Tạp chí Nội Nha tháng 5&6/ 2013 Vol 6 No 3

Tạp chí nội nha tháng 5 6 2013 vol6 no 3

Performance Refi ned

NEW

1-800-662-1202

For the latest information consult www.TulsaDentalSpecialties.com Rx Only © DENTSPLY International, Inc ADPTN1 11/12

New PROTAPER NEXT features the same variable tapered performance as the original

PROTAPER, but is refi ned with:

• New unique rotary motion that further enhances PROTAPER canal-shaping effi ciency

• Proven M-Wire ® NiTi alloy for increased fl exibility and resistance to cyclic fatigue

• New rectangular cross-section design for greater strength

PROTAPER NEXT performance Or learn more

Shop for products by procedure or brand.

Re-order in one click or create separate users within your practice for purchasing control

Enroll in courses, webinars and more, with your Clinical Education credits tracked in your profi le

FIND WHAT YOU NEED FAST.

*Following your online registration, a coupon code will be emailed to you for a 20% discount off one total online order, with a maximum discount of $200

This offer is good for one use only per qualified account and may not be combined with other promotions DENTSPLY Tulsa Dental Specialties reserves the right to end the promotion at any time.

To me, it’s fun when you master a skill such as the mechanics of root canal shaping It’s fun when you have a plan and you know how to get there ProTaper NEXT (PTN) was produced with a plan

in mind: an advanced technology that gives the clinician choices, confidence, competence, safety, efficiency, technique simplicity, and yes, fun!

What makes ProTaper NEXT, next? PTN is a convergence of: 1) ProTaper Universal progressively

tapered design, 2) M-Wire® refinements for added resistance to cyclic fatigue and increased flexibility, and 3) offset axis of rotation.* The resulting NiTi “envelope of motion” allows a newfound level of shaping control With almost unanimity, these three critical distinctions have had many colleagues describing their shaping experience with words like: “sleek,” “smooth,” “enchanting,” and “magic.”

However, the best endorsement in the world is your own

The first step in successful endodontics is to decide which “tool” to use when, why, where, and how Your plan gets you to

where you’re going The resulting artistry is the signature that sets you apart Your signature becomes your reputation and

your reputation ultimately becomes your endodontic legacy

“Endodontics is a clinical game You’re supposed to have fun.” –John West, DDS, MSD

Technique Sequence I Used

to Treat These Two Patients

1 Design unimpeded smooth-walled access while fully

preserving essential ferrule

2 Brush gently on the outward stroke with ProTaper Universal

SX to remove dentin triangles and restrictive dentin when

present.

3 Prepare manual Glidepath with at least half canal length

amplitude “super loose” #10 file (confirm Glidepath with #15

file or mechanical file, if desired)

4 Float, follow, and brush on the outstroke (“let it run and paint”

are useful watchwords) with PTN X1 to length Usually 2-3

shaping waves are needed.

5 Float, follow, and brush on the outstroke with PTN X2 to

length Usually 2-3 shaping waves are needed

If X2 flutes are visibly filled with dentin: irrigate, gauge, conefit

or use a verifier to validate proper shape Follow irrigation

protocol then obturate with a vertical compaction of warm

gutta-percha technique

6 If X2 flutes are nude of dentin, proceed with X3 and larger if

occasionally needed All shapes presented were finished with

X2 or X3 Note: PTN preserves proper root canal “Flow”.

*Ruddle CJ, Machtou P, West JD, The Shaping movement:

fifth-generation technology Dent Today 2013;32(4):94-99.

PAYING SUBSCRIBERS EARN 24

CONTINUING EDUCATION CREDITS

Volume 6 Number 3 Endodontic practice 1

May/June 2013 - Volume 6 Number 3

ASSOCIATE EDITORS

Julian Webber BDS, MS, DGDP, FICD

Pierre Machtou DDS, FICD

Richard Mounce DDS

Clifford J Ruddle DDS

EDITORIAL ADVISORS

Paul Abbott BDSc, MDS, FRACDS, FPFA, FADI, FIVCD

Professor Michael A Baumann

Garry Nervo BDSc, LDS, MDSc, FRACDS, FICD, FPFA

Wilhelm Pertot DCSD, DEA, PhD

Mali Schantz-Feld Email: mali@medmarkaz.com

Tel: (727) 515-5118 ASSISTANT EDITOR

Kay Harwell Fernández Email: kay@medmarkaz.com

PRODUCTION MANAGER/CLIENT RELATIONS

Kim Murphy Email: kmurphy@medmarkaz.com

NATIONAL SALES/MARKETING MANAGER

Drew Thornley Email: drew@medmarkaz.com

Tel: (619) 459-9595 NATIONAL SALES REPRESENTATIVE

Sharon Conti Email: sharon@medmarkaz.com

Tel: (724) 496-6820 E-MEDIA MANAGER/GRAPHIC DESIGN

Greg McGuire Email: greg@medmarkaz.com

PRODUCTION ASST./SUBSCRIPTION COORDINATOR

Lauren Peyton Email: lauren@medmarkaz.com

before any part of this publication may be reproduced in any form whatsoever,

including photocopies and information retrieval systems While every care

has been taken in the preparation of this magazine, the publisher cannot be

held responsible for the accuracy of the information printed herein, or in any

consequence arising from it The views expressed herein are those of the

author(s) and not necessarily the opinion of either Endodontic Practice or the

We also have the great advantage of incorporating 3D imaging into our treatment planning for endodontic surgery, thanks to the CBCT This is an irreplaceable tool to help

us see periapical lesions not seen on films, to measure the amount of bone necessary

to drill through to access the apical portion of roots, as well as the proximity of roots to significant anatomical landmarks, such as the mental foramen and the sinuses One can use the measuring tool on the CBCT to determine the distance between an MB and ML root, for example, on mandibular molars, or the B and P root on maxillary bicuspids, as well as the direction one has to go to find these sometimes elusive roots

Also, as endodontic surgeons, we should be knowledgeable about the various bone grafting and guided tissue regeneration materials available for those cases where there is

a combination of an endodontic and periodontal lesion Of course there are cases where the teeth are just not accessible surgically, such as the second molar region, where the bone is so dense on the mandible and the patient’s lip cannot be pulled back far enough,

or those maxillary second molars that are completely in the sinuses For cases like these,

we must consider extraction/reimplantation, which has a documented success rate of over 80% when performed using modern protocol, proper case selection, and a transport medium such as Hanks Balanced Salt Solution, to maintain the viability of the PDL while the tooth is repaired extraorally

Unfortunately, as a practicing endodontist, approximately 25% of my cases are nonsurgical retreatments These cases take the most time, are the most unpredictable, and have the highest postoperative flare-up rate As a comparison, endodontic microsurgery is quicker, more predictable, especially in preserving the coronal restorations, and has a negligible flare-up rate Yes, implants are successful and popular and predictable, but in the words of a well-known periodontist and former Dean of the University of Pennsylvania Dental School, Jan Linde, “Implants replace missing teeth…

not teeth.” Endodontists are in the business of saving teeth, and therefore endodontic microsurgery should be something that all patients should be offered as a viable alternative to maintaining their own teeth

Samuel I Kratchman, DMDExton Endodontics, Inc

Exton, Pennsylvania

Endodontics in 3D

In the second in a clinical series,

Dr Richard Kahan discusses targeted endodontics 12

Effects of smear layer and debris removal with irrigation assisted

by the EndoActivator and the Endo Brush

Drs Joseph M Morelli, Mark Sakamaki, Ricardo Caicedo, and Stephen J Clark compare debris and smear layer removal from instrumented root canals after irrigation 14

Dr Nishan Odabashian: A focus on patients, colleagues, and

family

Technology, attention to detail, and knowledgeable mentors combine to help

Dr Odabashian provide a positive experience for patients

Ultradent Products, Inc.

Ultradent continues to lead the way through invention and innovation

Files to fit your technique And make apex location easy.

TiLOS ®

Don’t change your technique

Make it easier with TiLOS hand files.

©2013 Ultradent Products, Inc All Rights Reserved.

TiLOS hand files work with

your technique

No two root canal treatments are alike Your techniques

are tried and tested, and you perform them on the entire

range of cases you see every day So why not use the

hand files that make every procedure faster and easier?

Available in stainless steel and NiTi, TiLOS hand files do

just that And they’re made to work with your technique

The unique construction of the TiLOS hand files allows the apex locator to be attached to the top of the file rather than below the handle

800.552.5512

ultradent.com

Scan to watch a short video about TiLOS hand files

Case report

Detection and endodontic

treatment of a three-rooted

maxillary second premolar

Dr Imran Cassim presents a case

report detailing treatment of a

multi-rooted maxillary second premolar

Continuing his series on endodontics,

Dr Tony Druttman looks at the best

ways to measure the length of a canal

26

Continuing education

Preserving the natural smile by immediate reattachment of a fractured tooth

Drs Ramesh Bharti, Deeksha Arya, Anil Chandra, Aseem Prakash Tikku, Rakesh Yadav, and Promila Verma present two case reports detailing the reattachment of a fractured tooth fragment for the restoration of function and esthetics 28

Direct pulp capping with a bioactive dentin substitute

Dr Markus Firla discusses various solutions for pulp exposure 32

Technology

3D Apical Cork – Part 2

In the second article of this series,

Dr Wyatt Simons discusses the technologic breakthroughs that the Cork delivery device brings to obturation 36

to disintegrate different root canal sealers 41

Product insight

Barbed sutures

Dr Michael Norton discusses the barbed suture and its use in oral surgery 50

Materials & equipment . 55

Ruddle on the radar

The NITI shaping movement

Fifth generation technology 56

Aspiring endodontists

in Jamaica

46

will enjoy instantly viewable 3D volumetric images for revealing and measuring canal shapes, depths and anatomies.

Orthodontists

will benefit from high- quality pan and ceph images for optimized therapy planning.

General Practitioners

will achieve greater

diagnostic accuracy

for routine cases.

“With my Sirona 3D unit, I can see the anatomy of canals, calcification, extent of resorption, tures, and sizes of periapical radiolucencies, all of which influence treatment plans for my patients Combine that with the metal artifact reduction software that reduces distortions from metal objects,

frac-my treatment process is a lot less stressful My patients benefit from the technology and frac-my

referrals appreciate the value.” ~ Dr Kathryn Stuart, Endodontist - Fishers, Indiana

For more information, visit www.Sirona3D.com

or call Sirona at: 800.659.5977

The advantages of 2D & 3D in one comprehensive unit

ORTHOPHOS XG 3D is a hybrid system that provides clinical workflow advantages, along with the lowest possible effective dose for the patient Its 3D function provides diagnostic accuracy when you need it most: for implants, surgical procedures and volumetric imaging of the jaws, sinuses and other dental anatomy

www.facebook.com/Sirona3D

What can you tell us about your

background?

