Monday, October 29, 2007

Cracked Teeth

Here are a few teeth that I have seen in my practice. Some of them were treated endodontically, and others simply needed cuspal coverage. It is my recommendation that when you find teeth like these, that have cracks and signs of stress, that you recommend cuspal coverage. Before crowning them, I would recommend a thorough endodontic evaluation, including percussion, biting (tooth sleuth), probing and thermal testing to evaluate pulpal status. If the tooth passes all of these tests and the pulp is normal, then I would recommend cuspal coverage.

Even though these amalgams are conservative, multiple enamel cracks are evident. Signs of stress are everywhere. This tooth needs cuspal coverage before it becomes necrotic, fractures a cusp, or develops a fractured root.

Cracks like these through the marginal ridges generally extend down the pulpal wall.

When you find a tooth that has cracks on the mesial and distal marginal ridge, the tooth is under extreme forces. If left untreated, the buccal and lingual sides of this tooth will continue to flex and the cracks will eventually meet in the middle and the tooth will become non-restorable.

I'm no practice management guru, but I know if you identify the cracked teeth already in your practice, do proper endodontic evaluation, and protect your patient's teeth with cuspal coverage, you will be doing them a great service and building your practice at the same time. If your patients question the need for cuspal coverage of cracked teeth, send them over for a consultation with your endodontist. We see teeth everyday that could have been saved if they had only been crowned earlier.

This last image is what I call the "Past, Present & Future Cracked Tooth". Past (#3-extracted), Present (#4-buccal cusp fracture), Future (#5-MMR crack waiting for buccal cusp to fracture). Proper diagnosis & treatment will save your patients time and money.

Friday, October 26, 2007

Resorption of Endodontic Sealer

Endodontic sealers play an important role in the obturation (filling) of a root canal. The sealer coats the walls of the canals and fills the space between the root canal filling material and the root. Their antimicrobial activity likely plays a very important role in the overall documented success of endodontic therapy.

There are many kinds of endodontics sealers. They can be grouped into these categories:
1. Zinc Oxide-Eugenol (Roths)
2. Chloropercha (Kloroperka)
3. Calcium Hydroxide (Sealapex, CRCS, Apexit)
4. Polymers (AH26, AHPlus, Diaket, Endofill, Resilon)

I am using a Roth's sealer in my practice. Here are a couple of reasons that I like using a Roth's sealer.
1. Antimicrobial - the Zinc oxide has well known antimicrobial activity
2. No need to remove the smear layer - since I am using a gutta percha filler, I prefer to leave the smear layer
3. Resorbabilty - any sealer that is extruded past the apex will resorb over time.

Here is an example of a case where a significant amount of sealer was extruded.

At a 2 year recall, you can see that the majority of the sealer has resorbed.

Thursday, October 25, 2007

Pulling a Pulp

The dental pulp tissue is the living tissue inside of the tooth. It is made of blood vessels, nerve, lymph & connective tissue.
If this tissue become inflammed or necrotic (dead), it must be removed. Occasionally, the pulpal tissue might be completely healthy, but because the remaining tooth structure is too weak, we electively remove the pulp, complete a root canal for "restorative purposes". In other words, we remove the pulp, so that we can use the internal structure of the root to help build up the tooth in preparation for a new crown.
This video clip shows the removal of the dental pulp from a tooth required endodontic treatment for restorative purposes.

Tuesday, October 16, 2007

Cracked Tooth

When a crack extends from the occlusal (chewing) surface towards the root, we call it a cracked tooth. These cracks may be very small or very large. The crack often causes damage to the pulp of the tooth. Primary symptom of a cracked tooth is pain upon chewing. This pain may be irregular and sporadic.

The depth and position of the crack determines whether the tooth is restorable. If the crack is in the coronal portion of the tooth, then placing a crown with prevent futher flexing of the tooth as well as prevent bacterial leakage through the crack.

A crack extending down the root surface is also commonly referred to a root fracture. Root fractures can be difficult to diagnose. Often they are associated with a deep, narrow, periodontal defect. However, a draining abscess can also cause a deep narrow pocket, which can easily be confused with a root fracture.

In the picture above, the extracted tooth has been dyed. The periodontal ligament picks up the stain. You can see that in the area of the crack, the pdl has broken down and a deep, narrow periodontal defect has developed on the line of the crack.

A cracked tooth that is not treated will worsen and lead to loss of the tooth. Early diagnosis and treatment are essential in preserving these teeth.

Friday, October 5, 2007

Dentigerous Cyst

This patient was referred to my office for endodontic evaluation. The patient had a prior RCT with some localized, intermittent pain & swelling.

My clinical exam revealed #31 normal to percussion, perio defect on distal >14mm. Radigraphs revealed resorption of the distal root, and extensive bone loss on the distal of #31. Due to the strange resorptive pattern and bone loss around the impacted wisdom tooth, the tooth was referred to a surgeon for evaluation.

The oral surgeon performed an incisional biopsy with extraction #32.
The lesion was diangosed as a dentigerous cyst. Following this diagnosis, the patient was again seen for a excisional biopsy.

Pathology Review: Dentigerous Cyst is the most common developmental odontogenic cyst. It is a cyst that comes from the separation of the follicle from an uneruped tooth. This cyst encloses the crown of an unerupted tooth and is attached to the tooth at the cemento-enamel junction. These cysts are most commonly involve the Md third molars and secondly the Mx canines. These cysts can grow quite large and can cause painless expansion of the bone and also displace an involved tooth. About half of the time, this cyst will cause root resorption. Treatment includes enucleation of the cyst with the removal of the unerupted tooth. Marsupialization occasionally done with very large cysts to decompress the cyst. Prognosis is excellent and recurrence is rare if completely removed. There has been some discussion of dentigerous cysts that have undergone neoplastic transformation to ameloblastoma or other neoplasm. (Source: Waldron, Charles. Oral & Maxillofacial Pathology, 493-495, 1995)