RESUMEN
In order to evaluate the effect of different restorative materials and techniques on the fracture resistance of tooth, forty caries free single rooted premolars were divided equally into four groups [A, Considered as control the group, without cavity preparation], [B, MOD cavity preparation, filled with amalgam alone], [C, MOD cavity preparation, filled by amalgam with bonding and adhesive], [D, MOD cavity, filled by light cured composite with bonding]. Using Instron testing machine to evaluate the fracture resistance, the results were highly significant in difference between the control group and all other groups, [B and C] and [B and D], where it was non significant between [C and D]. From these findings and under the conditions of this study, one can conclude that the normal tooth tissues [enamel, dentine] provide the best resistance to fracture, while the amalgam material provide the least, Amalgam with adhesive and, composite with bond locate in between