Good morning

Root Canal Preparation Techniques

Dr. Ali Hani Hassan

The principles of root canal preparation are to remove allorganic debris and microorganisms and to shape the wallsof the root canal so that the entire root canal space may beobturated

The root canal filling material of choice is gutta-percha,which requires a gradual even funnel-shaped preparationwith the wides part coronally and the narrowest part 1.0mm short of the root apex

Canal enlargement procedures

The standardized procedure (conventional technique)

• This technique was used for many years and

instrument, file or reamer, to be placed to the full

working length.

• The canal was enlarged until clean white dentin

shaving were seen on the apical few millimeters of the

instrument.

• The filing was continued for a further 2 or 3 sizes, to

complete the preparation.

1) As This method was satisfactory in straight canals, but was quite

unsuitable for curved canals.

2) the instrument sizes increase, they become less flexible and cause

errors in curved root canals.

3) The common problems are ledging, zipping, elbow formation,

perforation and loss of working length owning to impaction of dentin

debris.

Disadvantages:

Flaringtechniques

Apical tocoronal

Coronal toapical

1- The smaller, more flexible files are used in apical portion, and the stiffer files

need not be forced but are used short of the apex.

2- More apical dentin is available for the dentin matrix,

3- In curved canals, files are more effective and may retain original canal shape

better.

4- the intracanal irrigant have more room to gain access to the irritants and

necrotic debris.

5- easier placement for finger spreaders and gutta-percha cones.6- The desired shape of the canal preparation is obtained,

The flared preparation has several physical advantages:-The flared preparation has several physical advantages:-

Step-back technique:-In this technique, we usually prepare the apical part with flexible instruments (i.e. small sizes, 10, 15, 20, 25,

30), but sizes beyond size 30 are considered as a non-flexible instruments.

The first step in this technique is the selection and determination of initial size of instrument according to width ofapical third

Initial size:Is the first instrument, which is inserted inside the canal and goes to the full length and has slight engagement to thewalls.

Recapitulation: - is to ensure that the canal is remained patent.

It is mean shaping the coronal aspect of a root canal first before apical instrumentation commenced.

Step down technique (Crown down technique):-

Gates Glidden drill

1. the technique permits straighter access to the apical region,

2. it eliminates coronal interferences,

3. it removes the bulk of tissue and microorganisms before apical shaping,

4. it allows deeper penetration of irrigants,and the WL is less likely to change.

Advantages:

Balanced force technique

Thank you