It is time to change in

Endodontics

Prof. Dr. Hussain F. Al-Huwaizi

Until now, dentists in Iraq use the standardized intracanal instruments (reamers, and files) and rarely use the rotary instruments. This is due to many reasons as:

1-                 Lack of knowledge about the new system.

2-                 Difficulty to buy them (as they are not present in Iraq)

3-                 Fear from not mastering the system.

4-                 Fear from increase of cost of treatment on the patient.

Drawbacks of the standardized intracanal instruments

1-                 Different tapering from that of the root canal.

2-                 Too many instruments are needed to clean the root canal.

3-                 They need a time consuming and difficult technique (flaring technique) which

4-                 They are made of rigid material causing distortion to the root canal anatomy.

Why the rotary instruments were constructed

1-                 Now they are made of super elastic alloy (nickel titanium) which can enter severely curved root canals.

2-        They resemble the taper of the root canal.

3-                 They are fewer in number ( a root canal can be cleaned by 3-4 instruments)

4-                 They use the crown down instrumentation technique (cleaning coronal part of root canal then the going apically).

5-                 They clean the root canals much faster than the traditional techniques.

            Types of rotary instrumentation systems

Examples of rotary instrumentation systems

1- Profile GT system

This system consists of different sizes that resemble the traditional standardized instruments with different tapers ex.

Size 20 with taper 10%

             with taper 8%

             with taper 6%

             with taper 4%

   These instruments have one taper and they are more tapered than the standardized instruments which have a taper of 2%. 

2- The Protaper rotary instrumentation system

This system is designed to manufacture an instrument with variable tapering. Under use file blades engage smaller area of dentin that will reduce fatigue and separation of the instrument.

This system is specifically designed to instrument difficult, highly calcified and severely curved root canals. The progressive taper advanced flute design

provides the flexibility and efficiency

to achieve consistent successful

cleaning and shaping when faced with these challenges.

The system consists of:

1-      Shaping file (SX):

This is an auxiliary instrument used mainly in short canals and opening the orifice coronally.

 It opens the orifices to allow easier access to the apical part of the root canal.

The taper of the instrument increase greatly from D0 to D9.

2-         Shaping files (S1 and S2):

These instruments have increasingly larger tapers over the length of their cutting blades allowing each instrument to engage, cut and prepare a specific area of the canal.

a)                  S1. D0 has a size of 0.17 mm and is designed to prepare the coronal third of the canal.

b)                  S2. D0 has a size of 0.2 mm and is designed to prepare the middle third of the canal.

3-      Finishing files:

These instruments were designed to prepare the apical third of the canal. Tapering range from D0 to D3 at rate of 0.07, 0.08, 0.09 mm/m from D4-D14 tapering decrease to improve flexibility.

There are three instruments F1, F2, and F3.

Advantages:

1-     Multiple taper designs improve flexibility and curving efficiency.

2-     Balanced pitch and helical angle optimize cutting action with debris removal coronally also it prevents instrument from screwing into the canal.

3-     Both shapers and finishers prepare smooth continuous taper.

4-     Triangular cross section increase safety, cutting efficiency and tactile sensation also reducing lateral contact area between the file and dentin.

5-     Modified guiding tip prevents gauging side wall of the canal. 

6-     Fewer instruments to complete preparation

7-      Less time to prepare the entire canal

8-     High cutting efficiency

9-