Long-term water immersion of dental composites based on bioactive glass
Petra Gajski, Matej Par, Håvard Jostein Haugen, Torben Hildebrand, Kai Zheng, Aldo R. Boccaccini, Zrinka Tarle, Danijela Marović
Abstract
This study investigated the effect of copper-doped mesoporous bioactive glass nanospheres (Cu-MBGN) on water sorption, solubility and porosity of an experimental dental composite over 180 days of water immersion, comparing it to bioactive glass 45S5 (BG) or inert fillers. Composites contained 35wt% Bis-GMA/TEGDMA resin (60/40), 55wt% silanised barium-glass fillers, and 10wt% of either Cu-MBGN (10-CuBG), 45S5 bioactive glass (10-BG), or inert silica nanofillers (10-Si). Both BG composites showed a higher mass increase during water immersion than inert control (10-Si) at all measured time points (p < 0.001), ranked as 10-BG > 10-CuBG > 10-Si. After 30 days, 10-BG had the greatest mass increase (4.02 ± 0.21%), followed by a decline until 180 days, while 10-CuBG (1.67 ± 0.10%) and 10-Si (1.19 ± 0.07%) showed gradual mass increases until the end of the measurement. 10-BG displayed higher water sorption and solubility than other materials, while 10-CuBG had the highest porosity parameters. While 10-BG and 10-Si showed significant increases in both total and open porosity after water immersion, no such changes were observed for 10-CuBG. The pore characteristics of dry specimens did not affect final water sorption and solubility after 180 days of water immersion. The Cu-MBGN composite had a lower mass increase than commercial BG and met ISO 4049 standards for both water sorption and solubility.