Abstract
We previously showed that fluoride remains in dental plaque after a single mouth rinse with an NaF solution (250 ppm fluoride) and inhibits production of lactic acid following a glucose rinse. However, the rise in fluoride level due to NaF rinse is only temporary and unlikely to have long-term effects. On the other hand, Pearce et al. reported that fluoride remained in dental plaque for many hours after an ME-MFP rinse. In the present study, we examined the effects of an ME-MFP (250 ppm fluoride) rinse on production of lactic acid following a glucose rinse. The fluoride level measured after ME-MFP rinse followed by glucose rinse 30 minutes later (short-interval group) was 23.4 ppm, while that after ME-MFP rinse followed by glucose 5 hours later (long-interval group) was 14.6 ppm. The fluoride level in the control group was 4.8 ppm. The calcium level was 450.8 ppm and 339.7 ppm in the short- and long-interval groups, respectively, while that in the control group was 79.1 ppm. The difference in fluoride and calcium levels was statistically significant (p＜0.05) between the short-interval and control group, but not between the long-interval and control group. Furthermore, lactic acid was 91.8 ppm and 126.5 ppm in the short- and long-interval groups, respectively, while that in the control group was 147.0 ppm, with no significant differences among the groups. Our findings showed that an ME-MFP rinse increases fluoride and calcium levels, especially when applied shortly before a glucose rinse. However, no inhibitory effect of rinsing with ME-MFP on lactic acid production was confirmed.
