Presentation on theme: "dr VLADIMIR IVANOVIC, DDS, MSc, PhD, SDS"— Presentation transcript:
1dr VLADIMIR IVANOVIC, DDS, MSc, PhD, SDS Professor in Restorative Odontology & Endodontics,University of Belgrade, Republic of Serbia1
2Katarina Beljić- Ivanović Mirjana VujaškovićKatarina Beljić- IvanovićJugoslav IlićIvana BošnjakL E N G T HTHE WORKINGL E N G T HDETERMINING2
3TO LOCATE THE APICAL TERMINUS OF THE ROOT CANAL PREPARATION SEEKING WHERE,WHEN, WHY AND HOWJoshua MoshonovTO LOCATETHE APICALTERMINUSJulian WebberPaul DummerOF THE ROOTCANALPREPARATIONWilliam Saunders
4Articles that have been “guiding light” in creating my own standpoints, and directing “pathways” of this lecture by their philosopohy and conceptionApical limit of root canal instrumentation and obturation (1 & 2)D Ricucci & K Langeland, 1998, IEJApical terminus location of root canal treatment procedures.M-K Wu, P Wesselink & RE Walton, 2000, 4O’s & EndoConsiderations in working length determination.LRG Fava & JF Siqueira, 2000, Endodontic PracticeThe fundamental operating priciples of ERCLMDs.MH Nekoofar, SJ Hayes & PMH Dummer, 2006, IEJDetermination of true working length.R Mounce, 2007, EndoPractice
5METHODS OF DETERMINING THE WORKING LENGTH Predetermined “normal” tooth lengthPatient response to painTactile sensation of the therapistPaper point techniqueRadiographic methodElectronic locators5
6Patient response to pain - apical sensitivity Many false information, misleadings,& limitations; extremely subjective ==> unreliable- remnants of vital pulp tissue- pressure of the instrument tip via debris- destruction of PA tissues – no sensation- individual sensitivity – pain threshold- local anaesthesia- poor / no evidence in literatureIs it still in use, or gone to dental history ?
7Tactile sensation of the operator Very subjective, with limitations, often misleading=> unreliable- morphological irregularities: narrowing,calcification,multiple constrictions- tooth type & age- pathological resorption & wide AF- a few evidence in literatureStill advocated as very useful in hands of anexperienced practitioner to feel and identify AC !?
8Tactile sensation “Belgrade clinical study” M.V. & M.P. : 1984Literature data:to locate apical constrictionaccuracy varies: 30% - 44% - 60%with wide and random distributionof measured valuesReferent point from Rö apex :0.5mm in <25 yrs; mm in >25 yrsPreflaring enhances locatingof the AC, and increases accuracy: 32% up to 75%Precise in only 19%;with +/- 0.5 mm tolerance accuracy in 42%.Significant under and overestimationsup to 4.5 mm before and beyond RP !!!
9Paper point technique Claimed as the most precise method to determine: i) working length to the end of the canal, andii) min. apic. for.diam. (MAFD) in 3DAllows practitoner to “see” thecavosurface of the canalwith the precison of 0.25 mm;- apical patency technique -Wet (blood) / dry interface coincides with the location of the CSEnables to customise gutta-percha master cone 3Dupon the information from the PP
10Paper point techniqueDB RosenbergBy courtesy of J. Webber
11Paper point techniqueEven claimed as the most precise method in determining WL there is neither scientific nor clinical evidence in literature on its superiorityIn spite of being advocated by many endodontic experts,PP technique lacks in respect to morphological details andpathological state within the root canal and in periapical tissues“The use of PP as a simple device in sophisticated ways”- (Rosenberg)could be advised as an accessory / assisting mean to establish andconfirm final WL, since it is non-aggressive, “soft” method, andtherefore cannot injure tissues or disturb wound healing
12PREOPERATIVE – DIAGNOSTIC RADIOGRAPH IS MANDATORY ! Radiographic methodREVEALS, ASSISTS, BUT OFTEN GIVES AN “ILLUSORY TRUTH”PREOPERATIVE – DIAGNOSTIC RADIOGRAPH IS MANDATORY !
