Secondary dentin deposition in dens evaginatus: report of a case.

An unusual case of dens evaginatus in a 22-year-old man is reported. The involved tooth was the right upper second premolar which appeared to have been segregated into coronal and apical segments during the disease process. Although abscess formation was noted in the coronal portion, continuing secondary dentin deposition was found over the displaced apical segment. The pathogenesis of this unusual dentinal bridge formation is proposed based on the microscopic and radiographic findings.