不同残根处理术式对斜折残根抗折力的影响  

Effect of different root treatment techniques on fracture resistance of oblique residual root

作　　者：王晓雪[1] 吴素然 张立亚 焦薇薇 沈文静[1] 仇亚非[1] WANG Xiaoxue;WUSuran;ZHANG Liya;JIAO Weiwei;SHEN Wenjing;QIU Yafei(Department of Prosthodontics,Hebei Key Laboratory of Stomatology,Hebei Clinical Research Center for Oral Diseases School and Hospital of Stomatology,Hebei Medical University,Shijiazhuang 050017)

机构地区：[1]河北医科大学口腔医学院·口腔医院,河北省口腔医学重点实验室,河北省口腔疾病临床医学研究中心,石家庄050017

出　　处：《现代口腔医学杂志》2025年第1期26-30,共5页Journal of Modern Stomatology

基　　金：河北省卫生健康委员会医学科学研究课题计划项目(20221471)。

摘　　要：目的研究改良式牙冠延长术、常规牙冠延长术和正畸牵引术对纤维桩核冠修复后下颌前磨牙斜折残根抗折强度和断裂模式的影响。方法选取32颗下颌第一前磨牙(均为单根管),常规根管治疗后,于舌侧釉牙骨质界上3.0 mm处截冠,自舌侧斜向颊侧釉牙骨质界上1 mm处进行切割,制成舌颊向斜折残根模型,将其随机分为4组(A-D组),每组8颗。A组设为对照组,设计成舌侧2.0 mm、颊侧0 mm高的半包绕型牙本质肩领;B组模拟改良式牙冠延长术,设计成2.0 mm高的全包绕型牙本质肩领;C组和D组分别模拟常规式牙冠延长术和正畸牵引术,设计成舌侧4.0 mm、颊侧2.0 mm高的全包绕型牙本质肩领。经预成玻璃纤维桩加树脂核及钴铬金属全冠修复后,自凝树脂块包埋试件。包埋完成的试件置于万能试验机上加载(加载方向与牙长轴成150°)直至断裂。记录试件折裂载荷及折裂模式,并进行统计学分析。结果A、B、C、D各组试件的折裂载荷均值依次为(1.45±0.10)、(1.67±0.09)、(0.78±0.24)、(1.87±0.09)kN,三种不同残根处理术式对纤维桩核冠修复后斜折残根抗力影响差异有统计学意义(P<0.05),与对照组相比,模拟正畸牵引术组和模拟改良式牙冠延长术组的抗折强度均显著增大,模拟常规冠延长术组的抗折强度显著减小。结论龈下残根保留治疗的优先选择方案为正畸牵引术与改良式牙冠延长术,同时,需合理设计冠根比值(小于1),以确保修复后残根的抗力。Objective To investigate the impact of including modified crown lengthening,conventional crown lengthening,and orthodontic traction on the flexural strength and fracture pattern of mandibular premolars following fiber post-core crown restoration.Methods Thirty-two mandibular first premolar teeth with single canals were selected for the study.After undergoing conventional root canal treatment,the crowns were sectioned at 3.0 mm above the lingual enamel cementum boundary and then further cut at 1mm above both lingual and buccal enamel cementum boundaries to create lingual and buccal oblique broken residual root models.The models were randomly divided into four groups,each containing eight teeth.Group A served as the control group with a half-wrapped dentine shoulder collar designed to be 2.0 mm high on the lingual side and 0 mm high on the buccal side.Group B simulated improved crown lengthening by featuring a full-wrapped dentin shoulder collar that was 2.0 mm high;Group C and D simulated conventional crown lengthening and orthodontic traction,respectively,with fully wrapped dentine shoulder collars measuring 4.0 mm in height on the lingual side and 2.0 mm in height on the buccal side.Following repair with preformed glass fiber posts,resin cores,and cobalt chromium metal crowns,specimens were embedded in self-coagulated resin blocks before being subjected to loading using a universal testing machine(loading direction set at an angle of 150°with respect to tooth long axis)until failure occurred.Fracture load values along with fracture modes of each specimen were recorded for subsequent statistical analysis.Results The average fracture load of each group A,B,C and D was(1.45±0.10),(1.67±0.09),(0.78±0.24)and(1.87±0.09)kN,respectively.There was statistical significance in the effect of three different stump treatment methods on the resistance of oblique broken stump after fiber post and core crown restoration(P<0.05).Compared with the control group,the flexural strength of the simulated orthodontic traction group

关 键 词：改良式牙冠延长术 常规牙冠延长术 正畸牵引术 斜折残根 抗折性能 

分 类 号：R783.3[医药卫生—口腔医学]