SlideShare verwendet Cookies, um die Funktionalität und Leistungsfähigkeit der Webseite zu verbessern und Ihnen relevante Werbung bereitzustellen. Wenn Sie diese Webseite weiter besuchen, erklären Sie sich mit der Verwendung von Cookies auf dieser Seite einverstanden. Lesen Sie bitte unsere Nutzervereinbarung und die Datenschutzrichtlinie.
SlideShare verwendet Cookies, um die Funktionalität und Leistungsfähigkeit der Webseite zu verbessern und Ihnen relevante Werbung bereitzustellen. Wenn Sie diese Webseite weiter besuchen, erklären Sie sich mit der Verwendung von Cookies auf dieser Seite einverstanden. Lesen Sie bitte unsere unsere Datenschutzrichtlinie und die Nutzervereinbarung.
Introdution• In different studies success rate ranges from 54 percent to 95 percent.• The definition of success is ambiguous - stringent : radiographic and clinical normalcy - lenient : only clinical normalcy
Endodontic treatment outcome• Healed: both clinical and radiographic presentations are normal• Healing: it’s a dynamic process, reduced radiolucency combined with normal clinical presentation• Disease: No change or increase in radiolucency, clinical signs may or may not be present or vice versa
Evaluation of success• Success or failures following endodontic therapy could be evaluated from combination of clinical, histopathological and radio graphical criteria.
Clinical evaluation for success• No tenderness to percussion or palpation• Normal tooth mobility• No evidence of subjective discomfort• Tooth having normal form, function and aesthetics• No sign of infection or swelling• No sinus tract or integrated periodontal disease• Minimal to no scarring or discoloration
Radiographic evaluation for success• Normal or slightly thickened periodontal ligament space• Reduction or elimination of previous rarefaction• No evidence of resorption• Normal lamina dura• A dense three dimensional obturation of canal space
Histological evaluation for success• Absence of inflammation• Regeneration of periodontal ligament fibers• Presence of osseous repair• Repair of cementum• Absence of resorption• Repair of previously resorbed areas
Causes of the endodontic failures Bacteria somewhere in the root canal system Divided into local and systemic
Factors affecting success orfailure of endodontic therapy in every case• Diagnosis and the treatment planning• Radiographic interpretation• Anatomy of the tooth and root canal system• Debridement of the root canal space
Factors affecting success orfailure of endodontic therapy in every case• Quality and extent of apical seal• Quality of post endodontic restoration• Systemic health of the patient• Skill of the operator
Factors affecting success or failure of a particular case Factors affecting success or failure of a particular case• Pupal and Periodontal status• Size of periapical radioleucency• Canal anatomy• Crown and root fracture
Factors affecting success or failure of a particular case Factors affecting success or failure of a particular case• Iatrogenic errors• Extent and quality of the obturation• Quality of the post endodontic restoration• Time of post treatment evaluation
Local Factors causing endodontic failures• Infection• Incomplete debridement of the root canal system• Excessive hemorrhage• Chemical irritants• Iatrogenic errors
Infection• infected and necrotic pulp tissue→main irritant to the periapical tissues• The host parasite relationship 、 virulence of microorganisms , ability of infected tissues to heal→influence the repair of the periapical tissues• Endo success →debridement
Incomplete debridement of the root canal system• Main objective of root canal therapy→complete elimination of the microorganisms and their byproducts• Poor debridement → residual microorganisms 、 byproducts and tissue debris → recolonize
Excessive hemorrhage• Extirpation of pulp and instrumentation beyond periapical tissues• Local accumulation of the blood→mild inflammation• Extravasated blood cells and fluid ： foreign body nidus for bacterial growth
Over instrumentation• Instrumentation beyond apical foramen→PDL and alveolar bone trauma→the prognosis of endodontic treatment ↓
Chemical irritants• Intracanal medicaments and irrigating solution →extruded in the periapical tissues→the prognosis of endodontic treatment ↓• One should take care while Using medicaments to avoid their periapical extrusion
Iatrogenic errors• Separated instruments—• Caused by improper or overuse of• instruments and forcing them in curved canals• Prognosis ： no much affected in vital pulps poor in necrotic tissue.
