Effects of Fluoride and Calcium Phosphate-Based Varnishes in Children at High Risk of Tooth Decay: A Randomized Clinical Trial

Background: The aim of this study was to investigate the effect of the application of two varnishes—MI Varnish (5% sodium fluoride with CPP-ACP) and Clinpro White Varnish (5% sodium fluoride with fTCP)—applied every three months in children with high caries risk for 12 months on plaque indexes, salivary pH, salivary lactic acid and chemical elements concentrations. Methods: We included 58 children aged 4–12 years, assigned to control (placebo), Clinpro and MI groups. Baseline and three-month saliva samples were taken. We assessed changes in pH, lactic acid concentrations and chemical elements in saliva. Results: At 12 months, all groups showed a nonsignificant increase in pH levels and a reduction in lactic acid, which was greatest in the placebo group. There was a significant reduction in (24)Mg (p = <0.001), (31)P (p = 0.033) and (66)Zn (p = 0.005) levels in the placebo group (p ≤ 0.05), but not in the other elements studied: (23)Na, (27)Al, (39)K, (44)Ca, (52)Cr, (55)Mn, (57)Fe, (59)Co, (63)Cu, (75)As, (111)Cd, (137)Ba, (208)Pb and (19)F. Conclusions: Neither pH, lactic acid concentrations or most salivary chemical elements were useful in defining patients at high risk of caries or in monitoring the effect of MI Varnish and Clinpro White Varnish after three-month application for 12 months. However, the appearance of new cavities was stopped, and the hygiene index improved, probably due to hygienic and dietary measures and the use of fluoridated toothpaste. Trial registration: ISRCTN registry, ISRCTN13681286.