Treatment Planning a Fractured Cuspid

A 43-year-old male in good health was referred to my office for examination of tooth #33 (mandibular left cuspid) . This virgin tooth had been involved in a trauma and was now symptomatic to chewing and thermal stimulus. The case had been referred to me for endodontic treatment, but several other questions needed to be answered before we could determine whether endodontic treatment was warranted.

Examination of the Tooth showed a horizontal fracture running along the buccal crown face. Placing buccal pressure on the cusp tip allow the fractured incisal portion to move and the crack opened slightly. 

The extent of Fractures of the anterior dentition are often related to the energy that is transferred to the tooth during trauma. Living a cold winter climate means that I see a lot of hockey related injuries (pucks and sticks) as well as slips and falls on ice due to loss of footing.

Fractures generally fall under two categories:

1.  Fractures in which the incisal edge is sheared off horizontally in a “clean break”.  Generally, this is from a puck, baseball, projectile hitting the object at high speed with limited mass. Forces (Kinetic energy KE= 1/2 MV(squared)) are concentrated and the tooth often (but not always) shears off cleanly near the site of impact. In those cases, the pulp may or may not be exposed by the broken part of the tooth. The cleanly fractured piece can often be rebonded to the tooth ( after endo, if necessary) and the integrity and aesthetics of the tooth is fully restored without the need for further treatment if there is no pulp exposure.

2. Compound fractures These fractures often occur with large mass objects or falls in with very large forces are applied to the tooth that results in compound fractures of the tooth/root. ( Cross checking by hockey stick, slip and fall on ice or off of a bike) The tooth essentially “shatters”. Most often the fracture line on the buccal aspect ( from which the forces are applied) causes oblique fractures that are either crestal or subcrestal on the palatal/lingual aspect. The ability to restore these teeth depends on the extent of the fracture in this area and whether it can be managed periodontally and restoratively.

Several questions need to be addressed as we treatment plan the case:

1. How deep is the fracture and have ALL the fractured portions of the tooth been removed to examine the extent of tooth loss?

2. Can the tooth be restored with a margin that is not too far subgingival that it results in a chronic postop periodontal problem? Is crown lengthening indicated if the fractured portion can not be rebonded? Would forced eruption ( to eventually expose a manageable lingual margin) be a better option that crown lengthening?  (This depends on the particular situation i.e./ root length, periodontal support, tooth position.)
3. Would extraction and replacement with an implant be a better option than trying to save the tooth?

I consulted with the Periodontist involved with the case and explained that we could NOT initiate Endodontic treatment until a comprehensive treatment plan was formulated and presented to the patient. The patient was eager to save the tooth but I believed that we needed to explain that we didn’t know enough about the fracture at the moment to determine whether this was feasible.

The cbCT image showed a very faint radiolucent line that seemed to suggest the extent of the fracture was limited to the area between the two arrows in the above cbCT slice. If so, the prognosis was much better. However, the fractured portion of the tooth would still need to be removed to confirm this prognosis.

In the cbCT, we also noted that the cuspid root length was atypically short and that there was literally no bone covering the buccal aspect of the root. Extraction of the tooth and attempted implant placement would be difficult and invariably result in the need for significant bone grafting to allow for proper placement of the implant inside bone. So, from the looks of the cbCT, the implant option was not practical.

I concluded that Endodontic treatment of this cuspid was not the issue.
The real concerns are:
1. Where is the lingual extent of the fracture?
2. Is the fracture compound in nature?
3. Can a manageable,  Periodontally healthy crown margin be obtained with some kind of Perio surgery or Ortho extrusion intervention?

I told the Periodontist that until these questions were answered, it made little sense to consider Endodontic treatment. I suggested a combined approach where the Periodontist would remove the fractured portion, determine restorability ( in consultation with the restoring dentist) and then send the patient to me once a  treatment plan and strategy had been confirmed. If suitable or possible, the fractured portion could be retained and rebonded after the Endo treatment had been completed. If they determined that the  fracture had rendered the tooth unrestorable, other strategies for replacement (bridge?) may have to be considered and endo would not be necessary.

Although patients are frequently referred to an Endodontist for “a procedure”, it is incumbent on Specialists and referring Dentists to recognize other problems and concerns and to make sure they are addressed in the overall treatment plan.

