Endodontic Access Flashcards
To Gain Access
to the pulpal
space for:
(3)
- Visualization
- Instrumentation
- Obturation
To Maintain
Strength of the
tooth:
(3)
- Preserve Incisal Edge
- Conserve Marginal Ridges
- Maintain correct Shape, Size & Position
First: Know the Proper Outline Form: ANTERIORS
Maxillary central incisors
are triangular with the base of the triangle toward the incisal edge
First: Know the Proper Outline Form: ANTERIORS
Maxillary lateral incisors
follow the same form but are narrower and less flared incisally
First: Know the Proper Outline Form: ANTERIORS
Maxillary canines
also have the same general form but are closer to an oval
MAXILLARY ANTERIORS
OUTLINE FORM
Triangular to Ovoid
ANTERIORS
The red dots in the center of the access (penetration
points) are where you would generally expect to find the
pulp. Usually in the — mass of the root form.
center
Mandibular central & lateral incisors are very narrow and have 2 canals —% of the time so
the access is very narrow M-D and extends further incisally
40
Mandibular canines are — and similar to maxillary canine access
oval
BEWARE: Mandibular Incisors are VERY
NARROW M-D
BEWARE: Mandibular Incisors are VERY NARROW M-D
We must be AWARE of this to avoid
ruining the tooth by
tipping our access bur to the mesial or distal and drilling
out the side of the tooth
We must VISUALIZE the angulation of the unseen root in
both
M-D and B-L directions
MANDIBULAR ANTERIORS:
Triangular to oval
Crucial to have a — understanding of
the tooth/pulp you are attempting to access
visual and spatial
Don’t ever look for the canals with the —
bur
Don’t expect to always feel a “—” into the
pulp chamber
drop
You will find the — of the pulp chamber first
roof
Make a mark on your entry bur at
7 mm.
Mark your ACCESS bur at 7 mm.
Use a permanent marker:
IF you don’t know for certain where you are:
(3)
STOP & TAKE A RADIOGRAPH
*Have someone else take a look
*Don’t become DISORIENTATED
Access: Maxillary Central Incisor
*Triangular access (base of
triangle at incisal)
“Incisal compromise”
Total straight-line access on anteriors would involve access from the facial and create a weakening of the incisal edge and an esthetic issue.***
Base of triangle parallels
incisal edge with NO
gouging of surface to
incisal of base of ▲
Angles of triangle
are slightly
rounded.
M&D Marginal
Ridges are
not invaded
or weakened
About 3 mm. on all sides
of access 14
Pulp Horns and
chamber are free
of tissue and caries
Access: Maxillary Lateral Incisor (use #2 round)
(3)
*Triangular/Oval Access
*Thinner root than central (narrower access M-D narrower pulp horns)
*“Incisal Compromise” on all anterior teeth
Access: Maxillary Canine Use #2 or #4 round bur
(4)
*Oval access
*Canal narrower M-D than F-L
*One root (larger and longer
than lateral)
*USUALLY SINGLE CANAL
(most max. anteriors)
Access: Mandibular Incisors
Oval access (use #2 round bur)
(5)
*Root wider F-L than M-D
*Very narrow M-D (easy to perforate to side
of root)
*One canal 60% Two canals 40%
*When two canals-mostly Type II (See
Weine)
*Cervical access will miss Lingual canal
Mandibular lateral incisor
— % two root canals
44
Premolar Access: Planning for success
*Type I:
*Type II:
*Type III:
*Type IV:
one canal from
pulp chamber to apex
2 canals from
pulp chamber, join prior
to apex
2 canals from
pulp chamber to apex
one canal from
pulp chamber divides
prior to apex (most
difficult to treat)
Maxillary first premolars have a B. & a L. canal in at
least —% of cases.
85
M-D width of the access is no
wider than a #4 round bur and the opening usually
extends from near the tip of the buccal cusp lingually
Maxillary second premolars contain a second canal in
at least —% of cases and the access form is very
similar to the first PM. If there is a single canal, it is
35
centrally located and wide from B to L.
All premolars are very easy to perforate to the mesial or distal! Use — bur and align carefully with root
angulation.
2
Access: Maxillary 1st Premolar
***Access always gained through the
occlusal
approach on all posterior teeth.
Access: Maxillary 1st Premolar
(4)
Thin Oval Access (width of #4)
Thin M-D root
Two canals most prevalent
Canal orifices lie under respective cusp tips
Access: Maxillary 1st Premolar
Two canals most prevalent
–% two canals
–% one canal
–% three canals
85
9
6
Access: Maxillary 1st Premolar
Most Common Error
Not totally unroofed
An Ideal Maxillary 1st Premolar Access:
(3)
Use a #2
round bur
remove pulpal
roof
finish with
ENDO-Z bur
An Ideal Maxillary 1st Premolar Access:
FINAL WIDTH OF ACCESS IS NO WIDER THAN #— ROUND BUR
4
2nd maxillary premolar
— % two canals
23
Access: Maxillary Second Premolar
Access:
Slightly less F-L extension than 1st
Most often Type
2 roots (—%)
3 roots very rarely
If one canal found but not in center F-L,
Beware Type IV, very hard to shape, clean and fill
Thin oval (width of #4)
I 1 root 1 canal (75-85%); Type II, III & IV less frequently
15 -25
there are
probably 2 canals
Access: Maxillary Second Premolar
M-D width =
Use #— round bur to keep small
4 Round Bur
2
First: Know the Proper “Outline Form” PREMOLARS
Mandibular PMs also have a very narrow — width and access
extends from
2 canals in mandibular PMs are somewhat rare and very difficult.
