Saliva as a biomarker for dental caries: A systematic review

Prevalence of dental caries among coronavirus disease 2019-recovered patients and correlation with salivary total antioxidant capacity in Kalaburagi region of Indian subpopulation

Background

Coronavirus disease 2019 (COVID-19) has vastly affected mankind worldwide, and its long-term effect on oral health needs to be studied.

Aims

The aim of the study was to evaluate the prevalence of dental caries and its correlation with salivary total antioxidant capacity (TAC) in Kalaburagi region of the Indian subpopulation.

Methods

About 80 subjects (16-55 years) were included in the study based on selection criteria and were divided into two groups (n = 40). Group 1: no history of COVID-19 infection and Group 2: COVID-19-recovered subjects. Each group was subdivided into two subgroups (n = 20) A and B with and without dental caries. Dental caries was assessed using the decay, missing, filled, treatment (DMFT) index by the World Health Organization. About 5 ml of unstimulated saliva samples was collected and centrifuged at 2000 rpm for 10 min, and the supernatants were collected. Salivary TAC was estimated using 2,2'-azino-bis-[3-ethylbenzothiazoline-6-sulfonic] acid assay and observed under spectrophotometer (734 nm).

Statistical Analysis

Data were analyzed using the Shapiro-Wilk test for normality distribution followed by one-way analysis of variance and post hoc Tukey test (P < 0.05).

Results

COVID-19-recovered subjects showed a higher prevalence of dental caries and lower TAC levels than non-COVID-19 subjects.

Conclusion

Higher prevalence of dental caries with lower levels of salivary TAC was found in COVID-19-recovered individuals.

Effect of fluoride varnishes on oral bacteria of preschool children with cavitated and non-cavitated carious lesions: randomized clinical trial

We compare the effect of calcium and phosphate-containing sodium fluoride (NaF) varnishes to conventional NaF varnish on S. mutans and L. fermentum counts. 3-4 years old children were grouped according to their caries status (n = 45 each): caries-free, with non-cavitated and with cavitated lesions. Each group was randomly subdivided (n = 15 each) into: Group 1- 5% NaF, Group 2- 5% NaF with tricalcium phosphate, Group 3- 5% NaF with casein phosphopeptide- amorphous calcium phosphate. Biofilm and saliva were collected to quantify microorganisms at baseline (T1) and 24-months (T2). Differences between groups were compared using Kruskal-Wallis test, followed by Dunn-Bonferroni post-test, at 0.0167 α-level. Significant difference was found for percentage of children with detectable biofilm L. fermentum (p = 0.013) at T1 and salivary S. mutans (p = 0.011) at T2. Percentage of children increased from T1 to T2 in Group 2 with salivary S. mutans (p = 0.007), salivary L. fermentum (p = 0.035), and biofilm L. fermentum (p = 0.019) and in Group 3 with salivary L. fermentum (p = 0.035). Bacterial change was not significant in both samples of intervention groups, except increase in salivary S. mutans (p = 0.038) in Group 3. Both calcium- and phosphate-containing NaF varnishes demonstrated similar antibacterial effect on S. mutans and L. fermentum compared to conventional NaF varnish.

Type 1 diabetes, glycemic traits, and risk of dental caries: a Mendelian randomization study

Background: Regarding past epidemiological studies, there has been disagreement over whether type 1 diabetes (T1DM) is one of the risk factors for dental caries. The purpose of this study was to determine the causative links between genetic susceptibility to T1DM, glycemic traits, and the risk of dental caries using Mendelian randomization (MR) approaches. Methods: Summary-level data were collected on genome-wide association studies (GWAS) of T1DM, fasting glucose (FG), glycated hemoglobin (HbA1c), fasting insulin (FI), and dental caries. MR was performed using the inverse-variance weighting (IVW) method, and sensitivity analyses were conducted using the MR-Egger method, weighted median, weighted mode, replication cohort, and multivariable MR conditioning on potential mediators. Results: The risk of dental caries increased as a result of genetic susceptibility to T1DM [odds ratio (OR) = 1.044; 95% confidence interval (CI) = 1.015-1.074; p = 0.003], with consistent findings in the replication cohort. The relationship between T1DM and dental caries was stable when adjusted for BMI, smoking, alcohol intake, and type 2 diabetes (T2DM) in multivariable MR. However, no significant correlations between the risk of dental caries and FG, HbA1c, or FI were found. Conclusion: These results indicate that T1DM has causal involvement in the genesis of dental caries. Therefore, periodic reinforcement of oral hygiene instructions must be added to the management and early multidisciplinary intervention of T1DM patients, especially among adolescents and teenagers, who are more susceptible to T1DM.