Cemental Tear

This patient was referred to me for examination and consultation regarding a mandibular anterior tooth that had been previously treated by the Referring Dentist.  The 49 year old gentleman had a history of trauma when young and discoloration of the crown. The tooth was otherwise virgin.
Although the Endodontic treatment appeared to be relatively good (aside from the overextension of the filling material) , a large radiolucent finding (encompassing the entire root in all directions  and up the mesial side) had resulted in high mobility and a persistent mucosal defect at the buccal apex.

Conventional  and cbCT imaging showed complete bone loss around the entire periphery of the root in 360 degrees and hopeless prognosis. PA imaging showed what appeared to be a sliver of radio-opaque material on the mesial side of the root.

I informed the Referring Dentist that in my opinion the problem was not primarily Endodontic in etiology and that the radiolucency suggested a diagnosis of cemental tear. This resulted in breakdown of Periodontal support from a Periodontal rather than Endodontic problem.

The tooth was subsequently extracted by the Referring Dentist. However, a post extraction radiograph revealed persistence of retained cementum, left behind after the extraction.

At this point we consulted a Periodontist  as to whether the site could be used for placement of an implant and how to best manage any subsequent surgical procedures necessary. Would it  be feasible to graft the area sufficiently to allow for placement of an implant? And should we remove the retained cementum now or at the time of possible ridge augmentation?

We agreed that the best way to manage the case was to schedule exploratory surgery of the area by the Periodontist  in order to:
(1) Remove the retained cementum and
(2) assess whether ridge augmentation procedures could be performed that would allow implant placement. Should the site  (a) not be suitable for an implant or (b) if the patient preferred a different restorative solution (3 unit bridge), there still would be need for augmentation of the socket for proper aesthetics, but perhaps not to the point where it would need to support an implant.

The patient was referred back to the referring Dentist with a copy of the referral letter sent to the Periodontist.

For more information about Cemental Tears – look it up in the EndoFiles Cabinet and search for Author “Lin”, who seems to have done a lot of work in this area.

Surgical Endo Failure Due to Unusual Root Fracture

A 55 year old female patient was referred to me in late 2013 for consultation and possible treatment of tooth# 12. The patient had a history of endodontic treatment with post and core crown restoration. The tooth had subsequently been retreated surgically with root resection and Retrofilling.  . The crown root ratio was noted to be extremely low and there was a persistent periradicular radiolucent  finding associated with the apex of this tooth. A draining buccal sinus was present. I noted that the retro filling material was amalgam, which likely indicated that this surgical treatment was quite old. Furthermore, minimal filling material was noted in the canal, with a void was present between the post and canal filling material.

Clinical examination revealed slight percussive and palpation sensitivity over the apex of# 12. Periodontal probings were within the range of normal. Occlusion showed no extreme function but I was concerned regarding the crown/root ratio and the stresses that might occur should we choose to further resect the already short root There also was the issue of the metal post. Retro-preparing against a metal post cannot be done with the normal ultrasonic surgical instruments and must be done with a carbide bur. This often means further angular resection of the root to allow for surgical handpiece access in a root that was already of minimal length. Further postop stresses on the root could result in eventual fracture considering both its size and minimal root length. I was unsure of the long term prognosis.

After explaining all the options to the patient which included extraction and implant placement or bridge, the patient chose to have the area re-surgerized because she was happy with the current aesthetics of the existing crown.

Unlike the previous surgery (that resulted in scarring of the soft tissue because the incision was made in the mucosa) a classic BU flap was laid in the attached gingiva, coronal to the previous surgical incision.

 Exposure of the crypt revealed granulomatous soft tissue ingrowth into the resorbed  area at the end of the root. and irregular stained root dentin present at the root end. Insufficient tissue was available for biopsy because of its granulomatous nature. I removed only the irregular discolored area of the root resorption. The amalgam was removed and the peripheral canal area around the post root retroprepared as well as possible with ultrasonic retro tips . A small round bur was then used to remove as much of the post as possible (with the restricted access) to allow for placement of a retro filling.

In this case I was unsure as to how well a minimal thickness of MTA cement would seal so I chose to use a flowable composite- Ultradent Permaflow purple . This is the same material I use for orifice bonds. The root was etched, rinsed and a bonding agent was placed and the flowable composite was placed over the retro preparation site. At that time of resection,  I noticed a small stained  vertical fracture (white arrow)  on the palatal side of the root but since we were already committed to doing the surgery, I felt it would be best that we continue to completion and see what kind of results we could get over the long term.

The patient was brought back for suture removal and the area appeared to be healing very well.

