By: Dr. Syed Mukhtar-un- Nisar Andrabi

Assistant Professor, Conservative Dentistry & Endodontics,

Dr. Z. A. Dental College, A. M. U. Aligarh.

Basics Of Root Canal Treatment

Lecture Outline

1) INTRODUCTION / DEFINITION

2) ROOT CANAL ANATOMY/ CONFIGURATION

1) ROOT CANAL MICROBIOLOGY

3) ROOT CANAL TREATMENT (Step by Step Procedure)

1) Indications

2) Contraindications

3) Access Opening

4) Shaping And Cleaning

5) Irrigation

6) Obturation

4) POST ENDODONTIC RESTORATIONS

5) CASE DESCRIPTIONS

Endodontics

The branch of dentistry that is concerned with the

morphology, physiology, and pathology of the

dental pulp and periradicular tissues.

Its study and practice encompass the basic and

clinical sciences, including biology of the normal

pulp; the etiology, diagnosis, prevention, and

treatment of diseases and injuries of the pulp; and

associated periradicular conditions.

(Mosby's Dental Dictionary, 2nd edition. © 2008 Elsevier, Inc.)

Tooth Anatomy

Root Canal System- 3D

Canal Configurations

Oral microorganisms

Pulp and Periapical Disease

The ultimate goal of the endodontic treatment

is either to prevent the development of apical

periodontitis or, in cases where the disease is

already present, to create adequate conditions

for periradicular tissue healing.

The rationale for endodontic treatment is to

eradicate the occurring infection and/or

prevent reinfection.

Microbiology of Root Canal

Infections

Endodontic

infections are

poly-microbial

“mixed type” of

infections.

Common Endodontic Pathogens

Treponema denticola most commonly isolated from

Porphyromonas endodontalis primary root canal infections

Enterococcus faecalis (isolated from failed root canals)

Bacteroidetes

Streptococcus species

Porphyromonas gingivalis

Actinomyces radicidentis

Candida albicans

Root canal treatment Debridement

Disinfection

Obturation

Restoration (Post endodontic restoration)

When do we do root canal treatment?

INDICATION

Factors to be considered before endodontic

therapy?

1) General health of the patient

2) Strategic value of the tooth

3) Root canal anatomy of the tooth

4) Structural integrity of the tooth

5) Restorability of the tooth

6) Periodontal status of the tooth

A non-strategic tooth

A tooth with insufficient periodontal support

A non-restorable tooth

A tooth with a vertical fracture

A tooth with massive internal or external resorption

A tooth that has a canal unsuitable for instrumentation or

surgery (e.g. dentinal sclerosis, sharp dilacerations etc.)

When we don’t do root canal therapy?

CONTRAINDICATIONS

How do we do root canal therapy?

TREATMENT PROTOCOL

Step by step procedures:

Diagnosis

Preparation for the treatment

Endodontic access

Biomechanical preparation (Shaping & Cleaning)

Obturation

Post endodontic restoration

Diagnosis

1.Assemble facts

Chief complaint

Medical & Dental history Subjective sym.

History of the present condition

2. Screen & interpret the assembled clues (Examination)

3. Differential Diagnosis

4. Operational or working diagnosis (Final diagnosis)

Preparation for the Treatment

Infection Control.

Sterilization of the equipment

Personal barrier equipment

Follow CDC &OSHA guidelines

Informed Consent. The procedure and prognosis must be described.

Alternatives to the recommended treatment must be presented, along with their

respective prognoses.

Foreseeable risks and material risks must be described.

Patients must have the opportunity to have questions answered

Local anesthesia administration.

Rubber dam isolation

Endodontic Access

The objectives of access cavity

preparation:

1) To remove all caries,

2) To conserve sound tooth structure,

3) To completely unroof the pulp chamber,

4) To remove all coronal pulp tissue (vital or necrotic),

5) To locate all root canal orifices,

6) To achieve straight- or direct-line access to the apical foramen or to

the initial curvature of the canal, and

7) To establish restorative margins to minimize marginal leakage of the

restored tooth.

