Periodontal disease involves in inflammation of tissues which support the teeth, and in primarily caused by the accumulating bacterial plaque on the teeth. The extraction of teeth is the end stage. Current statistics show that about 60% of young adults and 80% of adults in the U.S. have periodontal disease, i. e., this disease is not limited just to the older generations.
The initially available Coenzyme Q₇ (CoQ₇) was clinically found to improve therapeutically severe and destructive periodontal disease. CoQ₇ had been found to show 80-100% of the activity of Coenzyme Q₁₀ (CoQ₁₀) for NADH-oxidase.
The partially synthetic hexahydro-CoQ₄ (H₆CoQ₄) became abundantly available for clinical research, although it showed only 10-25% of the activity of CoQ₁₀ for NADH-oxidase. Over ca. five years, H₆CoQ₄ was clinically tested, including a double-blind trial, for therapy of periodontal disease, and was found to cause such extraordinary healing that H₆CoQ₄ was considered as conjunctive therapy for ordinary dental practice.
It had been determined that there was a statistically significant deficiency of CoQ₁₀-enzyme activity in gingival biopsies from patients with periodontal disease in comparison to control. In due time, CoQ₁₀ became available for clinical studies on therapy of periodontal disease. After an open trial of treating periodontal disease with CoQ₁₀, which was interpreted to the effect that healing was--“dramatically accelerated”--and was--“very impressive”, a successful double-blind trial was conducted with capsules of CoQ₁₀ and a matching placebo.
Subsequent trials were concluded with the observation that--“CoQ₁₀ could well become an essential modality of prevention and treatment of periodontal disease”.
These open and double-blind trials were largely based upon criteria of periodontal score, tooth mobility, gingival index and pocket depth. Recently, the bleeding index was another criterion of therapy, and the result was positive.
Currently, the reduction of subgingival microorganisms has been recorded, and concomitantly, it was recorded that CoQ₁₀ increased the levels of the T4/T8 ratio and that of IgG.
The repeatedly demonstrated successful therapy with CoQ₁₀ of periodontal disease is evident from several criteria showing reduced disease, from criteria of an improved immune system, and restored periods of natural prevention of disease.
CoQ₁₀ is, therefore, recommended for both prophylactic and therapeutic treatment of periodontal disease.

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An epidemiological study of 2, 012 children by oral examination and questionnaire was undertaken to study the dental caries prevalence in one kindergarten and two elementary schools in an urban area and in one kindergarten and two elementary schools in a country area in 1989. The data showed that the dental health status was poor and that living habits and public medical service were unsatisfactory when compared with the results of other dental surveys in Taiwan R.O.C..
In the urban area caries prevalence in deciduous teeth in the kindergarten was 74.2%, and in permanent teeth in the two elementary schools it was 56.3% and 57.1%. In the country area caries prevalence in deciduous teeth in the kindergarten was 95.0% and in permanent teeth in the two elementary schools it was 68.0% and 56.4%, respectively. The dft index was 6.30 in the urban area and 9.00 in the country area, and the DMFT index was 1.87 and 1.58 in the urban area, and 2.02, 1.52 in the country area. The FT rate showed a low restorative treatment rate in both deciduous and permanent teeth. The ft rate was from 1.4% to 6.3% in kindergarteners and FT rate in elementary school children was from 10.5% to 35.6%.
The results of the questionnaire regarding living habits, living environment and medical service were as follows:
1. Subjects who received topicl fluoride application or regular dental examination were few and there was a high percentage of experience of toothache and dental treatment. But because of the deficient public health system, the treatment of dental caries was mostly temporary treatment only, and therefore experience of both toothache and dental treatment were frequent.
2. The answers to the questionnaire showed that the parents know and acknowledge the use of fluoride.
Our dental survey showed that dental caries is increasing in Taiwan and is near the level of Japan. There is no obvious difference in the public dental health situation or the living environment between the regions surveyed, and no definite direction could be observed between caries prevalence and living habits or living environment. The knowledge and acknowledgement of parents concerning fluoride will help to establish a community dental policy and contribute to the developement of school dental health.

