The impact of saliva collection methods on measured salivary biomarker levels

H Al Habobe, EB Haverkort, K Nazmi, AP Van Splunter, RHH Pieters, FJ Bikker (https://doi.org/10.1016/j.cca.2023.117628)

Saliva diagnostics have become increasingly popular due to their non-invasive nature and patient-friendly collection process. Various collection methods are available, yet these are not always well standardized for either quantitative or qualitative analysis. In line, the objective of this study was to evaluate if measured levels of various biomarkers in the saliva of healthy individuals were affected by three distinct saliva collection methods: 1) unstimulated saliva, 2) chew stimulated saliva, and 3) oral rinse. Saliva samples from 30 healthy individuals were obtained by the three collection methods. Then, the levels of various salivary biomarkers such as proteins and ions were determined. It was found that levels of various biomarkers obtained from unstimulated saliva were comparable to those in chew stimulated saliva. The levels of potassium, sodium, and amylase activity differed significantly among the three collection methods. Levels of all biomarkers measured using the oral rinse method significantly differed from those obtained from unstimulated and chew-stimulated saliva. In conclusion, both unstimulated and chew-stimulated saliva provided comparable levels for a diverse group of biomarkers. However, the results obtained from the oral rinse method significantly differed from those of unstimulated and chew-stimulated saliva, due to the diluted nature of the saliva extract

The diagnostic power of salivary electrolytes for Sjögren’s disease: a systematic literature review and meta-analysis

Joanita S van Santen, Zainab Assy, Floris J Bikker, Marja L Laine, Arjan Vissink, Frans G M Kroese, Sarah Pringle (https://doi.org/10.55563/clinexprheumatol/648k4u)

Objectives: To perform a systematic review and meta-analysis to determine the power of salivary electrolytes for the diagnosis of Sjögren’s disease (SjD). Methods: A literature search was conducted (last search March 2023) using PubMed and Web of Science and completed with a manual search. Articles were screened for reports of human salivary ion concentrations, comparing SjD patients with healthy controls and/or sicca patients. Articles not using the SjD classification criteria or performing the classification as part of the experimental design were excluded. Forest plots were used to present the meta-analyses results for each ion, distinguishing between salivary type (unstimulated and stimulated whole saliva, submandibular/sublingual and parotid saliva). Results: A total of 21 out of 722 articles were eligible for inclusion. For SjD patients a significant increase in salivary ion concentration was observed for sodium, chloride and calcium when comparing to healthy controls. Significant differences between SjD and sicca patients were noted for sodium, chloride, phosphate, calcium, phosphate, nitrite and nitrate. Stimulated whole saliva showed larger variability in results between studies in comparison to other types of saliva (unstimulated whole saliva, submandibular/sublingual saliva and parotid saliva). Conclusions: Despite differences in saliva type, salivary ion levels could be utilised for the screening for SjD. Making use of chloride in combination with sodium would be most promising for distinguishing SjD patients from healthy controls and adding phosphate to potentially make a distinguishment with sicca patients. Unstimulated whole saliva should be the first choice when testing salivary ion concentrations.

A technical note on the Kamranmeter; a manually operated device for measuring salivary spinnbarkeit

Kamran Nazmi, Mouri Rumaila Jannath Faruque, Antonius Jacobus Marie Ligtenberg, Henderikus Pots, Wendy Esmeralda Kaman, Marja Leena Laine, Zainab Assy, Floris Jacob Bikker (https://doi.org/10.1007/s00784-024-06047-w)

