K files and reamers

2.  In early 1900’s , kerr manufacturing company
designed the k style files and reamers.
 They are endodontic instruments to improve
the efficiency of root canal preparation.
 Files are instruments that enlarge canals with
reciprocal insertion and withdrawal motions.K
files blade angle is sharp and have cutting
edges which make them best suited for cutting
dentin in the filing motion.

3. Reamers cut and enlarge canals with rotational motions.
K-Reamers have a rake angle which makes them most efficient
in rotatory motion.
Reamers are rarely used or indicated.
Disadvantages of reamers include their inflexibility with
increased size ,which can result in wider canal being cut
apically.
Reamers have now been replaced by files.
Originally K type reamers and files are manufctured from round ,
tapered piano wire ( carbon steel ).
Most instruments are now manufactured from a variety of
stainless steel blanks.

4. K - FILES REAMER

5. The stainless steel wire is ground along its long axis into 4 sided
(square cross section ) 0r 3 sided ( Triangular cross section )
tappered shaft that is twisted into flutes extending 16mm from the top
to the tip of the cutting blade.
The traditional reamer is manufactured from a triangular blank ,
File is manufactured from a square blank.

6. The introduction of Nickel - Titanium ( NiTi ) alloy
for manufacturing endodontic instruments has
improved canal shaping due to its improved
flexibility as compared to stainless steel.

8. HEADSTROM FILES
Headstrom files , also known as H files , are
manufactured from a round stainless steel wire
machined to produce spiral flutes resembling cones
or screws .
This instrument has higher cutting efficiency than K
instruments ,but it is fragile and fractures easily .
The better cutting efficiency is attributed to its more
positive rake angle and a blade and a blade with a
cutting rather than a scraping angle .
Hedstrom Files are used for more rapid enlargement
of root canals. Note that the cutting edges are
inclined backwards.

9. The insertion is made easily since
there is no cutting taking place on the
insertion stroke.
When the instrument is withdrawn,
cutting takes place and debris is
carried away from the apex. Use with
an up-and-down motion.

12. 1.REMOVAL OF ALL CARIOUS
TOOTH STRUCTURE
2. CONSERVATION OF
SOUND TOOTH STRUCTURE

13. 4.REMOVAL OF CORONAL
PULP TISSUE ( VITAL AND
NECROTIC )
3. COMPLETE DEROOFING
OF THE PULP CHAMBER

14. 5. LOCATE ALL ROOT CANAL
ORIFICES
6. STRAIGHT LINE ACCESS
TO THE APICAL FORAMEN

16. 1.FRONT SURFACE MOUTH
MIRRORS
2.HANDPIECES

17. 3.BURS

22. MULLER’S BURS LN BURS

23. 4. ENDODONTIC SPOON EXCAVATOR

24. 5. ENDODONTIC EXPLORERS , EG : DG - 16
To identify canal orifices and determine the canal angulation

26. MECHANICAL OBJECTIVES

27. BIOLOGICAL OBJECTIVES