basics of root canal treatmentthe results of endodontic treatment are influenced by a number of...
TRANSCRIPT
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”.