dr VLADIMIR IVANOVIC, DDS, MSc, PhD, SDSProfessor in Restorative Odontology & Endodontics, University of Belgrade, Republic of Serbia

dr VLADIMIR IVANOVIC, DDS, MSc, PhD, SDSProfessor in Restorative Odontology & Endodontics, University of Belgrade, Republic of Serbia

DE

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THE WORKING

THE WORKING

L E N G T H

L E N G T H

Mirjana Vujašković

Mirjana Vujašković

Katarina Beljić- Ivanović

Katarina Beljić- Ivanović

Ivana Bošnjak

Ivana BošnjakJugoslav Ilić

Jugoslav Ilić

L E N G T H

L E N G T H

SEEKING WHERE, SEEKING WHERE,

WHEN, WHY AND HOWWHEN, WHY AND HOW

TO LOCATE THE APICAL

TERMINUS

TO LOCATE THE APICAL

TERMINUS

OF THE ROOTCANAL

PREPARATION

OF THE ROOTCANAL

PREPARATION

Joshua Moshonov

Joshua Moshonov

Julian Webber

Julian Webber

Paul Dummer

Paul Dummer

William Saunders

William Saunders

Apical limit of root canal instrumentation and obturation (1 & 2) D Ricucci & K Langeland, 1998, IEJ

Apical terminus location of root canal treatment procedures. M-K Wu, P Wesselink & RE Walton, 2000, 4O’s & Endo

Considerations in working length determination. LRG Fava & JF Siqueira, 2000, Endodontic Practice

The fundamental operating priciples of ERCLMDs. MH Nekoofar, SJ Hayes & PMH Dummer, 2006, IEJ

Determination of true working length. R Mounce, 2007, EndoPractice

Apical limit of root canal instrumentation and obturation (1 & 2) D Ricucci & K Langeland, 1998, IEJ

Apical terminus location of root canal treatment procedures. M-K Wu, P Wesselink & RE Walton, 2000, 4O’s & Endo

Considerations in working length determination. LRG Fava & JF Siqueira, 2000, Endodontic Practice

The fundamental operating priciples of ERCLMDs. MH Nekoofar, SJ Hayes & PMH Dummer, 2006, IEJ

Determination of true working length. R Mounce, 2007, EndoPractice

Articles that have been “guiding light” in creating my own standpoints, and directing “pathways”

of this lecture by their philosopohy and conception

Articles that have been “guiding light” in creating my own standpoints, and directing “pathways”

of this lecture by their philosopohy and conception

Predetermined “normal” tooth lengthPatient response to painTactile sensation of the therapistPaper point techniqueRadiographic methodElectronic locators

Predetermined “normal” tooth lengthPatient response to painTactile sensation of the therapistPaper point techniqueRadiographic methodElectronic locators

METHODS OF DETERMINING THE WORKING LENGTH

METHODS OF DETERMINING THE WORKING LENGTH

Patient response to pain - apical sensitivity Patient 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 literature

Is it still in use, or gone to dental history ?

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 literature

Is it still in use, or gone to dental history ?

Tactile sensation of the operatorTactile 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 literature

Still advocated as very useful in hands of an experienced practitioner to feel and identify AC !?

Very subjective, with limitations, often misleading => unreliable - morphological irregularities: narrowing, calcification, multiple constrictions - tooth type & age - pathological resorption & wide AF - a few evidence in literature

Still advocated as very useful in hands of an experienced practitioner to feel and identify AC !?

Tactile sensationTactile sensation

Precise in only 19%;with +/- 0.5 mm tolerance accuracy in 42%.

Significant under and overestimations up to 4.5 mm before and beyond RP !!!

Precise in only 19%;with +/- 0.5 mm tolerance accuracy in 42%.

Significant under and overestimations up to 4.5 mm before and beyond RP !!!

