Internal anatomy of pulp space

+ Introduction
+ History
+ Development of pulp
+ Pulp cavity
 Laws Of Pulp Cavity
 Coronal pulp(Pulp chamber)
 Roof and Floor
 Pulp horns
 Canal orifices
 Radicular pulp(Root canal)
 Classification of root canals
Weine’s classification(1969,1982)
Vertucci’s classification(1974)
Grossman’s classification

 Gulabiwala and Coworkers(2001)
 Seit and Bayirili(2001)
 Yoshioka and Villegas(2004)
 Other classifications
o Classification by H M AAhmed(2017)
o Classification by Rashmi Bansal et al.(2018)
 Isthmus
o Identification
o Classification
o Clinical Significance
 Root canal ramification
Terminologies
Classification of root canal ramification
 Accessory Canal
o Incidence

o Formation
o Classification of accessory canal
o Clinical significance
 Concept of radius of curvature and angle of curvature
 Classification of root canal curvature
 Ingle and Taintor(1980) and Pucci and Reig(1986)
 Zeidle’s classification of root canal system(1986)
 Schneider’s classification(1986)
 Wein’s classification
 Csaba Dobo Negi et al(1995)
 Relationship between degree of curvature and ledge
formation
 Management of apical curvature
 Management of curvature in middle third
+ Regressive changes in anatomy of root canal

+ Apical root anatomy
 Minor Constriction
o Introduction
o Topography
o Position
 Major constriction
o Introduction
o Location
o Associated studies
 Cementodentinal Junction
 Radiographic apex
 Significance of apical third
 Optimal working length
 Apical tissue

+ Variations in the pulpal anatomy of teeth
 Variations in development
 C-shaped
oIntroduction
oIncidence
oClassification(Melton’s and Fan’s classification
for C-shaped canal)
oExternal root anatomy of C shaped canal
configuration molar
oSignificance
oManagement of C shaped canal
Access cavity preparation
Biomechanical preparation
Obturation
Post endodontic restoration

 Gemination
 Fusion
 Concrescence
 Taurodontism
 Talon’s cusp
 Dilaceration
 Dentinogenesis imperfecta
 Dentin Dysplasia
 Extra root canal
 Missing root
 Dens evaginatus
 Dens invaginatus

 Variations in shape of pulp cavity
 Gradual curve
 Apical curve
 C shaped canal
 Bayonet shaped
 Dilaceration
 Sickle shaped
 Variations in pulp cavity due to pathology
 Pulp stones
 Calcifications
 Internal resorption
 External resorption
 Variations in apical third
 Different locations of apex
 Accessory and lateral canals
 Open apex

+ Methods of determining pulp anatomy
 Clinical methods
 Diagnostic method
 Anatomic studies
 Radiographs
 Radiovisiography
 Cone beam computed tomography
 Dental operating microscope
 Fiberoptic endoscope
 Magnetic resonance imaging
 Visualisation endogram
 In vitro methods
 Sectioning of teeth
 Use of dyes
 Filling and Clearing of teeth

 Contrasting media
 Radiography
 Scanning electron microscopic analysis
+ Factors affecting internal anatomy
– Age
– Irritant
– Calcification
– Resorption
+ Pulp space anatomy of permanent teeth
 Maxillary central
 Maxillary lateral incisor
 Maxillary canine
 Maxillary first premolar
 Maxillary second premolar
 Maxillary first molar

 Maxillary second molar
 Maxillary third molar
 Mandibular central
 Mandibular lateral incisor
 Mandibular canine
 Mandibular premolars
 Mandibular first molar
 Mandibular second molar
 Mandibular third molar
+ Difference from primary teeth
+ Conclusion
+ Previously asked questions

Attempting to treat the root-canal system
without detailed anatomic description
would be equivalent of a physician
looking for an appendix without ever
having read Gray’s Anatomy.
-Paul Krasner

INTRODUCTION
+ Of all the phases of anatomic study in the human system, one of
the most complex is the pulpal morphology.
+ For succcess of endodontic therapy, knowledge of pulp anatomy
cannot be ruled out.
+ It is essential to have the knowledge of normal and usual
configuration of the pulp cavity along with variations.

1842:Investigation of tooth
anatomy
CARABELLI: published
drawings of sectioned teeth
detailing the root canal system
1870: MUHLREITER -first
one to investigate root canal
anatomy, sectioned teeth in all
planes & described the internal
anatomy with details 1890: G. V. BLACK-contributed
with the study of the root canal
anatomy in the 1st edition of his
book
1892: ALFRED GYSI-
presented pictures of
histological sections of the
tooth showing the complexity
of the internal anatomy.
1901:PREISWERCK -injected
molten metal within the pulp
followed by complete
decalcification of tooth and obtained
a metal model of internal anatomy
Diwan A, Sreedevi CR, Nagaraj T, Raghava V, Sinha P, Moushmi CB. Determination of internal anatomy of a permanent dentition: A review. Int J
Contemp Dent Med Rev. 2015;2015.
HISTORY

1907: FISCHER- used celluloid
instead of metal
Better results, small ramifications
of the replicas broke easily as
celluloid was fragile.
1916: DEWEY –injected
paraffin to study the root canal
anatomy.
1917: HESS- injected root canals
with vulcanized rubber, removed
hard tissue by decalcification.
Material:still valuable to the study
of the root canal anatomy.
1918-1926: OKUMARA-
studied internal anatomy of
teeth using injection of dye &
diaphonization
1923: CLYDE DAVIS- studied the
anatomy of the apical third using
ground sections of the tooth.

1960: DE DEUS- first author to
study systematically root canal
anatomy of all dental groups using
clearing technique
(diaphonization).
1925: BARRET-studied the
dental anatomy using serial
histological sections
1955:MEYER & SCHEELE-
using wax models
demonstrated numerous lateral
canals in the apical third of the
root
1974: VERTUCCI &
WILLIAMS- found a
complex root canal system and
identified eight conﬁgurations
of the pulp space
1969:WEIN- first to categorize
root canal configurations within
a single root
2017:H M A AHMED- A new
system for classification of
root & root canal morphology

+ Begins at 8th week of intrauterine life
CEMENTUM

+ Lies within the tooth
+ Enclosed by dentin all around except apical foramen
Endodontic Science, Carlos Estrela, Volume 1 , 2nd edition,Page-531
Coronal pulp: Pulp chamber
Radicular pulp: Root canal

PULP CAVITY
PULP CHAMBER
ROOT CANAL
Roof
Floor
Pulp horn
Canal Orifice
Accessory and
Lateral Canals
Accessory
Foramina
Apical
delta
Apical foramen
Krasner P, Rankow HJ. Anatomy of the pulp-chamber floor. Journal of endodontics. 2004 Jan 1;30(1):5-16.

Krasner and Rankow: studies pulp chamber of 500 extracted teeth
Anatomic Laws
1. Relationship of pulp
chamber to crown
2. Relationship of root canal
orifice to pulp chamber floor

floor of the pulp
chamber is always
located in center of
the tooth at the level
of the CEJ
Law of
centrality
walls of the pulp
chamber are always
concentric to external
surface of the tooth at
the level of CEJ
Law of
concentri
city
Relationship of pulp chamber to crown
CEJ is the most
consistent, repeatable
landmark for locating the
position of the pulp
chamber
Law of
CEJ

Law of symmetry 1:
except for maxillary
molars, orifices of
canals are equidistant from
a line drawn in a mesial
distal direction through the
pulp-chamber floor.
Law of symmetry 2:
except for the maxillary
molars, orifices
of canals lie on a line
perpendicular to a line
drawn in a mesial-distal
direction across the
center of the floor of the
pulp chamber
Relationship of root canal orifice to pulp chamber
floor

the color of the
pulp-chamber
floor is always
darker than the
walls
Law of
Color
Change:
orifices of root
canals are always
located at the
junction of the
walls and the
floor
Law of
orifice
location 1:

the orifices of the
root canals are
located at the
angles in the
floor-wall
junction
Law of
orifice
location
2:
orifices of root
canals are located
at the terminus of
the root
developmental
fusion lines
Law of
orifice
location 3

• Acquires shape and size of crown of the tooth
+ Roof :
 Dentin covering the pulp chamber occlusally or incisally.
+ Floor :
 Dentin bounding the pulp chamber near the cervix of the tooth
particularly that forming the furcation area
 Parallel to roof
Roof
Floor

+ Walls and angles :
 Walls: correspond to respective walls of the tooth surface.
 Angles correspond to the respective angles formed from the
walls of pulp chamber.
+ Pulp horns:
 Between occlusal and pulp chamber
 Accentuation of roof of pulp chamber directly under a cusp or
developmental lobe
+ Canal orifices:
 Openings in the floor of pulp chamber leading to root canals
 Continuous with pulp chamber and root canal

+ From canal orifices to apical foramen
+ Anterior teeth: Pulp chamber merges into root canal
+ Posterior teeth: Division becomes quite obvious

Bansal R, Hegde S, Astekar M. Classification of Root Canal Configurations: A Review and a New Proposal of Nomenclature System for Root Canal
Configuration.Journal of Clinical and Diagnostic Research,2018.
•Weine et al. (1969) : first to categorize root canal configurations
within a single root
•Weine (1982): Type IV

Vertucci et al. (1974): based on evaluation of 200 cleared maxillary
2nd premolars in which the pulp cavities were stained with dye

+ Seit and Bayirili in 2001 reported: 14 new root canal
configuration
Ahmed HM, Versiani MA, De‐Deus G, Dummer PM. A new system for classifying root and root canal morphology. International endodontic
journal. 2017 Aug;50(8):761-70.

