- 學位論文
以添加乳酸葡萄糖酸鈣之MTA於獵犬牙齒進行直接覆髓影響評估
Evaluation of the dog pulp capping with a novel hydration accelerator of mineral trioxide aggregate
摘要
1993年三氧礦聚合物(Mineral trioxide aggregate, MTA)首次於牙科文獻中出現，MTA擁有許多特性，包括：極佳的封閉性、X光不透性和生物相容性，甚至MTA可以誘導牙本質和牙骨質生成，這些都讓MTA成為極為優秀的牙科材料。目前MTA臨床運用的範圍很廣，包括：活髓治療、覆髓治療、逆充填、穿孔修補和牙根吸收等等。然而在臨床使用上，MTA有許多缺點需要克服：牙齒染色、含有毒性成份、操作性不佳、過長的硬化時間、硬化後移除困難、昂貴的成本…等等。其中操作性不佳，讓MTA操作格外困難；過長的硬化時間，讓MTA易受血水沖刷，進而影響臨床結果。 許多研究針對MTA的性質作改良，添加加速劑可以縮短MTA的硬化時間，然而對於MTA的操作性並沒有顯著改善。根據先前時驗，添加乳酸葡萄糖酸鈣(Calcium Lactate Gluconate, CLG)至MTA中調拌，可以縮短MTA硬化時間外，且可以改善MTA臨床操作性，並且不會影響MTA的生物相容性。 本篇研究的目標就是利用CLG溶液來調拌MTA，以beagle dog牙齒進行直接覆髓之活體動物實驗，來評估其組織及細胞反應。研究假設使用MTA加CLG進行調拌，作為直接覆髓髓的材料，不會造成牙髓發炎反應，並且有dentin bridge的生成。實驗利用10隻beagle dog的4顆前牙，總共40顆牙為樣本。在前牙頰側製備一第五類窩洞，分別置入氫氧化鈣、MTA加水、MTA加CLG進行直接覆髓，接著用玻璃離子體復形起來。經過一和四週後，將牙齒拔除後，進行切片樣本製作，之後結果利用分類系統進行評估。 結果發現，使用氫氧化鈣的組別，可以觀察到牙髓有嚴重的發炎反應，只有少量的硬組織生成。而MTA加CLG這組則與MTA加水有相似的結果，輕微的發炎反應，並可以看到硬組織屏障的生成；而控制組在各項數據都顯示最差。在一週和四週的結果裡，各組間差異具有統計學上的意義；而MTA加水和MTA加CLG在發炎反應上沒有差異，然而在第四週硬組織的生成上有統計學的差異。利用MTA加CLG進行直接覆髓治療，看到了一理想的結果，可以提供臨床上另一種覆髓治療的選項。
並列摘要
In 1993, mineral trioxide aggregate (MTA) was first applied in dentistry, it provides many excellent characteristic, e.g. excellent sealing ability, radiopacity, and biocompatibility. The most important, dentin and cementum formation can be induced by MTA. It’s very excellent property for endodontic application, e.g. vital pulp therapy, pulp capping, retrograde filling, perforation repair, root resorption…etc. In clinical application, MTA has a few drawbacks. The long setting time and poor handling characteristic make clinical use difficult. The setting time of MTA is far longer than other filling materials. Therefore, it’s make MTA easy affected by blood and tissue fluid. Further, the clinical outcome is deeply affected. Addition of accelerators for shortening the initial setting time is a common method. According to our previous study, use Calcium Lactate Gluconate (CLG) instead of sterile water for MTA mixture. The handling property and setting time were improved, makes MTA easy for clinical application. And most important, the addition of CLG for MTA mixture, wouldn’t effected the biocompatibility of MTA. The aim of this study was to evaluation of dog pulp capping with CLG and MTA mixture, to observe the tissue and cell reaction. Our hypothesis is that addition of CLG as accelerator of MTA would induce dentinal bridge formation without pulp inflammation. A class V cavity was prepared in 40 incisor teeth of 10 beagle dogs. Then Ca(OH)2, MTA and MTA with CLG was placed on the exposed pulp. All cavities were restored with glass ionomer. After 1 and 4 weeks, teeth were extracted and processed for histological examination and categorized in histological score system. The result is that Ca(OH)2 group showed severe pulp inflammation and few or absent dentinal bridge formation. In MTA with CLG group showed similar result with MTA with water, mild pulp inflammation and hard tissue barrier formation was observed. Control group showed the worst result in inflammation and hard tissue formation. All groups showed significant difference in inflammation status and hard tissue formation. Further evaluation between MTA with water and MTA with CLG, 4 weeks samples showed the significant difference in hard tissue formation. This direct pulp capping animal study demonstrates that MTA with CLG mixture is biocompatible and can form the dentinal bridge like barrier. CLG instead sterile water for MTA mixture may be an alternative for endodontic clinical use.