Nanoplasmonic Strip Test for Salivary Glucose Monitoring

Nowadays, there is an increasing interest in Point-of-care (POC) devices for the noninvasive glucose assessment. Despite the recent progress in glucose self-monitoring, commercially available devices still use invasive samples such as blood or interstitial fluids, and they are not equipment-free and affordable for the whole population. Here, we report a fully integrated strip test for the semi-quantitative detection of glucose in whole saliva. The colorimetric mechanism consists of an enzyme-mediated reshaping of multibranched gold nanoparticles (MGNPs) into nanospheres with an associated plasmonic shift and consequent blue-to-red color change, clearly detectable in less than 10 min.

Association of salivary pH in patients with dental caries and periodontal disease

Background: The aims of the study was to find out the prevalence of dental caries in healthy and periodontal disease and its association with salivary pH.Methods: A total of 80 healthy subjects reporting to the department of periodontology were selected. They were divided into four groups (clinically healthy gingival, chronic generalized gingivitis, chronic generalized periodontitis, and aggressive periodontitis) with 20 subjects in each. Periodontal parameters; decayed, missing, and filled teeth (DMFT) index and salivary pH were recorded. Unstimulated whole saliva was collected according to Navazesh method. The pH of saliva was immediately measrued using a single electrode digital pH meter.Results: Based on statistical test it was seen that caries prevalence and DMFT was found out to be least in aggressive periodontitis group, along with least mean pH value, as compared to the other 3 groups, p<0.05.Conclusions: The low prevalence of caries in aggressive periodontitis can be attributed to the low pH of saliva. Salivary pH plays a vital role in the formation of microbial film, which in turn has a significant role in the pathogenesis of both dental caries and periodontitis.

Impact of the Glycemic Level on the Salivary Proteome of Middle-Aged and Elderly People With Type 2 Diabetes Mellitus: An Observational Study

Type 2 diabetes mellitus (T2DM) is an increasing global public health concern, but its impact on the salivary proteome is still unclear. To evaluate the effect of glycemic levels in middle-aged and elderly individuals with T2DM on salivary proteomics, we compared the differences by liquid chromatography tandem mass spectrometry (LC–MS/MS). Unstimulated whole saliva samples from 8 T2DM patients with good glycemic control (G group, HbA1c &lt;6.5%) and 16 patients with poor control (P group, HbA1c ≥6.5%) were analyzed by LC–MS/MS in the data-independent acquisition mode (Clinical register number: ChiCTR1900023582.). After functional annotation, cluster analysis and receiver operating characteristic (ROC) curve analysis were carried out to screen and evaluate candidate proteins. A total of 5,721 proteins were quantified, while 40 proteins differed significantly. In the P group, proteins involved in oxidative stress-related processes were upregulated, whereas proteins related to salivary secretion were downregulated. The combination of thioredoxin domain-containing protein 17, zymogen granule protein 16B, and FAM3 metabolism regulating signaling molecule D yielded an area under the curve of 0.917 which showed a robust ability to distinguish the P and G groups. In conclusion, poorly controlled hyperglycemia may affect salivary proteins through various pathways, including oxidative stress and glandular secretion. Furthermore, the differentially expressed proteins, especially the three proteins with the best differentiation, might serve as an anchor point for the further study of hyperglycemia and oral diseases.

Serum and Saliva 25(OH)D Levels in Relation to Dental Caries in Young Children

Objective: Several studies have reported that low levels of vitamin D (25(OH)D) are associated with an increased risk of dental caries and that optimal levels may offer protection This study aimed to assess the relationship between serum and saliva 25(OH)D levels and caries among young children. Study design: A total of 120 healthy children were recruited; 93 with caries and 27 caries-free. Dental caries status was evaluated using decayed, missing and filled in primary teeth (dmft) index. Blood and unstimulated whole saliva samples were collected. Laboratory analysis was performed using Enzyme-Linked Immunosorbent Assay Kit. Data were analyzed with descriptive statistics, bivariate and Spearman’s rank correlation analysis. Results: There were no significant associations between serum and saliva 25(OH)D levels and caries status (P &gt; 0.05). Levels of 25(OH)D in serum were significantly higher than levels found in saliva (P &lt; 0.05), and a correlation between serum and saliva 25(OH)D levels was observed (P &lt; 0.05). Conclusions: The association between serum and saliva 25(OH)D and dental caries in young children was inconclusive. However, a positive and significant correlation was observed between serum and saliva 25(OH)D levels. Further studies are warranted to investigate the definite relation between 25(OH)D levels and dental caries and using saliva 25(OH)D as a non-invasive alternative method over blood samples.

