Australian Dental Council (ADC) Practice Test

In the context of avulsion replantation, the common cause of failure is often related to external resorptive defects. When a tooth is avulsed and then replanted, several biological factors come into play that can affect the success of the procedure. External resorption, which is the loss of the tooth's root structure due to the activity of osteoclasts, can lead to a gradual breakdown of the tooth's integrity. This condition can be exacerbated by factors such as prolonged extraoral dry time, contamination during the avulsion process, or a lack of vital pulp tissue, which is essential for healing.

The occurrence of external resorption can result in instability of the reimplanted tooth, affecting its adherence to the surrounding bone and periodontal tissues. This ultimately compromises the long-term prognosis of the replantation procedure, leading to failure.

While other factors like coronal pulp necrosis, the patient's age, and improper storage of the avulsed tooth can significantly impact the outcome of avulsion replantation, the process of external resorption is a direct biological phenomenon that manifests as a complication specifically related to how the tooth and surrounding tissues respond to injury and reimplantation.