Iatrogenic errors• Canal blockage and ledge formation—• Accumulation of dentin chips or tissue debris prevent the instruments to reach its full working length• Ledge formation—straight instruments in curved canals• These lead to bacteria & debris remained endo failure
Iatrogenic errors• Perforations—• Lack of knowledge of anatomy of the tooth, attention, misdirection of the instruments• Prognosis ： location, time, perforation seal and size• Poor prognosis remaining infected tissue
Iatrogenic errors• Incompletely filled teeth—• Teeth filled more than 2mm short of apex• Several studies shown ：• poor prognosis—underfillings with necrotic pulps• Overfilling of root canals—• Overfilling extending ≧ 2mm beyond• radiographic apex• Continuous irritation of the periapical• tissues endo failure
Iatrogenic errors• Anatomic factors—• Such as ： overly curved canals, calcifications,• numerous lateral and accessory canals,• bifurcations, C or S shaped canals• Problems in cleaning and shaping &• incomplete filling of root canals• endodontic failure
Iatrogenic errors• Root fractures—• Partial or complete fractures of roots• Prognosis of teeth ：• vertical root is poor than horizontal fractures• Traumatic occlusion –• Cause endo failures because of its effect on• periodontium
Endodontic retreatment Before going/performing Case selection Prognosis ,Contraindications and problems Steps
Before going to endodontic retreatment• when should Treatment be considered• Patient’s needs• Strategic importance of the tooth• Periodontal evaluation of the tooth• Chair time & cost
Before performing to endodontic retreatment• May to prevent the potential disease• Remove/remade extensive coronal restoration• Technical problems• May not achieve better results• Filling materials have to be removed• Prognosis could be poorer• Patient might be more apprehensive
Case selection• Careful history• Anatomy of root canal , canal curvature, calcifications,unusual configurations• Quality of obturation• Iatrogenic complications• Cooperation of the patient
Factors affecting prognosis of endodontic treatment• Periapical radiolucency• Quality of the obturation• Apical extension of the obturation material• Bacterial status• Observation period• Postendodontic coronal restoration• Iatrogenic complication
Contraindications of endodontic retreatment• Unfavorable root anatomy• Untreatable root resorptions or perforations• Root or bifurcation caries• Insufficient crown/root ratio
Problems of endodontic retreatment• Unpredictable result• Frustration• Cost factor• Time consuming
Steps of Retreatment1. Coronal disassembly2. Establish access to root canal system3. Remove canal obstructions4. Establish patency5. Thorough cleaning, shaping and obturation of the canal
1. Coronal Disassembly• Removal of existing • Access made through coronal restoration coronal restoration
Disadvantages ofAdvantages of gaining retaining aaccess through restoration:original restoration: a. Reduce visibility anda. Facilitate rubber dam accessibility placement b. Increased risks ofb. Maintaining form, irreparable errors function and aesthetics c. Increased risks ofc. Reducing the microbial infection if cost of replacement crown margins are poorly adapted
Advice:Remove the existing restorationEspecially: poor marginal adaptation, secondary cariesPlace temporary crown to maintain form, function and aesthetics.
2. Establish Access to Root Canal SystemTeeth restored with post andcore:1.Post and core need to beremoved for gaining access toroot canal system2.Post and core can be perforatedto gain access
Posts can be removed by:1. Weakening retention of posts by use of ultrasonic vibration.2. Forceful pulling of posts but it increases the risk of root fracture3. Removing posts with the help of special pliers using post removal systems
Siver point removalC- Using Hedstroem files(H-files)
Silver Point RemovalE- Post removal system kit.D- Instrument removal system(IRS).
Gutta-Percha Removal• The relative difficulty in removing gutta-percha is influenced by some factors of canal system: Length Diameter Curvature Internal configuration• Progressive Manner : gutta-percha is best removed from canal in progressive manner to prevent its extrusion periapically
Gutta-Percha Removal• Coronal portion of gutta-percha should always be explored by Gates-Gliddens to: Quickly : Remove gutta-percha quickly Solvent : Provide space for solvents Convenience : Improve convenience form• Gutta-percha can be removed by using: Solvents Hand instruments Rotary instruments Microdebrider
1. Solvents• GP is soluble in: Chloroform ： most effective but carcinogenic with high concentratin , excessive filling in pulp chamber is avoided Methyl chloroform Benzene Xylene Eucalyptol oil Halothane• GP dissolution should be supplemented by using hand instruments
2. Hand Instruments Used mainly in apical portion of the canal.• Hedstroem files• Hot endodontic instrument like Reamer or files Poorly condenced GP can be pulled easily
3. Rotary Instruments•They are Safe to be used in straight canals Recently:•ProTaper universal systems Consisting of file :D1 D2 D3 500-700 rpm
Protaper universal system• D1 : Remove filling from the coronal third• D2 : Remove filling from the middle third• D3 : Remove filling from appical third
Microdebriders A small files with 90 degrees bends Removing remaining gutta-percha on the sides of canal walls
Pastes and Cement Soft setting pastes Penetrated by endodontic instruments Hard setting cements Softened by solvents: xylene, eucalyptol...... Then removed by files . Ultrasonic devices
Separated Instruments and Foreign Objects Coronal third – attempt retrieval Middle third – attempt retrieval or bypass Apical third – surgical treat
Instrument removal system (IRS) Can be used to remove the broken files microtube screw wedge
The beveled end of the microtube The introduction of the screw wedge which isoriented toward the outer wall of the rotated CCW to engage and displace the headcanal to “scoop up” the head of the of the file out the side window.broken file.
Completion of the Retreatment Thorough cleaning, shaping and obturation The outcome of retreatment Short-term: no pain and swelling Long-term: depended regaining canal patency & obturation of the root canal system Retreatment is mostly associated with procedural complication. Effective communication is required b/t dentist & patient.