Why Orifice Directed Access Beats Straight-Line in Root Canals — Transcript

Full transcript

1. 0:00If you'd like to know how to periform endodontic therapy in 2026, then stick
2. 0:04around till the end of the video.
3. 0:14If you're new to the channel.
4. 0:15My name's Siju Jacob.
5. 0:16I've been a private practitioner in Bangalore and Dubai for the past 25 years.
6. 0:21I've been using a surgical microscope in my private practice for more than
7. 0:2420 years, and I've been training dentists how to incorporate the
8. 0:28surgical microscope in everyday clinical practice for more than a decade.
9. 0:33Today we are going to talk about changing paradigms in clinical endodontics and in
10. 0:37particular, two things that have changed a lot in the last five or 10 years.
11. 0:42Changes in access cavity design, and changes in the way
12. 0:45how we use rotary Ni-Ti files.
13. 0:47Let's start with changes in access cavity design.
14. 0:50When I completed my post-graduation in 2001, and started practicing.
15. 0:54We were told to do what we call straight line access, what we meant by straight
16. 0:59line accesses; by the time you finished your access, irrespective of however
17. 1:04small the exposure was, by the time you were done, we were expected to enlarge
18. 1:10the cavity in such a way that you have uninterrupted access and visualization
19. 1:16to all the canals in that tooth.
20. 1:18So something like this.
21. 1:19If it was a mandibular molar and it had, let's say, three canals, and by
22. 1:23the time you finished your access cavity and started instrumenting these teeth.
23. 1:27This was the view we were expected to have.
24. 1:29You had uninterrupted access and visualization to all
25. 1:33the three canals like this.
26. 1:35Compared to what we do now is if you look at the same tooth and by the time
27. 1:39we finish the access cavity, we don't have what we call straight line access.
28. 1:43We have something known as orifice directed access where you
29. 1:46can't really see all the canals at the same time in one view.
30. 1:50This is what we call orifice directed access.
31. 1:53If conditions are good and the under underlying pulpal anatomy allows
32. 1:56it, you can make your access even smaller, like what you see here.
33. 2:00This is a mandibular second molar, and the nature of the pulp chamber and the canals
34. 2:05underneath the access is such that you can get away with an even smaller access.
35. 2:10Now before we get into specifics, we have to understand why is it that we were doing
36. 2:15straight line access in the first place?
37. 2:17Why is it that we were taught to do straight line access?
38. 2:19There are two reasons for this.
39. 2:21First of all, we wanted to have uninterrupted visualization because we
40. 2:26are talking about a time when there wasn't any sophisticated ways of Magnification.
41. 2:31We didn't have enough light.
42. 2:32So the only way by which you could visualize these multiple canals in
43. 2:35posterior teeth, or even anterior for that matter, is by widening these walls so
44. 2:39that you allow enough light to go in there so you can actually see what's in the
45. 2:43tooth rather than making tiny accesses.
46. 2:45Because if you did make a tiny access, you didn't have the technology
47. 2:49to see beyond these tiny access.
48. 2:51So that's the first reason.
49. 2:53The second reason is the instrumentation itself.
50. 2:55First of all, you need to see these canals to instrument these canals.
51. 2:58So even if you're using hand instruments, you needed enough light.
52. 3:02So that's the other reason why we made these accesses big.
53. 3:04And then once rotary Ni-Ti, files came into play, let's say in the late
54. 3:081990s, early two thousands, that's when these rotary Ni-Tis became popular.
55. 3:13And the earlier rotary Ni-Ti I files were rather bulky.
56. 3:16They were increased taperi.
57. 3:17And not as resistant to cyclic fatigue or torsional resistance
58. 3:21for that matter as newer files.
59. 3:23They tend to break easily if they had multiple interferences.
60. 3:26So one of the ways to use these efficiently without danger of breaking was
61. 3:30to remove all coronal interferences, which means you had to flare out the walls.
62. 3:34And flare out any coronal interferences before inserting
63. 3:37these files into these canals.