M.V. & M.P. : 1984 M.V. & M.P. : 1984

Literature data: to locate apical constriction

accuracy varies: 30% - 44% - 60%with wide and random distribution

of measured values

Literature data: to locate apical constriction

accuracy varies: 30% - 44% - 60%with wide and random distribution

of measured values

Preflaring enhances locating of the AC, and increases

accuracy: 32% up to 75%

Preflaring enhances locating of the AC, and increases

accuracy: 32% up to 75%

Referent point from Rö apex :0.5mm in <25 yrs; 1.0 mm in >25 yrs

“Belgrade clinical study” “Belgrade clinical study”

Paper point techniquePaper point technique

Claimed as the most precise method to determine: i) working length to the end of the canal, and ii) min. apic. for.diam. (MAFD) in 3D

Allows practitoner to “see” the cavosurface of the canal with the precison of 0.25 mm; - apical patency technique -

Wet (blood) / dry interface coincides with the location of the CS

Enables to customise gutta-percha master cone 3D upon the information from the PP

Claimed as the most precise method to determine: i) working length to the end of the canal, and ii) min. apic. for.diam. (MAFD) in 3D

Allows practitoner to “see” the cavosurface of the canal with the precison of 0.25 mm; - apical patency technique -

Wet (blood) / dry interface coincides with the location of the CS

Enables to customise gutta-percha master cone 3D upon the information from the PP

By courtesy of J. Webber By courtesy of J. Webber

DB Rosenberg DB Rosenberg

Paper point techniquePaper point technique

Paper point techniquePaper point technique

Even claimed as the most precise method in determining WL there is neither scientific nor clinical evidence in literature on its superiority

In spite of being advocated by many endodontic experts, PP technique lacks in respect to morphological details and pathological state within the root canal and in periapical tissues

““The use of PP as a simple device in sophisticated ways”- The use of PP as a simple device in sophisticated ways”- ((RosenbergRosenberg))

could be advised as an accessory / assisting mean to establish and could be advised as an accessory / assisting mean to establish and confirm final WL, since it is non-aggressive, “soft” method, and confirm final WL, since it is non-aggressive, “soft” method, and therefore cannot injure tissues ortherefore cannot injure tissues or disturb disturb wound healing wound healing

Even claimed as the most precise method in determining WL there is neither scientific nor clinical evidence in literature on its superiority

In spite of being advocated by many endodontic experts, PP technique lacks in respect to morphological details and pathological state within the root canal and in periapical tissues

““The use of PP as a simple device in sophisticated ways”- The use of PP as a simple device in sophisticated ways”- ((RosenbergRosenberg))

could be advised as an accessory / assisting mean to establish and could be advised as an accessory / assisting mean to establish and confirm final WL, since it is non-aggressive, “soft” method, and confirm final WL, since it is non-aggressive, “soft” method, and therefore cannot injure tissues ortherefore cannot injure tissues or disturb disturb wound healing wound healing

Radiographic method Radiographic method

REVEALS, ASSISTS, BUT OFTEN GIVES AN “ILLUSORY TRUTH”

REVEALS, ASSISTS, BUT OFTEN GIVES AN “ILLUSORY TRUTH”

PREOPERATIVE – DIAGNOSTIC RADIOGRAPH IS MANDATORY !PREOPERATIVE – DIAGNOSTIC RADIOGRAPH IS MANDATORY !

Radiographic apex and anatomical apex do not (always) coincide !Radiographic apex and anatomical apex do not (always) coincide !

..

Apical foramen cannot be (always) visualised on a radiograph !

Apical foramen cannot be (always) visualised on a radiograph !

RöRö

AA

Important details are not alwaysdetectable on the clinical radiograph

Important details are not alwaysdetectable on the clinical radiograph

M.V. & M.P.:1988 M.V. & M.P.:1988

Referent point from Rö apex : 0.5mm in <25 yrs; 1.0 mm in >25 yrs

Precise in 51%;tolerance +/- 0.5 mm -> accurate in 68%;

tolerance extended +/-1 mm accurate in 88%;Under and overestimations not over 2 mm !

Precise in 51%;tolerance +/- 0.5 mm -> accurate in 68%;

tolerance extended +/-1 mm accurate in 88%;Under and overestimations not over 2 mm !

Literature data:Accuracy widely ranges

from 50% - 77% - up to 97%

Literature data:Accuracy widely ranges

from 50% - 77% - up to 97%

Radiographic method Radiographic method “Belgrade clinical study” “Belgrade clinical study”

Measuring file is longer than it appears radiographically !Measuring file is longer than it appears radiographically !

When instrument is short of the Rö apex surprisingly is beyond AF in 43% !

When instrument is short of the Rö apex surprisingly is beyond AF in 43% !

If AC is 0.5 mm before apex then 66% of all measurements are “beyond” !If AC is 0.5 mm before apex then 66% of all measurements are “beyond” !

