ENDODONTIC INSTRUMENTS : ENDODONTIC INSTRUMENTS Dr. Saurabh Chandra
Dept of Conservative and Endodontics CONTENTS : CONTENTS HISTORY
CLASSIFICATION OF ENDODONTIC INSTRUMENTS
CLEANING AND SHAPING INSTRUMENTS
STANDARDISATION OF ENDODONTIC INSTRUMENT
ISO GROUP INSTRUMENTS
NEW CONCEPT IN INSTRUMENT DESIGN
CONCLUSION HISTORY: : HISTORY: 2200 years old Nabatean warrior skull oldest root canal filling
1750 – Fauchard recommended removal of pulp
1850 _ wooden pegs for debriding pulp
Early 1900 – Introduction of files, reamers, pathfinder, lentulospiral
1915 - Kerr manufacturing company obtained patent for all instruments later known as k_type instruments
1957 - Richman introduced first ultrasonic system
1958 – Ingle & Levine 1st proposed standardization.
1959 – New line of standardized instruments & filling materials. Slide 4: 1962 – Working committee on standardization .
1964 _ Introduction of giromatic handpiece.
1975 _ 1st report on potential application of NiTi alloys
1976 – 1st approved specification for root canal instruments.
1976 to 1984_ Martin and Cunningham provided instruments that were set for vibration at 25 to 40KHz
1984 - introduction of canalfinder system
1988 -1st use of NiTi in endodontic instruments
1989 – ANSI approval of “ADA specification number 28 for endodontic files & reamers.” CLASSIFICATION OF ENDODONTIC INSRUMENTS : CLASSIFICATION OF ENDODONTIC INSRUMENTS BASED ON FUNCTION
A)EXPLORING _to locate canal orifice and to assist in obtaining patency of root canal
B) DEBRIDING _to extirpate pulp and remove debris
C) CLEANING AND SHAPING _ clean and shape root canals laterally and apically
D) OBTURATING _To pack filling material into root canal
MODE OF USE
B) ROTARY Slide 6: ISO GROUPING
A) GROUP I - hand use only
B) GROUP II - engine driven latch type
C) GROUP III - engine driven latch type drills or reamers
D) GROUP IV - root canal points EXAMINING INSTRUMENTS : EXAMINING INSTRUMENTS Instruments used in examination are
1)front surface mouth mirror _ overcomes the problem of associated with double image
4)cotton forceps EXPLORING INSTRUMENTSENDODONTIC EXPLORERS: : EXPLORING INSTRUMENTSENDODONTIC EXPLORERS: Long, narrow working ends --- DG-16 & D-5
Angle away from shank – easy access.
Locate canal openings.
Explore pulp chambers. DEBRIDING INSTRUMENTSENDODONTIC EXCAVATOR : DEBRIDING INSTRUMENTSENDODONTIC EXCAVATOR Longer offset – better reach
Excise pulp tissue from pulp chamber BARBED BROACH, RASP AND APPLICATORS: : BARBED BROACH, RASP AND APPLICATORS: (ANSI sp. No :63)
The length of working portion of shaft is 10mm.
Taper – 0.007mm/mm (Broach).
Difference between broach and rasp _ depth and angle of cut.
Barb height – half of core diameter (Broach).
Barb height – one third of core diameter (rasp). Made from soft iron wire. Slide 12: Barbed broach – Thin, flexible, tapered and pointed
removal of intact pulp tissue, paper points and cotton dressings.
Identification symbol – 8 pointed star
Rasps – rough walled canal preparation.
Previously rattail file ISO GROUP I INSTRUMENTS : ISO GROUP I INSTRUMENTS MANUFACTURE:
First made from carbon steel
Now made universally of Ni-Ti and stainless steels.
Produced by two techniques.
1st technique Grinding graduated sizes of round “piano” wire into various shapes and second grinding for taper. Then, twisted in counter clockwise direction for programmed number of times.
