ABSTRACT
Objective: Although computer technologies are now widely used in medicine, little is known about its use among medical students in Iran
The aim of this study was to determine the competence and access to computer and internet among the medical students
Methods: In this descriptive study, medical students of Shahid Sadoughi University of Medical Science, Yazd, Iran from the fifth years were asked to answer a questionnaire during a time-tabled lecture slot
The chi-square test was used to compare the frequency of computer and internet use between the two genders, and the level of statistical significance for all test was set at 0.05
Results: All the students have a personal computer and internet access
There were no statistically significant differences between men and women for the computer and internet access, use wireless device to access internet, having laptop and e-mail address and the difficulties encountered using internet
The main reason for less utilization of internet was slow speed of data transfer
Conclusions: Because of the wide range of computer skills and internet information among medical students in our institution, a single computer and internet course for all students would not be useful nor would it be accepted
ABSTRACT
Many studies have been performed to evaluate the stress distribution around endodontic posts; those which compared posts composed of different materials are rare. The aim of this study was to compare stresses induced in dentin by three structurally different posts using photoelasticity method. Nine blocks of PSM-5 Photoelastic material with 45x45x10 mm dimension were prepared. In each block, a canal 9 mm in length and 0.8 mm in width was drilled. Blocks were divided into 3 groups of three each. In the first group, the canals were prepared for insertion of Fiber Post with 1.25 mm width. In the second group, the canals were prepared for insertion of ParaPost with 1.25 mm width and the canals in the third group were prepared for casting post similar to the above samples. Casting Post pattern was made by Duralay resin and casted by Ni-Cr alloy. All posts were cemented in canals with Panavia cement. The stresses were evaluated in the polariscope under three different conditions: 1] without load, 2] with 135 N vertical load, and 3] with 90 N oblique load [26° inclination to post long axis]. The fringe orders in the cervical, middle and apical regions of the posts were evaluated and compared with each other. Application of the vertical load induced a high stress concentration [FO=4] in the apical region of the ParaPost, while lower stress was observed in the middle [FO=2] and cervical region[FO=2+]. Fiber Post and Casting Post showed even stress distribution [FO=2+]. High stress concentration was detected with the application of oblique force in the cervical region of ParaPost [FO=5] and Casting Post [FO=3+]. Fiber Posts fractured before reaching 90-N loading force. The stress distribution around Fiber Post and Casting Post were constant in comparison with ParaPost. Fiber Post with 1.25 mm width was not recommended in situations with high oblique Stresses