The effect of altering the position of a sugary food in a meal upon plaque pH in human subjects.

Plaque pH in six adult subjects was monitored while they consumed a meal containing three foods. The marked fall in plaque pH caused by drinking sugared coffee was considerably reduced by eating the two non-sugary foods (egg and crisp-bread) before, during, or after the sugared coffee. This favorable action was negated by a pause between the sugary and non-sugary courses.