Development of a bioactive dentin adhesive resin modified with magnesium-doped synthetic hydroxyapatite crystals

The aim is to evaluate the development of an experimental multi-mode/Universal resin-based dentin adhesive modified with synthetic Mg2+ doped hydroxyapatite crystals (HAp) having self-remineralization and antibiofilm properties. HAp doped with Mg2+ was prepared by the precipitation method. Experimental adhesives were subjected to degree of conversion and X-ray diffraction test for size and crystal structure. Bond strength was tested, and electron microscopy (SEM/TEM) imaging of resin-dentin interface was done along with nanoleakage, nanoindentation, confocal and Raman analyses. S. mutans was analysed using CLSM images against modified adhesive specimens. Nucleating abilities within the resin-dentin specimens are determined by measuring Ca2+. Alkaline phosphatase, Runx2, and Ocn transcripts are amplified using quantitative polymerase chain reaction (q-PCR). A calcium assay is performed to quantify level of mineralisation. When compared to control adhesives, the 0.5% Hap/Mg2+ containing experimental dentin adhesive demonstrated improved interaction with dentin. The preservation of uniform intact hybrid layer with the absence of nanoleakage indicated dentin bond integrity with 0.5% HAP/Mg2+ modified adhesive. Self-remineralization and antibiofilm potentials are supported.

Automated summary

The aim of this study is to evaluate the development of an experimental multi-mode/Universal resin-based dentin adhesive modified with synthetic Mg2+ doped hydroxyapatite crystals (HAp) that have self-remineralization and antibiofilm properties. The experimental adhesive was tested for degree of conversion, X-ray diffraction, bond strength, electron microscopy imaging, nanoleakage, nanoindentation, confocal analysis, and Raman analysis. The effects of the modified adhesive on S. mutans, nucleating abilities, alkaline phosphatase, Runx2, Ocn transcripts, and level of mineralization were investigated. The experimental dentin adhesive with 0.5% Hap/Mg2+ demonstrated improved interaction with dentin and showed preservation of a uniform intact hybrid layer with the absence of nanoleakage, indicating dentin bond integrity.