Periodontitis-specific molecular signatures in gingival crevicular fluid

A Study of the Association between Primary Oral Pathologies (Dental Caries and Periodontal Diseases) Using Synchrotron Molecular FTIR Spectroscopy in View of the Patient's Personalized Clinical Picture (Demographics and Anamnesis)

In this exploratory study, we searched for associations between the two most common diseases of the oral cavity-dental caries and periodontal diseases-taking into account additional factors, such as personalized clinical pictures (the individual risk factors of the patient), based on the method of a multivariate data analysis of the molecular changes in the composition of human gingival crevicular fluid (GCF). For this purpose, a set of synchrotron Fourier-transform infrared spectroscopy (FTIR) spectra of gingival crevicular fluid samples from patients with different demographics, levels of dental caries development and periodontal diseases, and the presence/absence of concomitant chronic diseases were obtained and analyzed. Using a set of techniques (v-, F-, Chi-square tests; a principal component analysis (PCA); and the hierarchical clustering of principal components (HCPCs)) implemented in the R package FactoMineR allowed us to assess the relationship between the principal components (PCs) and characteristics of the respondents. By identifying the features (vibrational modes in the FTIR spectra) that contribute most to the differentiation of the spectral dataset, and by taking into account the interrelationships between the patients' characteristics, we were able to match specific biological markers (specific molecular groups) to the two factors of interest-two types of oral pathologies. The results obtained show that the observed changes in the quantitative and qualitative composition of the modes in the infrared (IR) spectra of the GCF samples from patients with different dental caries developments and periodontal diseases present confirm the difficulty of identifying patient-specific spectral information. At the same time, different periodontal pathologies are more closely associated with other characteristics of the patients than the level of their caries development. The multivariate analysis performed on the spectral dataset indicates the need to take into account not only the co-occurrence of oral diseases, but also some other factors. The lack of this consideration (typical in lots of studies in this area) may lead to misinterpretations and consequently to a loss of data when searching for biological markers of certain oral diseases.

Infrared spectroscopy for fast screening of diabetes and periodontitis

SIGNIFICANCE

FT-IR is an important and emerging tool, providing information related to the biochemical composition of biofluids. It is important to demonstrate that there is an efficacy in separating healthy and diseased groups, helping to establish FT-IR uses as fast screening tool.

AIM

Via saliva diagnosis evaluate the accuracy of FT-IR associate with machine learning model for classification among healthy (control group), diabetic (D) and periodontitis (P) patients and the association of both diseases (DP).

APPROACH

Eighty patients diagnosed with diabetes and periodontitis through conventional methods were recruited and allocated in one of the four groups. Saliva samples were collected from participants of each group (n = 20) and were processed using Bruker Alpha II spectrometer in a FT-IR spectral fingerprint region between 600 and-1800 cm-1, followed by data preprocessing and analysis using machine learning tools.

RESULTS

Various FTI-R peaks were detectable and attributed to specific vibrational modes, which were classified based on confusion matrices showed in paired groups. The highest true positive rates (TPR) appeared between groups C vs D (93.5 % ± 2.7 %), groups C vs. DP (89.2 % ± 4.1 %), and groups D and P (90.4 % ± 3.2 %). However, P vs DP presented higher TPR for DP (84.1 % ±3.1 %) while D vs. DP the highest rate for DP was 81.7 % ± 4.3 %. Analyzing all groups together, the TPR decreased.

CONCLUSION

The system used is portable and robust and can be widely used in clinical environments and hospitals as a new diagnostic technique. Studies in our groups are being conducted to solidify and expand data analysis methods with friendly language for healthcare professionals. It was possible to classify healthy patients in a range of 78-93 % of accuracy. Range over 80 % of accuracy between periodontitis and diabetes were observed. A general classification model with lower TPR instead of a pairwise classification would only have advantages in scenarios where no prior patient information is available regarding diabetes and periodontitis status.