Objective: The objective was to develop a manually operatable, non-electric device to measure salivary spinnbarkeit for research, clinical and educational purposes. Materials and methods: A newly developed device, named the Kamranmeter, was built and evaluated in a pilot study, comparing the spinnbarkeit of unstimulated and chew-stimulated saliva samples from healthy volunteers. The Neva Meter, which operates on electrical resistance, was used as a reference standard. Results: The study found no statistically significant differences between the two devices when measuring the spinnbarkeit of both unstimulated and stimulated saliva samples from healthy volunteers. Conclusions: We developed a hand-operated device to analyse salivary spinnbarkeit. The Kamranmeter performs comparably to the Neva Meter in measuring spinnbarkeit in saliva obtained from healthy volunteers. Clinical relevance: The Kamranmeter has potential applications in diagnostic tests involving saliva, such as assessing spinnbarkeit to evaluate conditions like caries and dry mouth. Moreover, it holds promise for broader medical uses, including fertility assessments, where spinnbarkeit is a key indicator of cervical mucus quality. Its ease of handling is expected to make it well-suited for research, clinical, and educational applications.

The Prevalence of Metabolic Syndrome and Undiagnosed Diabetes in Periodontitis Patients and Non-Periodontitis Controls in a Dental School

Madeline X F Kosho, Alexander R E Verhelst, Wijnand J Teeuw, Sebastiaan van Bruchem, Kamran Nazmi, Victor E A Gerdes, Bruno G Loos (https://doi.org/10.3390/jcm13247512)

Background/Objectives: Metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM) are major global health concerns, and they often go undetected. Periodontitis shares risk factors and is associated with both conditions. Assessing MetS risk factors among dental patients, especially those with periodontitis, may contribute to early detection and prompt treatment. However, current information about MetS prevalence rates in dental settings is limited. Therefore, our aim was to investigate the prevalence of MetS among patients with generalized periodontitis stage III/IV (GenPD), localized periodontitis stage III/IV (LocPD), and non-periodontitis controls. We also investigated the prevalence of undiagnosed T2DM in the same population. Moreover, we performed a pilot study to evaluate the possibility of measuring fructosamine levels in oral rinse samples, as an alternative to HbA1c, to screen for hyperglycemia. Methods: Periodontitis patients and non-periodontitis controls were recruited from a dental school, all aged ≥ 40 years. MetS prevalence was determined according to four different MetS definitions. T2DM prevalence was based on elevated HbA1c levels (HbA1c ≥ 7.0%). Biochemical analysis from blood was carried out by finger stick sampling. A subset of participants was asked to provide an oral rinse sample for the measurement of fructosamine, which was correlated to HbA1c from blood. Results: A total of 105 patients with periodontitis (GenPD stage III/IV: n = 44, LocPD stage III/IV: n = 61) and 88 non-periodontitis controls, with a mean age of 54.4 years, were included. The prevalence of MetS, according to four different MetS definitions, was 68.2-81.8% in GenPD patients, 42.6-62.3% in LocPD patients, and 52.3-69.3% in controls. The prevalence of T2DM, as evidenced by elevated HbA1c, was 20.5% in GenPD patients, 18.3% in LocPD patients, and 10.2% in controls (p = 0.094). A substantial number of subjects were not aware that they were being suspected to have T2DM, i.e., 13.6% in GenPD patients, 8.2% in LocPD patients, and 8.0% in controls (p = 0.335). In a subset of participants (n = 48), we found no significant correlation between HbA1c and oral fructosamine (r= 0.24, p = 0.103). Conclusions: The overall results showed a relatively high prevalence of patients with MetS and/or elevated HbA1c among periodontitis patients and controls in the dental school. Of those with suspected T2DM, a substantial number were not aware of having T2DM. Oral health care professionals could therefore contribute to early detection for T2DM and/or create awareness in patients at risk for a disease related to MetS. To date, initial results on the use of oral fructosamine as an alternative for HbA1c cast doubt, and further research is needed.

