Sittichoke Osiri. Resistance to fracture and bond strength to root dentin of roots filled with bioceramics using a matched cone technique. Master's Degree(Dentistry). Mahidol University. Mahidol University Library and Knowledge Center. : Mahidol University, 2018.
Resistance to fracture and bond strength to root dentin of roots filled with bioceramics using a matched cone technique
Abstract:
Obturation root canals with bioceramics might improve fracture resistance of roots due to a possibility of proper adhesion, sealer penetration, and modulus of elasticity (MOE). The objective of this study was to evaluate root reinforcement of bioceramic cone/sealer (BCC/BCS)- by investigating root fracture resistance, push-out bond strength, sealer penetration, and MOE in comparison to gutta-percha/AH Plus (GP/AH). Seventy-four roots from bilateral mandibular premolars were conservatively prepared using Ni-Ti rotary files. For root fracture resistance, forty roots were randomly divided into 4 groups (n = 10 each): intact roots, prepared (non-obturated) roots, and the roots obturated with either BCC/BCS or GP/AH. All root canals were obturated with matched single cone technique, and then loaded with a spreader-like tip until fracture. For push-out bond strength (n = 10 each), coronal, middle and apical root slices obturated with BCC/BCS and GP/AH were loaded with a cylindrical plunger, and failure modes were determined. Sealer penetration into root canal dentin of BCC/BCS and GP/AH (n = 12 each) were evaluated for maximum depth, circumferential and total penetration area at coronal, middle, and apical levels using confocal laser scanning microscopy. MOE was investigated according to ISO 4049:2000. Loads to fracture of BCC/BCS, GP/AH and intact roots were not significantly different, but these were significantly higher than the prepared, non-obturated roots. BCC/BCS provided higher bond strength, maximum depth, and circumferential penetration at apical root level, and greater sealer penetration area at all levels than GP/AH. MOE of all materials were much lower than dentin. BCC/BCS and GP/AH reinforced the conservatively prepared roots due to bondability, which the fracture strengths were similar to intact roots.