Two-trace two-dimensional correlation spectra (2T2D-COS) analysis using FTIR spectra to monitor the immune response by COVID-19

There is a growing trend in using saliva for SARS-CoV-2 detection with reasonable accuracy. We have studied the responses of IgA, IgG, and IgM in human saliva by directly comparing disease with control analyzing two-trace two-dimensional correlation spectra (2T2D-COS) employing Fourier transform infrared (FTIR) spectra. It explores the molecular-level variation between control and COVID-19 saliva samples. The advantage of 2T2D spectra is that it helps in discriminating remarkably subtle features between two simple pairs of spectra. It gives spectral information from highly overlapped bands associated with different systems. The clinical findings from 2T2D show the decrease of IgG and IgM salivary antibodies in the 50, 60, 65, and 75-years COVID-19 samples. Among the various COVID-19 populations studied the female 30-years group reveals defense mechanisms exhibited by IgM and IgA. Lipids and fatty acids decrease, resulting in lipid oxidation due to the SARS-CoV-2 in the samples studied. Study shows salivary thiocyanate plays defense against SARS-CoV-2 in the male population in 25 and 35 age groups. The receiver operation characteristics statistical method shows a sensitivity of 98% and a specificity of 94% for the samples studied. The measure of accuracy computed as F score and G score has a high value, supporting our study's validation. Thus, 2T2D-COS analysis can potentially monitor the progression of immunoglobulin's response function to COVID-19 with reasonable accuracy, which could help diagnose clinical trials. KEY MESSAGES: The molecular profile of salivary antibodies is well resolved and identified from 2T2D-COS FTIR spectra. The IgG antibody plays a significant role in the defense mechanism against SARS-CoV-2 in 25-40 years. 2T2D-COS reveals the absence of salivary thiocyanate in the 40-75 years COVID-19 population. The receiver operation characteristic (ROC) analysis validates our study with high sensitivity and specificity.

Unlocking the Diagnostic Potential of Saliva: A Comprehensive Review of Infrared Spectroscopy and Its Applications in Salivary Analysis

Infrared (IR) spectroscopy is a noninvasive and rapid analytical technique that provides information on the chemical composition, structure, and conformation of biomolecules in saliva. This technique has been widely used to analyze salivary biomolecules, owing to its label-free advantages. Saliva contains a complex mixture of biomolecules including water, electrolytes, lipids, carbohydrates, proteins, and nucleic acids which are potential biomarkers for several diseases. IR spectroscopy has shown great promise for the diagnosis and monitoring of diseases such as dental caries, periodontitis, infectious diseases, cancer, diabetes mellitus, and chronic kidney disease, as well as for drug monitoring. Recent advancements in IR spectroscopy, such as Fourier-transform infrared (FTIR) spectroscopy and attenuated total reflectance (ATR) spectroscopy, have further enhanced its utility in salivary analysis. FTIR spectroscopy enables the collection of a complete IR spectrum of the sample, whereas ATR spectroscopy enables the analysis of samples in their native form, without the need for sample preparation. With the development of standardized protocols for sample collection and analysis and further advancements in IR spectroscopy, the potential for salivary diagnostics using IR spectroscopy is vast.

μ-FTIR, μ-Raman, and SERS Analysis of Amide I Spectral Region in Oral Biofluid Samples during Orthodontic Treatment

Gingival crevicular fluid (GCF) is a site-specific exudate deriving from the epithelium lining of the gingival sulcus. GCF analysis provides a simple and noninvasive diagnostic procedure to follow-up periodontal and bone remodeling in response to diseases or mechanical stimuli such as orthodontic tooth movement (OTM). In recent years, the use of vibrational spectroscopies such as Fourier Transform Infrared and Raman microspectroscopy and Surface-Enhanced Raman spectroscopy contributed to characterizing changes in GCF during fixed orthodontic treatment. Amide I band plays a relevant role in the analysis of these changes. The aim of this study was to investigate the spectroscopy response of Amide I depending on the OTM process duration. A model based on Gaussian-Lorentzian curves was used to analyze the infrared spectra, while only Lorentzian functions were used for Raman and SERS spectra. Changes induced by the OTM process in subcomponents of the Amide I band were determined and ascribed to secondary structure modification occurring in proteins. The vibrational spectroscopies allow us to efficiently monitor the effects of the orthodontic force application, thus gaining increasing attention as tools for individual patient personalization in clinical practice.

