Saliva and dental health. Clinical implications of saliva: report of a consensus meeting

A systematic review of salivary biomarkers in Parkinson's disease

The search for reliable and easily accessible biomarkers in Parkinson's disease is receiving a growing emphasis, to detect neurodegeneration from the prodromal phase and to enforce disease-modifying therapies. Despite the need for non-invasively accessible biomarkers, the majority of the studies have pointed to cerebrospinal fluid or peripheral biopsies biomarkers, which require invasive collection procedures. Saliva represents an easily accessible biofluid and an incredibly wide source of molecular biomarkers. In the present study, after presenting the morphological and biological bases for looking at saliva in the search of biomarkers for Parkinson's disease, we systematically reviewed the results achieved so far in the saliva of different cohorts of Parkinson's disease patients. A comprehensive literature search on PubMed and SCOPUS led to the discovery of 289 articles. After screening and exclusion, 34 relevant articles were derived for systematic review. Alpha-synuclein, the histopathological hallmark of Parkinson's disease, has been the most investigated Parkinson's disease biomarker in saliva, with oligomeric alpha-synuclein consistently found increased in Parkinson's disease patients in comparison to healthy controls, while conflicting results have been reported regarding the levels of total alpha-synuclein and phosphorylated alpha-synuclein, and few studies described an increased oligomeric alpha-synuclein/total alpha-synuclein ratio in Parkinson's disease. Beyond alpha-synuclein, other biomarkers targeting different molecular pathways have been explored in the saliva of Parkinson's disease patients: total tau, phosphorylated tau, amyloid-β1-42 (pathological protein aggregation biomarkers); DJ-1, heme-oxygenase-1, metabolites (altered energy homeostasis biomarkers); MAPLC-3beta (aberrant proteostasis biomarker); cortisol, tumor necrosis factor-alpha (inflammation biomarkers); DNA methylation, miRNA (DNA/RNA defects biomarkers); acetylcholinesterase activity (synaptic and neuronal network dysfunction biomarkers); Raman spectra, proteome, and caffeine. Despite a few studies investigating biomarkers targeting molecular pathways different from alpha-synuclein in Parkinson's disease, these results should be replicated and observed in studies on larger cohorts, considering the potential role of these biomarkers in determining the molecular variance among Parkinson's disease subtypes. Although the need for standardization in sample collection and processing, salivary-based biomarkers studies have reported encouraging results, calling for large-scale longitudinal studies and multicentric assessments, given the great molecular potentials and the non-invasive accessibility of saliva.

Permanent and decidua dentition as chronological biomarkers of heavy metal contamination: A review of the forensic literature

STATEMENT OF PROBLEM

Contamination with heavy metals (HM) has great environmental consequences in the environment due to lack of biodegradation, in addition, accumulation in living beings causes defects in tissues and organs, deteriorating their function and inducing a wide spectrum of diseases. Human biomonitoring consists of the periodic measurement of a certain chemical substance or metabolite in a particular population, using matrices that can be acute or chronic. Teeth are chronic matrices that have great characteristics of resistance and chronological storage of information. This review aims to identify the mechanisms, spatial location, and affinity of HM within teeth, along with understanding its applicability as a chronological record matrix in the face of HM contamination.

MATERIAL AND METHODS

A systematic search review was performed using the PubMed/Medline, Web of Science, and Scopus metasearch engines, and the terms "teeth" OR "dental" OR "tooth" AND "heavy metals" were intersected. Complete articles are included in Spanish, English and Portuguese without time restrictions, involving studies in humans or in vitro; Letters to the editor, editorials and those that did not refer to information on the incorporation and relationship of HM with the teeth were excluded.

RESULTS

837 published articles were detected, 91 were adjusted to the search objective, and 6 were manually included. Teeth are structures with a great capacity for information retention in the face of HM contamination due to low physiological turnover and their long processes of marked formations by developmental biorhythm milestones such as the neonatal line (temporal reference indicator). The contamination mechanisms inside the tooth are linked to the affinity of hydroxyapatite for HM; this incorporation can be in the soft matrix during the apposition phase or as part of the chemical exchanges between hydroxyapatite and the elements of the environment.

CONCLUSION

The teeth present unique characteristics of great resistance and affinity for HM, as well as a chronological biomarker for human biomonitoring, so they can be used as means of expertise or evidence to confirm or rule out a fact of environmental characteristics in the legal field.

