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.

No abstract

No abstract

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.

No abstract

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.

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.

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.