Figure 1.

(a) Example of raw data obtained during tensile tests. In some cases (dotted curve) the specimen was partly slipping between the clamps, especially at the beginning of pulling; while this did not affect the maximum force measured on breaking, we discarded experiments with significant slipping; (b) typical optical images (not at same scale) of side view of the tooth composite specimens used (top), and broken interface in cross section (bottom); (c) bar plot (means ± one standard deviation) of the adhesion strength for all the three composites considered. The asterisk represents statistically significant differences, (*: p < 0.05).