ABSTRACT
<p><b>OBJECTIVE</b>To find a way to having higher bond strength on mottled enamel.</p><p><b>METHODS</b>Sixty mottled enamel first bicuspid teeth extracted from fifteen patients needing orthodontic force were prepared and divided into four groups. Group A was routine acid etched, group B was air abraded, group C was etched by clearfil liner self-etching primer, group D was air abraded and then etched by clearfil liner self-etching primer. Next the bond and resin were used. The shear bond strength was observed and compared. The data were analysed by SPSS 11.5 statistical package.</p><p><b>RESULTS</b>The shear bonding strength of group A was (2.247 +/- 0.261) MPa, group B was (5.374 +/- 0.469) MPa, group C was (4.345 +/- 0.401) MPa, group D was (5.791 +/- 0.636) MPa. The strengths of four groups were significantly different (P < 0.01). The adhesive remnant index (ARI) scores of the four groups had no significant difference.</p><p><b>CONCLUSION</b>In clinic, using air abrasion surface preparation technique is an acceptable way to enhancing the shear bond strength before sticking the orthodontic bonding on dental fluorosis.</p>