Six-month follow-up of salivary antioxidant defense outcomes of individuals using medicated toothpaste

Objective

The objective of this study was to study the effect of medicated toothpaste on oral health, a 6-month follow-up.

Methods

Four hundred and twenty-seven participants were screened and followed up for 6 months. The intraoral examination was performed to record caries, gingival bleeding, and plaque index. Saliva collected was evaluated for pH, total antioxidant capacity (TAC), malondialdehyde (MDA), and Vitamin C level for 6 months, and data were analyzed.

Results

On the usage of medicated toothpaste with herbal extract for 6 months, the salivary pH levels were increased, the interquartile range for plaque, and the gingival bleeding index decreased. The percentage change in salivary TAC, MDA, and Vitamin C levels in the caries-free group of subgroup I was 174.8, 58.06, and 59.98, respectively, in subgroup II was 133.3, 52.08, and 58.51, and in subgroup III was 63.77, 45.11, and 47.77. The percentage change in salivary TAC, MDA, and Vitamin C levels in the caries-active group of subgroup I was 136.62, 57.27, and 72.83, subgroup II was 108.59, 37.50, and 61.55, and in subgroup III was 35.62, 30.82, and 54.10, respectively.

Conclusion

The salivary pH levels increased on the usage of medicated toothpaste with herbal extract; plaque and the gingival bleeding index scores were decreased. The salivary antioxidant defense was increased in individuals using medicated toothpaste with herbal extracts which signifies an improvement in overall oral health in the 6-month follow-up.

Oral functional impairment may cause malnutrition following oral cancer treatment in a single-center cross-sectional study

Oral dysfunction and dysphagia after oral cancer treatment are linked to altered nutritional status. We aimed to identify specific oral functions related to nutritional status. We conducted a cross-sectional study from September 2019 to December 2021, recruited 75 participants (median age: 72.0 years), including 52 males and 23 females, collected background data, and evaluated oral function. The Mini Nutritional Assessment-Short Form (MNA-SF) scores were divided into three groups (normal nutritional status, at risk of malnutrition, and malnourished), and a multi-group comparison was conducted for each oral function measurement (microorganisms, oral dryness, occlusal force, tongue pressure, masticatory function, and Eating Assessment Tool [EAT-10]). The primary tumor site was the tongue in 31 patients (41.3%), gingiva in 30 (40.0%), and others in 14 (18.7%). Multiple comparisons revealed significant differences in occlusal force, tongue pressure, masticatory function, and EAT-10 levels, categorized as Type I (Transport type) and Type III (Occlusion type) postoperative oral dysfunctions, between each MNA-SF group. Multiple regression analysis showed a statistically significant association with MNA-SF in terms of masticatory function and EAT-10 levels, categorized as Type I. Type I and Type III are risk factors for malnutrition, confirming that different types of postoperative oral dysfunction require unique nutritional guidance.

Application of a Novel Biosensor for Salivary Conductivity in Detecting Chronic Kidney Disease

The prevalence of chronic kidney disease (CKD) is increasing, and it brings an enormous healthcare burden. The traditional measurement of kidney function needs invasive blood tests, which hinders the early detection and causes low awareness of CKD. We recently designed a device with miniaturized coplanar biosensing probes for measuring salivary conductivity at an extremely low volume (50 μL). Our preliminary data discovered that the salivary conductivity was significantly higher in the CKD patients. This cross-sectional study aims to validate the relationship between salivary conductivity and kidney function, represented by the estimated glomerular filtration rate (eGFR). We enrolled 214 adult participants with a mean age of 63.96 ± 13.53 years, of whom 33.2% were male. The prevalence rate of CKD, defined as eGFR < 60 mL/min/1.73 m2, is 11.2% in our study. By multivariate linear regression analyses, we found that salivary conductivity was positively related to age and fasting glucose but negatively associated with eGFR. We further divided subjects into low, medium, and high groups according to the tertials of salivary conductivity levels. There was a significant trend for an increment of CKD patients from low to high salivary conductivity groups (4.2% vs. 12.5% vs. 16.9%, p for trend: 0.016). The receiver operating characteristic (ROC) curves disclosed an excellent performance by using salivary conductivity combined with age, gender, and body weight to diagnose CKD (AUC equal to 0.8). The adjusted odds ratio of CKD is 2.66 (95% CI, 1.10−6.46) in subjects with high salivary conductivity levels. Overall, salivary conductivity can serve as a good surrogate marker of kidney function; this real-time, non-invasive, and easy-to-use portable biosensing device may be a reliable tool for screening CKD.

