Effect of a resin infiltrant on white spot lesions treatment: in vitro, in situ and in vivo analyses

Abstract

Caries is a multifactorial disease that causes lesions on dental hard tissues ranging from incipient ultrastructural compromising level, up to total destruction of mineralized tissues. Currently, regarding the minimally invasive dentistry, it is of concern to treat and paralyze these early lesions interrupting its advance and avoiding more invasive treatment. There are several approaches to the treatment of these lesions and, more recently a resin agent was introduced with potential to infiltrate into the pores of caries-affected enamel, to stop and preventing its progression. This caries infiltrant is known by the trade name of Icon®. This project aims to evaluate the effect of Icon ® on artificial caries lesions produced by different protocols, and efficiency of this treatment after new acid challenge under in vitro and in situ experimental models, by means of superficial and longitudinal microhardness. The clinical effectiveness will be evaluated by a randomized controlled clinical trial comparing the use of infiltrant with fluoride varnish in white spot lesions. For the in vitro step, artificial caries lesions will be produced in 90 bovine enamel specimens through three different protocols (MC gel, MHDP solution and pH cycling). The specimens will be treated with infiltrant and subjected to acid challenge by new pH cycling. Superficial and longitudinal microhardness of specimens will be evaluated at three times: after demineralization by different protocols, after treatment with the infiltrant and after the new acid challenge. For the in situ step, 12 volunteers will participate, which will use palatal appliances containing four bovine enamel specimens for 14 days. During this period, volunteers will drop sucrose solution 8 times/day on specimens. Superficial and longitudinal microhardness of the specimens will be evaluated at three times: after demineralization, after treatment with the infiltrant and after the new acid challenge in situ. For clinical evaluation, assessments will be conducted directly and through photography, both following the modified criteria of Gorelick, Geiger and Gwinnett (1982) and ICDAS-II index. The use of QLF, as complement response, also will be used in the evaluations at the following times: immediately, 1 week, 4 and 8 weeks after the treatment. Data will be collected and statistically analyzed according to the distribution that will be checked. (AU)