A METHOD FOR STUDY OF ACID PRODUCTION BY SALIVARY SEDIMENTS

¹ Tufts College Dental School, Boston, Mass.

Equipment has been assembled and tested for study of the rate of acid production by sediment obtained from whole saliva using an in vitro system which permits control of some of the important variables. Paraffin-stimulated saliva is centrifuged for twenty minutes at 2,400 r.p.m., and 0.1 ml. of the precipitate obtained therefrom is held in contact with a glass electrode by means of a thimble of nylon mesh. The sediment derived from the saliva of some persons forms acid rapidly and reaches an equilibrium pH about 2 units below that of the solution in contact with the sediment. This solution contains 0.2 molar glucose and 0.01 molar CO₂-NaHCO₃ buffer. Influence of inhibitors can be observed from their effect on the pH differential at equilibrium. Agitation and buffer capacity of the solution have been shown to be factors capable of affecting the equilibrium pH.