Effects of Fluoride and Calcium Phosphate-Based Varnishes in Children at High Risk of Tooth Decay: A Randomized Clinical Trial

BACKGROUND

The aim of this study was to investigate the effect of the application of two varnishes-MI Varnish (5% sodium fluoride with CPP-ACP) and Clinpro White Varnish (5% sodium fluoride with fTCP)-applied every three months in children with high caries risk for 12 months on plaque indexes, salivary pH, salivary lactic acid and chemical elements concentrations.

METHODS

We included 58 children aged 4-12 years, assigned to control (placebo), Clinpro and MI groups. Baseline and three-month saliva samples were taken. We assessed changes in pH, lactic acid concentrations and chemical elements in saliva.

RESULTS

At 12 months, all groups showed a nonsignificant increase in pH levels and a reduction in lactic acid, which was greatest in the placebo group. There was a significant reduction in ²⁴Mg (p = <0.001), ³¹P (p = 0.033) and ⁶⁶Zn (p = 0.005) levels in the placebo group (p ≤ 0.05), but not in the other elements studied: ²³Na, ²⁷Al, ³⁹K, ⁴⁴Ca, ⁵²Cr, ⁵⁵Mn, ⁵⁷Fe, ⁵⁹Co, ⁶³Cu, ⁷⁵As, ¹¹¹Cd, ¹³⁷Ba, ²⁰⁸Pb and ¹⁹F.

CONCLUSIONS

Neither pH, lactic acid concentrations or most salivary chemical elements were useful in defining patients at high risk of caries or in monitoring the effect of MI Varnish and Clinpro White Varnish after three-month application for 12 months. However, the appearance of new cavities was stopped, and the hygiene index improved, probably due to hygienic and dietary measures and the use of fluoridated toothpaste.

TRIAL REGISTRATION

ISRCTN registry, ISRCTN13681286.

Estimation of Copper Levels in Saliva and Its Relation to Dental Caries and Hemoglobin Levels

Context

A very small quantity of trace elements will be present in saliva. Salivary composition influences caries inhibition and promotion based on the different organic, inorganic, and trace elements.

Aim and objective

To evaluate the levels of copper in saliva in children with caries-active and caries-free group and to associate copper levels of saliva with hemoglobin (Hb) levels of blood.

Materials and methods

Sixty subjects between the ages of 6 and 14 years were divided into group I—caries-free and group II—caries-active. The caries-active group was further subdivided into group IIa (deft/DMFT < 3) and group IIb (deft/DMFT > 3). To maintain the uniformity of salivary composition, unstimulated saliva (5 mL) was collected in noontime before food from all the participants. The copper levels were estimated by atomic absorption spectrophotometry. Hemoglobin levels in the blood and their relation with copper levels in saliva were estimated.

Statistical analysis

The results thus obtained were analyzed by t-test and Karl Pearson's correlation coefficient. It was considered significant if the “p” value is 0.05 or less.

Results

Copper levels were higher in group II showing statistically highly significant results compared with that of group I with p ≤ 0.00001. The results were no significant with respect to Hb scores among the groups.

Conclusion

A definite positive correlation is seen with dental caries and levels of copper in saliva. Hence, the amount of copper in saliva can be considered as a caries risk assessment tool.

How to cite this article

Reddy VR, Devakar S, Chowdhary N, et al. Estimation of Copper Levels in Saliva and Its Relation to Dental Caries and Hemoglobin Levels. Int J Clin Pediatr Dent 2021;14(2):235–237.

Downregulation of Salivary Proteins, Protective against Dental Caries, in Type 1 Diabetes

Saliva, an essential oral secretion involved in protecting the oral cavity’s hard and soft tissues, is readily available and straightforward to collect. Recent studies have analyzed the salivary proteome in children and adolescents with extensive carious lesions to identify diagnostic and prognostic biomarkers. The current study aimed to investigate saliva’s diagnostic ability through proteomics to detect the potential differential expression of proteins specific for the occurrence of carious lesions. For this study, we performed bioinformatics and functional analysis of proteomic datasets, previously examined by our group, from samples of adolescents with regulated and unregulated type 1 diabetes, as they compare with healthy controls. Among the differentially expressed proteins relevant to caries pathology, alpha-amylase 2B, beta-defensin 4A, BPI fold containing family B member 2, protein S100-A7, mucin 5B, statherin, salivary proline-rich protein 2, and interleukin 36 gamma were significantly downregulated in poorly-controlled patients compared to healthy subjects. In addition, significant biological pathways (defense response to the bacterium, beta-defensin activity, proline-rich protein activity, oxygen binding, calcium binding, and glycosylation) were deregulated in this comparison, highlighting specific molecular characteristics in the cariogenic process. This analysis contributes to a better understanding of the mechanisms involved in caries vulnerability in adolescents with unregulated diabetes.