2nd technique Grind spirals into tapered wire rather than twisting. Ni-Ti instruments are produced by this technique. Slide 14: 1955 – first attempt to standardize instruments by Ingle & Levine
Last revised in 2002
Numbers from 6 to 140 - based on the diameter of the instruments in hundredths of a millimetre at the beginning of the tip of the blades (D1)
Extends up the blade to the most coronal part of the cutting edge at D2 - 16 mm in length Instrument Standardization Slide 15: The full extent of the shaft, up to the handle,
comes in three lengths:
Short - 21 mm
Standard - 25 mm
Long - 31 mm Slide 16: The instruments enlarge by 0.02 mm/mm from D0 to D16
The tip angle of an instrument should be 75 ±15°
Color coding of instruments _ easier identification of instruments Slide 17: Instruments have a taper of 0.02 mm per mm
Presently, instruments with a taper greater than the ISO 0.02 mm/mm have become popular:
0.08 Parts of a file : Parts of a file K Files & Reamers : K Files & Reamers Designed in 1904 by Kerr Manufacturing Co.
Are the most widely copied and extensively manufactured endodontic instruments worldwide
Previously made of Carbon Steel
Presently made of Stainless Steel Slide 22: K File and Reamer are the oldest instruments used to machine dentin
These instruments work by the Compression – and – Release destruction of dentin surrounding a canal
Reaming motion causes less transportation of the apical dentin than a Filing motion Slide 24: Produced by grinding graduated sizes of round Piano wire into either a square or triangular configuration
Second grinding operation properly tapers these instruments
To give the instruments the spirals that provide the cutting edges, the square or triangular stock are then grasped by a machine that twists it counter clockwise a programmed number of times - tight spirals for files, loose spirals for reamers Slide 25: The cutting blades that are produced are the sharp edges of either the square or the triangle
In any instrument, these edges are known as the “Rake” of the blade
The more acute the angle of the rake, the sharper the blade
There are approximately twice the number of spirals on a file than on a reamer of a corresponding size Slide 26: New 30 K file with consistently
sharp blades and point 35 K file exhibiting dull blades Slide 27: Cross-sectional profile of
triangular No. 20 file showing consistency in angles Cross-section of competing No. 20
File with dull, rounded angles
of cutting blades Slide 28: The clinician should understand the importance of differentiating endodontic files and reamers from drills
Drills are used for boring holes in solid materials such as gold and enamel
Files, by definition, are used by a Rasping motion Reamers : Reamers Reamers, are instruments that ream - specifically, a sharp-edged tool for enlarging or tapering holes
They cut by being tightly inserted into the canal, twisted clockwise ¼ to ½ turns to engage their blades into dentin & then withdrawn
Penetration → Rotation → Retraction
Cut is made during Retraction Slide 30: Reaming is the only method that produces a round tapered preparation (In straight canals)
In a curved canal, the reamer should be rotated only ¼ turn, as more stress can cause breakage
Heavier reamers (Size 50 and above), can be turned without breakage
Newer Ni Ti reamers are flexible and resist breakage in smaller sizes K Flex Files : K Flex Files The Kerr Manufacturing Company in 1982 introduced a new instrument design that they termed the K-Flex File (Sybron Endo/Kerr; Orange California)
The cross-section of the K-Flex is Rhomboidal or Diamond shaped
The spirals or flutes are produced by the same twisting procedure used to produce the cutting edge of the standard K-type files Slide 32: This new cross-section presents significant changes in instrument flexibility and cutting characteristics
The cutting edges of the high flutes are formed by the two acute angles of the rhombus and present increased sharpness and cutting efficiency
The alternating low flutes formed by the obtuse angles of the rhombus are meant to act as an auger, providing more area for increased debris removal CLEANING AND SHAPINGINSTRUMENTSK FILES : CLEANING AND SHAPINGINSTRUMENTSK FILES Instruments with tighter spirals.
