@article{villena_tenuta_cury_2009,  title={Effect of APF gel application time on enamel demineralization and fluoride uptake in situ},  volume={20},  ISSN={0103-6440},  url={https://doi.org/10.1590/S0103-64402009000100006},  DOI={10.1590/S0103-64402009000100006},  number={1},  journal={Brazilian Dental Journal},  publisher={Fundação Odontológica de Ribeirão Preto},  author={Villena, Rita Sarmiento and Tenuta, Livia Maria Andaló and Cury, Jaime Aparecido},  year={2009},  pages={37–41} }