Microhardness of composites has been related with degree of conversion, as differences in the organic matrix composition determine changes in polymerization dynamics. Post-cure
heating is a process which the composite is submitted in order to enhance its properties, resulting in better restorations. This study evaluated the influence of the post-cure heating on the direct composite microhardness. Samples were made with Charisma and light cured with halogen lamp during 20 seconds. After, samples were submitted to one of the following
post-cure methods: autoclave, microwave oven and conventional oven. It was created two controls: a negative control, that consisted of the use of the resin Charisma only light cured; and positive control group, formed by the indirect composite Targis. The Knoop microhardness was obtained after one week of storage and the results submitted to statistical analysis. The three proposed methods determined an increase on the microhardness of the direct composite
when compared to the negative control (p < 0,05), not differing of the indirect restoring composite (p > 0,05). This study presents scientific evidence that post-cure heating enhances microhardness of restorative composite resins, suggesting that all others properties may be also enhanced.

UNITERMS: composite; polymerization; heat; microhardness.