Amorphous calcium phosphate-containing orthodontic cement for band fixation: an in vitro study.

Abstract

Aim: To evaluate the shear bond strength (SBS) and fracture mode of amorphous calcium phosphate (ACP)-containing and conventional glass-ionomer cement (GIC) for band fixation.

Methods: Sixty extracted human third molars were embedded in acrylic resin blocks, leaving the buccal surface of the crowns parallel to the base of the molds. The teeth were randomly divided into two groups containing 30 teeth each. GIC (group 1, Ketac-Cem) or ACP-containing orthodontic cement (group 2, Aegis-Ortho) was applied onto microetched strip band material (4.0 × 3.8 mm), which was then attached to the tooth surfaces. With a universal testing machine, each cemented band strip was shear mode loaded until failure. Thereafter, all teeth and band strips were examined under 10× magnification. The remaining cement was assessed with a modified Adhesive Remnant Index (ARI). The SBS data were analyzed using the t test and the fracture modes by the chi-square test.

Results: There was no significant difference between the bond strength of group 1 (GIC, mean: 28.9 ± 15.2 MPa) and group 2 (ACP-containing cement, mean: 26.3 ± 11.8 MPa). The fracture modes differed significantly between the two groups (P<.01).

Conclusion: Both groups had a similar level of SBS. The fracture sites of the ACP-containing cement were predominantly in the enamel-cement interface.