Article Title: Considerations for Regeneration Rrocedures
Author: Alan S. Law, DDS, PhD
Journal/Date: Pediatric Dentistry, Vol. 35 No. 2 March/April 2013
Major Topic: Review the literature related to regenerative endodontic procedures.
Main Purpose: Discuss consideration for Regenerative endodontic procedures and they can increase the prognosis for immature teeth with necrotic pulp tissue.
Introduction: Dental trauma in an immature tooth can lead to many problems. Pulp necrosis and incomplete root formation make endodontic therapy difficult, which can lead to premature loss of permanent teeth and a compromised dentition. Blunderbuss apices make immature teeth harder to clean, shape, and obturate; not to mention thin root walls are easy to fracture. The concept of revitalizing root canal tissue has been around since the 1970’s. Two recent studies have created interest in this concept. Both case reports showed 3 important principles of regenerative endodontics:
1. Elimination of bacteria from the canal system
2. Creation of scaffold for the ingrowth of new tissue
3. Prevention of reinfection by creating a bacteria-tight seal
There are 3 terms that are used to describe new living tissue into the canal space.
· Revascularization – re-establishment of the vascular supply to existing pulp in immature permanent teeth.
· Revitalization - ingrowth of tissue that may not resemble of the original lost tissue
· Regeneration – replacement of damages structures, including dentin and root structures, as well as the pulp-dentin complex
Studies that have been able to look at the histology of the regenerative tissue have found loose connective tissue that is similar to that of pulpal tissue. Although this may not be representative of all teeth.
In the 2000 there have been several case studies that address regeneration of the pulpal tissue in a necrotic, immature permanent tooth.
1. Younger patients (6-18 y/o)
2. Permanent teeth with immature apices.
3. Minimal to no canal instrumentation
4. Placement of an intercnal medicament
5. Placement of a bacteria-tight seal at the completion of the tretment
1. Type and concentration of irrigants (1.25-5.25% NaOCl with and without the use of Peridex or 3% hydrogen peroxide
2. Type and concentration of the intercanal medicaments (TAP, double antibiotic paste, calcium hydroxide)
3. Number of appointment and the length of time in between appointments (none to 3 months)
4. Creation of a blood clot verses the use of another scaffolding type (PRP – platelet-rich plasma; AFM – autologous fibrin matrix)
5. Type of pulp space barrier
6. Final restoration
American Association of Endondontists (AAE) Regenerative Endodontics Committee created a document that gave the most current recommendations and are summarized here.
A few clarifying details:
· Necrotic pulp -etiology does not matter (trauma, dental anomalies, decay)
· Pulp space barrier is needed so no post space
· Stem cells – aka immature apices have increase source compared to mature apices
· Antibiotics – must question parents for allergies
· Make sure to mention alternative treatments if regenerative therapy fails
· Chlorhexidine is also cytotoxic to stem cells
· Diluted concentrations of antibiotics because of detrimental effects on stem cells
· TAP can cause discoloring: eliminate minocycline, seal coronal dentin with dentin bonding agent, composte or calcium hydroxide paste
· LA with out vasoconstrictor is recommended so that bleeding can be induced with extraneous influences
· Draw backs to use of PRP and AFM for a scaffolding, is an additional blood draw
Described out comes of REP in the literature:
Andreasen and Bakland – 1200 traumatized teeth; 320 autotransplanted premolars:
1. Revascularization of the pulp with accelerated dentin formation leading to pulp canal obliteration
2. Ingrowth of cementum and periodontal ligament
3. Ingrowth of cementum, PDL, bone
4. Ingrowth of bond and bone marrow
Chen et al. – 20 teeth
1. Increased thickening of the canal walls and continued root maturation
2. No significant continuation of root development with the root apex becoming blunt and closed
3. Continued root development with the apical foramen remaining open
4. Severe calcification (obliteration) of the canal space
5. A hard-tissue barrier formed in the canal between the coronal MTA plug and the root apex
Discussion: good overview of REP, must keep up-to-date, quickly evolving field