I. Objective
Mineral trioxide aggregate(MTA) has been widely used in perforation repair, retrofillin, pulp capping and apexification. Recently, MTA as orthograde canal filling has been tried. However, few studies have performed to investigate the sealing ability of MTA as routine filling material. Therefore, the purpose of this study was to evaluate the sealing ability of MTA as a root canal filling material compared with gutta percha.
II. Materials & Methods
18 extracted human mandibular molars were collected. The canals were instrumented with Profile system(Dentsply Maillefer, Ballaigues, Switzerland) to a master apical size of #35 in a crown down manner and obturated with gutta percha (Obtura III Max System, Obtura Spartan, Fenton, MI, USA) and AH plus sealer (Dentsply DeTrey, Konstanz, Germany) or ProRoot MTA(Dentsply, Tulsa Dental, Tulsa, OK) using a specialized MTA delivery gun, Micro-Apical Placement (MAP) System(Dentsply, Tulsa Dental Specialties, Tulsa, OK). All canal filling procedures were performed under a dental microscope(OPMI PICO; Carl Zeiss, Gottingen, Germany) at 10x magnification. Micro-Computed Tomography(Skyscan 1076, SkyScan, Konitch, Belgium) was used to measure a gap between a tooth surface and a root filling material. Then NRecon(NRecon v1.6.3.2; Skyscan) and CTAn( SkyScan) was used for reconstruction and measurement of the space of the gap. Mann-Whitney test were used to determine the statistical differences of mean median between 1) a gap space
of MTA and GP groups 2) a gap space of mesial canal and distal canal groups.
III. Results
Then the percentage space(SG%) of the gap between tooth structure and the root filling material was calculated as following formula: SG% = SG/(SG+SM). Median of MTA group and GP group were 6.1194 and 1.2631. Median of Mesial group and Distal group were 0.5786 and 3.2097. There was a statistically significant difference of mean median between MTA and GP group, Distal group and Mesial group. For MTA and GP each gorup, a significant difference investigated of mean median of Mesial canal and Distal canal group also.
IV. Conclusion
Obvious advantages of the micro-CT method are is fast speed, reproducibility and conservation of the specimens. Mandibular molar was selected because of their anatomy, presence of isthmus in mesial canal and moderate apical curvature. Based on the results of this study from the micro-CT analysis, Sealing ability of MTA is not better than GP.
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