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Mechanically induced EPR signals in tooth enamel
D Aragno1, P Fattibene, S Onori
1Istituto Superiore di Sanità, Physics Laboratory, Rome, Italy.
Summary
Mechanical preparation of tooth enamel without water cooling creates a paramagnetic signal similar to high-temperature heating. This finding is crucial for accurate electron paramagnetic resonance (EPR) dosimetry.
Area of Science:
- Materials Science
- Analytical Chemistry
- Dosimetry
Background:
- Sample preparation for electron paramagnetic resonance (EPR) dosimetry of tooth enamel typically involves mechanical methods.
- Understanding potential artifacts introduced during sample preparation is critical for accurate EPR dosimetry.
Purpose of the Study:
- To investigate the paramagnetic signal generated by mechanical preparation of tooth enamel.
- To compare the mechanically induced signal with signals from thermal treatments.
- To elucidate the origin of the mechanically induced EPR signal.
Main Methods:
- Mechanical preparation of tooth enamel samples without water cooling.
- Electron paramagnetic resonance (EPR) spectroscopy.
- EPR spectrum simulation.
- Thermal treatment of enamel samples at temperatures above 600°C.
Main Results:
- Mechanical operations without water cooling generate a stable isotropic EPR signal (g ≈ 2.00320, linewidth ≈ 0.1 mT).
- This mechanically induced signal closely resembles the signal produced by heating enamel above 600°C.
- EPR spectrum simulation confirmed the similarity between mechanically and thermally induced signals.
Conclusions:
- The mechanically induced EPR signal in tooth enamel is attributed to a sample temperature increase during friction.
- This artifact must be considered during sample preparation for EPR dosimetry to ensure accurate results.
- Implementing water cooling during mechanical preparation is recommended to avoid signal generation.