Anatomy of root apex

anatomy of root apex

1. 11/13/2018 1 Don’t just follow your dreams CHASE THEM . . . . Anatomy of Root Apex

2. Anatomy of Root Apex & it’s Clinical Significance Presented by: Dr Abhisek Guria Dept. of Conservative Dentistry & Endodontics SHDCH , Hassan Date of Presentation : 20/06/2018

3. 11/13/2018 3 Anatomy of Root Apex

4. Contents Introduction Development of root apex Accessory canal formation Root length & apical closure Apical root anatomy Apical constriction Topography of apical constriction Clinical significance CDJ Location & diameter Clinical significance 11/13/2018 4 Anatomy of Root Apex

5. 11/13/2018 5 Apical foramen Exit of AF Number of AF Size of AF Clinical significance Variations in morphology of apical third of the root & its significance in endodontics Accessory canals Areas of resorption Repaired resorption Pulp stones – attached, embedded & free Varied amount of irregular secondary dentin Anatomy of Root Apex

6. 11/13/2018 6 Radiographic Assessment Of Apical Third Types Of Root Apex Thin Pinched Apex Bulbous Apex Resorbed Apex Blunderbuss Apex Histology Of Apical Dentin And Pulp Termination Point For Root Canal Procedures Challenges Faced Due To Apical Third Anatomy During Endodontic Procedures Anatomy of Root Apex

7. 11/13/2018 7 Isthmus Classification Clinical Significance Working Width Shape & Size Of The Apical Preparation Preflaring Final Width Of Canal Root End Resection Extent Of Apical Resection Bevel Angle Anatomy of Root Apex

8. 11/13/2018 8 Procedural errors seen at the root apex Ledging Apical transportation Perforation Zipping Loss of patency Conclusion References Anatomy of Root Apex

9. Introduction Morphologically - most complex region Therapeutically - most challenging Prognostically - most important Radiographically - most obscure unclear area 11/13/2018 9 Anatomy of Root Apex

10. Mountain pass theory Kronfeld , 1939 Rationale for non surgical endodontic treatment Zone A: bacteria – invaders AF- mountain pass Zone B: granulomatous tissue at periapex - mobilized army Zone C: complete elimination of invaders 11/13/2018 10 Anatomy of Root Apex

11. Development of root apex

12. 11/13/2018 12 Begins after enamel & dentin formation reached future CEJ Anatomy of Root Apex

13. HERS Molds the shape of root Initiates radicular dentin formation 11/13/2018 13 Anatomy of Root Apex

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15. 11/13/2018 15 Epithelial Diaphragm & Apical foramen Anatomy of Root Apex

16. 11/13/2018 16 Disintegration of HERS Cells of dental sac comes in contact of dentin Deposition of cementum Odontobl a st Predentin Root dentin Dentino cemental Junction Pulp Cemento i d Cementum Cementoblast Cemento c y te Dental sac Dental sac cell Becoming a Cementoblast Formation of Periodontal ligament Epithelial rests Of Malassez Developing bone Anatomy of Root Apex

17. Cellular cementum at apical third Continues throughout life Maintains length of root Constricts apical foramen Deviates apical foramen Apical cementum is thicker than coronal third 11/13/2018 17 Anatomy of Root Apex

18. Video 11/13/2018 18

19. ACCESSORY CANAL FORMATION Source of collateral circulation for pulp More prevalent in apical third 11/13/2018 19 Defect in the epithelial root sheath Failure in the induction of dentinogenesis The presence of small blood vessels produce a gap - accessory canal Anatomy of Root Apex

20. APICAL CLOSURE Plays important role in repair of dental pulp following Endodontic Therapy Early in females Apical closure of Maxillary posterior is later than mandibular teeth ( Moorees et al 1963) 11/13/2018 20 Anatomy of Root Apex