Phases of access cavity

preparation Penetration phase

Enlargement phase

Finishing and flaring phase

Endodontic Access – armamentarium

Orifice Location

Krasner and Rankow (J Endod 2004; 30(1):5)

a study involving 500 pulp chambers found that the

cementoenamel junction (CEJ) was the most important

anatomic landmark for determining the location of pulp

chambers and root canal orifices. study demonstrated the

existence of a specific and consistent anatomy of the pulp

chamber floor.

proposed nine guidelines, or laws, of pulp chamber anatomy

to help clinicians determine the number and location of

orifices on the chamber floor

Orifice Location Law of centrality: the floor of the pulp chamber is always located in the center of the tooth at the level of the CEJ (Figs. 1–3).

Law of concentricity: the walls of the pulp chamber are always concentric to the external surface of the tooth at the level of the CEJ (Figs. 1–3).

Law of the CEJ: the CEJ is the most consistent, repeatable landmark for locating the position of the pulp chamber.

1 2

3

First law of symmetry: Except for the maxillary molars, canal orifices

are equidistant from a line drawn in a mesiodistal direction

through the centre of the pulp chamber floor.

Second law of symmetry: Except for the maxillary molars, canal

orifices lie on a line perpendicular to a line drawn in a mesiodistal

direction across the centre of the pulp chamber floor.

Orifice Location

Law of color change: The pulp chamber floor is always darker in

color than the walls.

First law of orifice location: The orifices of the root canals are

always located at the junction of the walls and the floor.

Second law of orifice location: The orifices of the root canals

are always located at the angles in the floor–wall junction.

Third law of orifice location: The orifices of the root canals are

always located at the terminus of the roots’ developmental fusion

lines.

Orifice Location

Law of color change 1st Law of Orifice Location

2nd Law of Orifice Location 3rd Law of Orifice Location

How useful are the laws?

Knowledge of the law of centrality will help prevent crown perforations in a lateral direction.

The law of concentricity will help the clinician to extend his access properly.

The law of color change provides guidance to determine when the access is complete. Proper access is complete only when the entire pulp-chamber floor can be visualized.

The Law of Orifice Locations 1 and 2 can be used to identify the number and position of the root canal orifices of the tooth

The laws of symmetry 1 and 2, color change, orifice locations 1 and 2 can be applied to any tooth.

Anterior Access Cavity Preparations

Anterior Access Cavity Preparations:

Inadequate access

preparation. The

lingual shoulder

was

not removed, and

incisal extension is

incomplete. The file

has begun

to deviate from the

canal in the apical

region, creating a

ledge.

Correct refined

access preparation

with straight line

access to the apical

foramen

Mandibular

central/lateral

incisors

Posterior Access Cavity Preparations-

Maxillary molar

Posterior Access Cavity Preparations-

Maxillary first molar

Posterior Access Cavity Preparations-

Maxillary first molar

Posterior Access Cavity Preparations

Mandibular molar

Shaping & Cleaning

Debridement & Disinfection

Root Canal Therapy

Mechanical

Instrumentation Irrigation

Intra-canal

medication

R.C. Filling

Microbial Control Phase

Biomechanical preparation-

(Shaping & Cleaning)

It is development of a logical cavity preparation that is specific for the anatomy of each root(Raidenget et al JOE 1998)

Biomechanical preparation refers to the controlled removal of dentin and root canal contents by manipulation of root canal instruments and materials.

Shaping refers to specific root canal form with particular design and objectives.

Cleaning refers to removal of all root canal contents before and during shaping which includes substrates, microflora, bacterial products, food, caries etc.

Objectives of Biomechanical

preparation

Biological

to eliminate microorganisms from the root canal system.

to remove pulp tissue that may support microbial growth,

to avoid forcing debris beyond the apical foramen which may sustain inflammation.

Mechanical Develop Continuously

tapering funnel from the access cavity to apical foramen

The root canal preparation should maintain the path of the original canal

The apical foramen should remain in its original position

The apical opening should be kept as small as practical

Endodontic

instruments

Manually

operated

Engine-driven

NiTi rotary

instruments

Ultrasonic

instruments

K-files

K-reamers

Headstroms

Broaches

Latch type rotary instruments

Reciprocating instruments

Self adjusting files

K-file

Reamer

Techniques For Preparing Root Canals:

Apico coronal

Standardized technique

Step back

Roane balanced force technique

Corono apical

Step down

Crown down pressure less

Hybrid technique

Canal preparation-current protocol

Straight -line access

Canal exploration

Coronal pre-flaring/ pre-enlargement (orifice shaping)

Length determination

Apical third preparation.

