Adhesive remnant index 'ARI' revisited. An in vitro assessment of clinically debonded orthodontic brackets

Background. In orthodontics, bond failure at the enamel surface can cause enamel fractures and occurs when the bond between bracket and adhesive is excessively strong.; Purpose. Using the indirect ARI score, the associations between location of bond failure and tooth type, arch type, bracket type, enamel preparation method, clinical debonding technique, archwire and gender were evaluated.; Methods. Using a light microscope at x10 magnification the principal investigator (ARS) evaluated the residual cement left adhering to the bracket bases following; (1) spontaneous debonding during treatment, or (2) debonding by different clinicians using different techniques at completion of treatment.; Results. Tooth group and clinician had a significant influence on location of bond failure (p<0.0001). Spontaneously debonded brackets failed mainly at the enamel-adhesive interface.; Conclusions. (1) More cement is left adhering to anterior teeth compared with posterior teeth; (2) The individual clinician rather than the debonding technique has the potential to damage tooth material.