Oral lichen planus identification by mid-infrared spectroscopy of oral biofluids: A case-control study

BACKGROUND AND AIMS

This study aims to access the effectiveness of mid-infrared (MIR) spectroscopy on the identification of the reticular form of OLP, following the assessment of gingival crevicular fluid (GCF) and oral mucosa transudate (OMT).

MATERIAL AND METHODS

The trial follows a case-control design. Samples were characterized through MIR spectroscopy and chemometric tools were applied to distinguish between case and control participants, further identifying the spectral regions with the highest contribution to the developed models.

RESULTS

MIR spectroscopy was capable to discriminate between OLP patients and controls with 95.1% and 85.4% of correct predictions, regarding GCF and OMT samples, respectively. Additionally, the spectral regions mostly contributing to the successful prediction were identified, and possibly related with the distinctive presence of amino acids/proteins and oxidative stress mediators in oral biofluids, supporting the role of the immune-inflammatory activation on OLP etiology and disease course.

CONCLUSION

MIR spectroscopy analysis of GCF and OMT may be regarded as an innovative, non-invasive, low cost and sensitive technique, contributing to the identification of the reticular from of OLP.

Longitudinal evaluation of clinical, spectral and tissue degradation biomarkers in progression of periodontitis among cigarette and electronic cigarette smokers

OBJECTIVES

To longitudinally evaluate the periodontal parameters and MMP-8 and CTX (C-terminal crosslinked telopeptide of type I collagen) levels from diseased and healthy sites from cigarette and electronic cigarette (e-cig) smokers and characterize the gingival crevicular fluid (GCF) samples using Raman spectroscopy In addition, to longitudinally determine if MMP-8 and CTX are predictive factors for attachment loss in periodontitis sites.

METHODS

Sixty periodontally healthy and 60 periodontitis/diseased sites from 30 e-cig and 30 cigarette smokers were monitored at baseline, 3 months, and 6-months. GCF was sampled to study the MMP-8 and CTX concentrations using enzyme-linked immunosorbent assay. Infra-red absorption spectra of GCF were acquired at all time points and processed to identify key functional groups.

RESULTS

A significantly increased attachment loss was observed at 6 months for both smokers when compared with baseline (p < 0.01). This difference was significantly high for cigarette smokers compared with e-cig users (p < 0.01). MMP-8, CTX, smoking pack-years were significantly correlated with probing depth and clinical attachment loss among both e-cig and cigarette smokers. For MMP-8 and CTX, the periodontitis sites showed a statistically significant difference between e-cig and cigarette smokers at both 3- and 6 months follow-up. From baseline to 6 months follow-up, periodontitis sites from both groups showed higher spectral band intensities with deconvulations and Raman shifts for Amide I and Amide II peaks.

CONCLUSION

Cigarette smokers showed higher periodontal worsening than e-cig smokers. Smoking, MMP-8, CTX are prognostic factors for clinical attachment loss in cigarette and e-cig smokers.

CLINICAL SIGNIFICANCE

Data for Raman scattering and spectral information identifying collagen degradation among e-cig and cigarette smokers have been analyzed. This type of analysis proves a robust diagnostic and prognostic tool for periodontal diseases. Smoking, MMP-8, and CTX are prognostic factors for clinical attachment loss in cigarette and e-cig smokers.

