不同方法预备根管对根管治疗后牙齿冠渗漏影响［摘要］目的采用3种不同方法预备根管，评价其对根管治疗后牙齿冠渗漏的影响。方法48颗单根管离体牙随机分为4组，使用不同的根管预备方法去除根管壁的玷污层。A组为对照组，采用生理盐水和过氧化氢溶液冲洗根管；B组采用乙二胺四乙酸(EDTA)凝胶和5.25%次氯酸钠溶液冲洗;C组采用Odontoson-M型超声波治疗仪荡洗；D组采用脉冲Nd：YAG激光照射。每组取2颗牙，于扫描电子显微镜(SEM)下观察冠部玷污层的去除情况；其余10颗牙采用ObturaII高温注射式热牙胶垂直加压法充填根管，氧化锌丁香油黏固剂封闭根管口，浸于质量浓度20g-L-1亚甲基蓝溶液中染色7d,脱水脱钙制作透明牙标本，体视显微镜下测量染料渗入的深度。结果SEM观察：A组整个根管内壁被覆玷污层及大量碎屑，牙本质小管被堵塞；B组与C组根管内壁清洁,玷污层消失，牙本质小管开放；D组根管内壁牙本质小管封闭或半封闭，玷污层熔融消失。A、B、C、D组染料渗入深度分别为(2.15±0.38)、(1・75±0.28)、(2.04±0・40)、(1.73±0.36)mmoA组的渗入深度明显高于B、D组，其差异有统计学意义(P<0.05)o结论使用不同的方法预备根管去除玷污层，可以减少根管治疗后牙齿的冠渗漏。［关键词］玷污层；超声波；冠渗漏；Nd：YAG激光;根管治疗［中图分类号］R781.05［文献标志码］A［doi］10.3969/j.issn.1000-1182.2012.05.017Effectofdifferenttechniquesinrootcanalpreparationoncoronalmicroleaka.geofendodonticallytreatedteethLiuYan,MaWeidong,GaoWeihong・(Dept.ofSpecialDiagnosis,DalianStomatologicalHospital,Dalian116021,China)［Abstract］ObjectiveTocomparetheeffectofthreetechniquesinrootcanalpreparationoncoronalmicrolea-kageofendodonticallytreatedteeth・MethodsForty-eighthumansingle-rootedteethweredividedinto4groupsrandomlyandsubjectedtodifferenttechniquesonremovalofsmearlayer.GroupA,thecontrolgroup,irrigationwithhydrogenperoxide(H202)andnormalsaline(NS)；groupB,smearclearedwith5.25%sodiumhypochlorite(NaClO)andethylenediaminetetraacetis(EDTA)gel；groupC,irrigationwithOdontoson—Multrasonics；groupD,smearlayerremovedwithNd：YAGlaserirradiation.Twospecimensofeverygroupweresplitlongitudinallyintoequalsegmentsandcanalwallsatcoronalportionwereexaminedunderscanningelectronmicroscope(SEM)・ThententeethofeverygroupwerefilledwithwarmverticalcondensationbyObturaIIthermoplasticizedgutta-perchinjectiontechniqueandsealedwithzincoxideeugenol(ZOE).Theteethwereimmersedin20g•L-lmethylenebluefor7days,thenweredemineralized,dehydratedandcleared.Lineardyepenetrationwasdeterminedunderasteremicroscope・Thedatawerestatisticallyanalyzed・ResuItsIngroupA,thereweresmearlayeranddebrisremainedanddentinaltubuleswerecovered・IngroupBandgroupC,thesmearlayerofrootcanalswereremovedanddentinaltubuleswereopen.IngroupD,therootcanaldentinaltubulesweresealedorsemi-sealedandthesmearlayerweremeltedandablated・ThemeanlengthofcoronalmicroleakageforgroupA,B,C,Dwere(2.15±0.38),(1.75±0.28),(2.04±0.40),(1.73±0.36)mm.TheanalysisshowedthatthelinearingroupAwaslongerthanthatingroupBandgroupDclearly(P<0.05).ConclusionThecoronalmicroleakagefollowingrootcanaltreatmentcouldbereducedbyremovingsmearlayerwithdifferenttechniquesinrootcanalpreparation.