Salivary cystatin S levels in children with early childhood caries in comparison with caries-free children; statistical analysis and machine learning

Background Early childhood caries is the most common infectious disease in childhood, with a high prevalence in developing countries. The assessment of the variables that influence early childhood caries as well as its pathophysiology leads to improved control of this disease. Cystatin S, as one of the salivary proteins, has an essential role in pellicle formation, tooth re-mineralization, and protection. The present study aims to assess salivary cystatin S levels and demographic data in early childhood caries in comparison with caries-free ones using statistical analysis and machine learning methods. Methods A cross-sectional, case–control study was undertaken on 20 cases of early childhood caries and 20 caries-free children as a control. Unstimulated whole saliva samples were collected by suction. Cystatin S concentrations in samples were determined using human cystatin S ELISA kit. The checklist was collected from participants about demographic characteristics, oral health status, and dietary habits by interviewing parents. Regression and receiver operating characteristic (ROC) curve analysis were done to evaluate the potential role of cystatin S salivary level and demographic using statistical analysis and machine learning. Results The mean value of salivary cystatin S concentration in the early childhood caries group was 191.55 ± 81.90 (ng/ml) and in the caries-free group was 370.06 ± 128.87 (ng/ml). T-test analysis showed a statistically significant difference between early childhood caries and caries-free groups in salivary cystatin S levels (p = 0.032). Investigation of the area under the curve (AUC) and accuracy of the ROC curve revealed that the logistic regression model based on salivary cystatin S levels and birth weight had the most and acceptable potential for discriminating of early childhood caries from caries-free controls. Furthermore, using salivary cystatin S levels enhanced the capability of machine learning methods to differentiate early childhood caries from caries-free controls. Conclusion Salivary cystatin S levels in caries-free children were higher than the children with early childhood caries. Results of the present study suggest that considering clinical examination, demographic and socioeconomic factors, along with the salivary cystatin S levels, could be usefull for early diagnosis ofearly childhood caries in high-risk children; furthermore, cystatin S is a protective factor against dental caries.

SARS-CoV-2 Delta variant saliva viral load is 15-fold higher than wild-type strains

The emergence of SARS-CoV-2 Delta variants has escalated COVID-19 cases globally due to their high transmissibility. Since saliva is crucial for SARS-CoV-2 transmission, we hypothesized that a higher viral load of Delta variants in saliva than their parental wild-type strains contributed to the high transmissibility in the first place. However, studies have not reported this particular comparison done with viral copy numbers. Twenty-two genetically confirmed -positive saliva samples for wild-type strain and 32 Delta variants were statistically compared for viral copy number per milliliter determined by real-time qPCR combined with synthesized viral RNA and Poisson's null distribution equation between the groups of wild and variant strains and between whole saliva and centrifugal supernatant in each group. We found that the copy number of the Delta variants was 15.1 times higher than wild-type strains of the whole saliva. In addition, the viral load of both strains in the whole saliva was higher than the pertinent supernatant, indicating that most viruses in the whole saliva are associated with host cells. Meanwhile, more than a million virions per milliliter of the viral load of the variants in the supernatants were 4.0 times higher but not significant than wild-type strains. Humanity must share our findings; the simple but concrete note that Delta variant viral load is abundant in the saliva is critical for preventing the spread of infection.

Aggregatibacter actinomycetemcomitans and Aggregatibacter aphrophilus in a Kenyan Maasai Adolescent Population and Inhibition of Leukotoxic Activity by Herbal Plants Used as Part of Oral Hygiene Procedures

