Effect of mesoporous silica@nano-bioactive glass complex particles on the durability of dentin bonding

This study introduced a process for synthesizing mesoporous silicon@nano-bioactive glass (nano-BAG) complex particles, and evaluated their effects on dentin bonding and remineralizing activity. Mesoporous and nonporous silica microspheres were coated with nano-BAG via a quick alkali-mediated sol-gel method at different pH values (4, 7, 9). The eight groups of particles were examined by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, nitrogen adsorption tests, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Inductively coupled plasma optical emission spectrometry (ICP-OES) was employed to record the cumulative release of Ca2+ at 7, 14, and 28 days. The ability to promote the formation of hydroxyapatite was assessed by mineralization tests. The CCK-8 cell counting kit was used to test the cytotoxicity. Microtensile bond strength (mu TBS) tests nanoleakage and were carried out to evaluate the effects of a pretreatment using mesoporous or nonporous silica microspheres coated with nano-BAG. XRD and FTIR analyses confirmed that nanoBAG coated mesoporous silica and formed a relatively ordered mesoporous structure, whereas nonporous silica did not exhibit major structural changes. In N2 adsorption tests, the specific surface area and pore volume of mesoporous silica (927.04 m2/g; 0.77 cm3/g) were much larger than those of silica (10.76 m2/g; 0.04 cm3/g). Both SEM and TEM revealed a greater homogeneity and dispersity in mesoporous silica coated with nano-BAG at pH 4. This kind of particles maintained a high level of cumulative release of Ca2+ (178.29 +/- 0.950 mg/L at 28 days), showed the strongest Ca and P signal intensity after being immersed in SBF for 28 days, and exhibited higher mu TBS values (41.56 +/- 3.110 MPa) and minimal nanoleakage. Cytotoxicity tests indicated a well-preserved cell viability in these particles. Nano-BAG-coated mesoporous silica particles, obtained at pH 4, provided a stable release of Ca2+ in body fluid, and showed a strong ability to promote the formation of hydroxyapatite. These features are beneficial for enhancing the resin-dentin bonding and reducing nanoleakage.

Automated summary

The study introduced a process for synthesizing mesoporous silicon@nano-bioactive glass complex particles and evaluated their effects on dentin bonding and remineralizing activity. The results showed that silica with mesoporous structure exhibited better performance in the prepared composite particles using a simple sol-gel method.