PT  - JOURNAL ARTICLE
AU  - Jong Seto
AU  - Jeremy A. Horst
AU  - Dilworth Y. Parkinson
AU  - John C. Frachella
AU  - Joseph L. DeRisi
TI  - Silver microwires from treating tooth decay with silver diamine fluoride
AID  - 10.1101/152199
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 152199
4099  - http://biorxiv.org/content/early/2017/12/20/152199.short
4100  - http://biorxiv.org/content/early/2017/12/20/152199.full
AB  - Silver diamine fluoride (SDF) is a brush-on treatment for tooth decay that stops 81% of cavitated caries lesions (dental cavities). Before this innovation, caries was treatable only with operative approaches (dental fillings). SDF-treated lesions harden and become resistant to further decay. We hypothesized that the hardening is due to reaction with silver, rather than classic fluoride-mediated remineralization, because infected dentin is not amenable to remineralization. Using synchrotron microCT with 1.3 μm resolution, we observe filamentous densities up to 500 μm in length and 0.25-7.0 μm in diameter, formed in situ by applying SDF to caries lesions. We show that these “microwires” fill voids in the lesion caused by disease, and permeate through surrounding dentinal tubules. Using spectroscopy, we confirm that the chemical composition of the observed microwires is predominantly silver. To our knowledge, this represents the first structural microscale observations resulting from clinical SDF treatment. These novel observations hint at mechanistic explanations for the first clinical method to harden carious dentin besides remineralization. We hypothesize that SDF may not only achieve its antimicrobial functions by biochemical interactions, but also through its inherent ability to integrate into dentin.