Authors : Masoud fallahinejad Ghajari , Roshan Roshennejad and Amir Ghasemi
Abstract: The materials placed between the tooth and its fragment affect treatment of fractured part of the crown. The aim of this controlled in vitro trial study was to compare the microtensile bond strength of three different restorative techniques including composite restoration, fragment reattachment with bonding agent (Excite DSC) and resin cement variolink II. Thirty extracted caries- free human permanent incisors were selected. Each tooth was sectioned buccolingually perpendicular to the long axis at 3 mm from the incisal edge and restored in normal saline. Then samples were divided into three groups randomly, as follow: Fragment reattachment with bonding agent Excite DSC (Ivoclar/ Vivadent), fragment reattachment with resin cement Variolink II (Ivoclar/Vivadent) and restoration with resin composite Tetric Ceram (Ivoclar/Vivadent). After 24 h, the teeth were vertically sectioned into approximately 1 mm� beams for microtensile evaluation, by using Microtensile Tester (Bisco USA). Data were anzlyzed using ANOVA (p=0.05) and tukey,s post hoc. Failure modes were examined by stereomicroscope. The mean value of microtensile bond strength in group 1 (fragment reattachment with bonding agent) was 20.55±2.36Mpa,group 2 (fragment attachment with resin cement) 34.64±2.99 Mpa and group 3 (composite restoration) 38.23±1.95 Mpa. The ANOVA analysis showed significant differences microtensile bond strength values in three groups (p< 0.001). The dominant failure mode was mixed in all groups. Composite restored teeth show higher MTBS compared with the reattached ones. Using Variolink II for fragment reattachment has higher bond strength than Excite DSC.
Masoud fallahinejad Ghajari , Roshan Roshennejad and Amir Ghasemi , 2007. Microtensile Bond Strength of Fragment Reattachment Vs. Resin Composite Restoration in Crown Fractures . Research Journal of Biological Sciences, 2: 682-686.