What are the current standards for treatment of permanent teeth that have had trauma and require apexification?

This question was submitted by a general dentist: What are the current standards for treatment of permanent teeth that have had trauma and require apexification?

Drs. Michael Casas and Suham Alexander provided this quick initial response. 

Dr. Michael Casas is Associate Professor in the Faculty of Dentistry at the University of Toronto and Director of Dentistry Clinics at SickKids Hospital. 

Traumatic dental injuries account for approximately 5% of the dental treatment sought by patients. They can be challenging for clinicians as proper diagnosis, treatment and follow-up are essential in leading to a favourable outcome.

Apexification is the process of inducing apical root closure in a necrotic immature tooth. For traumatically-induced pulp necrosis, the tooth requiring apexification is most commonly an incisor.

Treatment options

Frank Technique

In this traditional approach, calcium hydroxide is placed in a lightly cleansed canal to induce apexification. The calcium hydroxide is replenished every 3-6 months within the canal. It has been shown that it requires approximately 18-24 months of active treatment to gain adequate apical closure before gutta percha obturation can be performed.

However, this long-term treatment can be unpredictable with respect to the formation of an apical seal and duration of treatment. Also, the treatment period required to achieve an apical seal is variable and leads to difficulty in following up with patients appropriately.

Apical Plug

Mineral Trioxide Aggregate (MTA) has been effective in inducing apexification of roots when used as an apical plug. Treatment with MTA has the advantages of shorter treatment time and fewer patient appointments as well as more predictable outcomes in creating an apical barrier especially in immature permanent teeth with necrotic pulps. However, similar to treatment with calcium hydroxide, MTA only addresses the creation of an apical seal and not root formation along the length of the root.

Antibiotic Therapy in Revascularization/Revitalization

The use of antibiotic mixtures as intracanal medicaments to cleanse and “sterilize” the canal has become increasingly popular. The necrotic tooth is commonly filled with a combination of metronidazole, ciprofloxacin and minocycline. After 3 months, the canal is accessed again and bleeding is induced to fill the canal with blood and sealed with a collagen plug, MTA and then amalgam.

The blood clot creates a biological scaffold to aid in the growth of new tissue within the canal space. Additionally, the growth and differentiation factors within the blood clot support the healing process. More recently, some techniques utilize blood which is drawn from the patient and centrifuged to isolate platelet-rich plasma (PRP) or plasma-rich growth factor (PRGF) which is, then, injected into the canal. Although, the treated tooth appears radiographically to develop a typical root shape, animal studies suggest that the new tissues are not dentin and pulp but rather cementum with bony islands and connective tissue.

References

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2. Bakhtiar H, Vatanpour M, Rayani A, Navi F, Asna-Ashari E, Ahmadi A, Jafarzadeh H. The Plasma-Rich in Growth Factor as a Suitable Matrix in Regenerative Endodontics. The New York State Dental Journal. 2014. June/July: 49-53.
3. Gungor HC, Uysal S, Altay N. A retrospective evaluation of crown-fractured permanent teeth treated in a pediatric dentistry clinic. Dental Traumatology. 2007; 23:211-217.
4. Shabahang S. Treatment Options: Apexogenesis and Apexification. Pediatric Dentistry. 2013; 35(2): 125-128.
5. Thibodeau B, Trope M. Pulp Revascularization of a Necrotic infected Immature Permanent
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7. Cvek, M. Treatment of non-vital permanent incisors with calcium hydroxide. I Follow-up of periapical repair and closure of immature roots. Odontol Revy. 1972;23(1) 27-44.
8. Wang X, Thibodeau, B, Trope M, Lin HM, Huang GT. Histologic characterization of regenerated tissues in canal space after the revitalization/revascularization procedure of immature dog teeth with apical periodontitis. J Endod. 2010 Jan 36(1):55-63.