Nagaviroj, Noppavan, Nichaphat Kotnarin, and Widchaya Kanchanavasita. 2018. “The effect of staining solutions on the color stability of the provisional restorative materials”. Mahidol Dental Journal 38 (3). Bangkok, Thailand:205-12. https://he02.tci-thaijo.org/index.php/mdentjournal/article/view/179129.