This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
[{'content': 'Replacement resorption is characterized by: \nSelect and explain. \nA. Lamina dura is lost, B. Moth eaten appearance, C. Metallic sound on percussion, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Complications\nWhen a tooth is avulsed, the attachment apparatus of the\xa0tooth is damaged and blood vessels at the apex are severed. If the cemental layer is intact, it acts as a physical\xa0barrier that prevents the toxins from the pulp from reaching\xa0the periodontal ligament. After avulsion, if the protective cemental layer is damaged, the insulating quality\xa0is lost. If the pulp becomes infected, the toxins can now\xa0pass through the dentinal tubules and stimulate inflammatory root resorption. The denuded root surface\xa0is resorbed by multi-nucleated giant cells and is continued\xa0until the stimulus is removed. Radiographically, inflammatory resorption is observed as progressive radiolucent\xa0areas. \nOn the other hand, ankylosis can occur. Ankylosis\xa0is termed as replacement resorption. Radiographically, a\xa0traceable lamina dura is lost and a moth-eaten appearance\xa0results. Clinically, lack of mobility and metallic sound to percussion of the tooth is pathognomonic.', 'role': 'assistant'}]