Metabolomic Profiles of Oral Rinse Samples to Distinguish Severe Periodontitis Patients From Non-Periodontitis Controls

Madeline X F Kosho, Alessio Ciurli, Martin Giera, Jacques Neefjes, Bruno G Loos (https://doi.org/10.1111/jre.13379)

Aims: To explore the potential of metabolomic profiles of oral rinse samples to distinguish between patients with severe periodontitis (stage III/IV) and non-periodontitis controls. This is coupled to an analysis of differences in metabolomic profiles between individuals without periodontitis, patients with localized periodontitis, and patients with generalized periodontitis. Methods: Periodontitis patients and controls were recruited, all aged ≥ 40 years. Study participants were asked to rinse vigorously for 30 s with 10 mL phosphate buffered saline. Metabolites were identified using a semi-targeted liquid chromatography tandem mass spectrometry (LC-MS/MS) platform. Results: In total, 38 periodontitis patients (18 localized, 20 generalized stage III/IV periodontitis patients) and 16 controls were included. Metabolomic profiles of oral rinse samples were able to distinguish patients with severe periodontitis (stage III/IV) from non-periodontitis controls. Among various variables for the severity of periodontitis, we found that the number of sites with deep pockets (PPD) ≥ 6 mm explained best the differences in metabolomic profiles between controls and patients with severe periodontitis. Subjects with a high number of sites with PPD ≥ 6 mm were characterized by a higher level of phosphorylated nucleotides, amino acids, peptides, and dicarboxylic acids. Metabolomic profiles were also significantly different between controls vs. generalized periodontitis and between localized periodontitis vs. generalized periodontitis (p < 0.05). Conclusion: Our study demonstrates that simply collected oral rinse samples are suitable for LC-MS/MS based metabolomic analysis. We show that a metabolomic profile with a substantial number of metabolites can distinguish severe periodontitis patients from non-periodontitis controls. These observations can be a basis for further studies into screening to identify subjects with the risk of having severe periodontitis.

The Prevalence of Comorbidities in Individuals with Periodontitis in a Private Periodontal Referral Practice

Nicky G F M Beukers, Bruno G Loos, Geert J M G van der Heijden, Elena Stamatelou, Athanasios Angelakis, Naichuan Su (https://doi.org/10.3390/jcm13237410)

Objectives: Periodontitis (PD) patients frequently suffer from comorbidities, necessitating increased attention to disease management and monitoring. The aim of this study is to describe the prevalence and patterns of comorbidities among patients with PD in a private periodontal referral practice. Methods: This study involved 3171 adults with PD. Data on demographics, lifestyle, number of teeth, pockets of size ≥ 6 mm, bleeding on probing, periodontal inflammatory surface area, and comorbidities were extracted from electronic patient records. Descriptive and statistical analyses, including t-tests, chi-square tests, cluster analysis, binomial logistic regression analysis, and hypergraph network analysis, were performed. Results: Among this PD population, 47% had a comorbidity, and 20% had multimorbidity (≥2 diseases). Based on the disease patterns, two distinct clusters emerged: Cluster 1 was dominated by respiratory tract conditions (asthma, lung disease, and allergic rhinitis), allergies, and hypothyroidism, while Cluster 2 primarily included cardiometabolic diseases (angina pectoris, hypertension, diabetes mellitus (DM), and hyperthyroidism). The hypergraph network analysis for those with multimorbidity identified two main groups: (i) pulmonary conditions (lung disease, asthma, allergic rhinitis, and allergies) and (ii) cardiometabolic disorders (hypertension, myocardial infarction, cerebrovascular disease, and DM). Hypertension, allergies, and allergic rhinitis showed high centrality, serving as central nodes frequently co-occurring with other diseases. Conclusions: Nearly half of the PD patients in a private periodontal referral practice were found to have comorbidities, primarily clustering into cardiometabolic and respiratory tract diseases. These findings, based on real-world data, should encourage dental professionals to integrate systemic conditions into their care strategies. They could also guide policymakers and practitioners in developing evidence-based approaches to mitigate the reciprocal negative effects of PD and comorbidities.

