The effect of ingesting boiled sweets (candies) supplemented with 3% dicalcium phosphate dihydrate on dental plaque composition was investigated in 5 separate studies. Regular exposure to experimental sweets during the 1st 48 h of plaque formation was associated with higher Ca and Pi concentrations in plaque than similar exposure to control sweets. No differences were apparent when mature plaque from subjects consuming experimental or control sweets for a period of 1 yr was investigated. The effect on plaque composition of a single exposure to the experimental sweet was not significantly different from that of exposure to the control sweet in 2 day plaque of young adults or mature plaque of children.