Niobium Core-Shell Particles in the Development of Remineralizing Resin Adhesives.

Objectives: This study aimed to develop an experimental resin adhesive containing core-shell niobium (Nb@SiO2) particles to promote mineral deposition for dental adhesion.
Methods: Nb@SiO2 particles were synthesized using a modified Stöber method. These particles were characterized for morphology, chemical composition, particle size, and surface area. An adhesive resin was formulated with BisGMA (66.6wt%) and HEMA (33.3wt%). To create the experimental groups, the particles were incorporated into the base adhesive at concentrations of 1wt%, 2.5wt%, and 5wt%. The unfilled adhesive served as the control group. The adhesives were characterized by degree of conversion, softening in solvent, cytotoxicity, mineral deposition analysis, microtensile bond strength and ultimate tensile strength.
Results: The particles exhibited regular spherical morphology, characteristic chemical peaks, an average diameter of 630nm (± 61.303), and an average surface area of 36.282m2. All groups presented a degree of conversion over 50%. The 1wt% Nb@SiO2- containing adhesive showed no statistical difference compared to the control group in this test. The control group exhibited lower softening in solvent compared to the Nb@SiO2 -added groups. There was no reduction in cell viability for the experimental groups compared to the control group (p < 0.05). All experimental groups containing Nb@SiO2 showed phosphate deposition after 7, 14, and 28 days, and this deposition increased over time.
Conclusions: The addition of up to 5% Nb@SiO2 in adhesives promoted mineral deposition ability, while maintaining the physicochemical properties of the material.