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22. Apical root anatomy

23. Three anatomic & Histologic landmarks 11/13/2018 23 Anatomy of Root Apex

24. Apical constriction Narrowest diameter of the root canal with the smallest diameter of blood supply & preparation to this point results in a small wound site & optimal healing condition . ( Ricucci & Langeland ) usually occurs within the dentin Just prior to initial layer of cementum – called ‘’ MINOR DIAMETER’’ ( Kuttler ) 11/13/2018 24 Anatomy of Root Apex

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26. Mean perpendicular distance from the root apex to the apical constriction 11/13/2018 26 Mesiodistal (mm) Labiolingual (mm) 0.370 0.428 0.307 0.369 0.313 0.375 Teeth Vertical (mm) Central incisor 0.863 Lateral incisor 0.825 Canine 1.010 Mizutani T, Ohno N, Nakamura H. Anatomy of Root Apex

27. Briseno Marroquin et al did a study on Egyption population and concluded that Shape – oval (70%) High percentage of 2 physiologic foramina in Mesial root of mandibular ( 87%) Mesio -buccal root of maxillary first molar (71%) Morphology of the Physiological Foramen:I . Maxillary and Mandibular Molars VOL. 30, NO.5,MAY2004 11/13/2018 27 Anatomy of Root Apex

28. ROOT CANAL MORPHOLOGY 11/13/2018 Anatomy of Root Apex 28

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30. GULABIVALA Classification 11/13/2018 30 Anatomy of Root Apex

31. Topography of apical constriction ( Dummer ) 11/13/2018 31 Anatomy of Root Apex

32. 11/13/2018 32 Radiograph (A) and histologic section (B) of ideal apical constriction on tooth #7. Anatomy of Root Apex

33. 11/13/2018 33 Radiograph (A) and histologic section (B) of palatal root of tooth #15 with no apical constriction Anatomy of Root Apex

34. 11/13/2018 34 Radiograph (A) and histologic section (B) of mesial root of tooth #19 with apical foramen well short of radiographic apex. Anatomy of Root Apex

35. Clinical significance Canal preparation & obturation should terminate at minor diameter Provide a bottle neck area during obturation – rapid development of Apical dentin matrix Retaining filling material & sealers within the canal Painfree treatment can be done without damaging periapical tissue 11/13/2018 35 Anatomy of Root Apex

36. CDJ It is the point in canal where cementum meets dentin Where pulp tissue end and Pdl tissue begins Histological landmark, cannot be located clinically or radiographically 11/13/2018 36 Anatomy of Root Apex

37. Location & diameter Ponce & Vilar Fernandez et al evaluated histologic section of maxillary ant. To determine the location & diameter Extension differed considerably on opp. Canal wall Extend till same level in 5% Greatest extension on the concave side of canal curvature CDJ & AC are generally not coinciding with the same area 11/13/2018 37 Anatomy of Root Apex

38. Diameter of canal at CDJ was highly irregular Max. central incisor – 353 µm Lateral incisor – 292 µm Canines – 298 µm Located 0.5 - 3 mm short of the anatomic apex ( Tamse A,KaffeI , Fishel D, 1980) 11/13/2018 38 Anatomy of Root Apex

39. Clinical significance Theoretically , the CDJ is the appropriate apical limit for root canal treatment As at this point the area of contact between the periradicular tissues and root canal filling material is likely to be minimal (Palmer et al. 1971, Seltzer 1988, Katz et al. 1991, Ricucci & Langeland 1998) 11/13/2018 39 Anatomy of Root Apex

40. ‘’ theoretically ‘’ – because it is a histologic landmark Clinically impossible to identify Therefore, it cannot be an ideal landmark to use clinically as the end-point for root canal preparation and filling. 11/13/2018 40 Anatomy of Root Apex

41. Apical foramen (AF) Circumference or rounded edge, like a funnel or crater, that differentiates the termination of the cemental canal from the exterior surface of the root . ( Cohen)

42. Apical foramen (AF) From AC or Minor Diameter the canal widens as it approaches the AF or the Major Diameter Shape between AC & AF has been described as Funnel shaped Hyperbolic Morning glory 11/13/2018 42 Anatomy of Root Apex

