BDS11143 Non-Surgical Retreatment PDF

Retreatment ?? AAE A procedure to remove root canal filling materials from the tooth followed by cleaning, shaping, and obturating the canals. Endodontic retreatment is a procedure that is performed on a tooth that previously has had attempted definitive treatment and now requires further treatment...

Retreatment ?? AAE A procedure to remove root canal filling materials from the tooth followed by cleaning, shaping, and obturating the canals. Endodontic retreatment is a procedure that is performed on a tooth that previously has had attempted definitive treatment and now requires further treatment to ensure a successful result. The rationale for nonsurgical retreatment is to remove the content of root canal space as a source of irritation to the attachment apparatus. It is a procedure aim to remove materials from root canal space (if Present), address deficiencies or repair defects that are either pathologic or iatrogenic. oCavity design defects. oUntreated canals ( Major – Accessory ) oPoorly cleaned and obturated oComplications of instrumentation. oOver extension of root filling materials. oCoronal leakage. microbial Non-microbial Intra-radicular Extra-radicular microorganism infection Foreign body reaction True cyst o This is due to: o Inadequate cleaning & shaping of the Root Canal System o Failure of entombing the bacteria with proper three dimensional obturation. o Improper coronal seal. o The most common bacterium is Enterococcus Faecalis & fungus infection with Candida Albicans. This is due to: Extrusion of infected dentin chips Contamination with overextended instruments Periodontal pocket The host response may destroy these bacteria although some types of bacteria can evade the host response as Actinomyces Israelii & Propioni bacterium propionicum. Several materials can produce this condition as, Cellulose fibers from paper points Overextended GP & Sealers. So failure goes with leakage around the over extended filling & bacterial contamination Types a. True cyst with epithelial lining & lumen b. Pocket cyst , open lumen with the root canal Incidence 15%- 42% of all periapical lesions after non surgical endodontic treatment usually require enucleation. clinical radiographic histological Do nothing Non surgical Retreatment Surgical Retreatment Extract the tooth 1- Need for retreatment 2- Patients preferences 3- Strategic importance of the tooth 4- Restorability of the tooth 5- Periodontal condition of the tooth 6- Time and Cost 7- Referral 1- crown disassembly (Coronal Access) 2- gaining access to apical area post removal Removal of restorative materials 3- removal of root filling material Silver Point removal Gutta percha removal Carrier-based Gutta percha removal Paste removal 4- Managing mishaps Ledges Canal blockage Broken instruments perforations Improperly constructed restoration Properly restoration but need for extra access Intact properly constructed restoration Cementing agent Resotoration types Restoration design Preparation type Systemtype Ultrasonic Laser radiation Manual back action Pneumatic/automatic Crown splitters/ sectioning Thermo-plastic resin Advantages Disadvantages Atraumaticremoval of crown, useful withothersystems Long time application can cause ceramic cracks and pulp injury. Furthermore, it is time consuming and may require repair of restoration Atraumatictechnique, anddoesnot damagetherestoration, Dangerous when laser beam not directed properly, indicated for all ceramicrestorations Simpledesign, not expensive Theimpact of removal may beharmingtothepatient andtheligament Automaticreactivation, easetouseforall FPDstypes Difficult toascertainthepathof withdrawal, timeconsuming, costly Permits removal of FPD without damage to tooth and Permanent damage of FPDs, more time, expensive and unpleasant for periodontal tissues patient Atraumatictechnique Not recommendedif theopposingtoothisperiodontally affectedor has arestoration Crown splitters / sectioning Laser crown removal Ultrasonic crown removal Pneumatic/Automatic Thermoplastic resin (passive active method) Manual back action 1- crown disassembly (Coronal Access) 2- gaining access to apical area post removal Removal of restorative materials 3- removal of root filling material Silver Point removal Gutta percha removal Carrier-based Gutta percha removal Paste removal 4- Managing mishaps Ledges Canal blockage Broken instruments perforations Removal of restorative material Removal of posts Factor Post Length Core Type of Luting cement Findings Postsof greaterlengthcantakelongertoremove Increasingtheheight andwidthof cast corescanfacilitateremoval Compositecoresaroundpreformedpostscanbemoredifficult toremovethanamalgamcores Cast goldcores-easiertoreducethancoresmadewithnon-preciousmetals Postscementedwithzinc phosphatematerials- easier toremovethanthosecementedwithresinbasedlutes Position of most coronal portion of post Supracrestal –easiertoremove Subcrestal (i.e. fracturedposts) –moredifficult Tooth type/position Anteriorteeth–easierforpost removal Posteriorteeth–greaterdifficulty Diameter/adaptation of post Inappropriately adaptedposts–lesstimetoremove Wider, betteradaptedposts–difficult Ultrasonic Tips Post Removal Kit Ruddle Post Removal Kit Masserann Kit Thomas Post Removal Kit Removal of Fiber Post  Fiber posts are made up of carbon fiber, glass or quartz fibers in a composite matrix.  