I am the oldest son, second of four

children, to parents of Christian Armenian

descent whose families ended up in the

Syrian Desert after the Armenian genocide

of 1915 My father was the oldest son of

five, of the oldest son of six My mother

was the youngest of 12, who lost her father

at 6 months of age Although my parents

had humble beginnings, my father worked

hard to improve his children’s chances of

making a better future for themselves His

first major decision towards that goal was

to leave Syria and immigrate to the U.S We

arrived in the U.S from Damascus in 1977

to N Providence, Rhode Island I was 12 I

quickly adapted to the American way of life

by first picking up the English language, and

soon becoming a Red Sox, Celtics, Bruins,

and Patriots fan We moved to California

after the 1978 snow blizzard I attended

Hollywood High School, and then I realized

my father’s dream by being the first from

our extended family to attend a university

at UCLA I continued to Tufts University

School of Dental Medicine and graduated

with a DMD degree in 1991 After 8 years

of general restorative dentistry, I went

back to school and received a certificate

of specialty and a Master’s Degree in

Endodontics from Loma Linda University

School of Dentistry (LLUSD) in 2001

under the leadership of two giants in the

field of endodontics — Drs Leif Bakland

and Mahmoud Torabinejad I have since

had a practice in Las Vegas, Nevada and

Bakersfield, California In 2008, I returned

to Glendale, California where I had

practiced general dentistry I run Glendale

MicroEndodontics (GME) and work with a

wonderful staff who all strive to provide a

most positive experience for our patients

My biggest accomplishment in my life is

my family I am married to Lilit going into

our tenth year of marriage Lilit and I are

blessed with three children, Galia, 8, Sérge,

5, and Noah, 3, who is a special-needs boy

wonder

Is your practice limited to

endodontics?

GME’s practice is limited to the specialty of

endodontics However, we try to distinguish our office by practicing microscope-aided restorative endodontics What this really means is that we recognize that endodontic treatment is only half of the treatment, and that the success of our treatment equally depends on the restorative treatment

To ensure our efforts have the maximum chance for success, we provide the permanent coronal restoration Performing the coronal restoration protects our root canal treatment and reduces the likelihood of: 1.) recontamination of the root canal system, 2.) fracture of the tooth prior to the patient having the crown placed by the general dentist, 3.) procedural accidents during the removal of the temporary and post and core placement by the general dentist, and 4.) having appropriate post size and depth as needed I also fabricate acrylic temporaries when needed, and make sure the patient returns to the referring doctor almost ready for his/her crown impressions

Why did you decide to focus on endodontics?

I owe my interest in endodontics to two very well-known endodontists from Santa Barbara, California — Drs Cliff Ruddle and Stephen Buchanan They were very influential in my becoming an endodontist,

as I am sure they have been for many like

me When I graduated dental school, the

“endo” requirement to graduate was to have treated nine canals with a minimum

of one molar tooth Needless to say, I felt inadequate with my root canal treatment abilities, and so I took several courses from Cliff and Steve, and began appreciating the complexity of root canal systems The more

I treated teeth endodontically, the more

I enjoyed the challenges that came with treating each tooth I was lucky enough to have been accepted to LLUSD’s Graduate Endodontics program (to a class of three residents) by Dr Torabinejad and the rest

of the faculty there My program laid a solid foundation for being an endodontic clinician, an educator, researcher, and a critical thinker

How long have you been practicing, and what systems do you use?

I have been a dentist for over 22 years, a restorative dentist from 1991-1999, and

an endodontist from 2001 till the present

I started my training using the Surgical Operating Microscope (SOM) in residency, and I continue to do so on 100% of the cases, from start to finish I don’t know how it is possible to perform endodontic treatment at a high level without a SOM I have heard some endodontists who don’t use the SOM say, “It’s just a tool!” I say

“You don’t know what you don’t know!” Imagine walking in a pitch dark tunnel

Dr Nishan Odabashian

A focus on patients, colleagues, and family

(Left to right) Lillia, Office Manager; Ingrid, Assistant; Elizabeth, Clinical Manager; Laura, Assistant in GME’s reception area Dr Odabashian’s children: Galia, 8, Sérge, 5, and Noah, 3 during Christmas 2012

Volume 6 Number 3 Endodontic practice 7

that has three-dimensional curves, where

the goal is to reach the end of that tunnel;

and now imagine projector lights turned

on throughout the tunnel Which method

would you prefer to reach the end of the

tunnel? Which would our patients prefer if

the tunnel is inside their tooth that needs

treatment?

Dentistry in general is a profession that

requires attention to detail at every step

of treatment One cannot pay attention to

detail at a certain part of the treatment, and

be sloppy, or even average at another part,

and still provide high quality dentistry For

high quality treatment, an endodontist has

to be detail-oriented from medical history to

dental history, to proper use of radiography

(two-dimensional, or 3D if needed), to

diagnosis to proper treatment planning

to anesthesia, to isolation to cleaning and

shaping, to obturation to restoration, to

postoperative care There is not one step

that is more important than the next to

have a successful practice that is patient

centered

In my opinion, there are a few

fundamental “musts” as far as instruments

and equipment for practicing endodontics

at a high level: The SOM, an electronic

apex locator (EAL), and more recently

a cone beam computed tomography

(CBCT) machine (when needed) There

are numerous cleaning, shaping, and

obturation systems out in the market, and

it seems that almost daily, a new file, a

new metal, or a new system is introduced,

and hailed as the next panacea These

different systems all work if used in the

manner in which they were designed To

me, these are mostly secondary What is

primary, in my opinion, is to take the time

to listen to the patients and pick up clues

about what is their chief complaint; to take

the time and diagnose the culprit tooth; to

understand that it takes time to perform

quality and successful endodontics; to

realize that the root canal system is very

complex and cannot be dumbed down to

three white stripes on a radiograph that

can be achieved in 30 minutes; and to

educate both patients and general dentists

about what is possible with meticulous

endodontic treatment

What training have you

undertaken?

As I mentioned earlier, I was fortunate to

be accepted to do my endodontic specialty

training under the well-known Mahmoud

Torabinejad, the post-graduate program director at LLUSD Dr “T,” as he is known

by his residents, is not only a program director, he is a clinician, a clinical and didactic instructor, a previous president of the American Association of Endodontists (AAE), inventor, and a father figure to his residents Dr T is the developer of Mineral Trioxide Aggregate (MTA), which has been a game-changing material that has allowed the successful repair of iatrogenic and resorptive inflammatory perforations during root canal treatment

When I began the program at LLU, Dr

Torabinejad advised me and the other two incoming residents to expect to spend 16-

18 hours a day in the program He was very demanding of his residents, demanding for them to be the best they can be For me, it was an honor to be one of his students

Who has inspired you?

Professionally, my inspiration comes from

Dr Gary Carr, an endodontist, an author, a visionary, the developer of The Digital Office (TDO) endodontic software, an inventor, and a mentor to hundreds of endodontists who are interested in performing endodontics at a high level Dr Carr has always challenged me to be the best that I can be, to always question dogma, and go beyond what is acceptable I owe Dr Carr much for being the endodontist that I have developed into

Personally, my inspiration comes from

my children They have taught me much also — patience, humility, sympathy, and understanding, among many other things I

am blessed to have them

What is the most satisfying aspect

of your practice?

I am sure I am not alone when I say that the best satisfaction for a clinician is when the result of a treatment is positive, the patient

is appreciative, and the referring dentist is glad that he/she is referring his/her patients

to you It is a great feeling when a patient writes a positive review on Yelp, Google,

or your website, out of the blue! It is also very satisfying when you receive positive comments from referring doctors about the level of treatment you are providing to their patients There is no greater professional reward for me

Professionally, what are you most proud of?

I am most proud of the fact that I have the

privilege of helping people; that I have the trust of my patients to take care of their endodontic needs I am proud that I have built a reputation in my community of being very good in my chosen profession I am proud that I don’t measure success with the amount of wealth that I amass, rather

by the number of people I help I am proud that I stand for what I believe in, and that

I am not fearful of the consequences of doing so

I am also proud of the fact that, in

a small way, I am able to contribute to dental education and organized dentistry Whether it is at the local, state, national, or even the international level, I try to volunteer

my time, knowledge, and expertise to help

my chosen profession As the saying goes,

“If you are not part of the solution, then you are part of the problem.”

I have been a part-time faculty member at LLUSD Department of Graduate Endodontics for the past 10 years I currently have the privilege of serving as the President of the California State Association of Endodontists, as well

as serving as the Chairman of the Bylaws Committee of the International Academy of Endodontics

What do you think is unique about your practice?

What I think is unique about my practice, at least in my immediate community, is that I

am not in a hurry to complete a treatment Also we use the latest technology to the patient’s advantage, whether it’s the microscope, cone beam CT, digital radiography, the Internet, or even social media If we allow patients to register online

or have them receive a text reminder of their appointment, doesn’t that make their lives easier? My endodontic practice is 50% initial treatment and 50% retreatment Unfortunately, gone are the days where endodontists are referred routine cases Generally speaking, endodontists are referred failing root canal treated teeth, severely curved or calcified teeth, teeth that have had procedural accidents, or patients who are generally either hard to manage or can’t afford treatment It takes

an office with an experienced doctor, and

a knowledgeable and understanding staff

to manage these types of referred patients, and at the same time to please the patient, the referring dentist, as well as oneself I believe that we are able to accomplish this

at Glendale MicroEndodontics

8 Endodontic practice Volume 6 Number 3

What has been your biggest

challenge?

My biggest challenge has been to

deprogram general dentists from utilizing

endodontists as providers of prescription

root canal treatments I try to get involved

in the treatment planning of a patient’s

teeth, and demonstrate that I can have

valuable input in the total outcome of the

dental treatment It is very hard to get out

of the image of a “technician” who does

root canal treatment if endodontists do not

get more involved in the decision making of

the fate of teeth

What would you have become if

you had not become a dentist?

Had I not chosen to become a dentist, I

may have become an attorney, or a math

teacher I like to teach, and I like to help

people I especially like to help the weak,

and those who have been wronged, or

taken advantage of Maybe that is why I

am always rooting for the underdog team

in sports competitions Well, unless if it is

my favorite team that is playing!

What is the future of endodontics

and dentistry?

