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Cleanliness is next to Godliness....

Cleanliness is next to Godliness. ENDODONTIC INSTRUMENTS. MATERIALS STANDARDIZATION CLASSIFICATION FILE DESIGN HAND INSTRUMENTS HANDPIECES INSTRUMENTS CONCLUSION. CONTENTS. MATERIALS USED. MATERIALS. Carbon steel Stainless steel Titanium Nickel titanium. Materials used:

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Cleanliness is next to Godliness....

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  1. Cleanliness is next to Godliness.... ENDODONTIC INSTRUMENTS

  2. ENDODONTIC INSTRUMENTS ENDODONTIC INSTRUMENTS

  3. MATERIALS STANDARDIZATION CLASSIFICATION FILE DESIGN HAND INSTRUMENTS HANDPIECES INSTRUMENTS CONCLUSION CONTENTS ENDODONTIC INSTRUMENTS

  4. MATERIALS USED ENDODONTIC INSTRUMENTS

  5. MATERIALS • Carbon steel • Stainless steel • Titanium • Nickel titanium ENDODONTIC INSTRUMENTS

  6. Materials used: a) In 19th century carbon steel was used for manufacturing of instruments. Disadvantages fracture tendency due to the brittleness of metal. corrosion along with NaOCl irrigant and during steam sterilisation. b) In 20th century stainless steel was used by Kerr manufacturing company . Advantages : It is flexible ,hence less likely to fracture when strained. less susceptible to corrosion. Disadvantage: when canal curvature is > 450 it may fracture

  7. c) Nickel titanium (nitinol) NiTi__most flexible Advantages – low elastic modulus and thus provides very good elastic flexibility to instrument ,hence used in curved canal shape memory alloy ---it has the ability to recover from plastic strain when unloaded. Dis advantage –expensive difficult to manufacture and mill. d) Titanium and aluminium alloy.

  8. Standardisation ENDODONTIC INSTRUMENTS

  9. STANDARDISATION: Ingle and Levine in 1958 recommended. describes 3 features a) Diameter and width b) Length of cutting blade c) Taper ENDODONTIC INSTRUMENTS

  10. D1---1/100th of mm D2---D1+0.32mm Taper is 0.02mm/mm of length STANDARDIZATION • Ingle and Levine (1959) • Instruments No. 10-100 • Diameters- 1/100 of tip • D1 and D2 ENDODONTIC INSTRUMENTS

  11. 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 D2is in increments of 0.02mm in width/mm of length ENDODONTIC INSTRUMENTS

  12. So, the diameter of D2 shall be 0.32mm greater than D1 ex: 20 reamer-------D1 is 0.2 D2 is 0.2+0.32= 0.52 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. ENDODONTIC INSTRUMENTS

  13. Instruments are available in different lengths • 21mm, 25mm,28mm, 30mm,40mm • 21mm length is used for molars • 25mm length is used for anteriors • 28 & 30mm length is used for cuspids • 40mm reamers used in preparing canals for endodontic • implants ENDODONTIC INSTRUMENTS

  14. 4) Instruments are color coded ENDODONTIC INSTRUMENTS

  15. For narrow Root canals- size 06, 08 , 10 are used pink grey purple Modifications –of k-flex files Length of flutes is 18mm from tip to extent I.e D1and D2 not signified This recommends use of D0 and D16 D0-------------- D16 1mm above D0 is D1 D17 - D18 are also present ENDODONTIC INSTRUMENTS

  16. In Jan 1976, ASI [American std institute] granted approval of ADA Specification. No.28 for endo files and reamer No.58 for H files ENDODONTIC INSTRUMENTS

  17. ADA Specification. No.28 revision in March 1981 stated • instrument sizes No.6,8,10,15 were added to original • standardisation • 2) D1 and D2 changed to D0 and D16 • Six factors considered while analyzing endo instrument • Material that is cut • Anatomic configuration of r.c • Material of cutting instrument • Manufacturing process (grinding / twisting) • Design of instrument (files – reamer) • Fluid used during procedure. ENDODONTIC INSTRUMENTS

