Zahran M
Community Dent Oral Epidemiol. 1976 Nov;4(6):240-3. doi: 10.1111/j.1600-0528.1976.tb00991.x.
A 4-year clinical trial was conducted to determine the effect on dental caries incidence of the use of acidulated phosphate fluoride (APF 1.23%). 1,653 Egyptian schoolchildren aged 8 years started the trial. Dental caries was assessed annually by clinical examinations. 1,027 children completed the study. After 4 years, the children in the study group showed a mean of 2.58 DMF teeth and 2.68 DMF surfaces. Those in the control group showed 2.58 and 2.67, respectively. No significant reduction in the caries increment was observed at 0.05 level. The findings of this study suggest that topical application of fluoride does not decrease pit and fissure caries.