Oral · Published 2026-08-05 · DOI 10.3390/oral6040100
Nourhan Elmoghazy, Mahmoud M. Bakr, Nada Tarek, Mahmoud Al Ankily, Mohamed Shamel
<b>Objectives:</b> This study aimed to evaluate and compare the effects of 38% silver diamine fluoride (SDF) and nano-hydroxyapatite (nHAp) toothpaste on dentinal tubule surface area, elemental composition, and microhardness of mechanically exposed dentin. <b>Methods:</b> Thirty extracted human molars with standardized exposed occlusal dentin were randomly assigned to control, SDF, or nHAp groups (<i>n</i> = 10 each). Surface morphology and dentinal tubule area were assessed using scanning electron microscopy, elemental composition by energy-dispersive X-ray spectroscopy, and microhardness by Vickers testing before and after application of SDF and nHAp. Data were analyzed using one-way ANOVA with Bonferroni post hoc tests and paired <i>t</i>-tests (α = 0.05). <b>Results:</b> Baseline dentinal tubule area and microhardness were comparable among groups. SDF showed the strongest effects, reducing dentinal tubule area by 84.5% and producing the greatest microhardness increase (<i>p</i> < 0.001), while nHAp reduced dentinal tubule area by 45.2% and increased microhardness within the group (<i>p</i> < 0.001). Calcium content was highest in the SDF group (<i>p</i> < 0.001), whereas phosphorus showed no significant difference (<i>p</i> = 0.195). The Ca/P ratio differed overall (<i>p</i> = 0.046), mainly between Control and SDF (<i>p</i> = 0.024). Scanning electron microscopy confirmed dense tubule occlusion with SDF, partial occlusion with nHAp, and open tubules in controls. <b>Conclusions:</b> SDF produced greater dentinal tubule occlusion and microhardness improvement than nHAp toothpaste in this short-term in vitro model using mechanically exposed dentin. nHAp toothpaste produced moderate tubule occlusion and a smaller improvement in microhardness under the tested conditions.
Abstract from DOAJ. Public domain (CC0 1.0).
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Elmoghazy, N., Bakr, M., Tarek, N., et al. (2026). Effects of Silver Diamine Fluoride and Nano-Hydroxyapatite Toothpaste on Surface Morphology, Elemental Composition, and Microhardness of Mechanically Exposed Dentin—An In Vitro Study. Oral. https://doi.org/10.3390/oral6040100