A review on Success and Failure in endodontic treatment

A review on Success and Failure in endodontic treatmentPoints from ingle5 year study conducted by the University of Washington-patients recalled at 6 months, 1,2,5 years.Success/failure evaluated mainly by radiographic assessment at recall time.Success-teeth that demonstrated decided periradicular improvement and those with continuing periradicular health.Failure those teeth that initially demonstrated periradicular damage and that had not improved, as well as those that had deteriorated since treatment.Results at 2 year recall were discussed-total 3678 patients, 1229 at 2 year recall104 failures reported.

Failure in Washington study:13 causes, subdivided into 3 groups:Apical percolationOperative errorErrors in case selectionApical percolation 63.46%Incomplete obturationUnfilled canalAg point inadvertently removedOperative error 14.42%Root perforationCanal grossly overfilled or overextendedBroken instrument

Errors in case selection 22.12%External root resorptionCoexistent periodontal-periradicular lesionDeveloping apical cystAdjacent pulpless toothAccessory canal overfilledConstant traumaPerforation, nasal floorDistribution of Failures of Treated Endodontic Cases: Two-Year Recall by Frequency of Occurrence

Causes of failureNo of failures% failuresIncomplete obturation 6158.66Root perforation 109.61External root resorption 87.7Coexistent periodontal-periradicular lesion6 5.78Canal grossly overfilled or overextended43.85Canal left unfilled 32.88Developing apical cyst 32.88Adjacent pulpless tooth 32.88Silver pointinadvertently removed21.92Broken instrument 10.96Accessory canal unfilled 10.96Constant trauma 10.96Perforation, nasal floor 10.96Total failures 104When arranged by frequency of occurrence, note that incomplete obturation accounts for almost 60% of all failures, followed by root perforation, which accounts for nearly 10% of 104 failures. Cause of failure includes infrequently encountered conditions that occur less than 1% of the time.

5Prognosis:1. The more extensive and severe the endodontic pathosis, the poorer the prognosis. 2. The more dental treatment that is done, the poorer the prognosis. The worst prognosis lies with teeth that have been retreated nonsurgically and then re-treated surgically once or twice more.Grossman divided the causes into four categories: poor diagnosis, poor prognosis, technical difficulties, and careless treatment.POOR PAST, (Crump et al DCNA 1979)Perforation, Obturation, Overfill,Root canal missedPeriodontal disease, another tooth, split,Trauma," all of which may cause endodontic failure.Postoperative causes of failurePost space preparation and placementInadequate restorationOcclusal trauma and bruxismSuperimposed nonendodontic causes- orthodontic treatment and periodontal pathologyOthers Post space preparation and placementPerforation improper orientationDisturbance of remaining obturated materialInadequate thickness of obturating material leftLateral forces on dentine during post placement- especially tapered, threaded posts.Tapered posts create a wedging effect.Post width exceeding 1/3rd of the canal width.Absence of ferrule can predispose the crown to fractureDelay in post cementation leading to leakage due to a leaking interim post and artificial crown.

Improper coronal restorationTime period between obturation and permanent restoration is long.Temporary restoration is left for a long time.Inadequate thickness of temporary restoration minimum 3.5mm.Lack of marginal seal of leading to secondary cariesTooth is non-vital any progressing caries does not cause symptoms and generally remains undetected until clinical examination.Margin of the restoration impinging on the biological width improper cleaning, periodontal pocketing, secondary caries, lack of marginal integrity.

Occlusal trauma and bruxismCrown/tooth fracture due to overloading- as abutment for precision attachments, distal extension base RPDs, posterior cantilevered fpd.Inadequate coronal restorationIn cases of bruxism, full coverage restorations are essential(Abou Rass)Night bruxism intensifies normal pressure 10 times because proprioception is lost in REM sleep.Superimposed nonendodontic causesOrthodontic treatmentPeriodontal problemsOther factorsLack of proximal contactsSystemic diseasespreventionLong-term followupCases of unresolving post-treatment periapical radiolucencies are commonly referred to as 'endodontic failures'. It is generally acknowledged that most failures occur when treatment procedures have not reached a satisfactory standard for the control and elimination of infection. Common problems that may lead to endodontic failure include inadequate aseptic control, poor access cavity design, missed canals, inadequate instrumentation, and leaking temporary or permanent fillings (Sundqvist and Figdor, 1998).referencesAn Evaluation of Coronal Microleakage in Endodontically Treated Teeth. Part I. Time Periods JOE vol 13 no2 Shigeyuki S, Masahiko I, Hiroshi K, et al. Analysis of bruxism occlusal force concerning formation of facet on occlusal splint for estimation of bruxism. Japanese Journal of Conservative Dentistry. 2006;49(1):6-16.Restoration of Endodontically Treated Teeth Paul R. Chalifoux, DDS