ABE Regenerative Endodontics

Question 1

Which of the following is the PRIMARY goal of regenerative endodontic procedures (REPs) in immature permanent teeth with necrotic pulps?

Accepted Answer

Continued root development and thickening of dentinal walls

Answer

Elimination of infection followed by apexification with MTA

Answer

Obturation of the canal with gutta-percha after disinfection

Answer

Placement of a collagen barrier to allow bone fill

Question 2

According to the AAE clinical considerations for REPs, which irrigant should be used CAUTIOUSLY or avoided at full concentration in immature teeth because it can damage Hertwig's epithelial root sheath and stem cells?

Accepted Answer

Sodium hypochlorite at concentrations above 1.5%

Answer

Chlorhexidine 2%

Answer

EDTA 17%

Answer

Saline

Question 3

What is the significance of EDTA in the final irrigation step of a regenerative endodontic procedure?

Accepted Answer

It releases growth factors from dentin and promotes stem cell differentiation

Answer

It eliminates residual bacteria not killed by NaOCl

Answer

It bleaches blood clot components to improve visibility

Answer

It dissolves the triple antibiotic paste remnants

Question 4

Triple antibiotic paste (TAP) used in regenerative endodontics is classically composed of which three antibiotics?

Accepted Answer

Metronidazole, ciprofloxacin, and minocycline

Answer

Amoxicillin, metronidazole, and tetracycline

Answer

Clindamycin, ciprofloxacin, and doxycycline

Answer

Penicillin, metronidazole, and erythromycin

Question 5

Which intracanal medicament for REPs is preferred over triple antibiotic paste when tooth discoloration is a primary concern?

Accepted Answer

Double antibiotic paste (metronidazole + ciprofloxacin)

Answer

Calcium hydroxide alone

Answer

Chlorhexidine gel

Answer

Ledermix paste

Question 6

During a regenerative procedure, a blood clot is induced by over-instrumenting the periapical tissue. What is the role of the blood clot scaffold?

Accepted Answer

It serves as a fibrin scaffold for stem cell migration and tissue ingrowth

Answer

It provides a physical barrier preventing bacterial reentry

Answer

It releases calcium ions that mineralize the canal walls

Answer

It acts as an antimicrobial reservoir releasing cytokines

Question 7

Following a successful regenerative endodontic procedure, which radiographic finding would indicate a FAVORABLE outcome in an immature tooth?

Accepted Answer

Increased root length and widening of dentinal walls with periapical healing

Answer

Periapical radiolucency reducing in size with no change in root dimensions

Answer

Complete canal calcification preventing further treatment

Answer

Apex closure only without change in root length