1. Cleaning and Shaping of the Root Canal System. Part II
Edit by Hou Tiezhou

2. Root Canal Instrumentation
Estimate working length
Verify canal patency
Estimate canal size
Establish actual working length

3. Root Canal Instrumentation
Crown down preparation
Coronal third
Middle third
Apical third

4. Armamentarium

5. Armamentarium

6. Armamentarium Stainless steel size 10 K-files
Used to explore canal patency
Filing or quarter turn pull motion
Do not rotate through 360 degrees

7. Armamentarium Stainless steel size 15 and 20 K files
Used to establish actual working length

8. Armamentarium

9. Armamentarium Profile orifice shapers
Used to prepare the coronal one third of the root canal

10. Profile Orifice Shapers

11. Armamentarium Profile 0.06 taper rotary files
Used to prepare the middle third

12. Armamentarium

13. Armamentarium Profile 0.04 taper hand NiTi files
Used to prepare the apical third of the root canal

14. Armamentarium

15. Estimated Working Length
Estimated working length is the distance from the reference point to the radiographic apex, as measured on a parallel preoperative radiograph

16. Estimated working length
Take a pre-operative parallel radiograph
Clinically, use a XCP film holder

17. Estimated working length
Length from incisal edge to radiographic apex
Only an estimate because of radiograph distortion

18. Estimate canal size Radiographic appearance Crown/root morphology
Standardized sizes (See table in manual)

19. Estimate canal size

20. Explore Canal Patency
Ensure that canal can be negotiated to radiographic apex
Select #10 K file
Precurve file if necessary

21. Explore Canal Patency

22. Explore Canal Patency

23. Establish Actual Working length
Instrumentation should terminate at:
The apical constriction
1 mm short of radiographic apex
Actual WL = Estimated WL – 1 mm

24. Establish actual working length
WL can be established using:
Radiographs
Apex locator

25. Establish Actual Working Length

26. Establish Actual Working Length

27. Establish Actual Working Length

28. Establish Actual Working Length

29. Crown Down Preparation

30. Crown Down Preparation

31. Crown-down preparation
Plastic incisor with transparent root

32. Crown-down preparation
Place SS K file into canal until the tip is just visible at the apex

33. Actual Working Length Remove file from canal Subtract 1 mm
This is the actual working length
In this case the WL is 20 mm

34. Actual Working Length

35. Preparation of Coronal Third

36. Preparation of Coronal Third
The coronal third measurement is WL minus 8 mm, that is 12 mm
Profile OS do not have rubber stops – however the cutting flutes measure 10 mm
The goal is to work the largest OS to 12 mm

37. Preparation of coronal third

38. Preparation of coronal third

39. Preparation of the coronal third
Rotate OS at 300 rpm
Note: Orifice shaper should be rotating at 300 rpm before it is placed in the canal
Advance the OS in 1 mm increments
When resistance is encountered retract OS while still rotating
Never force any instrument apically

40. Preparation of coronal third
Blue (#60) OS extends to approx. 9 mm

41. Preparation of coronal third
Irrigation! Irrigation! Irrigation!

42. Preparation of coronal third

43. Preparation of coronal third
Gold (#50) OS reaches 12 mm

44. Preparation of coronal third
Progress from larger to smaller orifice shaper
Each smaller OS will extend further into canal
Repeat the sequence until the largest OS extends to 12 mm

45. Preparation of coronal third
Blue (#60) OS extend to WL – 8 mm = 12 mm

46. Preparation of Middle Third
Profile 0.06 taper series 29 rotary files

47. Preparation of Middle Third
Profile 0.06 taper series 29 rotary files
The middle third measurement is WL minus 4 mm, that is 16 mm
The aim is to work the brown (#7) file to 16 mm

48. Preparation of Middle Third
Proceed from larger to smaller file
Each smaller file will extend further into the canal
Repeat the sequence until the largest file extends to 16 mm

49. Preparation of middle third

50. Preparation of middle third

51. Preparation of middle third

52. Preparation of middle third

53. Preparation of middle third

54. Preparation of middle third

55. Preparation of middle third

56. Preparation of middle third

57. Preparation of middle third

58. Preparation of middle third

59. Preparation of apical third
Profile 0.04 taper nickel titanium hand files

60. Preparation of apical third
Profile 0.04 taper nickel titanium hand files
The measurement is the full working length, that is 20 mm

61. Preparation of apical third
Measure working length on #15 file
Set rubber stop at that length
Lubricate the canal with Prolube

62. Preparation of apical third
Advance size 15 file to working length
Rotate file through 360 degrees
Irrigate copiously with NaOCl after each file

63. Preparation of the apical third
Advance size 20 file to working length
Continue through sequence, seating each file to working length

64. Preparation of apical third
Progress from smaller to larger files
Each file is fully seated at working length
Small canals prepared to a minimum of ISO 35 or 40
Large canals prepared to a minimum of ISO 40 – 50

65. Preparation of apical third

66. Preparation of apical third

67. Preparation of apical third

68. Preparation of apical third

69. Preparation of apical third

70. Preparation of apical third

71. Preparation of apical third

72. Preparation of apical third

73. Preparation of apical third

74. Preparation of apical third

75. Preparation of apical third

76. Preparation of apical third

77. File kit on completion of instrumentation

78. Master Apical File (MAF)
The largest file that extends to working length
MAF film is exposed to confirm length and placement

79. Master Apical File For large canals – minimum MAF #40 - 50
For small canals – minimum MAF #

80. Master Apical File Take a radiograph with MAF in place. This confirms:
Length
Placement

81. Mission Accomplished