43. 11/13/2018 43 Kuttler Anatomy of Root Apex

44. EXIT OF AF Doesn’t normally exit at the anatomic apex but is offset 0.3 – 0.5 mm Both root apex & AF of central incisors & canine showed distolabial displacement Lateral incisor – distolingual displacement ( Mizutani et al) 11/13/2018 44 Anatomy of Root Apex

45. AF situated directly at the apex in maxillary centrals, laterals, cuspids , first premolars and mandibular second premolars AF coincide less frequently In the maxillary molars and all the mandibular teeth with the exception of the 2 nd PM . GREEN(1955 1956 1960) 11/13/2018 45 Anatomy of Root Apex

46. Number of AF Morfis et al studied apices of 213 permanent teeth with SEM & determined : > 1 AF was observed in all teeth except for distal root of mand . Molars & palatal root of max. molars Highest % of multiple AF was observed in Mesial root of mand molars - 50% Maxillary premolars – 48.3% Mesial root of max molars – 41.7 % 11/13/2018 46 Anatomy of Root Apex

47. Size of AF All groups of teeth exhibited at least 1 accessory foramina Max. premolars have largest no & size of accessory foramen (53.4um) with most complicated apical makeup Followed by mand . premolars 11/13/2018 47 Anatomy of Root Apex

48. Size of main apical foramina 11/13/2018 48 Teeth Mean values ( u ) Maxillary incisors 289.4 Mandibular incisors 262.5 Maxillary premolars 210.0 Mandibular premolars 268.2 Maxillary molars Palatal 298.0 Mesiobuccal 235.05 Distobuccal 232.20 Mandibular molar Mesial 257.5 Distal 392.0 * Results published previously in: Morfis A, Sylaras SN, Georgopoulou M, Kernani M, Prountzos F. Study of the apices of human permanent teeth with the use of a scanning electron microscope. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1994: 77(2):172–176. Anatomy of Root Apex

49. Clinical significance Inadequate knowledge and mismanagement of apical foramen may affect long and short term success of RCT May change due to functional influences- occlusal pressure, mesial drift 11/13/2018 49 Anatomy of Root Apex

50. Variations in morphology of apical third of the root & its significance i Major et al found tremendous variations in morphology of apical region of root Accessory canals Areas of resorption Repaired resorption Pulp stones Varied amount of irregular secondary dentin 11/13/2018 50 Anatomy of Root Apex

51. 1. Accessory canals Accessory canal branches off from the main root canal in the apical region Lateral canal is located at right angles to main root canal Furcation canal seen at furcation Formed when the root sheath disintergrates when dentin is elaborated 2. lack of dentin formation around a blood vessel 11/13/2018 51 Anatomy of Root Apex

52. 11/13/2018 52 Ti s s u e -fi b r o b l ast s , collagen fibres , nerves, macrophages (resemble CT of PDL rather than pulp) Lateral canals are more common in bifurcation and trifurcation region of molars Anatomy of Root Apex

53. 11/13/2018 53 accesory canals have a mean diameter of 6- 60 µm ( HESS et al, 1963) Accessory canals form apical deltas in the root apex In distal root of mandibular molars and palatal of maxillary molars –these canals fan out towards the apex in a canoe –shaped arrangement Anatomy of Root Apex

54. 11/13/2018 54 Shows 3 distinct patterns in the mandibular first molars. In 13% a single furcation canal extends from the pulp chamber to the intraradicular region. In 23% lateral canals extends from the coronal third ( 80% extend from the distal root canal). C. About 10% have both lateral and furcation canals . Anatomy of Root Apex

55. Apical delta Y shaped branching of root canal near apex. Difficult to instrument & obturate Mostly not visible in radiograph 11/13/2018 55 Anatomy of Root Apex

56. Clinical significance No of accessory canals – not a significant factor in success of endodontic therapy following endodontic therapy in teeth with vital pulps they become obliterated by the deposition of cementum In non-vital teeth, inflammatory tissue will get resorbed and replaced with uninflammed connective tissue . (Hess 1983) 11/13/2018 56 Anatomy of Root Apex

