Remineralizing potential of dental composites containing silanized silica-hydroxyapatite (Si-HAp) nanoporous particles charged with sodium fluoride (NaF).

Objectives: To synthesize and evaluate the enamel remineralizing potential of dental composites containing silanized silica-hydroxyapatite (Si-HAp) nanoporous particles charged with sodium fluoride (NaF).

Methods: Si-HAp particles were synthesized using a solid-state method. Dental composites were prepared by incorporating 70 wt.% of Si-HAp particles into a 70/30 wt.% Bis-GMA/TEGDMA organic matrix. Four dental composites were produced: SilF, Sil, F, and NT (nontreated). For SilF and F, Si-HAp particles were previously treated with 10% NaF (F). Afterwards, SilF and Sil composites had their particles silanized (Sil) with α-methacryloxypropyl-1-trimethoxysilane (α-MPS). The remineralizing potential was evaluated in caries-like enamel lesions induced byS. mutans biofilm for seven days and after pH-cycling for fifteen days using X-ray microtomography (micro-CT). Z350 was used as a commercial control for remineralizing potential evaluation Degree of conversion (DC%), flexural strength (FS), and Knoop hardness (KHN) were characterized. Data were analyzed using one-way ANOVA and Tukey's HSD post-hoc test (α = 0.05).

Results: F presented the highest enamel remineralizing potential, followed by SilF. Alternatively, Sil and NT were not capable of totally recovering the enamel mineral loss. NT showed the highest DC%, followed by Sil, F, and SilF. Sil and NT showed the highest FS when compared to SilF and F. No statistical significance in KHN was found among the composites.

Conclusions: Dental composites with Si-HAp nanoporous particles charged with NaF presented a remineralizing potential for human enamel. However, this ability underwent a subtle reduction after particle silanization.

Clinical Significance: Si-HAp nanoporous particles charged with NaF may be an alternative for producing dental composites with an improved remineralizing potential for enamel affected by caries.