A comparison of shear bond strengths between new and recycled ceramic brackets

The recycling of 'used' ceramic brackets in the orthodontic surgery has been previously described. The present study investigated the shear bond strength of both recycled and new ceramic brackets. The mean shear bond strengths of the new and recycled ceramic brackets were 259.7 +/- 88.2 N and 187.2 +/- 60.8 N, respectively. Although significantly lower (P less than 0.01), the bond strength of recycled ceramic brackets appeared to be clinically adequate. There appeared to be little difference in the variation in bond strength between the new and recycled ceramic bracket group. Our results showed that the site of bond failure depended on the magnitude of bond strength. Scanning electron micrograph examination of the failure sites showed enamel fracture in one sample where the bond strength was extremely high.