Effect of post-brushing water rinsing on caries-like lesions at approximal and buccal sites

The aim was to study the effect of two different water rinsing procedures after toothbrushing with an NaF-containing dentifrice on the degree of de- or remineralization of enamel and dentine at approximal and buccal sites. Seven adults, wearing complete dentures, participated in two experimental periods (A and B) in a randomised order. During period A, they brushed with the dentifrice for 2 min, followed by 1-min active mouthrinse with the toothpaste-foam combined with 10 ml of water. No more water was used after the slurry had been spat out. During period B, the brushing was followed by 3 thorough rinsings of approximately 15 ml water each. These two procedures were carried out twice daily, i.e. in the morning (after breakfast) and in the evening (just before bedtime), during 3 months. Demineralized enamel and dentine samples were mounted at two locations--approximally and buccally--in the first molar region of the upper prostheses. Quantitative microradiography (TMR) was used to assess the lesion depth (ld) and the mineral loss (delta Z). The results showed that the approximally located samples continued to lose mineral during both periods A and B. However, the ld and delta Z values for enamel (p < 0.01) and dentine (p < 0.05) increased less during A than B. The buccally located enamel and dentine samples remineralized during the experiment, but no statistically significant differences were found for the ld and delta Z values of either enamel or dentine between periods A and B.(ABSTRACT TRUNCATED AT 250 WORDS)