I believe that endodontics has gone through

its golden age The specialty has challenges

that are multifactorial More than ever,

there is the competition of tooth retention

versus tooth extraction and replacement

with an implant There is competition with

general dentists performing challenging

root canal treatments that are beyond

the scope of their training or expertise

There is competition with the corporate

dental offices that have been sprouting

around the nation; ones who mostly feed

on newly graduated dentists/endodontists

by pressuring them to perform complex

or extensive treatments in short periods

of time in order to increase production;

corporations who only care about quarterly

reports and profits for their shareholders

and not for the health of their patients There

is competition with corporate-sponsored

speakers who give weekend courses that

promise to teach “Endodontics A to Z.”

There is competition with endodontists

who have conflicts of interest, promoting

their products and giving their

general-dentist audiences a false sense of simplicity

to performing root canal treatments

And, finally, there is competition with

endodontists delivering mediocre or

average care to their patients for different

TDO Clinical Forum The Surgical Operating Microscope, without which I don’t think I could practice endodontics Traveling

Cars Learning Teaching

To contact Dr Odabashian, email nishan@glendalemicroendodontics.com.

reasons Unless all endodontists get involved in teaching at the dental schools;

unless we are more active in study clubs and contribute to treatment planning;

unless we make high level of care a top priority, and use the available technology;

unless we take the necessary time and address the complex root canal anatomy, and put the patient’s needs first; unless

we get the message across to general dentists and patients, alike, that root canal treatment can be painless, predictable, yet requires skill and patience; and finally, unless we as endodontists understand that

a successful tooth is much more important than a successful root canal treatment, and stop decoupling the endodontic treatment from the restorative treatment, it is going

to be very challenging going forward and maintaining endodontics in the high esteem

it has enjoyed in the past 50 years I am hopeful that this will happen I will do my part to educate my referring doctors and

my patients I am hopeful I can maintain a high standard of care of the specialty that

I love

What are your top tips for maintaining a successful practice?

The best advice I can give for maintaining a successful practice is listen to your patients

Treat them with genuine care Make sure you communicate with your referring doctors and colleagues Be involved in the community Educate general dentists and your patients Always stay ahead of the curve

What advice would you give to budding endodontists?

The best advice that I can give to budding endodontists is to have a mission statement that represents who they are, and keep striving to reach and maintain it Keep their personal costs low at the outset of their career Surround themselves with quality people, whether they are referring doctors

or staff people Practice with their patients’ best interests at heart Make sure and learn things that were not taught in dental/endo school, such as the business aspects of running a practice and ergonomics Make quality their priority; people will notice Put patients first, and success will follow Try to distinguish themselves from others Have

an online presence Show concern for their patients, and mean it

What are your hobbies, and what

do you do in your spare time?

My favorite thing to do besides spending time with my family and performing endodontic treatment is playing bridge Whether it is social bridge or tournament-style bridge, I forget about the rest of the world when I am playing it One day, I would like to travel the world, and play at national and international tournaments

I also like to watch sporting events especially live Every chance I get, I take

my kids, five nephews, and two nieces

to professional basketball, baseball, and hockey games I want to one day attend the French Open, Wimbledon, the Australian Open, and the U.S Open tennis tournaments in the same year!

The Odabashian family: Wife, Lilit, Dr Odabashian, Galia, Sérge, and Noah

EP

Penetrate Better

Than Needle Irrigation

235 Ascot Parkway | Cuyahoga Falls, OH 44223

Tel USA & Canada 800.221.3046 | 330.916.8800 | coltene.com

PATENT PENDING

• Distributes and ultrasonically activates sodium hypochlorite to increase debridement of lateral canals and isthmuses

• Ratcheting syringe permits controlled delivery

of 0.2 ml of solution with each audible click

Benefits of Continuous Ultrasonic Irrigation:

• Removes significantly more debris from narrow isthmuses better than conventional needle irrigation*

• Significantly increases the penetration of irrigation solutions into lateral canals**

Ultrasonic Irrigator

*Adcock et al, J.Endod 2011; 37 (4) **Castelo-Baz et al, J Endod 2012; 38 (5)

Ultradent Products, Inc.

Following graduation from Loma Linda University in 1974 and starting his own dental practice, Dr Fischer realized that rapid, profound hemostasis was imperative for quality tissue management and operative dentistry Because there were

no products on the market that predictably controlled bleeding and sulcular fluid, he decided to develop one Using his natural-born insight, determination, and willingness

to work after hours, Dr Fischer began experimenting with different chemistries, even drawing his own blood to test their hemostatic effects Within a short time,

Dr Fischer came up with what are now Ultradent’s flagship tissue management products, Astringedent®, and later ViscoStat®

Business grew rapidly, and over the next 35 years, Ultradent expanded from

a home operation to a foot facility, which presently houses more than 1,000 employees Ultradent

220,000-square-is the most vertically integrated dental company in the world — manufacturing over 90% of its products (which includes over 500 materials, devices, and instruments) at its South Jordan, Utah, headquarters Ultradent prides itself on its technologically advanced way of doing things In fact, with the exception of the auto industry, Ultradent uses more robotics than any other company west of the Mississippi

Instead of saving on production costs through outsourcing, which many U.S manufacturers do, Dr Fischer firmly believes in the opposite He says, “The more one outsources, the more one ships production, or R&D, or other aspects to other parts of the world, the more one loses touch with what has made them who they are.”

Ultradent continues to lead the way through invention and innovation The company holds numerous U.S patents (both granted and pending) and continues

to expand internationally into many parts

of Europe, Asia, and South America

Beyond its humble beginnings in tissue management products, Ultradent’s product family now includes world-class adhesives, composites, tooth whitening systems, and more Ultradent has also expanded its reach to orthodontics, serving as the parent company of Opal Orthodontics Its South Jordan headquarters even boasts

an onsite orthodontic clinic

Although Ultradent strives to offer the latest and greatest in technology, Dr

Fischer’s passion for a minimally invasive approach to dentistry has and will continue

to guide the development of every new product created in the future

Ultradent Endodontics

Like the story behind the conception of Astringedent, Ultradent’s endodontic solutions were born out of necessity Dr

Fischer noticed a need for a successful endodontic protocol that could be done with the minimally invasive criteria he

is so passionate about The result was Endo-Eze® AET™ (Anatomic Endodontic Technology) classic stainless steel files, which utilize a reciprocating motion

These uniquely designed files proved very effective in following the natural canal shape and minimizing apical transportation and ledging This new approach paved the way to the array of endodontic products Ultradent offers the clinician today

Building on the success of the Eze AET classic stainless steel files, Ultradent developed the world’s first hydrophilic and self-priming resin sealer, EndoREZ® canal sealer When paired with the NaviTip® — with its flexible, stainless steel cannula, designed to easily navigate curved canals — EndoREZ canal sealer offers easier obturation in less time, has the same radiopacity as the gutta percha, and consistently delivers a complete, thorough seal It’s also worth noting that the NaviTip was the first tip on the market capable of safely delivering irrigants to the apex

Endo-Building on the success of the AET files, Ultradent created the Endo-Eze®

AET™ TiLOS® system — a hybrid of stainless steel and NiTi files optimized for the company’s 30-degree reciprocating handpiece, Endo-Eze® Arios® The award-winning TiLOS system features a user-friendly, straightforward instrumentation sequence, and comes in autoclavable, preconfigured packs The RediPack offers tools to address each canal according to its unique anatomy and is equipped to treat 90% of endodontic cases TiLOS’ ribbon-shaped, ovoid handles also provide more comfort and ease of grip to the clinician than ever before The Endo-Eze Arios’ reciprocating motion facilitates rapid, complete, uniform instrumentation of all the walls in an irregularly shaped canal, while preserving more tooth structure than traditional rotary systems The pairing of Arios with the TiLOS files thus accomplishes a “milling” action, instead of

a “drilling” action, while also eliminating file breakage

Ultradent’s vision to “Improve Oral Health Globally” through minimally invasive dentistry and to design products as an

answer to the call of clinicians worldwide continues to shape the success of the company in this, its 35th year in the industry

To learn more about the endodontic products mentioned or the wide array of additional endodontic solutions provided

by Ultradent, please visit ultradent.com, or call 800-552-5512

This information was provided by Ultradent Products, Inc.

EP

J Morita Veraviewepocs ® 3De

KODAK 9000 3D Extraoral Imaging System

Turns out there’s a correlation between quality of care and quality of life TDO software is now

seamlessly integrated with both the J Morita and Kodak CBCT units, and both endodontists and

patients alike couldn’t be more pleased For patients, TDO CBCT means being able to review

scans chairside in the comfort of your office For you, it means scans are saved to each patient’s

chart, and a comprehensive TDO CBCT report is generated within just three minutes—a function

no other software provides Find out how TDO can save you time, money, and most importantly,

headaches Switch to the only endodontic software that is truly CBCT integrated—TDO

“With TDO’s CBCT integration, all of my volumes are acquired and saved within

each patient’s chart, so they can be pulled up effortlessly without searching I

am able to review these volumes with my patients chair-side immediately after

acquisition I could not imagine using CBCT imaging without TDO integration It

saves a tremendous amount of time.”

— Dr Robert Corr, Colorado Springs, CO Show specials include 0% interest financing, free website setup &

custom web designs for only $1500

Visit us at the AAE! Booth #431

This series of case discussions highlights

the use of cone beam computed

tomography (CBCT) in clinical endodontics,

and how it is used to enhance diagnosis,

decision-making, treatment planning, and

the treatment itself

In the first article in the series, which

appeared in Endodontic Practice US,

September/October 2012, Volume 5, No

5, I explained the reason why periapical

and periradicular lesions might not show

on conventional 2D radiographs This

would explain the relatively poor scores of

55-77% for sensitivity in diagnosing such

lesions (Bohay, et al., 2000; Estrela, et al.,

2008) The accuracy of CBCT elevating

sensitivity to 91% in one study (de

Paula-Silva, et al., 2009) means that as well as

providing the ability to detect disease

and find “hidden lesions,” it can be used

accurately to confirm the lack of disease

This is particularly useful in endodontic

retreatment cases showing signs of failure

In many cases, the endodontic treatment

objectives have been satisfactorily

achieved in all but missed anatomy, with

a lesion only associated with an untreated

canal In a situation where presence or lack

of disease cannot be absolutely confirmed,

it would be necessary to retreat the entire

canal system With CBCT, a lesion can be

accurately traced to its source, possibly

a single root of a multi-rooted tooth;

therefore, sometimes treatment can be

targeted at the diseased root leaving the

other canals intact

This principle of Targeted Endodontics

has benefits in time, cost to the patient,

simplicity, and reducing the chances of

iatrogenic damage to sound roots during retreatment for no benefit

Clinical details

The patient was a 57-year-old male with

no relevant medical history, complaining of mild pain associated with his post-crowned and root-filled LL4 The tooth had been treated and restored many years previously and had an unblemished history until this point The porcelain-bonded crown was esthetically and functionally satisfactory with a good marginal seal Clinically, there was some minor tenderness to percussion from both an occlusal and buccal direction without any tenderness to palpation The surrounding periodontal condition was satisfactory and soft tissues healthy

