Effect of surface preparation and light curing on penetration of silver particles from 38% silver diamine fluoride in dentin of primary teeth: An in vitro evaluation.

PURPOSE

To evaluate the effect of light cure, as well as various dentin surface treatment approaches, on the penetration depth of silver precipitating from 38% silver diamine fluoride into primary dentin tubules.

METHODS

The occlusal dentin surfaces of 42 non-carious primary molars were exposed and then sectioned into halves bucco-lingually. The halves from each tooth pair were randomly split in two mega-groups, and each mega-group was divided randomly as follows into six experimental groups: prepared by either carbide bur (G1, G2), ceramic bur (G3, G4), or erbium laser (G5, G6). SDF was then applied to all prepared surfaces, and finally even-numbered groups (G2, G4, G6) were light cured. One mega-group was assigned to quantitative evaluation of silver penetration depth along the axial wall, and the other mega-group was reserved for qualitative observation of relative silver distribution on the occlusal surface, both via scanning electron microscope.

RESULTS

No significant difference was observed in silver penetration depth between light cure and non-light cure groups (P= 0.8908). There was a statistically significant association between tooth preparation method and depth of silver penetration (P< 0.000001); laser-treated groups had significantly deeper silver penetration (1,148.9 µm G5, 1160.4 µm G6) than carbide bur (P< 0.05; 184.7 µm G1, 301.8 µm G2) or ceramic bur (P< 0.05; 184.1 µm G3, 131.0 µm G4) groups. A significant difference (P< 0.05) was noted in percentage occlusal surface coverage of particles between laser (51.4% G5, 35.8% G6) and carbide groups (21.1% G1, 19.3% G2). Light cure had no significant effect on the depth of silver penetration from 38% SDF in the dentin of primary teeth. Laser preparation resulted in deeper silver penetration than carbide or ceramic bur.

CLINICAL SIGNIFICANCE

Exposure of 38% silver diamine fluoride-treated dentin to light cure did not affect the depth of penetration of silver particles into the dentin tubules of primary teeth. Rather, tooth preparation approaches that reduce the smear layer, like laser ablation, resulted in the deepest penetration of silver into the tubules. Clinical application of these findings will depend on scenario and treatment aim.