Comparison of bond strength between lingual and buccal surfaces on young premolars

The purpose of this experiment was to compare the bond strength and the failure interfaces on lingual and buccal surfaces of young human premolars. Premolar buccal brackets were adapted and bonded on the lingual or buccal surfaces of crowns after etching with a 37% phosphoric acid solution for 15 seconds. The bond strengths were 7.2 MPa and 7.0 MPa for lingual and buccal surfaces, respectively. The bond failure interfaces were located between the bracket and the resin, within the resin itself, or between the resin and the enamel. Tooth fragmentation was not found. There were no statistically significant differences (p > 0.05). This indicates that it is not necessary to specially treat a lingual surface for increasing the bond strength.