Fawzy A.Darweesh¹, Ahmed R.Zaher², Adel E. Zaghlool³, Mohamed E.Helal⁴, Heba M. El-Sabaa^{5 1}Senior teaching Assistant, Oral Biology, Faculty of Dentistry, Mansoura University,Egypt. ² Professor of Oral Biology, Faculty of Dentistry, Mansoura University, Egypt. ³Professor of surgery, Anesethiology, Faculty of Veterinary, Mansoura University, Egypt. ⁴Professor of Oral Biology, Faculty of Dentistry, Mansoura University, Egypt. ⁵Associate Professor of Oral Biology, Faculty of Dentistry, Mansoura University, Egypt. Abstract: Objectives: Management of both avulsions and intrusions is controversial: avulsions present the dilemma of whether or not to replant. Replantation of an avulsed tooth is an invasive procedure that requires informed consent of the patient or parent and the cooperation of the patient. Propolis may be a better storage medium in terms of maintaining PDL cell viability after avulsion, storage and re-implantation. Methods: Thirty nine healthy mixed-breed female dogs aged from six to 11 months and had fully erupted incisors.  All dogs divided into 3 dogs as Negative Control group kept without any surgical interference sacrificed at 21, 30 and 45 days from day zero of the experiment and Positive Control group:12 dogs were subjected to surgical extraction to the upper left second incisor followed by immediate replantation. Group I (dry air group) Extracted left second incisors of this group were assigned to be left in dry air then replanted 60 minutes after extraction, Group II (propolis group), The same protocol of group I but with storage in propolis Results: Histological examination by using H&E stain in group I dry air storage showing areas of destructed fibers of periodontal ligament with marked dissociation of PDL fibers in relation with cementum and alveolar bone, Large areas of root and alveolar bone resorptionwere mainly observed while in control groups or in group II propolis storage, minimal histological changes were observed. The histochemical examination by using Masson's Trichrome Stain and Mercuric-bromophenol blue stain in group I dry air storage showing weak to moderate positive reaction of PDL fibers while in control groups or in group II propolis storage, strong positive reactions were observed. The radiographic examination of group I dry air storage showed increased periodontal ligament space with loss of lamina Dura and extreme decrease of the level of the alveolar bone crest, in control groups or in group II propolis storage illustrated minimal radiological changes with decrease of the level of the alveolar bone crest. Conclusions: Propolis is a good storage medium for avulsed teeth before replantation. Storage of the avulsed tooth in dry air decrease markedly success rate of tooth replantation. Keywords:Propolis, periodontal ligament, storage medium.