57. They are avenues for interchange of metabolic and breakdown products between pulp and periodontal tissue 11/13/2018 57 If present in the floor of pulp chamber they transmit toxins and irritants from pulp Establish a lesion in furcation which may appear radiographically as periodontal disease Anatomy of Root Apex

58. 11/13/2018 58 They are usually not detected in intraoral radiographs They may become noticeable subsequent to the necrotization of the main canal Thickening of the PDL or development of a frank lesion in the lateral wall of the root Become apparent in the post –obturation x-ray where radio-opaque material is seen extending to surface of root Anatomy of Root Apex

59. 11/13/2018 59 Presence of these canals emphasize the need for employing effective irrigation solution and technique and also three dimensional filling of root canal Anatomy of Root Apex

60. 11/13/2018 60 When the pulp is extirpated from a vital tooth , pulp stump may remain in these canals –causing post- pulpectomy pain and also pain felt when sealer is pushed into these canals Anatomy of Root Apex

61. 11/13/2018 61 May harbour micro organisms and continue to irritate periapex Lesion may grow despite radiographic evidence of proper filling of principal canal. Require periapical surgery Anatomy of Root Apex

62. 11/13/2018 62 Although the incidence of occurrence of these canals is high – the percentage of failures due to unfilled canals is small in clinical practice because of the biological hard tissue closure (cementum) subsequent to the elimination of chronic inflammation and irritants from main canal Anatomy of Root Apex

63. 2. Areas of resorption Shallow resorption of dentin in apical portion Resorption of cementum and dentin occurs on the body of the root also at the periapical region 11/13/2018 63 Mainly due to Orthodontic tooth movement Inflamation of apical pulp & periodontal tissue Anatomy of Root Apex

64. Resorption widens apical foramen As inflammation subsides , repair of resorbed region occurs by deposition of secondary cementum As a result position of AF shifts laterally 11/13/2018 64 Anatomy of Root Apex

65. 3. Pulp stones / denticles Formed around the foci of mineralizing pulp tissue components Can be free, attached or embedded In the apical third 15 % of the teeth shows denticles 11/13/2018 65 Anatomy of Root Apex

66. Apical calcification In chronic inflammation & aging, calcification of the canal occurs In some cases only apical 1/3 rd is calcified- obturation become difficult Effort should be made to negotiate with EDTA & thin files 11/13/2018 66 Anatomy of Root Apex

67. 4. Varied amounts of irregular secondary dentin Deposited continuously by the radicular pulp tissue Twards the apex, the dentinal tubules appear to blend with cementum canaliculi Continuous deposition will reduce the size of AF , but complete closure doesn’t occure as long as vital pulp present 11/13/2018 67 Anatomy of Root Apex

68. Canal curvature Apical third of roots are complex also in curvature Usually show a distal curvature A buccal or lingual curvature may not be discernible in radiograph 11/13/2018 68 Anatomy of Root Apex

69. Clinical management 11/13/2018 69 Anatomy of Root Apex

70. Learn everything you can, anytime you can, from anyone you can. There will always come a time when you will be grateful you did. - sarah caldwell

71. Anatomy of Root Apex & it’s Clinical Significance Presented by: Dr Abhisek Guria Dept. of Conservative Dentistry & Endodontics SHDCH , Hassan Date of Presentation : 22/06/2018

72. 11/13/2018 72 Edward Maynard (1813- 1891) pioneer of endodontic hand instruments Anatomy of Root Apex

73. Contents Introduction Development of root apex Accessory canal formation Root length & apical closure Apical root anatomy Apical constriction Topography of apical constriction Clinical significance CDJ Location & diameter Clinical significance 11/13/2018 73 Anatomy of Root Apex

74. 11/13/2018 74 Apical foramen Exit of AF Number of AF Size of AF Clinical significance Variations in morphology of apical third of the root & its significance in endodontics Accessory canals Areas of resorption Repaired resorption Pulp stones – attached, embedded & free Varied amount of irregular secondary dentin Anatomy of Root Apex

