Cleaning and Shaping I PDF

CLEANING AND SHAPING  OUTLINE Principles of Cleaning and shaping Endodontic Instruments Steps of Cleaning and Shaping General Considerations Criteria to Evaluate Clean...

CLEANING AND SHAPING  OUTLINE Principles of Cleaning and shaping Endodontic Instruments Steps of Cleaning and Shaping General Considerations Criteria to Evaluate Cleaning and Shaping NADA IBRAHIM - CLEANING & SHAPING 2  To cure or prevent ENDODONTIC periradicular periodontitis , and for patients to retain THERAPY AIM their natural teeth function and aesthetics. NADA IBRAHIM - CLEANING & SHAPING 3 BRIEF HISTORY 1852 1889 Arthur used small files for root William Rollins developed the first enlargement endodontic hand piece Schilder introduced the concept Gates glidden drills were introduced “cleaning and shaping” 1885 1974 NADA IBRAHIM - CLEANING & SHAPING 4 CLEANING AND SHAPING ¡ Cleaning: refers to removal of all contents of root canal system before and during shaping, that is organic subtracts, microflora, bacterial byproducts, food debris, caries, denticles, pulp stones, previous root canal filling materials and dentinal shavings. ¡ Shaping: refers to specific cavity form with design objectives. NADA IBRAHIM - CLEANING & SHAPING 5 PRINCIPLES OF CLEANING AND SHAPING The primary objectives in cleaning and shaping the root canal system are to do the following: 1. Remove infected soft and hard tissue 2. Give disinfecting irrigants access to the apical canal space 3. Create space for the delivery of medicaments and subsequent obturation 4. Retain the integrity of radicular structures NADA IBRAHIM - CLEANING & SHAPING 6 MECHANICAL 1. Complete and centered incorporation of the original canals into the prepared shape, meaning OBJECTIVE that all root canal surfaces are mechanically prepared. 2. Retain as much as cervical and radicular dentin as possible so as not to weaken the root structure, thereby preventing root fractures NADA IBRAHIM - CLEANING & SHAPING 7 BIOLOGIC 1. Confinement of instrumentation to the roots themselves OBJECTIVE 2. No forcing of necrotic debris beyond the foramen 3. Removal of all tissue from the root canal space 4. Creation of sufficient space for intra-canal medicaments NADA IBRAHIM - CLEANING & SHAPING 8 TECHNICAL OBJECTIVE 1. Continuously tapering funnel from the apex to the access cavity 2. Cross sectional diameter should be narrower at every point apically 3. The root canal preparation should flow with the shape of the original canal 4. Apical foramen should remain in its original position 5. Apical opening should be kept as small as practical NADA IBRAHIM - CLEANING & SHAPING 9  ¡Shaping must not only be carried out with respect to the individual and unique anatomy of each root canal but also in relation to the technique of and material for final obturation. -Schilder NADA IBRAHIM - CLEANING & SHAPING 10  ENDODONTIC INSTRUMENTS NADA IBRAHIM - CLEANING & SHAPING 11  Hand Instruments : Broaches and files INSTRUMENTS Rotary Instruments : gates glidden USED IN drill, Protaper , Profile, K3, Receproc RADICULAR Automated : sonic and ultrasonic PREPARATION lasers NADA IBRAHIM - CLEANING & SHAPING 12  Filing Motion 01 Push and Pull action, effective action during pulling. Best used with H-File Reaming Motion 02 Types of Insertion, rotation then retraction of instrument To be used in the apical third to prepare circular cross section to best fit the master cone Motions Turn and Pull ( combination reaming/filing) 03 Insertion with ¼ turn clockwise ( reaming), and file is withdrawn ( filing) Watch winding Motion 04 Back and forth oscillation of the file through 30-60 degrees of rotation FILING MOTION ¡ The term Filing indicates a push-pull action without rotation with the