Raman Spectroscopy: A Potential Diagnostic Tool for Oral Diseases

Abstract

Oral diseases impose a major health burden worldwide and have a profound effect on general health. Dental caries, periodontal diseases, and oral cancers are the most common oral health conditions. Their occurrence and development are related to oral microbes, and effective measures for their prevention and the promotion of oral health are urgently needed. Raman spectroscopy detects molecular vibration information by collecting inelastic scattering light, allowing a “fingerprint” of a sample to be acquired. It provides the advantages of rapid, sensitive, accurate, and minimally invasive detection as well as minimal interference from water in the “fingerprint region.” Owing to these characteristics, Raman spectroscopy has been used in medical detection in various fields to assist diagnosis and evaluate prognosis, such as detecting and differentiating between bacteria or between neoplastic and normal brain tissues. Many oral diseases are related to oral microbial dysbiosis, and their lesions differ from normal tissues in essential components. The colonization of keystone pathogens, such as Porphyromonas gingivalis, resulting in microbial dysbiosis in subgingival plaque, is the main cause of periodontitis. Moreover, the components in gingival crevicular fluid, such as infiltrating inflammatory cells and tissue degradation products, are markedly different between individuals with and without periodontitis. Regarding dental caries, the compositions of decayed teeth are transformed, accompanied by an increase in acid-producing bacteria. In oral cancers, the compositions and structures of lesions and normal tissues are different. Thus, the changes in bacteria and the components of saliva and tissue can be used in examinations as special markers for these oral diseases, and Raman spectroscopy has been acknowledged as a promising measure for detecting these markers. This review summarizes and discusses key research and remaining problems in this area. Based on this, suggestions for further study are proposed.

Raman microspectroscopy/micro‐optical coherence tomography approach for chairside diagnosis of periodontal diseases: A pilot study

“…Other studies have attempted to characterize periodontal tissues through unilateral modalities. [22][23][24] Chifor et al concluded that periodontal ultrasonography can accurately visualize the dentino-enamel junction, cortical bone, and gingival tissues to diagnose periodontal status. 25 Similarly, Tattan et al reports that ultrasonic imaging can provide accurate periodontal diagnosis without concerns about ionizing radiation when compared with clinical and CBCT readings.…”

“…To the best of the authors’ knowledge, this is the first study to combine RMS and μOCT into a single optical device for measurement of periodontal activity status. Other studies have attempted to characterize periodontal tissues through unilateral modalities 22–24 . Chifor et al.…”

Development of a Visualisation Approach for Analysing Incipient and Clinically Unrecorded Enamel Fissure Caries Using Laser-Induced Contrast Imaging, MicroRaman Spectroscopy and Biomimetic Composites: A Pilot Study

“…At the same time, the screening techniques applied in clinics sometimes suffer a lack of selectivity with respect to the separation of the intact and infected tissues, as sensitivity and reliability are needed for convenient and routine instruments for the practical diagnostics of the dental status of teeth under external inspection [ 30 , 33 ]. In our opinion, the optimal approach is to apply the diagnostic approaches based on the analysis of information about light-scattering (the use of Raman spectroscopy in vivo, as a diagnostic aid for discovering incipient caries [ 70 , 71 , 72 ]) and autofluorescent properties of the intact and affected dental tissue. Al-Obaidi et al [ 52 ] have shown that comparing the data from the fluorescence spectra (shift of the signal to the red spectral range) and confocal Raman microscopy (determination of the value for the ratio of the Raman signal for the mineral phosphate band 𝜈 2 at ~430 cm −1 and the organic matrix at ~2931 cm −1 ) enabled understanding of the changes in the chemical composition of the enamel and the separation of the demineralised and intact parts of the enamel on the surface of tooth enamel.…”

The emerging applications and advancements of Raman spectroscopy in pediatric cancers

“…Raman spectroscopy (RS) is an optical spectroscopic technique using different frequencies of scattering light to characterize biological specimens ( 14 , 15 ). It probes the vibrational modes related to chemical bonds in a sample and obtains the “Raman Spectrum”, which is a unique spectral fingerprint of the sample ( 16 , 17 ).…”

“…Different samples possess their chemical compositions, which give RS the ability to reveal changes in the components and structure of target samples in a non-destructive manner ( 18 ). It provides deep insights into biological activities, offering a new angle to analyze diseases and assisting in diagnosis, treatment, and prognostic evaluation ( 15 , 19 ). In fact, vibrational spectroscopy has been quite active over the past two decades.…”