Physiopathology of nitric oxide in the oral environment and its biotechnological potential for new oral treatments: a literature review

Evaluation of salivary nitric oxide levels and anxiety in multiple sclerosis patients, with and without Xerostomia: correlation with clinical variables

BACKGROUND

Xerostomia is a prevalent but often overlooked condition in multiple sclerosis (MS) patients, significantly impacting their quality of life and oral health. This cross-sectional observational study investigates the role of nitric oxide (NO) in the pathophysiology of multiple sclerosis (MS) and explores its association with xerostomia in MS patients. The primary objective was to compare salivary NO concentrations and stress levels between MS patients with and without xerostomia.

METHODS

MS patients diagnosed by neurologists and MRI were categorized into two groups: those with xerostomia and those without. Unstimulated whole saliva samples were collected using the spitting method, and salivary NO levels were quantified using an enzyme-linked immunosorbent assay (ELISA) kit based on the Griess reaction. Stress levels were assessed using the Beck Anxiety Inventory (BAI) questionnaire. The presence of xerostomia was evaluated through the Xerostomia Inventory (XI) and clinical examinations.

RESULTS

Salivary NO levels were significantly higher in MS patients without xerostomia (227.47 ng/mL) compared to those with xerostomia (102.37 ng/mL, p < 0.001). Stress levels were also notably higher in MS patients with xerostomia (17.23) versus those without (11.77, p = 0.03). A moderate negative correlation was observed between salivary NO levels and xerostomia (r = 0.44, p < 0.001), indicating that lower NO levels were associated with a higher likelihood of xerostomia. The correlation between stress levels and xerostomia was weaker but still significant (r = 0.28, p = 0.03). Multivariate binary logistic regression analysis identified salivary NO, stress levels, and age as significant predictors of xerostomia in MS patients. The logistic regression model achieved an 80% accuracy in predicting xerostomia based on salivary NO levels and stress.

CONCLUSION

This study highlights a significant negative correlation between salivary NO levels and xerostomia, suggesting that decreased salivary NO concentrations are associated with an increased risk of xerostomia in MS patients. Additionally, stress levels were positively correlated with xerostomia, indicating a potential link between higher stress and the likelihood of xerostomia in MS patients.

Evaluation of Anti-Inflammatory and Antibacterial Properties of Photo-Thermal Hydrogel as Dual Functional Platform for Management of Periodontitis

Background

Periodontitis, one of the most common oral diseases caused by bacterial infection which affects gums, periodontal ligament and alveolar bone, is a leading cause of tooth loss in adults. Current clinical treatments, such as scaling or antibiotics, often result in incomplete biofilm removal or can contribute to drug resistance.

Methods

To address these limitations, a nanozyme comprising platinum, copper, and selenium was developed, which was then incorporated into a thermoresponsive hydrogel.

Results

When applied to periodontal pockets and exposed to 808 nm laser irradiation, the hydrogel became soft, dissolving to release the nanozyme. This nanozyme demonstrated superoxide dismutase (SOD)-like and catalase (CAT)-like activity, reducing excess reactive oxygen species (ROS) while displaying strong antibacterial and anti-inflammatory effects.

Conclusion

This photothermal nanozyme hydrogel showed excellent biocompatibility and has the potential to overcome the challenges of current periodontitis treatments.

Maintaining Hygiene in Orthodontic Miniscrews: Patient Management and Protocols-A Literature Review

BACKGROUND

Oral hygiene is crucial for the success of orthodontic therapy involving temporary anchoring devices like miniscrews. Plaque buildup, exacerbated by orthodontic appliances, causes inflammation that can undermine treatment outcomes. Individualized prevention plans based on patient risk factors are essential. This review emphasizes the importance of oral hygiene in orthodontic therapy with miniscrews, identifies optimal devices for ensuring long-term stability, and explores protocols for high-risk patients.

MATERIALS AND METHODS

A comprehensive search was conducted on two primary databases, PubMed and Google Scholar, for relevant articles on oral hygiene and inflammation. Fourteen articles meeting the inclusion criteria were selected, covering topics such as "orthodontic miniscrew", "miniscrew and laser", "miniscrew and mouthwash", "electric toothbrush", and "GBT".

RESULTS

Inflammation can compromise miniscrew stability by damaging surrounding bone. Miniscrews of 10 mm length have lower failure rates due to better bone contact and stability. Chlorhexidine reduces inflammation risk and inhibits epithelialization around the implant head. Laser therapy enhances miniscrew stability and reduces inflammation. Chitosan effectively suppresses inflammatory mediators and prevents microorganism adhesion. Both sonic and roto-oscillating electric toothbrushes remove plaque effectively, with roto-oscillating brushes showing superior results. The Guided Biofilm Therapy (GBT) protocol offers professional hygiene benefits similar to traditional methods, with improved patient engagement and motivation.

