Evaluation of intracytoplasmic particles in histiocytes after endodontic therapy with a hydrophilic plastic

The presence of granules within the cytoplasm of periapical tissue histiocytes had been observed in teeth which had a root canal overfilled with a hydrophilic plastic polymer. SEM examinations revealed these granules to be barium sulfate, which was added to the polymer for radiopacity. X-ray spectra revealed strong calcium peaks in bone adjacent to the histiocytes, which showed strong barium peaks. In addition, between the histiocytes and the bone a greater concentration of calcium was seen. Because the histiocytes and not the plastic polymer contained barium sulfate, the evidence for this material's biocompatibility is greatly enhanced.