Abstract
Background: When dental plaque is not regularly removed, bacteria break down sugars in the diet forming acids as by-products. Lactic acid is the main acid involved in caries. As acids accumulate minerals are lost from the surface layer of the tooth. The imbalance in demineralization/remineralization favors the loss of calcium and phosphate from the teeth. Saliva contains the most important microelements for the remineralization and maturation of dental tissue and plays a crucial role in maintaining the oral environment. Fluoride is the agent par excellence in preventing and detaining cavities. However, remineralization may be hampered by limited levels of calcium and phosphate, and new products have been developed to ensure a constant supply. 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 salivary pH, lactic acid concentrations and trace elements.Methods: We conducted a controlled, randomized clinical trial where MI Varnish and Clinpro White Varnish were applied quarterly in children with a high risk of caries, for 12 months. We included 58 children aged 4-12 years, assigned to control (placebo), Clinpro and MI groups. Baseline and three-monthly saliva samples were taken. We assessed changes in pH, lactic acid concentrations and trace 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 24Mg (p= <0.001), 31P (p = 0.033) and 66Zn (p= 0.005) levels in the placebo group (p≤0.05), but not in the other elements studied: 23Na, 27Al, 39K, 44Ca, 52Cr, 55Mn, 57Fe, 59Co, 63Cu, 75As, 111Cd, 137Ba, 208Pb and 19F. Conclusions: Neither pH, lactic acid concentrations or most salivary trace 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-monthly application for 12 months. Trial registration: ISRCTN registry, ISRCTN13681286. Registered 26 May 2020.