and cleaning the mouth were the greatest.

Magnesium and fluoride distribution in human cementum with age.

Sixty-two human teeth, obtained from subjects aged 11 to 80 years, were used to determine the magnesium and fluoride concentration and distribution with age in human cementum. Transverse sections were prepared from the root region of teeth. Samples, each 30 microm thick, were abraded in sequence from the cementum surface and the cemento-dentine junction by an abrasive micro-sampling technique. Magnesium concentrations were lower in the cementum surface, and increased towards the cemento-dentine junction (CDJ), while fluoride concentrations were higher in cementum surfaces and tended to decrease towards CDJ. Fluoride distribution patterns were similar to that reported earlier while average fluoride concentration increased with age, however, either no change or decreasing tendencies were observed with magnesium.