Regenerative Potential of Dental Pulp

Resident: J. Hencler
Date: 10/20/2010

Article title: Regenerative Potential of Dental Pulp
Author(s): Martin Trope, DMD
Journal: Pediatric Dentistry V30/ No 3 May/Jun 2008
Major topic: Pulp regeneration
Type of Article: Conference paper

Main Purpose: Explore the potential for pulp regeneration as a routine dental procedure.

Background: The inflamed pulp unexposed by caries or trauma has potential for repair. Our diagnostic ability to differentiate vital from necrotic is good, but reversible from irreversible inflamed pulp remains an educated guess. The younger the pulp, the better it’s repair potential. Vital therapy (pulp capping, partial or full pulpotomy) on traumatically exposed pulps is very successful, whereas vital pulp therapy on cariously exposed tooth is not nearly as successful. The difference in success rates is explained by the status of the pulp at the time of the procedure. A very important factor in the success of treating a vital exposure is the coronal seal. PEDO approach: B/c the young vital pulp has good potential for repair, it is accepted to perform an indirect or direct pulp cap on a carious exposure as long as a ideal coronal restoration can be placed. ENDO approach: Perform a full pulpotomy and treat the presumable healthy pulp at the canal orifices. When the root canal has developed thick dentinal walls and apices are closed, a full pulpectomy can be performed.

Pulp Revascularization: Revascularization of an immature necrotic tooth has many potential advantages. It has been shown that under certain conditions revascularization can be achieved in young teeth that have been traumatically avulsed, leaving a necrotic but uninfected pulp. Attempting to reproduce these conditions when the pulp space is infected could possibly lead to revascularization of an infected pulp. It has been experimentally shown that the apical portion of the pulp might remain vital and proliferate after reimplantation, replacing the necrotized coronal portion of the pulp. The ischemically necrotic pulp that is unique to an avulsion injury acts as a scaffold into which the new tissue grows, and the fact that the crown is usually intact slows bacterial penetration. Revascularization of the pulp space in a necrotic, infected tooth w/ apical periodontitis in the 1960’s but was unsuccessful. A more recent case report found that it might be possible to replicate the unique circumstances of an avulsed tooth to revascularize the pulp in infected necrotic immature roots. CASE DETAILS: An immature 2nd lower right pre-molar presents with radiographic and clinical signs of apical periodontitis w/ presence of sinus tract/fistula. The canal was disinfected w/out mechanical instrumentation but w/ copious irrigation w/ 5.25% sodium hypochlorite and the use of a mixture of ciprofloxacin, metronidazole, and minocycline. A blood clot was produced to the level of the CEJ to provide a scaffold for the in growth of new tissue followed by a double seal of MTA in the cervical area and a bonded resin coronal restoration above it. The large radiolucency had disappeared w/in 2 months and at the 24-month recall it was obvious that the root walls were thick, and the root development continued. The antibacterial effectiveness of the tri-antibiotic paste was confirmed in a study using a dog model w/ infected immature roots. This study also showed that a blood clot was essential as a scaffold. It is unknown what factors in the blood clot are important, but if isolated, they can be incorporated into a synthetic scaffold that will be easier for clinicians to manipulate compared to a blood clot.

Summary of conclusions: Recreating the pulp conditions of a young avulsed tooth may be the key to pulp revascularization in carious infected pulps.

Assessment of article: Great article, very interesting.