The Compromise. Pre-Implant Apical Surgery.

September 6, 2014 Pat Caldwell 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.

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.

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.

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

Sometimes, The Simplest Option is the Best Option

January 12, 2014 Pat Caldwell 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.

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

Endodontic Re-treatment, Endodontic Surgery

Apicoectomy Failed? Maybe It’s Worth Trying Again.

March 8, 2011 Pat Caldwell Leave a comment

Endodontic Microsurgery - You Need it!

In a study published recently in the Journal of Endodontics, cases of failed endodontic surgery/apicoectomy were treated with re-surgery (Song et al. 2011). A 12 month follow up with a 77.8% recall rate showed success (defined as healed or healing) in 92.9% of the cases treated. By far, the most common likely causes of failure were a poorly placed root end filling or a lack of root end filling.

This study nicely demonstrated two things. Firstly, endodontic surgery performed under the operating microscope and using microsurgical techniques including ultrasonic retropreparation and biocompatible filling materials such as MTA or Super EBA has a high success rate. The other thing it shows is that endodontic surgery done poorly doesn’t work particularly well. I’ve previously shown a case where an apicoectomy had been performed with no retrofilling placed and no consideration for the biological cause of disease. It was doomed to failure the moment it was even considered.

Success rates for modern endodontic surgery are around the 90% mark (Tsesis et al. 2009). This is a massive improvement on the expected outcome for surgery using traditional means such as micro handpieces and amalgam for retrofilling. In another recent study it was found that, at least in America, endodontic surgery was the least expensive intervention for failed RCT when compared to endodontic re-treatment and crown, extraction and fixed partial denture, or extraction and implant (Kim & Solomon, 2011).

I’m all for implants in the appropriate situation, but they are expensive and treatment can extend over a number of months and quite a few visits. The same can be said for endodontic re-treatment. I guess the message here is that endodontic surgery performed by a competent Endodontist should be considered a first line treatment option when dealing with persistent endodontic disease.

References:

Kim S, Solomon C. Cost-effectiveness of Endodontic Molar Retreatment Compared with Fixed Partial Dentures and Single-tooth Implant Alternatives. J Endod 2011;37:321–325.

Song M, Shin S, Kim E. Outcomes of Endodontic Micro-resurgery: A Prospective Clinical Study. J Endod 2011; 37:316–320

Tsesis I, Faivishevsky V, Kfir A, Rosen E. Outcome of surgical endodontic treatment performed by a modern technique: a meta-analysis of literature. J Endod 2009; 35: 1505–11.

Aetiology of Apical Periodontitis, Endodontic Surgery

Choosing your battles – Apicoectomy

August 9, 2010 Pat Caldwell 1 Comment

I had a patient present to me this week complaining of pain and swelling associated with a lower molar. She had previously had root canal therapy and then apicoectomy performed by her dentist about 8 months ago. She was disappointed that symptoms had recurred as she had seen the dentist in her home country one month ago and he had told her the treatment had been successful, healing was proceeding well and that a crown could be placed. She told me that her dentist had told her prior to the surgery that she had a large lesion and that the actual surgical procedure had been very painful.

Tenderness to percussion or palpation, pain or fistula formation may indicate failure of an apicectomy.

This case is a good one to base a discussion on case selection for apicoectomy. The first thing to note is that the quality of the original RCT is inadequate. One mesial canal is filled well short of the appropriate length. Additionally, the distal canal is poorly filled. There is also evidence that the composite resin restoration may be leaking. It’s reasonable to assume that the root canal was failing due to infection within the canals, and it has been clearly shown that this is the case for the vast majority of root canal treatment failures.

So from a purely endodontic point of view (disregarding alternative options or the influence of prosthetic factors), we have two main options. First, we treat the infection in the canal by undertaking RCT re-treatment. Secondly, we “entomb” the microorganisms in the canal and prevent them and their products reaching the periapical area by undertaking periapical surgery with retrofill.

In this case, we can see that periapical surgery has been undertaken, but no retrofill has been placed. Given the (very safe) assumption that infection remains within the canal, then simply resecting the apical portion of the root will not achieve anything of use. The canal will remain open and the microorganisms will continue to thrive within the canal continue to release products that induce an immune response in the periapical tissues. Unfortunately for this patient, their dentist has shown a lack of understanding of the cause of periapical pathology and needlessly put the patient through a surgical procedure. There may have been some healing of the lesion sue to the surgical procedure, but complete healing could not be expected.