M-D
near the tip of the buccal cusp lingually.
Beware: 2nd canals can occur in
both mandibular canals (look for 4 PDLs
and/or a “fast-break” or “fuzzy” canal somewhere in the mid-root
Access: Mandibular First Premolar
Access:
Usually one root, 1 canal
(type I), — %
Type III, — %***
Three canals less than — %
thin oval
73.5
19.5
1
Don’t Forget: “The Law of Color Change”
The color of the pulp chamber
is always darker than the surrounding walls.
law of centrality
pulp chamber in the center of the tooth
law of concentricity
walls of the pulp cahmber are always concentric to the external surface
law of concentricity
walls of the pulp cahmber are always concentric to the external surface law of the
law of concentricity
walls of the pulp chamber are always concentric to the external surface law of the
law of the CEJ
CEJ is the most consistent landmark for locating the position of the pulp chamber
— RCT is monumentally
more difficult than anteriors
and PM
MOLAR
MOLAR RCT is monumentally
more difficult than anteriors
and PM
why? (2)
Attention to detail is much
more complicated and
compacted into a smaller
area
Many new opportunities to
mess up are presented
— mm. mark
on bur***
7
why mark 7mm?
so you dont perforate!!!!!
OUTLINE FORM: FIRST MANDIBULAR MOLAR
Some texts recommend a triangular access.
However,
in view of the common probability of 2
distal canals (30%), we feel the wisest plan is to
use the TRAPEZOIDAL FORM with rounded angles
as shown.
OUTLINE FORM: FIRST MANDIBULAR MOLAR
why TRAPEZOIDAL FORM?
The wider base of the form is to the Mesial (taking
care to preserve the mesial marginal ridge) and
extending only as far distally as to provide clear
access to the distal canals or canal.
A missed canal is
a failed RCT
OUTLINE FORM: FIRST MANDIBULAR MOLAR
Historically, a — Access (for 3 canals)
and a — Access for 4 canals
Triangular
Trapezoidal
OUTLINE FORM: FIRST MANDIBULAR MOLAR
Historically, a Triangular Access (for 3 canals)
and a Trapezoidal Access for 4 canals - BUT (3)
You often cannot tell if there are 3
or 4 canals in the tooth until you
enter the pulp
You may THINK you have 3 canals but
may NOT find the DL canal until you
open up the access to see.
If it is a singular distal canal, it will be
generally in the center of the form as
illustrated and it may be wide B-L.
OUTLINE FORM: FIRST MANDIBULAR MOLAR
About —% have 2 distal canals so it is
worth looking for them every time.
You will most likely miss the —
30
D-Lingual
“SYMMETRY
RULE”
2-8 % VARIABLE:
A — Canal
between the MB and ML
Or, it could be a Totally
Different animal such as
this “—” canal
Middle Mesial
C-Shaped
The “C-Shaped Canal” tooth contains
3 or more
canals associated by an irregular network of thread-
like canals and areas that are variable in size, shape
and complexity and are extremely difficult to
find and worse to instrument. These are largely seen
in 2nd molars.
Second molars in general are considerably more
difficult than 1st molars which explains why
Advanced Endo does all 2nd molars.
— are very rarely done (Bizarre anatomy,
negligible strategic value and extreme access difficulty)
Third molars
Intelligent CASE SELECTION requires strong consideration for
REFERRAL on
ALL complex teeth
MAXILLARY MOLARSYOUR BIGGEST CHALLENGE :
MB2 CANAL
As often as 95%
As many as —% of Maxillary Molars have 4
canals *
95
This fact makes Maxillary 1st Molars far more
difficult in that the MB2 canal is
minute, dangerous and very
time-consuming to find and to negotiate and to shape.
If you are NOT consistently finding and successfully treating
this MB2 canal, you are doing the patient a disservice and
should STRONGLY CONSIDER
REFERRAL before the
Malpractice Actions begin.HERE is an ACCESS completed in the mouth:
Note how the Endo-Z bur is used to define the
walls as they meet the floor of the prep.
With this ACCESS, it would be EASY to do a
nice OBTURATION of the canals.
If you find placing 3 files in the
canals at the same time for a
radiograph to be difficult . . .
Endodontics is a fairly
simple concept;
EXECUTION is the TRUE
measure of the SKILL OF
THE CLINICIAN
Maxillary Molars are mechanically
difficult as the MB2 canal may require
exceptional skill in locating and
shaping.
MB2 may require as much TIME as all
3 other canals in total !
BE ACUTELY AWARE OF THESE STANDARD VARIATIONS: LOOK FOR THE
MOST COMPLEX VARIATION UNTIL
YOU CAN PROVE IT IS LESS COMPLEX