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.

Effect of Silver Diamine Fluoride (SDF) Application on Microtensile Bonding Strength of Dentin in Primary Teeth.

PURPOSE: The purpose of this study was to investigate the effect of silver diamine fluoride (SDF) on the microtensile bonding strength of resin composite to the dentin of primary molars. METHODS: Twelve primary molars were randomly assigned to either the control or the SDF groups, and microtensile bonding strength (mTBS) was measured. The surface morphology was evaluated by visual inspection and scanning electron microscopy (SEM) imaging. RESULTS: The mean±(SD) value of mTBS in the control and SDF group was 162.09±81.08 and 139.85±88.53, respectively (P=0.402). SEM images showed that, in the control group, the majority of the fractures occurred at the adhesive-dentin conjunction, while in the SDF group failure mostly occurred within the adhesives. CONCLUSIONS: Pretreating dentin with 38 percent silver diamine fluoride does not affect the bonding strength of composite resin to dentin. The fracture patterns observed suggest that bonding strength might be stronger between the adhesive and the SDF-applied dentin. Our data suggest that SDF can be used as a dentin pretreatment prior to resin restoration potentially contributing to secondary caries prevention in primary teeth.