PERIODONTAL HEALING OF EXTRACTED DOGS TEETH AIR-DRIED FOR EXTENDED PERIODS AND SOAKED IN VARIOUS MEDIA

The aim of this study was to determine the periodontal healing of repl anted dogs' teeth which, after extended extra-oral dry times, had been soaked in various media before replantation. Incisors and premolars o f beagle dogs were root canal treated, extracted and bench dried. The teeth were grouped according to dry times of 30, 45 and 60 minutes. Ea ch group of teeth was soaked in one of three media, Hank's balanced sa lt solution, ViaSpan (Belzer UW-CSS, Dupont Pharmaceuticals), or Condi tioned Medium (supernatant of confluent culture of human gingival fibr oblasts) for 30 minutes before replantation. Controls consisted of tee th extracted and replanted without drying or soaking (negative control ), and bench-dried teeth replanted without soaking in the media (posit ive control). The dogs were killed 6 months after replantation of the teeth, which were prepared for histologic evaluation. Five mu m cross- sections (every 70 mu m) of the root and surrounding tissue were evalu ated for healing/resorption according to Andreasen's criteria. The bes t healing occurred for the roots which had been immediately replanted. Healing in the positive control groups decreased with increased dry t ime. For the 30-minute dry time, groups, soaking in media had no benef icial effect on periodontal healing compared with the controls. Soakin g in ViaSpan resulted in an increased healing incidence for both the 4 5- and 60- minute bench-dried groups while soaking in the other media had no consistent beneficial effect. It appears from this study that a n avulsed tooth that has been left dry for 30 minutes should be replan ted immediately without soaking. However, teeth that have been dry for 4-5 or 60 minutes would benefit from soaking for 30 minutes in ViaSpa n.