Long-term histologic changes in the dental pulp after posterior segmental osteotomies.

OBJECTIVE

The purpose of this study was to examine pulp tissue for 18 months after segmental osteotomy in nonhuman primates.

STUDY DESIGN

In this long-term experimental study, subapical, posterior, maxillary, and mandibular osteotomies were done in 26 baboons (Papio ursinus). Baboons were killed humanely immediately after operation and at 3, 6, 12, and 18 months, when tissues were perfusion-fixed. Longitudinal step-serial sections of dental pulps were examined.

RESULTS

There was a loss of the odontoblast layer as early as 3 months after surgery. Inflammatory cell infiltrate was most marked in the early postoperative stages, and the formation of osteodentin and secondary dentin was evident after 6 months. Foci of necrosis were present in the 3-month and 6-month groups but were replaced by pulp fibrosis in the 12-month and 18-month groups. All these changes were more frequent in experimental than control teeth.

CONCLUSIONS

The histologic changes seen should not affect the prognosis of teeth in subapical osteotomy segments if clinicians are careful not to damage root apices and do regular, careful, clinical, and radiographic follow-up examinations. Because many pulps healed spontaneously in the study teeth, endodontic treatment should be delayed until it is clearly needed.