+ Yoshioka and Villegas in 2004: Type V to Wein’s classification
+ Type V: A root canal configuration having more than 2 canals
that branched off from the main canal more than 3mm from the
apex defined as another main canal

+ Christie wt al(1991), Carlsen & Alexandersen (2000), Baratto‐Filho
et al.( 2002), Versiani et al (2012): Maxillary molars with four roots
+ Carlsen & Alexandersen (2000), Baratto‐Filho et al. (2002), Versiani
et al. (2012): maxillary premolars with three canals
+ Belizzi & Hartwell (1981), Ahmed & Cheung (2012): the middle
mesial canal
+ Pomeranz et al. (1981): distolingual root in mandibular molars
+ Kottoor et al. (2012) and Albuquerque et al. (2012) suggested a new
nomenclature to classify root canal anatomy in maxillary and
mandibular molars, respectively.

+ Simple, accurate and useful :information on root and root
canal anatomy.
+ Does not address the degree of root and root canal curvature,
degree of root/canal separation, exact level of bifurcation of
canals/roots, accessory canals
+ Codes for three separate components: the tooth number, the
number of roots and their configuration, and the root canal
configuration

Tooth number:FDI
Root nomenclature:
right side
Course of canal:
bracket
Foramen through
which canal is
exiting at the apex:
after slash
Anatomic
Variations: Left eg.
C shaped canal-
C,Taurodont-T
Single root as R in
the right side,

+ Narrow ribbon shaped communication between the root canals
containing pulp or pulpally derived tissues is called isthmus

+ Nidus for recurrent infection
+ Highest incidence: Mesial root of mandibular 1st molar
+ Cambruzzi & Marshall: Use of methylene blue dye for
visualisation
+ Microscope: for identification
+ Ultrasonic :tips for preparation and filling

+ Main canal: Present in longitudinal axis,
passes from roof of pulp chamber to apical
foramen
+ Collateral canal: Located parallel to main
canal, either capable of being reached or not
by isolating the apical foramen, smaller in
volume than main canal

+ Lateral canal: In cervical third and
beginning of middle third, either
perpendicular or not
+ Secondary canal: Apical third, either
perpendicular to main canal or not
+ Accessory canal: Ramification of secondary
canal which goes in direction of periodontium
+ Intercanal: Ramification between main and
collateral or secondary canal
+ Recurring canal: Part of main canal not
going through a discrete passage and
returning to main canal

+ Reticular canal: Represents the mixture of three or more canals,
ramification of the intercanal
+ Apical delta: Triangular area of root surrounded by main canal,
accessory canal and periradicular tissues

+ Mitchell(1965): auxiliary, reticular and recurrent canals
+ De-Deus(1975): lateral canal, secondary canal and the accessory
canal
+ AAE 2016:
 Accessory canal: branch of the main pulp canal or chamber
that communicates with the external root surface.
 Lateral canal: type of accessory canal, located in the
coronal or middle third of the root, extending horizontally
from the main canal space
 Furcation canal: an accessory canal located in the furcation

+ Accessory canal: Fibrous tissue and connective tissue same as that
of pulp but closely resembles connective tissue of periodontal
ligament
+ Incidence: 2 to 3- 72% in posterior teeth
35% in anterior teeth(Seltzer,1966)
73.5% : apical third
11.4% : middle third
15.1%: cervical third
Formation: Entrapment of PDL vessel in HERS during
mineralisation
Alothmani OS, Chandler NP, Friedlander LT. The anatomy of the root apex: A review and clinical considerations in endodontics. Saudi Endodontic

Detection of accessory canal:
+ Thickening of PDL or lesion in lateral wall of root
+ Usually becomes noticeble post obturation
+ Bulbous root: more ramification
+ Tortuous root canal or sharp bend in root: more chances
Clinical significance:
+ Interchange of irritants
+ Deep periodontal pocket: Channel for toxic products into
pulp
+ Inflammatory pulp tissue: Effect on periodontal tissue

+ Yoshiuchi et al. (1972): staining and clearing method
+ Based on the region of the root: Kasahara et al. (1990),
Miyashita et al. (1997), Adorno et al. (2010)
Accessory canal at 5/10–9/10, 4/10–2/10, 1/10
or less of the root length: cervical, middle or
apical location, respectively
Ahmed HM, Neelakantan P, Dummer PM. A new system for classifying accessory canal morphology. International endodontic journal. 2018 Feb

Ahmed HM, Neelakantan P, Dummer PM. A new system for classifying accessory canal morphology. International endodontic journal. 2018 Feb

Lesser radius of
curvature
Less fatigue of
instruments

Ingle and Taintor(1980) and Pucci and Reig(1986)
+ Apical curve
+ Gradual curve
+ Sickle shaped
+ Dilaceration
+ Bayonet
Balani P, Niazi F, Rashid H. A brief review of the methods used to determine the curvature of root canals. Journal of Restorative Dentistry. 2015
Sep 1;3(3):57.

Zeidle’s classification of root canal system(1986)
+ Severe curve
+ Dilacerated curve
+ Bayonet curve
+ Apical bifurcation
+ Apical curve
+ Additional canals
+ Lateral and Accessory canals
Sep 1;3(3):57.

•a mid-point marked on the file
at the level of canal orifice
•straight line drawn parallel to
the image and that point is
labeled as point A
•second point is marked where
the flare starts to deviate that is
labeled point B
•third point is marked at the
apical foramen and is termed
point C and the angle formed by
the intersection of these lines is
measured
Easy: straight and curved less
than 5 degree
Average: curved more than 10
less than 25
Difficult: curved more than 25
Schneider’s classification(1986): Based on degree of curvature in root
canal, measured using protactor
Sep 1;3(3):57.

Sep 1;3(3):57.
Point A: at the center of the canal
orifices
Point B: 2 mm below the orifices in the
long axis of the canal
Primary line: Point A and Point B
Point C: 1 mm coronal to the apical
foramen
Point D: At apical foramen
Secondary line: Point C and Point D

Weine’s classification:
+ Curvature of 30 to 45 degree
+ Curvature more than 90 degree
+ Bayonet shaped curve
+ Backman et al(1976) and Southard et al(1990) : Based on
radius quotient(angle divided by radius)
+ Dabo Negi et al: Schnieder’s angle and radius of circle
superimposed on curved part of root canal
Sep 1;3(3):57.

Csaba Dobo Negi et al(1995)
+ Straight or ‘I form’
+ Apical curve or ‘J form’
+ Curved canal along its entire length or ‘C form’
+ Multicurved or ‘S form’
Sep 1;3(3):57.

Sep 1;3(3):57.
(More than 20O

Apical curvature:
+ Straight line access
+ Start : smaller diameter K file such as #08 or #10(precurved)
+ Chelating agent (EDTA) ,irrigation with sodium hypochlorite
+ Segal: reamer instead of K-file, more flexible .
– Once removed, describes the degree, type, location, and
direction of the curvature,
– Due to its flexibility may lead to canal transportation.
+ Stainless steel files of smaller diameter with light passive
movement ,diameter of glide path is then increased with nickel-
titanium (NiTi) hand files before the preparation of the canal with
rotary NiTi file
Sep 1;3(3):57.

Managing middle curvature
+ Adequate access and good coronal third preparation
+ Coronal third preparation followed by the mid-portion
preparation using precurved files
+ Precurved file: negotiating the canal and makes a glide path
before rotary NiTi files are introduced for cleaning and shaping
Sep 1;3(3):57.