Mass spectrometry-based proteomic approaches for salivary protein biomarkers discovery and dental caries diagnosis: A critical review

Dental caries is a multifactorial chronic disease resulting from the intricate interplay among acid-generating bacteria, fermentable carbohydrates, and several host factors such as saliva. Saliva comprises several proteins which could be utilized as biomarkers for caries prevention, diagnosis, and prognosis. Mass spectrometry-based salivary proteomics approaches, owing to their sensitivity, provide the opportunity to investigate and unveil crucial cariogenic pathogen activity and host indicators and may demonstrate clinically relevant biomarkers to improve caries diagnosis and management. The present review outlines the published literature of human clinical proteomics investigations on caries and extensively elucidates frequently reported salivary proteins as biomarkers. This review also discusses important aspects while designing an experimental proteomics workflow. The protein-protein interactions and the clinical relevance of salivary proteins as biomarkers for caries, together with uninvestigated domains of the discipline are also discussed critically.

Drooling may be Associated with Dysphagia Symptoms in Multiple Sclerosis

During the process of the multiple sclerosis (MS), persons with multiple sclerosis (PwMS) may experience drooling (sialorrhea) issues that are frequently disregarded. The exact cause of drooling in PwMS is poorly understood. This study aims to assess potential risk factors for drooling seen in PwMS. The study included 20 PwMS with drooling and 19 PwMS without drooling. The participants' sociodemographic data and clinical parameters were noted. To evaluate dysphagia, fatigue, and hypersalivation, the Dysphagia in Multiple Sclerosis Questionnaire (DYMUS), the Fatigue Severity Scale (FSS), and objective saliva flow rate measurement with cottons placed in Stensen ducts and under the tongue (swab test) were used, respectively. The study employed univariate and multivariate logistic regression models to identify the risk factors linked to drooling. Gender, age, disease duration, MS type, and Expanded Disability Status Scale scores did not differ between the two groups. There was a significant increase in the DYMUS and submandibular/sublingual (SM/SL) saliva flow rate values in PwMS with drooling (p = 0.009 and p = 0.019, respectively). However, in our study, hypersalivation was not observed in PwMS with or without drooling. In the univariate model, DYMUS, SM/SL saliva flow rate, and FSS were found to be risk factors for drooling in PwMS. But only DYMUS was shown to be a significant risk factor in the multivariate model obtained by the backward (Wald) elimination method (p = 0.023). Finally, our research is the first to demonstrate the relationship between drooling and the presence of dysphagia symptoms in PwMS. This is a very important study to determine the nature of drooling in PwMS. This finding shows that our study will serve as a reference for choosing the best method for drooling treatment.

Antibacterial properties and abrasion-stability: Development of a novel silver-compound material for orthodontic bracket application

PURPOSE

Bacteria-induced white spot lesions are a common side effect of modern orthodontic treatment. Therefore, there is a need for novel orthodontic bracket materials with antibacterial properties that also resist long-term abrasion. The aim of this study was to investigate the abrasion-stable antibacterial properties of a newly developed, thoroughly silver-infiltrated material for orthodontic bracket application in an in situ experiment.

METHODS

To generate the novel material, silver was vacuum-infiltrated into a sintered porous tungsten matrix. A tooth brushing simulation machine was used to perform abrasion equal to 2 years of tooth brushing. The material was characterized by energy dispersive X‑ray (EDX) analysis and roughness measurement. To test for antibacterial properties in situ, individual occlusal splints equipped with specimens were worn intraorally by 12 periodontal healthy patients for 48 h. After fluorescence staining, the quantitative biofilm volume and live/dead distribution of the initial biofilm formation were analyzed by confocal laser scanning microscopy (CLSM).

RESULTS

Silver was infiltrated homogeneously throughout the tungsten matrix. Toothbrush abrasion only slightly reduced the material's thickness similar to conventional stainless steel bracket material and did not alter surface roughness. The new silver-modified material showed significantly reduced biofilm accumulation in situ. The effect was maintained even after abrasion.

CONCLUSION

A promising, novel silver-infiltrated abrasion-stable material for use as orthodontic brackets, which also exhibit strong antibacterial properties on in situ grown oral biofilms, was developed. The strong antibacterial properties were maintained even after surface abrasion simulated with long-term toothbrushing.