  18. Manufacture of instrument ENDODONTIC INSTRUMENTS

  19. Manufacture of instrument: In early 1900’s Kerr manufacturing company designed and manufactured new K type endodontic instrument. Initially the instrument were manufactured from round tapered piano wire (carbon steel), but now they are made from st. steel blanks. ENDODONTIC INSTRUMENTS

  20. The st.steel wire is ground along its long axis into a 4 Sided (square c.s) or 3sided (triangular c.s) tapered shaft that is twisted into flutes extending 16mm from the top to the tip of blade . The number of flutes twisted into each blade determines whether instrument is a file or reamer. Files---tighter flutes Reamers---looser flutes ENDODONTIC INSTRUMENTS

  21. Recently rhomboidal or diamond shaped blanks are twisted to produce a file---K flex to increase flexibility & cutting efficiency. H files– Manufactured from round st.steel wire machined to produce spiral flutes resembling cones or screw. Unifiles Machined from round st.steel wire by cutting 2 superficial grooves to produce flutes in a double helix design. ENDODONTIC INSTRUMENTS

  22. The cutting edges may be generated by twisting the metal shaft along its long axis or by machining it. When twisted, square blank produces rigid instrument, the triangular shape is flexible, rhomboid shape is more flexible. When machined, the depth of cut used to produce the flutes dictates the flexibility and strength of the instrument.They tend to be more susceptible to fracture. ENDODONTIC INSTRUMENTS

  23. CLASSIFICATION ENDODONTIC INSTRUMENTS

  24. CLASSIFICATION • According to Grossman • Exploring instruments • Instruments for debridement • Shaping instruments • Obturating instruments ENDODONTIC INSTRUMENTS

  25. 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 & smooth broaches 2) Debridement : to extirpate the pulp to remove cotton pellets or paper points Egs : barbed broach 3) Cleaning & Shaping Egs : Reamers and file ENDODONTIC INSTRUMENTS

  26. 4) Obturating : For condensation of G.P & to create space laterally Egs : Spreaders and pluggers lentulospirals [engine driven,latch type of attachment and Working portion is spring like that is coated with RC sealer. ENDODONTIC INSTRUMENTS

  27. 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 ENDODONTIC INSTRUMENTS

  28. 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. ENDODONTIC INSTRUMENTS

  29. According to Stock: Twisted Machined ENDODONTIC INSTRUMENTS

  30. Broaches and Rasps: oldest endo instrument • : used for removal of pulp tissue • : used for removal of cotton or paper points from R.c • Broach Rasp • Barb height is large It is small • As the barb comes out of • instrument,broach is a weaker • instrument compared to rasp • 3. Taper is 0.007 to 0.01 mm/mm Taper is 0.015 mm/mm ENDODONTIC INSTRUMENTS

  31. More fragile because of depth of shallower and • cut rounded barbs • 5. Coronally angulated barbs perpendicular to long axis of metal • Both are not used beyond middle 3rd of R.c and also entangle in R.c and get separated ENDODONTIC INSTRUMENTS

  32. Differences in files and reamers • Fracture • More in counterclockwise 90° 60° ENDODONTIC INSTRUMENTS

  33. K- File • Produced by twisting a 4 sided • pyramidal blank I.e Square c.s • The instrument have between one • quarter to ½ spiral per mm length • The file has more flutes per length • unit than the reamer • The blade angle makes them • best suited for cutting dentine using • a push pull filing motion. • [K type instrument works by crushing the dentin when turned into a canal smaller than the diameter of the instrument] ENDODONTIC INSTRUMENTS