64. 3:39So we were told to do straight line access to facilitate the
65. 3:42use of these rotary files.
66. 3:44So when I started practice, and these are some of my radiographs from way
67. 3:48early, say about 21 years ago, and you can see even when the canals were very
68. 3:53small coronally, by the time we finished endo and the patient went out of my
69. 3:56clinic, this is how they used to go.
70. 3:57You had these huge greater taperied obturations, where the obturation
71. 4:02material was dense and the only focus was whether or not you got a dense
72. 4:05obturation material in the Canal There was hardly any emphasis given into how
73. 4:09much of Coronal structure was removed.
74. 4:11The minute that you discovered all these extra anatomy, people used to applaud
75. 4:15without really caring whether or not there was something left of the tooth
76. 4:18The emphasis was always as to how many canals you found, whether you filled
77. 4:21them well, whether or not you were able to negotiate a sharp curvature.
78. 4:25Nobody really asked whether.
79. 4:26There was anything left of the tooth coronally, so we never had
80. 4:29that in built in our protocols.
81. 4:31It was always about how well you treated the root canal anatomy.
82. 4:35There was not much importance given to what's there coronally.
83. 4:38Even treatment cases, when somebody sent a re-treatment case, the emphasis was
84. 4:41always on what did you do in the root?
85. 4:44Not what's left in the coronal part.
86. 4:45Nobody really cared that the patient, when they came to you before you
87. 4:49attempted re-treatment, there was a lot more coronal tooth structure remaining.
88. 4:52By the time the patient left your clinic.
89. 4:54There was a lot of coronal tooth structure removed.
90. 4:56So this part was not given a lot of importance back in the days and
91. 4:59when patients came back Four or five years down the road and there
92. 5:02were a lot more extractions because we were using these bulky rotary
93. 5:05Ni-Ti files and huge accesses,
94. 5:07nobody really correlated the fact that these fractures could
95. 5:11Probably be because we were removing a lot more tooth structure.
96. 5:13It took a long time for clinicians to accept this fact, and that's why
97. 5:17you see this whole trend of being a little more conservative these days.
98. 5:20Now, if you look at the language in endodontic literature, it
99. 5:23too has changed over the years.
100. 5:24Now this is from a friend of mine, Dr. Pushpak Narayana, based in the U.S.
101. 5:28He was quick to point out that if you look at the literature and some of the
102. 5:31statements, this is from 1899, you can see "the thorough opening of the pulp
103. 5:35chamber will often require the sacrifice of considerable tooth substance. But
104. 5:39this though a pity, is unavoidable".
105. 5:42So they did point out that, you know, it's such a pity that we have to remove
106. 5:45so much tooth structure, but we have to do it because we need to remove the pulp.
107. 5:48So at least they acknowledged it as early as 1899.
108. 5:51If you look at this statement from 1900, you can see: "the first step
109. 5:55is to get direct and free access to every canal of the tooth.
110. 5:58This may, at times appear to involve the removal of an undue
111. 6:01amount of crown of the tooth.
112. 6:02Unfortunately, this is true, but care is to be exercised that no more than
113. 6:06necessary of the walls, particularly the floor of the pulp chamber, is to be burred
114. 6:10away to avoid mechanically weakening the tooth." So they were quick to point
115. 6:15out that: look, we are doing this to clean out the pulp, but just remember,
116. 6:18try and conserve tooth as much as possible.
117. 6:21But somewhere later on, say from 1946, the language started to change.
118. 6:25This whole concept that we need to hang onto the tooth structure;
119. 6:29that started fading away and people started talking In this tone: "access
120. 6:33through root canals must be obtained along a straight line access".
121. 6:36So that became more important rather than conservation of tooth structure.
122. 6:39This is courtesy: Dr. Pushpak.
123. 6:42What are these changing paradigms in clinical Endodontics?
124. 6:44Well, the first paradigm and the most important one is: rather than just
125. 6:47rely on the classic endodontic triad, which involves cleaning and shaping
126. 6:51and Obturation, clinicians have pointed out that we need to give some
127. 6:54importance to dentine preservation.
