Chemical, structural and cytotoxicity characterisation of experimental fluoride-doped calcium phosphates as promising remineralising materials for dental applications

Objectives: This study aimed at evaluating the cytotoxicity, chemical and structural properties of experimental fluoride-doped calcium-phosphates as potential remineralising materials for dental applications.Methods: Experimental calcium phosphates were formulated using beta-tricalcium phosphate, monocalcium phosphate monohydrate, calcium hydroxide, and different concentrations of calcium/sodium fluoride salts [(5 wt%: VSG5F), (10 wt%: VSG10F), (20 wt%: VSG20F)]. A fluoride-free calcium phosphate (VSG) was used as control. Each tested material was immersed in simulated body fluid (SBF), (24 h, 15 and 30 days) to assess their ability to crystallise into apatite-like. Cumulative fluoride release was assayed up to 45 days. Moreover, each powder was placed into a medium containing human dental pulp stem cells (200 mg/mL) and their cytotoxicity was analysed using the 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay (24 h, 48 h and 72 h incubation). These latter results were statistically analysed by ANOVA and Tukey's test (alpha = 0.05).Results: All the experimental VSG-F materials produced fluoride-containing apatite-like crystals after SBF im-mersion. VSG20F presented prolonged release of fluoride ions into the storage media (45d). VSG, VSG10F and VSG20F showed a significant cytotoxicity at dilution of 1:1, while at 1:5, only VSG and VSG20F demonstrated a reduction in cell viability. At lower dilutions (1:10, 1:50 and 1:100) all specimens showed no significant toxicity to hDPSCs, but an increase in cell proliferation.Significance: The experimental fluoride-doped calcium-phosphates are biocompatible and possess a clear ability to evoke fluoride-containing apatite-like crystallisation. Hence, they may be promising remineralising materials for dental applications.

Automated summary

This study evaluated the cytotoxicity, chemical and structural properties of fluoride-doped calcium-phosphates as potential remineralising materials for dental applications. Experimental calcium phosphates were tested for their ability to crystallise into apatite-like and their fluoride release. The materials showed biocompatibility and the ability to promote cell proliferation, indicating their potential use as remineralising materials in dentistry.