1c:I[419806,["/_next/static/chunks/bb923814e1f4d2e9.js","/_next/static/chunks/dd3ee9f5b7716ca6.js","/_next/static/chunks/4204a0ae82542ca8.js","/_next/static/chunks/30036bedc5269936.js","/_next/static/chunks/6e1aa89a642f40be.js","/_next/static/chunks/cd5e572bc3e4eb92.js","/_next/static/chunks/8ffd0b71567920d8.js","/_next/static/chunks/67ea6dfd21f16c5f.js","/_next/static/chunks/24eb4379f68013fd.js","/_next/static/chunks/b8cd775ffdf935bd.js","/_next/static/chunks/983103cd9eb7b428.js","/_next/static/chunks/d4ac9dcf27f6ff52.js","/_next/static/chunks/294b9525248c8e5f.js"],"default"] 1d:T45e,A method using an Orion combination electrode (96–09) was developed for determining the total fluoride content of soft tooth deposits. The samples were collected by plastic sealers and dried at 105° C. After weighing, the sample was dissolved in a small polypropylene tube, positioned inside a larger tube. The dissolution was carried out in 0.2 ml of a mixture of HClO₄ and HNO₃ at 60° C for 2 h. The outer tube contained 0.3 ml NaOH and 1 ml Na₃-citrate. After the soft deposit was dissolved, the contents of the tubes were mixed without opening the sealed outer tube. The final mixture had a pH of 5.8 and the F^–– was determined directly. The recovery was found to be satisfactory. Known amounts of F added to dried deposits of Streptococcus salivarius and to Ca₃(PO₄)₂ indicated no F- binding in the solubilized material. Deposits collected from a group of children 5–6 days after mouthrinsing with 0.2 % NaF had an average fluoride concentration of 85 ppm F (on dry weight) as compared to 52 ppm F in the control group.1e:T482,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.

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