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