Endodontic instruments

Materials

Carbon steel

Stainless steel

Nickel titanium

Titanium

ISO standardization (Ingle and Levine)

1. Numbered from 10 to 100. Advance by 5 units to size 60, then by 10 units to size 100.

2. Representative of the diameter of the instrument in 100ths of a millimeter at the tip.

3. Flutes shall begin at the tip, (D1) and shall extend exactly 16 mm up the shaft, terminating at D2. The diameter of D2 shall be 32/100 or 0.32 mm greater than that of D1.

MODIFICATIONS:

D3

D16

Classification

Grossman

Exploring instruments

Instruments for debridement

Shaping instruments

Obturating instruments

ISO Grouping

Group I: hand use only

Group II: engine-driven latch type

Group III: engine-driven latch type

Group IV: root canal points

Cohen

Hand instruments: those specific to endodontics

Instruments for pulp space preparation

Devices for root canal length measurements

Instruments for root canal obturation Devices for removal of root canal

obstructions

ADA

Type I : Reamers Type II : Files Type III : Hedstroem files Type IV : Rasps Type V : Broaches Type VI : Probes Type VII : Applicators Type VIII : Condensers Type IX : Spreaders

Harty

For access cavity preparation Basic instruments Burs Rubber dam

For root canal preparation Hand instruments Power assisted root canal

instruments

Electronic canal measuring system

Measuring instruments, gauge and stands.

Instruments for retrieval of broken instruments and pastes.

Instruments for root canal filling

Hand instruments specific to endodontics

DG 16 EXPLORER

ENDODONTIC SPOON

LOCKING PLIERS

Burs for access cavity

File Design

Rake Angle

Negative rake angle

Positive rake angle

Cont..

Negative angle Positive angle

… in rotary instruments

Core

The core is the cylindrical center part of the file having its circumference outlined and bordered by the depth of the flutes.

Core taper

Flute depth also influences core diameter in the same series of files.

Tip design

Active Partially active Passive

Taper

ISO 02

ISO 06

Torque

Torque – force producing rotation.

Instrument mass

Surface area of contact

Radius of curvature

Instrument Failure

Torsional failure Flexural fatigue

When torque limit of the instrument is exceeded

Arises from minute surface defects and occurs after cyclic fatigue

ISO Group I

1904

Broaches

Barbed broaches Rasps Smooth

broaches – Pathfinder CS

K reamer vs. file

K file modifications

K-Flex

Flex-R

Cont..

Flexofile

Flexicut

Golden Mediums

H-files: ADA Specification No. 58

H-file Modifications

Burns Unifile Dynatrak S-file Safety Hedstroem NT Sensor file (MAC file) A-file

Unifile

Non-cutting tip

A-File

H-File A-File

Safety Hedstroem

Safe sided

Apical Preparation Hand Instruments

Apical Reamers (Otani) Canal Master (Wildey and Senia) Canal Master – U Flexogates Heliapical

Canal Master and Canal Master U

Wildey and Senia 1-2mm cutting head 0.75 mm non-cutting head Blank shaft

Flexogates

Hand modification of GG drills

Heliapical

Apical 4-5mm length Blank shaft

U-files – Heath (1988)

Canal Master U Ultra-Flex NITIMAC Lightspeed,

ProFiles, GT files

Instruments for obturation

Spreaders Pluggers

Hand pluggers

Lentulospirals

Sotokawa’s Classification of Instrument Damage

ISO Group II and III

1912

Handpieces

Classification – Ingle

Full rotary– latch/friction grip

Reciprocating/Quarter turn

Special – vertical and reciprocating

Sonic and Ultrasonic

Stock

Rotary

Reciprocal

Vertical

Random

Advantages Easy to use

Saves time

Reduction in fatigue

Reduction in treatment time

Disadvantages Transportation, ledging

and perforations

Hand instrumentation necessary

Apical packing of debris

Rotary Contra-angle Handpieces

Straight line drilling Uses

To develop coronal access

Prepare post space channels

Widen the coronal two thirds of canal

With ss instruments used in straight canals only

Reciprocating Handpieces

Giromatic – quarter turn (90º) Latch-type only 3000 turns/min

Cont…

M4 Safety Handpiece (30º) Latch and regular hand

files 1500 rpm

Endo-Gripper (45º) Regular hand files 10:1 reduction

Vertical Stroke Handpiece

Canal Finder – Levy 0.3-1 mm stroke Used with A-file Additional

quarter turn reciprocal motion

Cont…

Canal Leader 0.4-0.8mm 30º

Racer Intra-Endo 3-

LDSY Endolift

Random Movement

Excalibur Random lateral motion only 1.5-2mm lateral motion 20,000-30,000 rpm

Engine driven instruments

Gates Glidden drills – safe tip Orifice opening Deeper penetration into straight canals Removal of lingual shoulder

Peeso reamers Post space preparation Use safe-tipped to prevent lateral

perforation

Availability – Nos. 1 to 6

Martin’s Orifice Opener

More flexible

25-70

McSpadden Engine files NiTi instruments:

