IADR Abstract Archives
Mechanical Properties of Synthetic Dental Enamel
Objectives: To investigate biomimetic synthesis of enamel-like crystal layer that has similar morphology, chemical composition, and mechanical properties to native enamel under physiological conditions.
Methods: Freshly extracted human teeth were obtained and crowns were sectioned into slices with variable 0.5 to 6 mm depending on the intended test. Specimens were etched with 5% nitric acid to simulate erosion lesion on enamel surface. Specimens were then rinsed thoroughly with deionized water and immersed in a previously prepared calcification solution (BMS) with neutral pH. Additional designated Strontium, Fluoride ion concentrations and experimental ionic solution EnamelStrongTM were added, and specimens were then incubated at 37o C for different time intervals. Artificial saliva (AS) immersion was used as control. Morphology and elemental analysis were done using Scanning Electron Microscope and Energy Dispersive X-Ray Spectroscopy. Vicker’s Hardness was tested using Micromet 2003. Bruker Hysitron TS 77 Select nanoindenter was used for nanoscale mechanical testing.
Results: Plate-like crystal layer was formed in BMS and Strontium groups, while needle-like crystals were formed with fluoride containing groups. The Ca/P atomic ratio ranged between 1.3 to 1.6 suggesting the presence of different calcium phosphate phases. VHN results were significantly higher in EnamelStrong group than F group, with average of 3.13 GPa and 2.48 GPa respectively. Nano-indentation hardness values were also significantly higher in EnamelStrong and F groups with averages of 3.20 and 2.86 GPa, compared to AS, BMS, and Sr groups with averages of 0.06, 0.29, and 0.05 GPa respectively.
Conclusions: Synthetic enamel-like nanocrystals can be generated using biomimetic systems at physiological pH and temperature. Current study reveals the evidence of formation of a protective crystalline layer on enamel with matching or higher hardness than native enamel.
Methods: Freshly extracted human teeth were obtained and crowns were sectioned into slices with variable 0.5 to 6 mm depending on the intended test. Specimens were etched with 5% nitric acid to simulate erosion lesion on enamel surface. Specimens were then rinsed thoroughly with deionized water and immersed in a previously prepared calcification solution (BMS) with neutral pH. Additional designated Strontium, Fluoride ion concentrations and experimental ionic solution EnamelStrongTM were added, and specimens were then incubated at 37o C for different time intervals. Artificial saliva (AS) immersion was used as control. Morphology and elemental analysis were done using Scanning Electron Microscope and Energy Dispersive X-Ray Spectroscopy. Vicker’s Hardness was tested using Micromet 2003. Bruker Hysitron TS 77 Select nanoindenter was used for nanoscale mechanical testing.
Results: Plate-like crystal layer was formed in BMS and Strontium groups, while needle-like crystals were formed with fluoride containing groups. The Ca/P atomic ratio ranged between 1.3 to 1.6 suggesting the presence of different calcium phosphate phases. VHN results were significantly higher in EnamelStrong group than F group, with average of 3.13 GPa and 2.48 GPa respectively. Nano-indentation hardness values were also significantly higher in EnamelStrong and F groups with averages of 3.20 and 2.86 GPa, compared to AS, BMS, and Sr groups with averages of 0.06, 0.29, and 0.05 GPa respectively.
Conclusions: Synthetic enamel-like nanocrystals can be generated using biomimetic systems at physiological pH and temperature. Current study reveals the evidence of formation of a protective crystalline layer on enamel with matching or higher hardness than native enamel.
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