Background: A virulent genotype (JP2) of the periodonto-pathogen, Aggregatibacter actinomycetemcomitans (Aa), is widespread in North and West Africa, while its presence in East Africa has not been thoroughly investigated. This JP2 genotype is associated with periodontitis in adolescents and has a high leukotoxicity. The aim of the study was to examine the prevalence of Aa and its JP2 genotype, the prevalence of the oral, commensal Aggregatibacter aphrophilus in a Maasai adolescent population, and the effect of herbal plants for inhibition of leukotoxicity. Methods: A total of 284 adolescents from Maasai Mara, Kenya, underwent an oral examination and microbial sampling. The presence of Aa and A. aphrophilus was analyzed by quantitative PCR and cultivation (the 58 samples collected at the last day of field study). The collected Aa strains were characterized and leukotoxin promoter typed. Additionally, herbal plants commonly used for oral hygiene were assessed for the inhibition of leukotoxicity. Results and Conclusions: The prevalence of Aa in stimulated whole saliva was high (71.8%), with the JP2 genotype detected in one individual, and A. aphrophilus in 99% of the sampled individuals. The commonly used herbal plant, Warburgia ugandensis, inactivated Aa leukotoxicity. The Aa virulence might be reduced through use of W. ugandensis and the high levels of A. aphrophilus.

The Association of Early Childhood Caries with Salivary Antimicrobial Peptide LL37 and Mutans Streptococci

Purpose: This study aims to determine the relation of salivary LL37 level and mutans streptococci levels in early childhood caries (ECC). Study design: A case-control study was performed in children ≤71 months old. Unstimulated whole saliva was collected and the level of salivary LL37 was measured using an enzyme-linked immunosorbent assay kit. The mutans streptococci oral bacteria were isolated from saliva and identified using a modified SB-20 culture medium (SB-20M). Data were analyzed using descriptive statistics, bivariate, and Spearman’s rank correlation analysis. Results: The was a variability of salivary LL37 level among the children and the level was significantly associated with age and races. The median (IQR) value of salivary LL37 in caries-free (CF) children was significantly higher 393.50 (580.55) ng/mL compared to 172.50 (234.65) ng/mL in the ECC group. The ECC children exhibited a significantly higher count of S. mutans and S. sobrinus compared to the CF children. An inverse weak correlation between salivary LL37 and dmft was also observed. Conclusions: The low salivary LL37 level and higher S. mutans and S. sobrinus count in ECC supported the protective role of salivary LL37 against dental caries. Further studies are required to explore the definite relation between salivary LL37 levels and dental caries.

A Comparative Quantitative Assessment of Salivary Iga and Alpha Amylase in Caries Free and Caries Active Children

Objectives: The aim of the study was to assess the salivary IgA (immunoglobulin A) and alpha amylase levels in the unstimulated whole saliva samples of caries-free and caries-active children and correlate it with the caries status and age. Study design: The salivary IgA and amylase was investigated in 100 children in the range of 8–12 years divided in two groups, control group (DMFT and/or deft = 0) and study group (DMFT/deft score ≥5). The salivary IgA was measured using kit based on two-site sandwich enzyme immunoassay principle and amylase was estimated using the vitro amyl slides. Results :The mean salivary IgA and amylase levels in the saliva of the children in the control group was found to be significantly increased (p=.001 and p=.014 respectively) whereas the relationship between salivary IgA and amylase levels in the saliva of the children was found to be insignificant with the age (p=.392 and p=.306 respectively). Conclusions: The results indicated that salivary IgA and amylase levels in saliva increased significantly in caries free children and the level of salivary IgA and alpha amylase has no significant relation with the age of the children.

Interaction between properties of commercial Australian honey and saliva: in vitro exploratory study of a potential mechanism in the treatment of oral mucositis

Objectives Oral mucositis is a debilitating oncology treatment side effect, with honey identified as a viable management option due to established wound-healing abilities. However, effects of saliva on properties attributed to honey’s wound-healing abilities is unknown. Therefore, this study aimed to identify interactions between saliva, and antioxidant characteristics and pH of honey. Methods Saliva was collected from 15 healthy participants (Females n=9; mean age=34.1 ± 11.2 years). Centrifuged salivary supernatant, whole saliva, and water were independently used to dilute commercial Australian honeys (n=42). Antioxidant characteristics (DPPH and FRAP) and pH of diluted honeys were analysed, and differences between dilution conditions were determined. Results Honey and saliva dilutions increased antioxidant characteristics compared to water, and addition of honey to saliva reduced pH compared with saliva alone. There were significant differences between dilutions for FRAP and pH, and water and salivary conditions for DPPH (p<0.001). No difference was observed between salivary conditions for DPPH (p=0.931), suggesting smaller cells remaining in the supernatant possess antioxidant abilities. However, differences observed for FRAP suggest precipitable molecules, including epithelial and food debris, could provide additional antioxidant power. Conclusions The addition of saliva to honey may support properties attributed to honey’s wound-healing abilities and should be considered in the context of oral mucositis management.