Application of Vibrational Spectroscopies in the Qualitative Analysis of Gingival Crevicular Fluid and Periodontal Ligament during Orthodontic Tooth Movement

Optical vibrational techniques show a high potentiality in many biomedical fields for their characteristics of high sensitivity in revealing detailed information on composition, structure, and molecular interaction with reduced analysis time. In the last years, we have used these techniques for investigating gingival crevicular fluid (GCF) and periodontal ligament (PDL) during orthodontic tooth treatment. The analysis with Raman and infrared signals of GCF and PDL samples highlighted that different days of orthodontic force application causes modifications in the molecular secondary structure at specific wavenumbers related to the Amide I, Amide III, CH deformation, and CH₃/CH₂. In the present review, we report the most relevant results and a brief description of the experimental techniques and data analysis procedure in order to evidence that the vibrational spectroscopies could be a potential useful tool for an immediate monitoring of the individual patient's response to the orthodontic tooth movement, aiming to more personalized treatment reducing any side effects.

[Spectroscopic studies of the molecular composition of the dentinal and gingival fluids and their diagnostic potential for preventive screening of dentin caries]

PURPOSE OF THE STUDY

The aim of the work is a spectroscopic investigation and comparison of the molecular composition of dentine and gingival fluids as well as of their diagnostic potential for the preventive screening of dentin caries.

MATERIAL AND METHODS

Applying infrared spectroscopy including synchrotron radiation the samples of biological fluids taken from the oral cavity (dentine fluid, fluid from the gingival sulcus and blood) were studied for the patients with the progressive dentine caries. The part of this research was undertaken with the infrared microspectroscopy beamline at the Australian Synchrotron.

RESULTS

Dentine and gingival fluids were shown to have no less complicated composition than the blood serum. Having all this in mind, in spite that these two fluids are derivatives of the blood serum, and a majority of the molecular groups observed in all of the three fluids can be detected in their IR-spectra, it follows that there is a number of signature modes that are in fact present in the IR spectra of only dentine and gingival fluids. This fact indicates at the molecular exchange between them under certain conditions. It means the high diagnostic potential in the study of the pathologic processes occurring in the oral fluid of a human. We have observed and fixed an increase of thiocyanates and esters in the samples of both dentine and gingival fluids under the development of dentin caries.

CONCLUSION

Utilization of the gingival fluid for screening taking into account that its sampling is not such a complicated challenge as dentine fluid sampling will promote a transition to the personalized medicine, the development of high-technology healthcare and technology of the health preservation as a whole.

The Role of DNA Methylation and Histone Modification in Periodontal Disease: A Systematic Review

Despite a number of reports in the literature on the role of epigenetic mechanisms in periodontal disease, a thorough assessment of the published studies is warranted to better comprehend the evidence on the relationship between epigenetic changes and periodontal disease and its treatment. Therefore, the aim of this systematic review is to identify and synthesize the evidence for an association between DNA methylation/histone modification and periodontal disease and its treatment in human adults. A systematic search was independently conducted to identify articles meeting the inclusion criteria. DNA methylation and histone modifications associated with periodontal diseases, gene expression, epigenetic changes after periodontal therapy, and the association between epigenetics and clinical parameters were evaluated. Sixteen studies were identified. All included studies examined DNA modifications in relation to periodontitis, and none of the studies examined histone modifications. Substantial variation regarding the reporting of sample sizes and patient characteristics, statistical analyses, and methodology, was found. There was some evidence, albeit inconsistent, for an association between DNA methylation and periodontal disease. IL6, IL6R, IFNG, PTGS2, SOCS1, and TNF were identified as candidate genes that have been assessed for DNA methylation in periodontitis. While several included studies found associations between methylation levels and periodontal disease risk, there is insufficient evidence to support or refute an association between DNA methylation and periodontal disease/therapy in human adults. Further research must be conducted to identify reproducible epigenetic markers and determine the extent to which DNA methylation can be applied as a clinical biomarker.