+ Receded pulp horns
+ Shorter and smaller pulp chamber
+ Narrower root canals( due to secondary or reparative
dentin deposition)
+ Narrower minor diameter, wider major diameter
+ Reduced no. of accessory foramina(due to calcification of
contained soft tissue)
+ Narrower or obliterated dentinal tubules
Receded pulp horns
Shorter and smaller pulp chamber
Narrower root canals( due to
secondary or reparative dentin
deposition)
Narrower minor diameter and
wider major diameter
Reduced no. of accessory foramina(due
to calcification of contained soft tissue)
Narrower or obliterated dentinal
tubules

+ Apical constriction(minor
diameter/physiological foramen):
 Apical part of root canal having
narrowest diameter short of apical
foramina or radiographic apex
May or may not coincide with CDJ
Histologically: at the junction
between pulpal connective tissue and
interstitial loose connective tissue of
periodontal ligament
Journal. 2013 Jan 1;3(1):1.

Dummer et al:
+ Type A: Single constriction
+ Type B: Tapering
constriction with narrowest
portion of canal very near
to actual apex
+ Type C: Number of
constrictions present
+ Type D: Constriction
followed by narrow,
parallel portion of canal
+ 5th type: canal completely
blocked with secondary
dentin or cementum
Journal. 2013 Jan 1;3(1):1.

The distance between the AC and AF ranged between 0.4-1.2 mm, while its
reported location in relation to the root apex ranged between 0.5-1.01 mm
Journal. 2013 Jan 1;3(1):1.

+ Apical foramen(major diameter):
Main apical opening on surface of
root canal through which blood
vessels enter
Diameter: almost double the apical
constriction, funnel shaped described
as morning glory or hyperbolic
+
Journal. 2013 Jan 1;3(1):1.

+ Changes as a result of functional influence on the teeth
+ Mesial migration or tipping: apex tilt to opposite side
+ Tissues entering pulp exert pressure on one wall of foramen :
resorption and cementum deposition on opposing wall
+ Shifts with: Aging, mesial migration, occlusal drift and
continuous cementum deposition
Journal. 2013 Jan 1;3(1):1.

Deviation of the AF from the root apex is common, with a reported frequency
ranging from 17-100%
Journal. 2013 Jan 1;3(1):1.

Green’s study(1955,1956 and 1960): Major apical foramen
situated directly at apex more frequently in:
+ Maxillary first premolar and mandibular second premolar
+ Maxillary central and lateral incisor
+ Maxillary molars and all mandibular teeth with exception of
2nd premolar: main apical foramina coincides with apices less
frequently
Green D.A stereo-binocular microscopic study of the root apices and surrounding areas of 100 mandibular molars.Oral Surg Oral Med Oral Pathol
1955;8:1298–1304.
Green D.A stereomicroscopic study of the root apices of 400 maxillary and mandibular anterior teeth. Oral Surg Oral Med Oral Pathol 1956;9:1224–
32.
Green D. Stereomicroscopic study of 700 root apices of maxillary and mandibular posterior teeth. Oral Surg Oral Med Oral Pathol 1960;13:728–33.

+ Mean distance between major and minor diameter
+ Increased length in older individual: increased cementum
+ Cementodentinal junction: Usually lies 0.1mm from the apical
foramen
+ Tooth apex: Radiographic apex
Young person: 0.5mm
Older person: 0.7mm
Journal. 2013 Jan 1;3(1):1.

SIGNIFICANCE OF APICAL THIRD
+ Great degree of variation in shape and size: problem during
endodontic procedure
+ Presence of accessory canal, pulp stones, areas of resorption,
irregular secondary dentin: alter root canal therapy
+ Most of the curvature occurs in this area
+ Obturation should end at apical constriction
+ Apical 3mm is resected during endodontic surgery to eliminate
canal abberations
Journal. 2013 Jan 1;3(1):1.

Several apical reference points
CDJ:
•Prevent microbial escape into periapical tissues & block
entry of tissue fluids into canal space (theoretically)
•Histological point: cannot be located clinically and its
appearance varies from tooth to tooth
•Few teeth: located inside the root canal
Apical foramen:
•Cleaning and shaping short of AF: entire procedure is
performed within root canal regardless of the position or
existence of AC
•Accurate location of the AF is only possible histologically
Journal. 2013 Jan 1;3(1):1.

Apical constriction:
•Result in least amount of tissue damage
•Quality guidelines of European Society of Endodontology
(2006) :working length determination should be as close as
possible to the AC.
•Divergent shape of canal apical to AC: difficult to adequately clean.
•Most favorable histological response at the periapical region:
instrumentation and filling ended at the level of the AC
•Method of identifying AC not clear, teeth prepared 1 mm short of
radiographic apex if the AF could not be identified radiographically
Journal. 2013 Jan 1;3(1):1.

Apical constriction:
•Instrumentation at level of AC: better treatment outcomes.
•Kuttler: all root canal procedures should terminate 0.5 mm short of
AF(nearest to AC)
•Risks: leaving diseased tissue apical to AC.
•Histologically not identified in many teeth.
•Clinically: setting WL 1 mm short of radiographic apex may position
the file exactly at AC in 22%, 35% and 11% of anteriors, premolars &
molars respectively
•Cementum deposition: alters relation of radiographic apex to AC
Journal. 2013 Jan 1;3(1):1.

Radiographic apex
•Include all apical ramifications in the disinfection and root
filling procedures
•Simon: suggested instrumentation to the radiographic apex and
then stepping back to create an apical stop for the root filling
•Results in under- or over-instrumentation as AF is usually not
located at the radiographic apex.
•in vitro:50% of the teeth had files extending beyond the AF
when inserted till radiographic apex.
•in vivo:extended beyond the AF in most cases
Journal. 2013 Jan 1;3(1):1.

Journal. 2013 Jan 1;3(1):1.
Normal periapical tissue: Working length 1mm short of
radiographic apex
Bone resorption: 1.5 mm short of apex
Bone and apex resorption: 2mm short of apex

Journal. 2013 Jan 1;3(1):1.
More fibrous, fewer cells
Histologically (Yamashi et al,1986): larger concentration of
glycogen, a condition compatible for presence of anaerobic
environment
Gross appearance: Collagenous tissue white in colour
Fibrous tissue: acts as barrier against apical progression of
pulpal inflammation

+ Root and their root canals with their cross-sectional morphology C-
shaped are called C-shaped canals
+ First documented in endodontic literature : Cooke and Cox in 1979
+ Fusion of mesial and distal roots on either buccal or lingual root surface
or due to failure of HERS to fuse on buccal or lingual root surface
+ Most common: Mandibular 2nd molars
+ May also be seen in: Mandibular 1st molar, Maxillary 1st and 2nd molar
+ Common in Asians and Caucasians
Cooke HG, Cox FL. C-shaped canal configurations in mandibular molars. The Journal of the American Dental Association. 1979 Nov 1;99(5):836-9.

•High prevalence in mandibular
second molars
(2.7%-45.5%).
•Incidence studies in mandibular
premolars have been reported in
Chinese, Indian and Iranian
population, with the highest
frequency being reported in the
Chinese population (29.7%).
•Bilateral occurrence of C-shaped
canals: 70%-81%.
Fernandes M, De Ataide I, Wagle R. C-shaped root canal configuration: A review of literature. Journal of conservative dentistry: JCD. 2014
Jul;17(4):312.

Jul;17(4):312.

Jul;17(4):312.
Type I: Canals merge
into one before exit
Type II: 2 Canals-
separate exit
Type III:1 canal
curved and
superimposed to
radiolucent line

+ A conical or square configuration of roots
+ Roots: occluso-apical groove on the buccal or lingual surface,
(line of fusion between mesial and distal roots)
+ pulp chambers :greater apico-occlusal width with a low
bifurcation
+ root canal system: broad, fan-shaped communications from the
coronal to the apical third of the canal
Jul;17(4):312.

+ four radiographic characteristics that can allow prediction of
the existence of this anatomical condition:
 radicular fusion
 radicular proximity
 a large distal canal
 blurred image of a third canal in between.
+ Crown morphology: does not present with any special features
that can aid in the diagnosis.
+ A longitudinal groove on lingual or buccal surface of the root
with a C-shaped anatomy may be present.
Jul;17(4):312.

