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

Association of Polymorphism with Periodontitis and Salivary Levels of Hypoxia-Inducible Factor-1α

OBJECTIVE

 This investigation aims to investigate the association between HIF-1α genetic polymorphism and periodontitis and examine and contrast the levels of HIF-1α present in the saliva of subjects afflicted with periodontitis and in the control group. Additionally, this study aims to establish diagnostic proficiency of this biomarker in distinguishing between periodontal health and disease.

MATERIALS AND METHODS

 This study entailed the collection of venous blood samples and unstimulated saliva samples from a total of 160 participants, encompassing 80 individuals diagnosed with periodontitis and 80 periodontitis-free individuals. The periodontal parameters were evaluated, involving the measurement of clinical attachment loss, the probing pocket depth, and the bleeding on probing percentage. Subsequently, genetic analysis of HIF-1α using polymerase chain reaction (PCR) technique, DNA sequencing, and enzyme-linked immunosorbent assays was conducted.

RESULTS

 The genetic analysis of 352 bp of the HIF-1α gene revealed the presence of 66 single-nucleotide polymorphisms (SNPs) in control samples, whereas 78 SNPs were found in periodontitis sample. The nucleotide A was replaced with a C nucleotide at position 207 of the amplified PCR fragments. The homozygous AA pattern was predominant in the control group, with significant differences between the two groups. In contrast, the homozygous CC pattern was more dominant in the periodontitis group, with significant differences between the two groups. The analysis of Hardy-Weinberg equilibrium for the comparison between the observed and the expected genotypes showed significant differences between the observed and the expected values in the control and periodontitis groups, as well as the total sample. The highest mean values of the measured periodontal parameters were found in the periodontitis group (clinical attachment loss = 4.759, probing pocket depth = 4.050, and bleeding on probing = 30.950) with statistically significant differences between the groups. The periodontitis group showed significantly higher salivary HIF-1α levels compared to control group (p < 0.001). Besides, HIF-1α is a good biomarker in distinguishing between periodontal health and periodontitis.

CONCLUSION

 rs1951795 SNP of HIF-1α has no significant impact on the progression of periodontitis and the salivary level HIF-1α. Periodontitis results in a notable elevation in HIF-1α salivary levels, with an outstanding diagnostic ability to distinguish between periodontitis and periodontal health.

Non-invasive assessment of periodontal inflammation by continuum-removal hemodynamic spectral indices

BACKGROUND

Hyperspectral techniques have aroused great interest in non-invasively measuring periodontal tissue hemodynamics. However, current studies mainly focused on three typical inflammation stages (healthy, gingivitis and periodontitis) and practical approaches for using optical spectroscopy for early and precisely detection of periodontal inflammation at finer disease stages have not been well studied.

METHODS

This study provided novel spectroscopic insights into periodontitis at different stages of disease, and developed six simple but physically meaning hemodynamic spectral indices (HSIs) including four spectral absorption depths of oxyhemoglobin ( D HbO 2 ), deoxyhemoglobin ( D Hb ), total hemoglobin ( t Hb ) and tissue water ( D water ), and two normalized difference indices of oxyhemoglobin( N D HbO 2 I ) and deoxyhemoglobin ( N D Hb I ) from continuum-removal spectra (400-1700 nm) of periodontal tissue collected from 47 systemically healthy subjects over different severities from healthy, gingivitis, slight, moderate to severe periodontitis for early and precision diagnostics of periodontitis. Typical statistical analyses were conducted to explore the effectiveness of the proposed HSIs.

RESULTS

D Hb and t Hb exerted significant increasing trends as inflammation progressed, whereas D HbO 2 exhibited significant difference (P < 0.05) from the healthy sites only at moderate and severe periodontitis and D water presented unstable sensitives to disease severity. By contrast, N D HbO 2 I and N D Hb I showed more steadily downward trends as severity increased, and demonstrated the highest correlations with clinical gold standard parameters. Particularly, the proposed normalized HSIs ( N D HbO 2 I and N D Hb I ) yielded high correlations of - 0.49 and - 0.44 with probing depth, respectively, far outperforming results achieved by previous studies. The performances of the HSIs were also confirmed using the periodontal therapy group.

CONCLUSIONS

These results indicated great potentials of combination optical spectroscopy and smart devices to non-invasively probe periodontitis at earlier stages using the simple and practical HSIs. Trial registration This study was retrospectively registered in the Chinese Clinical Trial Registry on October 24, 2021, and the clinical registration number is ChiCTR2100052306.

