What is the most likely cause of this radiopacity?

Pulp stones (denticles) are discrete, well-defined calcified masses that form within the pulp chamber or root canal. They appear as round/oval radiopacities inside the pulp outline. They are common in older or chronically irritated pulps, patients with pulpal inflammation, dentinogenesis imperfecta, or Ehlers-Danlos syndrome. Because the chart confirms no restoration exists, retained material (A) is ruled out. Hypercalcification (B) is a diffuse enamel change. Pulp stones fit the radiographic picture exactly.