The patient was then brought back at six months post op at which time the soft tissues looked perfectly normal and radiographic images showed that bone fill was proceeding normally. I was reasonably optimistic at this point but had some concerns regarding the long term viability of the tooth, considering the crown root ratio and the previous fracture that I had seen during the surgery. The patient refused to come in for further recalls and we were unable to examine the tooth either clinically or radiographically at 1 or 2 years postop .

In August of 2021 the referring dentist referred the patient because of the presence of a persistent draining buccal sinus at the apex of this tooth. They enclosed a radiograph and clinical photo which showed that a fragment of the apical portion root had broken off on the distal aspect. This was likely associated with the previous fracture line that I had seen during the surgery.

The tooth will now require extraction and replacement with an implant.

Considering it’s compromised nature, we got about eight years of service out of this tooth although it had both a previous surgery and presence of a fracture.

In retrospect, when I saw the fracture during the surgery, I could have recommended immediate extraction, but in the absence of any pocketing (possibly related to a VRF) we elected to try to save the tooth. 

Whenever we perform treatment on suboptimal teeth, we must always have a fully informed patient. In this case, although we eventually will lose the tooth:
(1) we kept the tooth from late 2013 until the summer of 2021 and initially got some healing of the area
(2) after treatment there was minimal compromise of the implant site and the patient can have the tooth prosthetically replaced (with a bridge or implant) with minimal bony defect.

What have we learned from this retreatment failure?

A 61-year-old male was referred for endodontic consideration of #35. The patient had #36 extracted by his dentist two weeks previously. Reason unknown. A Bridge is planned for #35-37. The referring dentist noted a radiolucent area associated with the apex of #35. Percussion, Palpation, chewing, and Periodontal findings were all within the range of normal in #35. #37 was unopposed. The endodontic treatment in #35 appeared short filled and radiography confirmed the presence of a large stainless steel post and diffuse radiolucency at the apex of the root. Clinical examination revealed an open buccal margin associated with the crown of #35. I was unsure of whether coronal leakage may be playing a factor in the Endo failure. However, the patient was asymptomatic at the time of examination. 

Although we were considering conventional disassembly retreatment to address the persistent periradicular findings, I  was very concerned that the tooth would not survive post removal attempts. Even if we did remove the post, I did not believe the remaining root would serve as a good abutment because of its compromised dentin thickness.

I spoke with the Dentist and suggested that he could simply remake the existing single crown and place an implant in the position of #36.  Placing a new crown over asymptomatic #35 (WITHOUT retreatment)  meant that the patient would have to sign off on placing a new crown over than a less than optimal Endo treatment and apical pathology. However, disassembly retreatment may leave the tooth in a poorer condition without guaranteeing resolution of the apical radiolucency. Should #35 become symptomatic in the future, we could disassemble it,  treat it surgically or extract it and restore the area with two implants (#35 and 36), rather than trying to merely replace the crown in #35.

Two years later, the patient was again referred to me for further examination. The crown had been replaced over the existing post and core. The RD noted that the radiolucent area was now larger, but the patient remained asymptomatic. I explained to the patient that we again had several options:
1. Disassembly retreatment and re-restoration 
2. Surgical treatment or
3. No treatment until symptomatic.
4. Extraction and implant replacement.
Since he had only recently had the crown replaced and was asymptomatic, the patient again chose not to retreat the Endo.

One year later the patient began to have symptoms. For the previous 2 weeks he had been  having difficulty chewing and now wished to address the problem. The RD informed me that he was planning to use #35 as an abutment for bridge or RPD.  He and the patient agreed to disassembly retreat.

Retreatment was initiated with removal of the crown, post, attempted re-clean of the canal and Ca(OH)2 medication.  (The Gutta Percha cone I placed into the canal along side the WL file in the image below was used only to help prevent the loose file from falling out when taking the WL image). The canal was found to be blocked short of the terminus.

After 1 month of Ca(OH)2 medication the area was asymptomatic and the canal obturated. A post space was left for the RD with instructions NOT to modify it. The patient did not appear for his scheduled 4 month follow up.

A 6 mo. postop radiograph was sent to me by RD that showed l improvement in the apical radiolucency. Although the area had not completely resolved, it appeared that retreatment results were moving in the right direction, and I recommended that the RD proceed with the final restoration.

Two and a half years later, the patient called to schedule an appointment for recall of tooth #35. The patient reported that the tooth has become very sore. He had avoided chewing on the left side and has developed a “pimple” on the side of the tooth.