13. Radiographic apex and anatomical apex do not (always) coincide ! Apical foramen cannot be (always)visualised on a radiograph !Important details are not alwaysdetectable on the clinical radiograph
14Radiographic method “Belgrade clinical study” Literature data: M.V. & M.P.:1988Referent point from Rö apex :0.5mm in <25 yrs; mm in >25 yrsLiterature data:Accuracy widely rangesfrom 50% - 77% - up to 97%Precise in 51%;tolerance +/- 0.5 mm -> accurate in 68%;tolerance extended +/-1 mm accurate in 88%;Under and overestimations not over 2 mm !
15Measuring file is longer than it appears radiographically ! When instrument is short of the Rö apexsurprisingly is beyond AF in 43% !I.B.If AC is 0.5 mm before apex then 66% of all measurements are “beyond” !
16but could be solved successfully NO DOUBT – BEYONDbut could be solved successfully22
17When short of the Rö apex it is actually closer to the AF ! “... radiographic working length ending mm short of the radiographic apex provides, more often than expected,a basis for unintentional overinstrumentation”
18But could be solved successfully NO DOUBT – SHORTBut could be solved successfully12Radiographs are indispensable for calculating,but not for determining WL !
19Radiovisiography - RVG Digital radiographyK..B-I.37Assisted by RVG, only !S. AndjelkovicRadiovisiography - RVG
20Digital radiography - RVG Quantifies distancesImage could be varied by software programmeFine file tip – low contrast structures –affect visualisation and measuring precisionBetter results with #15 or #20 filesImage quality bellow conventional RöInferior to ELs – longer measurementsS. Andjelkovic20
21Adequate radiographs, knowledge of anatomy, Radiographic method relies still on manyassumptions, arbitrary calculations, averages,speculations and “illusory images”,that add to the confusion rather than giving solution !“GIVE LOCATORS A CHANCE”Adequate radiographs, knowledge of anatomy,and tactile sense, and not “apex locators” -- will help to determine apical constriction !21
22ELECTRONIC FORAMEN LOCATORS ELECTRONIC APEX LOCATORSELECTRONIC FORAMEN LOCATORSERCLMD, ”lot of words descriptive” – no lengthCLASSIFICATION of EFLsResistance-based devices ILow frequency oscillation devices IIHigh frequency (capacitance-based) devices IICapacitance & reistance device (access. look-up table) IVVoltage gradient-based devices ??Two frequences (impedance diference)-based devices IIITwo frequences (impedance ratio-quotient) devices IIIMulti frequency-based devices III“The use of “generation X” to describe and clasify these devices is unhelpful, unscientific and perhaps best suited to marketing issues”These are the very same devices, but just under different brand-name,showing how market functions and manufacturers „cooperate“
23In vitro (ex vivo) measuring the accuracy of EFLs - variables influencing and affecting results -Embedding media - simulate clinical conditions (peridontal ligament)Electrical properties of intracanal solution:extreme conductivity and ion concentration (type of EFL)File size in respect to the diameter of the AC and AF:wise to use smooth canal instruments - less damage to fine structuresType of EFL: the newer model the better and more consistent results
24Variables influencing and affecting results of ex vivo measuring the accuracy of EFLs:Preflaring: improves determination of apical diameter andfirst file that binds, stabilises readings, increases precisionRange of tolerance: from +/- 0.1 mm, mostly +/- 0.5 mm, up to 2 mm;the wider the range the higher the percent of EFL accuracy !- Apical land mark chosen to determine “real/actual length” (RA / AL)Most are valuable / useful for practice; majority was conductedin single rooted / canal teeth and suffer of too many variables !
