A new method for studying the effect of glass ionomer on plaque in vivo.

In order to study the amount of fluoride originating from glass ionomer, a test appliance was constructed and set on upper molars of sixteen volunteers using glass ionomer. The control appliance was set on the contralateral tooth using composite. Six weeks after the setting of appliances, plaque samples were taken and analysed. Mean amounts of protein corresponding to the amounts of plaque were equal in the test and the control groups. The mean fluoride/protein ratio in plaque was 80 times higher in the glass ionomer group than in the composite group. With this sampling method it is possible to collect sufficient amounts of plaque for quantification of plaque fluoride.