唐婉容，李丽华，米方林，吴艳，刘英

(川北医学院口腔系，四川 南充　637000)



Nobilium钴铬钼合金铸造卡环固位力的研究

唐婉容，李丽华，米方林，吴艳，刘英

(川北医学院口腔系，四川 南充637000)

目的：比较钴铬钼合金和纯钛铸造卡环在反复脱位循环过程中固位力的变化趋势，为Nobilium整铸支架义齿的卡环设计提供理论参考。 方法：制作下颌第二前磨牙的标准金属基牙，用失蜡法铸造RPT卡环试件36个，钴铬钼合金卡环组和纯钛卡环组各18个，每种金属试件又根据倒凹深度的不同平均分为3个小组，分别为0.25 mm组、0.5 mm组、0.75 mm组(每个小组各6个试件)，对卡环进行摘戴循环实验，使用Chatillon 测力仪测定其在0、1 200、2 400、3 600、4 800、6 000、7 200次循环周期时的固位力值。结果：(1)0.5 mm倒凹时，Nobilium钴铬钼合金T卡固位力大于纯钛卡环，差异有统计学意义(P=0.017 5)，0.25 mm、0.75 mm倒凹时，Nobilium固位力大于纯钛，差异无统计学意义(P>0.05)；(2)分别比较纯钛或钴铬钼合金卡环在3种倒凹深度下的固位力，无显著性差异(P>0.05)；(3)Nobilium卡环在循环结束后的固位力大于循环初始。结论：Nobilium钴铬钼合金铸造T型卡环具有良好的固位力，且有较强的抵抗永久形变的能力，可以在摘戴过程中保持有效的固位力，0.5 mm为其适宜的倒凹深度。

Nobilium钴铬钼合金；铸造卡环；固位力

【Abstract】Objective：To compare the trend of the retention change during the circulation of the clasp dislodging and inserting between Cobalt-Chromium-Molybdenum alloy and pure titanium casting clasps,it can provide theoretical reference for the design of clasps in Nobilium casting framework dentures.Methods：Fabricating standard metal abutment of the second mandibular premolar,and then 36 RPT clasps was cast from Cobalt-Chromium-Molybdenum alloy (n=18)and pure titanium(n=18)with lost-wax casting craft.Each group was subdivided in three parts,corresponding to 0.25 mm,0.50 mm and 0.75 mm undercuts,respectively,and every part contains 6 clasps.The specimens were subjected to an insertion/removal circulation test.The chatillon force measuring instrument was used to record the retention force at different circulation times(0,1 200,2 400,3 600,4 800,6 000,7 000 times).Results：(1)Under the 0.50 mm undercut,the retention force of Nobilium Co-Cr-Mo alloy T clasps is better than the pure titanium clasps,the difference has statistical significance (P=0.017 5).In the other conditions,although Co-Cr-Mo consistently showed greater rentention compared to pure titanium,no significant differences were observed (P>0.05).(2)Comparing retention force for the three undercuts between the pure titanium and Co-Cr-Mo,no statistically significant differences(P>0.05).(3)Analyzing the Co-Cr-Mo alloy during the test,it had a slight increase in retention force from the beginning to the end of the simulation test.Conclusion：Nobilium Cobalt-Chromium-Molybdenum alloy casting T clasps have good retention force and greater ability to resist permanent deformation,and can keep effective retention force during the circulation of the clasp dislodging and inserting.The best undercut depth is 0.5 mm.

【Key words】Nobilium 2000；Casting clasps；Retention force

牙列缺损是指上颌或下颌的牙列内有数目不等的牙缺失，同时仍余留不同数目的天然牙，是口腔患者的常见疾病[1]。可摘局部义齿(removable partial denture，RPD)是临床修复牙列缺损最常用的方法之一，具有适用范围广，磨除牙体组织少，制作方法简便。患者可以自行摘戴，便于清洁，便于修理等优点。随着我国……