Assessment of tissue oxygenation of periodontal inflammation in smokers using optical spectroscopy.

BACKGROUND: We have recently developed a periodontal diagnostic tool that was validated in non-smokers with periodontitis. Tobacco smoking is a recognized risk factor for periodontal diseases that can mask gingival bleeding and lead to a false negative diagnosis. Therefore, the purpose of current study is to further validate this instrument in smokers with periodontal diseases. METHODS: Using a portable optical near-infrared spectrometer, optical spectra were obtained, processed and evaluated from healthy (n = 108), gingivitis (n = 100), and periodontitis (n = 79) sites of 54 systemically healthy smokers. A modified Beer-Lambert unmixing model that incorporates a non-parametric scattering loss function was used to determine the relative contribution of deoxygenated haemoglobin (Hb) and oxygenated haemoglobin (HbO2 ) to the overall spectrum. The balance between tissue oxygen delivery and utilization in periodontal tissues was then assessed. RESULTS: Tissue oxygen saturation was significantly decreased in the gingivitis (p = 0.016) and periodontitis (p = 0.007) sites, compared to the healthy sites. There was a trend towards increased concentration of Hb and decreased concentration of HbO2 from healthy to diseased sites, without statistical significance (p > 0.05). CONCLUSIONS: Optical spectroscopy can determine tissue oxygenation profiles of healthy and diseased sites in smokers. The spectral profile of periodontal sites in smokers generally resembles those from non-smoking patients.

Assessment of tissue oxygenation of periodontal inflammation in patients with coronary artery diseases using optical spectroscopy.

BACKGROUND: We have recently developed a non-invasive periodontal diagnostic tool that was validated in periodontitis patients without systemic disorders like coronary artery disease (CAD). The purpose of present study is to verify whether this optical instrument can also be used in periodontitis patients with CAD. METHODS: A total of 62 periodontitis patients with CAD were recruited along with a control group consisting of 59 age and gender matched periodontitis volunteers without systemic disorders. Using a portable optical near-infrared spectrometer, optical spectra were obtained, processed and evaluated from the two groups. A modified Beer-Lambert unmixing model that incorporates a nonparametric scattering loss function was used to determine the relative contribution of deoxygenated hemoglobin (Hb) and oxygenated hemoglobin (HbO2) to the overall spectrum. The balance between tissue oxygen delivery and utilization in periodontal tissues was then assessed. RESULTS: Tissue oxygen saturation was significantly decreased in the periodontitis sites (p < 0.01), compared to the healthy sites in those individuals with CAD. There was a trend towards increased concentration of Hb and decreased concentration of HbO2 from healthy to diseased sites, without statistical significance (p > 0.05). No statistical differences were found in tissue oxygen saturation between the CAD and control groups either in periodontal healthy or inflammatory sites. CONCLUSION: This study supports the hypothesis that optical spectroscopy can determine the periodontal inflammation in patients with certain systemic disorders like CAD. And the overall periodontal oxygenation profiles in CAD patients resemble those in non-CAD individuals either in healthy or inflammatory sites.

Comparing the efficacy and safety of high-voltage and standard-voltage pulsed radiofrequency for the treatment of postherpetic neuralgia: A pooled analysis from randomized controlled trials.

