Effect of liquid dentifrices pH and fluoride concentration on caries control in a region with fluoridated water: randomized clinical trial

Low-F dentifrices have been suggested as an alternative to reduce the risk of dental fluorosis, although there is no consensus on their clinical efficacy, which may be increased when the pH is acidic.The present randomized clinical trial evaluated the anticaries effect of low-F acidic liquid dentifrice in children at different caries activity status. Two-to-four-year-old schoolchildren living in a fluoridated area (0.6 0.8 ppm F), with (A) or without (I) active caries lesions were randomly allocated into 3 groups differing according to the type of dentifrice used over 12 months: Group 1 (n=48-A/56-I): 550 ppm F pH 4.5, Group 2 (n=56-A/48-I) 1100 ppm F pH 7.0, Group 3 (n=52-A/55-I): 550 ppm F pH 7.0. The number of lesions becoming active/cavities or inactive was clinically evaluated determining progression or regression. Additionally, the white spot lesions were evaluated by the quantitative light-induced fluorescence (QLF) method in a subsample of 75 children. Toenail and plaque fluoride concentration were also evaluated 6 months after the use of the dentifrices. Plaque samples were collected 5 and 60 minutes after the last use of the dentifrices. Caries net increment followed a decreasing pattern according to the dentifrice used (G3>G2>G1) regardless caries activity, but significant differences were detected only for caries progression and net increment (G1 < G3) for the cariesactive group when evaluated through visual inspection. For the regression, the values found for the three groups were more similar, without significant differences. QLF analysis detected no significant difference between Groups 1 and 2, but they performed significantly better than Group 3. Toenail fluoride concentration significantly lower was observed when children used the low-fluoride dentifrices. Plaque F concentration was significantly higher for Group 2 compared to group 3, egardless the time, while Group 1 did not significantly differ Group 2, but was...