Oriented and Ordered Biomimetic Remineralization of the Surface of Demineralized Dental Enamel Using HAP@ACP Nanoparticles Guided by Glycine

Abstract

Achieving oriented and ordered remineralization on the surface of demineralized dental enamel, thereby restoring the satisfactory mechanical properties approaching those of sound enamel, is still a challenge for dentists. To mimic the natural biomineralization approach for enamel remineralization, the biological process of enamel development proteins, such as amelogenin, was simulated in this study. In this work, carboxymethyl chitosan (CMC) conjugated with alendronate (ALN) was applied to stabilize amorphous calcium phosphate (ACP) to form CMC/ACP nanoparticles. Sodium hypochlorite (NaClO) functioned as the protease which decompose amelogenin in vivo to degrade the CMC-ALN matrix and generate HAP@ACP core-shell nanoparticles. Finally, when guided by 10 mM glycine (Gly), HAP@ACP nanoparticles can arrange orderly and subsequently transform from an amorphous phase to well-ordered rod-like apatite crystals to achieve oriented and ordered biomimetic remineralization on acid-etched enamel surfaces. This biomimetic remineralization process is achieved through the oriented attachment (OA) of nanoparticles based on non-classical crystallization theory. These results indicate that finding and developing analogues of natural proteins such as amelogenin involved in the biomineralization by natural macromolecular polymers and imitating the process of biomineralization would be an effective strategy for enamel remineralization. Furthermore, this method represents a promising method for the management of early caries in minimal invasive dentistry (MID).

Remineralization potential of nano-hydroxyapatite on enamel and cementum surrounding margin of computer-aided design and computer-aided manufacturing ceramic restoration

“…29 The proteins probably acted as a scaffold for ion exchange of NHA and CP. 22,31 These results relate to the capabilities of NHA gel and CP to perform the remineralization process. 13 The NHA has a significantly higher capability of remineralization than CP, and this is possibly related to the NHA's nanoparticle nature, which is compatible with tooth structure.…”

“…29 The protein matrix comprises ~1% of the organic part of a mature enamel, which possibly remains after demineralization and functions as the main scaffold for ionic conduction 30 and deposition in the nanogaps of the interprismatic space, as described by other studies. 30,31 The enamel proteins situated in the interprismatic space were possibly capable of capturing the mineral solutions and allowed for penetration of minerals along the sides of these crystallites. 29,31 This is also related with isomorphic and isoionic exchange processes in enamel crystals that occurred upon the diffusion of calcium and phosphate through the interprismatic spaces and converted into hydroxyapatite crystals.…”

“…30,31 The enamel proteins situated in the interprismatic space were possibly capable of capturing the mineral solutions and allowed for penetration of minerals along the sides of these crystallites. 29,31 This is also related with isomorphic and isoionic exchange processes in enamel crystals that occurred upon the diffusion of calcium and phosphate through the interprismatic spaces and converted into hydroxyapatite crystals. 29 The proteins probably acted as a scaffold for ion exchange of NHA and CP.…”

“…27,28 It was reported that NHA of 10-20 nm diameter and 60-80 nm length can promote the penetration of crystals into the interprismatic space through ion transportation and presumably united to the interprismatic protein, resulting in remineralization on the superficial layer of the artificial carious lesions and possibly reversing the progression of initial caries lesions. [29][30][31][32][33] However, there are no reported cases till date regarding the use of any NHA in gel preparation on the early therapeutic aspect in restorative dentistry. This study aims to assess the NHA effect in a gel form, a newly developed product containing 10% nanohydroxymethyl cellulose for surface remineralization of enamel and cementum around the margin of CAD-CAM ceramic restoration.…”

Applications of nano-materials in diverse dentistry regimes

“…The above technique could be a potential procedure for managing the initial caries in minimal invasive dentistry. 107 Liu et al demonstrated the ability of ferumoxytol to disrupt the intractable oral bio-lms and prevention of tooth decay (dental caries) through intrinsic peroxidase-like activities. Ferumoxytol binds to the bio-lm ultra-structure and produces free radicals from hydrogen peroxide (H 2 O 2 ), which causes in situ bacterial mortality through cell membrane disruptions and degradation of the extra-cellular polymeric substance matrix.…”