instrument NADA IBRAHIM - CLEANING & SHAPING 14 REAMING MOTION ¡ Repeated clockwise rotation of the instrument which will shave the canal walls and give a cross sectional preparation approximately round NADA IBRAHIM - CLEANING & SHAPING 15 TURN AND PULL/ REAMING ( COMBINATION) ¡ File is inserted with a quarter turn clockwise and apically directed pressure & then is subsequently withdrawn NADA IBRAHIM - CLEANING & SHAPING 16 WATCH WINDING ¡ Gentle right and left rocking motion , which causes the instrument to cut while a light inward pressure keeps the file engaged and progressing toward the apex NADA IBRAHIM - CLEANING & SHAPING 17 STEPS OF CLEANING AND SHAPING DEFINITIONS ¡ Initial files : the first file that binds at the apex at full working length ¡ MAF : the last file used for apical preparation ( usually 3 sizes larger than the initial file) ¡ Recapitulation: performed in between each successive enlarging file , irrespective of the technique used ¡ Involves the use of a small file to the whole working length ¡ This helps in clearing the apical portion and removing the debris which gets collected there NADA IBRAHIM - CLEANING & SHAPING 19  ACCESS PRINCIPLES ¡ Over enlargement or gouging during access significantly reduces structural strength , may lead to root fracture and non restorable conditions ¡ Rationally , the use of a cylindrical diamond bur, followed by a tapered fluted bur with non cutting tip and perhaps a small round bur is recommended. NADA IBRAHIM - CLEANING & SHAPING 20 CORONAL MODIFICATION Tools for Pre-Flaring : 1. Gates Gliddens 2. Dedicated NiTi instruments (orifice shapers) NADA IBRAHIM - CLEANING & SHAPING 21  CORONAL MODIFICATION Benefits of Coronal Modification: 1. Allows files unimpeded access to the apical one third 2. Gives the clinician better tactile control in directing small, adequately pre-curved negotiating files 3. Access of disinfecting irrigation solutions 4. Reduction of working length changes during canal preparation NADA IBRAHIM - CLEANING & SHAPING 22 CORONAL MODIFICATION ¡ If a canal is constricted, mineralized, or difficult to access, directed enlargement of the coronal portion prior to any deep entry into the root canal is beneficial ¡ This canal modification should be preceded by a scouting step, in which a small (eg #10) file is passively placed several millimeters into the root canal ¡ Pre- enalargement of the coronal portion of a root canal allows files unimpeded access to the apical one third and gives the clinician better tactile control in directing small, adequately pre-curved negotiating files. NADA IBRAHIM - CLEANING & SHAPING 23 WORKING LENGTH DETERMINATION Radiographs, tactile sensation, the presence of moisture on paper points, and the knowledge of root morphology have been used to determine the length of root canal systems NADA IBRAHIM - CLEANING & SHAPING 24 WORKING LENGTH DETERMINATION ¡ Currently the electronic apex locater is considered an accurate tool for determining working length. NADA IBRAHIM - CLEANING & SHAPING 25 WORKING LENGTH DETERMINATION ¡ Traditional treatment has held that canal preparation and subsequent obturation should terminate at the apical constriction, the narrowest diameter of the canal. ¡ This point is believed to coincide with the cementodentinal junction. ¡ The position and anatomy of the CDJ varies considerably from tooth to tooth, from root to root, and from NADA IBRAHIM - CLEANING & SHAPING wall to wall in each canal. 26  IT IS ADVOCATED TERMINATING THE PREPARATION IN NECROTIC CASES AT 0.5 TO 1MM SHORT NADA IBRAHIM - CLEANING & OF THE RADIOGRAPHIC APEX AND 1-2 MM SHORT OF THE RADIOGRAPHIC SHAPING 27 APEX IN CASES INVOLVING IRREVERSIBLE PULPITIS  Apex Locater Tips 1. 2. 3. 4. 