Pulp revascularization in reimplanted immature monkey incisors--predictability and the effect of antibiotic systemic prophylaxis.

In 32 monkeys 105 immature maxillary incisors were extracted and reimplanted either immediately or after 30 or 60 min wet or dry storage. Of the monkeys, 17 (group I) did not receive and 15 (group II) received prophylactic treatment with 4 mg/kg doxycycline before extraction and 2 mg/kg for 5 d after reimplantation. The observation time varied from 6 to 8 weeks. After being histologically processed, the material was evaluated with respect to the amount of vital tissue and presence of micro-organisms in the pulpal lumen. A comparison revealed no difference in the results between the groups. The results were therefore pooled and statistically analysed with respect to the significance of apical foramen width, extra-alveolar time, wet or dry storage and presence of micro-organisms in the pulpal lumen for the occurrence of complete pulp revascularization (CPR). The overall frequency of CPR was 18%. Log-linear analyses (SAS, 1985) of the material as a whole or of separate parameters consistently revealed a relationship between presence of micro-organisms and absence of CPR (P = 0.0001). A higher frequency of CPR and a lower frequency of micro-organisms (P = 0.05) was found only for the group of immediately reimplanted teeth. The presence of micro-organisms could be explained for 61 teeth. In 27 of these, blood clots containing bacteria in the apical portion of pulpal lumen indicated contamination during the extra-alveolar time, while in 34, the micro-organisms originated from plaque covered mechanical damage in the cervical part of the root surface.