Micro-Raman spectroscopy during orthodontic tooth movement: Follow-up of gingival status

Micro-Raman spectroscopy (μ-RS) represents an appealing technique in dentistry, allowing the in-vitro detection of analytic structure and molecular composition changes of dental and oral cavity tissues. The gingival crevicular fluid (GCF) is a site-specific inflammatory exudate deriving from the epithelium lining of the gingival sulcus. The GCF analysis is useful in monitoring the factors related to the periodontal changes in response to diseases or mechanical stimuli. Therefore, the analysis of the GCF provides a simple and noninvasive diagnostic procedure to follow-up the periodontal ligament and bone remodeling during the orthodontic tooth movement. In this study, the potentiality of visible light μ-RS to evaluate GCF composition changes in the periodontium due to orthodontic forces was assessed. Sterile paper cones impregnated with GCF were collected from patients before and during an orthodontic treatment with fixed appliances and analyzed by μ-RS. A suitable numerical treatment based on wavelet-based algorithms was performed in order to eliminate the contribution of substrate and background signals on spectral data. The preliminary results showed changes in the secondary structure of Amide I band and an increase of carotenoid content in GCF during the orthodontic treatment.