One of the concerns of the dental surgeon in the realization of any operational act is the durability of this one. The mechanical resistance of the provisional prostheses contributes in a large part to the durability of those. The resins in general, have weak mechanical properties. The purpose of this study is to evaluate the resistance in inflection of temporary bridges reinforced with glass fibre. To remedy the weak mechanical properties of resins, we thought in this study, to reinforce them with glass fibres. For this purpose, we realized with two different resins, four groups of temporary bridges of 3 elements, including two groups reinforced fibreglass and the others not. Tests of inflection 3 points have been made on these bridges and resistance to fracture was analysed. The statistical tests showed a significant difference in four groups with better resistance for the reinforced bridges.