Botulinum neurotoxin type A in the interdisciplinary treatment of sialorrhea in adults and children-update and practice recommendations

Sialorrhea is defined as a chronic excessive flow of saliva from the mouth, often with adverse consequences for health and quality of life of patients. In addition to currently used non-drug treatment and systemic drugs, intraglandular Botulinum Neurotoxin A (BoNT/A) injections have been examined in case studies, controlled trials and clinical practice. Two pivotal Phase III trials recently led to market approval in the USA and EU for IncobotulinumtoxinA [Xeomin®, IncoBoNT/A, Clostridium botulinum neurotoxin type A (150 kD), free from complexing proteins, Merz Pharmaceuticals GmbH] for treatment of chronic sialorrhea in adults and pediatric patients. This review provides a multidisciplinary approach to discuss the current state of sialorrhea therapy as well as benefits and current limitations of BoNT/A injections. A consensus regarding treatment recommendations made available to physicians in Germany in 2022 has now been updated here for presentation to an international audience. This review provides a framework including a flow chart for patient selection, recommendations for dosing and the injection process, as well as a discussion of therapeutic goals, long-term benefits and safety aspects. This review is aimed at supporting physicians in developing multidisciplinary and individualized treatment approaches to achieve optimal benefits for patients.

Xerostomia: An easily ignored symptom induced by induction chemotherapy in patients with nasopharyngeal carcinoma

BACKGROUND

To investigate the prevalence and predictive factors of xerostomia during induction chemotherapy (IC) in patients with nasopharyngeal carcinoma (NPC).

METHODS

We prospectively enrolled NPC patients who received IC between October 2020 and October 2021. The Visual Analogue Scale (VAS) and Xerostomia Inventory (XI) were used to evaluate the condition of xerostomia. The volume of the submandibular gland (SMG) was also calculated before and after IC.

RESULTS

Fifty-two patients were enrolled in this study. Of these patients, 32.7% (n = 17) experienced xerostomia before IC. There were 32 (61.5%) patients suffered from xerostomia after IC, including 21 (40.4%) patients with newly diagnosed xerostomia after IC and 11 (21.1%) patients complained their xerostomia aggravated in those with xerostomia before IC. The median XI scores increased from 11 (standard deviation [SD], 2.930) to 18 (SD 3.995), 16 (SD 3.605), and 17 (SD 4.331) after the first, second, and third cycles of IC, respectively. The median score of VAS also increased from 0 to 4 during the following three cycles of IC. In those with IC-related xerostomia, the SMG volume after IC was significantly decreased compared with those without IC-related xerostomia (P = 0.001). The reduction of the SMG volume after IC was the independent risk factor for xerostomia (P = 0.002).

CONCLUSION

Approximately two-thirds of NPC patients suffered from IC-related xerostomia and patients with a reduction of SMG volume after IC had a higher risk of xerostomia.

In vitro remineralization assessment of enamel subsurface lesions using different percentages of surface reaction-type pre-reacted glass-ionomer containing gum-based material

OBJECTIVE

To identify the remineralization activity of enamel subsurface lesions using different percentages of surface pre-reacted glass-ionomer (S-PRG) filler containing gum-base material.

METHODS

Gum extracts from gum-base materials containing 0wt%, 5wt%, and 10wt% S-PRG filler were prepared as GE0, GE5, and GE10, respectively. A total of 50 bovine enamel specimens were used, and the polished enamel surface of a 3 × 3 mm2 window area was exposed. The specimens were then subjected to a demineralization solution for seven days to create a subsurface enamel lesion. Remineralization was then conducted for seven days using a protocol whereby the specimens were immersed three times a day in prepared gum extracts (0wt%, 5wt%, and 10wt%) and artificial saliva of pH 7 (Control) for 20 min at 37 °C. Thereafter, remineralization assessment was performed by using Swept Source Optical Coherence Tomography (SS-OCT) and micro-computed tomography (μCT). Surface morphology and elemental analysis were conducted by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS).

RESULTS

The depths of the demineralized lesions in the GE5 and GE10 groups were significantly lower than those of the Control and the GE0 groups. SEM observations of the enamel surface morphology of the GE5 and GE10 groups indicated remineralization with S-PRG filler-related elements present.