Canal preparation-current protocol

Apical stop: Apical seat Open apex

Endodontic Irrigation

Root Canal Irrigation

Rationale: Mechanical instrumentation leaves significant

portion of root canals wall untouched. (Peters et. Al 2001)

Irrigation solutions are required to eradicate microbiota,

Objectives Of Irrigation

(1) flushing out debris,

(2) lubricating the canal, mechanical objective

(3) tissue dissolving

(4) Antimicrobial action- biologic objective

Most Commonly Used Irrigants

Hydrogen peroxide (3-30%)

Sodium hypochlorite (0.5-5.25%)

Iodine potassium iodide (2-5%)

Chlorhexidine (0.2-2%)

EDTA

Biopure MTAD

Factors Influencing Efficacy of

Irrigation

Diameter of the irrigating needle

Depth of the irrigating needle engaged in root canal

Size of enlarged root canal (radius of tube)

Viscosity of the irrigating solution (surface tension)

Velocity of the irrigating solution at the tip of the needle

Orientation of the bevel of the needle

Temperature

CFD Model of

Apical vapor lock

effect

An effective irrigant must reach

the apex, create a current and

remove particles

Irrigation Accidents

Obturation

Root Canal Obturation

Three-dimensional obturation of the radicular space is essential to

long-term success.

The canal system should be sealed apically, coronally, and laterally.

Obturation is a reflection of biomechanical preparation.

“canals poorly obturated are often poorly prepared and thus have a poor

prognosis”.

In 1924 Hatton indicated, “Perhaps there is no technical operation in

dentistry or surgery where so much depends on the conscientious adherence

to high ideals as that of pulp canal filling.”

Timing of Obturation

Factors determining the readiness of a canal for

obturation:

Patient’s signs and symptoms

Ability to dry the canal

In general, obturation can be performed after cleaning

and shaping procedures when the canal can be dried

and the patient is asymptomatic.

Obturation of a canal that cannot be dried

is contraindicated.

Timing of Obturation

The Root Canal Filling

Core materials Sealers

Silver Cones

Gutta-Percha

Activ GP

Resilon

Zinc Oxide and Eugenol

Calcium Hydroxide Sealers (CRCS, Apexit and Apexit Plus)

Glass Ionomer Sealers (Ketac-Endo)

Resin (AH-26, AH Plus, EndoREZ, Epiphany)

Silicone Sealers (RoekoSeal)

Bioceramic

Core materials

Activ GP

AH Plus sealer

Size #30 standard gutta-percha

points exhibiting #.02,

#.04, and #.06 tapers.

The Ideal Root Canal Filling

Length,

Taper,

Density,

Level of gutta-percha and

sealer removal coronally

Adequate provisional

restoration

Lateral Compaction

Post Endodontic Restoration

Post Endodontic Restoration

Restoration of endodontically treated teeth is always a

challenge in many ways because of the various

differences in the physical properties of the vital and the

non-vital teeth.

Most often such teeth require the placement of posts and

core build ups to achieve proper resistance and retention

form.

How are endodontically treated teeth

different? Altered physical characteristics: Moisture : Helfer et al Collagen: Rivera et al Access opening: 14% reduction in strength

Altered esthetic characteristics Altered light refraction Degradation of pulp tissue Medicaments, fillings

Loss of proprioception

Treated cases

Case 1

Pre-operative view of the patient.

Pre- operative radiograph

Endodontic treatment started under rubber dam

isolation.

Post obturation radiograph

Post space preparation done

Fiber post cemented with dual cure resin

cement

Core build up done with light cure composite

resin.

Reduction done and Desired tissue retraction

achieved

PFM crown placed

Pre- and post treatment views

Case Report #2

Pre-operative View

Pre operative radiograph

Removal of the carious lesions

Insertion of the parapost and etching of the remaining tooth portion

Core build up with composites

Tooth reduction done

PFM crowns placed

Pre- and post- t/t comparison

Post operative radiograph

Case

Case

Conclusion The results of endodontic treatment are influenced by a

number of biological and technical factors like diagnosis, root

canal morphology, root canal instrumentation and

obturation, and complications during the treatment.

Optimum result in any case can be achieved through proper

diagnosis, prompt treatment planning and due consideration

towards restoration of involved tooth to its proper form and

function.

Our treatment decisions must be governed by the best

available evidence i.e “Evidence Based Practice”.