Increases in fluoride, calcium, and phosphate in dental plaque resulting from the use of a mineralizing mouthrinse containing urea and monofluorophosphate.

A mouthrinse used ten times over a four-day period increased the concentration of acid-extractable fluoride in immature plaque by 320%, calcium by 190%, and phosphate by 97%. Corresponding increases in mature plaque were smaller, yet significant. Diffusion of the ions from plaque was restricted, and hence a prolonged caries-inhibitory effect can be expected.

Plaque minerals and caries experience: associations and interrelationships.

Inverse associations were demonstrated between DMFT and total calcium, phosphorus, magnesium, strontium, potassium, and fluoride concentrations in individual plaques. Lithium, strontium, fluoride, and zinc contents were inversely related to plaque mass. Consistent interdependence patterns between elements indicate the operation of a mineral level regulating mechanism, effective under diverse environmental conditions.

Immediate and delayed effects of an enzyme-dependent mineralizing mouthrinse on dental plaque.

Twenty-two children aged 13 to 14 years rinsed for 3 X 1 min periods with a supersaturated calcium phosphate solution containing urea and monofluorophosphate. Plaque sampled one min after the last rinse showed a marked increase in water-extractable F and a smaller increase in Ca but no increase in water-extractable P. Water-insoluble forms of all three ions were elevated, however. The mean plaque pH was 8.28. Plaque sampled 24 hr after the last rinse showed significant increases in water-insoluble F and Ca only, and no increase in pH. The prompt pH rise and disappearance of water-soluble P suggest that, on exposure to the mineralizing solution, urea and monofluorophosphate are rapidly hydrolyzed by plaque enzymes to provide catabolites which cause the immediate precipitation of fluoridated calcium phosphate.

Calcium content of river water, trace element concentrations in toenails, and blood pressure in village populations in New Guinea.

Several studies carried out on industrialized population groups have revealed the presence of an inverse relationship between hardness of drinking water and certain cardiovascular parameters, e.g., death rates, blood pressure, blood cholesterol, etc. In the present paper an attempt was made to see whether such an association also exists in primitive population groups who drink untreated water collected directly from rivers. Blood pressure was measured in persons living in villages along the banks of the Wogupmeri river in New Guinea. The water was analyzed for calcium content. Trace element concentrations were also determined in toenails from the same subjects to see whether a correlation existed. Calcium content of river water decreases as the river flows downstream, while blood pressure of the villagers living along this river increases. The trace element analysis of toenails revealed strong correlations between aluminium and vanadium. The concentrations of these two elements decrease with age. This association is present in both sexes, in adults and in children. A similarly strong correlation also exists between these two elements in staple food. The results of the present investigation tend to confirm the findings of other studies indicating an apparently beneficial effect of relatively hard water on cardiovascular parameters. The concentration of aluminium and vanadium in toenails show interesting trends, the biological meaning of which, if any, is still unknown.

Associations between the total fluoride content of dental plaque and individual caries experience in Australian children.

Individual caries experience (DMFT) and the total fluoride content of dental plaque were determined for 72 schoolchildren, aged 9.7-13.0 years, lifelong residents in one of three New South Wales towns, where the fluoride levels of the reticulated water supplies were: Katoomba, less than 0.1 parts/10(6); Sydney, 1.0 parts/10(6) for 4 years; and Yass, 1.0 parts/10(6) for 16 years, prior to sampling. The mean fluoride content of plaque in Sydney (22.6, s.d. = +/- 16.8 parts/10(6)) and Yass (25.6, s.d. = +/- 16.4 parts/10(6)) differed significantly (t = 2.27, P less than 0.05 and t = 3.30, P less than 0.02, respectively) from that in Katoomba (13.5, s.d. = +/- 8.3 parts/10(6)). Significant inverse associations were demonstrated between total plaque fluoride and individual caries experience (DMFT) in Sydney (r = -0.45, P less than 0.025) and overall (r = -0.28, P less than 0.010). Inverse trends were established between plaque quantity (dry weight of plaque collected) and fluoride levels. No associations could be demonstrated between fluoride treatment (dentifrice, tablets or topical application) and plaque fluoride, DMFT or plaque quantity.

Betal chewing and caries experience in New Guinea.

The prevalence of dental caries and variables relating to the betel-chewing habit were examined in a sample of 301 rural New Guineans aged 12--24 years. Consistent inverse associations were demonstrated between caries experience and the intensity of betel chewing for individuals and aggregates of subjects. The results indicate that betel chewing confers a degree of protection against caries.

Caries experience and sex related tea consumption amongst 13-14-year-old children in Palmyra, Syrian Arab Republic.

Associations were examined between caries experience and the volume of tea consumed/day by schoolchildren in Palmyra, Syria. Girls had significantly high DMFT scores and consumed less tea than boys.

Oral conditions in Australian children of Aboriginal and Caucasian descent.

