Surface Property of Composite with and Without Fluorapatite Crystals

Objectives: Investigate the surface roughness, microhardness and contact angle of three resin composites with and without fluorohydroxyapatite (FA).
Methods: Thirty composite disks were prepared from three materials, bisGMA, TMES/DNBPA and TMES/TNTATO with and without FA crystals and finished with 600-grit wet silicon carbide paper. All samples were polished using Sof-Lex™ Spiral Wheels for 15 seconds. Surface roughness measurements were made using a laser-measuring microscope. For the Microhardness test a 200g load was applied for 10s. Three indentations were produced in each sample and averaged to calculate the Vickers hardness (VHN). The static contact angle of a 3 µL droplet of water was measured on a Rame-Hart 200-F1 goniometer with 18.1 MW-cm water. Results were analyzed with and without FA, with 1-way ANOVA/ Tukey’s multiple comparison.
Results: There was no significant difference in surface roughness (SA) between bisGMA/TEGDMA + FA (0.20) and the non-FA control (0.19). A significant difference was found for TMES/DNBPA + FA (0. 38) and TMES/DNBPA (0.30) and for TMES/TNTATO+FA (0.29) and TMES/TNTATO (0.21). TMES/DNBPA and TMES/TNTATO with and without FA had significantly higher surface roughness value than biaGMA/ TEGDMA with or without FA. Microhardness showed that incorporation of FA does not cause any significant difference in surface hardness (VHN): bisGMA/TEGDMA + FA (34.2), bisGMA/TEGDMA (35.6), TMES/DNBPA + FA (19.2), TMES/DNBPA (23), TMES/TNTATO+FA (26.6) and TMES/TNTATO (23.6)
The Incorporation of the FA reduced the contact angle for the 3 composites, but was only statistically significant for bisGMA/TEGDMA + FA (57.6) and its non-FA control (45.5). All experimental composites had statistically smaller contact angles (range 29-30) than those of bisGMA/ TEGDMA with or without FA, which were 57.6 and 45.5 respectively.
Conclusions: Incorporation of FA reduced the contact angle value and increased the surface roughness of experimental resin composites, but did not affect the surface hardness.