I.B. I.B.

NO DOUBT – BEYONDbut could be solved successfully

NO DOUBT – BEYONDbut could be solved successfully

2222

When short of the Rö apex it is actually closer to the AF !When short of the Rö apex it is actually closer to the AF !

“... radiographic working length ending 0 - 2 mm short of the radiographic apex provides, more often than expected,

a basis for unintentional overinstrumentation”

“... radiographic working length ending 0 - 2 mm short of the radiographic apex provides, more often than expected,

a basis for unintentional overinstrumentation”

NO DOUBT – SHORT But could be solved successfully

NO DOUBT – SHORT But could be solved successfully

1212

Radiographs are indispensable for Radiographs are indispensable for calculatingcalculating,, but not for determining WL !but not for determining WL !

K..B-I.

Radiovisiography - RVGRadiovisiography - RVG

Digital radiography Digital radiography

Assisted by RVG, only ! Assisted by RVG, only !

3737

S. Andjelkovic S. Andjelkovic

Digital radiography - RVGDigital radiography - RVG

Quantifies distances Image could be varied by software programme Fine file tip – low contrast structures – affect visualisation and measuring precision Better results with #15 or #20 files Image quality bellow conventional Rö Inferior to ELs – longer measurements

Quantifies distances Image could be varied by software programme Fine file tip – low contrast structures – affect visualisation and measuring precision Better results with #15 or #20 files Image quality bellow conventional Rö Inferior to ELs – longer measurements

S. Andjelkovic S. Andjelkovic

Radiographic method relies still on many assumptions, arbitrary calculations, averages,

speculations and “illusory images”,that add to the confusion rather than giving solution !

Radiographic method relies still on many assumptions, arbitrary calculations, averages,

speculations and “illusory images”,that add to the confusion rather than giving solution !

Adequate radiographs, knowledge of anatomy, and tactile sense, and not “apex locators” - - will help to determine apical constriction !

Adequate radiographs, knowledge of anatomy, and tactile sense, and not “apex locators” - - will help to determine apical constriction !

“GIVE LOCATORS A CHANCE” “GIVE LOCATORS A CHANCE”

ELECTRONIC FORAMEN LOCATORSELECTRONIC FORAMEN LOCATORSELECTRONIC APEX LOCATORSELECTRONIC APEX LOCATORS

Resistance-based devices I Low frequency oscillation devices II High frequency (capacitance-based) devices II Capacitance & reistance device (access. look-up table) IV Voltage gradient-based devices ?? Two frequences (impedance diference)-based devices III Two frequences (impedance ratio-quotient) devices III Multi 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”

“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“ These are the very same devices, but just under different brand-name,

showing how market functions and manufacturers „cooperate“

ERCLMD, . . . - ”lot of words descriptive” – no lengthERCLMD, . . . - ”lot of words descriptive” – no lengthCLASSIFICATION of EFLsCLASSIFICATION of EFLs

- Embedding media - simulate clinical conditions (peridontal ligament)- Embedding media - simulate clinical conditions (peridontal ligament)

- Electrical properties of intracanal solution: extreme conductivity and ion concentration (type of EFL)- 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 structures- File size in respect to the diameter of the AC and AF: wise to use smooth canal instruments - less damage to fine structures

In vitro (ex vivo) measuring the accuracy of EFLsIn vitro (ex vivo) measuring the accuracy of EFLs

- Type of EFL: the newer model the better and more consistent results- Type of EFL: the newer model the better and more consistent results

- variables influencing and affecting results - - variables influencing and affecting results -

Variables influencing and affecting results of ex vivo measuring the accuracy of EFLs:Variables influencing and affecting results of ex vivo measuring the accuracy of EFLs:

- Preflaring: improves determination of apical diameter and first file that binds, stabilises readings, increases precision- Preflaring: improves determination of apical diameter and first file that binds, stabilises readings, increases precision

- Range 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 ! - Range 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)- 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 ! Most are valuable / useful for practice; majority was conductedin single rooted / canal teeth and suffer of too many variables !

Differences bellow 0.5 mm are clinically not significant due to our manual abilities !

Differences bellow 0.5 mm are clinically not significant due to our manual abilities !

Are differences between real values and on EFL’s significant ? Are differences between real values and on EFL’s significant ?