Oral health parameters were examined for 211 schoolchildren (128 Aborigines and 83 Caucasians) representative of the 6--8 and 10--11 year age groups in the Brewarrina and Walgett areas of western New South Wales (fluoride in water less than or equal to 0.02-0.26 parts/10(6)). Despite similar dietary carbohydrate challenge and tooth eruption patterns, Aboriginal children, most of whom were members of a transitional community within a low socioeconomic stratum, had higher prevalence of caries (DIMFT) and severity rating of carious lesions (SR), poorer oral hygiene (OHI) and more gingivitis (PI) than Caucasian children, in both age groups. Tooth defects were more frequent (2.5 times) and severe in Aborigines than in Caucasians. Outstanding treatment needs were very high in both ethnic groups, but more so in Aborigines.

Oral health of adolescent and adult Australian aborigines.

A pilot survey of oral health included 83 adolescent and adult Aborigines (41 M, 42 F, range 16--70 years, mean age 37.3 years), resident in fringe settlements around the far western New South Wales towns of Brewarrina and Walgett (fluoride in water less than or equal to 0.02--0.26 parts/10(6)). Dental caries prevalence (mean DIMFT per person) increased from 17.1 at 20 years to 10.7 at 35 years and declined to 14.6 by the age of 50 years and over. Oral hygiene (OHI) was poor overall and deteriorated with age. Periodontal status (PI) was significantly correlated with the presence of debris (DI) and calculus (CI). The mean PI increased from 1.7 at 20 years to 4.8 at 43 years and over. Tooth mortality reached 75% by the age of 43 years. Prosthetic needs were correspondingly high, but 95% of denture requirements were unmet. No evidence of effective or sustained oral health care was seen; 38% of subjects needed emergency treatment.

Oral health of Australian children using surface and artesian water supplies.

Oral health parameters were compared for 6--8 and 10--11-year-old children living in neighbouring. N. S. W. towns, where the community water supplies consisted of artesian and river were respectively. The demographic characteristics, living pattern and dietary carbohydrate challenge were similar in the two areas and effective oral hygiene practices were uniformly lacking. Children in the artesian water area had 40% lower caries prevalence (DIMFT), 50% less severe carious lesions (SR) and significantly better oral hygiene (OHI) and gingival condition (PI) and correspondingly lesser treatment needs than those supplied by river water. The findings were examined in relation to the concentrations of 10 elements in roof catchment, river and artesian water. Apart from a contribution by fluoride to better oral health, the results implicate lithium as a possible beneficial element.

Physiological indicators of fluoride exposure and utilization: an epidemiological study.

Individual samples of urine, fingernails, head-hair, saliva, plaque and enamel were collected from three groups of Hungarian children, aged 14 years, who were exposed to contrasting water fluoride levels (less than or equal to 0.11 ppm; 0.5-1.1 ppm; 1.6-3.1 ppm). The mean fluoride concentration of the samples increased consistently and significantly, but mostly non-proportionately, with increasing water fluoride level. With the exception of plaque, the materials examined are considered suitable indicators of exposure to or systemic utilization of fluoride for population groups. Caries experience decreased with increasing fluoride exposure. Dental fluorosis constituted no clinical or aesthetic problem.

Cervical chordoma: case report.

Chordomas of the cervical spine are rare. A case of a cervical chordoma is described. The initial radiological misinterpretation was due to the unavailability of CT myelography or MRI. Treatment of this disease is difficult, with multiple operations often required. Tumour bulk at diagnosis, completeness of surgical excision, availability of radiotherapy and biological behaviour of the chordoma are the main determinants of survival. Our case is interesting in terms of long survival which is 11 years to date. On reviewing the recent literature we have not found separate survival statistics for cervical chordoma, however, we have found 4 other cases of cervical chordoma with survival greater than 10 years.

The fluoride content of human tooth enamel in relation to environmental exposure to fluoride.

Double-layer superimposed biopsies were used for sampling sound labial enamel of upper permanent central incisor teeth of 189 children (mean age 8.4 years, SD = 0.36), comprising five groups, representing life-long exposure to contrasting concentrations of F in the water (range less than or equal to 0.12 ppm to 2.8 ppm) and to supplements of 200 or 350 mg F/kg domestic salt. The mean F concentrations of enamel ranged through the groups from 924 ppm to 2401 ppm in the surface layer (average central depth = 0.49 micron) and from 450 ppm to 1428 ppm in the subsurface layer (average central depth = 2.62 microns). The differences between the mean F concentrations of the groups were significant in each instance and the values consistently reflected the extent of F exposure. It was concluded that the F content of enamel is a reliable indicator of environmental exposure to F for populations, but not for every individual.

Interrelations between the fluoride concentrations in dental plaque and enamel, and exposure to fluoride.

The F concentrations in plaque and in underlying enamel were determined in a sample of 99 schoolchildren aged 8.4 years (S.D. = 0.37), comprising four groups, exposed life-long to contrasting concentrations of F in the water (range less than or equal to 0.12 ppm to 2.8 ppm) and to supplements of 350 mg F/kg domestic salt. The mean total F concentrations in plaque (dry wt) increased consistently with increasing exposure to F, but the absolute differences were small and the individual variation was high within each group. Significant inverse associations were demonstrated between individual plaque and surface enamel values within two groups, supported by consistent inverse trends (ns) in the remaining groups. These associations and trends are considered to reflect transfer of F from plaque to underlying surface enamel and concommitant reduction in plaque F concentration.