EFFECTIVENESS OF CALCIUM LACTATE ADDED TO FOOD IN REDUCING INTRAORAL DEMINERALIZATION OF ENAMEL

Following the demonstration that rinses with solutions of soluble calc ium salts reduced sucrose-induced demineralization, a study was undert aken to determine whether a similar effect could be obtained by the su pplementation of a solid food with calcium lactate (CL). Subjects wore palatal appliances containing blocks of bovine enamel that were coate d with Streptococcus mutans IB 1600 and ate 5-gram portions of cookies made with defined levels of CL. Determinations were made of changes i n iodide penetrability (Delta Ip) of the enamel, as well as the pH, ca lcium and inorganic phosphate of the streptococcal plaque. CL at 3.2% (w/w) reduced Delta Ip from 12.9+/-1.7 to 6.1+/-0.9 units, i.e. by 52. 7%. Plaque pH was not affected. Demineralization was reduced progressi vely with increasing concentrations of added CL, and CL was most effec tive with increasingly sweet cookies. Plaque contained 32.4+/-6.0 and 17.1+/-4.2 mM calcium after 1 and 5 min, respectively. Calculations sh owed that the plaque was saturated with respect to enamel during the f irst 5-10 minutes after food ingestion, in spite of the progressive dr op in plaque pH. In conclusion, the present study demonstrated the red uction of the cariogenic potential of solid food by relatively low con centrations of CL. The effect appeared to be related to the ability of the food to maintain high levels of calcium in the streptococcal plaq ue during the period of active acidogenesis.