Exploring the relationship of salivary pH and flow rate with tooth wear severity: A cross-sectional study

Víctor I Madariaga, Tatiana Pereira-Cenci, Lucky L A van Gennip, Stephanie J M van Leeuwen, X Frank Walboomers, Bas A C Loomans (https://doi.org/10.1016/j.jdent.2024.105499)

Background: Tooth wear is the loss of dental hard tissue due to chemical and mechanical processes, and its prevalence ranges from 13 to 80 % in the general population. Management depends on understanding potential risk factors; however, the role of saliva as one of them is not completely understood. The aim of this study was to explore the relationship between salivary pH and flow, and tooth wear in patients referred to a specialized dental clinic for tooth wear management. Methodology: Data used in this study included stimulated (SWS) and unstimulated whole salivary (UWS) pH and flow rate. Dependent variables were the average occlusal Tooth Wear Index (TWI) and the average of the surfaces with the maximum Tooth Wear Evaluation System 2.0 score (TWES). Univariate and multivariate linear regression models were utilized, including a multivariate analysis without outliers. Sex and age were added as confounders. Results: A total of 159 patients were included in this study. The average age of the individuals was 37.1 (± 9.1) years and 34 (21 %) were female. Univariate models showed a statistically significant association between both TWI and SWS pH. Multivariate models showed that the negative associations between SWS (β = -0.20, C.I. = -0.36 - -0.03 [TWI]; β = -0.12, C.I. = -0.22 - -0.02 [TWES]) and UWS pH (β = -0.12, C.I. = -0.26 - 0.02 [TWI]; β = -0.09, C.I. = -0.18 - 0.00 [TWES]) and tooth wear were largely unaffected by confounders. These associations were also robust against outliers. A relevant association with flow rate was not detected. Conclusion: This study shows that salivary pH was inversely associated with tooth wear severity even after correction for confounders, such as flow rate, age, and sex. This association was especially significant for SWS. Although no causal relationship can be established, the results suggest a role of salivary pH in tooth wear in patients with moderate to severe tooth wear. No association was found between tooth wear and flow rate.

Meetings

Scientific presentations and posters at the Dutch Dental Science days 2024

1. Mees de Jong, ACTA – Improving Oral Health Care for Community-dwelling Frail Older People through Interprofessional Collaboration: Identifying Barriers, Success Factors, and Integration Strategies
2. Sanne Pruntel, UMCG / RUG – Oral health in patients with cognitive complaints at a Dutch memory clinic
3. Mark Laske, Radboudmc – Data exchange between oral care practice and general practice: a scoping review and qualitative research
4. Hanan al Habobe, ACTA – Exploring Saliva Biomarkers for Obesity Diagnosis and Preventive Healthcare
5. Victor Madariaga, Radboudmc – In vitro and in situ validation of ISFET sensor for intraoral pH monitoring: Preliminary results
6. Joanita van Santen, ACTA – Intra-Oral Ion Concentration Measurements in Healthy Individuals
7. Isabelle Bos, Nivel – Connecting routine healthcare data from dental care and general practice: First results and opportunities from a data linkage study
8. Joanita van Santen: Salivary Intra-Oral Ion Concentrations in Healthy Individuals. (Poster)

Scientific presentations and posters at the Dutch Dental Science days 2025

1. Mees de Jong, ACTA – ‘Development of a Short screening Tool pRedicting Oral Health deterioration in older people by the general practitioner (SHORT)’
2. Mark Laske, RadboudUMC – The association between polypharmacy and caries prevalence in dental practices in the Netherlands.
3. Elena Stamatelou, ACTA – Machine Learning Modeling for Severe Periodontitis Prediction Using Self-Reported Oral Health Questionnaires within the ORANGE-FORCE project.
4. Victor Madariaga, RadboudUMC – Preclinical validation of an ISFET device for intraoral pH monitoring: Preliminary results from a healthy subject.
5. Hanan Al Habobe, HU / ACTA – IL-6, Calcium, sAA, and Cortisol as a Salivary Biomarker-Combination Associated with Obesity: A Pilot Study
6. Joanita van Santen, ACTA – The Intra-Oral Variations of Salivary Ions