Pulp Revascularization of a Necrotic, Infected, Immature, Permanent Tooth

Department of Pediatric Dentistry
Resident’s Name:Murphy Program: Lutheran Medical Center - Providence
Article title:Case Report: Pulp Revascularization of a Necrotic, Infected, Immature, Permanent Tooth
Author(s): Thibodeau DMD MS, Blayne
Journal: Ped. Dent.
Year. Volume (number). Page #’s: 2009. v31 N2. 145-149
Major topic: Pulp Revasc.
Minor topic(s): Methods/new treatment options
Main Purpose: Present the case of a 9 yo pt. Wherein revasc. Of the infected, necrotic pulp space of an immature permanent maxillary central incisor was induced in vivo by stimulation of a blood clot from the periapical tissues into the canal space

Overview of method of research:
9 yo Caucasian male was seen in the ER clinic at UNC School of Dentistry for evaluation of a maxillary anterior swelling assoc. with #8. Dental hx revealed that the pt. Had suffered dental trauma approx. 2 years ago. There was an Ellis III fracture, which was treated with a cvek pulpotomy 2 days after the incident. RDI was NOT used during this procedure due to the tooths partial eruption. At the current ER visit, the tooth tested necrotic to cold, WNL to percussion, palpation, and probing depths. #8 was diagnosed w/ a necrotic pulp and PA abscess. It was initially treated by I and D.
At the next visit, the tooth was disinfected w/ betadine, anesthesized, and isolated w/ RDI. Pulp was accessed, irrigated copiously w/ 1.25% NaOCl, and dried w/ paper points. A creamy past of equal portions of metronidazole, ciprofloxacin, and ceclor mixed w/ sterile water was put in the canal by lentulo spiral. The paste was tapped down by the blunt ends of paper points. A cotton pellet was placed, and IRM was used to restore the prep. Notice that no instrumentation was done.
At the 11 week FU appt. the pt. Was asymptomatic. Again, under LA the tooth was disinfected w/ betadine, and RDI was sued. The paste was irrigated away w/ NaOCl and 10 ml of sterile water. Again, no instrumentation of the canal space was done. The apical tissue was stimulated with an endo file to induce bleeding. 15 minutes was allowed for a blood clot to form that approximated the CEJ. MTA was mixed w/ sterile water and was placed over the clot. A cotton pellet was placed over the MTA. After one hour of letting the MTA set, the cotton pellet was removed, and a bonded composite was used to restore the tooth.
At the 3 months FU, pulp test was WNL for all but cold, to which there was no response. The pt. Was asymptomatic. Radiographically there was diffuse radiopacities w/I the canal space. At the 6 and 9 ½ month FU, the was the same pulp responses as the3 month FU, and there were more and more radiopacities at each FU visit.
At the 1 year appt., the tooth tested the same, however radiographically there was normal PA structure w/ cont. root development and calc. Of the canal space.
at the 16 month FU, the tooth cont. to develop nicely. 41 months after the blood clot induction, the pt is in full ortho tx, and completely asymptomatic.

Findings:
Traditional techniques of chemomechanical instrumentation/disinfection of the root canal used in mature permanent teeth are limited in immature permanent teeth due to anatomy. The open apex is difficult to seal b/c the is no apical stop. Also, arrested development of the dentinal walls from necrosis leaves the tooth weak, and susceptible to fracture. Traditional tx included long term application of CaOH2, However, Andreason has showed that this may lead to even weaker walls, making a fracture easier. Under the new treatment philosophy, the necrotic pulp acts as a scaffold for the in growth of new tissue. The KEY FACTOR for success is proper disinfection of the root canal system. This is theorized to be essential to create the environment in which revasc. Can occur. Various combinations of topical antibiotics such as metro, cirpo, and ceclor have been used to disfinect the carious dentitn and necrotic roots.
A bacteria free canal is necessary for tissue regeneration, however tissue cannot grow into a dead space. Thus, the idea of using the disinfected necrotic tissue as a scaffold was introduced. The blood clot that is induced to form over the tissue consists of many growth and differential factors, important in wound healing, and it contains cross linked fibrin, serving as a pathway for the migration of cells.

Key points/Summary:
The case report illustrates the potential for revasc. Of a necrotic, infected tooth. Even if the tissue undergoes necrosis and subsequent infection at a later time, the prognosis for conventional RCT is much better than had it been with the open apex. If progressive calcification continues to proliferate to the point of canal obliteration, vitality will most likely be maintained. It’s important to remember that case selection is important with this treatment protocol. It is encouraged for teeth with pulpal necrosis with an immature apex that is open >1mm MD radiographically. Materials for the procedure can be obtained and mixed at any pharmacy. If revasc is not successful, traditional tx should be completed.

Assessment of Article:
Very interesting article to read. Took a different approach than the conventional treatment/wisdom.. I’d like to try it.