75. 11/13/2018 75 Root canal morphology Measurement of canal curvature Radiographic Assessment Of Apical Third Types Of Root Apex Thin Pinched Apex Bulbous Apex Resorbed Apex Blunderbuss Apex Histology Of Apical Dentin And Pulp Termination Point For Root Canal Procedures Challenges Faced Due To Apical Third Anatomy During Endodontic Procedures Anatomy of Root Apex

76. 11/13/2018 76 Isthmus Classification Clinical Significance Working Width Shape & Size Of The Apical Preparation Preflaring Final Width Of Canal Root End Resection Extent Of Apical Resection Bevel Angle Anatomy of Root Apex

77. 11/13/2018 77 Procedural errors seen at the root apex Ledging Apical transportation Perforation Zipping Loss of patency Conclusion References Anatomy of Root Apex

78. ROOT CANAL MORPHOLOGY 11/13/2018 Anatomy of Root Apex 78

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80. GULABIVALA Classification 11/13/2018 80 Anatomy of Root Apex

81. Canal curvature 11/13/2018 81

82. Schneider’s method Mild < 5 Moderate 10 -20 Severe > 20 11/13/2018 82 Journal of Restorative Dentistry / Vol - 3 / Issue - 3 / Sep-Dec 2015 • 59 Anatomy of Root Apex

83. Weine’s method 11/13/2018 83 Journal of Restorative Dentistry / Vol - 3 / Issue - 3 / Sep-Dec 2015 • 59 angle is measured at the point of intersection between the two lines Anatomy of Root Apex

84. Lutein method Modification of Schneider’s method 11/13/2018 84 Journal of Restorative Dentistry / Vol - 3 / Issue - 3 / Sep-Dec 2015 • 59 Anatomy of Root Apex

85. Cunningham’s and Senia’s method focuses on multiple root curvatures, that is, S‑shaped canals angle is measured separately at the coronal and apical ends Angle X – AB & BC Angle Y – BC & CD 11/13/2018 85 Journal of Restorative Dentistry / Vol - 3 / Issue - 3 / Sep-Dec 2015 • 59 Anatomy of Root Apex

86. Danger zone & Safe zone 11/13/2018 86 Anatomy of Root Apex

87. 11/13/2018 87 Anatomy of Root Apex

88. Radiographic assessment of apical third Root canal that descends from the pulpal floor & suddenly stops in the apical region To confirm, a 2 nd radiograph exposed from mesial / distal angulation Shows vertical lines indicating peripheries of additional root surfaces 11/13/2018 88 Anatomy of Root Apex

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90. Radiolucent line running along the diagnostic instrument whose long axis is not in relation to the instruments – additional canal 11/13/2018 90 Anatomy of Root Apex

91. CT 11/13/2018 91 Anatomy of Root Apex

92. Types of root apex 11/13/2018 92 THIN PINCHED APEX proper care required during instumentation Over enlargement may lead to perforation Anatomy of Root Apex

93. 11/13/2018 93 BULBOUS APEX usually due to hy p erceme n tosis proper care required during length determination Apical constriction is significantly shorter from radiographic apex Anatomy of Root Apex

94. 11/13/2018 94 RESORBED APEX caused due to advanced inflammation at the periapex resorption of cementum and dentin and widening of apical foramen WL determination ,preparation and condensation of guttapercha is difficult - Preparation should stop 1-2mm short of radiographic apex Anatomy of Root Apex

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96. 11/13/2018 96 newly erupted tooth showing open apex therapy BLUNDERBUSS APEX An incompletely formed root having a wide canal pulp may get necrosed due to caries or trauma and may require root canal therapy standard instrumentation and obturation techniques are not favorable Anatomy of Root Apex

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98. HISTOLOGY OF APICAL DENTIN AND PULP

