4D microstructural changes in dentinal tubules during acid demineralisation

Nathanael Leung; Robert A Harper; Bin Zhu; Richard M Shelton; Gabriel Landini; Tan Sui

doi:10.1016/j.dental.2021.09.002

4D microstructural changes in dentinal tubules during acid demineralisation

Dent Mater. 2021 Nov;37(11):1714-1723. doi: 10.1016/j.dental.2021.09.002. Epub 2021 Sep 20.

Authors

Nathanael Leung¹, Robert A Harper², Bin Zhu¹, Richard M Shelton², Gabriel Landini², Tan Sui³

Affiliations

¹ Bioinspired Materials Group, Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK.
² School of Dentistry, College of Medical and Dental Sciences, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK.
³ Bioinspired Materials Group, Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK. Electronic address: t.sui@surrey.ac.uk.

PMID: 34548177
DOI: 10.1016/j.dental.2021.09.002

Abstract

Objective: Dental erosion is a common oral condition caused by chronic exposure to acids from intrinsic/extrinsic sources. Repeated acid exposure can lead to the irreversible loss of dental hard tissues (enamel, dentine, cementum). Dentine can become exposed to acid following severe enamel erosion, crown fracture, or gingival recession. Causing hypersensitivity, poor aesthetics, and potential pulp involvement. Improving treatments that can restore the structural integrity and aesthetics are therefore highly desirable. Such developments require a good understanding of how acid demineralisation progresses where relatively little is known in terms of intertubular dentine (ITD) and peritubular dentine (PTD) microstructure. To obtain further insight, this study proposes a new in vitro method for performing demineralisation studies of dentine.

Methods: Advanced high-speed synchrotron X-ray microtomography (SXM), with high spatial (0.325 μm) and temporal (15 min) resolution, was used to conduct the first in vitro, time-resolved 3D (4D) study of the microstructural changes in the ITD and PTD phases of human dentine samples (∼0.8 × 0.8 × 5 mm) during 6 h of continuous acid exposure.

Results: Different demineralisation rates of ITD (1.79 μm/min) and PTD (1.94 μm/min) and their progressive width-depth profiles were quantified, which provide insight for understanding the mechanisms of dentine demineralisation.

Significance: Insights obtained from morphological characterisations and the demineralisation process of ITD and PTD during acid demineralisation would help understand the demineralisation process and potentially aid in developing new therapeutic dentine treatments. This method enables continuous examination of relatively large volumes of dentine during demineralisation and also demonstrates the potential for studying the remineralisation process of proposed therapeutic dentine treatments.

Keywords: Acid demineralisation; Erosion; Intertubular dentine (ITD); Peritubular dentine (PTD); Synchrotron X-ray microtomography (SXM); Time-resolved 3D analysis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Dental Enamel
Dentin
Humans
Synchrotrons
Tooth Demineralization* / chemically induced
Tooth*