Identification and preventive care of high caries-risk children: a longitudinal study.

A method of identifying high caries-experience children to participate in a mouthrinsing programme was tested. Children aged 9 to 12 years were assigned into high and low caries-risk groups using caries experience in the deciduous dentition and a clinical lesion on the occlusal surface of a first permanent molar within 2 years of eruption as indicators of risk. There were 273 high caries-risk children (101 in the fluoride rinse group, F, and 172 in the placebo rinse group, P); in the low caries-risk group, L, there were 648 children. After 5 years there were differences in the caries experience in the permanent dentition of the high and low caries-risk groups P and L. The high caries-risk group P had mean DMFT and DMFS scores of 2.7 and 3.2 respectively compared with 0.4 for both indices for the low caries-risk group, L. Most lesions occurred on occlusal surfaces. Caries experience was accurately predicted for 87 percent of the children when a DMFT score equal to or greater than 3 was used as the criterion of high caries experience. Accuracy was greater for the low caries-risk group (96 percent) than for the high caries-risk group (51 percent). Similarly the proportion of low caries-experience children identified in the low caries-risk group was greater than the proportion correctly identified in the high caries-risk group. When a DMFS score equal to or greater than 4 was used, there was little change. This method of prediction provided a practical method of identifying groups of children in need of special preventive care. Fortnightly mouthrinsing with 0.2 percent sodium fluoride solution was tested as a preventive measure for half the high caries-risk children (group F); the control group, P, used a placebo rinse. There were no significant differences in the caries scores of the two groups at the end of the study. Mouthrinsing was an ineffective preventive measure for high caries-risk children in this study.