CBCT as a Tool in Endodontic Diagnosis

Cone Beam Computed Tomography (CBCT) is a valuable tool in endodontic diagnosis. The following case illustrates how CBCT provides added diagnostic information not available through traditional 2D imaging.

This patient was referred to our office today after a long week of infection and diagnostic dilemmas. Here's the story...

10 days ago with an ear ache.
9 days ago pt reports pain to chewing & closing teeth together.
8 days ago swelling began. Pt went to ER and was given zithromax, ibuprofen & tylenol #3.
7 days ago swelling increased under tongue and into face.
5 days ago, pt returned to ER where they did a CT scan and found nothing. Pt reports numbness in lip. Pt admitted to hospital and given IV clindamycin. MRI done and "something was found in lower left jaw". Pt started 300mg clindamycin.
Today, patient referred from oral surgery for endodontic consult/vitality testing. Here's how he looked.




Radiographs fairly inconclusive. #18, #19, #20, #21 all normal to percussion, probing and thermal testing.

A small crack noted on the distal marginal ridge of #18. Thermal testing once again indicates a vital pulp. Typically, we would expect a necrotic tooth to be the source of the submandibular swelling that this patient has experienced.

Since tooth #18 is responding normally to thermal testing, we decided to take a CBCT to look for more evidence of the source of infection.

This coronal slice (.25mm) shows radiolucency around the distal root #18. This image is more conclusive than the standard 2D image.

A sagittal slice through the distal root of #18 shows the lesion and its perforation of the lingual plate.

An axial view of the distal root of #18 also shows perforation to the lingual.

These CBCT slices are conclusive enough to revise the pulpal diagnosis to "partially necrotic" and recommend endodontic treatment. It appears that the distal root is necrotic and the infection is spreading through the lingual plate.

RCT initiated. Upon access, we find vital pulp tissue in the mesial canals, and necrotic pulp tissue in the distal canal.

Further removal of the distal crack finds the crack extending down the distal root, below the CEJ. Extraction is recommended.

In endodontic diagnostics, we typically classify pulpal status as:

1. Normal
2. Reversibly Inflammed
3. Irreversibly Inflammed
4. Necrotic

However, things are not always a cut an dry as that. This case illustrates that "partially necrotic" pulp is a possible classification of pulpal status.

Following removal of the tooth, the infection quickly resolved.

CBCT is an important tool for diagnostic imaging in endodontics.

CBCT to Evaluate Internal Root Resorption

CBCT can be used to evaluate the extent of root resorption. Before this technology, we would have to excavate a resorptive defect to evaluated the extent and restorability. The CBCT allows us to see in all dimensions the extent of a resorptive defect. In this case, the non-restorability was determined with CBCT alone. This saves the patient and clinician time and money.

This video is made of individuals slices 1.0mm thick with 0.25mm interval between each slice.

CBCT to Diagnose Sinusitis of Dental Origin

The CBCT can be used to make a diagnosis of sinusitis of dental origin.

Successful Perforation Repair using MTA

This patient presented for treatment of #30 in March 2009. Prior RCT had been done and a large furcal lesion as well as periapical lesion were noted. Retreatment was recommended. Upon access, we found 2 additional canals as well as a furcal perforation. The tooth was obturated and perforation was repaired using MTA.

Post-Op films shows the MTA repair in the furcal area. Note the large lesion around the mesial root.

At 6 months, furcal and periapical lesion are improving and the tooth is functional.


At 18 months, the lesion continues to improve, tooth is completely asymptomatic and functional. Proper endodontic treatment and repair with MTA has retained a tooth that many would have considered "hopeless" or non-restorable based on the amount of furcal bone loss.

Superstition Springs Endodontics goes 3D

Superstition Springs Endodontics is excited to introduce cone beam technology (CBCT) into their practice of endodontics. The decision to incorporate this technology has come after a extended review of the technology, research and clinical applications of CBCT in endodontics.

