mTOR Signaling in the Regulation of CD4+ T Cell Subsets in Periodontal Diseases

Perception of tobacco hazards on general and periodontal health and tobacco cessation counseling among dental students

INTRODUCTION

Tobacco use is one of the leading worldwide health risk factors and a primary cause of premature death and disability. Tobacco cessation programs might work well if provided by all healthcare providers. This study aimed to evaluate dental students' knowledge, attitudes, beliefs, and practices towards tobacco hazards on general and periodontal health and tobacco cessation councling.

METHODS

A descriptive cross-sectional study was conducted among dental students who were in their clinical years (the fourth, fifth and sixth year of study), in Saudia Arabia in 2022. A self-administered questionnaire derived from the TCC questionnaire survey was carried out among 315 dental students. Knowledge was considered poor if correct answers were below the median value. Attitude was on a five-point Likert scale. Adjusted logistic regression analyses were performed.

RESULTS

The study revealed that about 52% have poor knowledge, 64% have negative attitudes, 69% have negative beliefs, and 44% poor practice. All these ratings were below median values. It also showed that younger dental students were 2 times more likely to have poor knowledge (AOR=1.97; 95% CI: 1.1-3.53) and smokers were less likely to have poor knowledge (AOR=0.34; 95% CI: 0.12-0.95). One third of students perceived patient resistance as a barrier to TCC while 50% reported lack of knowledge, 32% lack of time, and 24% lack of materials.

CONCLUSIONS

The study findings urge the inclusion of programs to encourage dental students to help patients quit tobacco use and to make educational material available to them.

New insights into nanotherapeutics for periodontitis: a triple concerto of antimicrobial activity, immunomodulation and periodontium regeneration

Periodontitis is a chronic inflammatory disease caused by the local microbiome and the host immune response, resulting in periodontal structure damage and even tooth loss. Scaling and root planning combined with antibiotics are the conventional means of nonsurgical treatment of periodontitis, but they are insufficient to fully heal periodontitis due to intractable bacterial attachment and drug resistance. Novel and effective therapeutic options in clinical drug therapy remain scarce. Nanotherapeutics achieve stable cell targeting, oral retention and smart release by great flexibility in changing the chemical composition or physical characteristics of nanoparticles. Meanwhile, the protectiveness and high surface area to volume ratio of nanoparticles enable high drug loading, ensuring a remarkable therapeutic efficacy. Currently, the combination of advanced nanoparticles and novel therapeutic strategies is the most active research area in periodontitis treatment. In this review, we first introduce the pathogenesis of periodontitis, and then summarize the state-of-the-art nanotherapeutic strategies based on the triple concerto of antibacterial activity, immunomodulation and periodontium regeneration, particularly focusing on the therapeutic mechanism and ingenious design of nanomedicines. Finally, the challenges and prospects of nano therapy for periodontitis are discussed from the perspective of current treatment problems and future development trends.

Changes of Oral Flora, Inflammatory Factors, and Immune Function Indicators in Patients with Chronic Periodontitis and Their Clinical Significance

This research focuses on investigating the changes of oral flora, inflammatory factors, and immune function indicators in patients with chronic periodontitis (CP) and their clinical significances. Clinical indices such as gingival index (GI) and sulcus bleeding index (SBI) of the study subjects were recorded. The levels of oral flora, inflammatory factors and T lymphocyte subsets in gingival crevicular fluid (GCF) of the study subjects were measured. To analyze the correlation between GI and gingival SBI and oral flora, inflammatory factors, and immune function indicators, Pearson correlation analysis was performed. Porphyromonas gingivalis, Streptococcus digestiveis, Prevotella intermedia, Veronococcus, tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-8, CD3+, CD4+, and CD4+/CD8+ had a positive correlation with GI and SBI, while IL-10 and CD8+ were negatively correlated with GI and SBI. Oral flora, inflammatory factors and immune function indicators levels are largely elevated in patients with CP and they are correlated with CP clinical indicators.

