14牙周－牙髓联合病变Periodontal-EndodonticCombinedLesions14-1牙周组织和牙髓的解剖通道AnatomicalInterrelationsofPeridontiumandPulp根尖孔Apicalforamen根管侧支Lateralrootcanal或副根管Accessorycanal根尖1/3处最多根分叉区20-60%有Thepulpwasnon-vitalandthetoothwasendodonticallytreated.AfterprosthetictherapyThepulpwasnon-vitalandthetoothwasendodonticallytreated.Afterprosthetictherapy(c),the2-yearfollow-upradiographin(d)showsbonefillinthepreviousangularbonydefect,whereasthemarginalboneremainsatthesamelevel.Oncarefulexaminationonecanseethatalateralcanalcommunicatingwiththelateralbonedefectwasfilled.牙本质小管Dentinaltubules解剖异常Anatomicalabnormalities腭侧沟牙根外吸收根裂14-2牙周-牙髓联合病变的临床类型ClinicalPatternsofPeriodontal-EndodonticCombinedLesions1，根尖感染经牙周组织途径排除，有人称之为逆行性牙周炎(retrogradeperiodontitis)牙髓根尖周病对牙周组织的影响influenceofendodonticlesionsontheperiodontium根尖脓肿沿牙周的可能排脓途径Schematicillustrationdemonstratingpossiblepathwaysfordrainageofaperiapicalabscessintothegingivalsulcus/pocket.(a)periodontalligamentfistulation.(b)extraosseousfistulationperiodontalligamentfistulation.此型在临床上易被误诊为牙周脓肿特点：死髓牙窄而深的牙周袋，无明显的牙槽嵴吸收onlyanarrowopeningofthefistulaintothegingivalsulcus/pocketandmaynotbedetectedunlesscarefulprobingofthesulcusiscarriedoutatmultiplesites.邻牙一般无严重的牙周炎X片显示烧杯型或日晕型病变after18MInmultirootedteethaperiodontalligamentfistulationcandrainoffintothefurcationarea２，牙髓治疗过程中或治疗后造成的牙周病变根管侧穿，髓室底穿，髓室或根管内的药物（砷戊二醛塑化液干髓剂等）Duringendodontictreatment,andinconjunctionwithpreparationofrootcanalsfortheinsertionofposts,instrumentationcanaccidentallycauseperforationoftherootandwoundingoftheperiodontalligamentAngularbonedefectatthedistalrootsurfaceofamandibularpremolar(arrows).Therootisperforated.Conceivably,thisoccurredinconjunctionwithpreparationoftherootcanalforapostandcore.Clinicalsymptomsincludeddrainageofpusfromthepocketandincreasedtoothmobility.Thetoothwasextracted.Perforationofthepulpalfloorofthemandibularfirstmolaroccurredinconjunctionwithasearchforrootcanalopenings(a).Theperforationwasimmediatelysealedwithgutta-percha(b).Onemonthaftertreatmentaslightradiolucencyappearedattheperforationsite(arrow)intheperiodontium(c).Afteranobservationperiodof2years,normalperiodontalconditionswerere-establishedbothclinicallyandradiographicallyRCT治疗后可发生牙根纵裂:主要由于扩根过度,桩核不当,过大合力等共同特点:牙髓无活力病变局限于单个牙，局限于患牙的局部病变呈烧杯状，邻牙基本正常Verticalrootfracture结局:Verticalrootfracturesthatinvolvethegingivalsulcus/pocketareausuallyhaveahopelessprognosisduetocontinuousbacterialinvasionofthefracturespacefromtheoralenvironment.ExternalRootresorptionSurfaceresorptionAsurfaceresorptionisinitiatedsubsequenttoinjuryofthecementoblasticcelllayer.OsteoclastsareattractedbysubstancesfromthedamagedtissueonthedenudedrootsurfaceandresorbthehardtissueTheseresorptionsmaybecausedbyalocalizedinjuryinconjunctionwithexternaltrauma(Andreasen1981)andbytraumafromocclusion.Resorptionmayalsoresultfromexcessiveorthodonticforces.Thistypeofresorptioniscommon,self-limitingandreversibleReplacementresorptionThistypeofresorptiveprocessresultsinareplacementofthedentalhardtissuesbybone,hencethenameReplacementresorptionandankylosisareoftenusedassynonyms.Clinically,ankylosisisdiagnosedbyabsenttoothmobilityandbyapercussiontonethatishigherthaninanormaltoothExternalinflammatoryresorptionThetermexternalinflammatoryresorptionsuggeststhepresenceofaninflammatorylesionintheperiodontaltissuesadjacenttoaresorptiveprocess14-3治疗原则Treatmentstrategiesforvombinedendodonticandperiodontallesions确定原发原因。联合病变的预后往往取决于牙周病损的预后，牙周破坏不严重，牙齿不松动，预后较好1，由牙髓根尖病变引起的牙周病变清除感染源的牙髓－消除袋内感染－完善RCTFirstobservetheresultofthistherapyandinstituteperiodontaltherapylaterifnecessary2，逆行性牙髓炎主要看患牙能否保留牙髓初步治疗，如病变可以控制，牙髓－牙周同时治疗
