RADIANT – Raman based probe and decision-making tool for dental diagnostics in preventive dentistry

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Raman based probe and decision-making tool for dental diagnostics in preventive dentistry, aiming to reduce the need for painful and expensive treatments.


Half of the world population has suffered or will suffer from oral disease. This tool aims at tackling this problem and reducing the need for painful and expensive treatments. A paradigmatic shift has been occurring in Dentistry where a more preventive and conservative approach is pursued, with election of demineralization management instead of invasive and reconstructive treatments. In this framework, there is need for a sensitive and accurate tool for the earliest diagnosis possible, before it is even detected by an expert’s visual evaluation. Raman spectroscopy can be that tool.


The Raman spectroscopy technique measures the characteristic scattered radiation by molecules after monochromatic laser irradiation. When dealing with human enamel, mainly composed of carbonated hydroxyapatite, there are several molecular vibrational modes that are Raman active, the most intense being the symmetric stretching band of phosphate in the hydroxyapatite (Ca10(PO4)6(OH)2) matrix. In recent decades, polarized Raman spectroscopy has been shown to effectively differentiate between sound and carious enamel in ex vivo measurements performed in controlled in vitro conditions. The major impairment for using this spectroscopic technique, in vivo, is the hindering of the Raman signal due to fluorescence background (by organic compounds) or ambient light. RADIANT probe solves the problem of fluorescence by implementing time-gated technology in the Raman setup, greatly increasing the sensitivity of the Raman detection. In order to surpass even the most skilled dentist in assessing demineralization, the RADIANT tool implements Machine Learning algorithms. These, coupled to a database of Raman spectra of teeth that were demineralized to several degrees, will enable high accuracy and precision in the identification of incipient carious lesions.


S. Pessanha, S. Silva, J. M. Silveira, I. Otel, H. Luis, V. Manteigas, A. P. Jesus, A. Mata, M. Fonseca, Evaluation of the effect of fluorinated tooth bleaching products using polarized Raman microscopy and particle induced gamma-ray emission, Spectrochimica Acta Part A, 236 (2020) 118378

M. Cândido, J. M. Silveira, A. Mata, M. L. Carvalho, S. Pessanha, In vitro study of the demineralization induced in human enamel by an acidic beverage using Raman and X Ray Fluorescence spectroscopies, X Ray spectrometry, 48 (2019) 61–69

G. Luís, H. Silva, J. M. Silveira, V. Manteigas, A. Mata, A. P. Jesus, M. Fonseca, S. Pessanha, Evaluation of enamel demineralization and fluorine uptake caused by gustatory stimulants of salivary secretion (GSSS) using PIGE and Raman spectroscopy, Journal of Raman Spectroscopy, 50 (2019) 380-386.

M. Monteiro, F. Chasqueira, S. Pessanha, Raman spectroscopy in the characterisation of carious dental tissues, Spectrosc. Eur. 30 (2018) 9-12

J. Silveira, S. Coutinho, D. Marques, J. Castro, A. Mata, M.L. Carvalho, S. Pessanha, Raman spectroscopy analysis of dental enamel treated with whitening product – Influence of saliva in the remineralization, Spectrochimica Acta A, 198 (2018) 145-149


TRL 3 – experimental proof of concept.


Conventional clinical diagnostic methods, such as visual detection or probing with dental explorer, are characterized by their qualitative nature not to mention the subjective expertise of the practitioner. These methods are commonly aided by digital radiography or, more recently, by other methods based on changes in optical properties of enamel, taking advantage of the porosity induced by demineralization. However, the sensitivity and specificity of these diagnostic tools is poor, particularly when compared to Raman spectroscopy. Moreover, they sometimes do not provide a quantitative evaluation, they still need the expertise of the doctor for evaluation, or they are strongly dependant of the ambient light calibration, and the same for contamination from organic material. Raman scattering is sample dependent, and our tool provides quantitative, objective, evaluation.
• High ionic conductivity – stable with temperature, stable at atmospheric conditions.
• Characteristics – light weight, flexible, paper based, possible large area production


  • Dental practices for regular evaluation and assessment;
  • Preventive dentistry industry: Testing and certifying safety of products.


Seeking co-development partners

Diagnosis; preventive dentistry; Machine Learning.


Know-how based.

NOVA Inventors

Sofia Pessanha

Sara Silva

Iulian Otel

Vasco Manteigas

Adelaide Pedro de Jesus

Micaela Fonseca

Gonçalo Luís

Hugo Silva

Mariana Monteiro

Filipa Chasqueira

Luisa de Sousa Leonardo

Academic Information | NOVA School of Science and Technology | FCT NOVA