Calcium silicate cement-induced remineralisation of totally demineralised dentine in comparison with glass ionomer cement: tetracycline labelling and two-photon fluorescence microscopy
Calcium silicate cement-induced remineralisation of totally demineralised dentine in comparison with glass ionomer cement: tetracycline labelling and two-photon fluorescence microscopy
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DOI：
10.1111/jmi.12197
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发表时间：
2015-02-01
影响因子：
2
通讯作者：
Watson, T. F.
中科院分区：
文献类型：
--
作者：
Atmeh, A. R.;Chong, E. Z.;Watson, T. F.
采用双光子荧光显微镜结合四环素标记观察硅酸钙基修复材料（Biodentine（TM））和玻璃离子水门汀（GIC：FujiIX）对完全脱矿牙本质的再矿化潜力。将40个脱矿牙本质盘与三种不同溶液中的任一种粘固剂一起储存：含四环素的磷酸盐缓冲盐水（PBS）、无磷酸盐四环素和无四环素PBS。脱矿牙本质的另外的样品单独储存在第一溶液中。在37 ℃下储存8周后，使用双光子荧光显微镜和拉曼光谱对牙本质样品进行成像。随后将样品嵌入PMMA中，并在SEM中通过20 kV BSE成像研究抛光块表面，以研究矿物质浓度的变化。在PBS/四环素溶液中与Biodentine（TM）一起储存的牙本质显示出最高的荧光强度。这些样品还显示出基质矿化的微观特征，包括矿化前沿以及管内和管间矿化。在其他溶液中，牙本质表现出弱得多的荧光，这些特征都检测不到。拉曼光谱证实了磷酸钙矿物的形成，其拉曼峰类似于磷灰石，而在无水泥或无PBS介质或GIC中储存的牙本质中未检测到矿物形成。因此，可以得出结论，Biodentine（TM）在富含磷酸盐的介质中储存时，可诱导牙本质基质中磷酸钙矿物质的形成，而四环素标记可选择性地检测到这一点。Lay描述牙本质脱矿是龋齿的最早阶段，导致牙本质等牙齿组织中的矿物质流失。对于龋齿的管理，受损和脱矿物质的牙本质通常由牙医切割并在放置适当的修复材料之前去除。这个过程可能是广泛的，留下最少的牙本质来支持修复，这可能会影响修复牙齿的耐久性和功能。最近，采用了更保守的方法，建议保留脱矿的牙本质，并鼓励矿物质沉积回到其有机基质中（矿化）。硅酸钙粘固剂，称为波特兰粘固剂，已用于牙科应用超过二十年，但没有太多证据表明其能够诱导脱矿牙本质的再矿化。虽然不同的技术已被应用于评估牙本质矿化，但其检测矿化的能力仅限于表面表征，无法对有机基质结构内的矿化过程进行高分辨率观察。双光子荧光显微镜是一种亚表面成像技术，可以对深层组织进行高分辨率成像。将该技术与荧光矿化标记染料（例如四环素）相结合，可以提供改进的矿化成像技术。本研究使用四环素标记的双光子荧光显微镜评价了基于硅酸钙的牙科修复材料（Biodentine（TM））诱导完全脱矿牙本质再矿化的潜力。
Two-photon fluorescence microscopy, in combination with tetracycline labelling, was used to observe the remineralising potentials of a calcium silicate-based restorative material (Biodentine(TM)) and a glass ionomer cement (GIC:FujiIX) on totally demineralised dentine. Forty demineralised dentine discs were stored with either cement in three different solutions: phosphate buffered saline (PBS) with tetracycline, phosphate-free tetracycline, and tetracycline-free PBS. Additional samples of demineralised dentine were stored alone in the first solution. After 8-week storage at 37 degrees C, dentine samples were imaged using two-photon fluorescence microscopy and Raman spectroscopy. Samples were later embedded in PMMA and polished block surfaces studied by 20 kV BSE imaging in an SEM to study variations in mineral concentration. The highest fluorescence intensity was exhibited by the dentine stored with Biodentine(TM) in the PBS/tetracycline solution. These samples also showed microscopic features of matrix remineralisation including a mineralisation front and intra- and intertubular mineralisation. In the other solutions, dentine exhibited much weaker fluorescence with none of these features detectable. Raman spectra confirmed the formation of calcium phosphate mineral with Raman peaks similar to apatite, while no mineral formation was detected in the dentine stored in cement-free or PBS-free media, or with GIC. It could therefore be concluded that Biodentine(TM) induced calcium phosphate mineral formation within the dentine matrix when stored in phosphate-rich media, which was selectively detectable using the tetracycline labelling.Lay Description Dentine demineralisation is the earliest stage of dental caries that cause mineral loss from the dental tissues such as dentine. For the management of dental caries, damaged and demineralised dentine is usually cut by the dentist and removed before placing an appropriate restorative material. This procedure could be extensive leaving minimal dentine to support the restoration, which may affect the durability and functionality of the restored tooth. Recently, more conservative approaches have been adopted that suggest leaving the demineralised dentine and encouraging the deposition of minerals back into its organic matrix (remineralisation). Calcium silicate cements, known as Portland cement, has been used for dental applications for more than two decades, but not much evidence exists on their ability to induce the remineralisation of demineralised dentine. Although different technique has been applied to evaluate dentine remineralisation, their ability to detect mineralisation is limited to surface characterisation, which does not enable high resolution observation of the mineralisation process within the structure of the organic matrix. The two-photon fluorescence microscopy is a subsurface imaging technique that allows imaging of deep tissues with high resolution. Combining this technique with a fluorescent mineralisation labelling dye, such as tetracycline, could provide an improved mineralisation imaging technique. This study evaluated the potential of calcium-silicate based dental restorative material (Biodentine(TM)) to induce remineralisation of totally demineralised dentine using two-photon fluorescence microscopy with tetracycline labelling.