Co-relationships between glandular salivary flow rates and dental caries

Nicotinamide mononucleotide suppresses cellular senescence and increases aquaporin 5 expression in the submandibular gland of aged male mice to ameliorate aging-related dry mouth

Dry mouth results from decreased saliva secretion due to aging or drug side effects. Decreased saliva secretion causes dryness in the oral cavity that makes swallowing difficult and increases the risk of aspiration pneumonia. There are few fundamental treatments for dry mouth. Here we investigated whether treatment of old mice with nicotinamide mononucleotide (NMN) improved factors associated with dry mouth. Young (16-week-old) and old (113-week-old) male mice were treated subcutaneously with saline or NMN (300 mg/kg) once every two days for four weeks and saliva secretion was measured. The amount of nicotinamide adenine dinucleotide (NAD+) in salivary gland tissues was measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Gene expression in the intestinal tract and salivary glands was measured by real-time PCR. The population of cells with acetylation in the submandibular gland was quantified by immunohistological staining. SA-β-gal activity in the submandibular gland was measured to assess cell senescence. Statistical analysis was performed by one-way analysis of variance with Tukey post hoc analysis. The submandibular glands from old mice treated with NMN exhibited increased saliva secretion and NAD+ levels, which both decrease with aging. In addition, the submandibular glands from NMN-treated old mice had decreased acetylation, numbers of senescent cells, and levels of senescence-associated secretory phenotype (SASP) factors, which all increase with aging, as well as increased aquaporin5 (AQP5) mRNA expression. NMN administration may improve dry mouth by regulating cellular senescence in the submandibular gland and increasing expression of AQP5, a water channel involved in saliva secretion, to inhibit age-related decreases in saliva secretion. It is necessary to elucidate further mechanism and confirm its effectiveness in humans.

Association of Anthropometric Measurements, Hemoglobin Level and Salivary Parameters among Caries-free and S-ECC Children

Context

The implication of severe dental caries in children may have its effect on general health apart from affecting the orodental tissues. Many children reporting with severe caries have shown weighing less due to malnourishment resulting in anemia and modified somatic growth.

Aims

Study aimed to assess and compare anthropometric measurements, hemoglobin level, and salivary parameters among caries-free and severe early childhood caries (E-CCC) children.

Settings and design

For caries-free group [Group I] and S-ECC group [Group II] data were obtained from age-matched children with similar socioeconomic status.

Materials and methods

Children with severe caries and without caries from the age-group 3- 6 years participated in the study. Children were measured for height, weight, measurement of mid-upper arm circumference, and waist circumference. Hemoglobin level was recorded. The collected unstimulated saliva was assessed for flow rate, salivary pH, and its buffering capacity.

Statistical analysis used

Both descriptive and inferential statistical analyses were carried out using Windows software and SPSS (21). Tests of significance namely t-test and Chi-square test were used along with regression analysis.

Results

Caries experience showed no statistical difference for age and gender among the sample population. Significant difference was found for all anthropometric measurements. When comparison for hemoglobin was done for both groups I and II, significant difference was observed [p = 0.003].

Conclusion

Children with severe dental caries in the present study had low hemoglobin which, if persisted, can lead to anemia. Though the anthropometric parameters may appear normal in children diagnosed with severe early childhood caries, pediatric dentist should ensure the hemoglobin level test, as iron deficiency can affect growth and development of the child, if left undiagnosed.

How to cite this article

Deshpande AN, Sudani U, Wadhwa M, et al. Association of Anthropometric Measurements, Hemoglobin Level and Salivary Parameters among Caries-free and S-ECC Children. Int J Clin Pediatr Dent 2022;15(S-2):S164-S171.

Dental Restorative Materials for Elderly Populations

The incidence of dental caries, especially root caries, has risen in elderly populations in recent years. Specialized restorative materials are needed due to the specific site of root caries and the age-related changes in general and oral health in the elderly. Unfortunately, the restorative materials commonly used clinically cannot fully meet the requirements in this population. Specifically, the antibacterial, adhesive, remineralization, mechanical, and anti-aging properties of the materials need to be significantly improved for dental caries in the elderly. This review mainly discusses the strengths and weaknesses of currently available materials, including amalgam, glass ionomer cement, and light-cured composite resin, for root caries. It also reviews the studies on novel anti-caries materials divided into three groups, antimicrobial, remineralization, and self-healing materials, and explores their potential in the clinical use for caries in the elderly. Therefore, specific restorative materials for caries in the elderly, especially for root caries, need to be further developed and applied in clinical practice.

