In order to rebuild the decayed teeth it’s necessary to re-establish the elastic properties of lost dental tissues, replacing them with restorative materials. A not corrected reconstructive method in the dental implant could reduce the mechanical performance causing its progressive premature failure. In this work composite materials, based on quartz fibers posts and adhesive resins, were employed with the aim to restore damaged teeth. Two groups of extracted teeth were rebuilt with two different techniques. In the first group of samples (A) the fiber quartz post and the adhesive resins were simply located into the dental implant and then cured by a light source. In the second group (B) the post and the resin were in situ preformed and then photo-cured; the pre-formed post was then cemented to the tooth with the same procedure of the group A. The two different types of dental restorations were mechanically characterized with a pull-out test with an universal testing machine (Lloyd LR10K). The experimental results showed that the B group samples have an higher mechanical strength than the A group samples, evidencing a better interface adhesion between post– adhesive–tooth. The difference of means of pull out stress data was statistically confirmed by the ANOVA method.