99. APICAL PULP TISSUE 11/13/2018 99 Anatomy of Root Apex

100. APICAL DENTIN 11/13/2018 100 Anatomy of Root Apex

101. TERMINATION POINT FOR ROOT CANAL PROCEDURES Controversial Clinical determination of apical morphology is difficult Existence of apical constriction is more conceptual than real Traditional single apical constriction present in less than half the time when apical root resorption & periapical pathosis is factor ( Dummer et al ) 11/13/2018 101 Anatomy of Root Apex

102. Weines recommendation 11/13/2018 102 Anatomy of Root Apex

103. Wu et al It is difficult to locate AC or AF clinically, so radiographic apex is more reliable point For vital teeth point of termination = 2-3mm short of apex Apical pulp stem prevents extrusion of irritating material to periapex For necrotic pulp 2 mm short of apex Shorter than 2mm decline success rate by 20% In retreatment case 1-2 mm short of apex 11/13/2018 103 Anatomy of Root Apex

104. Most favorable prognosis – Apical constriction Worst prognosis – beyond AC Sealer or GP in periapex , lateral canals always caused severe inflammatory reaction ( Langeland & Ricucci ) Lim & Stock stated that 0.3mm of dentin approx. is the minimal canal wall thickness that should remain after prep in order to provide sufficient resistance to obturation forces 11/13/2018 104 Anatomy of Root Apex

105. Challenges faced due to apical third anatomy during endodontic procedures The initial file chosen for exploring the canal anatomy & for binding in canal is used as measure of apical diameter This does not accurately gauge the size of oval shaped canal 11/13/2018 105 Mandibular first premolar with three separate roots trifurcating at midroot . B, Radiograph of three views. Anatomy of Root Apex

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108. ISTHMUS It is a narrow ribbon shaped communication b/w 2 root canals that contains pulp or pulpally derived tissue They can act as bacterial reservoir They must be found, prepared & filled Any root with 2 or more canals may have an isthmus 11/13/2018 108 Anatomy of Root Apex

109. 11/13/2018 109 A complete or partial isthmus was found at 4mm level (100%) In another study , partial isthmus was found more often than complete isthmi Identification & treatment of isthmus are vital in success of surgical procedures Evangelos et al Braz Dent J (2010) 21 (5): 428-431 Anatomy of Root Apex

110. Classification ( Kim et al ) 11/13/2018 110 Anatomy of Root Apex

111. Clinical significance 11/13/2018 111 Anatomy of Root Apex

112. 11/13/2018 112 Anatomy of Root Apex

113. working width Objective of RCT – minimize no of microbes & pathologic debris

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116. 11/13/2018 116 Difficult to investigate horizontal dimension as it varies greatly at each vertical level “forgotten dimension” preparing each canal to a specific apical diameter as per its initial apical size may better equip the clinician to provide a more predictable canal preparation . Horizontal dimension of RC system more complicated than vertical Anatomy of Root Apex

117. SHAPE Kuttler (1955) & Mizutani et al (1992) oval, long oval, ribbon shaped or round Wu et al (2000) – 25% of AC had long oval shape Apic a l con st r uction i s no t un i for mly round , oval or irregular 11/13/2018 117 Anatomy of Root Apex

118. Size of the apical preparation: 11/13/2018 118 Anatomy of Root Apex

119. Preflaring Studies have reported that initial flaring before determining the apical size may give a more accurate measurement of the apex Apical diameter proved to be at least one file size bigger once preflaring was done. Tan BT, Messer HH . The effect of instrument type and preflaring on apical file size determination. Int Endod J 2002;35:752– 8. 11/13/2018 119 Anatomy of Root Apex

120. 11/13/2018 120 The apical size to be two file sizes bigger after preflaring with Gates-Glidden drills. The instrument used for preflaring played a major role in determining the anatomical diameter at the WL Contreras MA, Zinman EH, Kaplan SK. Comparison of the first file that fits at the apex, before and after early flaring. J Endod 2001;27:113– 6. Pecora JD, Capelli A, Guerisoli DM, Spano JC, Estrela C. Influence of cervical preflaring on apical file size determination. Int Endod J 2005 Anatomy of Root Apex

