root canal enlargement techniques -...
TRANSCRIPT
Hand and rotary root
canal enlargement
techniques
For IV. years students
Dr. Juhász Alexander
Design objectives of root
canal preparation I. Continuously tapering funnel from the apex to the
access cavity.
II. Cross-sectional diameter should be narrower at
every point apically.
III. The root canal preparation should flow with the
shape of the original canal.
IV. The apical foramen should remain in its original
position.
V. The apical opening should be kept as small as
practical.
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Advantages of orifice enlargement • Effectively, ⇓ the curvature in the coronal part of the root
canal, allowing straighter access for files to the apical region.
It therefore reduces the likelihood of apical transportation
(zipping).
• It allows improved access for the flow
of irrigant solution within the canal.
• It reduces the likelihood of apical extrusion
of infected material as most of the canal
debris is removed before apical instrumentation
takes place. This is particularly important
because the majority of bacteria in an infected
root canal are located in the coronal region.
1) Standarized technique.
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Can be use for straight tiny
canal.
Unsuitable for curve canals.
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Balanced force technique
Preparing curved canal.
Roane's Flex-R file with
1. Triangular cross section
2. Clockwise and countclockwise rotational
motion.
Modified cutting tip:
The objective of this special tip design is to
guide the instrument through the curved canal
with minimum alteration of the canal's course
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Rotary techniques
Pro File (Dentsply-Maillefer)
Pro Taper- conicity 2-19%
Pro Taper 250-300 rpm
Pro Taper-apical enlargement
Pro Taper
ProTaper sequences
WL determination
Sx -WL
S1 -WL
S2 -WL
F1 -WL
F2 –WL
Or S1-Sx-S1-S2-F1-F2
Design
S-Shaped Cross-Section
>Reduces the risk of the instrument engaging in the canal
caused by the build up of dentin chips.
minimal radial
contactmaximum space for
dentin removal
Preparation
One Basic Sequence
> Patency to the apex with an ISO 10 C-Pilot
File
> Max. 4 Instruments
> For all types of canal
STEP 1
C-Pilot
ISO 10
STEP 2
Mtwo
10/.04
STEP 3
Mtwo
15/.05
STEP 4
Mtwo
20/.06
STEP 5
Mtwo
25/.06
SIMULTANEOUS SHAPING with 4 instruments