ABE Regenerative Endodontics 3

Question 1

Platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) have been used as alternative scaffolds in REPs. Compared to blood clot alone, what primary advantage do these platelet concentrates offer?

Accepted Answer

They contain a higher concentration of autologous growth factors (PDGF, TGF-β, VEGF)

Answer

Platelet concentrates are enriched with growth factors (PDGF, TGF-β, VEGF, IGF) that may enhance stem cell recruitment, proliferation, and differentiation compared to a simple blood clot scaffold.

Question 2

Which of the following complications is MOST specifically associated with triple antibiotic paste use in regenerative endodontics?

Accepted Answer

Crown discoloration due to minocycline

Answer

Minocycline, a component of triple antibiotic paste, chelates calcium in dentin and causes intrinsic crown discoloration, which is the most clinically recognized complication of TAP use in anterior teeth.

Question 3

In regenerative endodontics, the histologic finding of cementum-like, bone-like, or periodontal ligament-like tissue rather than true pulp-dentin complex inside the canal is BEST explained by which concept?

Accepted Answer

Ingrowth of multipotent cells from periapical tissues forming cementogenesis-type tissue

Answer

Histologic studies of REP-treated teeth commonly show cementum, bone, and PDL-like tissue rather than true pulp-dentin complex, attributed to ingrowth of mesenchymal cells from periapical/PDL origin into the fibrin scaffold.

Question 4

According to current AAE position on REPs, which of the following patient factors is considered most critical when selecting between REP and apexification with MTA?

Accepted Answer

Patient age and stage of root development (open vs nearly closed apex)

Answer

Stage of root development (apex diameter, wall thickness, root length) and patient age are paramount — REPs are best suited for immature teeth where significant root development can still occur, offering the greatest benefit over apexification.

Question 5

Which irrigant sequence is recommended by the AAE for the first appointment of a regenerative endodontic procedure?

Accepted Answer

NaOCl 1.5% → saline copious rinse → chlorhexidine 2%

Answer

The AAE protocol recommends 1.5% NaOCl (to limit cytotoxicity to SCAP), followed by copious saline rinse, then 2% chlorhexidine for broad-spectrum disinfection at the first REP appointment.

(ABE) American Board of Endodontics Practice Test

(ABE) American Board of Endodontics Practice Test

ABE Regenerative Endodontics 3