Salivary Fingerprinting of Periodontal Disease by Infrared-ATR Spectroscopy

PURPOSE

Periodontal diseases, the most common chronic inflammatory diseases in humans, do not only affect tooth-supporting tissues but also other body parts by contributing to the development of life-threatening conditions. Since currently available diagnostic methods in periodontics lack the ability to identify patients at high risk for periodontal disease progression, development of innovative, non-invasive, rapid detection methods for diagnosing periodontal diseases is needed. This study aims to assess the potential of infrared attenuated total reflection (IR-ATR) spectroscopy to detect differences in composition of saliva supernatant in non-periodontitis individuals (control) and patients with generalized aggressive periodontitis (G-AgP).

EXPERIMENTAL DESIGN

IR-ATR is performed with a wavelength interval from 1230 to 1180 cm^-1 , analyzed with a simple subtraction in absorbance data.

RESULTS

Ten samples show in the analysis of variance of the two data sets a true difference (99.8%). A principal component analysis (PCA) is able to discriminate between G-AgP and control groups.

CONCLUSION AND CLINICAL RELEVANCE

This study demonstrates for the first time that IR-ATR spectroscopy is a promising tool for the analysis of saliva supernatant for the diagnosis of periodontitis, and potentially other periodontal conditions. IR-ATR spectroscopy holds the potential to be miniaturized and utilized as a non-invasive screening test.

Spectroscopic signature of the pathological processes of carious dentine based on FTIR investigations of the oral biological fluids

The aim of our work is to find a spectroscopic signature of the pathological processes of carious dentine based on the investigations of the molecular composition of the oral biological fluids with the use of FTIR synchrotron techniques. This complex analysis of the obtained data shows that a number of signatures are present only in the spectra of dentine and gingival fluids from the patients developing caries of the deep dentine tissues. The detected features and complex analysis of the quantitative and qualitative data representing signatures of the development of oral cavity pathologies can enhance the quality of dental screening.

Differentiation of Chronic and Aggressive Periodontitis by FTIR Spectroscopy

Without longitudinal clinical data, it is difficult to differentiate some cases of chronic periodontitis (CP) and aggressive periodontitis (AgP). Furthermore, both forms of disease are exacerbated by tobacco use. Therefore, this cross-sectional study was planned, primarily, to determine the ability of Fourier-transform infrared (FTIR) spectroscopy to distinguish CP and AgP patients by analysis of human saliva samples and, secondarily, to assess the potential confounding influence of smoking on discriminating disease-specific spectral signatures. FTIR spectra were collected from patients with a clinical diagnosis of CP (n = 18; 7 smokers) or AgP (n = 23; 9 smokers). Self-reported smoking status, which may be unreliable, was confirmed by salivary cotinine analysis. Spectral band area analysis and hierarchical cluster analyses were performed to clarify if the 2 periodontitis groups as well as smoker and nonsmoker patients could be differentiated from each other. Significant variations in lipid, amino acid, lactic acid, and nucleic acid content were found between nonsmoker CP and AgP groups. Although significantly lower lipid, phospholipid, protein, amino acid, lactic acid, and nucleic acid content was noted in the smoker AgP group compared with the nonsmoker AgP group, in the CP group, phospholipid, protein, amino acid, and lactic acid content was significantly lower for smokers compared with the nonsmokers. Based on these variations, nonsmoker CP and AgP patients were discriminated from each other with high sensitivity and specificity. Successful differentiation was also obtained for the smoker CP and AgP groups. Thiocyanate levels successfully differentiated smokers from nonsmokers, irrespective of periodontal status, with 100% accuracy. Differentiation of AgP and CP forms, concomitant with determination of smoking status, may allow the dental health professional to tailor treatment accordingly.

