Calcium Prerinse before Fluoride Rinse Reduces Enamel Demineralization: An in situ Caries Study.

A calcium (Ca) prerinse before a fluoride (F) rinse has been shown to increase oral F levels. We tested the anticaries effect of this combination in a dose-response in situ caries model. In a double-blind, crossover experiment, 10 volunteers carried enamel slabs in palatal appliances for 14 days, during which they rinsed twice/day with one of four rinse combinations: (1) a placebo prerinse (150 mM sodium lactate) followed by a distilled water rinse (negative control); (2) a placebo prerinse followed by a 250 ppm F rinse; (3) a placebo prerinse followed by a 1,000 ppm F rinse, or (4) a Ca prerinse (150 mM Ca, as calcium lactate) followed by a 250 ppm F rinse. Sucrose solution was dripped onto the slabs 8×/day to simulate a high cariogenic challenge. The percent surface hardness loss (%SHL) was significantly lower in the Ca prerinse used with the 250 ppm F rinse group (%SHL = 38.0 ± 21.0) when compared with the F rinse alone (%SHL = 59.5 ± 24.1) and similar to the 1,000 ppm F rinse group (%SHL = 42.0 ± 18.3). Compared with the 250 ppm F rinse, the Ca prerinse increased biofilm fluid F only twice (nonsignificant). However, it greatly increased F in biofilm solids (∼22×). The Ca prerinse had little effect on loosely or firmly bound enamel F. The results showed an increased level of protection against demineralization by the use of a Ca prerinse, which seems to be caused by the enhancement of F concentration in the biofilm.

Oral fluoride levels 1 h after use of a sodium fluoride rinse: effect of sodium lauryl sulfate.

Increasing the concentration of free fluoride in oral fluids is an important goal in the use of topical fluoride agents. Although sodium lauryl sulfate (SLS) is a common dentifrice ingredient, the influence of this ion on plaque fluid and salivary fluid fluoride has not been examined. The purpose of this study was to investigate the effect of SLS on these parameters and to examine the effect of this ion on total (or whole) plaque fluoride, an important source of plaque fluid fluoride after a sufficient interval following fluoride administration, and on total salivary fluoride, a parameter often used as a surrogate measure of salivary fluid fluoride. Ten subjects accumulated plaque for 48 h before rinsing with a 12 mmol/l NaF (228 µg/g F) rinse containing or not containing 0.5% (w/w) SLS. SLS had no statistically significant effect on total plaque and total saliva fluoride but significantly increased salivary fluid and plaque fluid fluoride (by 147 and 205%, respectively). These results suggest that the nonfluoride components of topical agents can be manipulated to improve the fluoride release characteristics from oral fluoride reservoirs and that statistically significant change may be observed in plaque fluid and salivary fluid fluoride concentrations that may not be observed in total plaque and total saliva fluoride concentrations.