Effects of supervised daily dental plaque removal by children: first-year results

In September 1973, a three-year school-based study was initiated in East Hampton, Connecticut, a rural nonfluoridated community. The purpose of the study is to determine the effect on dental decay, gingival inflammation and oral hygiene of removing dental plaque through supervised daily toothbrushing and flossing in school during a three-year period. To establish baseline data, three indexes were used: the DHC Index to evaluate gingivitis; the DMF Surface Index to quantify dental caries and the PHP Index to measure dental plaque. The examinations for dental caries, including radiographs, are scheduled annually in September, whereas the plaque and gingival examinations are done biannually, in September and June. After the baseline examinations the 481 children were blocked according to grade and sex and then were randomly assigned to either a treatment group or to a control group. In November, the treatment group was provided 10 sessions of instruction in plaque removal. For the remainder of the year (six months) they practiced daily plaque removal, supervised by a dental hygienist and a nurse. The control group was not instructed in oral hygiene procedures. In the treatment group, mean plaque and gingival scores at the June (first follow-up) examination were 14 percent and 29 percent lower, respectively, than at baseline. No change was seen in the control group. At the second follow-up examination in September (after summer vacation), the same indexes were nearly at baseline levels in the treatment group. There was no treatment effect on dental caries increments after one year of study. Considering the nature of the treatment regimen and the few treatments during the first year of the study, it is not surprising that there were no caries-preventive benefits demonstrated among children in the treatment group after one year. The total number of the plaque removal sessions will be greater during the second year of the study. Therefore, the possibility of detecting a caries preventive effect at the twenty-four month examinations, should one exist, will be enhanced.