The silver leakage in dentin bonding interface of dental fluorosis

Objective: The objective of this study is to to study the effects of dental fluorosis degree on the leakage of resin-dentin bonding interfaces.Methods: Twelve posterior teeth without caries or attrition were divided into 3 groups based on the degree of fluorosis(Dean index). The occlusal dentin was exposed and the prepared surface was separated into two parts that was bonded then with two bonding agents, Prime&Bond NT and Contax, respectively. After applying bonding agents, a layer of composite resin was covered on the bonding agent and photo-polymerized. Then the specimens were immersed in ammoniacal silver nitrate solution for 24hrs, followed by immersed in developing solution for 8 hrs. Finally the teeth were sectioned into pieces longitudinally and the silver leakage depth alone bonding interface was observed and measured under SEM. Results:The leakage depth of 3 groups for Prime&Bond NT was 339.33+-92.68um‚335.06+-96.59um‚and 708.16+-131.55um‚respectively;that for Contax was 264.00+-96.32um‚401.44+-92.34um‚and 618.86+-165.95um‚respectively. Conclusions:For the same bonding agents, the leakage depth of the teeth with severe fluorosis was statistically higher than that with mild and moderate fluorosis. However, there was no statistical difference between Prime&Bond NT and Contax in the same group.