Clinical Tips, Endodontic Preparation Techniques, General Updates

The Lower Second Molar. Tricky in So Many Ways.

2 Comments

This case was referred as the treating dentist was astute enough to recognise that while some lower second molars only have two canals, the majority will have at least three. Only one orifice was visible mesially. The mesial roots of lower second (and third) molars are often challenging to treat for a number of reasons. Access can be difficult, there is often a double curve in the mesio-distal and bucco-lingual plane, and often we see a single orifice with two canals. This was one of those cases where only a single orifice was visible mesially.

Before attempting to tackle this case we took a CBVT. The CBVT presented a finding indicative of a second canal in the mesial root. This is good information to have, as if we suspect there are two canals, we know where to remove dentine in an attempt to locate the canal. If we suspect only one canal after viewing the CBVT, we don’t need to be needlessly removing further dentine in the all-important pericervical area.

 

The clinical picture is of one mesial orifice, but the CBVT indicates two canals.

The clinical picture is of one mesial orifice, but the CBVT indicates two canals.

The CBVT also tells us where to look – buccal or lingual of the orifice. In my experience, the classic situation for these canals is for the main canal to be the mesiobuccal, with the mesiolingual canal coming off the main canal a few millimetres below the orifice. The orifice to the second canal can be quite small, and as it comes off the main canal at a sharp, almost 90 degree angle, we have to be careful to open the canal coronally with some hand files before attempting to place a rotary file in it.

After removing about 2mm of dentin lingually to the existing orifice, the second canal was located.

After removing about 2mm of dentin lingually to the existing orifice, the second canal was located.

The final root filling with composite closing the access.

The final root filling with composite closing the access.

So there you have it. One more little gem in your bag of tricks for treating difficult anatomy. Have you had experience in cases such as this? Share your comments below.

Pat

Endodontic LA

Faster, More Comfortable LA?

1 Comment

One of the most frustrating occurrences in endodontics is failure of LA. This can sometimes happen due to a technique failure, but there are also patients for whom LA is just not very effective. Difficulty in anaesthetising certain patients has been identified for as long as there is history in medicine and dentistry.

Probably the most common issue that we come across though is failure of anaesthesia when working with inflamed pulps. In these cases most of us will take any help we can get. One method of potentially improving our LA success is buffering of LA solution prior to injection. This process may reduce the pain felt on injection, reduce post-injection tissue injury and reduce the time to onset of LA.

There are a couple of theories behind buffering that may explain these effects. As you know, LA is an acidic solution, with those containing vasopressors being more acidic. Increasing the pH of the solution prior to injection allows more of the LA molecules to be in the lipid soluble de-ionised form (as opposed to the positive ionised form). This is the form that is capable of diffusing into the nerve, resulting in anaesthesia.

Another theory is that sodium bicarbonate mixed with LA interacts with hydrochloric acid to create water and carbon dioxide. The carbon dioxide may assert an independent anaesthetic effect, as well as potentiating the effect of the LA itself.

Stanley Malamed, one of the best-known names in dental LA reports on a small cross-over trial using buffered LA with adrenaline (epinephrine) with a mean reduction in LA onset from 7 minutes 29 seconds to 1 minute 51 seconds. Read the full article by Malamed here. Anecdotal evidence from practitioners who buffer their LA support this rapid onset effect.

So, how can we all get access to this. One options is to buy the Onpharma buffering pen, which I understand is a great product and easy to use, but expensive. The other option is to purchase 8.4% sodium bicarbonate and mix the solution chairside. Here’s a video from our friends at youtube on how to do this:

httpv://www.youtube.com/watch?v=rJMD09iE_N4

If you’ve been using the Onpharma pen, or have comments or opinions on buffering LA, please comment below and share the knowledge.

You can also read my post on LA complications here.

 

Cracks in Teeth

Is it Really a Vertical Root Fracture?

Leave a comment

OK, we’re going to get a bit technical here and explain the difference between the commonly confused vertical root fracture and cracked tooth. Dentists like to be specific, and an accurate diagnosis will assist in determining appropriate treatment.

The reference for this is the American Association of Endodontics publication, “Cracking the Cracked Tooth Code: Detection and Treatment of Various Longitudinal Tooth Fractures”

A tooth with a crack that starts in the crown of the tooth and extends towards the apex is considered to be a cracked tooth. Further progression of the crack to the apex, resulting in separation of the crack is defined as a split tooth.

Endospot cracked tooth

The Cracked Tooth on the left, progressing to Split Tooth on the right. We see this in virgin teeth, restored teeth and endodontically treated teeth.

When we discuss a vertical root fracture, VRF, we are talking about a crack that starts in the root of the tooth. It doesn’t have to start at the apex. Mostly, VRF are associated with previously root filled teeth.