  34. K Reamer: ENDODONTIC INSTRUMENTS

  35. K Reamer: The instrument is produced by twisting a 3 sided blank i.e triangular c.s which makes reamer more flexible than files. These instruments have less than one tenth and one quarter of a spiral per mm of length giving a rake angle which cuts more efficiently using a rotary motion ,hence reaming motion. They are used with a rotating pushing motion limited to half turn and disengage with a pulling motion ENDODONTIC INSTRUMENTS

  36. Flutes are placed farther apart and hence more space between flutes allowing better transport of dentin debris Angle less than 90 ,cutting efficiency is more. If surface area is less , then flexibility is more. ENDODONTIC INSTRUMENTS

  37. Reaming— place instrument till apical constriction and give ¼ to ½ turn and pull out. In narrow canal-less turn is given and in wider canal large turn is given. Files can be used in reaming motion,but reamer does not cut efficiently in filing motion. ENDODONTIC INSTRUMENTS

  38. 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 ENDODONTIC INSTRUMENTS

  39. K style modification----K flex file It was introduced in 1982 This instrument is twisted from a tapered blank with a rhombic c.s that produces alternating high and low flutes that increase flexibility and cutting efficiency of instrument and also facilitates removal of debris. a<90 improved cutting efficiency b>90 (obtuse angle) does not contact R.C,increased debris removal Used in curved and narrow canals. a b b a ENDODONTIC INSTRUMENTS

  40. Flex O files • It is very similar to K file but is made from softer more flexible steel • It does not fracture easily and is very flexible. • Tip is modified to non cutting ENDODONTIC INSTRUMENTS

  41. Golden medium: Range of intermediate files described by Weine provide half sizes between traditional instruments for narrow canals (instrument should be intermediate to 12-20 Sizes from 12-32 (12,17,22,27,32,37) manufactured by maillefer. ENDODONTIC INSTRUMENTS

  42. (weine suggested trimming 1 mm from the tip of the file rounding off sharp edges on diamond nail file) In this way, file sizes 10,15 20 25 may be converted to 12,17,22,27. Disadvantage is files are made disposable ,and edges are difficult to smooth. ENDODONTIC INSTRUMENTS

  43. Flex R file: designed to be used in balanced force technique. Machined from blank of triangular c.s Non cutting tip ENDODONTIC INSTRUMENTS

  44. An instrument is rotated a quarter turn [clockwise] as gentle pressure is exerted to insert it. • This action positions the cutting edges equally into the walls. • Next it is rotated anticlockwise at least 1/3 of a revolution. • Simultaneous apical pressure and anticlockwise rotation of file sustains a balance between tooth structure and instrument so that it is near the canal axis. ENDODONTIC INSTRUMENTS

  45. Heliapical: This instrument resembles conventional file in the apical 4-5mm the remainder being a narrow blank shank Small sizes fracture ENDODONTIC INSTRUMENTS

  46. HEDSTROM FILES (ANSI 58) • Milled instrument- multiaxial grinding • Positive rake angle • Cuts in pull motion • Uses ENDODONTIC INSTRUMENTS

  47. H- File machined instrument It is machined from a blank of circular c.s. The flutes are produced by machining a single helix into the metal stock, producing a series of intersecting cones which increase in size from tip to handle . The strength and flexibility is determined by the depth of flute or residual bulk of metal in central portion of file. ENDODONTIC INSTRUMENTS

  48. The blades are at right angles to dentine surface and so most efficient cutting motion is a pulling stroke. No dentine is removed by push stroke Rotating the instrument with a tip of file engaged in dentin is a common cause of fracture. ENDODONTIC INSTRUMENTS

  49. They are aggressive cutters. It resembles ‘Christmas tree’ appearance. [cone over cone] used to remove loose broken instrument. Disadvantage: Fracture tendency because of depression between flutes causing narrowness between core material. ENDODONTIC INSTRUMENTS

  50. H- Style Modification: Burns uni file: It is identical to H file but it has two cutting blades instead of single cutting blade. S-shaped c.s or double helix design cuts more efficiently ENDODONTIC INSTRUMENTS

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