25Differences bellow 0.5 mm are clinically not significant Are differences between real values and on EFL’s significant ?Figures/marks on a display of EFL’s scales do not represent values in mm !303300Differences bellow 0.5 mm are clinically not significantdue to our manual abilities !
26In clinical use to wait for 3-5 seconds to achieve stable reading ! What about occasionally unstable readings- bouncing indicating marks ?In clinical use to wait for 3-5 seconds to achieve stable reading !
27Tolerate small differences which are not noticeable clinically ? Bellow 0.5 mm !Differences clinically acceptable !!
28How strong readings on a display correspond to the real values on a high-tech measuring instrument ? 0.012– mm0.022– mmFar away of any concern!Precision and high resolution !Extremely small distorsions from the real measures!
29Indicate high level of resolution ! How exact readings on a display correspond to the real valueson the high-tech measuring instrument ? What do they indicate ?What is the clinical relevance ?=0.20mm=0.16mm< 0.06 mm0.001 mmIndicate high level of resolution !Differences far bellow clinically tolerable +/- 0.5 mm !!The closer to the apex, the more precise the readings are & higher is the resolution!!
30Can we follow with confidence what display indicates upon manufacturer’s instructions ?EFLs scales do not represent values in mm !Four yellow segments indicate region between AF and AC (0.5 – 1.0 mm) !
31Follow what display indicates and manufacturers instructions, but ”filtrate” and reconsider unusual and “strange” readings !!Three green segments indicate region of the apical constricion (~1.0 mm)
32Do different foramen locators display the same values for the same distance in the same root canal ?Until spreader reached plastic barrierTip of the finger spreader to the flatplastic surface placed firmly at theplane of the anatomical foramen !
34Do different foramen locators display the same values for the same distance in the same root canal ? No, they do not !
35351 (340) 307 (350) 193 (300) 169 (202) Raypex 5 Propex I Apex NRG XFR Distance between warning “beyond foramen” => reading foramen=> ”switch” to one mark/segment “short of foramen”Electronic foramen locatorfrom – torange in mresolution / “subtlety”Raypex 5Propex IApex NRG XFRDentaport ZXApex Pointer +(m)193 (300)351 (340)0.00.1– 380(48)Apex307 (350)Apex(202)AP EX
36Different foramen locators show different values with different level of resolution for the same distancein the same root canal !All deviations are far bellow range of clinicallyacceptable tolerance of +/- 0.5 mm, therefore theydo not significantly influence the accuracy of EFLsin locating apical foramen !!
37In vivo studies - on teeeth to be extracted: more realistic / relevant / reliable information useful for practitionersFactors that affect readings and/or accuracy of EFLs:- Vital – necrotic cases- Preflaring- Diameter of the minor and major foramen (pathol. – instrum.)- Size of the measuring file- Type of material the measuring file is made of- Canal content: infl. pulp tissue, puss, detritus; empty/dry- Conductive properties and ions concentration of irrigating solution- Tooth type: front - posterior / single – multi canal
38No affect on readings and accuracy: More consistent, straight forward, faster and precise readings when:- coronal /middle/ portion preflared- pulp tissue extirpated – debris removed- foramen is not enlarged by periapical pathosis / instrumentation- size of the file coincides with lumen of the apical portion- moderately conductive irrigating solution: 2% NaOCl, CHX, EDTANo affect on readings and accuracy:- Tooth type: front - posterior / single – multi rooted (canal)- Type of material the measuring file is made of
39Contradictory & controversial results / statements on: - vital vs. necrotic- moist vs. dry: type of EFL- high conductive vs. low conductive irrigant: type of EFLAdverse effect on readings:- PA lesions associated with destruction of PL, AF, AC and bone- wide open AF in immature teeth- extremes in conductive properties of a solution in the canal:saline vs. destilled water
40Variables influencing clinical results of EFLs accuracy : (varies from 15% up to 100%)- method to establish precision of the locator:micrsocsopy measurement - software programmes for extractedteeth samples vs. comparison with clinical radiograph- range of tolerance/targeted interval:+/- 0.5; +/- 1.0; +/- 1.5 mm; higher tolerance -> higher % of accuracymark on a display chosen to be “apical terminus” for EWL:“00” / “Apex” vs. “-0.5”/”AC; -1.0; yellow or green segment –or each operator will chose the mark that he wants to call hisOWN APICAL TERMINUS- anatomical land mark chosen to measure distance from the file tip:AC & CDJ vs. AF & AnApManufacturers should define clearly which lendmark their product locates !
