Speed Up Monitoring Orthodontic Treatments by Using Gingival Crevicular Fluid FT-IR Spectroscopy in ATR Geometry

Gingival crevicular fluid (GCF) is an exudate originating in the epithelium lining of the gingival sulcus. GCF analysis can represent a simple and noninvasive tool for monitoring periodontal and bone remodeling during the orthodontic tooth movement (OTM). Previous work has demonstrated that Fourier transform infrared (FT-IR) spectroscopy on GCF gives interesting information on the changes occurring in protein, lipid, and carbohydrate contents during orthodontic treatments. Consequently, FT-IR spectroscopy can be considered a useful tool for monitoring OTM in a clinical environment. To this aim, it is important to shorten the spectra acquisition times and optimize the data analysis procedures. In this article, a faster procedure for collecting GCF spectra has been adopted by exploiting the attenuated total reflection (ATR) contact sampling method, which allows the collection of good-quality infrared spectra with no sample preparation. In this case, the spectra have been directly acquired on the supports used for collecting GCF avoiding any time-consuming extraction procedure. Furthermore, to optimize the data analysis procedures, different methods have been applied and new biomarkers have been identified for promoting a robust and rapid characterization of GCF, allowing more personalized orthodontic treatment by reducing any side effects.