Evaluation of perfusion parameters of gingival inflammation using laser Doppler flowmetry and tissue spectrophotometry- a prospective comparative clinical study

BACKGROUND

The aim of this study was to determine the values of different perfusion parameters- such as oxygen saturation, the relative amount of hemoglobin, and blood flow- in healthy subjects compared to patients with gingivitis as a non-invasive measurement method.

METHODS

A total of 114 subjects were enrolled in this study and separated into subjects with gingivitis (50) and without gingivitis (64) based on clinical examination. Gingival perfusion was measured at 22 points in the maxilla and mandible using laser Doppler flowmetry and tissue spectrophotometry (LDF-TS) with the "oxygen to see" device. All patients underwent measurement of gingival perfusion, followed by the clinical evaluation (measurement of probing depths, evaluation of bleeding on probing, plaque level, and biotype). Perfusion parameters were compared between the groups, associations between the non-invasive and clinical measurements were analyzed, and theoretical optimal cut-off values for predicting gingivitis were calculated with receiver operating characteristics.

RESULTS

The mean oxygen saturation, mean relative amount of hemoglobin, and mean blood flow all significantly differed between the groups with and without gingivitis (p = 0.005, p < 0.001, and p < 0.001, respectively). The cut-off value for predicting gingivitis was > 40 AU (p < 0.001; sensitivity 0.90, specificity 0.67).

CONCLUSIONS

As a non-invasive method, LDF-TS can help determine gingival hyperemia. Flow values above 40 AU indicate a higher risk of hyperemia, which can be associated with inflammation. The LDF-TS method can be used for the objective evaluation of perfusion parameters during routine examinations and can signal the progression of hyperperfusion before any change in clinical parameters is observed.

TRIAL REGISTRATION

All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by the institutional Clinical Research Ethics Committee (Ethik-Kommission der Medizinischen Fakultät der RWTH Aachen, Decision Number 286/20) and retrospectively registered by the German Clinical Trials Register (File Number DRKS00024048, registered on the 15th of October 2021).

The association between periodontitis patients' chief complaints and the stage of periodontitis: A clinical retrospective study

OBJECTIVES

The purposes of this retrospective study were to investigate the prevalence of various periodontal chief complaints (pCCs) of patients, diagnosed with periodontitis, as well as to identify the association between pCCs and periodontal parameters or periodontitis staging according to AAP/EFP 2017 classification.

MATERIALS AND METHODS

Five hundred eighty-nine patients, applied to the clinic with pCCs, were screened. The demographic characteristics, smoking status, brushing behaviors, history of periodontal therapy, medical data, and periodontal parameters were obtained. A multinomial logistic regression analysis was performed to determine the most common pCCs and co-variables among the indicators of Stage III and IV periodontitis.

RESULTS

In Stage IV periodontitis, patients with pCC of mobility were observed the most (26.8%), and pCC of halitosis were the least (7.3%). Among all pCCs of patients, those with the pCC of gingival enlargement and tooth mobility had the highest percentage of sites with PPD ≥ 4 mm and CAL ≥ 5 mm, respectively (p < .001). According to regression analysis, those with pCC of gingival bleeding, recession and mobility were more likely to be in Stage IV than those in Stage I/II.

CONCLUSION

Among pCCs, only patients with pCCs of mobility, gingival recession and bleeding are related to periodontitis staging. Moreover, the extent of periodontal pockets in patients with pCC of gingival enlargement, and the extent of attachment loss in patients with pCC of mobility are greater than other patients.

CLINICAL RELEVANCE

New machine-learning technology models can be developed with the aim of classifying the patients based on their chief complaints, to support diagnosing the severity of periodontal diseases.

Tobacco smoking decreases clinical symptoms of gingivitis in patients with type 1 diabetes-a cross-sectional study

OBJECTIVE

Periodontal disease may develop on the background of microvascular complications of diabetes. However, some modifying factors, such as tobacco smoking, should be taken into consideration when assessing risk of development of chronic complications. The aim of the study was the clinical assessment of the periodontal status in patients with type 1 diabetes according to tobacco smoking.

SUBJECTS AND METHODS

A total of 362 subjects aged 29 (IQR 22-35) years, type 1 diabetes duration 12 (8-18) years, hemoglobin A1c, HbA1c 8.0 (7.2-9.1)% were included. We used Gingival Index, Approximal Plaque Index, and Sulcus Bleeding Index to assess periodontal health. Patients were divided into two subgroups according to current cigarette smoking.