41“Belgrade clinical studies on EFLs” M P, M V & V I : in early 80’s of the last centuryDomestic hand-made device “Diapex”“Odontometer” – Goof, DK
42“Belgrade clinical studies on EFLs” M.V. & D. I.: 1996M.P & M.V. :Referent point from Rö apex :0.5mm in <25 yrs; mm in >25 yrs“Odontometer”Alternating current impedancemeasuring device- in dry canalPrecise in 67% of vital teeth,and in 76% of teeth with necrotic pulp,with +/- 0.5 mm range of tolerance.Mostly underestimations of mm !Precise in 77% with +/- 0.5 mm tolerance.Overestimations of mm in only 4% !
43Accuracy of EFLs checked in clinical situation by Rö ? Traditionally EFLs accuracy has been corroborated by Rö, but any correction of the file position according to Rö projections would invariably lead to overextension !Comparison of precision of EFLs with Rö is not accurate because Rö is unreliable method in determining AC & AF !
44“Belgrade in vivo studies” In vivo - in molars and multirooted premolars to be extracted:30 canals per locator !“Propex I”: Dentsply/MAILLEFER (D. Nobs & S. Fultinavicius)“Raypex 5”: VDW (L. Satanovskij)“Apex NRG XFR”: Medic NRG (M. Zach, A. Beker, E. Friedman)“ApexPointer+”: MicroMega (C. Dort & A. Stephany)“Dentaport ZX”: J. Morita (J. Bohnes)
45tangential line to the AF Referent point wastangential line to the AFMark on a displayindicated AF:“0.0”, “Apex”, “red segment”
46NRG XFR small SD - consistent measuring; no beyond AF Mean distance from the file tip to the AF - in vivo determinedElectronic foramen locatorMean (+/- SD)Beyond AFApex NRG XFRDentaport ZXPropex IRaypex 5Apex Pointer +Ø(0.079)(0.222)2;(0.149)9; (0.102)(0.142)3;1;(0.168)Majority showed high SD – dispersion of valuesAll EFLs 100% precise within 0.2 mm range of tolerance;Seldom overestimations with small values - clinically acceptableNRG XFR small SD - consistent measuring; no beyond AF
47“When apical foramen is located the position of the apical constriction (if exists)can be estimated”
48Always have preoperative radiograph and stay within confines of the root canal !K..B-I.Determining WL upon preop Rö and EFL, only !
49TRUST in EFLs , BUT NOT BLINDLY !! Extreme narrow canals: Rö and EFL WL upon preop RVG, and EFL, only !!K..B-I.TRUST in EFLs ,BUT NOT BLINDLY !!
50Crown-down tapered preparation; WL - 0.25 mm before AF: tactile sensation, EFL, Rö and PP;rotary NiTi instrumentation & cold lateralCOMBINING ANDCOMPARING SEVERAL METHODSGIVE MORE CONFIDENCE,ACCURACY AND SUCCESS THANUSING ONLY ONE OR EVEN NONE !
5136 46 PREDICTABLE, RELIABLE AND SUCCESSFUL ENDODONTICS Let’s produce perls of endodontic treatment giving always our best3646twin-like
52MANY THANKS FOR YOUR ATTENTION Regards from Belgrade !!!MANY THANKS FOR YOUR ATTENTION1997 th