局部增粗铸造桩对斜折单根牙固位力和抗折力的影响  

Effects on retention force and fracture resistance of single root tooth with diagonal fracture by the local enlargement of casting post

作　　者：余科 郑立舸 刘敏 

机构地区：[1]四川医科大学附属口腔医院修复科,四川泸州646000

出　　处：《口腔医学》2015年第10期810-812,共3页Stomatology

基　　金：四川省卫生厅科研课题(100250)

摘　　要：目的探讨局部增粗的铸造桩对斜折单根牙固位力和抗折力的影响。方法收集新鲜拔除下颌第一前磨牙105颗,从牙冠颊侧釉牙骨质界冠方2 mm、舌侧釉牙骨质界根方2 mm截去牙冠,根管治疗后备用。取60颗牙随机分为4组,3组实验组分别在制作铸造桩时在桩的尖端增粗0.1 mm、0.2 mm和0.3 mm,对照组常规制作铸造桩。将桩加粘结剂敲击就位于对应的离体牙中,体视显微镜观察离体牙有无折裂,然后对无折裂离体牙进行拉力实验。取45颗牙分为3组,分别制作桩尖端增粗0.1 mm铸造桩、常规铸造桩和纤维桩,进行抗折实验。结果桩尖不增粗和增粗0.1 mm组无牙折裂,增粗0.2 mm和0.3 mm组均有牙折裂;桩尖不增粗组与增粗0.1 mm组的固位力有统计学差异(P=0.000),而抗折强度无统计学差异(P=0.134);两铸造桩组与纤维桩组抗折强度均有统计学差异(P=0.000)。结论铸造桩尖部增粗0.1 mm能增强斜折单根牙固位力,不增加牙折几率。Objective To explore the influence on retention force and fracture resistance of single root tooth with diagonal fracture when casting post was locally enlarged. Methods 105 mandibular first premolars newly extracted were gathered,with the decoronation from 2 mm above buccal cemento-enamel junction（ CEJ） to 2 mm under lingual CEJ prepared for the root canal therapy. 60 teeth were randomly assigned to 4 groups. In three experiment groups,the tips of casting posts were enlarged by 0. 1 mm,0. 2 mm,0. 3 mm respectively; in the control group,the posts were made by convention. Then all these posts were knocked into the corresponding teeth with luting agent,fractures of the teeth were observed with stereomicroscope,and the tensile tests were made to those teeth with no fractures.The remaining 45 teeth were assigned to 3 groups,and conventional casting posts,casting posts with 0. 1 mm enlarged tip,and fiber posts were made respectively for fracture resistance tests. Then breaking-resistant tests were done. Results No fracture was found in the control group and the 0. 1 mm enlarged group,while in the 0. 2 mm,0. 3 mm enlarged groups,dental fractures were observed. There was statistical difference concerning retention force（ P = 0. 000）,but no difference concerning fracture resistance（ P = 0. 134） between the control group and the 0. 1 mm enlarged group. There was statistical difference concerning fracture resistance between the two casting posts groups and the fiber posts group（ P = 0. 000）. Conclusions The retention force of single root tooth with diagonal fracture can be enhanced with the casting posts when the tips were enlarged by 0. 1 mm,with no risk of dental fracture.

关 键 词：铸造桩 增粗 固位力 抗折力 

分 类 号：R783.3[医药卫生—口腔医学]