Protecting Root Surfaces from Demineralization Utilizing Dentin Bonding

Protecting exposed root surfaces from acid attack may provide a method of protecting root surfaces from dental caries. Utilizing dentin bonding agents may provide that protection. Objectives: This study examines whether a dentin bonding agent can protect the root surface from demineralizing under acid attack. Materials and Methods: The root surfaces of 5 freshly extracted bovine teeth were cleaned, embedded in acrylic resin and surface smoothed with 600 grit sandpaper. Vickers microhardness values were initially obtained (10 g load) on the surface of each tooth (Mesial, Central and Distal readings)utilizing a Leco Microhardness Tester (St. Joseph, Michigan). Half of each root surface was then coated with Peak SE Primer and Peak LC (Ultradent, South Jordan Utah) bond resin according to the manufacturers' instructions and the other half remained untreated. Subsequently, all specimens were submerged in artificial caries solution as described by Featherstone at pH 4.0 for 4 hours. The 5 demineralized root surfaces were sectioned into quarters utilizing a diamond disc. Microhardness of the respective demineralized areas and areas coated with dentin bonding agent was determined using Vickers microhardness measuring the cross section just beneath the dentin and bonding surfaces. 3 readings were taken on each of the resulting 10 non-treated and 10 Peak SE Primer/Peak LC bond treated root surfaces. Microhardness values were analyzed utilizing ANOVA. Results: Microhardness of pre-demineralized dentin and dentin protected by bonding agent were the same (no statististical difference). Dentin exposed to demineralization solution without dentin bonding agent protection was significantly softer with a microhardness ¼ the baseline microhardness. Conclusion: Dentin bonding agents may protect root surfaces from acid attack and prevent the development of caries lesions of the root or acid erosions.