The last centuries of the 3rd millennium in the Syrian Ǧezīra

Overview on the settlement history of the Syrian Jezirah and the Middle Euphrates Valley in the period ca. 2300-1900 BC.

La vulnérabilité des réfugiés palestiniens à la lumière de la crise syrienne

Depuis 2011, la crise syrienne et ses conséquences sur la population des quelque 500 000 réfugiés palestiniens qui y résident a fait rejaillir la vulnérabilité de cette population dans l’ensemble des pays du Moyen-Orient depuis son exode de 1948. Loin des discriminations sociales et économiques dont ils ont été les victimes dans certains pays voisins, comme au Liban, les réfugiés palestiniens se sont vus assurer en Syrie un accès sans entraves particulières à tous les secteurs de l’instruction publique ainsi qu’au marché du travail local. Mais la rébellion syrienne et la guerre civile qui s’en est suivie depuis 2011 les a ramenés à leur condition première : un peuple apatride, otage du conflit en cours, dépourvu d’une réelle protection étatique et exclu du système universel de protection des réfugiés mis en place par les Nations unies au début des années 1950.

Teeth restored using fiber-reinforced posts: in vitro fracture tests and finite element analysis

In dentistry the restoration of decayed teeth is challenging and makes great demands on both the dentist and the materials. Hence, fiber-reinforced posts have been introduced. The effects of different variables on the ultimate load on teeth restored using fiber-reinforced posts is controversial, maybe because the results are mostly based on non-standardized in vitro tests and, therefore, give inhomogeneous results. This study combines the advantages of in vitro tests and finite element analysis (FEA) to clarify the effects of ferrule height, post length and cementation technique used for restoration. Sixty-four single rooted premolars were decoronated (ferrule height 1 or 2 mm), endodontically treated and restored using fiber posts (length 2 or 7 mm), composite fillings and metal crowns (resin bonded or cemented). After thermocycling and chewing simulation the samples were loaded until fracture, recording first damage events. Using UNIANOVA to analyze recorded fracture loads, ferrule height and cementation technique were found to be significant, i.e. increased ferrule height and resin bonding of the crown resulted in higher fracture loads. Post length had no significant effect. All conventionally cemented crowns with a 1-mm ferrule height failed during artificial ageing, in contrast to resin-bonded crowns (75% survival rate). FEA confirmed these results and provided information about stress and force distribution within the restoration. Based on the findings of in vitro tests and computations we concluded that crowns, especially those with a small ferrule height, should be resin bonded. Finally, centrally positioned fiber-reinforced posts did not contribute to load transfer as long as the bond between the tooth and composite core was intact.