303303

Figures/marks on a display of EFL’s scales do not represent values in mm ! Figures/marks on a display of EFL’s scales do not represent values in mm !

300300

What about occasionally unstable readings - bouncing indicating marks ?

What about occasionally unstable readings - bouncing indicating marks ?

In clinical use to wait for 3-5 seconds to achieve stable reading !In clinical use to wait for 3-5 seconds to achieve stable reading !

Tolerate small differences which are not noticeable clinically ?Tolerate small differences which are not noticeable clinically ?

Bellow 0.5 mm !Bellow 0.5 mm !300m

202m

Differences clinically acceptable !! Differences clinically acceptable !!

How strong readings on a display correspond to the real values on a high-tech measuring instrument ?How strong readings on a display correspond to the real values on a high-tech measuring instrument ?

Precision and high resolution ! Extremely small distorsions from the real measures!

Precision and high resolution ! Extremely small distorsions from the real measures!

0.012– 0.038 mm 0.012– 0.038 mm

0.022– 0.065 mm 0.022– 0.065 mm

Far away of any concern!Far away of any concern!

How exact readings on a display correspond to the real values on the high-tech measuring instrument ? What do they indicate ? What is the clinical relevance ?

How exact readings on a display correspond to the real values on the high-tech measuring instrument ? What do they indicate ? What is the clinical relevance ?

< 0.06 mm< 0.06 mm

0.35-0.19=0.16mm 0.35-0.19=0.16mm

1.45 -1.25=0.20mm1.45 -1.25=0.20mm

Differences far bellow clinically tolerable +/- 0.5 mm !!Differences far bellow clinically tolerable +/- 0.5 mm !!

0.001 mm 0.001 mm

Indicate high level of resolution !Indicate high level of resolution !

The closer to the apex, the more precise the readings are & higher is the resolution!!The closer to the apex, the more precise the readings are & higher is the resolution!!

Can we follow with confidence what display indicates upon manufacturer’s instructions ? Can we follow with confidence what display indicates upon manufacturer’s instructions ?

Four yellow segments indicate region between AF and AC (0.5 – 1.0 mm) !

Four yellow segments indicate region between AF and AC (0.5 – 1.0 mm) !

EFLs scales do not represent values in mm ! EFLs scales do not represent values in mm !

Three green segments indicate region of the apical constricion (~1.0 mm) Three green segments indicate region of the apical constricion (~1.0 mm)

Follow what display indicates and manufacturers instructions,but ”filtrate” and reconsider unusual and “strange” readings !! Follow what display indicates and manufacturers instructions,but ”filtrate” and reconsider unusual and “strange” readings !!

Until spreader reached plastic barrierUntil spreader reached plastic barrier

Tip of the finger spreader to the flatplastic surface placed firmly at theplane of the anatomical foramen !

Tip of the finger spreader to the flatplastic surface placed firmly at theplane of the anatomical foramen !

Do different foramen locators display the same values for the same distance in the same root canal ?

Do different foramen locators display the same values for the same distance in the same root canal ?

Do different foramen locators display the same values for the same distance in the same root canal ?Do different foramen locators display the same values for the same distance in the same root canal ?

No, they do not !No, they do not !

Electronic foramen locator

from – to range in m resolution / “subtlety”

Raypex 5

Propex I

Apex NRG XFR

Dentaport ZX

Apex Pointer +

0 - 508 - 7010 - 508 - 701

0 - 354 - 7050 - 354 - 705

0 - 305 – 380 0 - 305 – 380

0 - 367 - 6740 - 367 - 674

0 - 143 - 3120 - 143 - 312

Distance between warning “beyond foramen” => reading foramen=> ”switch” to one mark/segment “short of foramen”

Distance between warning “beyond foramen” => reading foramen=> ”switch” to one mark/segment “short of foramen”

193 (300)193 (300)

351 (340)351 (340)

75 (48)75 (48)

307 (350)307 (350)

169 (202)169 (202)

0.0 0.1

- 0.0 Apex 0.25- 0.0 Apex 0.25

Apex Apex

AP EX 0.0 0.1

(m)(m)

Different foramen locators show different values with different level of resolution for the same distance

in the same root canal !

Different foramen locators show different values with different level of resolution for the same distance

in the same root canal !

All deviations are far bellow range of clinically acceptable tolerance of +/- 0.5 mm, therefore they do not significantly influence the accuracy of EFLs

in locating apical foramen !!

