Endodontic Instruments

Classification International Standards Organization (ISO) has grouped root canal instruments according to their use: Group I: hand use only: Files H-type K-type reamers and files Broaches Group II: engine driven latch type Same design as in group I but made to attach to hand piece. Profile, Lightspeed Group III: engine driven latch type Low speed instruments where latch type attachment is in one piece with working part. Gates Glidden drills and Peeso reamers. Group IV: root canal points. Gutta percha, silver points and paper points.

According to Grossman [based on the function] 1) Exploring : to locate the canal orifices. to determine or assist in obtaining patency of the R C Egs : Endodontic explorer 2) Debridement : to extirpate the pulp to remove cotton pellets or paper points Egs : barbed broach 3) Cleaning & Shaping Egs : Reamers and file 4) Obturating : For condensation of G.P & to create space laterally Egs : Spreaders ,pluggers and lentulospirals

Materials used: a) In 19th century carbon steel was used for manufacturing of instruments. Disadvantages brittleness of metal, corrosion during steam sterilisation. b) In 20th century stainless steel was used by Kerr company . Advantages : It is flexible , less fracture ,less susceptible to corrosion. Disadvantage: when canal curvature is > 450 it may fracture

c) Nickel titanium (nitinol) NiTi__most flexible Advantages – low elastic modulus, very good elastic flexibility- used in curved canal, shape memory alloy, corrosion resistant and biocompatibility Dis advantage –expensive , poor cutting, easily fracture, difficult to manufacture and mill. -it has the ability to recover from plastic strain when unloaded.

Hand instruments specific to endodontics ENDODONTIC SPOON DG 16 EXPLORER LOCKING PLIERS

Burs for access cavity

STANDARDISATION: Ingle and Levine in 1958 recommended. - 3 features a) Diameter and width b) Length of cutting blade c) Taper D1---1/100th of mm D2---D1+0.32mm Taper is 0.02mm/mm of length

Instrument are numbered from 10 to 100, the numbers to advance by 5 units to size 60 and then by 10 units till size 100 2) Each number shall describe the diameter of instrument in 100th of a mm at the tip ,eg: size 10-tip is 0.1mm 3) The working blade (flutes) shall begin at the tip designated as D1, and the flutes extends to the length of 16mm designated as D2 Taper of the instrument from D1 to D2 is in increments of 0.02mm in width/mm of length

So, the diameter of D2 shall be 0.32mm greater than D1 ex: 20 reamer-------D1 is 0.20mm D2 is 0.20+0.32= 0.52mm Other specifications: a) Tip angle of instrument----75° ± 15 ° b) Instrument sizes should increase by 0.05mm at D1 between 10 to 60 And by 0.1 mm from 60 to 100 for increased instrument selection.

White 15 45 90 Yellow 20 50 100 Red 25 55 110 Blue 30 60 120 Green 35 4) Instruments are color coded White 15 45 90 Yellow 20 50 100 Red 25 55 110 Blue 30 60 120 Green 35 70 130 black 40 80 140 For narrow Root canals- size 06, 08 , 10 are used pink ,grey purple

Broaches : oldest endo instrument : used for removal of pulp tissue : used for removal of cotton or paper points from Root canal Broach Barb height is large As the barb comes out of instrument, broach is a weaker instrument compared to rasp Taper is 0.007 to 0.01 mm/mm Barb are Fine and longer Broachs should not be used beyond middle 3rd of Root canal and also entangle in Root canal and get separated

Files Reamer Square c.s triangular c.s Tighter flutes loose spirals Resists fracture better. Cutting efficiency is 2.5 times more Maintains keen edge sharpness is lost rapidly More number of flutes less number of flutes Filing and reaming motion reaming motion

H- File machined instrument It resembles ‘Christmas tree’ appearance. [cone over cone] used to remove loose broken instrument Circular in cross section. Spiral grooves Cuts only when the instrument is pulled Cuts very aggressively Used in straight cannels Less flexibility Fractures when used in torque motion science theEdges faces the handle,

Group 3- Slow Speed Engine driven Stainless Steel 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

Armamentarum for obturation Spreaders Pluggers Lentulos spirals Scissors for cutting gutta purcha Endogauge for measuring gutta purcha points Tweezer for carrying gutta purcha points Spreaders Pluggers Endogauge Scissors Tweezer

Obturation instruments Spreaders- used for lateral condensation made up of stainless steel and having sharp ends (15 – 45 ) 2 types – hand - Finger Pluggers- used for vertical and condensation- blunt end 2 types – hand – vertical and lateral condensation - Finger - vertical condensation Lentulos spirals: used to carry sealer cements to root canal

Vertical and lateral condensation

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