Polished Tooth

A focus on
April is Oral Health Month
By Niki Fontaine, RDH

Silver Diamine Fluoride (SDF) Arrests Caries (decay) in Children & Prevents Root Surface Caries in Adults
. This month I wanted to write something more on prevention as April is Oral Health Month and this edition’s focus is on kids.

Silver Diamine Fluoride (SDF)—what is it?

A mixture of:

25% silver: antimicrobial
  • 8% ammonia: solvent
  • 5% fluoride: remineralization

Fluoride action:

Promotes remineralization
  • Inhibits demineralization
  • Can inhibit plaque bacteria

SDF—what does it do?

  • Arrests dental caries
  • Prevents dental caries directly & indirectly
  • Decreases dentin hypersensitivity

SDF—how does it work?

  • 38% SDF contains 44,800 ppm F & 253,870 ppm Ag
  • Sodium fluoride (NaF) & Silver nitrate (AgNO3)
  • Reacts with hydroxyapatite producing calcium fluoride (CaF2) and silver phosphate (Ag3PO4)


  • Crystal of low solubility in the oral environment
  • Yellowish colour—darkened by sunlight or reducing agents
  • SDF inhibits dentin demineralization, preserves collagen and inhibits collagen breakdown, increases dentin hardness
  • Forms silver‐protein conjugate on decayed dentin, increasing resistance to acid dissolution and enzymatic digestion
  • Hydroxyapatite and fluorapatite form on exposed organic matrix
  • Inhibits proteins that break down exposed dentin organic matrix


  • Reservoir of fluoride
  • Neutralizes imbalance in demineralization/mineralization

Where did this come from?

  • Silver Nitrate used globally for >1000 years.
  • AgF used in Japan for over 900 years, Cosmetic blackening of teeth, Known to prevent caries
  •  NH3 + added >80 years ago = SDF: Approved & monitored by Japan
  • Available in Australia, Brazil, Argentina, Cuba, China since 1980s or before…

When would you use SDF?

  • Extreme caries risk
  • Behaviour or medical management challenges
  • More lesions than treatable at 1 visit
  • Difficult to treat lesions (including root surface caries)
  • Patients without access to care
  • Young patients’ wait‐listed for OR‐based dental treatment

How safe is SDF?

  • No adverse reports in >80 years of use in Japan
  • Contraindication – Silver allergy
  • Relative contraindication: significant desquamative processes e.g. ulcerative gingivitis, stomatitis → Protect area by petroleum jelly
  • Side effects: Small, white mucosal lesions disappear in 48 hours – Will stain the lesion black

Why I think SDF can be a game‐changer in Dental Public Health

  • SDF arrests ~80% caries when used 2/year
  • Powerful indirect prevention
  • Inexpensive
  • Benefits far outweigh risks
  • Easily used in field settings
  • May be applied by dental hygienists
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