The periapical radiograph (Figure 1) revealed a post-crown restoration with

an associated root filling just sealing the apical 3 mm of the root The post was relatively wide with a post-crown ratio of 2:1 Beyond the post and down to the root filling was a void of approximately 4-5 mm Both the post and the root filling were asymmetrically positioned in the root, suggesting some form of anatomical deviation in the distal segment of the root

A small apical lesion was associated with distal part of the root apex

Also noted was a satisfactory root filling in the LL5 A periapical lesion was present at the mesial root of the LL6 that had been recently root treated Both the LL5 and LL6 were found to be clinically asymptomatic

The limited volume 4 cm x 4 cm CBCT

scan confirmed the presence of a small lesion at the distal part of the root apex of the LL4 (Figure 2) The coronal slice (Figure 3) confirms the periodontal ligament space beneath the root filling is intact The axial slice (Figures 4A and 4B) reveals the source

of the lesion to be a separate untreated distolingual canal Vertucci (1978) quotes a frequency of 74% for two separate canals

in a lower first premolar

Importantly in this case, although deficient in terms of a gap between the post and apical extent of the root filling, there were no signs of apical pathology associated with the filled mesial canal (Figure 3)

The position of the mental foramen, which is an important consideration

in surgical planning, was found to be inconsequential (Figure 2)

Treatment considerations

If we take the perspective given to us

by the periapical radiograph alone, the best treatment option here is limited to the removal of the crown, post removal, retreatment of the existing root-filled canal (due to the gap and possibility of apical pathology), along with a search for any further canal(s) in the distal root segment This would entail significant time and expense in deconstruction, temporization, and an eventual new post-crown, as well

as the risk of root fracture on post removal and weakening tooth structure hunting for further canal anatomy

The surgical option runs the risk of mental nerve damage and leaving large

Endodontics in 3D

In the second in a clinical series, Dr Richard Kahan discusses targeted endodontics

Figure 1: Preoperative periapical radiograph Distal radiolucency associated with the LL4 Mesial radiolucency

at LL6

Richard Kahan, BDS, MSc (Lond), LDS RCS

(Eng), is a specialist endodontist working

in Harley Street, London, and the former

Director of Endodontic Courses at UCL

Eastman CPD He has lectured widely on endodontics

and technology and has recently set up the Academy

of Advanced Endodontics to teach the fundamentals

of endodontics to GDPs through extended mentoring

within his practice With 5 years’ experience of

endodontic CBCT using the Morita Veraviewepochs

3D, his clinic has become a referral center for complex

cases used by both endodontists and GDPs For more

information visit www.endodontics.co.uk.

Figure 2: CBCT saggital slice – confirming distal positioning of the periapical lesion at LL4 The mental foramen is below the LL5

The periapical lesion at the LL6 relates to recent treatment

Volume 6 Number 3 Endodontic practice 13

segments of contaminated canal untreated,

with only the apical retro seals blocking

these off from the periapical tissues Once

these inevitably leak, the lesion will return

With the view that CBCT confers, the

fact that the unsatisfactory-looking root

filling can be confirmed as not contributing

to the pathological process liberates us

from the necessity to involve the mesial

canal and its post in the treatment plan

Treatment can be targeted precisely at

the cause of the pathology, which is an

untreated distal canal This allows us a

faster, safer, and cheaper plan, guided by

axial CBCT slices acting as a positioning

system, to locate and treat the distal canal

only

Treatment

Although faster and potentially safer,

the treatment process was not without

technical difficulty as lining up a cavity

through a crown and cast core is fraught

with possibilities of missing the distal canal

orifice and perforating the root

The safest means of guiding a bore

hole through the crown to the distal canal

orifice would be using a drilling jig built

on a 3D printed model of the tooth, in a

similar way to guided implant placement

However, this was not feasible as it was

impossible to produce the accurate

stereolithographic files necessary for a 3D

printing with the metallic artifact and beam

hardening around the post-crown

In practice, I use a “Heads-Up display”

(HUD) means of working (Figure 5), with positioning in the tooth constantly being checked against landmarks on enlarged scan slices Through this technique, I was able to successfully drill down to the distal canal orifice (Figure 6) and check that I had correctly entered the root canal (Figure 7)

Endodontic treatment was completed in a single session following chemomechanical preparation using Hedstrom files and a hybrid ProTaper (Dentsply) and GT® hand file protocol (Dentsply Tulsa Dental Specialties), together with heated sodium hypochlorite and EDTA irrigation Gutta percha and Roth’s sealer cement obturation was carried out using System B™ (SybronEndo) vertical heat condensation with a Calamus®

backfill The orifice was countersunk with a Gates-Glidden No 5 bur, and a permanent amalgam alloy post core was placed through the access cavity (Figures 8 and 9)

Follow-up

The patient was checked the next day, and no ill effects were reported One week later, he reported that the area was comfortable, and that the dull ache in the lower left quadrant had resolved A further appointment for a review radiograph was scheduled for 6 months

Summary

An elegant and simple endodontic treatment plan can sometimes become accessible if accurate diagnostic information is made available In this case, CBCT was used

to target the pathology and allow us to ignore an expensive and potentially risky alternative that would have no impact on the disease process

REfEREncEs

Vertucci F J Root canal morphology of mandibular

premolars J Am Dent Assoc 1978;97(1):47-50

Bohay R N The sensitivity, specificity, and reliability

of radiographic periapical diagnosis of posterior

teeth Oral Surg Oral Med Oral Pathol Oral Radiol

Endod 2000;89(5):639-642.

Estrela C, Bueno MR, Leles CR, Azevedo B, Azevedo

JR Accuracy of cone beam computed tomography and panoramic and periapical radiography

for detection of apical periodontitis J Endod

2008;34(3):273-279

de Paula-Silva FW, Wu MK, Leonardo MR, da Silva LA, Wesselink PR Accuracy of periapical radiography and cone-beam computed tomography scans in diagnosing apical periodontitis using

histopathological findings as a gold standard J

Endod 2009;35(7):1009-1012.

Figure 3: CBCT coronal slice - The

periodontal ligament space below the

root filled canal is intact and healthy

Figures 4A and 4B: CBCT axial slices – The cross-sectional shape of the root of the LL4 is a figure eight with an untreated canal in a distolingual position Figure 5: Super-large clinical Heads-Up Display (HUD)

Figure 6: Successful location of the distolingual

canal orifice in the LL4 Figure 7: Check periapical confirming location and negotiation of untreated distolingual canal in

the LL4

Figure 8: View of the coronal gutta percha in the distolingual canal of the LL4

Figure 9: Postoperative periapical radiograph

EP

Cutting of dentin during root canal

therapy produces a debris layer that

coats the dentin This has been termed

“smear layer.” The purpose of this study

was to compare smear layer or debris

removal from instrumented root canals

using assisted and unassisted irrigation

methods Eighty single canal teeth were

decoronated and hand instrumented to

a No 20 K-file Instrumentation was then

completed with 04 rotary K3 (SybronEndo)

files to a Master Apical File (MAF) of size

No 40 One ml of 5.25% NaOCl was used

to irrigate canals between file sizes in all

groups Samples were divided into four

groups After instrumentation, all canals

were irrigated with 1 ml of 17% EDTA for

1 minute followed by a final rinse of 3 ml

of 5.25% NaOCl This was accomplished

using a 3cc syringe and Monoject 27

gauge irrigation needle Group one was

designated the control group In the three

experimental groups, irrigation was also

assisted with either the Endo Brush®(Roeko)

in standard low-speed handpiece (Group

2), the EndoActivator® (Group 3) [Dentsply Tulsa Dental Specialties], or the Endo Brush® in Sonicare® toothbrush (Group 4)

Samples were scored for remaining debris using digital photography and Adobe®

Photoshop® software These samples were submitted for statistical analysis Four samples from each group were randomly selected and submitted for SEM analysis

The EndoActivator group was found to be somewhat more efficient, but there was no statistical significance between the groups when comparing debris or quantity of smear layer removal

Introduction

The smear layer has been a subject of interest to investigators since the 1970s (Figure 1) There is lack of agreement to the significance of the smear layer and whether

it should be removed There is further lack

of agreement regarding the significance of smear layer on instrumentation, obturation, and clinical outcome Conflicting results have been obtained in numerous in vitro studies Orstavik and Haapasalo1 showed

in an in vitro study that removal of smear layer with resultant patent dentinal tubules decreased time necessary for disinfection

of the dentin with intracanal medicaments

Other studies have shown better adhesion

of obturation materials to canal walls after smear layer removal.2,3 Other studies have shown no effect of smear layer removal on microleakage of root canals with various

sealers and obturation techniques.4-7 Timpawat, et al.,8 showed conflicting results This study reported that removal

of the smear layer has adverse effects

on microleakage of filled root canals Despite conflicting studies, Torabinejad

in a review article,9 states that “One may deem it prudent to remove the initially created smear layer in infected root canals and to allow penetration of intracanal medicaments into the dentinal tubules of these teeth.”

Various methods have been used to remove smear layer McComb and Smith were the first investigators that showed REDTA (a commercially available solution

of EDTA) can remove smear layer.10 man reported that REDTA alone removes the inorganic layer but does not remove the organic constituent.11 In later studies, Goldman, et al., as well as Yamada, et al., and Baumgartner and Mader showed that alternating the use of EDTA and NaOCI is

Gold-an effective method of removing the smear layer.12-14 Other studies have tested various mixtures and concentrations of chemicals and application times.16-17 Products con-tinue to come to the market claiming the ability to enhance smear layer removal The Endo Brush (Figures 2 and 3) has been de-veloped to mechanically assist the clean-ing of the smear layer within the root ca-nal It is a synthetic brush thin enough to fit into a root canal and can be attached

to the handle of a Sonicare toothbrush or

Effects of smear layer and debris removal with irrigation assisted by the EndoActivator and the Endo Brush: A comparison with unassisted standard syringe irrigation with 5.25% NaOCl and 17% EDTA

Drs Joseph M Morelli, Mark Sakamaki, Ricardo Caicedo, and Stephen J Clark compare debris and smear layer removal from instrumented root canals after irrigation

Figure 1: SEM of dentin at 500X wth smear layer (left) and SEM of dentin at 500X after smear layer removal showing less debris and patent dentin tubules

Joseph Morelli received his DDS degree

from Loyola University and his Endodontic

certificate from Tufts University He is currently

an Associate Professor of Endodontics at the

University of Louisville and a Diplomate of

American Board of Endodontics.

