Objectives: To assess the effects of different mechanisms of enamel conditioning on the bonding performance of auto-adhesive luting cements to enamel. Methods: Flat enamel surfaces from forty-eight human molars were divided in four treatment groups: 1) no treatment (control); 2) etching with 36% H3PO4 for 15s; 3) etching with 0.1M EDTA for 60s; and 4) etching with Clearfil SE Bond Primer for 20s. Composite blocks (Tetric Ceram/Ivoclar Vivadent) were cemented to the treated enamel surfaces with the self-adhesive resin cements RelyX Unicem (3M ESPE), Maxcem (Kerr) and Multilink Sprint (Ivoclar), according to the manufacturer's instructions. Bonded specimens were sectioned into beams of 1.0 mm2 cross-sectional area for microtensile bond strength (µTBS) evaluation. Beams were stressed in tension at 0.5 mm/min. Data were analyzed by 2-way ANOVA and Tukey test (α=0.05). Results: Mean µTBS and standard deviations are listed (MPa). Within the same row, identical letters indicate no differences (P<0.05).
| Control | H3PO4 | EDTA | SE Bond Primer | TOTAL |
RelyX Unicem | 5.7 (1.8) ef | 22.4 (6.3) b | 12.3 (2.4) de | 11.1 (2.0) de | 12.8 B |
Maxcem | 8.0 (1.0) def | 28.1 (4.9) a | 1.5 (0.3) f | 17.9 (3.1) c | 13.8 AB |
Multilink | 14.8 (1.3) cd | 22.7 (2.8) b | 9.8 (1.4) def | 14.5 (1.7) cd | 15.5 A |
TOTAL | 9.5 C | 24.4 A | 7.8 C | 14.5 B |
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