121. Final width of canal

122. The classic test for determining correct width finding of clean, white dentin shavings on the flutes of the reamers and files. But, d o e s n o t n e c e s s a rily indi c ate t h o rou g h removal of tissue, debris, and affected dentin 11/13/2018 122 Anatomy of Root Apex

123. Many canals are oval or ribbon shaped in cross section. Clean, white dentin shavings are attainable from walls close to each other, but the far walls may be completely untouched while this sign is obtained 11/13/2018 123 Anatomy of Root Apex

124. Earlier research has shown that canals needed to be enlarged to at least #35 file for adequate irrigation to reach the apical third Salzgeber RM, Brilliant JD. An in vivo evaluation of the penetration of an irrigating solution in root canals. J Endod 1977 11/13/2018 124 Anatomy of Root Apex

125. 11/13/2018 125 a #25 file was as efficient as a #40 file for reducing residual microorganisms. Yared GM, Dagher FE. Influence of apical enlargement on bacterial infection during treatment of apical periodontitis. J Endod 1994 Buchanan (2001) has advocated minimal apical preparation (e.g. #20 or #25) based on his clinical opinions. He proposed that enlarging the canal size would cause apical transportation or zips . These techniques focus more on minimal apical preparation for the prevention of iatrogenic errors Anatomy of Root Apex

126. A 4-6 year clinical study on endodontic outcomes favored smaller preparation sizes with tapered shapes to larger shapes. 90% and 80% success rate respectively Treatment outcomes in Endodontics: the Toronto Study. Phase I and II. Friedman et al Journal of Endodontics 2004; 30:9 11/13/2018 126 Anatomy of Root Apex

127. An apical preparation size 20 would be inferior to size 30 and 40 regarding canal debridement but a larger taper (0.10) may potentially compensate for smaller sizes. Baumgartner et al. influence of instrument size on root canal debridement Journal of Endodontics 2004;30:110 11/13/2018 127 Anatomy of Root Apex

128. based on microbiological assays found that apical preparation to size 30 is required to effectively clean root canals Mickel AK, Chogle S, Liddle J. The role of apical size determination and enlargement in the reduction of intracanal bacteria. Journal of Endodontics 2007; 33:21 11/13/2018 128 Anatomy of Root Apex

129. Large , small or Adequate ? 11/13/2018 Anatomy of Root Apex 129

130. Reduction of intracanal bacteria using NiTi rotary instruments & various medications 11/13/2018 Anatomy of Root Apex 130

131. Root canal irrigants 11/13/2018 Anatomy of Root Apex 131

132. ROOT END RESECTION

133. Extent of apical resection 3mm apical resection –to eliminate most of lateral canals and apical deltas 11/13/2018 133 Anatomy of Root Apex

134. Bevel angle Earlier 45 degree bevel angle placed to bring apical foramen labially At present 0-10 degree benefit of microsurgical procedures 11/13/2018 134 Anatomy of Root Apex

135. Advantages Minimizes removal of excess buccal cortical plate Exposes fewer dentinal tubules thus preventing excess leakage and contamination 11/13/2018 135 Anatomy of Root Apex

136. 11/13/2018 136 Leakage through dentinal tubules originating at the beveled root surface. Reverse filling does not extend coronally to the height of the bevel. Reverse filling extends coronally to the height of the bevel, blocking fluid penetration (arrows) into the root canal space. Anatomy of Root Apex

137. Case report A, clinical photograph of a 34-year-old man with swelling in the buccal furcation area of his mandibular right first molar, tooth #30. He gives a history of previous root canal treatment with silver cones that required retreatment B, preoperative radiograph. 11/13/2018 137 Anatomy of Root Apex

138. 11/13/2018 138 C and D , After root resection , inspection of the root and root tip is important. Note the accessory canals associated with the root tip. E , clinical photograph taken after root end resection and filling. Note the perpendicular resection as well as the pathologic defect. F , radiograph of the completed root end filling Anatomy of Root Apex