Mark Sakamaki received his DDS degree

from the University of Colorado and his

Endodontic certificate from the University of

Louisville in 2008 He is currently in private

practice in Floyds Knobs, Indiana.

Ricardo Caicedo received his Dr Odont

degree from the Colegio Odontologico

Colombiana in Bogota, Colombia and his

endodontic certificate from the University

of Louisville He is currently an Associate

Professor of Endodontics at the University of

Louisville.

Stephen Clark received his DMD degree and

endodontic certificate from the University

of Kentucky and is currently a Professor of

Endodontics at the University of Louisville

He is a Diplomate of the American Board of

Endodontics.

Volume 6 Number 3 Endodontic practice 15

standard low-speed handpiece When

ac-tivated, the brush rotates within the canal

during irrigation The EndoActivator (Figure

4) uses a flexible, noncutting polymer tip

at-tached to a special handpiece that vibrates

the tip up to 10,000 cpm, thus agitating the

irrigation solution Manufacturers of both

of these products claim enhanced smear

layer removal Solaiman, et al.,18 compared

a brush covered needle (NaviTip® FX®,

Ul-tradent) to irrigation with a standard

nee-dle without the brush cover They found

cleaner coronal thirds of instrumented root

canals compared to the control group, but

no significant differences for the middle

and apical third of the canals Uroz-Torres,

et al.,19 evaluated the EndoActivator

sys-tem in removing smear layer after rotary

instrumentation, with and without a final

flush of 17% EDTA in the coronal, middle,

and apical thirds of canals They found no

significant differences The purpose of the

present study was to compare debris and

smear layer removal from instrumented

root canals after irrigation with 5.25%

Na-OCI and 17% EDTA, either unassisted or

assisted by the Endo Brush in a standard

low-speed handpiece, Endo Brush in the

Sonicare toothbrush, or with the

EndoActi-vator

Methods and Materials: This study

followed the method previously used by

Crumpton, et al.20 Eighty single canal

anterior and premolar human teeth were

stored in 1:10 dilution of 5.25% NaOCI

Teeth were decoronated, and the root length standardized at 15 mm Working length was established with a No 10 K-file placed in the canal until just visible

at the apex and 1 mm subtracted from this length All teeth were hand instrumented

to a size 20 K-file, then instrumented to working length with rotary instrumentation using K3 0.04 taper files in a crown-down technique to a MAF size No 40 One ml

of 5.25% NaOCI was used to irrigate each canal between files

The samples were then divided into four groups of 20 teeth:

Group 1: (control) Samples were irrigated

with 1 ml of 17% EDTA for 1 minute followed by a final rinse of 3 ml of 5.25%

NaOCI

Group 2: Samples were irrigated with 1 ml

of 17% EDTA with mechanical assistance

by the Endo Brush in a standard speed handpiece for 1 minute followed by

slow-a finslow-al rinse of 3 ml of 5.25% Nslow-aOCI When used, the Endo Brush was placed into the canal to within 2 mm of the working length and activated A pumping motion was used to move the Endo Brush in 2-3 mm vertical strokes for 60 seconds

Group 3: Samples were irrigated with 1 ml

of 17% EDTA with mechanical assistance

by the EndoActivator for 1 minute followed

by a final rinse of 3 ml of 5.25% NaOCI When used, the EndoActivator was placed into the canal to within 2 mm of the working length, and run at 10,000 cpm

A pumping motion was used to move the EndoActivator in 2-3 mm vertical strokes for 60 seconds

Group 4: Samples were irrigated with 1 ml

of 17% EDTA with mechanical assistance

by the Endo Brush in a Sonicare electric toothbrush followed by a final rinse of 3

ml of 5.25% NaOCI When used, the Endo Brush was placed into the canal to within

2 mm of the working length and activated

A pumping motion was used to move the Endo Brush in 2-3 mm vertical strokes for

60 seconds

Teeth were longitudinally grooved with

a diamond disk and split buccolingually A digital photograph was taken of the split tooth using a Canon EOS 10D camera with Canon Macrolens EF 100mm Magnification Ration: 1:1 (Figures 5 and 6) This image was imported into Adobe Photoshop 7.0 and magnified X10 using the zoom tool Canal area and debris were outlined using the Lasso tool The

Figure 2: Roeko Endo Brush as supplied from

THE FUTURE HAS RETURNED.

THE ORIGINAL PLASTIC ENDODONTIC ROTARY FINISHING FILE IS BACK.

MANUFACTURER DIRECT

MADE IN THE U.S.A

Figure 4: The EndoActivator, Advanced Endodontics

histogram function was used to calculate

the percentage of debris remaining in the

coronal, middle, and apical thirds

Four samples from each group were

randomly selected and prepared for SEM

analysis A representative sample from

the coronal, middle, and apical thirds of

each root was examined Smear layer

was scored according to criteria used by

Torabinejad, et al.21 The three evaluators

were two full-time endodontic faculty and

one endodontic resident

Results

A Linear Univariate Analysis was done to

test for a significant difference in means

among the four test groups and among

the three evaluators (Figure 7) There

was no significant difference among all

groups interacted with all the evaluators

Because of the small sample size for the

photomicrographs, no statistical analysis

was performed The evaluators’ scoring

indicated a similar number of clean canals

in the coronal and middle sections for all

Figures 5-6: Canon EOS 10D camera and set up to photograph tooth specimens

test groups With all techniques, clean or moderately clean canals were seen in the coronal and middle third of the specimens

High levels of debris were seen in the apical thirds in all groups Scores of 3 (high level of debris) were most common in apical third specimens for all groups Representative photomicrographs are shown in Figure 9

Discussion

This study compared smear layer and debris removal from instrumented root canals using assisted and unassisted irrigation methods Although there was no statistical significance, the EndoActivator tended to produce cleaner canals (Figure 8) Perhaps with a larger sample size, there would have been some significance

Evaluation of the photomicrographs indicated that all methods produced similar results and were capable of rendering clean or moderately clean canals All photomicrographs showed some remaining debris even in sections judged as clean with little or none Unlike the Solaiman

study in which no significant difference was found between coronal, middle, and apical thirds, this study found most debris in the apical third for all methods This study did not compare coronal, middle, and apical segments of the canals However, all methods appeared to be more effective

in the coronal and middle segments of the instrumented canals A future study could test for significance at different canal levels

e Type III Sum of Squares df Mean Square F Sig Partial Eta

Volume 6 Number 3 Endodontic practice 17

Conclusions

There was no significant difference among

test groups

Assisted irrigation with the

EndoActivator appeared to produce the

cleaner instrumented canals although the

differences were not significant It would

seem that the addition of sonic aggitation

to standard irrigation with syringe does

increase the efficiency of removing debris

and smear layer from instrumented

canals Further studies are necessary to

find methods of improvng the cleanliness

of instrumented canals at the apical third

level as current methods produce the least

desirable results at this level

Figures 9A-9D: A Group 1, apical

third, 1000X B Group 2, apical

third, 1000X C Group 3, apical

third, 750X D Group 4, middle

third, 750X

REfEREncEs

1 Orstavik D, Haapasalo M Disinfection by endodontic irrigants and dressings of experimentally infected dentinal tubules

Endod Dent Traumatol 1990;6(4):142-149.

2 Tidmarsh BG Acid-cleansed and resin-sealed root canals J

Endod 1978;4(4):117-121.

3 White RR, Goldman M, Lin PS The influence of the smeared layer upon dentinal tubule penetration by plastic filling

materials J Endod 1984;10(12):558-562.

4 Evans JT, Simon JH Evaluation of the apical seal produced

by injected thermoplasticized Gutta-percha in the absence of

smear layer and root canal sealer J Endod 1986;12(3):101-107.

5 Saunders WP, Saunders EM Influence of smear layer and the coronal leakage of Thermafil and laterally condensed

gutta-percha root fillings with a glass ionomer sealer J Endod

1994;20(4):155-158.

6 Madison S, Krell KV Comparison of ethylenediamine tetraacetic acid and sodium hypochlorite on the apical seal of

endodontically treated teeth J Endod 1984;10(10):499-503.

7 Timpawat S, Sripanaratanakul S Apical sealing ability of

glass ionomer sealer with and without smear layer J Endod

1998;24(5):343-345.

8 Timpawat S, Vongsavan N, Messer HH Effect of removal

of the smear layer on apical microleakage J Endod

2001;27(5):351-353.

9 Torabinejad M, Handysides R, Khademi AA, Bakland LK

Clinical implications of the smear layer in endodontics: a

review Oral Surg Oral Med Oral Pathol Oral Radiol Endod

14 Baumgartner JC, Mader CL A scanning electron

microscopic evaluation of four root canal irrigation regimens J

aqueous solutions Int Endod J 2003;36(6):411-415.

17 Teixeira CS, Felippe MC, Felippe WT The effect of application time of EDTA and NaOCI on intracanal smear layer

removal: an SEM analysis Int Endod J 2005;38(5):285-290.

18 Al-Hadlaq SM, Al-Turaiki SA, Al-Sulami U, Saad AY Efficacy

of a new brush-covered irrigation needle in removing root

canal debris: a scanning electron microscopic study J Endod

2006;32(12):1181-1184.

19 Uroz-Torres D, Gonzalez- Rodriquez MP, Ferrer-Luque

CM Effectiveness of the EndoActivator System in removing

the smear layer after root canal instrumentation J Endod

21 Torabinejad M, Khademi AA, Babagoli J, Cho Y, Johnson

WB, Bozhilov K, Kim J, Shabahang S A new solution for the

removal of the smear layer J Endod 2003;29(3):170-175.

“Endodontology is concerned with the

form, function and health of, injuries to, and

disease of the dental pulp and periradicular

region, their prevention and treatment.”