A recent randomized clinical trial compared the outcome of apical surgery where either an MTA retrofilling was placed or the GP filling of the resected root was smoothed and no retrofill placed (Christiansen et al. 2009). The outcome was quite clear that placement of MTA retrofill provides a superior rate of healing compared to just leaving the GP intact. The study didn’t really go into detail as to the quality of the orthograde root fillings in the teeth, but in a situations such as the case discussed above, a retrofill is a necessary part of the procedure. For those of you who don’t have experience with preparing and placing retro fills, it is a skill that requires some practice and specialised equipment. This is especially so once you start to treat molars and teeth with isthmuses.

Without seeing the initial radiographs, I’d have to say that from a purely endodontic point of view, RCT re-treatment should have been considered prior to any surgery. This may have been successful in treating the infection alone, but if not, it provides a better chance of the canals being cleared of infection prior to the surgical procedure, and this then improves the chances of success of the subsequent surgery. Alternatively, apical surgery with retrofill performed by a skilled clinician might have been successful in this case.

Reference:

Christiansen R, Kirkevang L-L, Hørsted-Bindslev P, Wenzel A. Randomized clinical trial of root-end resection followed by root-end filling with mineral trioxide aggregate or smoothing of the orthograde gutta-percha root filling – 1-year follow-up. Int Endod J, 42, 105–114, 2009.

Clinical Tips, Endodontic Surgery, Study Guides

How to Manage Persistant Endodontic Disease Without Apical Surgery (Now With Three Year Follow-up)

March 6, 2010 Pat Caldwell 7 Comments

Despite Endodontic Re-Treatment The Second Molar Was Associated with a Sinus Tract. Resorption of the Distal Root Apex Can be Seen.

Intentional Reimplantation involves carefully extracting a tooth, performing root end resection and retro fill, and reimplanting the tooth. It is a simple and reliable procedure which can be performed by any dentist and can be used to retain teeth that might otherwise be deemed hopeless. See the Endospot Study Guide to Intentional Reimplantation at the end of this post for references and a full list of indications/contraindications etc.

In situations where endodontic procedures have failed or cannot be undertaken, endodontic surgery is a commonly used treatment modality. There are, however, situations where traditional endodontic surgery is difficult, or inappropriate. In particular, this occurs where anatomy such as a thick bony plate limits access (especially in the lower 2nd/3rd pre-molar), or vital structures such as neurovascular bundles are at risk (especially the mental n. in the region of the lower 1st/2nd molar). This also occurs due to other factors such as accessibility, lack of patient cooperation or a preference not to undertake surgical procedures.

In these cases, intentional reimplantation (IR) may provide an option to treat persistent apical disease. In certain cases, IR is the preferred option over surgery. IR is not a last hope procedure. When done according to protocol it is very predictable. The procedure itself is something that many dentists may find confronting, but in reality it is not difficult to do, and most dentists can have it in their repertoire.

I’ve mentioned that IR is not a last hope procedure, but in any event, when you have run out of options, and a tooth is to be extracted, then it may be worth considering treating and replanting the tooth.

The two main contraindications to IR are flared or curved roots and periodontal involvement. The first is an obvious contraindication, because the tooth needs to be able to be extracted in a controlled manner. One key factor for success is to limit the damage to the cementum layer of the toot. If the cementum layer or PDL is damaged, then there is a greater potential for resorption to occur. The second is obvious as well, because an unhealthy periodontium will complicate the healing process. Once again, see the study for a full list.

When I discuss this procedure with dentists, they are often concerned about the potential for resorptive processes and ankylosis. Most of this concern comes from experience with teeth that have been avulsed. IR is a completely different situation to a traumatic avulsion. You could reasonably expect far more trauma to the cementum and bone during a traumatic avulsion, but probably more importantly is that the tooth is often left , contaminated, dry and out of the socket for an extended period. This leads to necrosis of the PDL, and ankylosis ensues. With IR, the tooth is very carefully extracted and maintained out of the mouth in a moist environment for a very limited time. These conditions are ideal to allow healing.

A classic case is the lower second molar which has been treated endodontically and shows signs of persistent disease. In the case below, the patient was referred for management of persistent disease in the first molar. The lower right second molar has been re-treated by and endodontist 3 months prior to the patient being referred to me. Unfortunately, there was a sinus tract present, associated with the distal root of the 2nd molar (determined by taking a radiograph with a #30 GP point in the tract).

