Ultrasonic measurement of dentin remineralization effects of dentifrices and silver diamine fluoride

Objective: This study investigated the dentin remineralization effect of the application of a functionalized tri-calcium phosphate (fTCP) dentifrice and a silver diamine fluoride (SDF) solution. Material and methods: The materials used were: a fluoride-containing dentifrice with fTCP (fTCP＋), a fluoride-containing dentifrice without fTCP (fTCP−) and a 38% SDF solution. Following treatment, the dentin slabs were immersed in a 0.1-M lactic acid buffer solution and then placed in artificial saliva. This procedure was repeated three times daily for 28 days. The propagation time of longitudinal ultrasonic velocities (UV) and the Knoop hardness (KH) of the samples were measured. The samples were also observed using scanning electron microscopy. Results: The SDF and fTCP＋ groups showed higher UV than the fTCP − group regardless of the application method. The F-SDF group at 28 days showed significantly higher UV (4121 ± 102 m/s) than the F-fTCP + group (3731 ± 65 m/s) (p <.05). The F-SDF group at 28 days showed significantly higher KH (47.4 ± 2.2) than the F-fTCP＋ group (43.3 ± 1.0) and the F-fTCP − group (42.9 ± 2.1) (p <.05). Closure of the dentinal tubules and crystal precipitation was detected on the surface of the fTCP＋ group to a greater extent than the fTCP − group. Conclusions: The fTCP-containing dentifrice and SDF solution effectively enhanced bovine dentin remineralization.