Clinical examination revealed a draining buccal sinus and 10-millimeter probing depth on the buccal aspect of the root. Radiographic examination showed good healing of the apical radiolucency but PDL thickening was noted on the distal aspect of the root along with some vertical bone loss. This is generally consistent with the presence of a root fracture.

I told the referring dentist that #35 required extraction.  The apical area had actually healed quite well but I believed that after completion of the retreatment, it was imperative that #35 NOT be the sole functioning posterior tooth on this side after retreatment,  if it were to survive.  Without occlusion on # 26 and # 37 this premolar was at high risk of root fracture. The patient now faced the prospect of two implants, a larger bridge or RPD to replace the now missing #35 and 36.

From this case we can see that if if long term retention of the retreated tooth is the goal, Endo retreatment cases must be part of with a well thought out treatment plan that takes into consideration things like prompt post-treatment  restoration , occlusion, and function. Even the best Endo will fail if it is not followed up with the correctly designed and implemented restorative treatment.

How far does the responsibilty of the Endodontist extend?

A 58 year old female patient has been referred because a draining Bu sinus was noted during her hygiene appointment. The patient was symptomatic but the RD wants to replace the 3 unit bridge #25-27 due to mesial decay under the crown  margin of the distal abutment #27 and poor crown margins in #25.  Persistent radiolucent findings were noted at the apex of #27 and were likely associated with the draining buccal sinus. Perio probings were WNL.

The patient has also recently had #36 temporized with a temporary crown. The original core restoration appears close to the D pulp.  #37 appears to have mesial marginal caries and a poorly made crown with poor contours and overhung margins.  The patient had the work done in Eastern Europe 12 years ago and is happy with the aesthetics.

So, what is the responsibility of the Endodontist in this case?  Do were merely treat #27 with no regard to the other restorative issues present that have potential to compromise the endodontic treatment, should they not be addressed?

What factors need to be considered?
1. The need for a new bridge and endo retreatment of #27 ? OR do we just go through the crown and NOT worry about the crown margins?

2. Are we concerned about the condition of opposing #37? Will the patient’s budget allow for replacement of the  crown or should it be extracted? Will the patient’s budget allow for Endo treatment of #37 if it is necessary?  60-70% function of #27 D bridge abutment will be lost if we extract #37.

3. Possible need for Elective Endo on #36 prior to new crown restoration due to lack of core, pulp calcification/exposure or proximity to pulp? Again, will the patient have to choose between #36 and/or #37 or Both?  Financial considerations? When are these discussions to be had? AFTER referral?

The patient also had a draining buccal sinus in the right posterior maxilla that was previously addressed by me with with Endo treatment of the D abutment #17. (Post space requested postop). The bridge in this area may also may need to be redone due to the poor D crown margin. There also is an open contact between #18 and 17 and gross marginal decay under the crown of #18. (repaired with amalgam?) Do we Endo treat #18  as well and re-restore it or extract it?

WHO decides…and  WHEN?

Are we merely treating to the symptoms: Pain and obvious swelling/draining sinus? Or is there a plan for the mouth that is not merely “putting out fires”? Successful endodontics is only as good as the restorative treatment plan that follows it.

cbCT assists with case selection

A 39 year old male patient arrived with a history of sharp chewing sensitivity and elevated thermal sensitivity in a maxillary 2nd premolar. He previously had the first premolar extracted and replaced with an implant. The referring Dentist could not clearly discern the root anatomy with conventional imaging.

Virgin tooth shows mesial-distal crack that is easily stained with methylene blue dye. Tooth opposed by virgin premolar. Note adjacent premolar implant that MAY have been lost due to similar cracks. Is this a bruxism issue? Or perhaps an unlucky event with hard food?

cbCT shows 3 canal premolar with 3 separate roots.  Examination of the bite wing and adjacent proximal bone showed normal anatomy. This was consistent with the relatively normal proximal periodontal probings.  This information not only allowed us to anticipate canal anatomy but it also helped to evaluate the prognosis. Although the tooth had cracked, the cracks did not appear severe enough at this stage for us to consider extraction rather than Endodontic treatment and restoration with full cuspal coverage,

Off angle view of access showed the stained crack lines extending roughly to the CEJ.  Final obturation with vertical compaction of warm gutta percha. Access sealed with Rebilda DC Bonded core paste. Patient advised to have crown placed STAT!!