Fourier Transform Infrared Spectroscopy and Photoacoustic Spectroscopy for Saliva Analysis

Saliva provides a valuable tool for assessing oral and systemic diseases, but concentrations of salivary components are very small, calling the need for precise analysis methods. In this work, Fourier transform infrared (FT-IR) spectroscopy using transmission and photoacoustic (PA) modes were compared for quantitative analysis of saliva. The performance of these techniques was compared with a calibration series. The linearity of spectrum output was verified by using albumin-thiocyanate (SCN(-)) solution at different SCN(-) concentrations. Saliva samples used as a comparison were obtained from healthy subjects. Saliva droplets of 15 µL were applied on the silicon sample substrate, 6 drops for each specimen, and dried at 37 ℃ overnight. The measurements were carried out using an FT-IR spectrometer in conjunction with an accessory unit for PA measurements. The findings with both transmission and PA modes mirror each other. The major bands presented were 1500-1750 cm(-1) for proteins and 1050-1200 cm(-1) for carbohydrates. In addition, the distinct spectral band at 2050 cm(-1) derives from SCN(-) anions, which is converted by salivary peroxidases to hypothiocyanate (OSCN(-)). The correlation between the spectroscopic data with SCN(-) concentration (r > 0.990 for transmission and r = 0.967 for PA mode) was found to be significant (P < 0.01), thus promising to be utilized in future applications.

Evaluation of Salivary Levels of Pyridinoline Cross Linked Carboxyterminal Telopeptide of Type I Collagen (ICTP) in Periodontal Health and Disease

BACKGROUND

Traditional parameters (Pocket depth, bleeding on probing, clinical attachment loss, radiographic findings) have been used for a long time for the assessment of periodontal disease conditions. However, these parameters only indicate towards the periodontal damage that has already taken place but do not give any idea regarding the current status of the periodontal health or disease. Hence, the present study is aimed at evaluating the concentration of the bone biomarker ICTP in saliva, which can give a better real time assessment of periodontal health and disease.

MATERIALS AND METHODS

Forty three patients were selected and divided into three groups based on the recorded clinical parameters of probing pocket depth, attachment loss and bleeding on probing. Group I (Healthy, n = 11), Group II (Gingivitis, n = 17), Group III (Periodontitis. n = 15). Salivary samples were collected before scaling and root planning to avoid contamination by blood. ICTP levels were evaluated in the salivary samples by using enzyme linked immunosorbent assay (ELISA).

STATISTICAL ANALYSIS USED

Kruskal Wallis test was used to compare the mean ICTP level of the three groups.

RESULTS

ICTP was detected in all the samples. Highest mean ICTP concentrations in saliva were obtained for group III (periodontitis group) and the lowest mean ICTP concentrations were seen in group I (healthy group). This suggests that the level of ICTP in saliva increases proportionally from periodontal health to diseased conditions (gingivitis & periodontitis).

CONCLUSION

There is a substantial increase in the salivary concentration of ICTP in chronic periodontitis patients than in gingivitis and healthy patients. Salivary ICTP levels were the maximum in chronic periodontitis patients followed by gingivitis patients and the least in healthy individuals. ICTP may be considered as a biomarker in periodontal disease progression.

Biochemical characterization of human gingival crevicular fluid during orthodontic tooth movement using Raman spectroscopy

This study used Raman spectroscopy to report the first human gingival crevicular fluid (GCF) biochemical characterization during the early phase of orthodontic tooth movement. This technique allows for label-free and noninvasive biochemical change monitoring in GCF during orthodontic tooth movement. Ten orthodontic patients (20.8 ± 2.5 years) participated in the study. GCF samples were obtained before (baseline, 0 days) and during orthodontic treatment at 1, 7 and 28 days. For Raman spectroscopic measurement, GCF samples (5 µl) were deposited onto a gold-coated substrate, then dried at room temperature. Raman spectra GCF analysis during orthodontic treatment indicated that the hydroxyapatite to primarily collagen-dominated matrix band (phosphate 984 cm(-1)/amide I 1667 cm(-1)) intensity ratio decreased at day 7 (P < 0.05). The carbonate apatite to hydroxyapatite ratio (carbonate 1088 cm(-1)/phosphate 984 cm(-1)) was significantly higher on day 7 compared to day 0 (P < 0.05). These results indicate that demineralization occurs during the alveolar bone remodeling process. We also found notable peak shifts in the amide I range during orthodontic tooth movement. The 1658 cm(-1) in baseline red shifted to 1667 cm(-1) at orthodontic treatment day 7. Curve fitting in the amide I (1615-1725 cm(-1)) range demonstrated that increased random coil conformation was accompanied by a decrease in β-sheet structure during orthodontic tooth movement. Thus, we suggest Raman spectroscopy could be used for label-free, non-invasive GCF quality assessment during orthodontic tooth movement. Furthermore, this method may prove to be a powerful diagnostic and prognostic tool for monitoring orthodontic tooth movement in a clinical setting.

