Martin Rebecca L, Monticelli Francesca, Brackett William W, Loushine Robert J, Rockman Roy A, Ferrari Marco, Pashley David H, Tay Franklin R
School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912-1129, USA.
J Endod. 2007 Mar;33(3):272-5. doi: 10.1016/j.joen.2006.11.002. Epub 2007 Jan 4.
One-visit mineral trioxide aggregate (MTA) apexification is gaining in popularity over the use of calcium hydroxide barriers. This study examined the sealing properties of two MTA apexification procedures using an in vitro apexification model. White MTA was introduced into instrumented single-rooted canals with standardized artificially created open apices to form 3- to 5-mm-thick orthograde apical plugs or complete orthograde fillings of the root segments. The remaining canal spaces in the former group were backfilled with thermoplasticized gutta-percha without a sealer. A Flodec fluid filtration device was used to record fluid flow across filled root canals at 48 hours and after 4 weeks of immersion in phosphate-buffered saline (PBS). Although MTA root fillings exhibited a better seal than MTA apical plugs at 48 hours, seals of these two groups were not significantly different after 4 weeks. Interaction of MTA with PBS may result in apatite deposition that improves the seal of MTA apical plugs with time.
与使用氢氧化钙屏障相比，一次性使用矿物三氧化物凝聚体（MTA）进行根尖诱导成形术越来越受到欢迎。本研究使用体外根尖诱导成形模型，检测了两种MTA根尖诱导成形术的封闭性能。将白色MTA引入到已预备的单根根管中，根管具有标准化的人工制备的开放根尖，以形成3至5毫米厚的正向根尖充填物或对根段进行完全正向充填。前一组中剩余的根管空间用热塑牙胶回填，不使用封闭剂。使用Flodec流体过滤装置记录在48小时以及在磷酸盐缓冲盐水（PBS）中浸泡4周后，通过充填后的根管的流体流动情况。尽管在48小时时，MTA根管充填物的封闭性比MTA根尖充填物更好，但4周后这两组的封闭性并无显著差异。MTA与PBS的相互作用可能导致磷灰石沉积，从而随着时间的推移改善MTA根尖充填物的封闭性。
