Locating The MB2 Canal Made Easy: Step-by-Step Technique — Transcript

Full transcript

1. 0:00Hey everyone, welcome back to the
2. 0:01channel. Today um we're going to dive
3. 0:04into a really important topic in
4. 0:05endodontics, the consequences of an
5. 0:08untreated MB2 canal, as well as uh how
6. 0:11to locate, diagnose, and treat it
7. 0:14effectively. It's like one of those
8. 0:15topics that can uh really make or break
9. 0:18the success of root canal therapy. So um
10. 0:20let's walk through everything you need
11. 0:22to know. First off, let's talk about
12. 0:24what happens if we uh miss the MB2 canal
13. 0:27during treatment. So in vital teeth with
14. 0:30irreversible pulpitis, leaving the MB2
15. 0:32untreated can like lead to persistent
16. 0:35pain, especially in response to thermal
17. 0:37stimuli. So your patient might come back
18. 0:40complaining of uh sensitivity or
19. 0:42discomfort even though you've already
20. 0:43treated the main canals. And um in
21. 0:46necrotic teeth it gets even trickier
22. 0:48because the untreated MB2 can can act as
23. 0:51a bacterial reservoir increasing the
24. 0:53risk of periapical infection and uh
25. 0:56ultimately treatment failure. Studies
26. 0:58consistently show that untreated MB2
27. 1:00canals are like a major cause of
28. 1:02persistent apical pathology and
29. 1:04retreatment cases which really uh
30. 1:07emphasizes how crucial it is to locate
31. 1:09and treat that canal properly. Now, some
32. 1:13clinicians might think that if MB2 is
33. 1:15like covered by a dentin shelf, it's
34. 1:17sealed off from bacteria and doesn't
35. 1:18matter much, but uh that's not really
36. 1:20the case. Back in 1917, Dr. Hess
37. 1:24actually showed that MB1 and MB2 canals
38. 1:26are interconnected by um ismisses,
39. 1:30meaning that bacteria from MB1 can like
40. 1:32easily spread to MB2 and vice versa. So,
41. 1:35even if you think MB2 is hidden and
42. 1:36isolated, it's probably uh still
43. 1:39infected if MB1 was. Clinical studies
44. 1:42have shown that periapical lesions often
45. 1:44center around an untreated MB2 canal
46. 1:46which is like why it's so critical to
47. 1:48locate and manage it properly. One of
48. 1:51the best tools we have today to um help
49. 1:54identify an untreated MB2 is combuted
50. 1:56tomography or CBCT. CBCT imaging gives
51. 2:00us like a clear view of the entire root
52. 2:02canal system and it can highlight
53. 2:05untreated MB2 canals especially when you
54. 2:07see a periodical lesion aligned
55. 2:09perfectly with the MB2's apical exit.
56. 2:12When that happens you know that
57. 2:14persistent infection is like probably
58. 2:15coming from that untreated canal. In
59. 2:17these cases non-surgical retreatment or
60. 2:20um even apicoctomy might be needed to
61. 2:23resolve the issue. So um how common is
62. 2:26MB2 in maxillary mers? Well in maxillary
63. 2:30first mers it's like present in about 90
64. 2:32to 95% of cases. In second mers it's
65. 2:36less common but um still significant
66. 2:38enough that you should be vigilant every
67. 2:40time you treat these teeth. Let's talk
68. 2:42about the actual location of MB2 and
69. 2:45some of the anatomy you need to like
70. 2:46keep in mind. MB2 is generally palatal
71. 2:49to MB1 but it doesn't necessarily line
72. 2:51up with the palatal canal. In first mers
73. 2:54MB2 usually sits about 1 to 3 millm
74. 2:57palatal to MB1. Now in addition to that
75. 3:00MB2 often lies in line with the messial
76. 3:02buckle groove of the chamber floor which
77. 3:05um can help you locate it. Also it
78. 3:08sometimes sits slightly messial to an
79. 3:10imaginary line drawn between MB1 and the
80. 3:12palatal canal. So um using that as a
81. 3:15guide can help orient you during
82. 3:17exploration. In second mers it tends to
83. 3:20be even closer to MB1 than in first
84. 3:22mers. Now about the denton shelf. This
85. 3:25is um especially relevant in middle-aged
86. 3:28and older patients. Over time MB2 can
87. 3:31get buried under a layer of secondary
88. 3:32denton forming what we call the denton
89. 3:34shelf. That denton shelf has to be uh
90. 3:37removed carefully otherwise MB2 stays
91. 3:39hidden and uninstrumented. And if you
92. 3:42don't remove it, you simply like can't
93. 3:43access or clean the canal. The
94. 3:46configuration of MB2 can also vary.
