An in vitro investigation into the shear bond strengths of two dentine-bonding agents used in the reattachment of incisal edge fragments.

This in vitro study investigated the shear bond strengths of sectioned bovine incisal edge fragments reattached using Gluma 2000 and Scotchbond 2. Teeth were sectioned 3 mm from the incisal edge using an Acutome with a 0.5 mm diamond wheel running at 90 degrees to the mesial or distal surface of the tooth. Twenty four incisal fragments were rebonded with each of the dentine bonding agents; a further 24 intact incisors were used as a control group. The control group required a mean fracture force of 940(+/- 144) N which was significantly greater (p < 0.01) than that required to fracture fragments rebonded using GLUMA 2000 (609 +/- 116) N and Scotchbond 2 (393 +/- 97) N. The mean force required to fracture incisal fragments rebonded with GLUMA 2000 was significantly greater (p < 0.01) than that required to fracture incisal fragments rebonded with Scotchbond 2.