Proper protection for non-vital bleach cases - A Case Study
The increase in the demand for cosmetic services has resulted in more bleaching treatments being performed by General Practitioners. In the case of the Endodontically treated tooth, internal bleaching techniques such as the Walking Bleach Technique are often used to improve the cosmetic appearance. Proper use of these caustic bleaching solutions can have real benefit. However, when used improperly and with inadequate protection of the root canal filling material, they can cause catastrophic external resorption. I came upon an example recently. Discolored #21 (US #8) had a history of traumatic episode and 8 year successful NSRCT. The patient requested Cosmetic improvement. One year previously, the tooth had an internal bleach attempt with no protection of the gutta percha filling. Percolation of the bleach into the unprotected dentinal tubules resulted in circumferential external resorption to the level of gutta percha. Percussion tests suggested possible ankylosis. The tooth was now intruded as well. Periodontal findings indicated generalized loss of attachment to the level of the gutta percha. The prognosis was grim. Compounding the situation was the presence of virgin proximal teeth. I very much wished to avoid preparation of these virgin teeth for a 3 unit fixed bridge.
We elected to extract and place a single tooth implant. Surgical removal of the tooth required osseous ridge augmentation to ensure adequate aesthetics. The process was complicated, lengthy and costly. It also placed the Endodontist in the precarious position of having to explain why the referral's apparently successful 8-year-old endodontic treatment had suddenly become symptomatic after the tooth was bleached. All of this could have easily been avoided had adequate protection been placed before application of the bleaching agent. Protection is best provided by the use of a well sealing glass ionomer or composite restoration of 4mm minimum thickness. This can be removed and replaced after the bleach, if necessary.
Clinicians performing internal bleach techniques must be aware of the potential adverse effects of these caustic agents. In the case of traumatized teeth, patients must always be informed of the potential risks of any treatment. Failure to provide adequate protection of the root canal filling material can lead to embarrassing loss of teeth with apparently successful endodontic treatment.