The impact of dental varnishes on the immediate surface microhardness and roughness of restorative dental materials: An in vitro study

Abstract

Background/Aim. Dental caries is a multifactorial disease that ultimately results in the demineralization of dental tissues and is recognized by the World Health Organization as the most prevalent disease among the global population. Dental varnishes are effective in preventing caries in children. The aim of this study was to investigate the way in which dental varnishes, one of which contained fluoride and the other casein phosphopeptideamorphous calcium phosphate (CPP-ACP), affect the microhardness and roughness of the three most commonly used restorative materials in pediatric dental practice [resin-modified (RM) glass ionomer cement (GIC), high-viscosity (HV) GIC, and micro-hybrid composite (MHCOMP)]. Methods. The study included 60 discs and 60 bars, of which 20 discs and 20 bars each were made from one of the three commonly used dental restorative materials. After preparation, incubation, and subsequent basic measurement, the samples were divided into two subgroups (each subgroup containing 30 discs and 30 bars), and each of them was treated with fluoride or CPP-ACP varnish according to a precisely established protocol. After treatment with varnishes, all samples were retested for microhardness and roughness. Results. The application of fluoride or CPP-ACP varnish in-creased the microhardness of the MHCOMP and RM GIC but reduced the microhardness of HVGIC. The roughness was more pronounced with the composite material, as well as with the RM GIC. Conclusion. Prophylactic varnishes containing fluoride and calcium have the potential to alter the microhardness and roughness of dental restorations; that is why carefully selecting the appropriate varnish is important.