Influence of aluminum oxalate solutions acidity and conditioning times on resin bond strength to enamel.

The present investigation demonstrated that variations in pH between 0.8 and 2.1 and in the duration of etching with an aluminum oxalate/glycine conditioning solution between 5 and 120 seconds has no influence on the retentive strength of restorative polymer to enamel, although the micromorphological appearance of enamel is clearly affected. The lower the pH of and the longer the etching time with the conditioning solution, the more pronounced is the roughness pattern generated. SEM inspection of the fracture sites following debonding of shear bond strength specimens verified consistently cohesive failure in resin close to the interface.