Effect of Bonding with Self-etching Adhesives on Composite Interfacial Microleakage

OBJECTIVES: To evaluate microleakage of Class V resin-based composites bonded with one of seven self-etching adhesives; to study the interfacial microstructure using SEM. Methods: In 60 intact permanent premolars extracted for orthodontic reasons (12-18years), Class V cavities, approximately 3mmx 1.5mmx 2mm, were cut in both lingual and buccal surfaces using an ISO 010 diamond bur in a water cooled hand piece. Specimens were randomly assigned to eight groups (n=15 ) and a RBC (Tetric Ceram) was bonded with one of the following adhesives. Adper Prompt(3M ESPE), Clearfil SE(Kuraray), Prime& Bond NT(DeTrey), Xeno 111(DeTrey), One-Up Bond (Tokuyama), AdheSE (Ivoclar) or a control, PQ1(Optident), using a total etch technique. Specimens were stored in water (48hours), and thermocycled 5000 times in baths held at 50C and 550C. After immersion in 5% Procion Red (24 hours), specimens were sectioned and dye penetration scored using a 0-4 leakage scoring system. Specimens were then critically point dried and prepared for SEM,sputter coated in EMScope,SC500,viewed with a Philips 505SEM operating at 20Kv. Statistical analysis was performed using Kruskal-Wallis (Non-parametric ANOVA)at 95% significance level RESULTS: Gingival Scores*** AdperPmpt,1(4)2(6)3(5; Clearfil,1(5)2(8)3(1)4(1); P&BNT,1(5)2(4)3(5)4(4); Xeno 111, 1(3)2(11)3(1); One-Up,1(5)2(8)3(2); AdheSE,1(5)2(8)3(2); PQ1(control)1(8)2(2)3(5): Enamel Scores#### AdperPmpt,0(2)1(6)2(7); Clearfil,0(4)1(4)2(5)3(1)4(1); P&BNT,0(4)1(4)2(3)3(4); Xeno 111, 0(3)1(6)2(5)3(1); One-Up,0(5)1(4)2(5)3(1); AdheSE,0(1)1(3)2(5)3(1); PQ1(control)0(5)1(4)2(5)3(1):

**** No significant difference:p= 0.8153 ###No significant difference:p= 0.9765 SEM: Compared to the control (total-etch technique), self-etching materials produced a less well pronounced enamel etch and a thinner hybrid layer with less robust tag formation. CONCLUSIONS: Gingival leakage was observed in all specimens, self-etched or control. Reduced enamel acid-etch pattern observed with self-etching materials may contribute to increased leaking at enamel margins.