| 摘要: | 目的 因牙科用金屬材料長期使用於口腔之溼潤環境下，故本研究欲探討其在液體中之溶出物，對人類口腔上皮細胞之生物親和性與生物效應之影響。方法 將金合金、欽合金、鈀合金、鎳合金及銀粉五種牙科臨床上最常用之材料製作成直徑15mm厚2mm之圓板，經高溫滅菌處理之後，放入內含5mL細胞培養液之塑膠管內於37℃，5% CO2之培養箱內放置24小時，再以其培養液放入內含大約5×10^4個細胞之24孔培養皿中於37℃，5% CO2之條件下培養24小時後，用位相差顯微鏡觀察其形態變化，並進行MTT試驗來測定細胞存率以評估細胞毒性。其中細胞毒性較大之銀粉再利用流式細胞儀來作細胞周J明與細胞凋亡的觀察，並輔以分析培養液中lactate dehydrogenase (LDH)的活性來測試細胞壞死情形，並進一步分析細胞之p53及NF-kB活性，以及利用BrdU-incorporation測其對DNA複製的影響。結果 細胞形態學之觀察及MTr測試顯示4種鑄造用合金未見對細胞有明顯之影響而銀粉則呈現明顯之毒性刺激反應。針對銀粉材料作更進一步的調查顯示銀粉材料未引起細胞凋亡，而LDH測試証明與細胞壞死有關係。P53及NF-kB活性測試顯示經銀粉處理的細胞會產生發炎與逆境反應，BrdU-incorporation測試發現銀粉處理會抑制DNA的複製。結論 根據本次實驗之結果得知使用鑄造合金比銀粉合金更安全。
Purpose. We examinated the cytotoxicity of metallic dental material eluates on human oral epithelium cells and gingival fibroblasts. Methods. A total of five common metallic alloys, including Amalgam, Gold, Nickel, Titanium, and Platinum were tested. Five discs of each alloy were prepared, and each disc was 15 mm diameter and 2 mm thick. After being autoclaved, these alloy discs were incubated with 5 ml of culture medium at 37℃, with 5% CO2 for 24 hours. The medium was then used to grow KB and HGF-1 cells. MTT assay examined the cytotoxicity of alloy eluates after 24-hour incubation. The effects of toxic alloy on cell cycle, necrosis, p53 and NF-kB activity, and DNA synthesis were further examined by flow cytometry, lactate dehydrogenase releasing assay, luciferase assay, and BrdU-incorporation, respectively. Results. Morphologic observation and the MTT test revealed that only the amalgam alloy was cytotoxic. Although flow cytometry showed no apoptotic cells after amalgam alloy treatment, high lactate dehydrogenase activity was found in culture medium. These results suggested that amalgam alloy induced breakdown of the cell membrane, a characteristic of necrosis. In addition, elevated p53 and NF-kB activity after amalgam alloy treatment supported that this alloy could cause inflammatory and stress responses. Finally, BrdU incorporation showed that amalgam alloy inhibited DNA synthesis. Conclusions. Based on the results of this experiment, casting metal alloys are safer than amalgam alloy. |