—European Society of Endodontology,

2006

When the pulp is subject to continued

stimulation from microorganisms, the

inevitable result is its irreversible destruction

and complete breakdown Anaerobic

bacteria may then exploit the enclosed

environment of the pulp chamber and

proliferate Consequently, the inflammatory

process may spread beyond the confines

of the pulp chamber and into the periapical

tissues

The main aim of treatment is the

ability to control the intracanal infection

Root canal therapy is performed with the

intention of thorough mechanical and

chemical debridement of the entire pulp

space followed by complete obturation

with an inert filling material

Success is measured in terms of

clinical signs, symptoms, and radiographic

evidence of healing

Case history

A 30-year-old medically fit female attended

complaining of low grade dull ache localized

to the UR6 After a thorough history

and examination, a diagnosis of apical

periodontitis of the UR6 was made (Table

1) Treatment options were discussed,

following which treatment entailing

prevention, restorative, and endodontic

care was undertaken The UR6 required

a conventional root canal, and using the

AAE’s American Endodontic Case Difficulty

Assessment Form, it was deemed to be of

minimal to moderate difficulty Informed

consent was gained, explaining the

benefits, risks, and alternative options for

procedure and treatment The prognosis

was assessed to be around 80-85%

due to the radiographic evidence of a

periradiculuar lesion (Figure 1)

Treatment was performed in one visit (Figini, et al., 2007) under rubber dam and anesthesia, which helped in managing the patient’s anxiety The access cavity was prepared prior to placement of the rubber dam The aim was to achieve straightline access and to preserve tooth tissue (Qualtrough, et al., 2005) Further refinement was performed using an ultrasonic scaler and a round bur on a long neck to remove dentin overlying the canal orifices Magnification (2.5% Orascoptic loupes with illumination) and a DG16 probe were used to find the MB2 canal, but in this case, only three canals were located (Figure 2)

Disinfection was performed using a small gauge needle (30) and 3% sodium

hypochlorite (NaOCl) Coronal third shaping was then performed with copious irrigation throughout using Gates-Glidden burs An electronic apex locator (Root ZX®,

J Morita Corp.) was used to determine working length (Simon, et al., 2009), and canal patency was obtained using a size

10 stainless steel K-file Apical preparation was then performed using a size 30, 06 taper ProFile® nickel-titanium rotary instrument (Dentsply Maillefer) lubricated with EDTA (Glyde™, Dentsply)

A strict irrigating regime was employed throughout the cleaning and shaping phase of treatment (Table 2) The technique used to obturate the three canals was cold lateral condensation followed by thermo compaction of gutta percha (GP) using a gutta condenser and Sealapex™

Maxillary molar endodontic case presentation

Dr Rahul Bose presents the case report that won him the acclaimed title of Young Dentist Endodontic

Award 2012

Figure 1: Pre-endodontic treatment radiograph

Rahul Bose, BDS, is a general dental practitioner,

practicing in Oxford and London, England.

Figure 2: Prepared access cavity

Young Dentist Endodontic Award, sponsored by the The Harley Street Centre for Endodontics, invited young dentists from the UK who graduated in the last 3 years to submit a case report of their best endodontic treatment so far.

Volume 6 Number 3 Endodontic practice 19

(SybronEndo) [Figures 3 and 4] Coronal

seal was then obtained using Vitrebond™

(3M) to seal the GP followed by a Fuji IX™

Core (GC) and a hybrid composite (3m

Z250)

A postoperative periapical of the

UR6 showed the final outcome was good

(Figure 5), and over a period of 12 months,

the periradiculuar lesion had healed (Figure

6), and the patient was symptom free

Discussion

The aim of the treatment provided to the

patient was based on integrating the best

evidence with clinical knowledge and

patient preferences The following areas

warrant further discussion regarding the

treatment provided:

1 Why was 3% NaOCl used rather than

any other irrigant?

Evidence available suggests that NaOCl is

the “gold standard” irrigant to use in root

canal treatment in comparison to

chlorhex-idine, iodine, and other products (Eliyas,

Briggs, Porter, 2010) When used in

com-bination with 15-17% EDTA, both inorganic

and organic substances can be removed

effectively The EDTA also enhances the

antimicrobial effects of the NaOCl due to

removal of the smear layer (Hülsmann,

Heckendorff, Lennon, 2003)

Concentra-tions of 0.5%-5.25% NaOCl have been

shown to have the same antibacterial fect (Byström, Sundqvist, 1983) However, NaOCl at greater concentrations dissolves vital and necrotic tissue faster, but in turn carries the potential risk of extrusion from the apical foramen, resulting in rapid, pain-ful, and serious inflammatory response Three percent is a good compromise, and its use is also recommended by endodon-tist Tony Hoskinson There is also evidence

ef-to suggest that heating NaOCl ef-to tures of 45-60°C significantly increases the effectiveness of the solution (Sirtes, et al., 2005) However, no facility existed within the practice to heat the solution while per-forming the treatment

tempera-2 Are apex locaters more effective than radiographs for working length measurements?

Modern apex locators are shown to

be more accurate in working length determination than a radiograph (Pagavino, Pace, Baccetti, 1998; McDonald, 1992) They work using different frequencies,

Figure 3: Obturation Figure 4: Obturation

Figure 5: Postoperative radiograph Figure 6: One-year follow-up radiograph

Others claim a closed tip, but a microscope may reveal a much different story

The RINN Max-i-Probe tip is welded closed to protect your patient from fluids expressing past the apex

“ the Max-i-Probe removed significantly more bacteria the unique side vent of these safety-ended needles produces upward turbulence that enhances complete cleaning of root canals.“

— Journal of Endodontics, Vol.33, No 6, June 2007

M AX - I - P ROBE®

ENDODONTIC/PERIODONTAL IRRIGATION PROBES

FREE SAMPLE AT WWW R INN C ORP COM

‘Closed-end’

generic probe Max-i-Probe

The irrigating probe confirmed

THE BEST

in the Journal of Endodontics.

20 Endodontic practice Volume 6 Number 3

determining the ratio between the

different electric potentials proportional

to each impedance These devices are

not root canal length “calculators,” rather

they are apical area locators (foramen

or constriction) Radiography is still an

important adjunct to the use of a locator

However, it has been confirmed to be less

reliable than an apex locator as the foramen

may not end at the radiographic apex

Although, it may be seen as good

practice to take working length/dry run

radiographs, the British Endodontic Society

(BES) does not state it to be mandatory

Reducing the amount of additional

radiographs taken results in a reduced

exposure of ionizing radiation

3 What are the benefits of using

nickel-titanium instruments?

The advantages of using rotary instruments

include:

• More effective debris removal coronally

• Centered in canal – much less likely to ledge

• Predetermined taper

• Predictable shape

• QuickerStudies show that there are fewer procedural errors and better shaping ability of the nickel-titanium instruments

in comparison to stainless steel K-files

However, there are few reports to show any significant differences between the two instruments (Cheung, Liu, 2009)

4 Why was no extra coronal restoration provided?

Firstly, studies have shown that the quality

of the coronal seal has a significant effect

on the outcome of endodontic treatment (Saunders, Saunders, 1994) Leakage can

be reduced by the placement of adhesive restoration placed over the gutta percha

permanent filling (Qualtrough, et al., 2005)

In this case, the marginal ridges of the UR6 were intact following treatment This suggested the tooth was less liable

to fracture and more likely to withstand

“wedging” forces developed during function (Hansen, 1988) Evidence suggests that root canal therapy does not change the quality of dentin, except some moisture loss (increase in brittleness), and

it is thought that weakening of the tooth is more as a result of tooth tissue loss (Ingle, Bakland, Baumgartner, 2008) Therefore an extracoronal restoration was not provided

5 How is the tooth going to be monitored for success?

According to the BES (2006), the RCT should be assessed at least after 1 year The following findings indicate a favorable outcome:

• Absence of pain/swelling/sinus tract

• No loss of function

• Radiological evidence of normal periodontal ligament space around the tooth

Conclusion

The case demonstrates a predictable new technique (for a newly qualified dentist), integrating best evidence with clinical knowledge and patient preference, demonstrating the ability to efficiently and effectively provide appropriate and adequate care Upon a yearly review, the tooth had responded favorably

to treatment, and the patient had no symptoms or complaints The periapical radiograph taken to visualize the DB canal and assess healing shows healing of the apical radiolucency, and the DB canal was filled satisfactorily (Figure 6)

REfEREncEs

Byström A, Sundqvist G Bacteriologic evaluation of the

effect of 0.5 sodium hypochlorite in endodontic therapy

Oral Surg Oral Med Oral Pathol 1983;55(3):307-12.

Cheung GS, Liu CS A retrospective study of

endodontic treatment outcome between nickel-titanium

rotary and stainless steel hand filing techniques J

Endod 2009;35(7):938-943.

Eliyas S, Briggs PF, Porter RW Antimicrobial irrigants

in endodontic therapy: 1 Root canal disinfection Dent

Update 2010;37(6):390-392,395-397.

European Society of Endodontology Quality guidelines

for endodontic treatment: consensus report of the

European Society of Endodontology Int Endod J

2006;39(12):921-930.

Figini L, Lodi G, Gorni F, Gagliani M Single versus multiple visits for endodontic treatment of permanent

teeth Cochrane Database Syst Rev 2007;17(4).

Hansen EK In vivo cusp fracture of endodontically treated premolars restored with MOD amalgam or MOD

resin fillings Dent Mater 1988;4(4):169-173.

Hülsmann M, Heckendorff M, Lennon A Chelating agents in root canal treatment: mode of action and

indications for their use Int Endod J

2003;36(12):810-830.

Ingle JI, Bakland LK, Baumgartner JC Ingle’s

endodontics 6th ed Hamilton, Ontario: BC Decker;

2008.

McDonald NJ The electronic determination of working

length Dent Clin North Am 1992;36(2):293-307.

Pagavino G, Pace R, Baccetti T A SEM study of in

vivo accuracy of the Root ZX electronic apex locator J

Endod 1998;24(6):438-441.

Qualtrough AJE, Satterthwaite JD,Morrow LA, Brunton

PA Principles of operative dentistry Oxford UK:

Blackwell Munksgaard; 2005.

Simon S, Machtou P, Adams N, Tomson P, Lumley P

Apical limit and working length in endodontics Dent

Update 2009;36(3):146-150,153.

Sirtes G, Waltimo T, Schaetzle M, Zehnder M The effects of temperature on sodium hypochlorite short-term stability, pulp dissolution capacity, and

antimicrobial efficacy J Endod 2005;31(9):669-671.

Saunders WP, Saunders EM Coronal leakage as a

cause of failure in root-canal therapy: a review Endod

Dent Traumatol 1994;10(3):105-108.

Irrigation regime:

Irrigate copiously and frequently with room temperature 3% NaOCl during mechanical

preparation

Every third irrigation, EDTA used

After shaping complete:

Two minutes with NaOCl – GP cones were tried for length with NaOCl in situ This

allows for displacement of NaOCl solution into lateral canals (mechanical activation)

One minute EDTA + U/s followed by NaOCl to remove smear layer

Final flush saline

Throughout the procedure, a small gauge needle (30) was placed loosely in the canal,

which allowed the correct application of the irrigant and hydrodynamics For the apical

third, the needle was bent 2-3 mm shorter than the working length in order to prevent

extrusion of the irrigant through the apex

EP

“The ASI Endodontic carts are a great convenience This space

saving design allows me to be organized and efficient with only one

foot control and without all of the cords draped over my counters.”

– Dr Kelly Jones

The Cart, With Only One Foot Control

The versatility of ASI’s custom integrated cart system

allows for infinite positioning of the cart

to easily maneuver within close reach

during procedures and then out of patient

view after procedures Adding a monitor

mount creates an intimate environment for

both patient education and clinical use.

