Promotion Effect of Carboxymethyl Chitosan on Dental Caries via Intrafibrillar Mineralization of Collagen and Dentin Remineralization

Abstract

Objective: To observe ultrastructural changes during the process of carboxymethyl chitosan (CMC)-mediated intrafibrillar mineralization, we evaluated the biomimetic remineralization potential of CMC in type-I collagen fibrils and membranes, and further explored the bond strength as well as the bond interfacial integrity of the biomimetic remineralized artificial caries-affected dentin (ACAD). Methods: A mineralized solution containing 200 μg/mL CMC was used to induce type-I collagen biomimetic remineralization in ACAD, while traditional mineralization without CMC was used as a control. The process and pattern of mineralization were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) as well as structured illumination microscopy (SIM). The Vickers hardness test was used to quantify the dentin hardness, while the microtensile bond strength (µTBS) test was used to assess the bond strength and durability. The bond interfacial integrity was evaluated by a confocal laser scanning microscope (CLSM). Results: TEM, SEM, and SIM images showed that CMC had a positive effect on stabilizing amorphous calcium phosphate (ACP) and promoting intrafibrillar mineralization, while extrafibrillar mineralization was formed without CMC. Furthermore, hardness evaluation and µTBS proved that CMC significantly increased dentin hardness and bond strength. CLSM indicated that CMC could create a significantly better bond interfacial integrity with less of a micro-gap in ACAD. Significance: CMC possessed the ability to promote intrafibrillar mineralization and remineralization in demineralized caries dentin lesions, as well as improve bond performance, which implied its potential in carious dentin demineralization or dentin hypersensitivity and possibly even as a possible material for indirect pulp-capping, to deal with deep caries. Highlights: CMC possessed the ability to induce intrafibrillar mineralization effectively; the bond strength and bond durability of demineralized caries dentin were improved via CMC-induced remineralization; the CMC-induced remineralization complex is a potential material for indirect pulp-capping, to deal with deep caries.

Remineralization of Dentinal Lesions Using Biomimetic Agents: A Systematic Review and Meta-Analysis

“…The precursors seep into gap zones of collagen fibrils and result in intrafibrillar remineralization. This also causes the interfibrillar remineralization of collagen fibrils [ 108 ].…”

Synergistic intrafibrillar/extrafibrillar mineralization of collagen fibrils and scaffolds enhanced by introducing polyacrylamide to PILP for osteogenic differentiation

“…Previous studies have stabilized amorphous precursors using various polymer analogs of dentin matrix protein‐1 (DMP‐1), such as polyaspartic acid, PAA, and poly(levoglutamic acid) 31,38–40 . DMP‐1 stabilizes amorphous calcium phosphate (ACP) and forms the DMP‐1/ACP nanocomplex, which plays a crucial role in the internal mineralization of collagen fibers 41–44 . This process comprises a minor phase of metastable, amorphous, liquid‐phase nanodroplets, which are ACP precursors 31 .…”

“…31,[38][39][40] DMP-1 stabilizes amorphous calcium phosphate (ACP) and forms the DMP-1/ACP nanocomplex, which plays a crucial role in the internal mineralization of collagen fibers. [41][42][43][44] This process comprises a minor phase of metastable, amorphous, liquid-phase nanodroplets, which are ACP precursors. 31 Some researchers have proposed that precursors are drawn into the nanogaps of collagen fibers through capillary forces, where they undergo water loss, solidification, and crystallization.…”

An engineered dual-functional peptide with high affinity to demineralized dentin enhanced remineralization efficacy in vitro and in vivo

“…5,6 However, collagen fibers, as the main components of demineralized dentin, have a weak ability to initialize hydroxyapatite (HA) nucleation and growth. 7 Hence, developing remineralization agents to promote and regulate apatite crystallization is of high clinical significance to treat dental caries.…”