Vertical Root Fracture

The Vertical Root Fracture – a different presentation to the Cracked Tooth. This is more common in endodontically treated teeth than in teeth that have had no endodontic treatment.

So there you have it. No more incorrect diagnoses. Go here for more on how to diagnose cracked teeth.

Clinical Tips, Endodontic Surgery

The Compromise. Pre-Implant Apical Surgery.

Leave a comment

 

When it comes to compromised teeth, our goal may be to simply maintain a tooth for as long as possible. It also makes sense to plan for the future, so whenever I treat a tooth endodontically, I attempt to have all the possible outcomes in mind, including the eventual failure of the tooth.

This was such a case. The patient presented with a buccal sinus tract adjacent to the 11 (right central incisor). The 11 had been previously root treated. The tooth was mobile, but there were no periodontal pockets. To complicate matters an implant was present in the 12 position. The obvious treatment options were extraction, endodontic re-treatment and apical surgery.

Apicectomy

A large area of bone loss adjacent to an Implant. Careful planning is required.

I suspected that endodontic re-treatment was not going to be successful in resolving the infection. Re-treatment would also have the downside of further weakening the root as well as added expense and treatment time. The initial root treatment was done to a high standard by a dentist I know performs high quality work. I judged the likelihood of this being an endodontic treatment failure as low.

Extracting the tooth with such a large area of apical periodontitis and perforated buccal plate of bone also carries risks. I was concerned that extraction would allow a significant amount of soft tissue in-growth, compromising the amount of bone available for future implant placement. There is also the added aesthetic risk of loss of supporting tissues for the mesial aspect of the 12 implant. An augmentation procedure could be performed at the time of extraction, but given the acute infection, I would be concerned about the possibility of infection of the grafting material.

The left image shows removal of the pathological tissue. On the right, an apical crack can be seen.

The left image shows removal of the pathological tissue. On the right, an apical crack can be seen.

Ultimately, the patient elected to have apical surgery performed. A buccal flap was raised, sparing the papilla and the lesion curetted. The root was apicectomised. Upon inspection of the root under microscope, an apical fracture could be seen. This helps explain why no healing occured after initial endodontic treatment. I resected a few more millimetres to a level where no fracture was apparent. Staining with methylene blue showed a lateral canal. A retrofill with MTA was performed.

Further resection allowed removal of the crack. A lateral canal was seen and staining with methylene blue showed confirmed this. I knew there was a lateral canal at that level as during the initial removal of GP with ultrasonic, the GP could be seen expressing through the lateral canal. The image on the right is of the MTA retrofill.

Further resection allowed removal of the crack. A lateral canal was seen and staining with methylene blue confirmed this. I knew there was a lateral canal at that level as during the initial removal of GP with ultrasonic, the GP could be seen expressing through the lateral canal. The image on the right is of the MTA retrofill.

I have no doubt that simply suturing the flap in place in this case would still result in significant soft tissue fill of the defect left by removal of the apical pathology. Ultimately, our goal now was to regenerate as much bone as possible. We are dealing with a five walled defect, and the placement of calcium sulfate in the defect will help prevent soft tissue invasion, as well as allow replacement with native bone. I also wanted to avoid having to place either a rigid membrane (with later removal required) or having to pin a collagen membrane in place.

On the left the extend of the lesion can be seen with implant threads exposed. These were debrided and scrubbed. Calcium Sulfate was then used to fill the defect. Note the complete deshiscence.

On the left the extent of the lesion can be seen with implant threads exposed. These were debrided and scrubbed. Calcium Sulfate was then used to fill the defect. Note the complete deshiscence of bone over the central incisor.

The tooth was taken out of occlusion. It was lacking bony support prior to surgery and has even less post-surgery. Hopefully healing of the bone will facilitate further support of the tooth. It is possible that this tooth will fail, but it is also possible that the tooth could remain functional for a number of years. Ultimately, we have treated with an end-point in mind and given the complicated presenting situation, a compromise is the best that could be achieved at this stage.

The flap was closed tih 6/0 sutures. A sling suture was used to keep the flap coronally positioned. The Xray shows the MTA fill, as well as the limited periodontal support.

The flap was closed with 6/0 sutures. A sling suture was used to keep the flap coronally positioned. The Xray shows the MTA fill, as well as the limited periodontal support.

The tooth was relieved from occlusion.

The tooth was relieved from occlusion.

Would you have managed this differently? If so, please comment below.

General Updates

Cases of Note: Silver Point Removal

Leave a comment

The anterior abutment of this bridge was symptomatic. The patient was keen to retain the bridge if possible. A decision was made to attempt re-treatment thorough the bridge.

