University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, 18071, Granada, Spain.
University of La Havana, Biomaterials Department, San Lázaro y L. Municipio Plaza de la Revolución, La Havana, Cuba.
J Dent. 2019 Sep;88:103162. doi: 10.1016/j.jdent.2019.06.009. Epub 2019 Jul 5.
To evaluate the effectiveness of different endodontic canal sealers for dentin permeability reduction and to determine the viscoelastic performance of root dentin after their application.
Cervical, medial and apical root dentin surfaces were treated with two experimental hydroxyapatite-based cements, containing sodium hydroxide (calcypatite) or zinc oxide (oxipatite); an epoxy resin- based canal sealer, AH Plus; and gutta-percha. Root dentin was evaluated for fluid filtration. Field emission scanning electron microscopy, energy dispersive analysis, AFM, Young's modulus and Nano-DMA analysis were also performed, at the inner and outer zones of dentin.
Dentin treated with oxipatite showed the lowest microleakage among groups with hermetically sealed tubules and zinc-based salt formations. Samples treated with oxipatite showed the highest Ei at the cervical dentin third among groups, at 6 m of storage. Oxipatite promoted the highest complex modulus and tan delta values at the inner zone of both cervical and medial root dentin. Calcypatite favored the lowest tan delta outcomes at the inner zone of apical dentin at 6 m.
Specimens treated with oxipatite showed the highest sealing ability, based on the highest Young's modulus and dentin mineralization, achieved by closing dentinal tubules, voids and pores that reinforced the inner zone of root dentin. The homogeneity of viscoelastic properties among the different root dentin thirds favored the energy dissipation without creating zones of stress concentration and micro-cracking which would have challenge micropermeability. Thereby, among the tested materials oxipatite is proposed as canal filling material and sealer in endodontics.
Oxipatite could be considered a good candidate for root canal filling material and sealer due to its improved long-term sealing ability and to the advanced remineralization, and so to the enhanced energy dissipation achieved at the inner zone of the radicular dentin.
评估不同根管封闭剂降低牙本质渗透性的效果，并确定应用后根管牙本质的黏弹性性能。
用两种基于羟基磷灰石的实验性水泥（含氢氧化钠的钙磷灰石或氧化锌的氧化磷灰石）、一种基于环氧树脂的根管封闭剂 AH Plus 和牙胶处理颈、中、根尖牙本质表面。评估牙本质的流体过滤情况。还对内、外牙本质区进行场发射扫描电子显微镜、能量色散分析、原子力显微镜、杨氏模量和纳米 DMA 分析。
在密封的小管和锌基盐形成方面，氧化磷灰石处理的牙本质显示出最低的微渗漏。在储存 6 个月时，在颈牙本质第三区，氧化磷灰石处理组的 Ei 值最高。氧化磷灰石促进了内区颈和中牙本质的最高复合模量和 tan delta 值。在储存 6 个月时，钙磷灰石有利于根尖牙本质内区的 tan delta 值最低。
氧化磷灰石处理组表现出最高的密封能力，其基于最高的杨氏模量和牙本质矿化，通过封闭牙本质小管、空隙和孔隙来实现，从而增强了根管牙本质的内区。不同根管牙本质第三区之间的黏弹性性能均匀性有利于能量耗散，而不会产生应力集中和微裂纹区，这将挑战微渗透性。因此，在测试的材料中，氧化磷灰石被提议作为根管填充材料和密封剂在牙髓学中使用。
氧化磷灰石由于其改善的长期密封能力以及先进的再矿化，因此在内区根管牙本质中实现了增强的能量耗散，因此可以被认为是一种良好的根管填充材料和密封剂候选物。