Postherpetic neuralgia (PHN) is one of the most common and serious complications of herpes zoster infection. Pulsed radiofrequency (PRF) therapy has emerged to be a neuromodulation technique for the treatment of PHN. Two therapeutic options are available for PRF, including high-voltage and standard-voltage PRF. Some studies suggested that the former one had better clinical efficacy than the latter one. For the first time, this pooled analysis compared the efficacy and safety of these two surgeries for the treatment of PHN. Five commonly used databases were applied to identify the eligible studies. This study was registered on the PROSPERO (ID: CRD42023460236), which provided more relevant information. Finally, four randomized controlled trials (RCTs) with 285 participants were included. The combined odds ratios (OR) showed that high-voltage PRF exhibited a significantly higher treatment efficiency than the standard PRF (OR = 1.4, 95%CI: 1.16 to 1.69, P < 0.001). Additionally, the visual analogue scale (VAS) in the high-voltage PRF group was significantly lower than that of the standard PRF group at one week (SMD = -0.776, 95%CI: -1.408 to -0.145, P = 0.016), one month (SMD = -0.544, 95%CI: -0.907 to -0.180, P = 0.003), and three months (SMD = -1.096, 95%CI: -1.504 to -0.687, P < 0.001) after treatment, particularly at the three months after surgery. However, the VAS was comparable between the two groups (SMD = -0.94, 95%CI: -1.985 to 0.104, P = 0.077). Patients who underwent high-voltage PRF did not have a significantly higher incidence of adverse events than those with standard PRF (OR = 1.56, 95%CI: 0.78 to 3.13, P = 0.208). In summary, the current study revealed that high-voltage PRF is superior to standard-voltage PRF in improving analgesic efficacy in patients with PHN. Additionally, it does not increase the incidence of treatment-related adverse effects. Further studies are still warranted to determine the optimal voltage and duration of PRF treatment for patients with PHN.

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.

Assessment of local hemodynamics in periodontal inflammation using optical spectroscopy.

BACKGROUND: Among the newly emerging diagnostic approaches for periodontitis, optical spectroscopy is a promising complementary diagnostic tool. The objective of this study is to verify the reproducibility of this method at a geographically distinct location (Suzhou, China) to a broader patient population using similar instrumentation to that in a previous report. METHODS: Using a portable optical near-infrared spectrometer, optical spectra were obtained, processed, and evaluated from healthy (n = 62), gingivitis (n = 98), and periodontitis (n = 47) sites from a total of 51 patients. A modified Beer-Lambert unmixing model that incorporates a non-parametric scattering loss function was used to determine the relative contribution of oxyhemoglobin and deoxyhemoglobin to the overall spectrum. The balance between tissue oxygen delivery and oxygen use in periodontal tissues was then assessed. RESULTS: Tissue oxygenation decreased significantly from healthy sites to sites with gingivitis (P <0.01) and between gingivitis and periodontitis (P = 0.015). This is largely caused by a significant increase in deoxyhemoglobin between normal and gingivitis (P <0.01) and a concomitant decrease in oxyhemoglobin between gingivitis and periodontitis (P = 0.02). CONCLUSION: This study supports previous findings that tissue oxygenation as measured by optical spectroscopy is significantly decreased in periodontitis and that optical spectroscopy can simultaneously determine multiple inflammatory indices related to periodontal disease directly in gingival tissues in vivo.

An update on novel non-invasive approaches for periodontal diagnosis.

For decades there has been an ongoing search for clinically acceptable methods for the accurate, non-invasive diagnosis and prognosis of periodontitis. There are several well-known inherent drawbacks with current clinical procedures. The purpose of this review is to summarize some of the newly emerging diagnostic approaches, namely, infrared spectroscopy, optical coherence tomography (OCT), and ultrasound. The history and attractive features of these new approaches are briefly illustrated, and the interesting and significant inventions related to dental applications are discussed. The particularly attractive aspects for the dental community are that some of these methods are totally non-invasive, do not impose any discomforts to the patients during the procedure, and require no tissue to be extracted. For instance, multiple inflammatory indices withdrawn from near infrared spectra have the potential to identify early signs of inflammation leading to tissue breakdown. Morphologically, some other non-invasive imaging modalities, such as OCT and ultrasound, could be employed to accurately measure probing depths and assess the status of periodontal attachment, the front-line of disease progression. Given that these methods reflect a completely different assessment of periodontal inflammation, if clinically validated, these methods could either replace traditional clinical examinations for the diagnosis of periodontitis or at least serve as attractive complementary diagnostic tools. However, the potential of these techniques should be interpreted more cautiously given the multifactorial character of periodontal disease. In addition to these novel tools in the field of periodontal inflammatory diseases, other alternative modalities like microbiologic and genetic approaches are only briefly mentioned in this review because they have been thoroughly discussed in other comprehensive reviews.