They are normally bonded into the root canal using dentine bonding agents.  Well-cemented posts can be drilled out using special burs ( The GyroTip).  Create a pilot channel down the centre of the post. The post can then be removed using Peeso drills, or Gates– Glidden burs.  Finally, remaining fragments are removed using the post drill. Type Removal Difficulty Suggested removal method Custom Moderate Ultrasonic, removal devices Simple Ultrasoics, Removal Devices Simple Simple Simple Ultrasonics, Removal Devices Ultrasonic, Removal Devices Ultrasonics, Ruddle Kit Fiber Moderate Drill out Manufacturers removal kit Ceramic Difficult Masserann kit Preformed: Non Threaded Threaded -Passive Tapered Parallel-sided - Active (Screw) Removal of Previous filling materials Silver Points Gutta percha Carrier-Based Gutta-Percha Sealers Pastes Microtube Removal Kit (IRS) 1- Heat 2- Ultrasonic Tips 3- Solvents and Paper Points “Wicking Action” a. Chloroform b. Eucalyptol c. Halothane d. Rectified turpentine e. Xylene a. EndoSolv E b. EndoSolv R ProTaper Universal Retreatment Kit Gates Glidden Burs Path Files In case of overextended GP try not to use either heat or solvents , it is recommended to use H-file 0.5-1mm beyond the apex using gentle clockwise rotation to allow the apical fragment to be engaged to the file, then retrieve Types of Carriers: Metal(difficult) ------ Plastic(easier) (St.St – Titanium) (Vectra- Polysulfone) Combination solvents & heat application & Steiglitz forceps Heat application to remove GP & H-file to remove the carrier The pastes may be Hard can be removed with abrasively coated straight ultrasonic tips, hand instruments apical to canal curvature , precurved file attached to file adaptor Other removal methods include heat, judicious use of end-cutting rotary NiTi instruments and small sized hand files with solvents such as Endosolv R and Endosolv E Micro-Debriders and paper points in conjunction with solvents Soft Easy to remove using irrigation & in a crown down mechanical technique. Removal Techniques: 1- coronal access create straight line access to all canal orifices 2- create staging platform the bud of GG altered by cutting at maximum cross section diameter 3- use of ultrasonic or IRS Removal Techniques: 1- coronal access create straight line access to all canal orifices 2- create staging platform the bud of GG altered by cutting at maximum cross section diameter 3- use of ultrasonic or IRS Removal Techniques: 1- coronal access create straight line access to all canal orifices 2- create staging platform the bud of GG altered by cutting at maximum cross section diameter 3- use of ultrasonic or IRS The level of instrument separation. The status of pulp & periradicular tissues. Whether the file can be removed or bypassed. Root thickness External root concavities Length of separated instrument Bounded or unbounded They are blockages & Ledges where there is a non instrumented area containing bacteria, necrotic tissues , Dentin mud, fibrosed or calcified tissues File precurving Picking Motion 1. 2. 3. 4. 5. 6. 7. 8. Sodium hypochlorite. Ultrasonics. Radiographic analysis. Magnification and lighting Transillumination Firm explorer pressure. Dyes. Color and texture. pathological Iatrogenic Treatment options Non surgical Surgical Coronal perforations Lateral Strip perforations Apical perforation time size location materials Calcium hydroxide advantages Biologically compatible with pulpal and periodontal tissue Disadvantages Necrosis at site of perforation Different level of cementum hyperplasia MTA Superior sealing ability Long setting time Biocompatible Difficult manipulation Hydrophilic particles Stimulate cementoblasts to produce matrix for cementum formation Biodentin Short setting time(12 min) Easy manipulation (capsule) Endosequence Setting reaction initiated by moisture Mechanical bond (nanoparticles) High ph alkalinity Premixed (syringe) Calcium Enriched Mixture it produces greater amount of calcium and phosphate ions which most likely forms hydroxyapatite in higher concentrations preferable as a furcal perforation repair making waste inevitable Good Prognosis Bad Prognosis Cohen`s pathways of the pulp, 11th edition, 2016, Kenneth M. Hargreaves and Louis H. Berman. (chapter 8) Endodontic science (two volumes), 2nd edition, 2009, Carlos Estrela. (chapter 23) Problems in endodontics, Etiology, diagnosis and treatment, 2009, Michael Hulsmann and Edgar Schafer. (chapter 20) Endodontology, an integrated biological and clinical view, 2013, Domenico Ricucci and Jose F. Siqueira Jr. (chapter 6) Clinical endodontics, 3rd edition, 2009, Leif Tronstad.