Which of the following is NOT listed as a common indication for nonsurgical retreatment?

• A. Persistent symptoms
• B. Recurrent sinus tract
• C. Significant coronal leakage
• D. Apical root resorption

Answer: (D)

Nonsurgical retreatment is pursued when reinfection originates from within the root canal system or from a compromised coronal seal, so the tooth can be disinfected and properly sealed again. Persistent symptoms indicate that bacteria remain despite initial treatment, making retreatment the logical next step to eradicate the infection. A recurrent sinus tract shows ongoing drainage from periapical infection, signaling that the canal contents still harbor pathogens that retreatment aims to remove. Significant coronal leakage compromises the seal and allows oral bacteria to re-enter the canal system, again making retreatment appropriate to re-establish a clean, well-sealed canal obturation.

Apical root resorption, while it can accompany endodontic disease, is not a typical indication for nonsurgical retreatment. It often reflects a pathologic process at the apex that may require different management, such as surgical intervention or other options, rather than simply retreating the canal filling.