A Randomized, Double-Blind, Placebo-Controlled, Cross-Over Study to Evaluate the Efficacy of AqualiefTM Mucoadhesive Tablets in Head and Neck Cancer Patients Who Developed Radiation-Induced Xerostomia

Xerostomia, the subjective complaint of dry mouth, is caused by therapeutic interventions or diseases. Nowadays, radiotherapy (RT) in patients with head and neck cancer (HNC) stands out as one of the most important causes of xerostomia. Currently available therapies for the treatment of xerostomia are still less than optimal and xerostomia still represents an unmet clinical need. In this article, we present the results of a prospective clinical study with a new product, Aqualief^TM, in patients treated with curative RT with or without chemotherapy for HNC. Aqualief^TM is based on two main ingredients, carnosine and karkadé, which have acid buffering and antioxidant properties. The study was performed on 30 patients, with 4 of the patients being lost during the study period. Each patient received randomly one of the two treatments, Aqualief^TM or placebo, for 8 days. After a 10-day wash-out period, each patient received the other treatment for a further 8 days. The results show that Aqualief^TM stimulated salivation in these patients and reduced the pH drop that was observed in an equivalent placebo-treated population of patients. Moreover, no serious, treatment-related adverse events were observed. Aqualief^TM has shown positive results, although with limitations due to unsuccessful trial accrual. Therefore, it may be further investigated as a tool for the treatment of RT-related xerostomia.

Salivary biochemical indices related to early childhood caries

OBJECTIVES

This study aimed to compare the salivary biochemical indices between caries-free individuals and those with early childhood caries (ECC), and construct a saliva-based caries diagnostic model by analyzing the correlation between salivary biochemical indices and caries severity.

METHODS

A total of 120 children aged 4-6 years were selected and divided into two groups: individuals with ECC (C group, n=60) and healthy children (H group, n=60). Salivary samples were collected to compare the pH, total protein, and ion concentrations between the two groups. The correlation between the salivary biochemical indices and caries severity was examined, and an ECC diagnostic model was established.

RESULTS

The NO₃^- concentration significantly decreased in the C group, whereas the Cl^-, Br^-, NH₄⁺, and Mg²⁺ concentrations significantly increased in the C group (P<0.05). In addition, the salivary caries severity had a significantly negative correlation with the NO₃^- concentration but had a positive correlation with Br^-, Cl^-, and NH₄⁺ concentrations (P<0.05). The ECC diagnostic model based on salivary biochemical indices could yield satisfactory results in terms of distinguishing the C and H groups with over 85% accuracy.

CONCLUSIONS

Salivary biochemical indices can contribute to the diagnosis and risk assessment of ECC.

The Impact of Sport Training on Oral Health in Athletes

Athletes' oral health appears to be poor in numerous sport activities and different diseases can limit athletic skills, both during training and during competitions. Sport activities can be considered a risk factor, among athletes from different sports, for the onset of oral diseases, such as caries with an incidence between 15% and 70%, dental trauma 14-70%, dental erosion 36%, pericoronitis 5-39% and periodontal disease up to 15%. The numerous diseases are related to the variations that involve the ecological factors of the oral cavity such as salivary pH, flow rate, buffering capability, total bacterial count, cariogenic bacterial load and values of secretory Immunoglobulin A. The decrease in the production of S-IgA and the association with an important intraoral growth of pathogenic bacteria leads us to consider the training an "open window" for exposure to oral cavity diseases. Sports dentistry focuses attention on the prevention and treatment of oral pathologies and injuries. Oral health promotion strategies are needed in the sports environment. To prevent the onset of oral diseases, the sports dentist can recommend the use of a custom-made mouthguard, an oral device with a triple function that improves the health and performance of athletes. During training, the sports dentist must monitor the athletes and the sports examination protocol must be implemented with the inclusion of the clinical examination, quantitative and qualitative analysis of saliva and instructions on the use, cleansing and storage of the mouthguard.