Dr. Edward Carlson was among the first endodontists in Arizona to incorporate the operating microscope into his practice of endodontics almost twenty years ago. Just as the operating microscope has become an indispensable tool in the practice of endodontics, we expect CBCT to become integral part of endodontic diagnosis, treatment & evaluation.

As Superstition Springs Endodontics, we are specialists in saving teeth. The CBCT is another diagnostic tool to allow us to make important decisions about saving teeth. Doctors and patients who are committed to saving natural teeth, will be able to benefit from this new technology.

The clinical applications of CBCT in endodontics include:
1. Aid in endodontic diagnosis
2. Canal morphology
3. Evaluation of root fracture
4. Evaluation of internal root resorption
5. Evaluation of invasive cervical resorption
6. Presurgical assessment
7. Evaluation of non-endodontic pathology
8. Assist with implant planning for non-restorable teeth

We look forward to sharing cases using this new technology.

The first case to share is the case of a fractured tooth. This patient had a fall and hit her face 5 months ago. #8 was damaged and had to be removed and replaced with an immediate implant. #9 continued to give her symptoms and mobility.

Now it is obvious with a regular radiograph that there is a problem with this root. The tooth exhibited class II mobility.


The coronal view (left) shows the similar view to the standard radiograph, however, the sagittal view (right) shows how the fracture has sheared off toward the palate, well below the level of palatal bone. The ability to see this fracture from the sagittal view allows us to make a determination of the restorability of this tooth.

Previously, we would have had to remove the fractured portion of the tooth and visualize the depth of the fracture. The CBCT allows us to visualize this without the need to disassemble the tooth. This tooth has been recommended for extraction and the CBCT scan can also be used to help in the treatment planning of the new implant.

Stay tuned for more applications of CBCT in our endodontic practice.

We have selected a CBCT manufactured by J. Morita. J. Morita has been a leader in development of cone beam technology. The Veraviewepocs 3De is a focus field cone beam with incredible resolution, ideal for the practice of endodontics.

An inexpensive solution for transillumination

At the most recent Inner Space Seminar, we discussed all different kinds of cracks in teeth. We reviewed how to detect them, classify them, treat them, & prevent them. An effective way to identify cracks in the crown of a tooth is by using transillumination.

I mentioned an inexpensive light that can be used for transillumination. Thanks to Dr. Nathan Saydyk for his research, this light has been discontinued and replaced with the new Browning 2120 Microblast Pen Light with Bore Light Adapter. This is a flashlight used for firearm inspection and cleaning that can be used for transillumination.

Managing a Cracked Tooth

Dealing with cracked teeth can be very challenging. In the first place, there is a lot of confusion about what we are calling a cracked tooth. Craze lines, fractured cusps, split teeth and vertical root fractures are all often called "cracked" teeth. However, treatment and prognosis are different for all of these different situations.

Cracks in teeth are findings, not a diagnosis. Proper pulpal and periapical diagnosis as well as the location and extent of a crack are needed to determine a proper treatment plan. The problem with cracks in the tooth are the possibility for future bacterial penetration, which leads to inflammation and disease.

With these considerations, many teeth with cracks can be saved. Keys to saving teeth with cracks are:
1. Early detection and treatment
2. Proper endodontic diagnosis
3. Proper determination of the location and extent of a crack

The following case of a cracked tooth was recently treated at Superstition Springs Endodontics.

This patient presented with mesial decay on #14 causing discomfort. The tooth was normal to percussion, probing and no response to thermal test. DX: Necrotic pulp w/ normal periapex. A crack was noted on the distal marginal ridge. RCT recommended.

Removal of decay and access revealed the crack extending down the distal wall.

Closer examination finds that the crack ends near the level of the CEJ. Pt is informed of the crack and the prognosis is good, since the new crown will be able to cover the crack. The crack should be removed at the time of the build-up.

A main key to saving teeth with cracks is to identify the location and extent of a crack.

An upcoming Inner Space Seminar, entitled "Breakdance" will help clinicians know how to identify and classify cracks in teeth, as well as treatment plan restorative options for teeth with cracks.

