الفهرس 
Materials and methodsOnly 14 pages are availabe for public view
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Abstract
Due to the magnificent importance of using proper extra oral preservation of extracted teeth, the aim of the present investigation was to study the effect of Aloe Vera, Arabic Gum and propolis as different storage media on the histological structures and ultrastructure of the pulp and periodontal ligament of experimentally avulsed and replanted teeth, and to immunohistochemically detect fibronectin and vascular endothelial growth factor in the aforementioned tissues. Materials and Methods:
Sixty adult male albino rats with an average body weight of 150±10 grams were used in this investigation. The animals were divided into five groups, 12 animals each as follows: -group I: served as negative controls (untreated). group II: served as positive controls. -group III, IV and V: served as experimental groups.
The animals were caged in wire top cages six animals per cage; they were supplied natural diet and drinking tap water adlibitum throughout the whole experimental period.
The animals of groups II, III, IV, and V were anaesthetized using thiopental sodium as intraperitoneal injection of 40 mg/kg body weight. Their lower left central incisors were luxated using cement spatula then extracted using Bayonet forceps. The extracted teeth of group II animals were immediately reimplanted in their sockets. The extracted teeth of groups III, IV, V were stored in Aloe Vera gel, gummy exudates of Arabic Gum and propolis extract respectively for 15 minutes then reimplanted in their sockets.
The reimplanted teeth were splinted with composite on their lingual sides. All the animals received a single intramuscular dose of 20.000 IU of penicillin after tooth reimplantion.
Six animals of each group were sacrificed by cervical dislocation after one week while the rest of the animals were sacrificed by the same way after three weeks of the beginning of the experiment. The mandible of each rat was dissected out, separated. The left halves were fixed in 3% phosphate buffered glutaraldehyde for 4 hours , washed in the buffer for 24 hours at 4°c then the specimens were decalcified in 10% ethylene diamine tetra acetic acid( EDTA)PH 7-7.4. After complete decalcification, jaw specimens were washed in the phosphate buffer. Half of the specimens were prepared for light microscopic examination. They were dehydrated in alcohol, cleared in xylene, embedded in paraffin, sectioned and subjected to: 1- Hematoxylin and eosin stain (H&E): for histological examination of the pulp and periodontal ligament.
2- Masson’s trichrome stain: for collagen demonstration.
3- Immunohistochemical stains: for detection of fibronectin and vascular endothelial growth factor.
Very small pieces (1 mm3) of the other half of the specimens were cut after complete decalcification using very sharp blade within the phosphate buffer from the corresponding sites to be examined with transmission electron microscope for ultra-structural examination of the periodontal ligament at cervical and middle regions of the roots as well as the dental pulp which was easily withdrawn from the incisors after complete decalcification. Specimens were then washed in freshly prepared phosphate buffer PH7, post fixed in 1% buffered osmium tetroxide, washed, dehydrated in ascending grades of ethanol and then embedded in epoxy resin .ultra-thin sections were cut and stained with uranyl acetate followed by lead citrate and examined with transmission electron microscope.