Transcript kda--curved canals 2014

BDS(NBI), CIBRD(KASADA), MDSc-Endo(Mal),
Cert. In Oral Implantology (Mal)
SPECIALIST ENDODONTIST,IMPLANT
PRACTITIONER AND LECTURER
Dept of Conservative Dentistry
University of Nairobi
Practice limited to Endodontics and implantology
E-Mail: [email protected] or
[email protected]
Introduction and Lit review

The goal of endodontic therapy is the prevention
and/or elimination of pathosis of endodontic origin
Correct diagnosis
SUCCESFULL
RCT
Complete obturation
Cleaning and
Debridement
(European Society of Endodontology Consensus, 1994, Omer et al., 2004, , FDI World
Dental Press, 2005 ).
Introduction and Lit Review cont..
Detailed Knowledge of ROOT
CANAL SYSTEM
Inadequate understanding
Of Root Canal
Systems
Improper shaping
And
Inadequate Cleaning
SUCCESSFUL ROOT
CANAL
Poor Obturation
Omer et al.,2004,Mikrogeorgis
et al.,1999,Al-Nazhan,2007
Treatment
Failure
Carrotte,2004
INTRODUCTION CONT..
A tooth with a straight root and a
straight root canal is an exception
rather than being normal because
most teeth show some curvature of
the canal
(weinne,scheinder,kyomin).
Tomes, in 1848, called such
curvatures as dilacerations
Dilaceration:
Defination

It refers to an angulation or a bend
or a curve in the root or crown of
formed tooth or a deviation or in the
linear relationship of a crown of a
tooth to its root.
Epidemiology
In most studies,prevalence of
curvature ranged between 80 to
100%. Dienya et al 2009 in a study
of 400 maxillary and mandibular 1st
molars in a Kenyan population got
91% curvature.
Dr Schaffer in Germany examined
1163 root canals and found that 980
(84%) were curved and 65% showed
an angle > 27 degrees with radii <
40 mm.
CAUSE


The condition is thought to be
due to trauma during the period
in which tooth is forming.
The result is that the position of
the calcified portion of the tooth
is changed and the remainder of
the tooth is formed at an angle
Types of curvatures
Curved canals can be:
 Gradual curvature of the canals
in the coronal,middle or apical
third;
 Acute curvature in the apical
third;
 Curvature throughout the canal;
 S-shaped root canal.
Mandibular 1st molar with GRADUAL
distal curvature of the mesial root
Maxillary molar with the DB root showing
ACUTE curvature in the apical third
Buccal curvature at the tip of a palatal root
Mandibular 1st molar with an S-curvature of the
D root
Combination of S-shaped canals and gradual
shape
THE STAIR CASE CURVE
THE DECEIVING CURVE --distal root curves lingually
THE CONSEQUENCES
1) EXCESSIVE FLARING
2) LEDGING
3) APICAL TRANSPORTATION
4) APICAL PERFORATION
SHORT OBTURATION- due to
inability to negotiate curvature
Common to all curvatures:
• Instruments break
unexpectedly
• Separated apical part
is difficult to remove
Instruments separation just
at the beginning of the curve
Missed canal in maxillary 1st
molars
Note : Canal was missed probably due to it being
hidden at the beginning of the curve
presence of lamina dura—indicates canal presence
pain
Management

Start with accurate diagnosis
preoperative radiographs taken with
parallelling technique with at least
two different views-SLOB RULE:
UPPER TEETH-normal buccal
view,then use rule MMMM
LOWER TEETH—normal buccal
view then use the rule DMMD or
use CBCT OR DIGITAL X-RAYS
Paralleling technique in the lower
jaw
Parallel periapicals
Root canal configurations obtained with
CBCT
Type I
Type V
Type II
Type VI
Type III
Additional
Canals 1
Addition
al canal
2
Type IV
Additiona
l Canal 3
Make a good access cavity
Pitfalls of inadequate access
Inadequate acess easily
leads to ledging
Remnants of pulp
roof removed by
slow speed round
bur
Straight line
access
achieved
Determine the DEGREE OF curvature
Before initiation of treatment, an estimate should
be made as to the degree of curvature of canals
by seeing the radiograph, probing OR
schneiders method
The interior angle is formed by intersection of
the straight line from the orifice through coronal
portion of the root and another straight line
from apex through apical portion of canal
Take an impression of the
canal
S-shaped
c-shaped
J--shaped
Merging canals
USE CROWN DOWN
TECHNIQUE
Divide the root into three
Flare coronal one third and
open up orifice-use orifice
shapers
Or 25/07 in mtwo system or sx in protaper system—Do
not use gates glidden.
ENDOFLARE
1
Before ENDOFLARE®
filing - Pronounced
dentinal overhang
2
ENDOFLARE® filing
(penetration < coronal
third)
3
After ENDOFLARE® filing
- Elimination of the coronal
strains
BEFORE
AFTER
Pr. CALAS
Working length
Working length-practical
determination

Use apex
locators—such as
raypex 6 or vdw
motor
No direct measurements on file
Direct measurements are likely to introduce
errors
MEASURE CURVATURE by
tracing
rules





R>160------stainless steel handfiles can be
used
R—140—160---consider precurving stainless
steel files or use rotary
R –100—140—rotary with initial glide
path;use highly flexible files with radial
lands or use rotary in straight portion and
hand files apically
R –90—100—niti hand files with high
flexibility; orifice shapers only coronally
R—90 or less—consider apicoectomy and
reverse filling,aggressive use of hand niti
management
USE OF HAND NITI FILES
Tedious..some files can break due to torsional stress
PRECURVING STAINLESS STEEL FILES
Crown Down Technique
Crown Down Technique



Coronal third
Middle third
Apical third
Orifice shapers
0.06 taper rotary
0.04 OR 0.02 taper hand or rotary
FILES TO USE
HERO Shapers
Red sequence
Red sequence for average difficult cases
25 6%
2/3
WL
25 4%
WL
30 4%
WL
2/3 WL
WL
+
+
HERO Shaper
Yellow sequence
HERO Shaper
Yellow sequence
Yellow sequence for difficult cases
20 6%
20 4%
25 4%
30 4%
2/3
WL
WL
WL
WL
2/3 WL
WL
+ + +
Preparation of coronal third
Preparation of middle third
Preparation of the apical third


Prepare to actual working length
Use 0.04 taper NiTi hand files in
sequence smaller to larger
Preparation of apical third
Irrigation needle should have side opening to
opening to preven driping of irrigant fluid hence
pain
Acoustic streaming around a file in free water (left) and a schematic drawing
(right).
cases
Extensive Amalgams-can be very
painful necessitating endo-therapy