UCSF Protocol for Caries Arrest Using Silver Diamine Fluoride: Rationale, Indications and Consent aqueous silver has been long known to form this protective layer. 6 Decreased sensitivity in treated patients 7, 8 is consistent with the hydrodynamic theory of dentin hypersensitivity. 9
Dental caries is a complex progression involving dietary sugars, bacterial metabolism, demineralization and organic degradation. The collagenous organic matrix is exposed once a dentin surface is demineralized and destroyed by native and bacterial proteases to enable a lesion to enlarge. 10 Upon application of silver diamine fluoride to a decayed surface, the squamous layer of silver protein conjugates forms, increasing resistance to acid dissolution and enzymatic digestion. 11 Hydroxyapatite and fluorapatite form on the exposed organic matrix, along with the presence of silver chloride and metallic silver. 5 The treated lesion increases in mineral density and hardness while the lesion depth decreases. 5 Meanwhile, silver diamine fluoride specifically inhibits the proteins that break down the exposed dentin organic matrix: matrix metalloproteinases, 11 cathepsins 12 and bacterial collagenases. 5 Silver ions act directly against bacteria in lesions by breaking membranes, denaturing proteins and inhibiting DNA replication. 13, 14 Ionic silver deactivates nearly any macromolecule. Silver diamine fluoride outperforms other anticaries medicaments in killing cariogenic bacteria in dentinal tubules. 15
Silver and fluoride ions penetrate ~ 25 microns into enamel 16 and 50-200 microns into dentin. 17 Fluoride promotes remineralization, and silver is available for antimicrobial action upon release by re-acidification. 18
Silver diamine fluoride arrested lesions are 150 microns thick. 19
Artificial lesions treated with silver diamine fluoride are resistant to biofilm formation and further cavity formation,
20, 21
presumably due to remnant ionic silver. More silver and fluoride is deposited in demineralized than nondemineralized dentin. Correspondingly, treated demineralized dentin is more resistant to caries bacteria than treated sound dentin. 22 When bacteria killed by silver ions are added to living bacteria, the silver is re-activated so that effectively the dead bacteria kill the living bacteria in a“ zombie effect.” 23 This reservoir effect helps explain why silver deposited on bacteria and dentin proteins within a cavity has sustained antimicrobial effects.
|
Arrested caries
100 %
50 %
0 %
|
308 3-5 year olds | 6 lesions at start Chu et al., 2002
0.5 1 1.5 2 2.5 3
|
SDF q1year exc SDF q1year exc NaF q3mon NaF q3mon control |
Arrested caries
100 %
50 %
0 %
|
624 3-9 year olds | 6.8 lesions at start Yee et al., 2009
0.5 1 1.5 2 2.5 3
|
SDF once SDF, tannate 12 % SDF once control |
|
Time( years) |
|
|
Time( years) |
|
100 % |
227 60-89 year olds | 0.91 lesions at start Zhang et al., 2013 |
|
100 % |
322 5-6 year olds | 3.8 lesions at start Santos et al., 2014 |
|
Arrested caries |
50 % |
SDF q1year + OHI q6mon control |
Arrested caries |
50 % |
30 % SDF once GIC once |
0 % |
0.5 1 1.5 2 2.5 3 |
0 % |
0.5 1 1.5 2 2.5 3 |
|
Time( years) |
|
Time( years) |
JANUARY / FEBRUARY 2017 | PENNSYLVANIA DENTAL JOURNAL 17