128. 6:56And the way you preserve dentine is by incorporating tools like
129. 6:59microscope cone beam ct, and then use the information that you get from
130. 7:03these two things to use conservative instruments so that you can periform
131. 7:07more conservative instrumentation.
132. 7:08So remember, it's microscopes, Cone Beam CT and conservative instruments.
133. 7:13You remove any one of these, then it starts becoming less effective.
134. 7:16So why microscopes?
135. 7:17Because remember; if you're going to make these small access, then
136. 7:21you need some tool to provide you increased illumination, visibility.
137. 7:24Otherwise, you just can't see anything beyond these small access.
138. 7:27So microscopes very, very important.
139. 7:29Cone Beam CT because you need some information.
140. 7:31If you're going to make these tiny accesses, you can't do a lot of guesswork
141. 7:35to see how many canals are there.
142. 7:37So you would rather have that information in advance so that you can plan these
143. 7:40small accesses because you already know how many canals are there, rather than
144. 7:44guessing it after you make your access.
145. 7:46So Cone Beam CT equally important.
146. 7:48And then the third part of the puzzle, which is: heat treated instruments.
147. 7:52You know, back in the days when you use rotary Ni-Ti, they were flexible,
148. 7:55but they couldn't be prebent, so you couldn't get them around walls,
149. 7:59which were not straight enough.
150. 8:01But these days you have heat treated alloys so you can prebent
151. 8:03them and get them around curves.
152. 8:05So that's the big change that's happened.
153. 8:08So rather than relying on straight line access where you need uninterrupted access
154. 8:12for those older instruments, we can pre curve these instruments and get them into
155. 8:16what we call Orifice directed access.
156. 8:18So that's a big change.
157. 8:19So all the emphasis these days is how to preserve peri cervical dentine.
158. 8:24Now what do we mean by peri cervical dentine?
159. 8:27peri cervical dentine means this: which is about 4 mm of dentine above the
160. 8:31alveolar crest, and about 6 millimeters of dentine below the alveolar crest.
161. 8:35So the idea is that we want to preserve this, and the
162. 8:38literature is very clear on this.
163. 8:40The longevity of the tooth is directly proportional
164. 8:43to how much of coronal tooth structure remain.
165. 8:45How much of PCD or pericervical dentine remains in the tooth after
166. 8:51restorative and endodontic procedures.
167. 8:52So this 4, mm of tooth structure, pericervical dentine above the alveolar
168. 8:57crest and 4mm below the alveolar crest is what we need to preserve.
169. 9:01And one of the ways to preserve this is by doing something
170. 9:03called orifice directed access.
171. 9:06What is orifice Directed access?
172. 9:07Let's assume that, this is a tooth with a large distal cavity and you wanna make an
173. 9:12access cavity to access these orifices.
174. 9:14In the traditional way, We would move this wall all the way till here so
175. 9:18that you get uninterrupted straight line access like this so that you
176. 9:21can instrument the canal like this.
177. 9:23Instead of that, an orifice directed access is where you end your
178. 9:26access cavity here so that you can instrument this canal from here.
179. 9:31So we have orifice directed access here for the mesial canals, and you
180. 9:35have access to the distal canals.
181. 9:37And once you
182. 9:37have accesses into the orifice like this, there is
183. 9:41no real rationale to move this wall here.
184. 9:43So
185. 9:43this is what we call orifice directed access.
186. 9:46Now
187. 9:46when you compare that with a microscope, this is a
188. 9:48traditional straight line access.
189. 9:50You can have a look at this and you go straight into these canals
190. 9:53in in one angle, but with the microscope, because of the fact that
191. 9:57you have increased illumination and magnification, you can rotate the mirror.
192. 10:01So you look at this.
193. 10:03And you can see here, if you're using a mirror, you can't
194. 10:05really see all three canals.
195. 10:06But if you were to rotate the mirror, you decide which canal
196. 10:09you're looking at, and then all you need to do is rotate the mirror and
197. 10:12you visualize one canal at a time.
