Ex vivo shear bond strength of fibreglass reinforced aesthetic brackets

Fibreglass reinforced brackets (FGBs) and ceramic brackets were bonded to the enamel of extracted premolars to evaluate their shear bond strength and fracture mode. One-hundred extracted premolars were divided into five groups, and combinations of two-paste and no-mix composite, and plastic bracket conditioner were used in the test groups. Bond strength testing was carried out 24 hours after direct bonding. The shear strength of ceramic brackets with a two-paste composite was significantly higher than FGBs bonded with either two-mix or no-mix composite ( P < 0.05). Ceramic brackets bonded with two-mix and no-mix composite demonstrated a 30 and a 10 percent enamel fracture rate, respectively. There were no enamel or bracket fractures in any of the FGB groups.