Effects of 3 adhesion promoters on the shear bond strength of orthodontic brackets: An in-vitro study

Introduction: The objectives of this study were to (1) determine the effect of 3 adhesion promoters on shear bond strength and the amount of remnant adhesive on the teeth after debonding and (2) learn whether 1 promoter is material-specific, as stated by the manufacturer. Methods: The promoters tested were OrthoSolo (Ormco, Orange, Calif), All-Bond 2 (Bisco, Schaumburg, Ill), and Enhance L.C. (Reliance, Itasca, Ill). Two adhesives were used: Transbond XT (3M Unitek, Monrovia, Calif) and Light Bond (Reliance). One hundred fifty premolars were divided into 6 groups of 25, and brackets were bonded according to the manufacturers' instructions: (1) Transbond XT, (2) Transbond XT plus All-Bond 2, (3) Transbond XT plus OrthoSolo, (4) Transbond XT plus Enhance L.C., (5) Light Bond, and (6) Light Bond plus Enhance L.C. Bond strength was tested on a universal testing machine, and remnant adhesive was quantified with image analysis equipment. Results: The highest bond strength values were obtained when brackets were bonded with Light Bond plus Enhance L.C. These values were significantly higher than those achieved with Transbond XT, Transbond XT plus Enhance L.C., or Transbond XT plus All-Bond 2. Of the groups bonded with Transbond XT, the group that included OrthoSolo had the best results. Conclusions: None of the adhesion promoters significantly increased bond strength or the amount of adhesive remaining on the tooth after debonding. Enhance L.C. produced the greatest bond strength when used with the material-specific product Light Bond.