+ Continuous C-shape or arc like Mesiobuccal-Distal (MB-D)
+ Number of canals: one to three
+ Oval or flat orifice: one or two canal
+ Round orifice: usually only one canal
+ Continuous C-shape orifice: 3 initial files are inserted, one at
either end and one in the middle.
+ Oval orifice: two files inserted, one file at each end of the
orifice
+ Exploration: small size endodontic files,(no. 8, 10, 15 K-file)
with a small, abrupt apically placed curve, to ensure that
irregularities are not missed.
Jul;17(4):312.
ACCESS CAVITY PREPARATION

• Cleaning and shaping
• Orifice : widened with Gates Glidden drills.
+ C1 (continuous C type) & C2 (semicolon type) configurations
:always have a narrow isthmus, avoid perforation during their
preparation.
+ Narrow isthmus areas: GGdrills should not be used, cleaning
should be carried out using a size 25 instrument or smaller.
+ High risk of root perforation at the thinner lingual walls of C-
shaped canals during cleaning and shaping.
Jul;17(4):312.

+ Nickel-titanium rotary instruments safe
+ Enlargement to an apical dimension greater than size 30 (0.06
taper): not recommended.
+ Self-adjusting file (SAF) system: more efficacious than the
protaper system for shaping of C-shaped canals.
Jul;17(4):312.

+ Large canal space: intracanal
instruments reaching and
debriding the entire portion is
doubtful, irrigation procedures
more significant.
+ Cleaning of the C-shaped canal
system with rotary instruments:
assisted by ultrasonic irrigation.
+ Use of chemical agents for
disinfection: calcium hydroxide
as an intracanal medicament for a
period of 7-10 days.
Jul;17(4):312.

Obturation
Barnett technique:
Placing a large diameter file in the most distal portion of the canal
Seating the master cone in the mesial canal
File is withdrawn and the master cone of the distal canal is seated
Placement of accessory cones in the middle portion of the C-
shaped canal.
Jul;17(4):312.

+ Following cleaning and shaping: RDT around canals usually
0.2 to 0.3 mm.
+ Resultant forces of compaction during obturation can exceed
the dentin canal resistance resulting in root fracture and
perforation of the root.
+ Thermoplasticized gutta-percha technique may prove to be
more beneficial.
+ Aim of this technique: move gutta-percha and sealer into root
canal system under hydraulic force.
Jul;17(4):312.

+ C-shaped canals : hydraulic forces can dramatically decrease
and can seriously compromise the obturation quality due to:
+ (a) there are divergent areas that are frequently unshaped, which
may offer resistance to obturating material flow
+ (b) communications exist between the main canals of the C-
shape through which the entrapped filling materials that should
be captured between the apical tug back area and the level of
condensation may pass from one canal to another.
Jul;17(4):312.

To overcome these: Walid's technique
+ Placing the master points simultaneously in the C-shaped
canal
+ Large plugger is placed on one of the seared master points
while the other master point is down packed with a smaller
plugger.
+ This increases the resistance towards the passage of obturating
material from one canal to another.
+ The smaller plugger is then held in place while the other point
is down packed.
+ This offers backpressure on entrapped filling materials and
enhances the seal.
Jul;17(4):312.

Post endodontic restorations
Prefabricated or cast posts increase the risk of creating a strip
perforation.
No prefabricated post (circular or conical i.e. of a circular cross
section) would fit the C-shaped canals.
Since the floor of the pulp chamber is deep: provide ample
retention from the available undercuts.
Chamber-retained, bonded amalgam or composite: better
choice as the core or as the final restoration in these teeth.
Jul;17(4):312.

GEMINATION
Attempt at division of a single
tooth resulting in incomplete
formation of two teeth
Mahendra L, Govindarajan S, Jayanandan M, Shamsudeen SM, Kumar N, Madasamy R. Complete bilateral gemination of maxillary incisors with

Mahendra L, Govindarajan S, Jayanandan M, Shamsudeen SM, Kumar N, Madasamy R. Complete bilateral gemination of maxillary incisors with
Before treatment.
Study Cast
Intraoral periapical radiographs showing pre- and
postendodontic treatment.
Clinical photograph of split crowns

FUSION
 Union of two normally separated tooth germ
 Separate or fused pulp space
Chipashvili N, Vadachkoria D, Beshkenadze E. Gemination or fusion?-challenge for dental practitioners (case study). Georgian Med News. 2011
May;194:28-33.

+ Localization and access to the canals might pose additional
difficulties.
+ Internal morphology varies and pulp chambers may be
together or separated.
+ Communication between pulp chambers of fused teeth:
common.
Chipashvili N, Vadachkoria D, Beshkenadze E. Gemination or fusion?-challenge for dental practitioners (case study). Georgian Med News. 2011
May;194:28-33.

Clinical view of the fused
teeth before treatment
Separated pulp chamber and two root canals.
Palatal view of endodontic access cavity.
Radiographic view of teeth after treatment.
Clinical view of resin composite veneer
restoration.
Radiographic view of teeth at the
end of one month.

CONCRESCENCE
 Fusion after root formation
 Joined by cementum only
Law L, Fishelberg G, Skribner JE, Lin LM. Endodontic treatment of mandibular molars with concrescence. Journal of Endodontics. 1994 Nov

Law L, Fishelberg G, Skribner JE, Lin LM. Endodontic treatment of mandibular molars with concrescence. Journal of Endodontics. 1994 Nov

TAURODONTISM
 Body of tooth enlarged at expense of root(Bull like teeth)
 Pulp chamber: extremely large(greater apicoocclusally)
 Pulp: Lacks normal constriction at cervical region
 Conditions: Klienfelter’s and Down’s syndrome
Jafarzadeh H, Azarpazhooh A, Mayhall JT. Taurodontism: a review of the condition and endodontic treatment challenges. International
endodontic journal. 2008 May;41(5):375-88.

+ Wide variation in size and shape of pulp chamber
+ Varying degrees of obliteration and canal configuration
+ Apically positioned canal orifices and potential for additional root
canal systems
+ Shifman & Buchner (1976): access to root canal orifices can easily
obtained as floor of pulp chamber not affected by the formation of
reactional dentine as in normal teeth.

+ Durr et al. (1980): morphology could
hamper the location of the orifices, thus
difficulty in instrumentation and filling
+ Exploration of grooves between all
orifices, with magnification (Tsesis et
al. 2003): additional orifices and canals
+ Complete removal of necrotic pulp :
2.5% sodium hypochlorite initially as an
irrigant to digest pulp tissue(Prakash et
al. 2005).
+ Application of final ultrasonic
irrigation: ensure no pulp remains
(Prakash et al. 2005).

+ Modified filling technique: combined lateral compaction in apical
region with vertical compaction of elongated pulp chamber
(Tsesis et al. 2003).
+ Hypertaurodont: vital pulpotomy instead of pulpectomy-treatment
of choice (Shifman & Buchner 1976, Neville et al. 2002).
+ PRosthetic treatment: post-placement avoided for tooth
reconstruction less surface area of the tooth is embedded in the
alveolus (Tsesis et al. 2003).

Chowdappa NS, Hegde MN, Shetty S, Bhat GT. " Management of taurodont right mandibular second molar tooth": A case

TALON’S CUSP
 Resembles eagle’s talon
 Projects lingually from cingulum area of maxillary or
mandibular incisor
 varying extensions of pulp tissue, or maybe devoid of pulp
tissue
Shafer’s Oral Pathology, 7th edition

+ DILACERATION
+ Extraordinary curving of root
Etiology: Trauma during root development
Jafarzadeh H, Abbott PV. Dilaceration: review of an endodontic challenge. Journal of endodontics. 2007 Sep 1;33(9):1025-30.

+ “Scout file” : provide critical information regarding extent
and direction of root canal dilaceration
+ Greater incidence : blocking, ledging, apical cavitation like
transportation or zipping, perforation & instrument breakage
+ Precurvature of files: depends on curvature of the canal, size of
the instrument and depth at which instrument is to be used

+ Severely curved canals:Instruments discarded after use(“single
use instruments”)
+ Multi-visit approach : interappointment intracanal
medicaments
+ Calcium hydroxide with glycerin rather than with sterile
water.
+ Glycerin : significantly superior to water in regards to the length
of filling and density in the apical third of curved canals

+ DENTINOGENESIS IMPERFECTA
+ Defective formation of dentin
+ Partial or total obliteration of pulp chamber or root canal due to
continued formation of dentin
Yeh PY, Pai SF, Lee YY, Yang SF. Dentinogenesis imperfecta: a challenge for root canal treatment-case report. Journal of Dental Sciences. 2008

+ Multiple-purpose probes , Surgical-length contra-angle burs &
Chelating agents: help gain access and improve the possibility
of negotiating calcified canals
+ Perforations and ledges are common
+ Chelating agents not advised: further softening of original
defective dentin
+ Periapical surgery: for a tooth with persistent apical pathosis
+ Rotary instruments : gentle force and as few times as required
Yeh PY, Pai SF, Lee YY, Yang SF. Dentinogenesis imperfecta: a challenge for root canal treatment-case report. Journal of Dental Sciences. 2008

+ DENTIN DYSPLASIA
+ Characterized by formation of normal enamel, atypical dentin and
abnormal pulpal morphology, Obliterated canals
Contemp Dent Med Rev. 2015;2015

+ DENS INVAGINATUS(DENS IN DENTE)
+ Exaggeration of lingual pit
 Invagination of enamel organ into the dental papilla before
calcification has occur
 Most commonly: max lateral incisor
 Tendency of plaque accumulation: predisposes to decay
Gallacher A, Ali R, Bhakta S. Dens invaginatus: diagnosis and management strategies. British dental journal. 2016 Oct;221(7):383.