Three silver points were visible after removal of the core material.

Three silver points were visible after removal of the core material.

One of the keys to removing silver points is to carefully dissect the core material around the point so that the end of the point can be grasped with Steiglitz forceps.

The silver points were grasped with Steiglitz forceps and removed.

The silver points were grasped with Steiglitz forceps and removed.

The tooth was dressed with calcium hydroxide for two weeks, symptoms resolved and obturation completed with GP and AH Plus. Two fibre posts were placed with a luxacore core. The porcelain was etched and silanated, and opaque porcelain was used to help mask the darkness of the metal base and the access restored with composite. Some of the porcelain had fractured away during access and this was restored with composite as well.

Obturation with two fibre posts and a luxacore core.

Obturation with two fibre posts and a luxacore core.

 

Post-obturation radiographs.

Post-obturation radiographs.

Would you have managed this differently? If so, make a comment below.

General Updates

Longer Lasting Endo. Is Smaller Stronger?

8 Comments

Recently there has been a push towards patient-centred outcomes in dentistry. This means we should treat towards outcomes that are important to the patient. Most patients want teeth that are aesthetic and free of disease and pain, and they want the teeth to be there forever.

In recent years, there has also been a push towards conservation of dentine during endodontic procedures in order to maintain as much strength in the tooth as possible. A recent study by Krishan et al showed that the concept of “straight line access”  may lead to significant decreases in fracture resistance in premolar and molar teeth. Although this is a bench-top study, and a long way from a definitive link to outcome, to me it makes sense that if we are going to give the patient the longest lasting solution, then giving them the strongest tooth possible should be one of our primary goals.

In this case, a 22 year old patient was referred for endodontic treatment of the lower left second molar as an odontogenic cyst was to be removed and this would have resulted in loss of vitality of the tooth. There had also been some resorption of the mesial roots. Careful planning of the access allowed all canals to be treated without unnecessary removal of of “pericervical” dentine, the tooth structure that Clark and Khademi feel is the most important to be conserved. The pulp chamber was filled with amalgam and the access closed with composite resin.

I would warn that this approach is more clinically challenging to do well, and that when attempting to be conservative, that the procedure should be titrated. That is, if you need to prepare a canal, and your access isn’t allowing you to do this, then obviously, you need to remove further tooth structure in order to complete the endodontics.

Endodontic access allows good vision and file access whilst conserving tooth structure.

Endodontic access allows good vision and file access whilst conserving tooth structure.

Pulp chamber filled with amalgam and the access closed with composite resin.

Pulp chamber filled with amalgam and the access closed with composite resin.

References:

Krishan R, Paque F, Ossareh A, Kishen A, Dao T, Friedman S. Impacts of Conservative Endodontic Cavity on Root Canal Instrumentation Efficacy and Resistance to Fracture Assessed in Incisors, Premolars, and Molars. JOE In Press.

Clark D, Khademi J. Modern molar endodontic access and directed dentin conservation. Dent Clin North Am 2010;54:249–73.

 

Diagnosis of Pulpal Pathology, General Updates

Overdiagnosis in Endo? Surely not!

1 Comment

I’ve noticed that the issue of overdiagnosis is really getting a lot of attention in the medical world. Overdiagnosis occurs when a person is diagnosed with a disease, but that disease, if left untreated would never have caused symptoms or death. This results in treatment being provided to people when they could have been left alone and never would have suffered. It is especially problematic when testing is involved that returns abnormalities that can be interpreted to indicate disease, but the test is inaccurate. It is also especially problematic when the treatment has significant consequences or side effects.

There was a conference held on the topic last year in the UK and I see this year’s conference is sold out. httpv://www.preventingoverdiagnosis.net/

I must admit that after reading a bit on the topic, there are a lot of aspects of overdiagnosis that apply to dentistry, as we are so focused on prevention of disease, and we do a lot of tests (pulp testing, bitewing and PA radiographs, probing of fissures) that can return both false positives and false negatives. Also, our treatments are invasive, costly and often irreversible.

This youtube video gives an easy to understand overview of testing: https://www.youtube.com/watch?v=U4_3fditnWg.

What are people’s thoughts on this? Do you think we are guilty?

Clinical Tips, Cracks in Teeth, Endodontic Radiography

Now you see it, now you don’t

3 Comments

Sometimes in endodontics, we miss signs, symptoms or findings that are important to diagnosis or prognosis. Sometimes our brain fools us into thinking we see or find things that aren’t really present. This case is a good example of both of these possible errors. The patient presented complaining of mild tenderness to bite on the 26. The tooth was slightly tender to percussion, mobility was normal and there was slight tenderness to palpation on the palatal aspect. Periodontal probing was within normal limits. Here are the intra-oral radiographs:

Bitewing cracked tooth

PA - Cracked toothCracked tooth PA

I decided to take a CBVT scan. The main finding on the scan was a lucency at the mesiopalatal aspect of the marginal tissues.