CONCLUSIONS

Home oral hygiene maintenance is paramount for preventing inflammatory complications. Professional interventions such as diode laser usage, particularly in adult patients with a history of periodontitis or underlying systemic conditions, can mitigate orthodontic therapy failure risks. The GBT protocol fosters a more comfortable and participatory professional hygiene experience for patients, promoting better oral health awareness and compliance.

Whole-Genome Deep Sequencing of the Healthy Adult Nasal Microbiome

This study aimed to determine shifts in microbial populations regarding richness and diversity from the daily use of a popular over-the-counter nasal spray. In addition, the finding of nasal commensal bacterial species that overlap with the oral microbiome may prove to be potential probiotics for the "gateway microbiomes". Nasal swab samples were obtained before and after using the most popular over-the-counter (OTC) nasal spray in 10 participants aged 18-48. All participants were healthy volunteers with no significant medical histories. The participants were randomly assigned a number by randomizing software and consisted of five men and five women. The sampling consisted of placing a nasal swab atraumatically into the nasal cavity. The samples were preserved and sent to Northwestern University Sequencing Center for whole-genome deep sequencing. After 21 days of OTC nasal spray use twice daily, the participants returned for further nasal microbiome sampling. The microbial analysis included all bacteria, archaea, viruses, molds, and yeasts via deep sequencing for species analysis. The Northwestern University Sequencing Center utilized artificial intelligence analysis to determine shifts in species and strains following nasal spray use that resulted in changes in diversity and richness.

Microbial metabolites in the pathogenesis of periodontal diseases: a narrative review

The purpose of this narrative review is to highlight the importance of microbial metabolites in the pathogenesis of periodontal diseases. These diseases, involving gingivitis and periodontitis are inflammatory conditions initiated and maintained by the polymicrobial dental plaque/biofilm. Gingivitis is a reversible inflammatory condition while periodontitis involves also irreversible destruction of the periodontal tissues including the alveolar bone. The inflammatory response of the host is a natural reaction to the formation of plaque and the continuous release of metabolic waste products. The microorganisms grow in a nutritious and shielded niche in the periodontal pocket, protected from natural cleaning forces such as saliva. It is a paradox that the consequences of the enhanced inflammatory reaction also enable more slow-growing, fastidious, anaerobic bacteria, with often complex metabolic pathways, to colonize and thrive. Based on complex food chains, nutrient networks and bacterial interactions, a diverse microbial community is formed and established in the gingival pocket. This microbiota is dominated by anaerobic, often motile, Gram-negatives with proteolytic metabolism. Although this alternation in bacterial composition often is considered pathologic, it is a natural development that is promoted by ecological factors and not necessarily a true "dysbiosis". Normal commensals are adapting to the gingival crevice when tooth cleaning procedures are absent. The proteolytic metabolism is highly complex and involves a number of metabolic pathways with production of a cascade of metabolites in an unspecific manner. The metabolites involve short chain fatty acids (SCFAs; formic, acetic, propionic, butyric, and valeric acid), amines (indole, scatole, cadaverine, putrescine, spermine, spermidine) and gases (NH₃, CO, NO, H₂S, H₂). A homeostatic condition is often present between the colonizers and the host response, where continuous metabolic fluctuations are balanced by the inflammatory response. While it is well established that the effect of the dental biofilm on the host response and tissue repair is mediated by microbial metabolites, the mechanisms behind the tissue destruction (loss of clinical attachment and bone) are still poorly understood. Studies addressing the functions of the microbiota, the metabolites, and how they interplay with host tissues and cells, are therefore warranted.

Role of nitric oxide in orthodontic tooth movement (Review)

Nitric oxide (NO) is an ubiquitous signaling molecule that mediates numerous cellular processes associated with cardiovascular, nervous and immune systems. NO also plays an essential role in bone homeostasis regulation. The present review article summarized the effects of NO on bone metabolism during orthodontic tooth movement in order to provide insight into the regulatory role of NO in orthodontic tooth movement. Orthodontic tooth movement is a process in which the periodontal tissue and alveolar bone are reconstructed due to the effect of orthodontic forces. Accumulating evidence has indicated that NO and its downstream signaling molecule, cyclic guanosine monophosphate (cGMP), mediate the mechanical signals during orthodontic-related bone remodeling, and exert complex effects on osteogenesis and osteoclastogenesis. NO has a regulatory effect on the cellular activities and functional states of osteoclasts, osteocytes and periodontal ligament fibroblasts involved in orthodontic tooth movement. Variations of NO synthase (NOS) expression levels and NO production in periodontal tissues or gingival crevicular fluid (GCF) have been found on the tension and compression sides during tooth movement in both orthodontic animal models and patients. Furthermore, NO precursor and NOS inhibitor administration increased and reduced the tooth movement in animal models, respectively. Further research is required in order to further elucidate the underlying mechanisms and the clinical application prospect of NO in orthodontic tooth movement.