+ Two canal orifices: one regular and one invagination opening
+ May present with wide open or ‘blunderbuss’ open apices
+ Class II lesions(close proximity with pulp): the invagination
dressed with mineral trioxide aggregate (MTA), remaining
defect restored with composite resin.

+ Ultrasonic alloy tips: debride the lesions
+ Irrigants :ultrasonically activated to maximise their efficacy
and ensure that they reach all parts of the anomaly.
+ Pulpal portion of the tooth: treated with endodontic files,
thorough irrigation of sodium hypochlorite
+ Thermoplastic gutta percha (to ensure that the complex
anatomy has been completely sealed)

+ DENS EVAGINATUS
+ Anamolous tubercle or cusp on occlusal surface
 Tubercle wears off fast: Early
exposure of accessory pulp horn
that extend into tubercle
 May result in periradicular pathology in otherwise caries free
teeth
 Common: Premolars
Ayer A, Vikram M, Suwal P. Dens evaginatus: a problem-based approach. Case reports in dentistry. 2015;2015.

+ Usually contains pulp tissue
+ Trauma during mastication fracture of the tubercle
necrosis of pulp and periapical infection
+ Vital pulp: selective reduction of opposing occluding teeth
+ Fractured tubercle: it can be sealed with resin.
+ Pulp exposure(early phase of root development): mineral
trioxide aggregate (MTA) pulpotomy.
+ Necrotic pulp: MTA root end barrier(immature apex) and
conventional root canal treatment(mature tooth)
Ayer A, Vikram M, Suwal P. Dens evaginatus: a problem-based approach. Case reports in dentistry. 2015;2015.

+ Gradual curve: Most common
+ Apical curve: Commonly seen in maxillary lateral incisor and
mesiobuccal root of maxillary molar
+ C-shaped canal: Common in mandibular molars

+ Bayonet shaped canal: Common in premolars
+ Sickle shaped canal: Common in mandibular molars, Canal: Ribbon
shaped
Sakkir N, Thaha KA, Nair MG, Joseph S, Christalin R. Management of Dilacerated and S-shaped Root Canals-An Endodontist’s Challenge.
Journal of clinical and diagnostic research: JCDR. 2014 Jun;8(6):ZD22.

+ Strip perforation: very high.
+ Guttman: preflaring the
coronal 1/3rd of the
canal(reduce the angle of
curvature).
+ Precurving the file: A
precurved file traverses the
curve better than a straight file.
+ Precurving is done in two
ways:
– Placing a gradual curve for
the entire length of the file
– Placing a sharp curve of
nearly 45° near the apical
end of the instrument

+ Smaller number files :follow
canal curvature(flexibility).
+ Intermediate size files: allows
smoother transition of
instrument sizes to cause
smoother cutting in curved
canals (cutting 1 mm of No. 15
file makes it No. 17 file as there
is an increase of 0.02 mm of
diameter per mm of length).
+ Flexible files (NiTi files, Flex R
files): maintain shape of curve
& avoid procedural errors
(ledge, zipping).

+ Coronal pre-flaring and crown down technique.
+ Balanced force technique: less prone to cause iatrogenic
damage, decreases the extrusion of debris apically and
maintains the instruments centrally within the root canal

+ Pulp stones and calcification: Calcified masses present in
either coronal or radicular pulp or both
 50% of teeth
 Due to injury or normal phenomenon
 Calcification sometimes obliterate the pulp
Shafer’s Oral Pathology, 7th edition

+ For locating calcified canals: LN bur
(Caulk/ Denstply), the Mueller bur
(Brasseler, Savannah) and thin
ultrasonic tips.
+ Orifice location: DG-16 explorer.
+ Small files(No. 8 or No. 10 K –
file):to negotiate the canal.
+ Alternative option: Canal
Pathfinder(reduced flute), Pathfinder
CS-greater shaft strength ( Kerr
Manufacturing Co.)
Kothari H. Calcified Canals–A Review.IOSR Journal of Dental and Medical Sciences.2014;13(5):38-43
LN BUR
MUELLER BUR
ORIFICE LOCATION

+ Orifice not negotiated with a fine instrument: drill 1-2 mm into
the center of the orifice with a No.2 round bur on slow speed &
use the explorer to re-establish the canal orifice
+ Slow speed bur: remove whitish chips that accumulate in the
orifice.
+ Light stream of air blown into the chamber: chips appear as
white spots on dark floor of chamber and serve as markers for
exploration or further troughing

+ Grinding of floor: dark- colored dentin visible
+ Locating canals and initial penetration under the microscope is
also aided by fine instruments like the Micro- Orifice Opener

Biomechanical Preparation
+ Coronal flaring: crown- down fashion .
+ Incremental instrumentation: new increments between
established widths by cutting off a portion of the file tip(wider
in diameter).
+ Extremely sclerotic canals: 0.5 mm segments trimmed (width
increases by 0.01mm )
+ size 10 into a size 11 (cutting shaft-flat tip, a metal nail file used
to smooth the end and reestablish a bevel)

+ Chelator preparations: adjuncts for root canal preparation,
especially in narrow and calcified root canals.
+ Apical dentin: more frequently sclerosed and more mineralized.
+ EDTA solution into the pulp chamber (pipette, cotton pellet): to
identify the entrance to calcified canals.
+ EDTA: not used initially , may lead to transportation due to
increased dentin permeability

+ Internal resorption: Resorption begins centrally within the tooth
 Mostly initiated by: Inflammation of pulp
 Oval shaped enlargement of root canal space
 Common: Maxillary central incisor
 R/F: Smooth widening of root canal wall
Mittal S, Kumar T, Mittal S, Sharma J. “Internal root resorption: An endodontic challenge”: A case series. Journal of conservative dentistry: JCD.
2014 Nov;17(6):590.

+ Materials :
• MTA
• Glass ionomer cement
• Super EBA
• Hydrophilic plastic polymer (2-hydroxyethyl methacrylate
with barium salts)
• Zinc oxide eugenol
• Zinc acetate cement
• Amalgam alloy(not used)
• Composite resin(not used)
• Thermoplasticized gutta-percha(injection or condensation
techniques)
Mittal S, Kumar T, Mittal S, Sharma J. “Internal root resorption: An endodontic challenge”: A case series. Journal of conservative dentistry: JCD.
2014 Nov;17(6):590.

+ Nonsurgical pulp space therapy with a calcium hydroxide
dressing: Andreasen.
+ MTA: repair material due to superior sealing ability,
biocompatibility and fibroblastic stimulation.
+ Obturating material cold filling gutta-percha system
(GuttaFlow®2) combines two products in one: Gutta-percha in
powder form with a particle size of less than 30 μm and sealer.
+ Good flow properties, low solubility and tight seal of the root
canal due to its slight expansion, hence, no forces exerted on the
weakened tooth structure as in comparison to thermomechanical
or cold lateral compaction
Hegde N, Hegde MN. Internal and external root resorption management: a report of two cases. International journal of clinical pediatric
dentistry. 2013 Jan;6(1):44.

