The preventive effect of silver diamine fluoride-modified salivary pellicle on dental erosion

To investigate the preventive effect of silver diamine fluoride (SDF) modified salivary pellicle (SP) against dental erosion.

Enamel and dentin blocks allocated into 4 groups (n = 30 each). Blocks in Group SDF+SP were treated with SDF and SP. Blocks in Group SDF were treated with SDF. Blocks in Group DW+SP were treated with deionized water (DW) and SP. Blocks in Group DW were treated with DW. The blocks were subjected to an erosive challenge at pH 3.2 for 2 mins, 5 times per day for 14 days. Salivary pellicle morphology was assessed by atomic force microscopy (AFM). Crystal characteristics, percentage microhardness loss (%SMHL), surface loss, and surface morphology were assessed by X-ray diffraction (XRD), microhardness test, profilometry, and scanning electron microscopy (SEM), respectively.

AFM revealed a modified pellicle morphology in Group SDF+SP. XRD of both blocks revealed hydroxyapatite, silver chloride, silver phosphate, and silver fluoride in Groups SDF+SP and SDF. Fluoroapatite was found in Group SDF+SP only. %SMHL ( ± Standard deviation in %) of Groups SDF+SP, SDF, DW+SP, and DW were 33.4 ± 2.2, 38.6 ± 2.2, 50.3 ± 2.2, and 58.3 ± 2.4 in enamel and 16.1 ± 2.2, 19.7 ± 2.1, 32.8 ± 2.1, and 39.0 ± 2.3 in dentin, respectively. The presence of SDF and SP reduced %SMHL in both blocks (p < 0.001). The surface loss ( ± Standard deviation in μm) of Groups SDF+SP, SDF, DW+SP, and DW were 3.6 ± 0.7, 4.1 ± 0.4, 5.3 ± 0.5, and 7.0 ± 0.6 in enamel and 5.4 ± 0.6, 6.1 ± 0.5, 9.1 ± 0.7, and 9.2 ± 0.5 in dentin, respectively. The presence of SDF and SP reduced surface loss in enamel and dentin blocks (p = 0.031 and p = 0.002, respectively). SEM showed enamel surface remained relatively smooth and partially dentinal tubule occlusion on dentin blocks in Groups SDF+SP and SDF.

SDF had a positively synergistic effect with SP. SDF-modified salivary pellicle provided a superior protective effect against dental erosion.