الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Fiber reinforced posts have been widely used for restoration of endodonticaly treated teeth. Similarity in elastic behavior between fiber posts and the residual root dentin, decreases the rate of root fracture, restoration of an endodontically treated teeth by fiber post and core becomes a common approach nowadays, however clinicians face a lot of challenges regarding the bond strength and the radiopacity especially when sterilization of such posts is essential.
Due to a number of reasons the dentist often has to change his initial choice where disinfection and sterilization of the post is necessary for later re-use. Proper and efficient sterilization of materials between each patient is a legal obligation, an ethical responsibility and an essential measure in the fight against cross-infection.
Among the most widely used sterilization techniques, exposure to gamma rays is the most commonly used technique to sterilize pharmaceuticals and medical devices because of its high penetrating ability, uniform and time dependent delivery of the required doses without any toxic residue. On the other hand, autoclave sterilization is the most popular method of sterilization and is considered as a gold standard for sterilization procedures.
However clinicians face a lot of challenges regarding the bond strength and the radiopacity especially when sterilization of such posts is essential, therefore this study was conducted focusing on gamma and autoclave sterilization and their effect on Radiopacity and bond strength of two types of fiber post.
In this study forty single rooted teeth were used. Teeth were decoronated at the cementoenamel junction, then endodonticaly treated. Following post space preparation, the roots were divided into two groups according to the type of the post used, group 1 Easypost Dentsply (silanated), group 2 Dentoclic Itena (non-silanated), each group was divided into two subgroups according to the method of sterilization, gamma and autoclave sterilization.
Fiber posts were radiographed before and after different types of sterilization for radiopacity measurement, then sterilized by gamma radiation at 25 KGy and autoclaved at 1340 C then cemented using self adhesive resin cement (Gcem).
The roots were sectioned using Isomet into three sections (coronal, middle, apical), then bond strength was evaluated using push out test while radiopacity was evaluated using Digora software. Results showed that : No significant difference on radiopacity by gamma or autoclave sterilization ,the regional bond strength values were reduced significantly in apical post space in the Easypost and Dentoclic fiber posts, no significant difference between gamma and autoclave sterilization on regional bond strength values of the Easypost and Dentoclic fiber posts, Easyposts groups showed the highest push out bond strength at the coronal and middle sections than that of Dentoclic groups in Gamma and Autoclave sterilization.