CONCLUSION

The GE5 and GE10 S-PRG filler containing gum-base materials showed significantly improved surface remineralization and reduced demineralization of the enamel lesions. EDS analysis suggested that the released ions from the S-PRG filler might be responsible for surface remineralization.

CLINICAL SIGNIFICANCE

The S-PRG filler containing gum-base material may have a significant remineralization effect and improve the surface morphology of enamel subsurface lesions.

Analysis of salivary flow rate, biochemical composition, and redox status in orchiectomized spontaneously hypertensive rats

OBJECTIVE

This study aimed to analyze the salivary flow rate, biochemical composition, and redox status in orchiectomized spontaneously hypertensive rats (SHR) compared to normotensive Wistar rats.

DESIGN

Thirty-two young adult male SHR and Wistar (3-months-old) rats were randomly distributed into four groups; either castrated bilaterally (ORX) or underwent fictitious surgery (SHAM) as Wistar-SHAM, Wistar-ORX, SHR-SHAM, and SHR-ORX. Two months beyond castration, pilocarpine-induced salivary secretion was collected from 5-month-old rats to analyze salivary flow rate, pH, buffer capacity, total protein, amylase, calcium, phosphate, sodium, potassium, chloride, thiobarbituric acid reactive substances (TBARs), carbonyl protein, nitrite, and total antioxidant capacity.

RESULTS

The salivary flow rate was higher in the Wistar-ORX compared to the Wistar-SHAM group, while remaining similar between the SHR-SHAM and SHR-ORX groups. ORX did not affect pH and salivary buffer capacity in both strains. However, salivary total protein and amylase were significantly reduced in the Wistar-ORX and SHR-ORX compared to the respective SHAM groups. In both ORX groups, salivary total antioxidant capacity and carbonylated protein were increased, while lipid oxidative damage (TBARs) and nitrite concentration were higher only in the Wistar-ORX than in the Wistar-SHAM group. In the Wistar-ORX and SHR-ORX, the salivary calcium, phosphate, and chloride were increased while no change was detected in the SHAM groups. Only salivary buffering capacity, calcium, and chloride in the SHR-ORX adjusted to values similar to Wistar-SHAM group.

CONCLUSION

Hypertensive phenotype mitigated the orchiectomy-induced salivary dysfunction, since the disturbances were restricted to alterations in the salivary biochemical composition and redox state.

Tolerance to intraoral biofilms and their effectiveness in improving mouth dryness and modifying oral microbiota in patients with primary Sjögren's syndrome: "Predelfi study"

INTRODUCTION

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by exocrine gland dysfunction. No therapeutic strategy is sufficient on its own for the management of dry mouth and therapeutic innovations are required.

METHODS

This Predelfi study was a single-center, prospective, comparative, randomized, double-blind, cross-over controlled study with the primary objective of assessing the tolerance to and effectiveness of two adhesive biofilms (containing prebiotics and, sodium alginate, respectively) in patients with pSS and hyposialia (#NCT04206826 in ClinicalTrials.gov). Secondary objectives were to obtain initial data regarding the clinical effectiveness of such biofilms in the improvement of signs and symptoms related to dry mouth and potential changes in the oral microbiota. Ten pSS patients with pSS were included (9 females and 1 male) with a mean age of 58.1 ± 14.0 years.

RESULTS AND DISCUSSION

Tolerance to the prebiotic and sodium alginate biofilms was assessed by the patients (visual analog scale [VAS] score 66.7 and 87.6, respectively) and the practitioner (90 and 100, respectively). The absolute changes in the VAS scores at the start and end of each treatment period highlighted an improvement in mouth dryness for the sodium alginate versus the prebiotic biofilm. The VAS scores for other parameters (mouth burning sensation; taste alteration; chewing; swallowing and speech difficulties) remained globally comparable between the two groups. Unstimulated salivary flow showed no changes regardless of the biofilm used. Regarding the oral microbiota, the sodium alginate biofilm increased the abundance of the Treponema genus, whereas the use of the prebiotic biofilm as the first treatment increased the abundance of the genera Veillonella and Prevotella. Nevertheless, the prebiotic biofilm appeared to stimulate "milder" genera with regard to periodontal infections. Furthermore, pre-treatment with the prebiotic biofilm prevented the emergence of the Treponema genus induced by subsequent treatment with the sodium alginate biofilm, suggesting a potential protective effect.