A Prospective Cohort Study Assessing the Impact of Fixed Orthodontic Appliances on Saliva Properties and Oral Microbial Flora

PURPOSE

Orthodontic treatment may introduce a risk to the integrity of enamel due to plaque accumulation and colonisation by oral microbes. This prospective cohort study observed the effect of fixed, self-ligating orthodontic appliances on saliva properties and oral microbial flora. Materials and Methods: Thirty adolescent patients were recruited (13 female, 17 male, mean age 13.97 ± 2.07 years). Saliva samples were collected before placement of fixed orthodontic appliances (T0), and 4 (T1) and 12 (T2) weeks later. Salivary pH, flow rate and buffering capacity were recorded. All saliva samples were cultured on agar plates for 2 days. Salivary prevalence of Neisseria spp., streptococci, Staphylococcus aureus, coagulase-negative staphylococci and Candida albicans were assessed. Results: High buffering capacity was reported in 21 patients at T0, 22 patients at T1 and in 28 patients at T2. Saliva flow rate also increased over time (7.08 ml/5 min at T0, 7.93 ml/5 min at T1 and 8.35 ml/5min at T2). Mean pH was 7.63 at T0, 7.67 at T1 and 7.78 at T2. There was no evidence that either pH or the number of colonies of any of the microbial species changed over time. Conclusion: The increased buffering capacity of saliva as well as the salivary flow rate after initial bonding might be protective against the development of dental caries. Current microbial findings indicate that initiation of orthodontic treatment may not be associated with significant changes in oral microbial flora.

Salivary flow rate, pH and buffering capacity in patients undergoing fixed orthodontic treatment - A prospective study

Background

Human saliva has got many important functions like lubrication of the oral tissues, making oral functions like speech, mastication and deglutition possible and also protecting teeth and oral mucosal surfaces in different ways. Dental Caries is one of the common complications in patients undergoing orthodontic treatment. Subjects with impaired saliva flow rate often show high caries incidence. A low flow rate combined with a low or moderate buffer effect clearly indicates poor salivary resistance against microbial attack.

Aim

To investigate the changes in stimulated and unstimulated salivary flow rate, pH and buffer capacity in patients undergoing therapy with fixed orthodontic appliances.

Materials and Methods

Salivary flow rate, pH and buffering capacity of 20 patients who underwent fixed orthodontic treatment at Department of Orthodontics, Ragas Dental College and Hospital, Chennai were examined using GC saliva check buffer kit. The procedure was carried out during the initiation of orthodontic treatment and subsequently, one month and six months after the placement of appliance.

Results

Results showed there was a significant increase in the salivary flow rate one month and six months after placement of fixed appliance while pH and buffering capacity showed no significant changes.

Conclusion

Salivary flow rate increases significantly during fixed orthodontic treatment. Salivary pH and buffering capacity showed no significant changes suggesting that they are not sole factors for demineralization in orthodontic patients.

Current and Emerging Evidence for Toll-Like Receptor Activation in Sjögren's Syndrome

While the importance of Toll-like receptor (TLR) signaling is well established in many autoimmune diseases, the role of TLR activation in Sjögren's syndrome (SS) is poorly understood. Studies in mice and humans reveal that TLRs are potent mediators of inflammation in SS. TLRs are expressed and functional in salivary tissue, and TLRs in peripheral blood cells of SS patients are also upregulated and hyperresponsive to ligation. In this review, we will detail observations in mouse models regarding the importance of TLR activation in both local and systemic disease. We will then discuss studies in SS patients that provide evidence of the importance of TLR-mediated signaling in disease. While the ligands that activate TLRs in the context of SS are unknown, emerging data suggest that damage-associated molecular patterns (DAMPs) may be significant drivers of the chronic and unremitting inflammation that is characteristic of SS. We will discuss putative DAMPs that may be of clinical significance in disease. Therapies that target TLR signaling cascades will likely reduce both exocrine-specific and systemic manifestations of SS.

Gender-dependent associations between occupational status and untreated caries in Japanese adults

The aim of this study was to examine whether the presence of untreated caries is different across occupational status among Japanese adults. This was a cross-sectional survey of 1,342 individuals (990 males and 352 females) aged 40-64 yr who underwent medical and dental checkups at a healthcare center in 2011. Oral examination was performed by a dentist and the presence of untreated caries was defined as having at least one untreated decayed tooth. Data regarding current occupational status were obtained using a self-administered questionnaire; the participants were classified into five groups: professionals and managers, clerical and related workers, service and salespersons, agricultural, forestry, and fishery workers, and homemakers and unemployed. Gender-specific odds ratios (ORs) and 95% confidence intervals (CIs) of occupational status for the presence of untreated caries were estimated using logistic regression. After adjusting for potential confounders, female professionals and managers (OR=3.51, 95% CI=1.04-11.87) and service and salespersons (OR=5.29, 95% CI=1.39-20.11) had greater risks of the presence of untreated caries than female homemakers and unemployed. However, this tendency was not observed among males. In conclusion, there was a significant difference in risk of the presence of untreated caries by occupational status among females.

