Sandblasted metal brackets bonded with resin-modified glass ionomer cement in vivo

The aim of this in vivo study was to evaluate the effects of sandblasting metal brackets on their clinical performance when resin-modified, chemically cured glass ionomer cement was used for bonding. A total of 60 patients with a range of malocclusions were allocated randomly into two groups. For the first 30 cases, teeth were divided into quadrants so that sandblasted, mesh-based metal brackets (SB) were bonded directly to the upper left and lower right quadrants using the resin-modified glass ionomer cement. The mesh-based (no sandblasting) brackets bonded to the other quadrants with the same adhesive were used as control (CO). A split-mouth design was used, and the allocation of the brackets per quadrant was reversed for the second 30 cases. Sandblasting of the bracket bases was accomplished using 25-microm aluminum oxide particles for three seconds. The manufacturer's instructions were followed for bonding. The number, site, and date of first-time bracket failures were monitored throughout active orthodontic treatment, and the observation time was 20 months. The bond failure rates were 4.9% and 4.3% for the SB and CO brackets, respectively. No statistically significant difference was found between the groups for failure rates. The bond failure sites were predominantly at the enamel-adhesive interface in both groups. Sandblasting did not have a positive effect on the clinical performance of the mesh-based metal brackets when bonded with resin-modified glass ionomer cement.