1.97 to 0.88 cutting flutes per mm of operating head.
Produced mainly from square blank.
Cutting action – either filing (rasping) or reaming (drilling) motion.
Filing – rake of flutes rasp the walls as the instrument is withdrawn without turning.
Reaming – penetration, rotation and retraction Slide 34: More work hardened – stiffer than reamers.
Identification symbol – square K REAMERS : K REAMERS Instruments with lesser number of flutes.
0.80 to 0.28 cutting flutes per mm of operating head.
Produced mainly from triangular blanks.
Cutting action penetration, rotation and retraction.
Identification symbol – equilateral triangle K-STYLE MODIFICATION : K-STYLE MODIFICATION K-FLEX:
Forerunner of hybrid instruments.
Hybrid – strength and versatility of K-type + aggressive cutting of H-type.
Cross-section – rhombus or diamond.
Cutting edge – Two acute angles.
Alternating low flutes – obtuse angle – increase debri removal.
Space reservoir – reduced compacting dentinal filing.
Increase flexible. HEDSTROEM FILES : HEDSTROEM FILES Cutting spiraling flutes into shaft of round, tapered stainless steel wire.
Very positive rake of flute design.
Impossible to ream or drill.
Cut in one direction – retraction.
Cross-section – single helix teardrop FLEXOFILES: : FLEXOFILES: Flexible file_ triangular cross section stainless steel blank
Non cutting tip(1.81 flutes per mm)
Golden medium _similar in design INTERMEDIATE FILES : INTERMEDIATE FILES Produced trimming 1mm from tip of file and rounding off sharp edges on a diamond file
Files changed from
10 to 12
15 to 17
20 to 22
25 to 27
Advantage -smooth progress through files
Disadvantage - disposable , edges difficult to smooth may cause ledging OBTURATING INSTRUMENTSENDODONTIC CONDENSERS AND SPREADERS: : OBTURATING INSTRUMENTSENDODONTIC CONDENSERS AND SPREADERS: Smooth tapered metal instruments – compress and compact gutta-percha
Pluggers or condensers – blunt or flat-ended tips Spreaders – more tapered and pointed tips Long handled – chrome plated or stainless steel Slide 42: M series plugger-spreaders – double-ended long-handled instruments
Handles colour coded
Corresponds to standard sizing and taper of K-type files
Finger held spreaders and condensers – similar to K-type files with plastic or metal handles. ENDODONTIC PLIERS AND FORCEPS: : ENDODONTIC PLIERS AND FORCEPS: Handling and placement of silver point and gutta-percha cones.
Pliers – tapered groove in beak for grasping silver cone.
Forceps – grooved or serrated beaks for holding gp cones.
Have latch mechanism for locking in closed position. NiTi spreaders : NiTi spreaders NiTi finger spreaders
Used in curved canals for good obturation ISO GROUPS II AND III : ISO GROUPS II AND III Engine – driven instrument use – 3 types of contra angle handpiece.
A full rotary handpiece – Latch or friction grip.
Special handpiece – vertical stroke with reciprocating quarterturn. ISO GROUP II – Instruments with shaft and operating head as separate pieces ISO GROUP III –
Instruments with shaft and operating head as one piece. ROTARY CONTRA ANGLE HANDPIECE : ROTARY CONTRA ANGLE HANDPIECE Instrumentation – Straight line drilling or side cutting.
With round or tapered burs – coronal access to canal orifice.
With special reamers – Funnel out orifices.
With Nickel titanium reamer type instruments – Clean and shape canals,
Misdirected or forced behind limits – Perforations. Slide 47: Solution – Use of slower handpiece.
Ex: 1) Medidenta/ Micro Mega MM 324 reduction gear Handpiece.
2) Aseptico Electric Motor handpiece.
3) The Quantec ETM.
4) The Moycol union broach sprint EDM.
Speeds – 300 rpm for NiTi profiles.
2000 rpm for Light Speed instruments.
