Bond Strength of Orthodontic Adhesives

The objective of this study was to evaluate and compare bond strength of four adhesives used in orthodontics for bonding brackets to tooth enamel. The adhesives used in this investigation were resin-reinforced glass-ionomer cement (Fuji Ortho LC-GC Corporation, Japan), light cured composite resin adhesives (ConTec LC-Dentaurum, Germany and Enlight Bonding system-Ormco, USA) and dual cured composite resin adhesive (ConTec Duo -Dentaurum,Germany). A sample of 80 extracted human premolars was divided into four groups of 20 teeth which were etched with 37% phosphoric acid and bonded in dry field to enamel of buccal and lingual surfaces of the teeth with the same adhesive in one group. The debonding force was produced using universal Instron testing machine with cross head speed of 1mm/min and shear bond strength was measured. Statistical analysis used in this study included: Kolmogorov-Smirnov test i Shapiro-Wilk test, Mann Whitney test, Kruskal Wallis chi-squared test. Even though, all four adhesives showed sufficient bond strength for orthodontic bonding, ConTec LC and ConTec Duo displayed the superior bonding properties comparing to Enlight and Fuji Ortho LC.