1. Cleaning & Shaping Dr. Ashraf Refai BDS MSc DD HMD Lecturer of Endodontics Al-Azhar University / MIU www.arefai.edublogs.org

2. Why Should We Clean & Shape? Any Ideas???

3. Objectives of Cleaning & Shaping

4. Mechanical Objectives Create a continuous taper with the narrowest part apically and the widest part coronal. Preserve the natural curvature of the canal Preservation of the apical foramen Creation of an apical stop (seat) Objectives of Cleaning & Shaping

5. Biological Objectives Total removal of organic and inorganic debris in root canal system Disinfection of the root canal system Do no harm the tooth or the periodontium Objectives of Cleaning & Shaping

6. Outline Form Resistance Form Retention Form Extension For prevention Toilet of Cavity (Irrigation) Principles of Radicular Cavity Preparation

7. Canals are wider in one dimension and not the other The cross-section of the canal is rarely rounded There are high percentages of extra canals Lateral & Accessory canals do exists All canals have a degree of curvature Complex Anatomy that Should be Considered

8. The Myth of the GeometricallyTapered & Straight Canal

9. Preparation for Root CanalEnlargement

10. Proper coronal cavity preparation Tooth Length Determination Apical Constriction (o.5 to 1mm) Minor Diameter Major Diameter Preparation for Root Canal Enlargement

11. Radiographic Method (Ingle’s Method) Tentative length Reduction of estimated length Placement of the instrument in the canal Exposure of a radiograph Adjustment of the length Retake the radiograph (If necessary) Methods of Tooth Length Determination(Preparation for Root Canal Enlargement)

12. The Radiographic Method

13. The SLOB RULE SLOB Buccal Opposite Lingual Same

14. Apex Locators Used in combination with the radiographic techniques Methods of Tooth Length Determination(Preparation for Root Canal Enlargement)

15. How Does it Work???

16. Different Apex Locators

17. Pulp extirpation & tissue debridement Irrigation (Chemical) The rule is As much as you can As many times as you can Preparation for Root Canal Enlargement

18. Functions of an Irrigant To physically flush debris Tissue solvent Antibacterial agent Lubricant Irrigation (Preparation for Root Canal Enlargement)

19. Irrigation (Preparation for Root Canal Enlargement)

20. Types of Irrigants Sodium Hypochlorite (NaOCl) Preferred irrigant Used in full concentration or half concentration 5.25% or 2.625% Excellent tissue solvent Can be combined with H2O2 Best results alternating with EDTA Irrigation (Preparation for Root Canal Enlargement)

21. Types of Irrigants Ethylene Diaminetetracetice Acid (EDTA) Strong chelating agent Strong antibacterial agent Not a tissue solvent Types: RC prep & Glyde Available in gel form Irrigation (Preparation for Root Canal Enlargement)

22. Types of Irrigants Hydrogen Peroxide 3% (H2O2) Nascent oxygen (Antibacterial) Effervescence or Bubbling action Irrigation (Preparation for Root Canal Enlargement)

23. Types of Irrigants ChlorohexidineGluconate 0.2% Comparable to NaOCl but without tissue solvent capability Quaternary Ammonium Compounds Antiseptic, not a tissue solvent, low toxicity Irrigation (Preparation for Root Canal Enlargement)

24. Preparation for Root Canal Enlargement Method Of Irrigation

25. Steps of Root Canal Enlargement

26. Root Canal Enlargement(Hand Instruments)

27. Root Canal Enlargement(Instrument Motions) Push & Pull Reaming Turn & Pull Watch Winding Balanced Force

28. Root Canal Enlargement(Techniques: Direction & Sequence) Step Back Technique

29. Why do we clean & shape? Mechanical Objectives Biological Objectives The Myth of the Geometric Canal Preparation for root canal enlargement Proper access Tooth length determination Irrigation Functions of an irrigant Ideal properties of an irrigant Types of irrigants Components of a preparation technique Step-Back Technique Mid Lecture Revision

30. Root Canal Enlargement(Techniques: Direction & Sequence) Crown Down Technique

32. For canal packing with dentin debris

33. For ledges and perforations

34. For canal straightening

35. For instrument breakage

36. For loss of operator tactile senseHistorically they were not widely accepted

37. Root Canal Enlargement(Engine Driven Instruments) With the introduction of NiTi instruments attitudes changed

40. Always use an Irrigant

41. Never skip files

42. Never force files

43. Precurve your files

44. Anticurvature filing

45. Use hybrid techniques (Enlarge coronally first)

48. When there is sufficient resistance form (3 sizes above the initial file)

50. Procedural Errors During Cleaning & Shaping

52. When there is sufficient resistance form (3 sizes above the initial file)

54. Clinical Appearance: Can’t reach working length

55. Etiology:

56. Insufficient irrigation

57. Lack of recapitulation

58. Management:

60. Clinical Appearance:

61. Loss of working Length

62. Solid blockage

63. File out of path radiographically

64. Etiology:

65. Insufficient irrigation

66. Lack of recapitulation

67. Using large size instrument in narrow canals

68. Skipping files

71. Clinical Appearance:

72. Sudden pain

73. Bleeding into the canal

75. Etiology:

76. Coronal Perforation: Over-Enlargement of the canals

77. Furcation Perforation:Failure of locating the canals

78. Mid-root Perforation: Over-Enlargement & lack of precurving

81. Treatment:

82. Coronal Perforation: Filling of the perforation

83. Furcation Perforation:Repair

84. Mid-root Perforation: Renegotiation of the canal and the obturation & follow up

86. Clinical Appearance:

87. Loss of working length

88. Missing piece of the instrument

90. Etiology:

91. Using Excessive force

92. Failure to inspect instrument

94. Treatment:

95. Removal of the fragment with ultrasonics

96. Bypass the instruments