Sensor files – redesigned H NiTiXL Finishing file – U – style NT Power file

Gear Reduction Handpieces

Spin burs at speeds lower than the motor speed

Ratios ranging from 8:1(1/8th motor speed) to 27:1 (1/27th motor speed)

Green Band

Quantec ETM MicroMega 324 Aseptico New:

TriAuto ZX TCM ENDO Endo-Pro Electric Protorq

Sonic Handpieces – 2-3 kHz

SONIC AIR OSCILLATIONS

Sonic instruments

RispiSonic

ShaperSonic

TrioSonic

Ultrasonic Handpieces – 20-30 kHz

MAGNETOSTRICTIVE

PIEZOELECTRIC

N = NODES

A = ANTINODES

Cavitation

Acoustic Microstreaming

Ultrasonic tips

NiTi Rotary Systems

Nickel-Titanium

1962 – Buehler Naval Ordnance Laboratory 55 NiTiNOL

55 wt % Ni 45 wt % Ti 2% Ni substituted with Co Equiatomic alloy

1988 – Walia et al - endodontics

Properties

Show shape memory and superelasticity

Softer than stainless steel Not heat treatable Have a low modulus of elasticity; but

greater strength Tougher and more resilient VHN is 300-350 (SS-530) Lower cutting efficiency

Deformation

Stress

AUSTENITE MARTENSITE

Superelasticity and Shape Memory

Manufacturing

ELECTROPOLISHING NORMAL FINISH

ProFile Family

Profile 04 and 06

Orifice Shapers GT files

strength and flexibility

radial-landed U-shaped flutes that lift debris coronally

noncutting tips

ProFile Series 29 - 1992

Machtou and Schilder

Constant percentage change

(B) D0 – (A) D0 Х 100

(A) D0

Percentage Change =

10-15 = (0.15-0.10)/ 0.10 Х 100 = 50%

15-20 = (0.20-0.15)/ 0.15 Х 100 = 33%

50-55 = (0.55-0.50)/ 0.50 Х 100 = 10%

Standardized instruments

% Increase in diameter at D0

Instrument sizes

15

10

percentage change = 29% 0.129-1.000 mm

ProFile 04 and 06 - 1994

Sizes 15-40

Orifice Shapers

10mm cutting blades

D0 20-60 Taper 05-08

Greater Taper files

1996, Stephen Buchanan

D0=0.20mm MFD=1.0 mm Variable pitch and

lengths Tapers:06, 08, 10,

12

GT Accessory files

3 instruments Taper=12 MFD=1.5 mm D0= 0.30, 0.50,

0.70 Coronal shaping

Protaper – Progressive Taper

Pierre Machtou, Clifford Ruddle and John West – 2001

Shaping files..

SX D0=0.19mm Taper=3.5-19%

S1 D0=0.17mm Taper=2-11%

S2 D0=0.20mm Taper=4-11.5%

Finishing files…

F1 D0=0.20mm D0-D3=7%

F2 D0=0.25mm D0-D3=8%

F3 D0=0.30 D0-D3=9%

Lightspeed Wildey and Senia – 1992 Sizes

20-140 5 half-sizes: 22.5,27.5, 32.5, 57.5, 65

Thin shafts- 0 taper 0.16-0.51 mm diameter

Speed 1500 rpm

Cont..

Cutting heads - variable Length= 0.25mm –

2.25mm Tip angles= 21, 33,

75 Non-cutting

Quantec

McSpadden Reduced radial lands 2 fluted

Types…

Safe Cutting SC (60º)

Non-Cutting LX

cont…

D0=0.25mm Taper= 02, 03,04, 05, 06, 08, 10,12% Variable helical angle 340 rpm

HERO 642

High Elasticity in Rotation

Tapers: 06, 04 and 02% Trihelical

Hedstroem design

Large central core

20 to 45

K3

McSpadden 2002 02 taper – 15-45 04, 06 taper –

15-60 Safe-ended

Positive rake angle

Vs.

Variable core diameter

Variable helical flute angle

Stronger cutting blade

Relief = less friction

Third radial land – no relief

Axxess handle = 4mm shorter

Newer Systems

Liberator

Straight-flute design cannot self-thread

Lack of radial lands reduces friction

High RPM – 1500-2000

Roane safety tip

Manufacturing eliminates transverse microcracks

02, 04, 06 tapers

15-70 sizes Coronal shapers

Modified GG Taper= 08 D0=118,94,70

RaCE

Reamer with alternating Cutting Edges

prevent the threading

an extremely low operating torque

Sharp cutting edges

Safety MemoDisc® for controlling NiTi fatigue;

Electro-chemical treatment: better resistance to torsion and metal fatigue

S-Apex

Apical preparation after using Race Inverted taper Non-threading Predetermined breaking point 15-30 sizes

Weakest part at 16mm

Endosequence

Brave and Koch

Triangular cross-section

No radial lands

Alternating Contact

Points (ACP) Electropolished

surface Precision tip

Files…

Taper – 04 and 06

4 files each Small

15-30 Medium

25-40 Large

35-50

Expeditor file O4 taper 27 size 21mm

Coronal channeling and gauging

M Two

Taper – 04-07 10-40 sizes 4 instruments

Almost straight flutes

2 flutes