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.

2

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.

4

Can be use for straight tiny

canal.

Unsuitable for curve canals.

5

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

6

7

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