5. Dry your canals Appropriate Pulling the file Just take a Charge it up ! File Size away from radiograph A dry canal will Make sure your give you a more Usually size 15, metal apex locater accurate or #20 for large filling/crowns has a decent reading. canals. charge or it Dry canals with may not be paper points. accurate  PATENCY FILE Definition: a small K-File (usually a size #10, or #15) that is passively extended 1mm beyond the apical foramen without enlarging it ¡ This step is to remove accumulated debris by recapitulation ¡ Small patency files can help clean up to the canal terminus during chemomechanical procedures. NADA IBRAHIM - CLEANING & SHAPING 29  PATENCY FILE AND GLIDE PATH PREPARATION ¡ The file that has reached the apical foramen has already formed a so – called glide path. ¡ Glide path means securing an open pathway to the canal terminus that subsequent engine driven instruments can follow. ¡ Glide path is created and secured with K-File size #10 and #15 used in watch winding or balanced force motion NADA IBRAHIM - CLEANING & SHAPING 30 RECAPITULATION ¡ Is important regardless of the technique selected ¡ Accomplished by taking a small file to the corrected working length to loosen accumulated debris, then flushing with irrigant (sodium hypochlorite) ¡ Recapitulation is performed between each successive enlarging instrument regardless of the cleaning and shaping technique NADA IBRAHIM - CLEANING & SHAPING 31  ¡ The initial canal size is a major determinant for the desired final apical diameter CANAL ¡ It is very important to maintain the original path of the canal ENLARGEMENT/ during preparation, otherwise, bacteria in the apical one third of the PREPARATION root canal may not be reached by sufficient amounts of an NADA IBRAHIM - CLEANING & SHAPING 32 antimicrobial agents  CANAL ENLARGEMENT/PREPARATION ¡ The shape of the access cavity is THE prerequisite that must be optimized before any canal preparation can take place ¡ The access cavity shape must allow instruments unimpeded access to the middle third NADA IBRAHIM of the - CLEANING root canal system & SHAPING 33  ¡ The initial canal size is a major determinant for the desired final apical diameter, with the second relevant dimension being the size that allows deep irrigation needle penetration NADA IBRAHIM - CLEANING & SHAPING 34  Apical enlargement has been CANAL broken down into 3 phases: ENLARGEMENT/ 1. Pre-enlargement PREPARATION 2. Apical enlargement 3. Apical finishing NADA IBRAHIM - CLEANING & SHAPING 35  CANAL ENLARGEMENT/PREPARATION Anatomic studies and clinical experience suggests that most teeth are 19-25 mm long. Most clinical crowns are approximately 10 mm long, and most roots range from 9-15 mm in length. Vertical root fractures and perforations are possible outcomes of excessive removal of radicular dentin in zones that have been termed Danger Zone NADA IBRAHIM - CLEANING & SHAPING 36  DANGER ZONE Distal Area in the Mesial Root in Mandibular Molars. NADA IBRAHIM - CLEANING & SHAPING 37  Size 30 FINAL APICAL SIZE ? ¡ Shuping et al. found that the additional antibacterial effect of sodium hypochlorite (NaOCl) only became evident after instrumentation exceeded ISO size 30-35 NADA IBRAHIM - CLEANING & SHAPING 38 NADA IBRAHIM - CLEANING & SHAPING 39  STEP BACK TECHNIQUE ¡ Incorporating a stepwise reduction of the working length for larger files, typically 1 mm or 0.5 mm steps, resulting in flared shapes with 0.05 and 0.10 taper ¡ Includes the use of a stainless-steel K-Files exploring the apical constriction and establishing working length ¡ Incrementally reducing the working length when using larger and stiffer instruments also reduced the incidence of preparation errors, in particular in curved canals NADA IBRAHIM - CLEANING & SHAPING 