Abstract: Objective To evaluate the laser aided debonding and the degree of staining of the teeth surface. Methods 30 healthy premolars extracted from January 2014 to January 2016 in our hospital were selected as the research objects. A month later, the teeth were randomly divided into three groups (A,B and C):group A using laser and silicon particles to bracket, group B using bracket forceps, silicon particle, group C was debonded using bracket forceps, tungsten carbide drill, and silicon particle. Results The operation time of statistics in group C was shortened obviously compared with group B. After the removal of the brackets on the three groups of enamel loss statistics, among the three groups in pairwise comparison, the difference was significant, enamel loss in group C significantly increased compared with group A and group B. Before a group of bonded brackets, the brackets were removed and colored in group A. After the removal of the brackets and coloring treatment, the L* value in group B on the tooth surfaces decreased significantly compared with before bonding; compared with the prior to bonding and after debonding, the L* values in group C after coloring treatment increased significantly. Compared with before bonding, after the removal of the brackets, the A* value in group C decreased significantly; after staining, the a* values of the three groups significantly increased. The B* value of group A,B and C significantly increased after shading treatment. After coloring treatment, the △b* value in group B showed significantly positive displacement compared with group A. The SEM showed that the laser assisted debonding caused less damage on the enamel surface after the bracket, which had no obvious color change. Conclusion The effect of the removal of orthodontic brackets and residual agent method with laser assisted is good, which has less impact on the tooth surface, and its operating time conforms to clinical practice, which is not easy to cause tooth restaining, and then, has the value of clinical application.

Key words: orthodontic treatment, laser aided debonding, after the bracket, the tooth surface