摘要
目的评估6种正畸加力附件在口内、人工唾液、空气三种环境的剩余力值.方法6种正畸加力附件按材料性能分为组1:金属材质组(镍钛拉簧)和组2:聚氨酯材质组(透明结扎圈、银色结扎圈、分牙圈、弹力线、弹力链).每种材料施加200 g初始拉力,分别置于口内、人工唾液和空气环境中,检测初始状态和加力后4h、1d、2d、4d、7d、14 d、21 d、28 d时间节点的拉力值.结果组1镍钛拉簧在各个时间截点的拉力值均显著大于组2的5种聚氨酯材料.加力4h后6种附件拉力均有显著下降,口内环境剩余力值镍钛拉簧(182.22 g)>弹力线(139.30 g)>弹力链(138.61 g)>透明结扎圈(121.26 g)>分牙圈(109.53 g)>银色结扎圈(100.15 g),人工唾液环境镍钛拉簧(183.22 g)>弹力线(145.14 g)>弹力链(143.55 g)>透明结扎圈(138.14 g)>分牙圈(119.61 g)>银色结扎圈(117.13 g),空气环境镍钛拉簧(196.80 g)>弹力链(160.74 g)>透明结扎圈(157.59 g)>弹力线(153.87 g)>银色结扎圈(147.30 g)>分牙圈(142.08 g).24 h后拉力衰减趋于平缓.同个时间点,5种聚氨酯材质正畸加力附件拉力值均为空气>人工唾液>口内(P<0.05).组1镍钛拉簧在口内和人工唾液环境下力值衰减较空气环境下大(P>0.05).结论正畸加力附件在口腔内存在不同程度的拉力衰减,正畸临床施力需要考虑材料特性和力值衰减规律.
Objective To evaluate the remaining force of 6 orthodontic accessories under three environments:in vivo,in artificial saliva and in dry air.Methods 6 orthodontic accessories were divided into 2 groups:metal material group(NiTi coil springs)and polyurethane materials group(transparent and silver elastomeric ligatures,elastomeric separators,elastomeric threads and elastomeric chains).The orthodontic accessories were stretched with the same initial force(200 g)and were placed in vivo,artificial saliva or dry air condition respectively.The tension values were measured at the initial state and 4h,1 d,2d,4d,7 d,14d,21 d and 28 d after the initial force was applied.Results The force of the metal materials at each time point was significantly greater than that of the five polyurethane materials.After 4h,the tensile forces of 6 orthodontic accessories decreased significantly,and the tensile forces of the accessories in the oral cavity were:NiTi closed coil springs(182.22 g)>elastomeric threads(139.30 g)>>elastomeric chains(138.61 g)>transparent elastomeric ligatures(121.26 g)>elastomeric separators(109.53 g)>>silver elastomeric ligatures(100.15 g),in the atificial saliva were:NiTi closed coil springs(183.22 g)>elastomeric threads(145.14 g)>elastomeric chains(143.55 g)>transparent elastomeric ligatures(138.14 g)>elastomeric separators(119.61 g)>silver elastomeric ligatures(117.13 g),in the dry air were:NiTi closed coil springs(196.80 g)>elastomeric chains(160.74 g)>transparent elastomeric ligatures(157.59 g)>elastomeric threads(153.87 g)?>silver elastomeric ligatures(147.30 g)>elastomeric separators(142.08 g).The tensile force decreased to a relatively stable condition after 24 hours.At the same time point,the tensile forces of 5 polyurethane orthodontic accessories were differnent in three conditions,which was in the air>in artificial saliva>in vivo(P<0.05).The force value of NiTi closed coil springs decreased obviously in vivo and artificial saliva compared with in the dry air condition(P>0.05).Conclusions.There are varying degrees of tension degradation in the orthodontic accessories in the oral cavity.The material properties and the regularity of force degradation should be considered in orthodontic clinical application,
作者
李晓敏
杨柳
冯剑颖
Li Xiaomin;Yang Liu;Feng Jianying(Department of Orthodontics,Zhegiang Chinese Medical University Schoo and Hosprtal of Stomatology,Hangzhou 310053)
出处
《中华口腔正畸学杂志》
2020年第1期35-39,共5页
Chinese Journal of Orthodontics
关键词
力值衰减
加力附件
口内
Force degradation
Orthodontic accessories
In vivo
