Retreatment & MTA Save a Perforated Tooth

The following case was submitted by Dr. Rico D. Short of Smyrna, GA.

Original endodontic treatment was done 15 years ago. The crowns on 8 & 9 were replaced 2 years earlier at which time the dentist placed post for retention. During post preparation, the root was perforated. A large lesion has developed.


DX: Prior RCT w/ Chronic Apical Abscess w/ root perforation. Pt was informed the prognosis was questionable due to the perforation. Pt understood and consented for treatment including perforation repair.

Retreatment on #8 completed with MTA root repair.

8 month recall

22 month recall finds patient asymptomatic and functioning with no mobility and normal probing depths.

While many clinicians would have deemed this tooth "hopeless" and recommended extraction, MTA, microscopes and a expert clinician can save teeth that otherwise would be extracted.

Endodontic Retreatment & MTA Preserve the Tooth

Here's a tooth that had endodontic treatment over 10 years ago. While the clinician had difficulty finding all the canals, the tooth has been functional for quite some time. A large furcal defect raises suspicion of a root fracture or perforation.

DX: Prior RCT w/ Symptomatic Apical Periodontitis.

There are many who would consider this hopeless and recommend extraction.

Let us consider the cause of this treatment failure:

1. Missed Canals

2. Furcal Perforation or Root Fracture?

Can these issues be addressed to preserve the natural tooth?

In my consultation with the patient, I explain these issues and that endodontic re-treatment may be able to save the tooth (as long as the root is not fractured). I also explain the alternative option of extraction.

Finding missing canals is a simple solution.

A perforated root can be repaired with guarded prognosis.

A fractured root will require extraction.

I tell the patient the only way to know for sure is to open the tooth and investigate. Considering the nice crown on the tooth, the cost of attempting to save the tooth is minimal, compared to the cost of removing and replacing. In this case the patient elected re-treatment.

Pre-operative radiograph.

Upon access, 2 additional canals are located and instrumented. A furcal perforation is also identified. No root fractures are found.

Re-treatment is complete. Canals obturated with gutta percha and furcal perforation repaired with MTA. Glass ionomer base is placed over MTA.

7 month recall shows a tooth that is fully functional with remarkable healing of the furcal defect. Endodontic re-treatment has preserved the natural tooth.

Apexification with Calcium Hydroxide & MTA Fill

This 15 year old patient has a history of trauma to #8. Trauma occurred at an age before apical closure occurred. Tooth was diagnosed with necrotic pulp and symptomatic apical periodontitis. Note the large periapical lesion.

Traditional apexification using Ca(OH)2 was used.

Tooth debrided to the apex, NaOCl irrigation.

Ca(OH)2 placed.

3 month check shows resorption of Ca(OH)2, but apex still open. Apical lesion almost completely healed.

Ca(OH)2 placed again.

10 month re-evaluation. Apical barrier present, so it was time to obturate. This is a great view of the apical barrier that has formed.

Tooth was obturated with MTA. If this tooth ever needs apical treatment, a simple resection will be done without retropreparation or retrofilling.

Research Update: Use of MTA for Direct Pulp Capping

In a recent post, we have discussed the use of MTA as a pulp capping agent.

A recent article by Yasuda, Ogawa, Arakawa, Kadowaki and Saito entitled "The Effect of Mineral Trioxide Aggregate on the Mineralization Ability of Rat Dental Pulp Cells: An In Vitro Study" may shed some light on the reasons MTA may be more effective than calcium hydroxide for direct pulp capping.

Direct pulp capping is an effort to maintain the vitality of a dental pulp following exposure during excavation and thereby avoid endodontic therapy. The formation of a dentinal bridge over the exposed pulp surface is the goal while maintaining pulpal vitality.

Conventional pulp capping treatment included medicating the exposed pulp with calcium hydroxide (ie. Dycal) prior to restoration. Calcium hydroxide is known to cause an inflammatory reaction of the dental pulp. Appication of adhesive resins has also been attempted. Incomplete dentinal bridges has been found with a lack of published long term clinical results.

It has been reported that MTA induces the formation of dentinal bridging with little or no inflammation. MTA is known for it's biocompatibility and lack of cytotoxicity. Tani-Ishii et. al. reported that MTA upregulated the expression of type I collagen and osteocalcin in osteoblasts.

Bone morphogenic proteins (BMP's) are crucial to bone and collagen formation. BMP-2 and it's receptor are expressed in the dental pulp. BMP-2 has been shown to accelerate the differentiation of human pulp cells into odontoblasts. This study hypothesized that BMP-2 is involved in the MTA induced mineralization.

This study found that MTA significantly stimulated mineralization (in rat dental pulp cells) by 60% compared to the controls. MTA and Dycal both significantly upregulated by 2-fold the level of BMP-2 mRNA compared with the controls. MTA increased the BMP-2 protein production by 40% while Dycal significantly reduced it. The authors suggest that BMP-2 may play an important role in mineralization stimulated by MTA.

MTA has shown promise as a direct pulp capping agent which may improve the success of direct pulp capping over convention calcium hydroxide techniques.

Sources:
Yasuda, Ogawa, Arakawa, Kadowaki, Saito. "The Effect of Mineral Trioxide Aggregate on the Mineralization Ability of Rat Dental Pulp Cells: An In Vitro Study". JOE 2008; 34:1057-1060.

Tani-Ishii, Hamad, Watanabe, Tujimoto, Teranaka, Umemoto. "Expression of Bone Extracellular Matrix Proteins on Osteoblast Cells in the Presence of Mineral Trioxide". JOE 2007; 33:836-839.