198. 10:14So what we do here in this particular case, for example, is we rotate the
199. 10:18mirror and that's your mesiolingual canal.
200. 10:21You rotate the mirror again, and you can see the mesio buccal canal.
201. 10:24And then if you want to see the distal canal, you rotate the
202. 10:26mirror again in another direction and you see the distal canal.
203. 10:29So
204. 10:29this is what we call orifice directed access, where
205. 10:32you can't really see all the orifices in one view, but depending on what you
206. 10:37wanna see, you can rotate your mirror and you can see one canal at a time.
207. 10:40If the underlying anatomy allows you to do so, then you can make
208. 10:43your accesses even smaller.
209. 10:45Like in this particular case, this is a mandibular second
210. 10:47molar, which had a large onlay.
211. 10:49So our goal is to preserve the onlay, and I'm able to do this with a very
212. 10:52small access because every time you rotate the mirror, you can see a
213. 10:55different part of the underlying canal.
214. 10:57So you can see here.
215. 10:59That's all the access you need to periform a very nice cleaning
216. 11:02and shaping and obturation.
217. 11:04So depending on what the underlying anatomy is and where the orifices
218. 11:07are, you can plan your accesses rather than having standardized
219. 11:12wide access cavity preparations.
220. 11:14This is another example.
221. 11:15This is a mandibular first molar.
222. 11:17With two cavities, distal and mesial.
223. 11:19In our traditional access cavity preparation, we would remove this
224. 11:23whole chunk and leaving behind only the buccal and the lingual walls.
225. 11:27But in the modern way of preparing is you would end up something like this.
226. 11:30We call it a truss, where you remove a little bit of the mesial and distal.
227. 11:34And this is more than enough to access these canals, and this is more than
228. 11:37enough to access the distal canals.
229. 11:39So once you've done that and you're achieving your
230. 11:41goals, then why remove this?
231. 11:43Because it doesn't help you in any way.
232. 11:44So why not leave this in place?
233. 11:47this is against the conventional access cavity preparation, and your final post
234. 11:51obturation would look something like this, where you leave this part behind.
235. 11:55Now, this is something that I do in my hands, which is not extremely skilled.
236. 12:00There are many more skilled clinicians, far more skilled than
237. 12:03me, and these people are able to do this even more conservatively.
238. 12:07An example would be Dr. Pushpak, who's a friend of mine based in Miami.
239. 12:12And if you look at his preparations, this is something that he does
240. 12:14consistently in virtually every case.
241. 12:16And you see here.
242. 12:17Very small access; stepped access.
243. 12:19just about enough to negotiate the underlying anatomy and preserve so
244. 12:23much of coronal tooth structure.
245. 12:25So this is something that a lot of talented clinicians do, and
246. 12:29I am not as skilled as these clinicians, but I try to do my best.
247. 12:32Just be aware that there are people who can really push the limits
248. 12:35and take it to a whole new level.
249. 12:37And there are many clinicians like this.
250. 12:39Pushpak is just one example.
251. 12:41Some of the key changes that's happened over the years is we got
252. 12:44used to skinnier preps like these.
253. 12:46Whether or not these are enough for cleaning and shaping is a topic for
254. 12:49another video altogether, but just be aware that these are the two main changes.
255. 12:53We are
256. 12:53doing what we call orifice directed accesses,
257. 12:56and the reason why we are able to get away with this is that we can prepare these
258. 13:00canals at an angle rather than straight line because of the fact that we have
259. 13:04better instruments which are heat treated.
260. 13:06So that's the big change.
261. 13:08If you look at it, this is a change in my own preparations.
262. 13:10If you look on the left is how my radiographs used
263. 13:13to look from 20 years ago.
264. 13:14Large accesses and huge tapered.
265. 13:17Compare that with how a patient works out these days.
266. 13:19Smaller accesses and smaller preps.
267. 13:21So that's the big change.
268. 13:23And when you look at a philosophy point of view, this is the change.