+ Different location of apical foramen
+ Accessory or lateral canals
+ Open apex(Blunderbass canal): Due to periapical pathology
before completion of root development or as a result of trauma
or injury causing pulpal exposure

1. Diagnostic Measures:
Exploration: Analysing
anatomy by an experienced
clinician
Troughing Grooves - with
ultrasonic tips
Champagne Bubble Test: with
sodium hypochlorite, bubbles at
canal orifice due to
liberation of free oxygen
Diwan A, Sreedevi CR, Nagaraj T, Raghava V, Sinha P, Moushmi CB. Determination of internal anatomy of a permanent

2.ANATOMIC STUDIES:
Basic anatomy and frequent variations can be studied before
endodontic procedure
3.RADIOGRAPHY: One of the most common methods of
analyzing pulp space by a clinician
 Disadvantage: 2dimensional
 Overlying canals: Clark rule or SLOB rule

 If canal suddenly stops in radicular region: bifurcated or
trifurcated.
 To confirm this 2nd radiograph with 10-30 degree mesial
angulation should be taken (Fast break appearance).

 Lateral radiolucency: Lateral canals
 Knob like image: Apex that curves towards or away
from the beam of the X-ray machine
 Multiple vertical lines: Possibility of thin roots

4.RADIOVISIOGRAPHY: Mouyen et al(1989)
+ Provides additional visual information more easily
because of mapping effect of radiopaque measuring
instruments
+ Advantages: Less exposure to radiation
Elimination of chemical processing

5. CBCT
+ 3D imaging of root canals
+ Computer image processing.
+ Obtains up to 600 distinct
images by rotating around
patients head.
+ Model can be rotated in any
plane in space and analyzed
internally and externally, can
be sectioned transversally and
longitudinally.
+ Canal volume can also be
evaluated.

6. DENTAL OPERATING MICROSCOPE
+ Nylen(1922): first to develop a monocular microscope.
+ Apotheker(1978): developed the dentiscope, commercially
available for dental surgery and other procedures.
+ Enables to take photos of high quality and magnification
for documentation

7. FIBEROPTIC ENDOSCOPE(ORASCOPE)
Magnified intracanal visualisation
0.7mm flexible fiberoptic endoscope: canal morphology
Difference between an orascope and an endoscope: orascope made
of fiber optics and an endoscope made of glass rods
Infection control: placing disposable, optical-grade, plastic sheaths
over the distal end of the probe

8. HIGH RESOLUTION COMPUTED TOMOGRAPHY
3D imaging of root canals, area, perimeter of cross-section
and volume can be evaluated

9. MAGNETIC RESONANCE IMAGING:
Permits creation of two and three-dimensional reconstructions
that can be rotated and sectioned.

+ Non-destructive method
+ Tutton et al.(2002): determine the roots of multi
rooted teeth, smaller branches of the
neurovascular bundle could be clearly identified
entering apical foramina.

10.VISUALISATION ENDOGRAM: Utilises Ruddle’s solution.
+ Solution is passively injected in canal and radiograph is taken.
+ Advantage: Irrigation as well as visualization
COMPONENTS
Sodium hypochlorite: Dissolves organic
tissues
17% EDTA: dissolves inorganic part
Hypque: Iodine containing radiopaque
contrast medium

Mechanism of action
+ Hypaque :visualize root canal system anatomy (water soluble and
radiopaque contrast solution).
+ Sodium hypochlorite : solvent.
+ EDTA: improved penetration
access cavity preparation
Injection of ruddle’s solution
Sodium hypochlorite dissolves the pulp and
eliminates the bacteria within the root canal system.
Iodine portion of the Ruddle’s solution flows into vacated
spaces which are cleared by the solvent action of the solution.

IN-VITRO METHODS
1. TOOTH SECTIONING

2. DYES:
Methylene blue, Fluorescein sodium
Stains vital or dystrophic pulp tissue

3. FILLING AND CLEARING
Tooth decalcified under 5% nitric acid or 10% hydrochloric
acid
dehydrated with varying concentration of alcohol
immersed in clearing agents(xylene, benzene, methyl
salicylate etc.)
Tooth becomes transparent and pulp space can be visualised
4. RADIOGRAPHY

5. CONTRASTING MEDIA:
Iodine containing radiopaque contrast media could be
ionic(Hypaque, Ruddle’s solution) or non-ionic(Saigram,
Iopamido)
Endogram: Radiographic appearance of pulp space in
the tooth after receiving radiopaque contrasting
media

6. SEM ANALYSIS:
Advanced and sophisticated method
Determine number and size of apical foramen,
accesory foramen and their distance from anatomic
apex

+ Uses focused beam of electrons for scanning a sample to
produce an image.
+ Its a microscope that uses electron instead of light to form
an image.
+ Advantages:
– Large depth of field
– Achieve resolution better than 1 nm.
– Specimens can be observed in high vacuum, in low
vacuum, in wet conditions, and at a wide range of
cryogenic or elevated temperatures.

PULP SPACE ANATOMY OF TEETH
+ 52 pulp organs:32(permanent)+ 20(primary)
+ Total pulp volume in permanent teeth: 0.38cc
+ Mean pulp volume: 0.02cc
+ Largest average pulp volume: Maxillary molar
+ Lowest pulp volume: Mandibular incisor

MAXILLARY
CENTRAL INCISOR
MAXILLARY
LATERAL INCISOR
Average tooth length 22.5 22 mm
Pulp chamber Equidistant from wall
3 pulp horns
Wider & ovoid
mesiodistally
Similar to maxillary CI
but smaller
2 or no pulp horn
Broader mesiodistally
Root canal Usually 1 root 1canal
(99.4%), 2 canal(0.6%)
Centrally located, conical
in shape
Lateral canal: 20%
Usually 1 root 1canal
De Deus(1992)- 3% with
2 root canal, Walvekar
(1997): 3 root canal
Lateral canal: 24%
Cross-section Cervical:
triangular(young),
oval(old),Middle: ovoid
Apical : round
Cervical:
ovoid(labiopalatally)
Middle: ovoid
Apical : round

MAXILLARY
CENTRAL INCISOR
MAXILLARY
LATERAL INCISOR
Others Root curvature: 75%-
straight
Distal -8%, Mesial -4%
Labial -9%, Lingual-4%
Root: deflected palatal &
distal(more than 50%)
Clinical significance Access cavity: Triangular
to slightly oval
Removal of lingual
shoulder
Access outline: more
oval as tooth matures
Labial Perforation:
common
Access cavity too far
palatally: Straight line
access difficult
Access cavity: Smaller
Gemination, fusion
concrescence, dens
invaginatus, talon’s cusp,
microdontia : common.
Removal of cervical
constriction
Lateral canals: more
common
Labial perforation: Most
common

Average
tooth
length(mm)
Pulp
chamber
Root canal Cross-
section
Others
26.5 Largest of all
single rooted
teeth
Wider
labiolingually
No pulp horn
Labiopalatally
: triangular &
mesiodistally:
narrow &
resembles
flame
Usually 1 root
1canal:96.5%,
2 or more
canal:
3.5%(wider
labiopalatally)
One pulp horn
Lateral canal:
30%
Apical foramen
centrally at
anatomic apex
in 14% cases
Cervical:
oval
Middle: oval
Apical :
constricted
Root: distally,
Bifidity(rare)
39% straight
root,32%
distal,7%
bayonet, 2%
dilacerated,
13% labial
MAXILLARY CANINE

+ Access cavity: Oval( greater diameter labiopalatally)
+ Fenestration common, apical curettage difficult
+ Surgical access difficult: long root
+ 30% root: distal curve
+ Abscess in maxillary canine: perforates labial cortical plate
below insertion of levator muscles of upper lip and drains in
buccal vestibule
+ Perforation above insertion of levator muscles of lip: drainage
of abscess in canine space resulting in cellulitis
Cohen’s Pathways of pulp, 8th edition

MAXILLARY 1ST
PREMOLAR
MAXILLARY 2ND
PREMOLAR
Average tooth length 20.6 21.5
Pulp chamber Wider B-P(ovoid)
2 pulp horns
Roof: coronal to cervical
line & floor: below
cervical line
More wider B-P
2 pulp horn
Roof: Deeper than 1st
Pulp chamber deeper if 2
canals present
Root canal 2 roots: 54.6%
21.9%-separated
&32.7%-partially fused
2 canals at apex-29%
Palatal canal: larger
below palatal cusp &
buccal canal below
buccal cusp
Lateral canal:49.5%
Single root: 90.3%
Partially fused: 7.7%
1 canal at apex: 75%
2 canals: separate or
converge at apex
Majority of canals:
curved only 9% straight
Lateral canal: 59.5%