40  WHAT DOES THAT MEAN? NADA IBRAHIM - CLEANING & SHAPING 41  ¡ Tooth length determination STEP BACK ¡ Selection of initial file TECHNIQUE PHASE 1 ¡ Initial File is inserted into the canal to the full working length using a watch winding motion ( APICAL PREPARATION) until it becomes loose ¡ The procedure is repeated until the apical area is prepared at least THREE successive files after IF ¡ MAF – largest file that will reach the full working length NADA IBRAHIM - CLEANING & SHAPING 42  PHASE I – PREPARATION OF APICAL CONSTRICTION ¡ Apical preparation up to 3 files after the initial file, to the FULL WORKING LENGTH ¡ With recapitulation with a smaller file. Your last file in phase 1 is your MASTER FILE NADA IBRAHIM - CLEANING & SHAPING 43  PHASE II – PREPARATION OF THE REST OF THE CANAL ¡ Stepping backwards using larger size files while shortening working length (usually 1 mm) to obtain a flared preparation ¡ With recapitulation and irrigation between each file So , we increase the size, but decrease the length 1 mm each time NADA IBRAHIM - CLEANING & SHAPING 44 NADA IBRAHIM - CLEANING & SHAPING 45  DISADVANTAGES OF STEP BACK TECHNIQUE ¡ Difficult to irrigate apical region ¡ Extrusion of debris apically ¡ Time consuming ¡ Iatrogenic errors like ledge formation in curved canals ¡ Apical blockage ¡ Straightening of the canals NADA IBRAHIM - CLEANING & SHAPING 46  ¡ Straight line-access (flare the wall). ¡ Establish the WL with size #15 and instrument the canal with same size in watchwinding strokes to establish apical patency. ¡ Instrument the canal from #20-40. (each as far as it goes passively). PASSIVE ¡ Insert size #2 G.G without activation to a point where STEP BACK it binds, pull it back 1-1.5 mm then activate the G.G (#4 Gates-Glidden and reamer can be used in large canals) TECHNIQUE ¡ Confirm the WL before canal preparation. ¡ Flare the coronal 2-3 mm further with G.G ¡ Apical preparation with sequentially larger files from the working length. ¡ In curved canals it should be limited to #25-#30. NADA IBRAHIM - CLEANING & SHAPING 47 NADA IBRAHIM - CLEANING & SHAPING 48 NADA IBRAHIM - CLEANING & SHAPING 49  ¡ Insertion : clockwise 60 Degrees BALANCED FORCE ¡ Apical pushing with rotation of 120 degrees TECHNIQUE counterclockwise NADA IBRAHIM - CLEANING & SHAPING ¡ Removal by giving 60 degrees rotation clockwise 50 NADA IBRAHIM - CLEANING & SHAPING 51  CROWN DOWN TECHNIQUE ¡ Enlarge the coronal third of the canal with progressively smaller GG drills or with other rotary instruments ¡ This technique relies more on coronal flaring and then the determination of the working length later in the procedure ¡ This technique consisted of an exploratory action with a small file NADA IBRAHIM - CLEANING & SHAPING 52  CROWN DOWN TECHNIQUE ¡ After preflaring of the canal orifices. This can be done by using hand instruments, Gates- Glidden drills or the nickle-titanium rotary instruments. After that a glide-path is created by using # 10 or 15 file. ¡ The crown down approach begins with larger Gates-Glidden first (size 4 or 5), followed by smaller Gates-Gliddens are worked into the canal with additional 1 mm to complete coronal flaring. ¡ A care should be taken to avoid carrying all the Gates-Glidden drills to same level which may lead to excessive cutting of the dentin. NADA IBRAHIM - CLEANING & SHAPING 53  ¡ Frequent irrigation with sodium hypochlorite and recapitulation with a smaller file (usually No. 10 file) to prevent canal blockage. ¡ After establishing coronal and mid root enlargement, explore the canal and establish the working length with small instruments (# 10 or 15 file) ¡ Introduce larger files to coronal part of the canal and prepare it. Subsequently introduce progressively smaller