磷酸三鈣及羥基磷灰石基底之光固化複合覆髓材料之改良

Abstract

因材料蓬勃發展，活髓治療(Vital pulp therapy)成為牙髓暴露的另一治療選項，且有一定的成功率。市售常見的材料都有相當多的文獻證明其物理化學性質穩定、具有生物相容性等優點，但仍有些缺點待改善。三氧礦化聚合物(Mineral trioxide aggregate, MTA)有固化時間過長、不易操作的缺點。牙本質生物活性修補材料(Biodentine)凝固時間有改善但仍需等待一段時間。“畢氏”光固化矽酸鈣襯底材(TheraCal LC)有較快的固化時間，但研究指出其細胞毒性不建議作為活髓治療材料。本研究團隊於兩年前研製光聚合活髓材料B5，細胞毒性低，材料誘導牙髓細胞礦化程度和Biodentine相同且固化時間快等優點，但仍有機械強度不足的缺點。本實驗目的以不同比例之光照聚合樹脂與填料混和後，與同為光聚合之活髓市售材料TheraCal LC做比較，並比較不同比例填料的差異。 本實驗採用表面改質材料-油酸以及羥基磷灰石取代B5去離子水增加硬度，並測試光聚合固化溫度上升變化量，改善材料性質後，材料之生物相容性以細胞活性測試、材料對於細胞分化的影響則以細胞礦化實驗測試，並以聚合酶連鎖反應觀察材料對於細胞分化、礦化之基因影響。本實驗分為兩組，一組以樹脂取代去離子水(R和OA)。R和OA的差別為OA添加2%油酸。另一組以不同比例的25µm HA取代去離子水且都添加2%油酸(分別為OAHA20，OAHA25，OAHA27.5，OAHA30)。 實驗結果發現活髓材料OAHA25硬度相較於B5顯著增加，且固化前後溫度上升量較市售活髓材料TheraCal LC少。細胞活性較TheraCal LC佳，細胞毒性小，且和TheraCal LC同樣能誘導細胞產生礦化現象。

With the vigorous development of dental materials, vital pulp therapy(VPT) has become a treatment option for pulp exposure that has achieved considerable success. Numerous studies on commercial products have been conducted to prove the stable physical and chemical properties and biocompatibility of these products. However, some shortcomings remain that must be addressed. Mineral trioxide aggregates have the disadvantages of a long solidification time and difficult handling. The setting time for Biodentine has been shortened, but a long waiting time is still required. TheraCal LC has a fast setting time, but many studies have not recommended it for use as a vital pulp therapy capping material due to its high cytotoxicity. Two years ago, our team developed a light-cured vital pulp capping material called “B5.” B5 has the advantages of low cytotoxicity, a degree of mineralization that matches Biodentine, and a fast curing time. Insufficient mechanical strength is B5’s lone disadvantage. The purpose of this study is to compare different ratios of light-cured vital pulp therapy materials with TheraCal LC and to compare the different ratios of fillers of capping materials. Surface modification materials, namely, oleic acid and Hydroxyapatite (HA), were used in B5 to replace deionized water and thereby improve hardness. We measured the degree of temperature increase and cell viability and conducted mineralization of gene and real-time PCR tests. This experiment was divided into two groups, one group replaced deionized water with resin (R and OA), and the difference between R and OA is that 2% oleic acid is added to OA. The other group replaced deionized water with different ratios of 25 µm HA and all added with 2% oleic acid (OAHA20, OAHA25, OAHA27.5, OAHA30, respectively). Results showed that the hardness of the vital pulp therapy material OAHA25 increased significantly, and the increase in temperature in OAHA25 was less than that of TheraCal LC. The cytotoxicity of OAHA25 was also less than that of TheraCal LC. Finally, OAHA25 was shown to induce mineralization of dental pulp stem cells in a manner similar to that of TheraCal LC.