Author Name/s: Abshar Hasan, Andrey Chuvilin, Alexander Van Teijlingen, Helena Rouco, Christopher Parmenter, Federico Venturi, Michael Fay, Gabriele Greco, Nicola M. Pugno, Jan Ruben, Charlotte J. C. Edwards-Gayle, Benjamin Myers, Ingrid Dreveny, Nathan Cowieson, Adam Winter, Sara Gamea, X. Frank Walboomers, Tanvir Hussain, José Carlos Rodríguez-Cabello, Frankie Rawson, Tell Tuttle, Sherif Elsharkawy, Avijit Banerjee, Stefan Habelitz & Alvaro Mata
Journal Reference: Hasan, A., Chuvilin, A., Van Teijlingen, A. et al. Biomimetic supramolecular protein matrix restores structure and properties of human dental enamel. Nat Commun 16, 9434 (2025). https://doi.org/10.1038/s41467-025-64982-y
Background:
Enamel’s composition and structure makes it the hardest and most mineralised tissue of vertebrates. During enamel development, the protein amelogenin transforms into aligned and densely packed carbonated hydroxyapatite nanocrystals, which forms its many physical properties. However, mature enamel loses the cells responsible for its generation, meaning that it cannot regenerate itself. Over time, exposure to forces increases the risk of permanent damage, like fracture, dentinal sensitivity and tooth loss.
Aims:
This study focuses on the performance of supramolecular protein matrices by using disordered elastin-like recombinant (ELR) molecules. It intended to recreate the anatomical structure of enamel that contributes to its mechanical properties and whether it could withstand the challenges within the mouth.
Methodology:
The study was ex-vivo, with the ELR matrix applied to acid-eroded enamel and exposed dentine on extracted teeth. Mechanical properties of natural, acid-eroded and remineralised enamel was tested:
- Stiffness, Hardness and Fracture Toughness: a small Berkovich diamond tip was pressed into the enamel surface to measure the relationship between the applied force and indentation depth, measuring the effect on elastic and permanent deformation. These results were combined with crack length to calculate fracture resistance.
- Friction Resistance and Wear Strength: a 6mm aluminium oxide ball was pressed into the enamel and moved on a circular track for 200 cycles. The shape and depth of surface loss was measured using optical profilometry.
- Withstand Toothbrushing Abrasion: an Oral-B electric toothbrush with 16g of Oral-B Pro-Expert toothpaste was used to brush the sample continuously for 15 minutes and then 60 minutes using circular movements.
- Withstand erosion: nanoindentation measured Young’s Modulus before and after enamel was exposed to acetic acid at 37 degrees (pH 4.0)
- Exist in biologically relevant environment: enamel samples coated in human saliva for 14 days and measure nanoindentation.
Results:
The ELR matrix successfully formed Ca2+-dependant fibrils in an orientation guided by existing tooth structure, with mineralised layers up to 10µm. With many of the tested characteristics, remineralisation of the acid-etched enamel increased the ability of the enamel, regaining mechanical properties similar to that of healthy enamel. For example, fracture toughness increased from 0.7 ± 0.1 MPa.m0.5 to 1.1 ± 0.1 MPa.m0.5 between acid-eroded and the remineralised enamel, with 1.2 ± 0.2 MPa.m0.5 being the fracture toughness of natural enamel.
Discussion:
The significance of this study, is that it suggests the ELR matrix attempts to reproduce the natural mechanism of enamel development with mineralisation exending into exposed dentine, as opposed to depositing calcium phosphate onto tooth surfaces. Functionally, it can perform similarly to natural enamel under mechanical and chemical challenges normally found in the mouth.
However, the study was completed ex-vivo, using extracted teeth and laboratory mineralising conditions. The challenges in the mouth are much more vast: from saliva, bacteria, fluctuating pH and temperature to continuous exposure to food and drink.
Conclusion:
This study shows ELR could be considered a potential future treatment for enamel erosion, tooth wear and dentine exposure by acting as an artificial enamel-forming scaffold. By guiding organised apatite growth it can restore several important mechanical and chemical functions of enamel. However, the study does not reflect real day-to-day challenges natural enamel has to overcome.
Research summary written by: Aaminah Patel
University of Manchester, BDS 3