Microleakage and Confocal Laser Studies of Self-etching Bonding Agents

Objectives: This study investigated the microleakage, etching ability and dentine-restorative interface of two different single step self-etching bonding agents with compomers as restoratives. Materials and Methods: Fifteen extracted non-carious human premolars were used for each dental material system. The bonding agent Xeno III was used with their compomer Dyract AP (Dentsply) and Adper Prompt L-Pop with their compomer Z2000 (3M ESPE). Cylindrical cavities were prepared in enamel and dentine on the buccal surface at the cemento-enamel junction and restored. The coronal half was in the enamel and the apical half in the dentine. The specimens were thermocycled, cut into slices and the depth of dye penetration scored. Results: Microleakages between the enamel and dentine sides differed significantly for Xeno (Wilcoxon Rank Sum test; p=0.0058) as well as Prompt (p=0.0106), while the microleakages between the dentine sides of Xeno and Prompt did not differ (p=0.50) significantly. However, between the enamel sides a significant difference was found (p=0.000) with the highest value for Prompt. The confocal laser studies showed tag formation, penetration of the bonding agents deep into the tubules, and hybrid layer formation for both bonding agents. Conclusion: Thus, it can be concluded that both (Xeno III and Adper Prompt L-Pop) single step self-etching dental adhesives gave good microleakage values rated in the higher class when compared to previous bonding agents. However, careful inspection of the enamel side indicated that sealing of enamel is not good enough and here Xeno III was the better of the two.