Diabetes-associated periodontitis molecular features in infrared spectra of gingival crevicular fluid

BACKGROUND

It has been established previously that infrared spectroscopy (IRS) can be used to identify periodontitis-specific molecular signatures in gingival crevicular fluid (GCF) and to confirm clinical diagnoses. This follow-up study is designed to assess whether this novel technique is also able to differentiate diseased from healthy sites in patients with diabetes mellitus (DM) by analyzing the molecular fingerprints embedded in the GCF.

METHODS

A total of 65 patients with DM with moderate-to-severe chronic periodontitis (CP) was recruited, and 15 individuals without DM (65 sites) without periodontal diseases were used as control. Clinical examination and GCF samples were taken from a total of 351 sites, including periodontitis (109), gingivitis (115), and healthy (127) sites. Corresponding absorption spectra of GCF samples were acquired and processed, and the relative contributions of key functional groups in the infrared spectra were identified and analyzed. The qualitative assessment of clinical relevance of these GCF spectra was interpreted with multivariate statistical analysis: linear discriminant analysis (LDA).

RESULTS

Spectral analysis revealed several molecular signatures representing vibrations in protein (amide I and II), lipid ester, and sugar moieties in the GCF of patients with DM with CP and non-DM controls. The diagnostic accuracy for distinction between healthy and CP sites in patients with DM determined by LDA of GCF spectra was 95.3% for the training set of samples and 87.5% for the validation set. Additional LDA of GCF spectra from healthy sites of non-DM controls and patients with DM revealed 100% diagnostic accuracy for the training set and 86.7% for the validation set. The regions robotically selected by LDA for the two analyses were slightly different in that first LDA identified major regions clustered with the side chain vibrations originating from protein and DNA contents, whereas the second was predominantly the glycation and protein components.

CONCLUSION

IRS is a feasible method to differentiate disease-specific molecular signatures in GCF in the presence of DM and to generate a complex biochemical profile of GCF to identify DM-specific spectral features.

New developments in tools for periodontal diagnosis

OBJECTIVES

For decades there has been increasing focus on the development of clinically acceptable, more sensitive and specific methods for the accurate and non-invasive diagnosis and prognosis of periodontitis. There are several well-known inherent drawbacks to current clinical procedures. The purpose of this article is to summarise some of the newly emerging diagnostic approaches, namely: the ultrasonographic probe; cone-beam computed tomography; optical coherence tomography; optical spectroscopy, and proteome analysis.

RESULTS

These novel diagnostic tools complement one another and, together with conventional clinical and radiographic examination, are likely to provide more accurate methods of diagnosing periodontitis. However, these techniques are yet to be clinically validated and their potential interpreted.

CONCLUSIONS

For the clinician, the planning of therapy is probably the most critical and difficult step in the treatment of patients with periodontal disease. A new paradigm for periodontal diagnosis will certainly increase understanding of periodontal diseases, which may eventually optimise the predictability of treatment and improve the clinical management of patients with periodontal disease.

Contemporary concepts in the diagnosis of periodontal disease

Periodontitis is an inflammatory disease of bacterial origin that results in the progressive destruction of the tissues that support the teeth, specifically the gingiva, periodontal ligament, and alveolar bone. The diagnosis of periodontal disease currently relies almost exclusively on clinical parameters and traditional dental radiography. In this article, the authors review current diagnostic techniques and present new approaches and technologies that are being developed to improve assessment of this common condition.