Comparative Evaluation of Gingival Crevicular Fluid Interleukin-17, 18 and 21 in Different Stages of Periodontal Health and Disease

Background and Objectives: The elicitation of a host’s immune−inflammatory responses to overcome oral bacterial biofilm challenges is mediated by numerous cytokines. We explored the role of three such cytokines, viz. interleukin (IL)-17, 18 and 21, by measuring their levels in the gingival crevicular fluid (GCF) of Indian individuals with healthy gingiva, chronic gingivitis, or chronic periodontitis. Materials and Method: Ninety systemically healthy individuals were enrolled in the study on the basis of predefined criteria and were categorized into three groups of 30 participants each. Groups A, B and C were composed of a control group with healthy gingiva, subjects with chronic gingivitis and subjects with chronic periodontitis, respectively. The periodontal disease status was assessed on the basis of a subject’s gingival index, probing pocket depth, clinical attachment loss and radiographic evidence of bone loss. After the complete history-taking and identification of gingival sulcus/pocket depth areas for GCF collection, a sample was collected from each subject in all groups for an estimation of the cytokine levels using ELISA. Statistical analysis was performed using SPSS v 21.0. Intergroup comparisons were conducted using a post hoc Tukey’s test. A value of p < 0.05 was considered to be statistically significant. Results: The mean IL-17, 18 and 21 concentrations in pg/mL was the greatest for Group C (99.67 ± 18.85, 144.61 ± 20.83 and 69.67 ± 12.46, respectively), followed by Group B (19.27 ± 2.78, 22.27 ± 2.43 and 22.74 ± 1.43, respectively) and finally by Group A (healthy control; 11.56 ± 0.99, 17.94 ± 1.24 and 12.83 ± 1.21 respectively). A statistically significant difference in the mean concentrations of two interleukins (IL-17 and IL-18) was observed between Groups A and C and also between Groups B and C. A statistically significant difference in the mean concentrations of IL-21 was observed between Groups B and C. Conclusions: Within the limitations of the present study, the findings revealed that the GCF levels of IL-17, IL-18 and IL-21 rose and correlated well with the severity of the disease. Thus, these cytokines present in GCF have the potential to be considered as biomarkers for periodontal tissue destruction. IL-21 in particular appears to be a promising biomarker for differentiating between gingivitis and periodontitis.

Clinical and Molecular Characteristics of 60 Patients With Human Immunodeficiency Virus-Negative Castleman Disease

Castleman disease (CD) is a rare lymphoproliferative disorder. The mechanistic target of rapamycin (mTOR) pathway is a key regulator of various cellular functions, which may be related with the potential mechanisms of CD occurrence. We retrospectively collected the clinical information of 60 CD patients diagnosed in the First Affiliated Hospital of Zhengzhou University. And FFPE biopsy specimens were collected from 31 patients (12 unicentric CD patients and 19 multicentric CD patients) to detect the mTOR pathway protein expression. We are the first to demonstrate that thrombocytopenia and hypoalbuminemia are independent poor prognostic factors for CD. Moreover, mTOR activation was higher in CD compared to reactive lymphoid hyperplasia (used as a control group). This study offers some elucidation for the management and treatment of CD patients.

Heterogeneity of Blood Vessels and Assessment of Microvessel Density-MVD in Gingivitis

Gingivitis is a very common oral disease highly prevalent in adults that, if left untreated, can progress to periodontitis. It involves a complex and slow interaction between the host response and the oral microbiome represented by the dental plaque. The inflammation of the gingiva is associated with the activation of pathological angiogenesis and the existence of a high number of newly formed blood vessels quantified as microvessel density (MVD). The present study includes a number of 51 gingival biopsies from patients with different gingival indexes (GI): GI = 0, n = 12; GI = 1, n = 15; GI = 2, n = 16; and GI = 3, n = 8, processed and stained with the routine hematoxylin–eosin method. The inflammatory infiltrate was scored, the blood vessels were detected with anti-CD34 antibody, and MVD was determined. Inflammatory changes were observed in 39 of the 51 cases included in our study. CD34 + vessels with normal morphological appearance were observed in all 12 cases of health gingiva. In cases of inflammatory lesions, the morphology of the blood vessels showed changes with the evolution of gingival lesions. In severe inflammation, a particular aspect was observed in the vessels, such as the presence of the phenomenon of intussusception. MVD increases with the severity of gingival lesions, with the highest density being observed in severe inflammation.