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The purpose of this research was to clarify the difference between the children who can or cannot chew and swallow properly, by observation of eating behavior and by measurement of masticatory function.
The examinees were 107 children in a kindergarten in Tokyo. For assessment of their eating behavior, the attitudes and behavior of each child during lunch were observed, and features of the behavior were recorded. The children were classified into two groups, one with and the other without abnormal chewing and swallowing habits, by the teachers of the kindergarten. Regarding masticatory function, electromyograms of masseter and temporal muscles were recorded for five sample foods. Chewing gum masticating test, biting force, and occlusal contact area were evaluated.
1. 37 children were included in the group with abnormal chewing and swallowing habits by the teachers, and the others (70) were put the group with no problems. Eating behaviors observed in these examinees were analyzed in the two groups by Hayashi's guantification method II, and the highest partial correlation (0.583) was observed for slow eating.
Compared with the group with no problems, the group with abnormal habits showed more number of masticatory strokes and longer time in chewing sample food, and thus, they seemed to be confirmed as slow eaters functionally. However, no statistically significant differences between the two groups were observed in masticatory rhythm, which is one of the important factors in slow eating.
2. Eating behavior was analyzed by Hayashi's quantification method III, and as result, the children were classified into three groups, A (44 children), B (38), and C (25).
Children in group A seemed to have no or minimal problems in their eating behavior. Assessment of masticatory function showed that they had the lowest number of strokes and shortest time among the three groups in mastication of sample foods. Electromyograms of this group showed smaller variations in rhythm and greater muscle activity than the other two groups. This group showed maximal value in biting force and widest area of occlusal contact. These findings suggest that children who had no problems in their eating behavior had well-matured masticatory function.
In Children in group B, masticatory activity was frequently interrupted with no concentration of the attention on food, and the foods were just kept in their mouth, though they had an active attitude toward the meal. In assessment of masticatory function, children in group B exhibited lower muscle action potentials in electromyograms and weaker biting force than the other two groups, which seemed to suggest that they had problems in development of masticatory muscles.
Eating behavior of children in group C was characterized by the lack of interest in the meal. They were all slow eaters. Analysis of masticatory function revealed that this group had the highest number of strokes and the longest time among the three groups for chewing sample food. Electromyograms showed highest coefficients of variation in the duration, the cycle, and the mean muscle action potentials among the three groups. This group exhibited lower biting force than group A, but no statistically significant differences were observed. These findings show that children in group C had greater intra-group variation in rhythm and muscle activity during mastication, which seemed to suggest that lacked interest in the meal, which was caused by everyday eating habits rather than by under development of masticatory muscles.

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A knowledge of fluoride uptake and distribution in tooth deposits and underlying tooth surfaces could provide useful information about availability and action of fluoride in the oral environment and oral fluids. Fluoride concentration and distribution were therefore measured in supra- and subgingival calculus and at the underlying enamel or cementum surfaces using a mechanical sampling technique and a fluoride electrode (Weatherell et al., 1985).
In this study, twenty extracted teeth with supragingival calculus and twenty teeth with subgingival calculus removed from subjects aged 44 to 67 years old were used. Phosphorus distributions were also determined using a x-ray microanalyser.
The results were as follows;
1) Fluoride concenerations were highest at the surface of dental calculus. There was a lower level plateau for the interior, which rose again as the tooth surface was approached.
2) Supragingival calculus tended to show a smoother profile compared with that of subgingival calculus.

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[in Japanese]

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Few studies have been reported on the glucose clearance (retention) at different sites on the tooth surfaces. The present study was undertaken to examine the glucose retention (clearance) in the central incisor and first molar of human mouths in 23 volunteer subjects (mean age; 23.3 yrs). Each subject throughly rinsed the mouth for 15s with 20ml of a 0.5M glucose solution and expectorated gently. Small paper-points were fixed to the mesial, distal, buccal, lingual and of the occlusal tooth surfaces. The amounts of gluccse at 3 min were measured with a suger analyzer.
The results were as follows;
1) The glucose concentration was highest at the labial surface and lowest at the lingual surface in the central incisor in both maxilla and mandibulla.
2) The glucose concentration was highest at the mesial surface and lowest at the occlusal surface in the first molar in the maxilla, it was highest at the buccal surface and lowest at the lingual surface in the first molar in the mandibulla.
It was concluded that there was difference of glucose clearance on tooth surfaces.