Association of Hormonal Fingerprints and Dental Caries: A Pilot Study

Context:

Dental caries remains the most widespread oral disease among all age groups. Hormonal fingerprints (second digit: fourth digit ratio or 2D:4D ratio) are biomarkers displaying sexual dimorphism and diverse human phenotypic traits. A person's genetic makeup may influence the occurrence of dental caries.

Aim:

The present study aimed to evaluate the influence of digit ratio on the incidence of dental caries.

Settings and Design:

Two hundred patients between 18 and 55 years, reporting for restorations or endodontic therapy, participated in the study.

Subjects and Methods:

Hormonal fingerprints (2D:4D ratio) were measured with the help of a digital vernier caliper. Caries incidence was recorded using the DMFT index.

Statistical Analysis used:

Data obtained were tabulated and statistically analyzed using Independent t-test and Chi-square test.

Results

Males had a less mean 2D:4D ratio than females, which was statistically significant (p-value = 0.003). Chi-square test was applied, and there was a statistically significant correlation between high digit ratio and caries experience (p-value = 0.002). Females with a high digit ratio and males with a low digit ratio were in the moderate and low caries risk groups with a p-value of 0.029 and 0.001 in the respective risk groups.

Conclusion

The present study displayed a correlation between hormonal fingerprints (2D:4D ratio) and dental caries. An indicator of caries risk will help prevent caries by implementing oral hygiene measures, which will reduce its incidence as the most occurring oral disease.

Dental caries in primary and permanent teeth in children's worldwide, 1995 to 2019: a systematic review and meta-analysis

Background

Early childhood caries (ECC) is a type of dental caries in the teeth of infants and children that is represented as one of the most prevalent dental problems in this period. Various studies have reported different types of prevalence of dental caries in primary and permanent teeth in children worldwide. However, there has been no comprehensive study to summarize the results of these studies in general, so this study aimed to determine the prevalence of dental caries in primary and permanent teeth in children in different continents of the world during a systematic review and meta-analysis.

Methods

In this review study, articles were extracted by searching in the national and international databases of SID, MagIran, IranMedex, IranDoc, Cochrane, Embase, ScienceDirect, Scopus, PubMed, and Web of Science (ISI) between 1995 and December 2019. Random effects model was used for analysis and heterogeneity of studies was evaluated by using the I² index. Data were analyzed by using the Comprehensive Meta-Analysis (Version 2) software.

Findings

In this study, a total of 164 articles (81 articles on the prevalence of dental caries in primary teeth and 83 articles on the prevalence of dental caries in permanent teeth) were entered the meta-analysis. The prevalence of dental caries in primary teeth in children in the world with a sample size of 80,405 was 46.2% (95% CI: 41.6–50.8%), and the prevalence of dental caries in permanent teeth in children in the world with a sample size of 1,454,871 was 53.8% (95% CI: 50–57.5%). Regarding the heterogeneity on the basis of meta-regression analysis, there was a significant difference in the prevalence of dental caries in primary and permanent teeth in children in different continents of the world. With increasing the sample size and the year of study, dental caries in primary teeth increased and in permanent teeth decreased.

Conclusion

The results of this study showed that the prevalence of primary and permanent dental caries in children in the world was found to be high. Therefore, appropriate strategies should be implemented to improve the aforementioned situation and to troubleshoot and monitor at all levels by providing feedback to hospitals.

Salivary Redox Biomarkers in Selected Neurodegenerative Diseases

Neurodegenerative diseases (NDDs), such as Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease, are disorders, which cause irreversible and progressive deterioration of the central nervous system. The pathophysiology of NDDs is still not fully explained; nevertheless, oxidative stress is considered as a critical mediator of cerebral degeneration, brain inflammation, as well as neuronal apoptosis. Therefore, it is not surprising that redox biomarkers are increasingly used in the diagnosis of neurodegenerative diseases. As saliva is a very easy to obtain bioliquid, it seems promising to use this biomaterial in the diagnosis of NDDs. Saliva collection is easy, cheap, stress-free, and non-infectious, and it does not require the help of a specialised medical personnel. Additionally, the concentrations of many salivary redox biomarkers correlate with their content in blood serum as well as the degree of disease progression, which makes them non-invasive indicators of NDDs. This paper reviews the latest knowledge concerning the use of salivary redox biomarkers in the diagnosis and prognosis of selected neurodegenerative diseases.