Asymptomatic Menace

Returning from an endodontic symposium last month, there was a lot of talk around external cervical resorption (ECR) and its management. The etiology and predisposing factors still remain partly shrouded which tends to confound many of us as clinicians in the realm of diagnosis and treatment. Shannon Patel et al. (J Endod 2009;35:616-625) did an excellent review of ECR whereby they identified that effective management could be performed if the nature, location and extent of the lesion was fully known.

The etiology of ECR is accepted to be damage or deficiency to cementum that allows contact of dentin with osteoclasts. Patel notes that microscopic studies have shown that there can be anatomical gaps between enamel and cementum, but that the possibility for damage to this area has also been shown to be a source. The most commonly detectable sources of damage were trauma, orthodontic treatment and intracoronal bleaching. What was not noted was the roll of traumatic occlusion in the form of bruxism and a fraction lesions, though about 15% of cases were not identified to have a source. Anecdotally, there appears to be a higher incidence of cases presenting to our practice where ECR occurs cervical to working cusps on patients with signs of severe parafunctional habits. Perhaps this is something we could be looking for in addition to caries this this subgroup population.

Excessive orthodontic forces, Patel notes, may be responsible for localized necrosis and resulting inflammation adjacent to exposed dentin. A review of orthodontic techniques showed no difference in the prevalence and it was also noted that excess orthodontic forces appeared to cause immediate blunting of the roots rather than ECR years to decades later.

In luxation and avulsion injuries ECR is known to be common. Heithersay’s 1999 study noted 15.1% of ECR could be attributed to these types of injuries. This increased if intracoronal bleaching or orthodontic movement were attempted. Patel cited a well-known Andreasen study as the basis for repositioning/splinting these teeth with as gentle forces as possible to allow for PDL healing and decrease the potential for ECR.

Patel also reviewed how intracoronal (internal) bleaching could predispose ECR. Rotstein was able to show that peroxide could escape the pulp chamber through dentinal tubules into cementum defects. This could be mitigated by placing a glass ionomer or composite seal to the cementoenamel junction.

A minor cause of ECR, Patel notes, was that 1.6% of cases were identified to have periodontal therapy as their sole predisposing factor.

In making a diagnosis, these lesions are almost always asymptomatic because they lay below the sulcus and do not contact the pulp. Despite perception, there frequently remains a layer of predentin surrounding the pulp. Patel comments that early lesions are often not diagnosed until he “pink spot” of highly vascularized granulation/resorptive tissue is spotted under enamel. Larger lesions tend not to probe as the granulation tissue inflames, so profuse bleeding can be expected. Patel concludes that early detection by radiograph and subsequent confirmation by CBCT is the most reliable form of detection and diagnosis.

Treatment of these lesions will depend upon the location and severity, with more options and better prognosis in earlier stages. The progression does not proceed linearly, so “watching” these lesions is inadvisable. Patel notes that there are several case reports in the literature but that a common theme isremovalof the resorptive lesion with restoration with a biocompatible material and possible endodontic therapy if the pulp becomes involved during treatment. Heithersay

Progression of External Cervical Resorption

Progression of External Cervical Resorption

classified types of ECR and made recommendations that only Class 1-3 (those without additional resorptive perforations beyond the coronal third) should be treated to achieve a good prognosis.

Patel concludes with her review that early detection and initiation of treatment is critical for successful treatment. If a localized etiology cannot be identified, then the entire dentition should be evaluated. Once identified, CBCT imaging is an important diagnostic tool to determine the extent, classification, treatment options and prognosis.

Dr. Jason Conn

Dr, Jason Conn, DMD, CAGS, FRCD(C)

ABOUT Dr. JASON CONN, DMD, CAGS, FRCD(C) – LANGLEY ENDODONTICS

Dr. Conn was born and raised in Langley. He completed a Bachelors in Chemistry at Simon Fraser University before receiving his DMD and Certificate of Advanced Graduate Study in Endodontics at Boston University where he wrote a thesis in clinical decision making and another in odontogenic stem cell differentiation.

Dr. Conn has maintained an active practice alongside Dr. Bittner since 2012 while teaching as a part-time clinical assistant professor at the University of British Columbia.

In his free time, Dr. Conn is a Cub Scout leader, long distance runner, back-country hiker, snowboarder and yogi-in-training.

 

On November 21, 2016, posted in: News for Doctors by

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