Newer electric handpieces – Both speed and torque control.
New rotary handpiece – Morita Tri Auto ZX.
Tri Auto ZX – Battery – powered slow-speed (280 rpm) handpiece with a built in apex locator.
NiTiMatic _ 16:1 gear reduction handpiece
300 rpm RECIPROCATING HANDPIECE: : RECIPROCATING HANDPIECE: Giromatic handpiece – Accepts latch type instruments.
Canal insruments available for use with GIROMATIC
giro pointer _ 16mm long orifice opener
giro broach or cleanser
giro file,a hedstroem configuration
heli girofile_3 cutting blades in c.s
Quarter-turn motion – 3,000 times per minute. Slide 49: M4 safety handpiece – 30 degree reciprocating motion.
Regular hand files by their handles.
Endo-Gripper – 10:1 gear ratio, 45 degree turning motion.
Endo Cursor _ press button chuck
Take hand instruments RANDOM HANDPIECE : RANDOM HANDPIECE Excalibur _ lateral vibrational movement
20000 to 25000 r.p.m.
Use modified K files ISO GROUP II : ISO GROUP II Instruments with shaft and operating head as separate pieces:
B-2 reamer – cylindrical working head
2 cutting edges – spiral
c.s – rectrangle
working head and shaft – similar to
Used with contraangle or straight handpiece
Lentulospiral – power-operated, spiral.
Used with contraangle or straight handpiece Slide 52: Quarter-turn reamer – power-operated,
tapered and pointed
used with giromatic or racer handpiece
enlarge/widen root canal
similar to blank of K-type. McSpadden compactor – specially designed
Apically directed spirals.
frictional heat softens guttapercha
Other group II – K-reamer, H file, R-type rasp, barbed broach
Used with giromatic or racer handpiece ISO GROUP III : ISO GROUP III Shaft and operating head as 1 piece.
G-type reamer – GG drill
stainless steel or NiTi
Short, flame-shaped head with side cutting blades
Short, non-cutting guide at tip
Long-thin neck connects working head and shaft.
Number 1 to 6
Used with gear reduction, slow speed, high torque handpiece
Speed – 750 to 1000 RPM
B-1 reamer – similar to G-type.
Twice long working head. Slide 54: O-type reamer – long, tapered head
3 spiralling blades – plane angle
P-type reamer – Paeso drill
Long, narrow, tapering head
Side cutting, spiral blades
Tip – cutting /non-cutting.
Number 1 to 6 BURS: : BURS: Burs with extended shank –
preparation in pulp space with low
Surgical length – 26mm.
Extra long shank – 34mm
Ex: Brasseler, shank 25
Good visibility and control
Friction grip tapered fissure burs (557 or 701) – correct outline form.
Round burs – normal and extra long
Size 2, 4, 6
Longer and smaller round burs – fine calcified canals.
Safe ended diamond / tungsten carbide bur / endo2 bur – taper, smooth access cavity. ULTRASONIC INSTRUMENTS: : ULTRASONIC INSTRUMENTS: System in which sound as an energy source activates an endodontic file resulting in a three dimensional activation of the file.
File – Vibrates in a sinus wave like fashion.
Antinodes _ maximal displacement (tip).
Nodes – no displacement.
Fracture – at the nodes.
Debriding action – Cavitation and acoustic streaming.
Cavitation – positive pressure followed by a negative pressure in the fluid.
Cavity formed in the negative phase implodes with great force during next positive pressure phase.
Acoustic streaming – small, intense, circular, fluid movement.
occurs closer to the tip. Slide 57: Various ultrasonics used
Cavitron endodontic system.
Piezon master 400.
20 to 25 KHZ – used.
Piezoelectrical design – Decreased heat
Magnetostrictive – Increased heat decreased energy.
Endosonic ultrasonic synergistic system – instrumentation + irrigation. Slide 58: Cavi-Endo ultrasonic unit – 1st
Use either inert sterile or chemically active irrigant.
