Self-Etch Adhesive as a Carrier for ACP Nanoprecursors to Deliver Biomimetic Remineralization

Abstract

Lab biomineralization should be carried out in an actual clinical practice. This study evaluated self-etch adhesive as a carrier for amorphous calcium phosphate (ACP) nanoprecursors to continuously deliver biomimetic remineralization of self-assembly type I collagen and demineralized dentin. Si-containing ACP particles (Si-ACP) stabilized with polyaspartic acid (PAsp) were synthesized and characterized by transmission electron microscopy (TEM), scanning electron microscopy-energy-dispersive X-ray spectroscopy, Fourier transform infrared analysis, X-ray powder diffractometry, and X-ray phototelectron spectroscopy. The biomimetic remineralization of single-layer reconstituted type I collagen fibrils and demineralized dentin was analyzed by using two one-bottle self-etch dentin adhesives (Clearfil S3 Bond (S3), Kurraray-Noritake; Adper Easy One (AEO), 3 M ESPE) as a carrier loaded (or not, in the case of the control) with 25 wt % of Si-ACP particles. In vitro cytotoxicity assessed by the Cell Counting Kit-8 indicated that the Si-ACP particles had no adverse effect on cell viability. The capacity for Ca and P ions release from cured Si-ACP-containing adhesives (S3, AEO) was evaluated by inductively coupled plasma-atomic emission spectrometry, revealing the successively increasing release of Ca and P ions for 28 days. The intra- and extrafibrillar remineralization of type I collagen and demineralized dentin was confirmed by TEM and selected-area electron diffraction when the adhesives were used as a carrier loaded with Si-ACP particles. Therefore, we propose self-etch adhesive as a novel carrier for ACP nanoprecursors to continuously deliver biomimetic remineralization.