All deviations are far bellow range of clinically acceptable tolerance of +/- 0.5 mm, therefore they do not significantly influence the accuracy of EFLs

in locating apical foramen !!

more realistic / relevant / reliable information useful for practitioners more realistic / relevant / reliable information useful for practitioners

Factors that affect readings and/or accuracy of EFLs:Factors that affect readings and/or accuracy of EFLs:

- Vital – necrotic cases - Vital – necrotic cases

- Preflaring - Preflaring

- Canal content: infl. pulp tissue, puss, detritus; empty/dry - Canal content: infl. pulp tissue, puss, detritus; empty/dry

- Conductive properties and ions concentration of irrigating solution- Conductive properties and ions concentration of irrigating solution

- Diameter of the minor and major foramen (pathol. – instrum.) - Diameter of the minor and major foramen (pathol. – instrum.)

- Size of the measuring file - Size of the measuring file

- Tooth type: front - posterior / single – multi canal - Tooth type: front - posterior / single – multi canal

- Type of material the measuring file is made of - Type of material the measuring file is made of

In vivo studies - on teeeth to be extracted:In vivo studies - on teeeth to be extracted:

More consistent, straight forward, faster and precise readings when:More consistent, straight forward, faster and precise readings when:

- coronal /middle/ portion preflared - coronal /middle/ portion preflared

- pulp tissue extirpated – debris removed - pulp tissue extirpated – debris removed

- moderately conductive irrigating solution: 2% NaOCl, CHX, EDTA- moderately conductive irrigating solution: 2% NaOCl, CHX, EDTA

- foramen is not enlarged by periapical pathosis / instrumentation- foramen is not enlarged by periapical pathosis / instrumentation

- size of the file coincides with lumen of the apical portion - size of the file coincides with lumen of the apical portion

No affect on readings and accuracy:No affect on readings and accuracy:

- Tooth type: front - posterior / single – multi rooted (canal) - Tooth type: front - posterior / single – multi rooted (canal)

- Type of material the measuring file is made of - Type of material the measuring file is made of

Contradictory & controversial results / statements on: Contradictory & controversial results / statements on:

- vital vs. necrotic - vital vs. necrotic

- moist vs. dry: type of EFL - moist vs. dry: type of EFL

- high conductive vs. low conductive irrigant: type of EFL- high conductive vs. low conductive irrigant: type of EFL

Adverse effect on readings:Adverse effect on readings:

- extremes in conductive properties of a solution in the canal: saline vs. destilled water- extremes in conductive properties of a solution in the canal: saline vs. destilled water

- PA lesions associated with destruction of PL, AF, AC and bone - PA lesions associated with destruction of PL, AF, AC and bone

- wide open AF in immature teeth- wide open AF in immature teeth

Variables influencing clinical results of EFLs accuracy : (varies from 15% up to 100%)

Variables influencing clinical results of EFLs accuracy : (varies from 15% up to 100%)

- mark 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 his OWN APICAL TERMINUS

- mark 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 his OWN APICAL TERMINUS

- range of tolerance/targeted interval: +/- 0.5; +/- 1.0; +/- 1.5 mm; higher tolerance -> higher % of accuracy- range of tolerance/targeted interval: +/- 0.5; +/- 1.0; +/- 1.5 mm; higher tolerance -> higher % of accuracy

- anatomical land mark chosen to measure distance from the file tip: AC & CDJ vs. AF & AnAp - anatomical land mark chosen to measure distance from the file tip: AC & CDJ vs. AF & AnAp

- method to establish precision of the locator: micrsocsopy measurement - software programmes for extracted teeth samples vs. comparison with clinical radiograph

- method to establish precision of the locator: micrsocsopy measurement - software programmes for extracted teeth samples vs. comparison with clinical radiograph

Manufacturers should define clearly which lendmark their product locates !Manufacturers should define clearly which lendmark their product locates !

M P, M V & V I : in early 80’s of the last century M P, M V & V I : in early 80’s of the last century

Domestic hand-made device “Diapex” Domestic hand-made device “Diapex” “Odontometer” – Goof, DK“Odontometer” – Goof, DK

“Belgrade clinical studies on EFLs” “Belgrade clinical studies on EFLs”

M.P & M.V. : 1988 - 1990 M.P & M.V. : 1988 - 1990

Precise in 77% with +/- 0.5 mm tolerance.Overestimations of + 0.5 mm in only 4% ! Precise in 77% with +/- 0.5 mm tolerance.Overestimations of + 0.5 mm in only 4% !

