Impact of demineralization, brushing, and remineralization sequences on dentin mineral retention and surface properties

This study investigates the effects of different treatment sequences involving demineralization, brushing, and remineralization on the calcium and phosphorus (Ca/P) content, surface roughness, and microhardness of dentin specimens. Bovine dentin samples were subjected to the following five treatment conditions: control, demineralization, demineralization followed by remineralization, demineralization followed by brushing then remineralization, and demineralization followed by remineralization then brushing. X-ray fluorescence spectroscopy was then utilized to assess the elementary composition changes, while scanning electron microscopy provided microstructural analyses. Surface roughness and microhardness were also quantified to assess the physical changes in dentin. The control group retained significantly higher Ca/P content compared with all treated groups, indicating that demineralization, regardless of subsequent treatment, leads to a substantial loss of hydroxyapatite. Among the treated groups, those that underwent remineralization immediately after demineralization manifested higher Ca/P retention compared with those that included brushing before remineralization. Additionally, microhardness measurements indicated that post-demineralization brushing negatively affected dentin's microhardness. The sequence of demineralization, brushing, and remineralization treatments significantly affects Ca/P retention in dentin, along with its surface roughness and microhardness. Pre-remineralization brushing diminished mineral recovery, whereas exposure to mineral-rich beverage immediately after demineralization resulted in greater mineral deposition.