Surface Characteristics of Novel Dental Composite Materials Incorporating Fluorhydroxyapatite Crystals

Abstract

Objective: To investigate the hydrophobicity of composite surfaces, surface roughness and micro-hardness of three resin composites with and without fluorohydroxyapatite (FA). Material and methods: Three composite materials bisGMA, TMES/DNBPA and TMES/TNTATO with and without FA crystals were used. Five samples for each resin composite group were prepared as discs then finished using 600-grit wet silicon carbide paper for 5 seconds. All samples were polished using Sof-Lex™ Spiral Wheels in one direction for 15 seconds according to the manufacturer instructions. The hydrophobicity of composite surfaces were evaluated using a Ramé-Hart 200-F1 goniometer. Measurement of surface roughness was evaluated using the three-dimensional laser- measuring microscope. Micro-hardness test was used to determine the Vickers hardness number (VHN). Results were analyzed using 1-way ANOVA/ Tukey’s multiple comparison. Results: The Incorporation of the FA reduced the contact angle for the 3 composites, but this was statistically significant for only bisGMA/TEGDMA + glass + FA versus its non-FA control. All experimental composites had statistically smaller contact angles than those of bisGMA/ TEGDMA with or without FA. There was no significant different in surface roughness in bisGMA/TEGDMA + glass + FA versus its non-FA control, while in TMES/DNBPA and TMES/TNTATO group there was a significant increase in surface roughness value when FA was incorporated into the composites. The incorporation of the FA did not cause any significant difference in surface hardness in each composite group. Conclusion: The incorporation of FA reduced the contact angle value in all resin composites and increased the surface roughness of the experimental novel composites but not for the bisGMA/TEGDMA+ glass + FA group. Surface hardness was not affected by incorporation of FA.