number files deeper into the canal in sequential order and prepare the apical part of the canal ¡ Final apical preparation is prepared and finished along with frequent irrigation of the canal system. NADA IBRAHIM - CLEANING & SHAPING 54 NADA IBRAHIM - CLEANING & SHAPING 55  ¡ Removal of tissue debris coronally, thus minimizing BIOLOGICAL the extrusion of debris periapically ADVANTAGES ¡ Reduction of postoperative sensitivity which could OF CROWN result from periapical extrusion of debris. DOWN ¡ Greater volumes of irrigants can reach in canal TECHNIQUE: irregularities in early stages of canal preparation because of coronal flaring. ¡ Better dissolution of tissue with increased penetration of the irrigants NADA IBRAHIM - CLEANING & SHAPING 56  ¡ Enhanced tactile sensation with instruments because of removal of coronal interferences. CLINICAL ¡ Flexible (smaller) files are used in apical portion of the canal; whereas larger (stiffer) files need not be forced but kept short ADVANTAGES of the apex. This decrease the chance for canal ledging, transportation and perforation. OF CROWN ¡ Straight line access to root curves and canal junctions. DOWN ¡ Provides more space for irrigants. TECHNIQUE: ¡ Enhance canal debridement and Decrease frequency of canal blockages. ¡ Desired shape of canal can be obtained that is narrow apically and wider coronally. This provides better room for Gatta Percha NADA IBRAHIM - CLEANING & SHAPING condensation to obtain proper three dimensional obturation57 of the root canal.  THE FOLLOWING PRINCIPLES AND CONCEPTS SHOULD BE APPLIED REGARDLESS OF THE INSTRUMENTS OR GENERAL TECHNIQUES SELECTED CONSIDERATIONS THE FOLLOWING PRINCIPLES AND CONCEPTS SHOULD BE APPLIED REGARDLESS OF THE INSTRUMENTS OR TECHNIQUES SELECTED 1. Initial canal exploration is always performed with smaller files to gauge canal size, shape, and configuration 2. Files are always manipulated in a canal filled with an irrigant or lubricant present, NEVER A DRY CANAL 3. Copious irrigation is used between each instrument in the canal 4. Coronal pre-flaring will facilitate placing larger working length files, and will reduce procedural errors such as loss of working length and canal transportation 5. Apical canal enlargement is gradual , using sequentially larger files from apical to coronal, regardless of flaring technique 6. Instrument binding should be avoided, files are teased to length using watch winding action NADA IBRAHIM - CLEANING & SHAPING 59 THE FOLLOWING PRINCIPLES AND CONCEPTS SHOULD BE APPLIED REGARDLESS OF THE INSTRUMENTS OR TECHNIQUES SELECTED 1. Regardless of the technique , after each insertion the file is removed and the flutes are cleaned of debris. Debris are removed by wiping the flutes with an alcohol soaked gauze or cotton roll 2. Recapitulation is done to loosen debris by rotating the master apical file at the correct working length followed by irrigation to mechanically remove the material NADA IBRAHIM - CLEANING & SHAPING 60  CRITERIA FOR EVALUATING CLEANING AND SHAPING ¡ Following cleaning and shaping procedures the canal should exhibit “ glassy smooth” walls and there should be no evidence of unclean dentin filings, debris, or irrigant in the canal ¡ This is determined by pressing the MAF against each wall in an outward stroke NADA IBRAHIM - CLEANING & SHAPING 61  CRITERIA FOR EVALUATING CLEANING AND SHAPING ¡ Shaping is evaluated by assessing the canal taper and identifying the apical configuration. ¡ For obturation with lateral compaction – finger spreader should go loosely to within 1.00 mm of the corrected working length ¡ For warm vertical compaction – the plugger should reach to within 5 mm of the corrected working length NADA IBRAHIM - CLEANING & SHAPING 62 ANY QUESTIONS?!