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

Abstract 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.