Reddy Nagam Raja, Abraham Anandapandian Ponsekar, Murugesan Krishnan, Matsa Vasanthakumar
J Indian Prosthodont Soc. 2011 Jun;11(2):106-12. doi: 10.1007/s13191-011-0075-8. Epub 2011 Jun 3.
Recasting of the casting alloys affects the composition and elemental release which may have cytotoxic effect different from the pure alloy in the surrounding tissues. An Invitro study was conducted to investigate the elemental release and their cytotoxic effects from commercially available Ni-Cr dental casting alloys, commonly used for fabricating fixed partial dentures. Three Ni-Cr alloys [Wiron 99(A), Ceramet (B), and Hi Nickel CB (C)] were tested. Alloy specimens (disks 3 × 5 mm) were casted and grouped as follows: Group I (A(1)/B(1)/C(1)): 100% pure alloy; Group II (A(2)/B(2)/C(2)): 50% new with 50% recast; and Group III (A(3)/B(3)/C(3)): 100% recast. Disks of each alloy type from each group were transferred to Dulbecco's modified eagle medium and left for 3 days at 37°C in an atmosphere of 5% CO(2). Ni, Cr, Co, Cu and Mo elemental release from metal alloys into culture medium was investigated using Inductively Coupled Plasma Mass Spectrometry. Cytotoxicity was tested using mouse fibroblast cells and MTT Assay. Controls consisted of 6 wells containing cells with no alloy specimens. Data were analyzed by two-way analysis of variance followed by t-test. The total amount of elements released in parts per billion for various casting groups were Group I, A(1)-6.572, B(1)-6.732, C(1)-8.407; Group II, A(2)-22.046, B(2)-26.450, C(2)-29.189; Group III, A(3)-84.554, B(3)-88.359, C(3)-92.264. More amounts of elements were released in Hi Nickel CB than Ceramet and Wiron 99 in all the three test groups. Percentage of viable cells from MTT analysis were Group I, A(1)-62.342, B(1)-61.322 C(1)-60.593, Group II, A(2)-58.699, B(2)-56.494, C(2)-52.688, Group III, A(3)-53.101, B(3)-52.195, C(3)-47.586. The viable cells present in the culture media were more in Wiron 99 than Ceramet and Hi Nickel CB. Elemental release increased with amount of recast alloy. Amongst the three alloys tested Hi Nickel CB had significantly higher elements released compared to Ceramet and Wiron 99 in 100% pure alloys, 50% recast and 100% recast alloys. Wiron 99 showed least element release in 100% pure alloy, 50% recast and 100% recast specimens. 100% pure alloys of all three alloys are less cytotoxic, but their cytotoxicity is more on 50% and 100% re-casted alloys. Out of all three variations of casting Wiron 99 was least cytotoxic, followed by Ceramet and Hi Nickel CB. Recasting of alloys significantly increased the elements released and their cytotoxicity.
铸造合金的重铸会影响其成分和元素释放，这可能会在周围组织中产生与纯合金不同的细胞毒性作用。进行了一项体外研究，以调查市售用于制作固定局部义齿的镍铬牙科铸造合金的元素释放及其细胞毒性作用。测试了三种镍铬合金[Wiron 99(A)、Ceramet(B)和Hi Nickel CB(C)]。铸造合金试样（3×5毫米的圆盘）并分组如下：第一组(A(1)/B(1)/C(1))：100%纯合金；第二组(A(2)/B(2)/C(2))：50%新合金与50%重铸合金；第三组(A(3)/B(3)/C(3))：100%重铸合金。将每组中每种合金类型的圆盘转移到杜尔贝科改良伊格尔培养基中，在37°C、5%二氧化碳的气氛中放置3天。使用电感耦合等离子体质谱法研究金属合金中镍、铬、钴、铜和钼元素向培养基中的释放。使用小鼠成纤维细胞和MTT法测试细胞毒性。对照组由6个含有细胞但无合金试样的孔组成。数据通过双向方差分析，随后进行t检验进行分析。不同铸造组以十亿分之一计释放的元素总量为：第一组，A(1)-6.572，B(1)-6.732，C(1)-8.407；第二组，A(2)-22.046，B(2)-26.450，C(2)-29.189；第三组，A(3)-84.554，B(3)-88.359，C(3)-92.264。在所有三个测试组中，Hi Nickel CB释放的元素量均多于Ceramet和Wiron 9 在MTT分析中，活细胞百分比为：第一组，A(1)-62.342，B(1)-61.322，C(1)-60.593；第二组，A(2)-58.699，B(2)-56.494，C(2)-52.688；第三组，A(3)-53.101，B(3)-52.195，C(3)-47.586。培养基中存在的活细胞在Wiron 99中比在Ceramet和Hi Nickel CB中更多。元素释放量随重铸合金量的增加而增加。在测试的三种合金中，Hi Nickel CB在100%纯合金、50%重铸合金和100%重铸合金中释放的元素明显高于Ceramet和Wiron 99。Wiron 99在100%纯合金、50%重铸合金和100%重铸试样中释放的元素最少。所有三种合金的100%纯合金细胞毒性较小，但其细胞毒性在50%和100%重铸合金中更大。在所有三种铸造变体中，Wiron 99的细胞毒性最小，其次是Ceramet和Hi Nickel CB。合金的重铸显著增加了元素释放及其细胞毒性。 9。