RESULTS

No differences in age, diabetes duration, and chronic complications were found between subgroups. A better metabolic control of diabetes expressed by lower HbA1c (p = 0.00001) and triglyceride levels (p = 0.004) was shown in nonsmokers. Smokers presented significantly lower gingival bleeding, p = 0.009. HbA1c correlated with API in study group (Rs = 0.16; p = 0.002) and in nonsmokers subgroup (Rs = 0.2;p = 0.004), however, not in smoker's subgroup. In multivariable regression analysis, smoking cigarettes (β = -0.26; p = 0.0002), hs-CRP (β = 0.15; p = 0.03) and age (β = -0.19; p = 0.007) occurred to be independent predictors of SBI after adjustment for confounding variables (R²  = 0.13; p = 0.001).

CONCLUSIONS

Patients with type 1 diabetes smoking cigarettes presented lower gingival sulcus bleeding and worse metabolic control of diabetes than nonsmoking patients.

Subcutaneous and Intramuscular Hemodynamics and Oxygenation After Cold-Spray Application as Monitored by Near-Infrared Spectroscopy

CONTEXT

Vapocoolant spray, commonly known as cold spray (CS), is a cryotherapy modality used in sports medicine, athletic training, and rehabilitation settings. Proposed physiologic effects of cryotherapy modalities include reductions in tissue blood flow, oxygenation, and cell metabolism in addition to attenuation of pain perception attributed to reduced superficial nerve conduction velocity.

OBJECTIVE

To examine the effects of CS on subcutaneous and intramuscular blood flow and oxygenation on the thigh muscle using near-infrared spectroscopy, an optical method to monitor changes in tissue oxygenated (O2Hb), deoxygenated (HHb), and total (tHb) hemoglobin.

DESIGN

Cross-sectional study.

SETTING

Muscle Biophysics Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Participants were 13 healthy adults (8 men, 5 women; age = 37.4 ± 6 years, body mass index = 27.4 ± 2.6, adipose tissue thickness = 7.2 ± 1.8 mm).

INTERVENTION(S)

Conventional CS was applied to the vastus medialis muscles.

MAIN OUTCOME MEASURE(S)

Changes in chromophore concentrations of O2Hb, HHb, and tHb at superficial and deep layers were monitored for 5 minutes using a 2-channel near-infrared spectroscopy.

RESULTS

Thirty seconds after CS application, we observed a decrease from baseline in O2Hb and tHb only in the superficial layer that was maintained for 3 minutes.

CONCLUSIONS

Application of CS induced a transient change in blood flow and oxygenation of the superficial tissues with no change in deeper tissues over the healthy vastus medialis muscle. The limited physiologic effect of CS on the superficial hemodynamics and oxygenation of limb muscles may limit the therapeutic benefit of this cryotherapy modality to a temporary analgesic effect, a hypothesis that warrants a clinical trial on traumatized muscles.

Assessment of the hemodynamic profile in periodontal tissues of diabetic subjects with periodontitis by optical spectroscopy

BACKGROUND AND OBJECTIVE

The influence of diabetes mellitus (DM) on the hemodynamics of periodontal tissues has not been assessed previously. The primary objective of this study was to validate optical spectroscopy as a periodontal diagnostic tool for subjects with type 2 DM and chronic periodontitis.

MATERIAL AND METHODS

Using a portable optical near-infrared spectrometer, optical spectra were obtained from healthy (n = 127), gingivitis (n = 115), and periodontitis (n = 109) sites of 65 subjects with type 2 DM and chronic periodontitis. Healthy (n = 65) sites of 15 nondiabetic subjects without periodontitis were used as controls. A modified Beer-Lambert unmixing model that incorporates a nonparametric scattering-loss function was used to determine the relative contribution of deoxygenated hemoglobin and oxygenated hemoglobin (HbO2 ) to the overall spectrum. The balance between tissue oxygen delivery and oxygen utilization in periodontal tissues was assessed.

RESULTS

In diabetic subjects, tissue oxygen saturation and HbO2 concentration were significantly decreased in the periodontitis sites (p < 0.01) compared with the healthy and gingivitis sites. Furthermore, tissue oxygenation in healthy sites of control subjects was significantly higher than that in sites of diabetic subjects (p < 0.01).

CONCLUSION

In summary, the results of this study suggest that optical spectroscopy can monitor the hemodynamic profile in diabetic subjects with chronic periodontitis. Furthermore, healthy sites of diabetic subjects presented lower tissue oxygenation than did those of nondiabetic subjects.