A 16-year-old reports pain around tooth 4.6, which responds to vitality testing. A radiograph shows a well-defined radiopaque mass fused to the distal root, surrounded by a thin radiolucent rim. What is the most likely diagnosis?

Explanations

• Cementoblastoma is a benign tumour of young people, most often on a mandibular first molar, appearing as a radiopaque mass fused to the root with a radiolucent rim, often with pain. Condensing osteitis is associated with a nonvital or inflamed pulp and has no radiolucent rim or root fusion.

  Source: Neville et al., Oral and Maxillofacial Pathology — oneguy