#30 GP Point Inserted into The Sinus Tract Traces to the Distal Root

I spoke to the treating endodontist who told me that the distal root had an open apex, and he had filled the distal canal with MTA. In this case, access and a large amount of bone overlying the root of the 2nd molar make surgery untenable. Even many experienced endodontists will tell you they have never performed traditional apical surgery on a lower second molar. After discussion with the patient, we decided to perform a reimplantation.

The tooth was periodontally sound, and exhibited normal mobility. It was not tender to percussion or palpation. Radiographic examination revealed a lucency associated with both roots, lucency in the furcation region and extruded material associated with both roots. Prior to extraction, the tooth is taken out of occlusion. When the tooth is repositioned, swelling may result in the tooth slightly extruding from the socket, so it is important to ensure there is good clearance from opposing teeth. Pre- & post-operative broad spectrum antibiotics such as amoxycillin are given. Chlorhexidine mouthrinse three times daily is initiated one day prior to the procedure and continued for one week after.

LA is given and the tooth carefully extracted. By this I mean that very gentle force is utilised. The tooth is grasped with forceps only by the crown. The root surface is not touched, so as to avoid damaging the cementum layer. It is common to spend 15 or 20 minutes extracting a tooth that might otherwise be extracted very rapidly. Obviously, the use of luxators and elevators is avoided.

Once extracted, I place a rubber band around the handles of the forceps to prevent the tooth being dropped. It’s important to keep the PDL moist, so have plenty of solution available and keep your assistant active in syringing solution over the PDL. A physiological solution is used. There is evidence that solutions such as hartman’s solution provide better stability of the PDL cells, but saline can also be used (a solution used in the transport of organs for transplant has been shown to by the best at maintaining viability of PDL cells, but this may be impractical).

The apicectomy is then performed using a high speed bur with copious water coolant. I know that water is not the best thing to be applying to PDL, but I think it’s more important to have coolant that to allow uncontrolled heat to be applied to the root. In general aim to remove 3mm of root tip. This should remove most of the accessory canals that may be harbouring microorganisms.

The next step is to use a small round bur to complete the retropreparation. There is no trick to this. Simply create a preparation in the root canal space 3-4mm deep. Any isthmus which is present between canals should also be prepared. This will especially occur in the mesial root of the lower molar. This preparation is designed to remove any infected GP and dentine and allow a retrofill to be placed which will seal in any remaining microorganisms or their products. Inspect the root surface for lateral canals and fill these in the same manner. In this case, the distal canal had been filled with MTA. MTA seals extremely well (compared to GP, which does allow micororganisms to pass) so there was no need to place a retrofill in the distal root.

The retropreparation has been completed in the mesial root. The distal root is filled with MTA so no retrofill is required.

There are many suitable materials for retro filling. The two most popular with endodontists are MTA and Super EBA. These materials have shown a good ability to seal and MTA in particular is highly biocompatible. MTA can be diifcult to handle, so make sure you have practised mixing and handling it first if you plan to use this. If these materials are not available, then IRM may be used. In the past amalgam has been used for retrofilling, but this material tends to corode over time, leading to loss of seal. When placing the retro fill, pack the material into the cavity with a small amalgam plugger, and then burnish.

The next step is to carefully debride the pathological tissue from the tooth socket. Here, it is important to try to avoid disturbing the PDL. By debriding, you are also removing the blood clot which may have formed in the socket. Irrigate the socket thoroughly and reposition the tooth with gentle pressure. It helps to have the patient bite gently on a wooden spatula to help ensure the tooth is correctly positioned into the socket.

Generally, no splinting will be required and a suture is placed over the tooth to hold it in position. Splinting is not desired as it impedes cleaning the area, and may lead to higher rates of resorption. If the tooth is excessively mobile after replantation, then consider splinting for a short period (3-4 days). Again, I’m aware that guidelines for traumatically avulsed teeth advise splinting, but a replanted lower molar has much greater primary stability than a replanted central or lateral incisor which was knocked from the mouth, and years of experience by endodontists conducting this procedure show that splinting is rarely required.

A radiograph is taken immediately after replantation to help confirm that the tooth is repositioned and as a baseline for healing. The sutures can be removed after 3 days and occlusion checked again. At this point some physiological movement due to occlusion is fine, but make sure the tooth is not high in occlusion. Most patients report very little discomfort after the procedure. Oral hygiene is important and flossing and brushing should resume as soon as the patient is comfortable.

