Assessment of demineralized tooth lesions using optical coherence tomography and other state-of-the-art technologies: a review

Table 4 Characteristics of the clinical and research tools for tooth assessment (Adapted from [18, 22, 35, 37, 44, 49, 51, 64–74])

	Involvement of ionizing radiation	Image dimension	In vivo/ex vivo	Spatial resolution	Penetration depth	Properties assessed
Transverse microradiography	Yes	2D	Ex vivo	0.3 μm–10 μm	50 μm–100 μm	Mineral density, depth
Scanning electron microscopy	No	2D	Ex vivo	0.05 μm -0.1 μm	1 μm–5 μm	Surface topography
Atomic force microscopy	No	3D	Ex vivo	Lateral: 0.001 μm Axial: 0.0001 μm	10 μm–20 μm	Surface topography
Confocal microscopy	No	3D	In vivo, ex vivo	Lateral: 0.18 μm–0.3 μm Axial: 0.5 μm–0.8 μm	300 μm	Surface roughness
Raman spectroscopy	Yes	2D	Ex vivo	0.2 μm–1.0 μm	0.002 μm–2 μm	Degree of crystallinity, mineral composition
Impedance spectroscopy	No	1D	Ex vivo	–	100 μm–200 μm	Porosity
Profilometry	No	2D	Ex vivo	5.0 μm	0.05 μm–1 μm	Surface topography
Microhardness, nanohardness test	No	1D	Ex vivo	–	500 μm–2000 μm	Microhardness, nanohardness value
Optical coherence tomography	No	3D	In vivo, ex vivo	Transverse: 25 μm^a Axial (water/air): 12 μm /9 μm^a	1000 μm–1500 μm	Enamel depth, optical attenuation, 3D morphology

ISSN: 1475-925X