The effect of 25 years of water fluoridation in Newcastle assessed in four surveys of 5-year-old children over an 18-year period.

In 1994, the dental health of 496 5-year-old children who had lived in continuously fluoridated (at 1.0 mg F/litre) Newcastle was compared with the dental health of 436 children of the same age in non-fluoridated (less than 0.1 mg F/litre) south east Northumberland. The study also reported changes in the dental health of 5-year-old children in four surveys in these areas during the period 1976 to 1994. The mean dmft of children in the fluoridated area was 1.33 compared with 2.41 in the non-fluoridated area--a difference of 1.08 per child (45%). The corresponding dmfs scores were 2.80 in the fluoridated area and 5.77 in the non-fluoridated area--a difference of 2.97 tooth surfaces per child (52%). Thirty-nine per cent of children in the fluoridated area had experienced dental caries, compared with 55% in the non-fluoridated area. Only 10% of children in the fluoridated area had experienced dental caries in more than four teeth, compared with 22% in the non-fluoridated area. The prevalences of lifetime experience of toothache, extractions and general anaesthesia for dental extractions were greater in the non-fluoridated area than in the fluoridated area. When the results of this survey were compared with the results of similar surveys in the same areas in 1976, 1981 and 1987, it appeared that there has been a further reduction in dental caries levels following the levelling off observed between 1976 and 1981.