Pulp Revascularization of a Necrotic Infect Immature Permanent Tooth: Case Report and Review of the Literature

Author(s): Blayne Thibodeau, DMD, MS; Martin Trope, DMD
Journal: Pediatric Dentistry
Volume (number): 29(1)
Month, Year: Jan/Feb 2007
Major topic: pulpal revascularization in a necrotic immature permanent tooth
Type of Article: case report
Main Purpose: to present a method for inducing pulpal revascularization in a necrotic tooth with an immature apex.
Overview of method of research: A 9 year old boy presented to the endodontic emergency clinic at the University of North Carolina School of Dentistry for treatment of maxillary anterior swelling associated with tooth # 8. The patient had suffered dental trauma 2 years ago and tooth # 8 sustained a complicated crown fracture that was treated with a Cvek pulpotomy approximately 48 hours after the accident. Follow-up care had been sporadic until the patient presented for emergency care. The tooth did not respond to cold testing, but tested within normal limits for percussion, palpation, and probing depths. The tooth was diagnosed with a necrotic pulp, and the acute periapical abscess was treated with incision and drainage. At the subsequent appointment, the tooth was isolated with a rubber dam and disinfected with Betadine. The canal was accessed, irrigated with sodium hypochlorite, and dried with paper points; the canal was not instrumented. A paste made of equal parts of metronidazole, ciprofloxacin, and cefaclor mixed with sterile water was applied to the canal space with a lentulo spiral and tamped down. The access was closed with cotton pellets and IRM. The patient returned 11 weeks later for treatment and was asymptomatic. The tooth was again isolated with a rubber dam and disinfected with Betadine. The antibiotic paste was irrigated away with sodium hypochlorite and sterile water; the canal space was not instrumented. Bleeding into the canal was induced from the apical tissues using a sterile endodontic file. It took approximately 15 minutes for the blood clot to reach the level of the CEJ. MTA was mixed with sterile water, applied to the clot, and covered with a moist cotton pellet. After an hour, the cotton pellet was removed and the MTA exhibited a hard set. An acid etch composite restoration was placed and the rubber dam was removed.
Findings: At the 3 month follow-up, the patient was asymptomatic. The tooth was within normal limits for percussion, palpation, and probing depths, and unresponsive to cold. The radiograph showed diffuse radiopacities within the canal space. At the 6-month follow-up, responses remained the same, and the radiograph revealed significant apical development of the tooth. Evaluation at 9.5 months revealed similar clinical finding with regards to percussion, palpation, probing depths, and cold testing. The radiograph exam showed continued apical development and closure, and partial pulp canal obliteration and narrowing of the canal space. At the one-year evaluation, clinical and radiographic findings were similar.
Key points/Summary: Necrotic, immature teeth with an open apex show the potential for revascularization. The key factor is the disinfection of the root canal system. Since tissue will not grow into an empty space, a scaffold (the blood clot) is essential to aid the ingrowth of new tissue. Case selection is important, as this procedure has been shown to be successful on teeth with an apical opening of >1 mm in the mesiodistal dimension (large enough to allow for the ingrowth of vital tissue). It doesn’t really matter if the new vital tissue is truly pulp or just pulp-like, as long as there is continued development of the root walls and apex. Even if the tooth becomes necrotic in the future, conventional endodontic therapy will be much easier.
Assessment of article: Presents an alternative to treatment with calcium hydroxide or MTA…..could this really work?!