Abstract
The study of oral disease progression, in relation to the accumulation of subgingival biofilm in gingivitis and periodontitis is limited, due to either the ability to monitor plaque in vitro. When compared, optical spectroscopic techniques offer advantages over traditional destructive or biofilm staining approaches, making it a suitable alternative for the analysis and continued development of three-dimensional structures. In this work, we have developed a confocal Raman spectroscopy analysis approach towards in vitro subgingival plaque models. The main objective of this study was to develop a method for differentiating multiple oral subgingival bacterial species in planktonic and biofilm conditions, using confocal Raman microscopy. Five common subgingival bacteria (Fusobacterium nucleatum, Streptococcus mutans, Veillonella dispar, Actinomyces naeslundii and Prevotella nigrescens) were used and differentiated using a 2-way orthogonal Partial Least Square with Discriminant Analysis (O2PLS-DA) for the collected spectral data. In addition to planktonic growth, mono-species biofilms cultured using the ‘Zürich Model’ were also analyzed. The developed method was successfully used to predict planktonic and mono-species biofilm species in a cross validation setup. The results show differences in the presence and absence of chemical bands within the Raman spectra. The O2PLS-DA model was able to successfully predict 100% of all tested planktonic samples and 90% of all mono-species biofilm samples. Using this approach we have shown that Confocal Raman microscopy can analyse and predict the identity of planktonic and mono-species biofilm species, thus enabling its potential as a technique to map oral multi-species biofilm models.
Highlights
While surface enhanced Raman scattering (SERS) remains promising in combination with Raman microscopy [13,29,30] with the potential for higher levels of discrimination spectra, this study focuses on the analysis of chemically un-modified biofilm samples
While many vibrational bands were similar in the acquired spectra, several unique bands could be assigned to each of the individual bacterial species (S1 Table) that have been assigned previously
Our results for Streptococci species are identical with the results from Berger et al [31], who previously identified components in S.mutans and S.sanguinis (Amide I at 1651 cm-1, C-H2 deformation at 1457 cm-1, C-N and C-C stretch at 1127 cm-1, phenylalanine at 1005 cm-1; Raman shift can appear due to the use of a different Raman analysis setup)
Summary
The main objective of this study was to develop a method for differentiating multiple oral subgingival bacterial species in planktonic and biofilm conditions, using confocal Raman microscopy. The purpose of this study is to lay the groundwork for using CRM in in-vitro research for subgingival biofilm models with the analysis of different oral subgingival species and its application to artificial subgingival mono-species biofilm models
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
