Demineralization and breakdown of tooth enamel are characterized by a condition called
dental caries or tooth decay, which is caused by two main factors: (1) highly acidic food intake without proper
oral hygiene and (2) overactive oral bacteria generating acidic metabolic byproducts.
Fluoride treatments have been shown to help rebuild the
hydroxyapatite structures that make up 98% of enamel but do not tackle the bacterial overload that continues to threaten future demineralization. Herein, we have created a dual-function
Pluronic F127-alginate
hydrogel with
nitric oxide (NO)- and
fluoride-releasing capabilities for the two-pronged treatment of
dental caries. Analysis of the
hydrogels demonstrated porous, shear-thinning behaviors with tunable mechanical properties. Varying the weight percent of the NO donor
S-nitrosoglutathione (GSNO) within the
hydrogel enabled physiologically actionable NO release over 4 h, with the fabricated
gels demonstrating storage stability over 21 days. This NO-releasing capability resulted in a 97.59% reduction of viable Streptococcus mutans in the planktonic state over 4 h and reduced the preformed biofilm mass by 48.8% after 24 h. Delivery of
fluoride ions was confirmed by a
fluoride-sensitive
electrode, with release levels resulting in the significant prevention of demineralization of
hydroxyapatite discs
after treatment with an acidic demineralization
solution. Exposure to human gingival fibroblasts and human osteoblasts showed cytocompatibility of the
hydrogel, demonstrating the potential for the successful treatment of
dental caries in patients.