Side Delivery

An ASI cart positioned at the doctor’s

dominant side requires the least amount of

tasking movements during a procedure and

works efficiently with microscope dentistry

Foot Control Placement

The foot control tubing of an ASI system can

be run underneath the floor through a conduit

from the junction box to the patient dental

chair The end result creates easy access to

the foot control without tubing running

across the floor

The Junction Box

In addition to attractively concealing the standard

connections of compressed air, suction and electricity,

ASI’s unique in-wall junction box allows computer

connections such as video, USB, network and other

IT connections throughout the office to be easily

organized and safely hidden from view.

1-800-566-9953 • asimedical.net

Successful endodontic therapy is

dependent on the quartet of shaping,

disinfection, three-dimensional sealing

of the root canal system, and a coronal

seal, forming an effective barrier between

the root canal system and the oral cavity

(Schilder, 1974; Cantatore, Berutti,

Castellucci, 2009; Kirkevand,

Horsted-Bindslev, 2002)

The possibility of finding aberrant

canal configurations is always present and

higher in premolars and molars (Cantatore,

Berutti, Castellucci, 2009)

The use of magnification and

illumination, an astute assessment of

parallel and angled radiographs, as well as

the pulp chamber floor map, can help in

reducing the risk of missing a canal during

endodontic treatment

Clinicians should be careful when

treating maxillary premolars because of the

extreme variability of their anatomy, and

the risk of missing a canal in these teeth

is always present The maxillary second

premolar usually has one or two canals,

and one or two roots, but the incidence of

three root canals is very rare and has been

reported to be 0.3% (Pecora, et al., 1992)

and 0.66% (Kartal, Özçelik, Çimilli, 1998)

Radiographic appearances that would

indicate more than one canal are:

• The “fast break” rule suggested

by Yoshioka, et al (2004), which is a

sudden narrowing of the canal system on

a parallel radiograph

• When the mesiodistal width of a

maxillary premolar tooth at midroot level

is equal to or greater than the mesiodistal

width of the crown, on a parallel radiograph,

then the tooth most likely has three roots

suggested by Sieraski, et al., (1989)

Radiographic examination showed

a deep interproximal filling close to the pulp chamber (Figures 1A, 1B and 2) It was also noted that the mesiodistal width

of the tooth at midroot level was equal to the mesiodistal width of the crown of the tooth, and that the pulp chamber suddenly decreased in width, indicating the presence

of three canals on this upper left second premolar (Figure 1B)

Following anesthesia and rubber dam placement, the access cavity was made using a 0.16 tapered diamond crown preparation bur because of the depth and narrow width of the pulp chamber (Figure 3) Though there was no periapical radiolucency discernable on X-ray, pus oozed out the palatal canal, and it was flushed with 3% sodium hypochlorite

The access cavity was then modified

to a T-shape using the Start-X™ 1 (Dentsply) ultrasonic tip (Figure 4) The Start-X 3 tip was then used to refine the straightline access to the two buccal canals (Figure 5) Working lengths were determined using

an electronic apex locator, and a working length X-ray was taken (Figure 6)

Preparation of the canals was initiated after ensuring a size 10 K-file was loose in all canals Then glide paths were prepared using Pathfiles™ 1, 2, and 3 (Dentsply) The canals were then shaped using the WaveOne® Primary file (25/08) in the WaveOne motor (Dentsply)

A 3% solution of sodium hypochlorite was used for irrigation and agitated with the EndoActivator (Dentsply) [Figure 7] Once shaping was completed, the canals were irrigated with 17% EDTA

to remove the smear layer and agitated with the EndoActivator® (Dentsply) The canals were dried, and there was still exudate present, so a dressing of calcium hydroxide was placed in the canals and the access cavity sealed with DuoTemp™ light cured temporary filling material (Colténe Whaledent®) The patient was scheduled a second appointment 2 weeks later

At the second visit, the patient reported

Detection and endodontic treatment of a

three-rooted maxillary second premolar

Dr Imran Cassim presents a case report detailing treatment of a multi-rooted maxillary second premolar

Figure 2: Angled preoperative X-ray

Imran Cassim obtained his BDS degree in 1999

from University of Witwatersrand, South Africa He

completed a postgraduate diploma in endodontics

with distinction from University of Pretoria in 2009

He is currently completing an MSc in endodontics at

University of Pretoria and is in practice in Durban, South

Africa He is a visiting lecturer in the Postgraduate

Department of Endodontics at University of Pretoria

He writes, lectures, and conducts workshops on

endodontic topics.

Figure 4: The Start-X 1 ultrasonic tip used

to refine access and modify to a T-shape Figure 5: The straightline access to all the canals after

troughing with the Start-X 1 and 3 ultrasonic tipsFigure 3: A view of the initial access cavity

Figures 1A and 1B: Parallel preoperative X-ray showing the sudden narrowing of the pulp chamber (white arrow) and the mesiodistal width of the midroot almost equal to the mesiodistal width of the crown

Use for Access Refinement, Retreatment, and Restorative

procedures There’s a BUC tip ready to accomplish a

multitude of endodontic treatment challenges.

Call Obtura Spartan Endodontics today at (800) 344-1321

or visit us online at www.obtura.com to place an order.

Obturation Ultrasonics Surgery Irrigation Diagnostics

*Free ground shipping for all orders placed online.

©2013 Obtura Spartan Endodontics *Free ground shipping for all orders placed online with a shipping address in the United States or Canada See instructions for use For professional use only Obtura Spartan Endodontics – 2260 Wendt Street, Algonquin, IL 60102

24 Endodontic practice Volume 6 Number 3

that all symptoms had subsided Following

anesthesia and rubber dam application,

the temporary filling was removed The

canals were flooded with 17% EDTA and

agitated with the EndoActivator to remove

the calcium hydroxide dressing The canals

were gauged with a size 25 K-file (Dentsply

Maillefer), and it was snug at the apex of

all three canals The GuttaCore® (Dentsply

Tulsa Dental Specialties) size 25 verifier

file was placed in each canal to verify easy

placement and passage of the GuttaCore

obturator The canals were irrigated with

3% sodium hypochlorite, the irrigant

agitated, and then the canals dried

A small amount of AH Plus® sealer

(Dentsply) was placed with a paper point

in the coronal third of the mesiobuccal

canal; a paper point trimmed to orifice

level was placed in the distobuccal canal,

and then, the GuttaCore obturator was

placed in the dedicated heating oven, and

the mesiobuccal canal was obturated The

obturator was sectioned off at orifice level

using a Thermacut® bur (Dentsply Maillefer)

and then a Machtou plugger (Dentsply

Maillefer) used to apply condensation

pressure to the obturator at orifice level The

excess gutta percha over the distobuccal

orifice was removed by engaging the

paper point with a size 40 Hedstroem file

(Dentsply Maillefer) and removing it from

the canal, thereby allowing easy placement

of the subsequent GuttaCore obturator in

the distobuccal canal

The distobuccal and palatal canals

were obturated in the same manner as

described for the first canal, but the handle

of the carrier was removed by bending it

to either side of the canal wall Figure 8 shows the pulp chamber after all canals were obturated The access cavity was etched and restored with Spectrum® SDR®

and TPH® spectrum composite (Dentsply), and the patient was referred back to his dentist for an overlay to protect the cusps A follow-up X-ray at 1 year revealed radiographically healthy periradicular tissues (Figure 10), and the patient was reminded that a coronal restoration with cuspal coverage would be needed

The Start-X 1 and 3 ultrasonic tips (Dentsply) facilitate this step with conservative removal of dentin in the narrow confines of the premolar pulp chamber, and the non-end cutting tip of the Start-X 1 ultrasonic tip helps to leave the pulp chamber floor map intact and reduces the risk of perforating the pulp floor The occlusal can also be reduced to facilitate visibility and access, and to the orifices of the canals

The PathFiles series of nickel-titanium

files allowed for rapid preparation of a glide path while minimizing hand fatigue The preparation of a glide path reduces change

to the natural curvature of the canal with subsequent mechanical shaping of the canal by reciprocation (Bertutti, et al., 2012)

The GuttaCore carrier based tion technique allows for the movement

obtura-of warm gutta percha three-dimensionally into all areas of the properly shaped root canal system (Gutmann, 2011) A meticulous assessment of multiple angled radiographs, the use of magnification, illumination, adequate access cavity preparation, and the awareness of possible anatomic variations can aid the clinician

in the treatment of multi-rooted maxillary second premolars

Figure 6: Working length X-ray showing three separate canals Figure 7: EndoActivator (Dentsply) in use for agitation of irrigants Figure 8: View of pulp chamber after obturation

REfEREncEs

Berutti E, Paolino DS, Chiandussi G, et al Root canal anatomy preservation of WaveOne reciprocating files with or without

glide path J Endod 2012;38:101-104.

Cantatore G, Berutti E, Castellucci A Missed anatomy:

frequency and clinical impact Endod Topics 2009;15:3-31 Gutmann JL The future of root canal obturation Dent Today

2011;30(11):128,130-1.

Holland GR, Walton RE Diagnosis and treatment planning In:

Torabinejad M, Walton RE, eds Endodontics Principles and Practice, 4th ed St Louis, MO: Saunders Elsevier; 2009:68-93.

Kartal N, Özçelik B, Çimilli H Root canal morphology of

maxillary premolars J Endod 1998;24(6):417-419.

Kirkevang LL, Horsted-Bindslev P Technical aspects

oftreatment in relation to treatment outcome Endod Topics

2002;2:89-102.

Pecora JD, Sousa Neto MD, Saquy PC, Woelfel JB In vitro

study of root canal anatomy of maxillary second premolars Braz Dent J 1992;3:81-85.

Schilder H Cleaning and shaping the root canal Dent Clin North Am 1974;18:269-96.

Sieraski SM, Taylor GN, Kohn RA Identification and endodontic

management of three-canalled maxillary premolars J Endod

1989;15(1):29-32.

Vier-Pelisser FV, Dummer PMH, Bryant S, Marca C, So´ MVR, Figueiredo JAP The anatomy of the root canal system of three-rooted maxillary premolars analyzed using high-resolution

computed tomography Int Endod J 2010;43:356-362.

Yoshioka T, Villegas JC, Kobayashi C, Suda H Radiographic evaluation of root canal multiplicity in mandibular first premolar

J Endod 2004;30:73-74.

