Title:  Effect of different surface pre-treatment methods on the microleakage of two different self-adhesive composites in Class V cavities

Abstract:  Aim To evaluate the effect of different surface pre-treatment methods on the microleakage of self-adhesive flowable composites (SAFCs) in comparison with a conventional flowable composite applied with an etch-and-rinse adhesive system. Materials and methods One hundred and thirty-five standardised Class V cavities were randomly divided into nine groups: (1) three-step etch-and-rinse adhesive (Optibond FL - Kerr, Orange, USA)/flowable composite (Clearfil Majesty Flow - Kuraray, Tokyo, Japan) (E&Ra/flowC); (2) Fusio Liquid Dentin (Pentron Clinical, Orange, USA); (3) Er:YAG Laser/Fusio Liquid Dentin (Er&Las/Fusio Liquid Dentin); (4) Phosphoric Acid/Fusio Liquid Dentin (PhosA/Fusio Liquid Dentin); (5) Polyacrylic Acid/Fusio Liquid Dentin (PolyA/Fusio Liquid Dentin); (6) Vertise Flow (Kerr, Orange, USA); (7) Er:YAG Laser/Vertise Flow (Er&Las/Vertise Flow); (8) Phosphoric Acid/Vertise Flow (PhosA/Vertise Flow); (9) Polyacrylic Acid/Vertise Flow (PolyA/Vertise Flow). After thermocycling and immersion in a 0.5% basic fuchsin, the restorations were evaluated under a stereomicroscope (n = 30). The data were statistically analysed (a = 0.05). Results Both SAFCs showed higher leakage scores than E&Ra/flowC in enamel and dentin (p < 0.05). Vertise Flow showed lower leakage than Fusio Liquid Dentin in dentin (p<0.05). Pre-phosphoric acid etching reduced the microleakage scores of Fusio Liquid Dentin in both enamel and dentin (p < 0.05), while all surface pre-treatment methods led to a significant reduction in the microleakage scores of Vertise Flow at the enamel margin (p < 0.05). Conclusion Pre-etching of enamel and dentin by phosphoric acid may be satisfactory in improving the sealing ability of Fusio Liquid Dentin, while phosphoric acid or polyacrylic acid etching or laser irradiation may be used to improve the adhesion of Vertise Flow to enamel.