139. 11/13/2018 139 . G and H , A 1-year recall photograph and radiograph demonstrate resolution of the lesion and osseous regeneration. Anatomy of Root Apex

140. PROCEDURAL ERRORS SEEN AT THE ROOT APEX some due to inattention to detail, and others totally unpredictable

141. LEDGING Any deviation from the original canal curvature results in the formation of a ledge. CAUSES Inadequate access cavity preparation False estimation of pulp space direction Failure to pre-curve SS instruments Failure to use instruments in a sequential manner Attempt to retrieve separated instruments Attempt to prepare calcified canals 11/13/2018 141 Anatomy of Root Apex

142. Relationship between the degree of curvature and incidence of ledge formation 11/13/2018 142 Journal of Restorative Dentistry / Vol - 3 / Issue - 3 / Sep-Dec 2015 • 61 Anatomy of Root Apex

143. 11/13/2018 143 Recognition: instrument can no longer be inserted into the canal to full working length Correction: Pre-curved No. 10 file is used to bypass U se a lubricant , irrigate frequently to removal dentin chip, Using short file strokes press the instrument against the canal wall where the ledge is located. Prevention: Pre-curving instruments and not “forcing ” them in Anatomy of Root Apex

144. APICAL transportation Moving the position of the canal’s physiologic terminus to a new iatrogenic location on the external root surface Correction: MTA is barrier of choice In severe cases where barrier technique cant be created corrective surgery is required 11/13/2018 144 Anatomy of Root Apex

145. Prevention: Don’t use large instrument initially. Correct determination of working length 11/13/2018 145 Anatomy of Root Apex

146. PERFORATION An artificial opening in a tooth or its root , created by boring, piercing or cutting, which results in a communication between the pulp space and the pdl tissues Incidence 3-10% 11/13/2018 146 Anatomy of Root Apex

147. Level: More apical the perforation, more favorable the prognosis. Size: Perforation size greatly affect the clinician’s ability to establish a hermetic seal. Mathematically described as -  r 2 (r = radius). Time: should be repaired as soon as possible to discourage further loss of attachment and prevent sulcular breakdown . 11/13/2018 147 Anatomy of Root Apex

148. Treatment sequence: Should be repaired before proceeding with definitive endodontic treatment. 1. Haemostatics : e.g. Calcium hydroxide, collagen, ferric sulfate, leave a coagulum behind that may promote bacterial growth compromising the seal 11/13/2018 148 Anatomy of Root Apex

149. 2. Barrier Material: Resorbable : Collagen materials: ( Collacote ) Calcium sulfate: ( Capset ) Non Resorbable : MTA 11/13/2018 149 Anatomy of Root Apex

150. Apical perforations Through the apical foramen or through the body of the root. Etiology: Instrumentation of canal beyond the apical foramen. Incorrect WL or inability to maintain proper WL causes blowing out of the apical foramen Treatment: Establish a new WL The new WL should be established 1- 2mm short of the point of perforation . 11/13/2018 150 Anatomy of Root Apex

151. Zipping or ELLIPT I C A TION Transportation or transposition of the apical portion of the canal 11/13/2018 151 Anatomy of Root Apex

152. 11/13/2018 152 L e d g e Zipping Perforation Anatomy of Root Apex

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154. LOSS OF PATENCY Canal may suddenly loose patency during a cleaning and shaping process. Causes Tissue compression, Debris accumulation or Instrument separation. 11/13/2018 154 Anatomy of Root Apex

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156. Conclusion The morphological variation & technical challenges involved in treatment of apical third is infinite The crux of endodontics revolves around efficient & effective manipulation & obturation of apical third So endodontist should have detailed knowledge of the anatomic variation and mechanical challenges involved for effective & efficient management during endodontic therapy 11/13/2018 156 Anatomy of Root Apex

157. Referrences Pathways of pulp – cohen Endodontic therapy – weine Oral histology – Orbans www. Google.com 11/13/2018 157 Anatomy of Root Apex

158. Thank you.. What you think about yourself matters more than what others think about you.