Referent point from Rö apex : 0.5mm in <25 yrs; 1.0 mm in >25 yrs

“Belgrade clinical studies on EFLs” “Belgrade clinical studies on EFLs”

Precise in 67% of vital teeth, and in 76% of teeth with necrotic pulp,

with +/- 0.5 mm range of tolerance. Mostly underestimations of -1.0 mm !

Precise in 67% of vital teeth, and in 76% of teeth with necrotic pulp,

with +/- 0.5 mm range of tolerance. Mostly underestimations of -1.0 mm !

M.V. & D. I.: 1996 M.V. & D. I.: 1996

“Odontometer”“Odontometer”

Alternating current impedance measuring device- in dry canalAlternating current impedance measuring device- in dry canal

Accuracy of EFLs checked in clinical situation by Rö ?Accuracy 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 !

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 !

“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)

“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)

“Belgrade in vivo studies”“Belgrade in vivo studies”In vivo - in molars and multirooted premolars to be extracted:In vivo - in molars and multirooted premolars to be extracted:

30 canals per locator ! 30 canals per locator !

Referent point was tangential line to the AF

Referent point was tangential line to the AF

Mark on a display indicated AF:

“0.0”, “Apex”, “red segment”

Mark on a display indicated AF:

“0.0”, “Apex”, “red segment”

Electronic foramen locator

Mean (+/- SD)

Beyond AF

Apex NRG XFR

Dentaport ZX

Propex I

Raypex 5

Apex Pointer +

0.148 (0.079)

0.187 (0.142)

ØØ

3; 3;

9; + 0.226 (0.102)9; + 0.226 (0.102)0.169 (0.149)

0.165 (0.222)

0.189 (0.168)

2; 2;

Mean distance from the file tip to the AF - in vivo determined Mean distance from the file tip to the AF - in vivo determined

1; + 0.1291; + 0.129

+ 0.076+ 0.131+ 0.076+ 0.131

+ 0.119+ 0.208+ 0.075

+ 0.119+ 0.208+ 0.075

Majority showed high SD – dispersion of valuesMajority showed high SD – dispersion of valuesAll EFLs 100% precise within 0.2 mm range of tolerance; All EFLs 100% precise within 0.2 mm range of tolerance; Seldom overestimations with small values - clinically acceptable Seldom overestimations with small values - clinically acceptable NRG XFR small SD - consistent measuring; no beyond AF NRG XFR small SD - consistent measuring; no beyond AF

“When apical foramen is located the position of the apical constriction (if exists)

can be estimated”

“When apical foramen is located the position of the apical constriction (if exists)

can be estimated”

Always have preoperative radiograph and stay within confines of the root canal !

Always have preoperative radiograph and stay within confines of the root canal !

Determining WL upon preop Rö and EFL, only !

K..B-I. K..B-I.

WL upon preop RVG, and EFL, only !! WL upon preop RVG, and EFL, only !!

Extreme narrow canals: Rö and EFLExtreme narrow canals: Rö and EFL

TRUST in EFLs , BUT NOT BLINDLY !!

K..B-I. K..B-I.

COMBINING ANDCOMPARING SEVERAL METHODSGIVE MORE CONFIDENCE, ACCURACY AND SUCCESS THANUSING ONLY ONE OR EVEN NONE !

COMBINING ANDCOMPARING SEVERAL METHODSGIVE MORE CONFIDENCE, ACCURACY AND SUCCESS THANUSING ONLY ONE OR EVEN NONE !

Crown-down tapered preparation; WL - 0.25 mm before AF:

tactile sensation, EFL, Rö and PP; rotary NiTi instrumentation & cold lateral

Crown-down tapered preparation; WL - 0.25 mm before AF:

tactile sensation, EFL, Rö and PP; rotary NiTi instrumentation & cold lateral

PREDICTABLE, RELIABLE AND SUCCESSFUL ENDODONTICS

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Let’s produce perls of endodontic treatment giving always our best

twin-like twin-like

Regards from Belgrade !!!

MANY THANKS FOR YOUR ATTENTIONMANY THANKS FOR YOUR ATTENTION

1997 th1997 th