Figures 9A, 9B and 9C: The different angled postoperative X-rays; note the S-shaped curvature of the DB root and material adaptation to the

canal walls Figure 10: A 1-year follow-up X-ray reveals healthy periapical tissue

EP

For more information contact Axis|SybronEndo

at 800.346.3636 or visit sybronendo.com

tfadaptive.com/enjoythejourney

You’re in control>TF Adaptive is designed to work with our ElementsTM Adaptive Motion

Technology, which allows the TF Adaptive file to self-adjust to intra-canal torsional forces

In other words — rotary when you want it and reciprocation when you need it

Keep it simple > An intuitive, color-coded system designed for efficiency and ease of use.

Peace of mind > TF Adaptive is built on the success of the Classic TF design and includes

the same advanced Twisted File technology

Trusted by

Gary Glassman, D.D.S.

Endodontist Toronto, Canada

®

One of the main reasons endodontically

treated teeth fail is because the canals

have not been cleaned adequately All too

often, cases are referred for retreatment

where the root fillings are short on the

radiograph, and on retreating the tooth, the

correct working length has been achieved

(Figures 1A and 1B) Long root fillings have

also been associated with endodontic

failures, although this is usually due to

inadequate debridement and disinfection,

rather than overextension of the root

filling through the root apex (Figure 2)

Adequate canal preparation does not just

involve reaching the apex with a file of a

certain size: the canal has to be cleaned

thoroughly in all its dimensions, but I’ll

discuss this further in later issues

Determining the working length is

an evolutionary process starting with

the preoperative radiograph As I have

discussed in previous articles, a good

quality radiograph has to be taken using

the paralleling technique with the aid of

an aiming device/image receptor holder

This should give an undistorted image

of the crown and the roots When using

film, a reasonably accurate estimate of

the working length can be achieved by

measuring the length with a hand file

against the film With digital techniques,

the software should be available in the

program, which can measure the length,

irrespective of whether the canal is curved

or straight

Some canals are divergent from

the long axis of the tooth and will look

foreshortened on a radiograph This is

often the case with the palatal roots of

upper molars but can affect other teeth as

well (Figure 3)

It is therefore important to measure the working length accurately and to maintain working length during preparation There are three methods for determining length:

diagnostic length radiographs, electronic apex locators, and the consistent drying point,1 and during canal preparation, either two out of the three or all three methods can be used to give optimal results

The apical extent of preparation

There are differing opinions regarding the apical extent of the preparation The average distance between the apical constriction and the radiographic apex is 0.5 to 1.0 mm, but can be considerably more The end point of preparation should

be the minor apical diameter or apical constriction (Figure 4) The difficulty is that the position of this junction can be quite variable and by preparing the canal

to an arbitrary end point, an apical plug of infected material may be left, which could result in failure Also it is not unusual for the root tip to have multiple apical foramina, which may exacerbate the problem further (Figures 5A and 5B)

The alternative approach is to maintain apical patency, and rather than to create

an apical stop, a tapered preparation is developed, which relies on the developed geometry to create resistance form for the obturating material Apical patency

is created and maintained by inserting a small file approximately 1 mm through the apical constriction to ensure that an apical plug of dentin/infected material does not

Top ten tips:

Tip number 7 – To determine length

Continuing his series on endodontics, Dr Tony Druttman looks at the best ways to measure the length of a canal

Tony Druttman, MSc, BChD, BSc, is an

endodontist working in central London He

is also a part-time teacher at the Eastman

Dental Institute, University of London, and

lectures in the UK and abroad.

Figure 1A: Preoperative radiograph of a failed root treatment on tooth 25

accumulate during preparation

Sometimes this is not possible as the canal appears to have a ledge at the apex, which has been created naturally rather than iatrogenically This is due to the natural anatomy of the root, and it may

be impossible to bypass the ledge In this situation, the canal has to be prepared as far possible (Figure 6)

Radiographic technique

The traditional way of determining working length is by taking radiographs with files

in the canals Where canals overlap, as

in the mesial canals of lower molars, the radiograph can be taken with an increased horizontal angulation to separate the canals

If the leading edge of the image receptor

is angled away from the mesiodistal axis, the buccal canal is the more distal, and the palatal or lingual canal is the more mesial (Figure 7) A Hedstrom file can be used in one canal and a K-file in the other

to distinguish between the canals The radiographic technique is useful to cross check against an apex locator reading

Figure 1B: Postoperative radiograph of the retreated 25 at the correct working length

Figure 2: Lack of correct working length deter-mination has caused overextension of the root filling and left the patient with a parasthesia of the lower lip

One of the main reasons endodontically

treated teeth fail is because the canals

have not been cleaned adequately All too

often, cases are referred for retreatment

where the root fillings are short on the

radiograph, and on retreating the tooth, the

correct working length has been achieved

(Figures 1A and 1B) Long root fillings have

also been associated with endodontic

failures, although this is usually due to

inadequate debridement and disinfection,

rather than overextension of the root

filling through the root apex (Figure 2)

Adequate canal preparation does not just

involve reaching the apex with a file of a

certain size: the canal has to be cleaned

thoroughly in all its dimensions, but I’ll

discuss this further in later issues

Determining the working length is

an evolutionary process starting with

the preoperative radiograph As I have

discussed in previous articles, a good

quality radiograph has to be taken using

the paralleling technique with the aid of

an aiming device/image receptor holder

This should give an undistorted image

of the crown and the roots When using

film, a reasonably accurate estimate of

the working length can be achieved by

measuring the length with a hand file

against the film With digital techniques,

the software should be available in the

program, which can measure the length,

irrespective of whether the canal is curved

or straight

Some canals are divergent from

the long axis of the tooth and will look

foreshortened on a radiograph This is

often the case with the palatal roots of

upper molars but can affect other teeth as

well (Figure 3)

It is therefore important to measure the working length accurately and to maintain working length during preparation There are three methods for determining length:

diagnostic length radiographs, electronic apex locators, and the consistent drying point,1 and during canal preparation, either two out of the three or all three methods can be used to give optimal results

The apical extent of preparation

There are differing opinions regarding the apical extent of the preparation The average distance between the apical constriction and the radiographic apex is 0.5 to 1.0 mm, but can be considerably more The end point of preparation should

be the minor apical diameter or apical constriction (Figure 4) The difficulty is that the position of this junction can be quite variable and by preparing the canal

to an arbitrary end point, an apical plug of infected material may be left, which could result in failure Also it is not unusual for the root tip to have multiple apical foramina, which may exacerbate the problem further (Figures 5A and 5B)

The alternative approach is to maintain apical patency, and rather than to create

an apical stop, a tapered preparation is developed, which relies on the developed geometry to create resistance form for the obturating material Apical patency

is created and maintained by inserting a small file approximately 1 mm through the apical constriction to ensure that an apical plug of dentin/infected material does not

Top ten tips:

Tip number 7 – To determine length

Continuing his series on endodontics, Dr Tony Druttman looks at the best ways to measure the length of a canal

Tony Druttman, MSc, BChD, BSc, is an

endodontist working in central London He

is also a part-time teacher at the Eastman

Dental Institute, University of London, and

lectures in the UK and abroad.

Figure 1A: Preoperative radiograph of a failed root treatment on tooth 25

accumulate during preparation

Sometimes this is not possible as the canal appears to have a ledge at the apex, which has been created naturally rather than iatrogenically This is due to the natural anatomy of the root, and it may

be impossible to bypass the ledge In this situation, the canal has to be prepared as far possible (Figure 6)

Radiographic technique

The traditional way of determining working length is by taking radiographs with files

in the canals Where canals overlap, as

in the mesial canals of lower molars, the radiograph can be taken with an increased horizontal angulation to separate the canals

If the leading edge of the image receptor

is angled away from the mesiodistal axis, the buccal canal is the more distal, and the palatal or lingual canal is the more mesial (Figure 7) A Hedstrom file can be used in one canal and a K-file in the other

to distinguish between the canals The radiographic technique is useful to cross check against an apex locator reading

Figure 1B: Postoperative radiograph of the retreated 25 at the correct working length

Figure 2: Lack of correct working length deter-mination has caused overextension of the root filling and left the patient with a parasthesia of the lower lip

Volume 6 Number 3 Endodontic practice 27

Figure 5A: Endodontic treatment of tooth No 30 carried out to an arbitrarily determined working length

Figure 5B: Endodontic retreatment of tooth in Figure 5A

demonstrating the presence of an apical delta Figure 6: Teeth Nos 28 and 29 with blocked apices and extruded sealer Figure 7: Diagnostic length radiograph of tooth No 14 The mb1 canal is to the right; the mb2 is to the left in the

mesiobuccal root

Figure 8: Endo Ray Figure 9: Morita Root ZX

Positioning the image receptor can be

difficult with the rubber dam in place Using

a positioning device, such as the Endo

Ray for use with film, ensures consistently

accurate result (Figure 8)

Electronic apex locators

These are some of the most useful

instruments that we have in endodontics

and produce very reliable and reproducible

readings Recent research quotes 97%

reliability.2 We now have sixth-generation

units, which are designed to cope with any

fluid in the canal The convention is to take

the “zero reading” length and reduce 0.5

mm to get the working length I find my

unit – a Morita Root ZX – gives me such

reliable readings that I rarely need to take

diagnostic length radiographs (Figure 9)

Readings should be taken throughout the

process of canal enlargement as the canal

length can change especially in curved

canals

Figure 10: Paper point showing a consistent point of bleeding

Consistent drying point technique

This is a simple technique, which determines the junction between where there is a blood supply, for example, the periodontal membrane, and where there

is not, the prepared root canal It can only work when patency filing is used The canal

is dried and a paper point inserted that will pass beyond this junction The length of the dry part of the paper point is measured

to confirm the working length (Figure 10)

The technique is repeated three or four times to ensure that a consistent result is obtained The canal length should also be confirmed by other means before the root filling is placed

Dento-legal obligations

In our ever more litigious society, endodontics is one of the specialities that attracts the greatest amount of activity from our defense organizations It is vital that the length of every canal is measured

2 Plotino G, Grande NM, Brigante L, Lesti B, Somma

F Ex vivo accuracy of three electronic apex locators:

Root ZX, Elements Diagnostic Unit and Apex Locator

and ProPex Int Endod J 2006;39:408–414.

Clarification:

In the January/February 2013 issue of Endodontic

Practice US, Dr Druttman’s Endodontics in Focus article titled “Tip number 5 — Access cavities and canal location,” inadvertently omitted the reference for an article written by Drs Paul Krasner and

Henry Rankow from The Journal of Endodontics

On pages 28 and 29, the information in the list of basic rules about canal position, numbered 1-6 should have ended with the following reference: Krasner P, Rankow H Anatomy of the pulp

chamber floor J Endod 2004;Jan;30(1):5-16

Figure 3: Lower first molar with two distal roots, with the

same working length for each distal canal Figure 4: Landmarks at the root apex

and recorded, whether by radiograph or electronic apex locator.EP