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Alkaline phosphatase (Al-P) activity and 3′, 5′ cyclic AMP (cAMP) levels in plasma and bone in rats experimentally poisoned with fluoride (F) were determined and compared with the results of pair feeding.
1) As F doses increased, the uneaten food in F intake groups increased. This was about 30% in 4mg F groups and about 50% in 6mg F groups. Body weight was lower in F intake groups than in control groups. The change in body weight in pair feeding control groups showed the same pattern as in F intake groups.
2) Al-P activity in plasma was significantly greater in 4mg F groups and 6mg F groups than in pair feeding control groups (p<0.05 and p<0.01, respectively).
3) Al-P activity in bone appeared to increase in F intake groups compared to control groups. Al-P activity in bone was lower in pair feeding groups used as controls to 4mg F groups or 6 mg F groups than in the respective F intake groups.
4) Cyclic AMP level in plasma was higher in F intake groups than in control groups. There was significant difference between control groups and both 4mg F and 6mg F groups (p<0.01). Plasma cAMP level in pair feeding control groups was about same level as control groups.
5) Cyclic AMP level in bone tended to be higher in F intake groups than in control groups. There was a significant difference between control groups and 4mg F groups (p<0.01). Bone cAMP level in pair feeding groups used as controls to 4mg F or 6mg F groups was similar to the level in control groups.
6) F concentration in both plasma and bone increased in proportion to the dose of F. There was a significant positive correlation between Al-P activity and F concentration.

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Little information is available about the distribution of magnesium in the human bone, although several studies have been reported on the whole sample of bones. Therefore the present study on magnesium distribution in human ribs was carried out. Sixty human ribs obtained from subjects aged 10 to 80 years were cut transversely. Two transverse sections from periosteal to endosteal surface were ground to a thickness of about 1000μm. One section was used for magnesium determination by atomic absorption spectrophotometry and the other for analysis with XMA. Specimens were taken across the rib cortex. Layers 30μm thick were abraded serially from the periosteal to endosteal surfaces by abrasive microsampling as previously described (Weatherell et al. Caries Res. 19; 97-102, 1985). Analysis showed that magnesium concentrations were higher both in periosteal and endosteal surfaces. Neither the profile nor the overall concentration of magnesium, however, changed with age.

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Changes in lased human dental enamel after immersion in human resting whole saliva were investigated by the determination of Vickers hardness number (VHN) and amount of calcium released into acid solution, and also by polarized light microscopy and scanning electron microscopy (SEM). Lased enamel had a lower VHN than unlased enamel, but it rehardened significantly after immersion in saliva for 5 days. The VHN of lased enamel became larger as the period of immersion in saliva increased.
A high positive birefringence of lased enamel was reversed during the immersion in saliva. After immersion for 10 days, the lased area showed a low negative birefringence which was similar to that of the unlased enamel. The rehardening and the change in birefringence of lased enamel were attributed to deposition of salivary ions in microspaces created in dental enamel by laser irradiation.
The amount of calcium dissolved from enamel which was lased and subsequently immersed in saliva for 10 or 20 days was higher than that from enamel which was lased only. However, the lased enamel still retained significantly higher acid resistance than unlased enamel even after immersion in saliva for 20 days. No remarkable change of the surface of lased enamel was observed by SEM after immersion in saliva.
Those results suggested that lased enamel gets a structural stability by rehardening and it retains high resistance to an acid attack in the oral cavity.

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20-year-old adults had previously participated in a daily 0.05% NaF mouth rinsing program from age 4 to 11 and in a weekly 0.2% NaF mouth rinsing program from age 12 to 14. The caries prevalence of this fluoride group was compared with that of similarly aged adults who had no experience of any fluoride program. In the fluoride group, there was significantly lower caries prevalence than in the control group. There was a 45%-58% difference in the mean DMFT, and a 56%-71% difference in the mean DMFS. All of the mean DMFS by tooth types and tooth surfaces in the fluoride group were lower than those of the control group. The greatest reduction, 79%-97%, occurred in anterior teeth, and a reduction in the smooth surfaces (61%-92%) was higher than that in pits and fissures (44%-60%). In the fluoride group, there were far fewer missing teeth, and the mean number of highly progressed caries teeth was less than one-half in the control group.
These results in 20-year-old adults indicated that participation in the fluoride mouth rinsing program for 11 years from age 4 to 14 conferred post-treatment benefits.

