Laboratory evaluation of a compomer and a resin-modified glass ionomer cement for orthodontic bonding

The mean shear debonding force of stainless steel orthodontic brackets with microetched bases bonded with either a compomer or a resin-modified glass ionomer cement was assessed. In addition, the amount of cement remaining on the enamel surface following bracket removal was evaluated. Finally, survi val time of orthodontic brackets bonded with these materials was assessed f ollowing simulated mechanical stress in a ball mill. Debonding force and su rvival time data were compared with those obtained for brackets bonded with a chemically cured resin adhesive, a light-cured resin adhesive, and a con ventional glass ionomer cement. There were no significant differences in me an shear debonding force of brackets bonded with the compomer, resin-modifi ed glass ionomer, chemically cured resin adhesive, or the light-cured resin adhesive. Brackets bonded with a conventional glass ionomer cement had a s ignificantly lower mean shear debonding force than that recorded for the ot her materials. The Adhesive Remnant index (ARI) mode score indicated that s ignificantly less cement remained on the enamel following de bonding of bra ckets cemented with resin-modified or conventional glass ionomers compared with other adhesives. The median survival time for brackets cemented with t he compomer, resin-modified glass ionomer, chemically cured resin, or light -cured resin were significantly longer than for brackets cemented with conv entional glass ionomer. The compomer and the resin-modified glass ionomer a dhesive appear to offer viable alternatives to the more commonly used resin adhesives for bracket bonding.