2011 Volume 54 Issue 6 Pages 399-405
The purpose of this study was to investigate whether the depth of post holes and the dual-cure selfetching resin bonding system affected root canal dentin. Extracted human central incisors were used in this study. Crowns of the teeth were sectioned at the cement-enamel junction using a low-speed diamond saw. Pulpal tissue was removed by using an endodontic file, and post spaces were prepared by using post drills in a low-speed handpiece to a depth of 5 or 10 mm and diameter of 1.5 mm. The roots were randomly divided into three groups, and their root canal dentin surfaces were treated with one of the following self-etching primers: 1) light-cure system G-bond (GB), 2) dual-cure system trial product (DC), or 3) dual-cure system Unifil Self-etching bond (SE). Post holes were filled with a dual-cure composite resin core material and the fiber posts were then placed in the root canal with finger pressure. Excess resin cement was removed, and cement in the root canal was light-cured. Each root was then cut perpendicular to the long axis, and the resin-dentin interfaces were observed with a scanning electron microscope (SEM) and surface profile measurement microscope. The results of surface analysis by SEM and surface profile measurement microscope revealed gaps in the resin-dentin interface in both specimens of GB. However, no gaps were found at the interface in both specimens of DC and SE. It is suggested that dual-cure bonding systems offer good sealability of build-up restoratives regardless of depth of post hole.
