溶液pH值及氧化鉍對矽酸鈣骨水泥性質之影響

Effect of solution pH and bismuth oxide on the properties of dicalcium silicate cement

江亭儀(Ting-Yi Chiang)

指導教授 ： 丁信智

中山醫學大學/口腔醫學院/口腔科學研究所/博士(2013年)

摘要

白色的三氧礦化聚合物（WMTA）已廣範應用於牙科根管填充治療，然而白色的三氧礦化聚合物還有幾項主要的缺點，如有變色的潛在問題、材料成份中含有有毒性元素、操作困難及較長的硬化時間等缺點。本研究目的是開發新式的矽酸鈣根管填充材，並且對WMTA之物理化學性質進行比較，以改善其臨床應用上的缺點。為此探討 pH 7.4與pH 4.0的模擬體液（simulated body fluid, SBF）及不透光劑-氧化鉍對矽酸鈣骨水泥性質之影響。將添加20 wt%氧化鉍之矽酸鈣骨水泥粉末加入二次水，矽酸鈣骨水泥試片分別放置於不同pH值（pH 7.4和4.0）的SBF中浸泡，並觀察試片浸泡後之表面型態、重量損失、孔隙率、徑向拉伸強度與SBF之pH值變化。此外，為研究不透光劑–氧化鉍對矽酸鈣骨水泥性質之效應，添加不同重量百分比之氧化鉍於矽酸鈣骨水泥中，分析物理化學性質及生物相容性。結果指出矽酸鈣骨水泥試片浸泡於pH 7.4的SBF中1天後，沉積於試片表面之磷灰石球顆粒大於浸泡於pH 4.0的環境中的磷灰石球。然而其徑向拉伸強度並沒有明顯的統計差異（P > 0.05）。試片浸泡於pH 4.0的SBF中30天測量出有0.8%的重量損失；浸泡於pH 7.4的SBF則僅有0.2%的重量增加。另一方面，在氧化鉍含量研究中，發現提高氧化鉍含量顯著（P < 0.05）增加其硬化時間；而對浸泡液之酸鹼值變化和徑向拉伸強度則影響不大。就溶解度而言，不同含量氧化鉍之矽酸鈣骨水泥其溶解度為0.8-1.1%比WMTA的溶解度（1.4%）低，且具統計差異（P < 0.05）。氧化鉍似乎對MG63細胞增生、分化與鈣沉積顯著影響，相較於其他組別，含20 wt%氧化鉍之矽酸鈣骨水泥具較低之細胞增生、分化及礦化量。隨含量的提高降低生物性。本研究總結指出矽酸鈣骨水泥添加10 wt%氧化鉍可使矽酸鈣骨水泥具有良好的硬化時間、不透光性及骨形成性且具有作為取代WMTA用於牙髓根管填充材料之潛力。

關鍵字

關鍵詞：矽酸鈣骨水泥 ； 白色的三氧礦化聚合物 ； 氧化鉍 ； 牙髓根管填充材料。

並列摘要

White-colored mineral trioxide aggregate (WMTA) has been widely used in dental root canal filling treatment. However, there are several drawbacks of WMTA, including the discoloration potential, presence of toxic elements, difficult handling, and long setting time. The purpose of this study was to develop the new calcium silicate endodontic material as an alternative material for the endodontic applications. The effects of different pH (pH 7.4 and 4.0) of simulated body fluid (SBF), and Bismuth Oxide (Bi2O3) on the physicochemical properties of the dicalcium silicate cement were investigated. The morphology, weight loss, porosity, diametral tensile strength, in addition to pH changes in the cement-immersed solutions were evaluated. The physicochemical properties and osteogenicity of calcium silicate cements containing Bi2O3 in varying ratio were also examined. The size of precipitated apatite spherulites on the cement surfaces after soaking in the pH 7.4 solution for 1 day was greater than that in the pH 4.0 solution. Solution pH did not significantly affect (P > 0.05) the diametral tensile strength of cements. After soaking in SBF for 30 days, the sample was associated with a weight loss of 0.8% in the pH 4.0 solution; whereas in the pH 7.4 solution showed a weight increase of 0.2%. A greater porosity of the cement soaked in a pH 4.0 was found compared with that in the pH 7.4 solution. The setting time increased significantly (P < 0.05) with increasing ratio of Bi2O3. The pH value and diametral tensile strength of the cements were slightly affected by introducing Bi2O3. The solubility of the three radiopaque cements ranged between 0.8% and 1.1%, which was significantly (P < 0.05) lower than that of MTA (1.4%). 20 wt% Bi2O3 led to a lower cell proliferation, differentiation and calcium deposits of MG63 on the cement compared with the other cements. It is concluded that the addition of 10 wt% Bi2O3 to calcium silicate cement showed well setting time, radiopacity and osteogenic activity may has a potential for being used a endodotic retro-filling material as an alternative to WMTA.

並列關鍵字

Keywords: Calcium silicate cement ； white-colored mineral trioxide aggregate ； bismuth oxide ； endodotic retro-filling material.

參考文獻

1.Camilleri J. The physical properties of accelerated Portland cement for endodontic use. International Endodontic Journal 2008;41:151–7.

2.Chen CC, Ho CC, Chen CH, Ding SJ. Physicochemical properties of calcium silicate cements for endodontic treatment. Journal of Endodontics 2009a;35:1288–91.

3.Chen CC, Ho CC, Chen CH, Wang WC, Ding SJ. In vitro bioactivity and biocompatibility of dicalcium silicate cements for endodontic use. Journal of Endodontics 2009b;35:1554–7.

4.Chen CC, Wang WC, Ding SJ. In vitro physiochemical properties of gelatin/chitosan oligosaccharide/calcium silicate hybrid cement. Journal of Biomedical Materials Research Part B: Applied Biomaterials 2010;95:456–65.

5.Chen CC, Shie MY, Ding SJ. Human dental pulp cells responses to new calcium silicate-based endodontic materials. International Endodontic Journal 2011;44:836–42.