Salivary sCD14 as a potential biomarker of dental caries activity in adults

CD14 is a co-receptor involved in the recognition of Gram-negative and Gram-positive bacteria, the latter known to cause dental caries. The aim of this study was to determine whether soluble CD14 (sCD14) in saliva was associated with caries activity and the collection method from the saliva. The study included 55 participants aged 20 to 40 years, 30 with dental caries and 25 caries-free controls. We collected 110 saliva samples in total, 55 of resting saliva and 55 of mechanically stimulated saliva. Median levels of sCD14, measured with a matrix-matched enzyme-linked immunosorbent assay (ELISA), were higher in the caries-active than in the caries-free group in either resting (203.3 vs.167.9 ng mL-1; P<0.01) or stimulated saliva (201 vs.105.7 ng mL-1; P<0.01). The resting salivary flow rate was lower in the caries-active than caries-free group (0.61±0.42 vs. 0.98±0.52 mL min-1; P<0.01). Hyposalivation was observed only in the caries-active group (10 and 13 % in stimulated and resting saliva, respectively). Higher salivary sCD14 levels and secretion rates were clearly associated with dental caries and resting saliva. Future studies should focus on the clinical utility of salivary sCD14 as a potential biomarker and predictor of future caries events.

Salivary Immune and Metabolic Marker Analysis (SIMMA): A Diagnostic Test to Predict Caries Risk

By using ELISA and colorimetric tests, we have measured 25 compounds in individuals with and without dental caries at different time points of dental biofilm formation and time of the day. We find that some compounds appear to be affected by circadian rhythms, others by dental plaque maturity, and others show constant values during a 24 h period. Using univariate analysis and cross-validation techniques, we have selected six components measured at specific time points that maximize the diagnostic separation of health and disease conditions. Two out of the six selected compounds are related to immune competence, another two to the adhesion capacity of micro-organisms, and another two to acid production or pH buffering. We conclude that, in order to design a robust caries risk test, the time of saliva sampling must be standardized and biomarkers from different categories must be included. The preliminary data shown in this paper provide a proof of principle of a caries risk test based on risk-associated categories. Thus, the test will provide not only a general caries risk assessment, but also the likely biological origin of that risk, namely: immune imbalance, and/or a tendency to adhesion of cariogenic organisms, and/or a lack of acid buffering. When tested longitudinally and validated in larger cohorts, this could open the possibility to develop preventive and personalized treatments.

Effect of saliva collection methods and oral hygiene on salivary biomarkers

The aim of this study was to evaluate the influence of unstimulated and stimulated saliva collection methods, as well as tooth brushing, on the secretion rate of salivary total protein, nitrite, total antioxidant capacity and alpha-amylase. Saliva of 14 healthy individuals were collected with stimulation using Salivette^®, Parafilm^® and chewing gum and without stimulation from spit with and without fluid accumulation, before and after oral hygiene. Total protein, nitrite, total antioxidant capacity and alpha-amylase concentration (sAA) were evaluated. The collection of saliva stimulated with Parafilm^® and chewing gum increased the salivary flow (1.5 ± 0.4 and 3.4 ± 0.7 mL/min, respectively) and the secretion rate of salivary total protein (1.0 ± 0.2 and 2.3 ± 0.5 mg/min, respectively). Also, chewing gum increases the salivary nitrite secretion (213 ± 58 nmol/min) and total antioxidant capacity (410 ± 47 nmol trolox eq/min). Interestingly, the unstimulated method without saliva accumulation prior to collection resulted in low sAA levels (23,531 ± 7979 pixel density). Furthermore, oral hygiene decreased salivary flow (1.3 ± 0.5 to 1.0 ± 0.4 mL/min), reduced the secretion rate of total protein (1.0 ± 0.5 to 0.6 ± 0.2 mg/min, p < .05) and increased sAA (13,159 ± 7114 to 20,075 ± 25,656 pixel density, p < .05). The type of stimulation can activate autonomous receptors responsible for the secretion and composition of saliva. Therefore, the evaluation of saliva collection methods and oral hygiene on salivary biomarkers is important for understanding and standardizing variations in salivary composition to strengthen the use of saliva as a diagnostic fluid.

[Difficulty influence factors of dental caries clinical treatment]

Dental caries is a major disease that threaten human's oral healthy severely with the characteristics of high incidence, low rate of treatment and high rate of retreatment. At present, restorative treatment remains the main method for caries treatment. With the development of the Minimally Invasive Cosmetic Dentistry (MICD), reasonable application of various treatment technologies, maximum preservation of tooth tissues and realizing the maximization of treatment effects become problems that call for immediate solution in dental clinics. In addition, there still exist a large number of old restorations that need standard retreatments. Here, some difficulty influence factors of dental caries clinical treatment such as systemic and oral factors, individual caries susceptibility, treatment technologies and materials, retreatment methods of old restorations and technique sensitivity are analyzed, and corresponding processing strategies are also put forward.