Revitalising Silver Nitrate for Caries Management

Abstract

Silver nitrate has been adopted for medical use as a disinfectant for eye disease and burned wounds. In dentistry, it is an active ingredient of Howe's solution used to prevent and arrest dental caries. While medical use of silver nitrate as a disinfectant became subsidiary with the discovery of antibiotics, its use in caries treatment also diminished with the use of fluoride in caries prevention. Since then, fluoride agents, particularly sodium fluoride, have gained popularity in caries prevention. However, caries is an infection caused by cariogenic bacteria, which demineralise enamel and dentine. Caries can progress and cause pulpal infection, but its progression can be halted through remineralisation. Sodium fluoride promotes remineralisation and silver nitrate has a profound antimicrobial effect. Hence, silver nitrate solution has been reintroduced for use with sodium fluoride varnish to arrest caries as a medical model strategy of caries management. Although the treatment permanently stains caries lesions black, this treatment protocol is simple, painless, non-invasive, and low-cost. It is well accepted by many clinicians and patients and therefore appears to be a promising strategy for caries control, particularly for young children, the elderly, and patients with severe caries risk or special needs.

Keywords: caries; early childhood caries; silver diamine fluoride; silver nitrate; sodium fluoride.

Figure 1

Scanning electron microscopy images of artificial dentine caries with and without topical application of 25% silver nitrate solution followed by 5% sodium fluoride varnish: (a) 8000× and (b) 20,000× magnification views of the group treated with silver nitrate and sodium fluoride; (c) 8000× and (d) 20,000× magnification views of the group treated with deionised water.

Figure 2

Dental caries before and after the application of 25% silver nitrate solution followed by 5% sodium fluoride varnish.