95. 3:49Sometimes MB1 and MB2 um remain separate
96. 3:52all the way to the apex, but in other
97. 3:54cases they converge before reaching the
98. 3:56apex, forming an ovoid or figure 8
99. 3:58shaped orifice. That's why it's like so
100. 4:01important to confirm the final canal
101. 4:02morphology using magnification and uh if
102. 4:05needed CBCT before you complete the
103. 4:08treatment. So, um, let's walk through a
104. 4:11typical clinical approach to finding and
105. 4:12treating MB2. First, you need proper
106. 4:15magnification and illumination, a
107. 4:18microscope or like at least good loops
108. 4:20with an LED light. Make sure you have
109. 4:22good access to the pulp chamber before
110. 4:24you start searching for MB2 and um,
111. 4:27remove any obstructions like
112. 4:28calcifications or the denton shelf if
113. 4:31necessary. Once that's done, identify
114. 4:33MB1 and uh, use it as a landmark. MB2 is
115. 4:37usually about 1 to 3 millimeters palatal
116. 4:39to MB1. Remember that in many cases it
117. 4:42lies along the messial buckle groove of
118. 4:44the chamber floor and can even be like
119. 4:46slightly messial to the imaginary line
120. 4:49connecting MB1 and the palatal canal. So
121. 4:51keep that in mind as you explore. So if
122. 4:54you can't see it directly, gently
123. 4:56explore the area with endodonic explorer
124. 4:58like a DG16 or a micro explorer.
125. 5:01Sometimes MB2 is um completely hidden
126. 5:04under the Denton shelf. In those cases,
127. 5:07you'll need to carefully trough in a
128. 5:08palatable direction using a slow speed
129. 5:10round burr or a Mueller bur. The key is
130. 5:13to be conservative. Don't be too
131. 5:16aggressive or uh you risk perforation.
132. 5:19In cases with significant calcification,
133. 5:21you might need to trough about 1 to 2
134. 5:23millm apically to find MB2. Once you
135. 5:26locate MB2, gently probe it with a small
136. 5:28K file, usually a size 068 or 10, and
137. 5:32confirm patency. At this stage, you want
138. 5:34to like establish a glide path before
139. 5:36you proceed with instrumentation. It's
140. 5:39also important to confirm whether MB2 is
141. 5:41independent or merges with MB1. And um
142. 5:44you can do that with a working length
143. 5:46radioraph or CBCT imaging. When you're
144. 5:49ready for instrumentation, use a crown
145. 5:52down technique to uh gradually enlarge
146. 5:54the canal. Frequent irrigation with
147. 5:56sodium hypocchlorite and EDTA is
148. 5:58essential to remove debris and disinfect
149. 6:00the canal. You might even consider using
150. 6:03ultrasonic activation to like enhance
151. 6:05irrigant
152. 6:06penetration. When it comes time to
153. 6:08opterate, if MB1 and MB2 remain
154. 6:10separate, you need to fill both canals
155. 6:12individually. If they merge, you need to
156. 6:15make sure the sealer flows adequately
157. 6:16into the merged section. techniques like
158. 6:19warm vertical compaction or uh
159. 6:21carrierbased opteration can help ensure
160. 6:23a proper seal and reduce the risk of
161. 6:25future
162. 6:26leakage. And um finally, sometimes
163. 6:30despite your best efforts, you just
164. 6:32can't locate MB2. In those cases, it's
165. 6:35really important to refer the patient to
166. 6:37a specialist, an endodontist, who has
167. 6:40the equipment and expertise to manage
168. 6:42complex cases. If the tooth is severely
169. 6:44calcified, you might need an endodonic
170. 6:46microscope and CBCT imaging to like
171. 6:49locate MB2 accurately. In some cases, a
172. 6:52pulpctomy can be done as an interim
173. 6:54measure to relieve symptoms before
174. 6:56referral. So, that's the overview of the
175. 6:59clinical importance of MB2 canals from
176. 7:02the consequences of missing them to the
177. 7:05diagnostic tools and the step-by-step
178. 7:07approach to finding and treating them.
179. 7:10Thanks for tuning in and if you found
180. 7:12this helpful, please like, hit that like
181. 7:14button and subscribe for more dental
182. 7:16deep dives. See you in the next video.