MAXILLARY 1ST
PREMOLAR
MAXILLARY 2ND
PREMOLAR
Others Root: Straight: 38%,
Distal:36%,
Buccal:14%, Palatal:2%,
Double rooted:
Buccal-Palatal & straight
common
Palatal-Straight & buccal
curve common
Apical foramen on lateral
root surface:78%
(Guttman)
Distal curve of root:
27%, Bayonet curve:
20.6%
Clinical significance 2 canal: A/O-oval or slot
3 canal: triangular base
towards buccal
Maxillary sinus floor:
consider
Surgical procedure:
Palatal root difficult to
reach
Access cavity design: 1
canal- B-L width
corresponds to buccal &
palatal pulp horn, 2
canal-identical to 1st PM,
3 canal- triangular
Narrow ribbon likecanal:
Difficult to obturate
1 canal: Orifice indistinct

 Average tooth length: 20.8 mm
 Largest pulp chamber
 4 pulp horns: MB,DB,MP,DP
 Pulpal roof: rhomboidal, floor: traingular
 Palatal orifice: Largest, oval
 MB orifice: Below MB cusp, long buccopalatally
 DB orifice: Distal & Palatal to MB orifice, accessible
from mesial

 MB root: broad buccopalatally, distal
curve-78%
 DB: small, almost round, 54% straight,
17% mesial, 19% distal & 10% S or
bayonet shaped
 Palatal: largest & longest, flat ribbon
like wider mesiodistally, 40% straight,
55% buccally, lateral canal in 40%
 Oswald(1979)- Curvature in palatal
canal is so common that it should be
assumed that the curve is present
unless proved otherwise

 Ingle(2002): 3 canal in 41.1%, 4 canal in 56.5% and 2 canal in
2.4%
 MB: narrowest
 MB2-51.5-95.2% in vitro studies & 18.6-77.2% in vivo studies
On avg. MB2: 1.8 mm away from MB canal in Palatomesial
direction
 DB: single narrow taperiang, round at apical third
 Palatal canal: Ovoid mesiodistally, at apex round
 Buccal curvature: 85%, Curve to buccal and to palatal: 13%

 Access cavity: Traingular, MB2 canal- Cloverleaf appearance
or Shamrock preparation(Luebke)
 MB2 canal(troughing & countersinking by ultrasonic tips):
from distopalatal angle as initial canal curvature is mesial
 Buccal curvature of palatal canal: may not be visible on
radiograph
 Isthmus: Between MB canals (sometimes)
 Close to sinus floor

NON- NEGOTIABLE MB2 CANAL:
Narrow, Diffuse calcification, Pulp stones,Tortuous pathway
IDENTIFICATION
+ Piezoelectric ultrasonics
+ Dyes: Methylene blue, Chinese red
+ Bubble test
+ Fiberoptics
+ Explorer
+ Red Line Test
+ Magnification
+ Radiograph: If in WL film, file not centered in dimensions
of root, presence of another canal
Shetty K, Yadav A, Babu VM. Endodontic management of maxillary first molar having five root canals with
the aid of spiral computed tomography. Saudi Endodontic Journal. 2014 Sep 1;4(3):149.

Shetty H, Sontakke S, Karjodkar F, Gupta P, Mandwe A, Banga KS. A Cone Beam Computed Tomography (CBCT)
evaluation of MB2 canals in endodontically treated permanent maxillary molars. A retrospective study in Indian
population. Journal of clinical and experimental dentistry. 2017 Jan;9(1):e51.

Case reports of number of root canals in permanent maxillary
first molar and method used to identify canals

 Tooth length: 20mm
 Pulp chamber: similar to 1st molar, narrower MD
 Roof: rhomboidal, floor: obtuse traingular
 Sometimes all 3 canals in straight line
 Greater incidence: root fusion and C shaped canal
 Root canals: Less divergent, fewer lateral canals

 Palatal root: straight and 37% buccal
curve
 MB root: distal curve, 22% straight
 Distal root: straight, 17% mesial curve
Usually 3 canal
 Fused buccal root: 2 canal
 1 conical root: 1 canal
 16% apical foramen centrally located
 MB orifice: more mesial and buccal
than first molar

 Access cavity
 4: rhomboidal, 3: traingular, 2: ovoid wider buccopalatally
 To enhance radiographic visibility: A more perpendicular and
distoangular radiograph
 Closer to maxillary sinus than 1st molar

 Pulp chamber: similar to 2nd molar
 Cases of 4 to 5 root canal orifice or conical chamber with 1 root
canal
 3 well developed roots, may be fused, 1-4 or more roots
 Root canal: 1 to 4 or in rare cases 5, C shpaed canal
 Close to maxillary sinus and tuberosity

MANDIBULAR
CENTRAL INCISOR
MANDIBULAR
LATERAL INCISOR
Pulp chamber Small, flat mesiodistally
3 pulp horns(young
tooth)
Wide labiolingually
larger dimension
Root canal 1 flat root, narrow
mesiodistally wide
labiolingually
1 canal 1
foramina:70%
2 canal, 1 foramen:5%,
1-2-1: 22%,
2 canal 2 foramen: 3%
Root: Larger than central
incisor
Straight, distally or
labially curved
1 canal,1 foramen:
56.9%, 2-1: 14.7%, 2
canal 2 foramen: 13.9%

MANDIBULAR
CENTRAL INCISOR
MANDIBULAR
LATERAL INCISOR
Others Cervical: ovoid
Middle: ribbon
shaped(labiolingual)
Apical : round
Lateral canals: 20%
Apical foramen at center
of root: 25%
Isthmus: 20% of teeth
at 1mm level, 30% at
2mm,55% at 3 mm
(Mauger &
Schindler,1998)
Lateral canals: 20%
Apical foramen at center
of root: 20%

+ Access cavity: Long oval
+ 2 canals: may not be appreciated on radiograph
+ 2nd canal: Usually lingual to main canal
+ Surgical access: Difficult
+ Removal of lingual shoulder,
+ Gemination & fusion common

Average
tooth length
Pulp chamber Root canal Cross-section Others
23mm Similar to
maxillary
canine but
small in
dimension
Narrow
mesiodistally
Only 1 pulp
horn in adults
Cervical
constriction
Single root but
2.3% cases: 2
roots and 2
canal
1 canal: 78%,
2-1: 5%, 1-2-1:
18%, 2 canal 2
foramen:2%
1 root canal:
broad in
middle third
followed by
constriction
Cervical:
ovoid,
middle:
ovoid, apical:
round
68%: straight
root, 20%
distal curve
Lateral
canals: 30%
Apical
foramen at
center: 30%
C/S:Removal of
lingual
shoulder: to
gain access to
2nd canal
MANDIBULAR CANINE

+ Access cavity: Oval
+ Old patient: secondary dentin deposition- Incorporation of
incisal edge for straight line access

MANDIBULAR 1ST
PREMOLAR
MANDIBULAR 2ND
PREMOLAR
Pulp chamber MD width: narrow
Prominent buccal horn
Small lingual pulp horn
Crown tilt: 300
Similar to 1st premolar,
Lingual pulp horn more
prominent under well
developed lingual cusp
Root canal Short conical root, apical
third may divide into 2
or 3 roots
1 canal 1 foramen:
70%,
1-2-1: 4%,
1-2: 24%, 2 canal 2
foramen: 1.5%, 3-2: 2%
1 root, very rarely 2 or 3
roots
1canal 1
foramen:97.5%, 1-2:
2.5%
Root curvature: distal-
40%, straight-39%

MANDIBULAR 1ST
PREMOLAR
MANDIBULAR 2ND
PREMOLAR
Others Cervical: ovoid,
middle: ovoid, apical:
round
48% root: straight, 35%
distal
Lateral canal: 44.3%
Apical foramen at apex:
15%

MANDIBULAR 1ST PREMOLAR
MANDIBULAR 2ND PREMOLAR

+ Acess cavity: oval(wider mesiodistally), extends on cusp tip to
gain straight line access
+ Close to mental nerve
+ Distal tilt: Angulation of bur

 Pulp chamber: roof-rectangular, floor-rhomboidal
 4 pulp horns
 Roof: cervical third just above cervix
 Floor: Cervical third of root
 3 orifice: MB, ML, D

 MB orifice: Below MB cusp
 ML orifice: Depression formed by mesial and lingual wall, A
groove usually connects MB and ML orifice
 Distal: oval, widest dia buccolingually, distal to buccal groove
 2 roots: Wide and flat buccolingually
 3 roots: few cases, either mesial or distal, known as RADIX
ENTOMOLARIS in Eurasian and Indian population(less
than 5% cases)

 Mesial root: 2 canal 2 foramen: 41%, 2-1 : 28%, 2-1-2 : 10%, 1
canal 1 foramen: 12%, 1-2 : 8%
 Distal root: 1 canal 1 foramen: 70%, 1-2 : 8%, 2-1: 15%, 2 canal
2 foramen: 5%
 Mesial root: distally curve in 84% cases
 Distal root: straight
 Lateral canal: 23% in furcation area, 45% in mesial root & 30%
in distal root

+ Access cavity: Trapezoidal or rhomboidal
+ C shaped canal
+ Overenlargement of mesial canals: avoided

Bansal R, Hegde S, Astekar M. Morphology and prevalence of middle canals in the mandibular molars: A

+ Below dentinal projection in the groove between 2 main
canals
+ Layer of dentin in groove: lighter
+ Average length of groove: 1.07-2.81mm
+ Average depth: 1.05
+ Sherwani et al(2016): 67% cases in indian population,middle
mesial canal in the center, 20% closer to ML and 12% to MB
Chavda SM, Garg SA. Advanced methods for identification of middle mesial canal in mandibular molars: An in
vitro study. Endodontology. 2016 Jul 1;28(2):92.

