Factors related to fluoride retention after toothbrushing and possible connection to caries activity.

The aim of the present investigation was to study the brushing and toothpaste technique employed by caries-active and caries-inactive patients in a toothbrushing population. The study consisted of 47 patients at a public dental clinic in the County of Bohuslän, Sweden; 23 with low (group L) and 24 with high caries activity (group H). They were asked to brush their teeth with a fluoride dentifrice at the clinic using an identical technique to that which they employed at home. Various factors, such as brushing time, amount of dentifrice, water consumption and mouthrinsing habits after brushing, were carefully registered. Saliva samples for fluoride analyses were collected up to 45 min after brushing. The members of group L used less rinsing water (0.7 +/- 0.6 dl; mean +/- SD) than those of group H (1.9 +/- 1.0 dl, p < 0.001). Comparing the mouthrinsings with water after the brushing, a significantly higher frequency was observed in group H (3.6 +/- 1.9 rinsings) than in group L (1.5 +/- 0.7 rinsings; p < 0.001). There were no differences between the two groups regarding the amount of dentifrice used and the total brushing time. When the salivary fluoride concentration was plotted vs. time and the area under the curve (AUC) calculated, a significantly higher mean value was found in group L than in group H (p < 0.01). Calculation of the correlation coefficient (r) between the AUC value and the amount of water used gave r = 0.53 (p < 0.001) and between the AUC and the frequency of mouthrinsing r = 0.46 (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)