Would you implant or do RCT? - UPDATED

I work with some great oral surgeons & periodontists. I was recently asked to evaluate tooth #31 by my periodontist colleague. This patient had been referred to him for extraction and placement of an implant.

The periodontist realized that the bone loss around this root was not caused by periodontal disease. The patient reported no pain or swelling. He has no senstivity to percussion, normal probing depths (4mm depth on the buccal was the deepest) and when proper vitality testing was completed, the tooth was found to be necrotic. The tooth was diagnosed: Necrotic Pulp w/ Chronic Apical Periodontitis. The patient was given the option of endodontic therapy to retain the natural tooth.

Pulpal access revealed a necrotic pulp chamber.

Endodontic therapy completed and a 6 month recall scheduled to evaluate the periapical healing.
Please feel free to share your thoughts about these cases. The purpose of this blog is to generate discussion. What would you have done?

OK, here we are 3 years later. The tooth is asymptomatic and functional and perio probings are normal. Significant healing has occurred. There is still some lateral radiolucency - widened pdl, but at this point I think it was a good decision to retain the tooth.

Our specialty at Superstition Springs Endodontics is saving teeth.

Clinical Clues for Identifying Cracked/Fracture Roots

Accurate diagnosis of a cracked/fractured root is a difficult task. It is important to get it right, because the treatment for a cracked root is usually extraction. I explain to patients that there are some clinical signs that would indicate a cracked root, but they are not 100% conclusive all the time. These same clinical signs can occur in other situations as well.

The typical signs associated with a cracked/fracture root that we have previously reported:

1. J-shaped lesion or large lateral lesion

2. Deep, narrow periodontal pocket

A couple new clinical signs that I have not previously reported include:

3. Swelling in the in the marginal gingival, adjacent to the fracture

4. Failure of a swelling to resolve despite a course of antibiotics

The more of these clinical signs I see in one patient, the more confident I am that the root is cracked/fractured.

I explain to patients that the only way to know with certainty is to visualize the crack. This is most effectively done with magnification. This can either be done through an endodontic access, or through a small periodontal flap to examine the root surface. I expect that with time, CBCT will be better able to help us in the diagnosis of cracked/fractured roots. At this time, the CBCT does not appear pick up on a cracked/fractured root until the pieces of the root begin to separate.

Here is an example of a case in which several of the described clinical signs were present indicating a cracked/fractured root. Access and visualization confirmed the diagnosis of cracked root.

Pt presents with a swelling in the marginal gingiva adjacent to distal root of #19. The radiograph shows a large, lateral lesion on mesial of distal root. Patient had been taking Penicillin for several days, without resolution of the swelling. Antibiotic was changed to clindamycin to see if swelling would resolve.

Swelling did not resolve after taking clindamycin.

At this point, I am quite certain I will find a cracked root. If this were simply a perio issue or an endo issue, I would have expected it to clear up with the antibiotics.

Access into pulp chamber exposes a vertical crack/fracture on the MB root as well as the DB root.

The tooth is deemed non-restorable and extraction recommended.

If you are unsure if a tooth has a cracked/fractured root, contact your endodontist. Not all teeth can be saved, but endodontists are the specialists for saving teeth and can help you determine which ones to save.

Upgrading your Root Canal

This root canal was originally done in 1965. A periapical lesion has developed. While the root canal filling is weak and the apical seal obviously an issue, the tooth is and has been fully functional.

Removal of previous gutta percha show obvious corrosion and leakage.

It is likely that the tooth had an apicoectomy, due to the short length of the root and open apex.
The open apex is debrided and a new apical stop is created.

The canal is then obturated with MTA. MTA is chosen as the obturation material due to the open apex and the ease of future apical surgery if needed. I call this a "root canal upgrade". Preserving this tooth preserves the periapical tissues and helps to maintain the bone around the tooth. While there are lots of good replacements for missing teeth, nothing preserve the periapical architecture as well as a healthy tooth & periodontal ligament.