 Tooth length: 19.8mm
 Pulp chamber: smaller
 Root canal orifices: smaller & closer together
 Roots: 2 in 71% cases, 1 in 27% and 3 in 2% cases
 Lateral canals: Mesial root-45% and distal root-34%,
Furcation area-11%

 3 root canals, most frequent variation: 2 canals
 All 3 canals are small and ovoid in cervical and middle third
and round in apical third
CLINICAL SIGNIFICANCE
C shaped canal
May be only one mesial canal

+ Tooth length: 18.5mm
+ Pulp chamber: similar to 1st and 2nd molar, Large and possess
many anamolous configuration
+ 2 roots 2 canal, occasionally 1 root 1 canal or 3 root 3 canal
CLINICAL SIGNIFICANCE
Anatomy: unpredictable
Varying access preparation shape
Alveolar socket: may project onto lingual plate of the
mandible

STRUCTURE OF DECIDUOUS AND
PERMANENT PULP
PULP
CHAMBER
PULPAL
OUTLINE
PULP
HORNS
Larger in comparison to
crown
Follows DEJ more closely
Closer to outer surface
Smaller in comparison to
crown
Follows DEJ less closely
Away from outer surface
DECIDUOUS PERMANENT

STRUCTURE OF DECIDUOUS AND
PERMANENT PULP
PULP
CHAMBER
ROOT
CANAL
BLOOD
SUPPLY
Porous, presence of
accessory canal
Ribbon like
Enlarged apical foramen,
thus abundant blood supply
Less accessory canal
Well defined, less branching
Foramens are restricted,
reduced blood supply
favours calcific response
DECIDUOUS PERMANENT

+ The cause of most endodontic failure is inadequate
biomechanical preparation of root canal system.
+ This can be due to inadequate knowledge of root
canal anatomy.
+ Therefore, the only way to provide the best
environment for success is to have thorough
knowledge about the root canal system along with its
variations.

+ The cause of most endodontic failure is inadequate
biomechanical preparation of root canal system
+ This can be due to inadequate knowledge of root
canal anatomy
+ A systemic knowledge of pulp chamber floor
anatomy can provide greater certainty about the
total number of root canal in a particular tooth.
+ Therefore, the only way to provide the best
environment for success is to have thorough
knowledge about the root canal system along with its
variations

+ Describe in detail internal anatomy of maxillary 1st
and 2nd molar
+ Describe in detail internal anatomy of mandibular 1st
and 2nd molar
+ Internal anatomy of permanent teeth and its clinical
significance in restorative dentistry and endodontics
+ Describe structure of root apex and clinical
significance
+ Management of curved canal
+ Management of calcified canal

1. Diwan A, Sreedevi CR, Nagaraj T, Raghava V, Sinha P, Moushmi CB.
Determination of internal anatomy of a permanent dentition: A review. Int J
2. Endodontic Science, Carlos Estrela, Volume 1 , 2nd edition.Page-531-563
3. Krasner P, Rankow HJ. Anatomy of the pulp-chamber floor. Journal of
endodontics. 2004 Jan 1;30(1):5-16.
4. Goto G, Zhang Y. Study of cervical pulp horns in human primary molars. The
Journal of clinical pediatric dentistry. 1995;20(1):41-4.
5. Bansal R, Hegde S, Astekar M. Classification of Root Canal Configurations: A
Review and a New Proposal of Nomenclature System for Root Canal
6. Ahmed HM, Versiani MA, De‐Deus G, Dummer PM. A new system for
classifying root and root canal morphology. International endodontic journal.
2017 Aug;50(8):761-70.
7. Alothmani OS, Chandler NP, Friedlander LT. The anatomy of the root apex: A
review and clinical considerations in endodontics. Saudi Endodontic Journal.
2013 Jan 1;3(1):1.

8. Ahmed HM, Neelakantan P, Dummer PM. A new system for classifying
accessory canal morphology. International endodontic journal. 2018 Feb
1;51(2):164-76.
9. Balani P, Niazi F, Rashid H. A brief review of the methods used to determine the
curvature of root canals. Journal of Restorative Dentistry. 2015 Sep 1;3(3):57.
10. Green D.A stereo-binocular microscopic study of the root apices and
surrounding areas of 100 mandibular molars.Oral Surg Oral Med Oral Pathol
1955;8:1298–1304.
11. Green D.A stereomicroscopic study of the root apices of 400 maxillary and
mandibular anterior teeth. Oral Surg Oral Med Oral Pathol 1956;9:1224–32.
12. Green D. Stereomicroscopic study of 700 root apices of maxillary and
mandibular posterior teeth. Oral Surg Oral Med Oral Pathol 1960;13:728–33.
13. Cooke HG, Cox FL. C-shaped canal configurations in mandibular molars. The
Journal of the American Dental Association. 1979 Nov 1;99(5):836-9.
14. Fernandes M, De Ataide I, Wagle R. C-shaped root canal configuration: A
review of literature. Journal of conservative dentistry: JCD. 2014 Jul;17(4):312.
15. Mahendra L, Govindarajan S, Jayanandan M, Shamsudeen SM, Kumar N,
Madasamy R. Complete bilateral gemination of maxillary incisors with separate
root canals. Case reports in dentistry. 2014;2014

16. Chipashvili N, Vadachkoria D, Beshkenadze E. Gemination or fusion?-
challenge for dental practitioners (case study). Georgian Med News. 2011
May;194:28-33.
17. Law L, Fishelberg G, Skribner JE, Lin LM. Endodontic treatment of
mandibular molars with concrescence. Journal of Endodontics. 1994 Nov
1;20(11):562-4.
18. Jafarzadeh H, Azarpazhooh A, Mayhall JT. Taurodontism: a review of the
condition and endodontic treatment challenges. International endodontic
journal. 2008 May;41(5):375-88.
19. Chowdappa NS, Hegde MN, Shetty S, Bhat GT. " Management of
taurodont right mandibular second molar tooth": A case report. Journal of
Indian Academy of Dental Specialist Researchers. 2014 Jul 1;1(2):80.
20. Jafarzadeh H, Abbott PV. Dilaceration: review of an endodontic challenge.
Journal of endodontics. 2007 Sep 1;33(9):1025-30.
21. Yeh PY, Pai SF, Lee YY, Yang SF. Dentinogenesis imperfecta: a challenge
for root canal treatment-case report. Journal of Dental Sciences. 2008 Jun
1;3(2):117-22.

23. Gallacher A, Ali R, Bhakta S. Dens invaginatus: diagnosis and
management strategies. British dental journal. 2016 Oct;221(7):383
24. Ayer A, Vikram M, Suwal P. Dens evaginatus: a problem-based approach.
Case reports in dentistry. 2015;2015.
25. Sakkir N, Thaha KA, Nair MG, Joseph S, Christalin R. Management of
Dilacerated and S-shaped Root Canals-An Endodontist’s Challenge.
26. Kothari H. Calcified Canals–A Review.IOSR Journal of Dental and
Medical Sciences.2014;13(5):38-43.
27. Mittal S, Kumar T, Mittal S, Sharma J. “Internal root resorption: An
endodontic challenge”: A case series. Journal of conservative dentistry:
JCD. 2014 Nov;17(6):590.
28. Hegde N, Hegde MN. Internal and external root resorption management: a
report of two cases. International journal of clinical pediatric dentistry.
2013 Jan;6(1):44.

Internal anatomy of pulp space

Internal anatomy of pulp space

More Related Content

What's hot

Similar to Internal anatomy of pulp space

More from MrinaliniDr

Recently uploaded

Internal anatomy of pulp space

Editor's Notes