ONLINE ONLY Shear and tensile bond strength comparison of various contemporary orthodontic adhesive systems: An in-vitro study Claudia A. Reicheneder, a Tomas Gedrange, b Alexandra Lange, c Uwe Baumert, d and Peter Proff e Regensburg and Greifswald, Germany Introduction: The purpose of this study was to compare the shear and tensile bond strengths of 8 common adhesive systems for bonding in orthodontics. Methods: One hundred sixty freshly extracted bovine mandib- ular permanent incisors were randomly divided into 8 groups. Self-ligating esthetic Damon 3 brackets (Ormco, Orange, Calif) were bonded by using the following adhesive systems: Quick Bond (chemically and light-cured; Forestadent, Pforzheim, Germany), Blugloo (Ormco), Enlight LV (Ormco), Kurasper F (Kuraray Dental, Frank- furt, Germany), Transbond LR (3M Unitek, Monrovia, Calif), Light Bond (Reliance Orthodontic Products, Itasca, Ill), and Fuji Ortho LC (GC America, Alsip, Ill). After 24 hours, half of each group was debonded measuring the shear bond strength and half measuring the tensile bond strength. Results: Blugloo showed the best shear bond strength values, whereas Transbond LR and Quick Bond (chemically and light-cured) had the lowest. Tensile strength was the highest with Fuji Ortho LC and the lowest with Quick Bond (chemically and light- cured) and Kurasper F. The tensile strength of light-cured Quick Bond was about 47% lower than that of Fuji Ortho LC. Conclusions: Blugloo, Fuji Ortho LC, Light Bond, and Enlight LV are among the materials of choice for bonding fixed orthodontic appliances to teeth. All bond strength values were clinically satisfactory except for the tensile strength of chemically and light-cured Quick Bond and Kurasper F. (Am J Orthod Dentofacial Orthop 2009;135:422.e1–422.e6) D irect bonding, first described by Newman in 1965, 1 was a major improvement in daily ortho- dontic practice. Bond failures of brackets can sig- nificantly increase chair-side time, treatment time, and efficiency. Therefore, much effort has been put into im- proving the quality of the adhesive systems for direct bonding. Bond strength can be influenced by various fac- tors such as light-curing devices, type of enamel condi- tioner, acid concentration, etching time, composition of the adhesive, bracket base design, and bracket material. 2-4 The most commonly used adhesive systems are light-cured or chemically cured composite resins, usu- ally combined with acid-etching. Mostly, sufficient bond strength of composite resins was found, but unde- sirable effects such as loss of enamel during acid-etch- ing 5 and enamel decalcification around the brackets 6 have been reported. Recently, the adhesive Blugloo (Ormco, Orange, Calif) was developed; it not only possesses the property of color change with temperature but, according to the manufacturer, also has much greater bond strength when used with the esthetic Damon 3 bracket (Ormco). As an alternative, bracket adhesive glass ionomer ce- ment (GIC) was introduced by Wilson and Kent 7 in 1972. GIC was shown to have lower bond strengths than com- posite resins, 8 but had the positive effect of releasing fluoride. 9 In addition, it does not require acid etching and can be bonded to a moist enamel surface. 10,11 GIC, a hybrid of silicate and polycarboxylate cements, was improved by adding resin particles to its formulation, re- sulting in the current resin-modified GIC (RMGIC). 12 These adhesives release fluoride like conventional GIC and can be successfully used to bond orthodontic brackets because of their relatively high bond strengths. 13-15 Itoh et al 16 found that RMGICs have greater bond strengths with etched enamel, and Bishara et al 17 found that, with etched enamel and wet conditions, a Senior instructor, Department of Orthodontics, Regensburg University Medi- cal Center, Regensburg, Germany. b Associate professor and chair, Department of Orthodontics, Preventive and Pe- diatric Dentistry, Medical Center, Ernst-Moritz-Arndt-University of Greifswald, Greifswald, Germany. c Postgraduate student, Department of Orthodontics, Preventive and Pediatric Dentistry, Medical Center, Ernst-Moritz-Arndt-University of Greifswald, Greifswald, Germany. d Statistician, Department of Orthodontics, Regensburg University Medical Center, Regensburg, Germany. e Associate professor and chair, Department of Orthodontics, Regensburg Uni- versity Medical Center, Regensburg, Germany. The authors report no commercial, proprietary, or financial interest in the prod- ucts or companies described in this article. Reprint requests to: Claudia A. Reicheneder, Department of Orthodontics, Regensburg University Medical Center, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany; e-mail, claudia.reicheneder@gmx.net. Submitted, March 2008; revised and accepted, July 2008. 0889-5406/$36.00 Copyright Ó 2009 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2008.07.013 422.e1