The post-operative radiograph revealed I had failed to remove the extruded sealer which was associated with the mesial root. This was probably a result of careful debridement of the socket. The decision was made to leave this in place as re-extracting the tooth was likely to case more damage than benefit.

Review of the case mentioned above at 2 weeks revealed the tooth to be quite mobile. This is not unusual, as is not a cause for concern as the tooth will generally become less mobile. Importantly, periodontal examination was within normal limits. indicating that reattachment of the PDL had been successful. The sinus tract had healed. Examination at three months revealed no sinus tract, nil tenderness to percussion nor palpation, normal periodontal examination and normal mobility. Radiographic examination revealed excellent healing of the periapical areas. There continued to be lucency in the furcation area. This tooth will be monitored and I’ll update the post accordingly.

Pre-op and 3 Month Review Radiographs. Excellent, But Incomplete Healing of the PA Lesions are Apparent. Prognosis is Excellent. The First Molar Has Been Re-treated and Initial Healing of The PA Lesions is Also Apparent.

Six Month Review of Intentional Reimplantation

Six month review shows osseous healing adjacent to the root ends of the second molar. The tooth is functional, periodontally sound and mobility is normal. Coronal restoration should now proceed. The lesion on the mesial root of the first molar has also continued to heal but a lucency remains around the extruded sealer.

Update on this patient:

A three year review has now been undertaken. The tooth is asymptomatic, periodontal probing and mobility is normal. At this stage there appears to be no sign of ankylosis. The PA shows excellent resolution of the apical lucencies.

Occlusal view of restored first and second molar.

Side view. The tooth is healthy with no sign of return of the sinus tract and in function.

The three year review PA shows good healing of the apical lucencies. This simple and inexpensive treatment has allowed this patient to keep their tooth in function in the short term. I will keep recalling the patient.

The three year review PA shows good healing of the apical lucency. The lucency associated with the mesial root of the first molar has also resolved. This simple and inexpensive treatment has allowed this patient to keep their tooth in function in the short term. I will keep recalling the patient.

Lets Hear Your Thoughts:

I’d like to hear from others on your technique and experiences with IR. Feel free to send through cases and I’ll add them to this post.

References

Bender IB, Rossman LE (1993). Intentional replantation of endodontically treated teeth. Oral Surgery, Oral Medicine, Oral Pathology 76(5):623-630

Peer M (2004) Intentional replantation – A last resort treatment or a conventional treatment procedure? Nine case reports. Dental Traumatology 20:48-55

The EndoSpot Study Guide on Intentional Reimplantation:

The best known reference for IR is Bender IB, Rossman LE (1993). Intentional replantation of endodontically treated teeth. Oral Surgery, Oral Medicine, Oral Pathology 76(5):623-630. In a retrospective case series they followed 31 cases for 1 day to 22 years and reported an overall success rate of 80%.

Another good overview is provided by Peer, however this is a simple case series. Criteria for success/failure is not listed and no rates of success are given: Peer M (2004) Intentional replantation – A last resort treatment or a conventional treatment procedure? Nine case reports. Dental Traumatology 20:48-55

Primary Indications for IR are listed as:

Teeth have been treated unsuccessfully by conventional means (surgical/non-surgical)
Separated instruments cannot be bypassed or removed
Post/crown restoration requires retreatment
Apical surgery would remove enough bone to cause a periodontal pocket
Apical surgery would result in nerve injury or perforation of the maxillary sinus

Secondary Indications:

To gain access to perforations on the mesial/distal or lingual root surface (esp inraradicularly)
To treat grossly overfilled conventional root fillings and teeth with blunderbuss apices
To enable inspection of a root for fracture
When the patient will not accept apical surgery
When the wrong tooth is extracted or accidental avulsion of a tooth during the removal of crown in a prosthetic procedure;
Cases involving a deciduous tooth to allow it to act as a space maintainer

Contraindications for IR are:

Presence of periodontal disease in which there is marked tooth mobility, furcation involvement or gingival inflammation
Flared or curved roots
Fractured Roots
Patients are taking bisphosphonates

Advantages:

Less invasive than apical surgery
Simpler, and less equipment required c.f. apical surgery
Improved access for inspection and resection/retropreparation
Less soft tissue scarring

Disadvantages:

Potential for root resorption
Reduced access to apical pathology

the endospot

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