In vitro comparison of orthodontic band cements

The aim of the study was to compare the mean retentive strength of microetched orthodontic bands cemented to extracted human third molars with a modified composite, a resin-modified glass ionomer cement, and a conventional glass ionomer cement. The mode of band failure and amount of cement remaining on the tooth at deband were also assessed. Finally, survival time of bands with each cement was assessed with simulated mechanical stress in a ball mill. Ninety banded specimens were used to assess retentive strength, and another 30 banded specimens were used to assess survival time. The mean retentive strength of the modified composite (0.415 MPa) was significantly less than that of either the resin-modified (1.715 MPa) or the conventional glass ionomer cement (1.454 MPa; P <.001). Specimens failed predominantly at the cement-enamel interface. The amount of cement remaining on the tooth at deband differed significantly between bands cemented with the resin-modified cement and those cemented with the conventional glass ionomer cement (P <.05). Mean survival time of bands cemented with the resin-modified glass ionomer cement (14.3 hours) was significantly longer (P <.01) than for bands cemented with the conventional glass ionomer cement (9.9 hours) but did not differ significantly from that of bands cemented with the modified composite (11.1 hours; P >.05). Orthodontic bands cemented with the modified composite appear to have a significantly lower mean retentive strength than bands cemented with resin-modified or conventional glass ionomer cement, but mean survival time did not differ significantly for bands cemented with modified composite or resin-modified glass ionomer.