Hydrogels for Salivary Gland Tissue Engineering

Mimicking the complex architecture of salivary glands (SGs) outside their native niche is challenging due their multicellular and highly branched organization. However, significant progress has been made to recapitulate the gland structure and function using several in vitro and ex vivo models. Hydrogels are polymers with the potential to retain a large volume of water inside their three-dimensional structure, thus simulating extracellular matrix properties that are essential for the cell and tissue integrity. Hydrogel-based culture of SG cells has seen a tremendous success in terms of developing platforms for cell expansion, building an artificial gland, and for use in transplantation to rescue loss of SG function. Both natural and synthetic hydrogels have been used widely in SG tissue engineering applications owing to their properties that support the proliferation, reorganization, and polarization of SG epithelial cells. While recent improvements in hydrogel properties are essential to establish more sophisticated models, the emphasis should still be made towards supporting factors such as mechanotransduction and associated signaling cues. In this concise review, we discuss considerations of an ideal hydrogel-based biomaterial for SG engineering and their associated signaling pathways. We also discuss the current advances made in natural and synthetic hydrogels for SG tissue engineering applications.

Effects of orchiectomy and testosterone replacement therapy on redox balance and salivary gland function in Wistar rats

The objective of this study was to investigate the effects of orchiectomy (ORX) and testosterone replacement therapy (TRT) on redox balance and function of salivary glands. Forty-five young adult male Wistar rats (3 months old) were either castrated bilaterally or underwent fictitious surgery (SHAM) and were subsequently distributed into 3 groups: SHAM, ORX, and TRT (castrated rats that received an intramuscular injection of testosterone cypionate 10 mg/kg/weekly). All treatments started 4 weeks after castration (4 months old) and lasted 4 weeks (5 months old). At the end of treatment, pilocarpine-induced salivary secretion was collected to analyze salivary flow rate and biochemistry composition, and the parotid (PG) and submandibular (SMG) glands were sampled for redox balance markers and histomorphometric analyses. ORX increased salivary flow rate, calcium, phosphate, and chloride, and decreased total protein and amylase, while not changing the salivary buffer capacity, pH, sodium, and potassium compared to SHAM. TRT restored all salivary parameters to SHAM values. ORX increased oxidative lipid and protein damage, total antioxidant capacity, and uric acid in both salivary glands compared to SHAM. Superoxide dismutase, catalase, and glutathione peroxidase activities were greater only in the SMG of the ORX group in relation to SHAM. ORX decreased duct and acini area, while increasing connective tissue in the PG. On the other hand, ORX reduced duct area and increased acini area in the SMG compared to SHAM. TRT restored the redox balance and histomorphometric parameters to close to SHAM values in both salivary glands. Orchiectomy-induced salivary gland dysfunction was characterized by an increase in the salivary flow rate and changes in the secretion of total protein, amylase, and electrolytes, which are key factors, considered important for maintaining oral health status. To sum up, orchiectomy impaired the redox balance of the salivary glands. Our results also showed that TRT reversed the oxidative damage, morphological alterations, and salivary gland dysfunction induced by orchiectomy. Therefore, these results suggest an important action of testosterone on the redox balance and secretory ability of salivary glands.

Transcriptomic Mapping of Human Parotid Gland at Single-Cell Resolution

As the largest salivary gland in oral cavity, the parotid gland plays an important role in initial digesting and lubricating food. The abnormal secretory function of the parotid gland can lead to dental caries and oral mucosal inflammation. In recent years, single-cell RNA sequencing (scRNA-seq) has been used to explore the heterogeneity and diversity of cells in various organs and tissues. However, the transcription profile of the human parotid gland at single-cell resolution has not been reported yet. In this study, we constructed the cell atlas of human parotid gland using the 10× Genomics platform. Characteristic gene analysis identified the biological functions of serous acinar cell populations in secreting digestive enzymes and antibacterial proteins. We revealed the specificity and similarity of the parotid gland compared to other digestive glands through comparative analyses of other published scRNA-seq data sets. We also identified the cell-specific expression of hub genes for Sjögren syndrome in the human parotid gland by integrating the results of genome-wide association studies and bulk RNA-seq, which highlighted the importance of immune cell dysfunction in parotid Sjögren syndrome pathogenesis.