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This study compared the effectiveness of two rechargeable powered toothbrushes, the counter-rotational action powered toothbrush (INTERPLAK®) and the reciprocating powered toothbrush (Power brush®), in removing supragingival plaque and resolving gingivitis. Sixty adults with gingivitis and slight periodontitis were randomly assigned to one of the two powered toothbrush groups. Plaque scores before and after brushing were assessed and soft tissue abrasiveness and gingival inflammation were checked at baseline, 2, 4, and 8 weeks by blind examiners. There was no statistical significance of mean values between the two groups at the baseline. The results suggested that the counter-rotational action powered toothbrush was more effective than the reciprocating powered toothbrush in removing supragingival plaque, and that there was no significant superiority of either type of powered toothbrushes in resolving gingivitis. However, a questionnaire given after the final examination indicated that inconvenience was experienced slightly more often by the counter-rotational action powered toothbrush group.

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Epidemiological analyses using the Ramfjord Plaque Index (PI) were performed on 881 mental retardates possessing one or more subject teeth at 15-48 years of age. They were among a group of 1107 subjects who were admitted to the Niigata Prefectural Institute of Total Training for the Mentally Retarded, Colony Niigata Shiroiwa-no-Sato, during the years 1971-1988. The personal rates classified by maximum PI score and average number of sextants per person according to PI grades were compared, with regard to the attributes supposed to be an influential factor, and 3 periods of admission, the years 1971-1975, 1976-1981 and 1982-1988. There was a difference in oral hygiene status between males and females in the first half of the 1970's, but toward the 1980's the oral hygiene status of male newcomers had improved, and this difference disappeared. It appeared that there was no difference between profoundly to severely retarded and moderately retarded or between histories of non-institutionalization or institutionalization before admission. No difference among adimission periods was recognized in oral hygiene status of females.

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Oral fluoride retention was studied following the topical application of acidulated phosphate fluoride (APF) gel with a toothbrush. Forty-four children (aged 1.5years) were treated by 3 hygienists. The amount of APF gel prepared for each child was 0.81±0.09g (Mean±SD). The amount of retained fluoride was 2.09±0.07mg. The amount of retained fluoride per body weight was 0.19±0.06mg ranging from 0.07 to 0.31mg. This fluoride application technique using a toothbrush was easier than using a tray, and was accepted well even by younger children.
The results show that children do not ingest toxic doses of fluoride when this application technique is employed.

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Early remineralization in root surfaces with cementum was evaluated by conbining a single-section technique with videodensitometry.
A total of 10 root sections 125-μm thick were cut individually from 10 samples of freshly extracted sound human premolars and coated with nail varnish leaving a window on the cementum surfaces. After demineralization by immersion in 0.01M lactate buffer (6mM Ca, 3.6mMP, 1% CMC, pH 5.1) at 37°C for 48 hours, all specimens were immersed in remineralizing solution (3mM Ca, 1.8mMP, 150mM NaCl, 2ppm F, 1% CMC, pH 7.0) at 37°C for 7 days. The changes in mineral volume were assessed quantitatively by videodensitometry for the microradiographs prepared before and after remineralization.
Results were as follows:
(1) Approximately half the mineral volume accumulated during the 7-day remineralization was acquired whthin the first 2days. This fact indicates that the degree of remineralization in root surfaces progresses rather rapidly.
(2) From the digitized microradiographic images, initial remineralizing sited appeared to be located in the subsurface layer of cementum.
(3) We suggest that the degree of in vitro remineralization should be evaluated within a short period when a seingle-section technique is used.

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The special service of public health sponsored by the Brazilian government began the fluoridation of water in Baixo Guandu, a small town in the state of Espirito Santo in 1953. In a survey done by the FDI in 1981, 7, 500, 000 inhabitants were drinking fluoridated water in 122 communities. Although so many people are drinking fluoridated water in Brazil, the present condition of fluoridation in Brazil is not known in Japan. For this reason we conducted an investigation of the water supply in São Paulo, Piracicaba, and other cities.
1. The water in São Paulo has been fluoridated to 0.7ppm with 25% H₂SiF₆ since 1985. Recovery rate of fluoride in tap water was 82.7%.
2. The water in Piracicaba has been fluoridated to 0.7ppm with Na₂SiF₆ since 1971. Recovery rate of fluoride in tap water was 99.6%.
3. We measured the anion levels (F^-, Cl^-, NO₃^-, SO₄^2-) in the drinking water of several large cities. We found artificial fluoride in the drinking water of Belem, Iguacu, and Ferraz de Vasconcelous.
4. We compared the public water allowance for fluoride concentration in Japan, Brazil and WHO. The Japanese allowance is 1/2 of that of Brazil and WHO.

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