Modifications of K-type or R-type.
Endosonic diamond file – cutting of dentin by abrasion.
Ultrasonic tips – used in detection of canal orifices.
removal of posts, fractured instruments, coating canals with sealer SONIC INSTRUMENTS: : SONIC INSTRUMENTS: Sonic systems – vibration in audible frequency range
Frequency – 2 to 3 KHZ.
Micro Mega 1500 sonic Air endo system – Airline pressure of 0.4 MPA.
Sonic file – large elliptical motion at the tip.
Loaded – longitudinal motion, up and down.
Oscillatory range – 1500-3000 cycles per second.
Three sonic files used – Rispisonic, shaper sonic, Trio sonic. Slide 60: Rispisonic – old rat tail file (8 cutting blades)
Shaper sonic – husky barbed broach. (16 cutting blades).
apical one third
Triosonic – tripled helix H file.
Sizes – 15 to 40.
Length – 17 to 29mm.
Rougher canal surface.
Endosonic 3000- sonic handpiece similar to sonic air driven scalers.
Irrigation – filtered water.
Dis advantange –perforations, transportation. ISO GROUP IV: : ISO GROUP IV: Not strictly endodontic instrument but have been considered part of armamentarium under developing international standards.
Slender cones made of paper or other absorbent material.
Uses – drying the canal
Obtaining canal cultures
Available in standardized sizes ROOT CANAL FILLING POINTS : ROOT CANAL FILLING POINTS Smaller, slender cones of solid material.
Used for canal obturation.
Ex: silver points, gutta-percha points.
Available in standardized sizes and taper NON-ISO INSTRUMENTS : NON-ISO INSTRUMENTS Advent of NiTi _ newer instrument system
Instruments with greater taper
Tapers _ 4% ,6% ,8% ,10% ,12%
RADIAL LAND – “The surface that projects axially from the central axis between the flutes”
PITCH – “Number of flutes per unit length” Slide 64: ProTaper “For Hand Use” features exactly the same instruments and clinical sequence as the rotary version
It is for the all hand file users wishing to benefit from NiTi and crown-down technique. Slide 65: SHAPING FILE SX Length: 19 mm SHAPING FILE S1 SHAPING FILE S2 Length: 21, 25
and 31 mm FINISHING FILE F1 FINISHING FILE F2 FINISHING FILE F3 Motion of File : Motion of File Lightly engage dentin by gently rotating the file clockwise until the file is snug
Disengage the file by rotating handle counter clockwise 45-90 degrees
Cut dentin by rotating the handle clockwise while withdrawing the file
Repeat until length is reached PROTAPER: : PROTAPER: Multiple tapering – fewer files required to create a tapered shape.
Used – curved canals, restricted canals
Both rotary and hand instruments
Increased efficiency, effectiveness.
Length – 19, 21, 25mm.
Protaper SX, S1, S2, F1, F2, F3,
Developed by Drs.Clifford Ruddle, John West, Pierre Mactar and Ben Johnson
Designed by Francois Aeby and Gilbert Rota Slide 68: Shaping files
SX shaper – canals of teeth with shorter roots
expand the coronal aspect of preparation
increased rate of taper
Do – 0.19mm, D9 – 1.1mm,D14_ 1.2mm
rate of taper drops from D9 to D14
S1 shaper – D0 – 0.17mm,D14 _ 1.2mm
prepare coronal third of canals
S2 shaper – D0 – 0.20mm ,D14 _ 1.1mm
prepare middle third along with coronal region of apical third Slide 69: Finishing files
To plane away variation in canal diameter in apical one third
F1 – size 20, taper 0.07mm/mm (D0 to D3)
F2 – size 25, taper 0.08mm/mm (D0 to D3)
F3 – size 30, taper 0.09mm/mm (D0 to D3)
Speed – 200 to 300 RPM
Used in torque and speed control electric motor handpiece