engleski

Development of experimental bioactive composites with reduced water sorption

Aim: To address the issue of high water sorption in experimental remineralizing composites by adjusting the resin hydrophilicity and changing the type of bioactive fillers. Materials and methods: Two series of light-curable experimental composites were prepared. The series denoted “ACP” was based on a Bis-EMA/TEGDMA/HEMA resin and amorphous calcium phosphate (ACP) fillers. The series denoted “BG” was based on a Bis-GMA/TEGDMA resin and bioactive glass 45S5 fillers. Variable amounts of bioactive and reinforcing fillers (barium glass and silica) were admixed to the resinous component in a dual asymmetric centrifugal mixer. Water sorption was assessed by the gravimetric method at regular time intervals, while the precipitation of hydroxyapatite was investigated by Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Results: Both ACP- and BG-series showed bioactivity in an aqueous medium, demonstrated by the release of calcium/phosphate ions and the precipitation of hydroxyapatite. The ACP-series was highly hydrophilic, with water sorption ranging from 25-32 wt% for composites and 46 wt% for the neat resin. The BG-series was notably less hydrophilic, with water sorption values of 2-7 wt% for composites and 4 wt% for the neat resin. The pattern of weight change differed considerably between the two series: the weight vs. time curves for the ACP-series plateaued 14 days after the immersion, while those of the BGseries started to decline after 3-28 days. This indicates more extensive and prolonged ion release of the BG-series. Conclusion: Vast differences in hydrophilicity did not impair the ion-releasing ability of the experimental remineralizing composites.

bioactive composites, water sorption

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