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

They provide stronger antimicrobial activity than triple antibiotic paste

Answer

They harden immediately upon placement, eliminating the need for an MTA plug

Answer

They reduce the risk of external cervical root resorption

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

Pulp calcification

Answer

Excessive bleeding at second appointment

Answer

Failure of periapical healing

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

Complete success of the regenerative procedure

Answer

Failure of SCAP to survive the disinfection protocol

Answer

Inadequate coronal seal allowing contamination

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

Presence or absence of a sinus tract

Answer

Whether the tooth has a crown restoration

Answer

The patient's antibiotic allergy status only

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

NaOCl 6% → EDTA 17% → saline

Answer

EDTA 17% → NaOCl 1.5% → saline

Answer

Chlorhexidine 2% alone to avoid cytotoxicity

Question 6

A 10-year-old presents with a necrotic immature mandibular second premolar and allergy to all antibiotics used in TAP/DAP. What is the MOST appropriate intracanal medicament for disinfection prior to REP scaffold induction?

Accepted Answer

Calcium hydroxide paste

Answer

Formocresol

Answer

Ledermix paste

Answer

Zinc oxide eugenol

Question 7

The concept of 'revascularization' in immature necrotic teeth refers to which biologic event?

Accepted Answer

Ingrowth of new blood vessels and connective tissue into the canal space

Answer

Reestablishment of neural innervation from the periapical region

Answer

Re-differentiation of infected pulp remnants into healthy odontoblasts

Answer

Closure of the apex by cementum bridging without tissue ingrowth