Effect of tetracycline and SnF2 on root resorption in replanted incisors in dogs

The present study was made to assess the effect of applying SnF2, tetracycline, or both, to root surfaces of extracted teeth prior to replantation. In five young adult beagles, a total of 18 mandibular incisors were extracted, bench dried for 45 min, and reimplanted in their respective sockets either after no further treatment or following treatment with 1% doxycycline HCl for 5 min, 1% SnF2 for 5 min, or 1% SnF2 followed by 1% doxycycline HCl. After 4 wk of healing, the relative frequency of root resorption (surface resorption, inflammatory resorption and replacement resorption) was approximately 27% of the root surface in bench-dried as well as in doxycycline-treated specimens. By contrast, SnF2-treated and SnF2 + doxycycline-treated teeth showed less than 1% resorption. In the latter two specimen groups an inflammatory reaction in the periodontal ligament without resorption occurred with a frequency of 38.3% and 11.1%, respectively. The results indicate that application of SnF2 to the root surface prior to replantation effectively reduces resorptive processes during the first postoperative weeks. By subsequently treating the root surface with tetracycline, the adverse effect of SnF2 on periodontal connective tissue repair may be reduced.