269. 13:27You want to have dentine preservation, and we have dentine preservation because of
270. 13:31these three elements, the microscope, cone beam, ct, and conservative instruments,
271. 13:36and all three need to go hand in hand.
272. 13:38Why microscope?
273. 13:38Because without microscope you don't have illumination.
274. 13:42You don't have magnification, so you can't really do anything.
275. 13:45Why CBCT?
276. 13:46Because you need to know what's the anatomy, because based on that
277. 13:48anatomy, you can make your accesses smaller rather than fumbling around.
278. 13:52And only then can you use conservative instruments to maximize.
279. 13:56Now, when clinicians like these do such amazing work and put it on the
280. 14:01internet, a lot of people get triggered.
281. 14:02And the reason they get triggered is that it isn't easy to do work like this.
282. 14:06It requires a considerable amount of skill and practice.
283. 14:09So when you don't have that skill and practice then naturally,
284. 14:12there is a tendency to attack
285. 14:14these clinicians who put up this work online.
286. 14:16I understand it's tough.
287. 14:17I myself am not capable of doing work like this, but it doesn't mean that
288. 14:21we bring down the people who do this, but understand the people who are
289. 14:24doing this are not blindly doing this.
290. 14:26The problem is that a lot of people look at these miniature accesses
291. 14:29and they start taking only a few elements from the triad, for example.
292. 14:34People don't have a microscope, they don't have cone beam CT.
293. 14:37They just buy conservative instruments and then start
294. 14:40doing what we call Ninja access.
295. 14:42This is not a good way to do this.
296. 14:43The good clinicians who are doing this at a very high level, they are doing it in
297. 14:47a certain way, and you have to replicate all the ways by which they are doing
298. 14:52it rather than just take some elements.
299. 14:54So it doesn't work if you just use heat treated instruments and make
300. 14:57small cavities or access cavities.
301. 14:59If you don't have microscope to visualize it, then you can't do a good job.
302. 15:02If you don't have cone beam CT, additional information, then
303. 15:05you can't do an effective job.
304. 15:06So everything goes hand in hand.
305. 15:09However, the idea is that at least if you know what you need,
306. 15:13then you can take the next step.
307. 15:14And as far as microscopes are concerned, and I've been harping
308. 15:18on this for ages, years together, I myself have been using it for 20 years.
309. 15:22It's not something new.
310. 15:23And I've been teaching dentists, I have tons of students, hundreds of
311. 15:27students whom I've trained, and they've been using it for about 10 years now.
312. 15:31And there are people ahead of me who've already been using it 20 years before
313. 15:36me, so it's not a new concept anymore.
314. 15:38People have been using it for 40 years in clinical practice, and the problem
315. 15:42is, it's just a lack of awareness.
316. 15:45If you start exploring, things are very different now compared to what
317. 15:48it used to be 20, 30 or 40 years back.
318. 15:50There are so many microscope models available.
319. 15:53Accessibility is not a problem.
320. 15:54The cost is not a problem.
321. 15:56Costs of microscope have decreased dramatically, and you have training.
322. 15:59My own microscope online course is an example.
323. 16:02You can have a look.
324. 16:04Look at how we've designed it.
325. 16:05We made it really simple For anyone, any general dentist, to understand how
326. 16:09to incorporate the surgical microscope in everyday clinical practice.
327. 16:12Have a look.
328. 16:13The link is in the description below.
329. 16:15At least try and explore the possibility of incorporating the surgical microscope
330. 16:19in your practice, and you will find that it's not such a big deal.
331. 16:23It's just a mind block.
332. 16:24So please do consider possibility of using a microscope in your own
333. 16:29general practice for.
334. 16:31performing clinical endodontics.
335. 16:32If you found this
336. 16:34video useful, then do check out some of my other videos on the channel.
337. 16:38Don't forget to share it with a friend who you think might find it
338. 16:40useful, and don't forget to click on that subscribe button so that you get
339. 16:44notified every time I upload a new video.
340. 16:46I'll see you next week with another video.
341. 16:48Thanks for watching.