Remineralizing effects of hydroxypropyl methylcellulose film-loaded amorphous calcium phosphate nanoprecursors on enamel artificial caries lesions

Zhixin Zhang; Zihan Cui; Jianping Zhang; Haiyan Zheng; Zihuai Zhou; Zhifang Wu; Zhe Wang; Baiping Fu

doi:10.1016/j.jmbbm.2024.106408

Remineralizing effects of hydroxypropyl methylcellulose film-loaded amorphous calcium phosphate nanoprecursors on enamel artificial caries lesions

J Mech Behav Biomed Mater. 2024 Mar:151:106408. doi: 10.1016/j.jmbbm.2024.106408. Epub 2024 Jan 17.

Authors

Zhixin Zhang¹, Zihan Cui², Jianping Zhang³, Haiyan Zheng², Zihuai Zhou², Zhifang Wu², Zhe Wang⁴, Baiping Fu⁵

Affiliations

¹ Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, 310000, China; Department of Stomatology, Quanzhou First Hospital Affiliated to Fujian Medical University, Quanzhou, 362000, Fujian, China. Electronic address: 1934800300@qq.com.
² Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, 310000, China.
³ Department of Orthopaedics, The 909th Hospital, School of Medicine, Xiamen University, Zhangzhou, 363000, Fujian, China.
⁴ Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, 310000, China. Electronic address: 7319012@zju.edu.cn.
⁵ Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, 310000, China. Electronic address: fbp@zju.edu.cn.

PMID: 38244421
DOI: 10.1016/j.jmbbm.2024.106408

Abstract

Objectives: This study was to investigate hydroxypropyl methylcellulose (HPMC) film as a carrier for amorphous fluorinated calcium phosphate (AFCP) nanoprecursors to continuously deliver biomimetic remineralization of enamel artificial caries lesions (ACL).

Materials and methods: The AFCP/HPMC films were comprised of 25 wt% AFCP nanoparticles and 75 wt% HPMC. They were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and biocompatibility tests. Forty enamel ACL were prepared and randomly divided into four groups (n = 10): The enamel surfaces were covered with a pure HPMC film, Tooth Mousse Plus (contains 10% CPP-ACP and 0.2% NaF), and AFCP/HPMC film, or without any things (serving as negative control). Subsequently, all samples were alternatively kept in artificial saliva and a modified pH-cycling before they were characterized by Micro-CT, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflectance (ATR)-FTIR, XRD, and nanoindentation.

Results: After the enamel ACL was challenged by pH cycling, Tooth Mousse Plus and AFCP/HPMC film groups exhibited less lesion depth and mineral loss than the negative control and pure HPMC film groups. Additionally, the AFCP/HPMC film group revealed a highest remineralization rate of 55.34 ± 3.10 % among the all groups (p < 0.001). The SEM findings showed that the enamel ACL were densely deposited with minerals in the AFCP/HPMC film group, and the EDX results suggested a higher content of fluorine in the remineralized tissues. In particular, the AFCP/HPMC film group exhibited the best nanomechanical performance after 2 weeks of pH cycling (p < 0.05), with the hardness (H) restored from 0.29 ± 0.19 to 2.69 ± 0.70 GPa, and elastic modulus (Er) restored from 10.77 ± 5.30 to 68.83 ± 12.72 GPa.

Conclusion: The AFCP/HPMC film might be used as a promising strategy for arresting or reversing incipient enamel caries lesions.

Keywords: Calcium phosphate nanoprecursors; Enamel caries; Nanoindentation; Remineralization.

MeSH terms

Calcium Phosphates
Dental Caries Susceptibility*
Dental Caries* / drug therapy
Humans
Hypromellose Derivatives
Minerals
Tooth Remineralization / methods

Substances

amorphous calcium phosphate
Hypromellose Derivatives
Calcium Phosphates
Minerals