CBVT_Crack1

CBVT_Crack3

CBVT_Crack2

My plan was now to raise a flap to investigate. Once LA had been applied I probed again. This time I found a narrow deep pocket at the mesiopalatal aspect of the tooth. The locating of a pocket after giving LA that had not been found prior to LA is something that happens in my practice on an occasional, but recurring basis. In fact, it’s been happening since one of my demonstrators made me look silly during my endo specialty program by finding a pocket that I said was never there. I think there are a couple of factors behind this:

1. We are happy to probe more firmly when the patient is numb;

2. Radiographic findings, especially on CBVT point you to a specific location to probe for a pocket.

In a case such as this, the symptoms, followed by the radiographic finding increases the probability of a fracture being present. The added finding of a deep, narrow pocket increases the probability even more. That said, the fracture is not confirmed until visualised. So, a flap was raised and the root surface stained with methylene blue. The visualised crack confirmed the diagnosis.

page7

The CBVT helped immensely in this case. However, it’s easy to look at the CBVT and think, “Ah, I see the crack!” (go back to the bottom CBVT image above and look again),  but also have a look around the rest of the teeth shown in the CBVT. Almost all of them seem to have lucent lines running through them that look like”cracks”. It is very dangerous to look at the lucent line on a CBVT and “diagnose” a crack. All we have in this case from the CBVT is a finding that may be typical of a pattern of bone loss associated with a crack. It added to the other findings to lead to the final confirmation of the diagnosis of cracked tooth via visual inspection.

Let me know your thoughts on this in the comments section below.

Pat Caldwell

Aetiology of Apical Periodontitis, Endodontic Surgery

Sometimes, The Simplest Option is the Best Option

1 Comment

When we are dealing with apical pathology, we should always have in our mind that intra-canal infection is by far the most common cause of disease. In a case such as the one shown below, no canal can be seen radiographically, and no canal was found by the dentist that accessed the tooth. But we should remember that a pulp that has undergone pulp canal obliteration will still in most cases have either vital or infected tissue contained within it at a microscopic level.

This tooth underwent apicectomy twenty years ago after an unsuccessful attempt to locate a canal. The tooth remained asymptomatic until symptoms of an abscess occurred.

This tooth underwent apicectomy twenty years ago after an unsuccessful attempt to locate a canal. The tooth remained asymptomatic until symptoms of an abscess occurred.

The patient above presented to me for treatment of acute apical abscess. The central incisor had been accessed twenty years earlier, but no canal could be found (despite the large access). At that stage an apicectomy was performed with an amalgam retrofilling placed. The tooth remained asymptomatic for twenty years prior to the abscess forming.

Consider the options we have available:

1. Endodontic treatment, with or without apicectomy;

2. Re-apicectomy;

3. Extraction and bridge/implant.

The previous apicectomy, pulp canal obliteration and large access make this tooth appear to be a difficult to manage case, and this could be mistaken for it having a poor prognosis. But we have to be careful not to over-think the case. With a microscope available, endodontists expect to be able to prepare canals in most teeth such as the one shown above, and therefore take care of the intra-canal infection.

One option would be to take a CBCT to further assess the presence of a canal. In this case however, there has already been an access made, and we are assuming the canal is infected and necrotic, so the decision was made to remove the restoration to see if any canal could be located. The canal was located, prepared and dressed with calcium hydroxide. No exudate was produced, and there was a definite stop at the level of the amalgam retrofilling, The symptoms resolved and four weeks later the canal was filled. The patient was advised that an apicectomy may be required if symptoms recurred. The presence of the amalgam apically, is not by itself sufficient not make apicectomy an obvious option.

Two year review revealed the tooth remained asymptomatic, and healing of the apical pathology had occured. This was despite the amalgam retrofill remaining.

Two year recall. The tooth is asymptomatic and resolution of there is no longer an apical finding present radiographically.

Two year recall. The tooth is asymptomatic and there is no longer an apical finding present radiographically.

The main point to take out of this is that treatment of intracanal infection should be our first priority. Secondly, when we manage to get rid of intracanal infection, then the material used to fill the canal isn’t so important, as long as we maintain a good coronal seal to prevent reinfection. Thirdly, when you see a calcified canal such as this one, it may be a good idea to refer to someone who has experience in these types of cases if this is an option, as the location of the remnant of the canal can be challenging.

Pat Caldwell