模拟正畸牵引术联合牙本质肩领设计对斜折残根抗折力影响的实验研究  

Effect of different ferrule lengths on the fracture resistance of endodontically treated mandibular premolars restored with prefabricated fiber post-and-core system after simulated orthodontic forced eruption method

作　　者：孟庆飞 张甲第 孟箭 

机构地区：[1]东南大学医学院附属徐州医院口腔科,徐州221009

出　　处：《现代口腔医学杂志》2018年第1期32-35,共4页Journal of Modern Stomatology

基　　金：徐州市医学青年后备人才(徐卫科教[2015]7号);江苏省青年医学人才(QNRC2016391)

摘　　要：目的通过模拟正畸牵引术在斜折残根颈部预备不同高度的牙本质肩领,比较研究牙本质肩领高度对斜折残根抗折力的影响。方法 24颗完整离体下颌第一前磨牙于舌侧釉牙骨质界(CEJ)上2.0mm处水平型截冠,自水平型残根颈部断面的舌侧向颊侧斜形切割,制备舌唇向斜折残根模型。所有残根随机分为3组,F0组残根在根颈部预备颊侧0.0mm、舌侧2.0mm高的180°半包绕肩领(对照组),OE/F1组和OE/F2组通过模拟正畸牵引术在残根颈部分别预备颊侧1.0mm、2.0mm高的肩领,对应舌侧肩领高度分别为3.0mm和4.0mm。经预成玻璃纤维桩核、铸造金属全冠修复后,所有试件自铸造全冠颈缘完成线根方2.0 mm包埋于自凝塑料块中。将试件以与牙长轴成135°于万能试验机上加载,直至试件发生折裂。记录试件断裂载荷并进行统计学分析(α=0.05)。结果三组试件的断裂载荷均值(kN)依次为:1.01±0.26、0.96±0.25、0.76±0.20。"牙本质肩领"对纤维桩核冠修复后斜折残根抗力影响无显著性差异(F=2.402,P=0.115)。颊侧无肩领对照组的残根抗力最高,而通过模拟正畸牵引术在斜折残根颊侧预备2.0 mm肩领时,预成纤维桩核全冠修复牙齿的抗折强度最低;结论通过模拟正畸牵引术在下颌第一前磨牙舌唇向斜折残根颈部预备1.0~2.0mm全包绕牙本质肩领,会降低残根的抗折力;且肩领的高度越高,残根的抗折力越低。Objective The purpose of this study was to evaluate the effect of ferrule design on the fracture resistance of endodontically treated mandibular first premolars after simulated orthodontic forced eruption methods restored with a fiber post-and-core system. Methods Twenty-four extracted and endodontically treated mandibular first premolars were decoronated to create lingual to buccal residual oblique root models, with a 2.0 mm height of the lingual dentine wall coronal to the cemento-enamel junction, and the height of buccal surface at the cemento-enamel junction.The roots were divided randomly into three equal groups. The control group had undergone incomplete ferrule preparation in the cervical root, with 0.0 mm buccal and 2.0 mm lingual ferrule lengths（Group F0）. Simulated orthodontic forced eruption provided ferrule preparations of 1.0 mm（Group OE/F1）and 2.0 mm（Group OE/F2）on the buccal surface and ferrule lengths of 3.0 mm and 4.0 mm on the lingual surfaces, respectively. After restoration with a glass fiber post-and-core system and a cast Co-Cr alloy crown, each specimen was embedded in an acrylic resin block to a height on the root2.0 mm from the apical surface of the crown margin and loaded to fracture at a 135° angle to its long axis in a universal testing machine. Data were analyzed statistically using one-way ANOVA with Tukey HSD tests and Fisher＇s test, with α=0.05. Results Mean fracture loads（kN） for groups F0, OE/F1 and OE/F2 were as follows： 1.01（S.D. =0.26）, 0.96（0.25）and 0.76（0.20）, respectively. One-way ANOVA revealed no significant differences for the effect of ferrule lengths（P=0.115）but no differences for the effect of cervical treatment methods（P〉0.05）. The teeth with no buccal ferrule preparation in Group F0 had the highest fracture resistance. In contrast, the mean fracture loads for group OE/F2 with a2.0 mm buccal and a 4.0 mm lingual ferrule created by simulated orthodontic forced eruption method were lowest.Conclusion For lingual-to-buccal obli

关 键 词：牙本质肩领 正畸牵引术 纤维桩核 斜折残根 抗力 

分 类 号：R781.2[医药卫生—口腔医学]