Effects of two different treatments on enamel structure and bond strength of orthodontic brackets / 中国组织工程研究

ABSTRACT

BACKGROUND:There are two ways to treat the enamel before bracket bonding etching and sandblasting, but the few studies focus on the direct use of sandblasting technology on untreated enamel surface. OBJECTIVE:To observe the damage of etchingversus sandblasting to the enamel surface, and to compare the bonding strength of metal brackets adhesive to isolated teeth with these two kinds of surface treatments. METHODS:(1) Nine premolar teeth removed for orthodontic treatment were randomized into three groups sandblasting, acid etching and polishing treatment groups. Surface roughening effects of these three kinds of treatments were observed under scanning electron microscope. (1) Another 40 premolar teeth removed for orthodontic treatment were randomized into two groups sandblasting and acid etching groups. At 24 hours after bracket bonding, the shear strength was detected using mechanical testing machine, and the adhesive residue index of tooth surface was statisticaly calculated. RESULTS AND CONCLUSION: (1) Under the scanning electron microscope, polishing treatment had no damage to the enamel surface; but in the other two groups, the enamel surface was damaged to varying degrees, especialy in the sandblasting group. (2) The bonding strength in the sandblasting group was significantly higher than that in the acid etching group (P 0.05). These findings indicate that compared with the acid etching technology, the sandblasting technology can increase the bonding strength between the enamel and metal bracket, but it also results in more damage.