ABE Regenerative Endodontics 2

Question 1

Stem cells of the apical papilla (SCAP) are considered the PRIMARY source of cells for root development during regenerative endodontic procedures. Where do SCAP reside?

Accepted Answer

In the loose connective tissue apical to the root apex in immature teeth

Answer

Within the periodontal ligament at the furcation

Answer

Along the cervical third of the root canal wall

Answer

Within the pulp chamber of mature teeth

Question 2

Which of the following correctly describes a KEY difference between apexification and regenerative endodontic procedures for treating necrotic immature teeth?

Accepted Answer

Apexification creates an apical barrier without continued root development; REPs aim for continued root maturation

Answer

Apexification uses a scaffold; REPs use MTA plug

Answer

REPs are indicated only in teeth with closed apices

Answer

Apexification is preferred when apex diameter is less than 1 mm

Question 3

MTA (Mineral Trioxide Aggregate) is placed as a cervical plug in regenerative endodontic procedures primarily to:

Accepted Answer

Seal the coronal aspect over the scaffold and prevent bacterial leakage

Answer

Stimulate angiogenesis in the blood clot scaffold

Answer

Provide an antibacterial effect throughout the canal

Answer

Encourage differentiation of SCAP into odontoblasts

Question 4

In the AAE-recommended REP protocol, the second appointment (scaffold induction) should ideally be scheduled at least how long after the first appointment?

Accepted Answer

1–4 weeks

Answer

1–2 days

Answer

3–6 months

Answer

Immediately at the same appointment

Question 5

Which growth factor found abundantly in dentin matrix plays a critical role in odontoblast differentiation and is released by EDTA conditioning during REPs?

Accepted Answer

Transforming growth factor beta-1 (TGF-β1)

Answer

Vascular endothelial growth factor (VEGF)

Answer

Platelet-derived growth factor (PDGF-BB)

Answer

Fibroblast growth factor-23 (FGF-23)

Question 6

A patient presents with an immature maxillary central incisor that suffered a luxation injury 18 months ago. The tooth is asymptomatic but shows no response to EPT and a periapical radiolucency is present. What is the MOST appropriate initial management?

Accepted Answer

Regenerative endodontic procedure (REP)

Answer

Immediate MTA apexification

Answer

Extraction and implant planning

Answer

Calcium hydroxide dressing changed every 3 months for 2 years

Question 7

Which of the following is classified as an outcome category for REPs by the AAE as a 'Level 3' or best outcome?

Accepted Answer

Increased root length AND wall thickness AND positive response to pulp testing

Answer

Resolution of periapical pathology only

Answer

Increased root length OR wall thickness but not both

Answer

Canal calcification with no periapical lesion