Australian Dental Council (ADC) Practice Test

Periapical surgery is typically indicated when there are complications or failures from prior endodontic treatments, especially when the risk of further damage exists. The correct choice emphasizes the potential risk of root fracture during endodontic re-treatment. If a dentist performs an endodontic treatment on a tooth with an existing root canal filling, the instruments used and the manipulation of the tooth structure can lead to fissures or fractures, which may compromise the tooth further.

This condition calls for periapical surgery not only to address the immediate concern of tooth integrity but also to prevent further complications that could arise from a damaged root.

The other options discuss scenarios that may indicate different aspects of dental treatment or complications, but they do not directly pinpoint the immediate surgical intervention needed due to the potential fracture risk. The focus here is on the implications of re-treatment and the direct anatomical and structural considerations that inform the need for surgical intervention.