The effect of eating on the uptake of PSMA ligands in the salivary glands

Rationale

PSMA-directed therapy for metastatic prostate cancer is gaining adoption as a treatment option. However, accumulation of ¹⁷⁷Lu/²²⁵Ac-PSMA in the salivary glands remains a problem, with risk of dose-limiting xerostomia and potentially severe effect on the quality of life. Gustatory stimulation is an approach that has commonly been used in radioactive iodine therapy to reduce accumulation in the salivary glands. However, based on theoretical differences in biodistribution, it was hypothesized that this could potentially lead to adverse increased toxicity for PSMA-ligand therapy. The primary objective of this work was to determine if gustatory stimulation by eating an assortment of sweet/fatty/acidic foods during the biodistribution phase of [¹⁸F]DCFPyl could result in a clinically relevant (> 30%) change in the uptake of the tracer in the salivary glands.

Methods

10 patients who already received a whole-body [¹⁸F]DCFPyl PET/CT scan for evaluation of prostate cancer, underwent a repeat (intervention) PET/CT scan within a month of the first (control) scan. During the intervention scan, patients chose from an assortment of sweet/fatty/acidic foods, which they then chewed and swallowed for a period of time starting 1 min before tracer administration to 10 min thereafter. Data from both scans were analyzed by placing VOIs on the major salivary glands and segmenting them using relative thresholds.

Results

A slight increase in PSMA uptake in the parotid glands was observed on the intervention scan when compared to the baseline scan (+ 7.1% SUL_mean and + 9.2% SUL_max, p < 0.05). No significant difference in PSMA uptake in the submandibular glands was seen.

Conclusions

Eating only slightly increases uptake of [¹⁸F]DCFPyl in the parotid glands. We nonetheless recommend refraining from gustatory stimulation during the administration and early biodistribution phase of radionuclide therapy with PSMA-ligands to reduce the risk of avoidable additional toxicity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13550-021-00838-y.

Salivary flow rate and the risk of cognitive impairment among Korean elders: a cross-sectional study

Background

Salivary function has been suggested to be associated with cognitive impairment. However, the effect of salivary flow rate (SFR) on cognitive impairment remains unclear. This study aimed to investigate whether SFR is associated with cognitive impairment among Korean elders.

Methods

This cross-sectional study included 649 elders aged 65 and older in the Korean community-dwelling population. Cognitive impairment was assessed using the Mini-Mental Status Examination. Unstimulated SFR was measured and dichotomized. Denture status, age, sex, education level, smoking, drinking, diabetes, hypertension, and obesity were considered confounders. Multivariable logistic regression analysis was applied to assess the adjusted association. Stratified analysis by sex and denture status was performed to clarify the effect modification.

Results

Participants without cognitive impairment showed a higher SFR level than those with cognitive impairment (0.81 mL/min for non-cognitive impairment versus 0.52 mL/min for cognitive impairment, p < 0.001). After controlling for confounders, participants with low SFR (< 0.3 mL/min) were more likely to have cognitive impairment by 1.5 times than participants with normal SFR (odds ratio [OR] = 1.5, confidence interval [CI] = 1.05–2.10). The association of low SFR with cognitive impairment was higher in women and dentate participants: about 10% higher in women (OR = 1.63, CI = 1.07–2.50) and about 22% higher in dentate participants (OR = 1.82, CI = 1.41–2.90).

Conclusions

Salivary flow rate is independently associated with cognitive impairment among Korean elders. The association was modified in females and dentate elders. Physicians and dentists should consider low SFR and cognitive impairment as a risk factor between them in clinics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02200-2.

Xerostomia aggravates ligation-induced peri-implantitis: A preclinical in vivo study

OBJECTIVES

Previous studies have indicated that xerostomia is a critical factor affecting periodontitis; nonetheless, it is controversial whether xerostomia impairs peri-implant tissue. The objective of this experimental study was to evaluate the effect of xerostomia on the peri-implant hard and soft tissues in the rat model.

MATERIALS AND METHODS

Implants were placed in bilateral maxillae of male Wistar rats. The animals underwent submandibular and sublingual gland resection on both sides (DRY group) or sham operation (CTR group). Silk ligatures were placed around one side of abutments, which were randomly selected in each animal. The effects of xerostomia were assessed using micro-CT, histological analysis, real-time PCR, and 16S rRNA-based metagenomic analysis.

RESULTS

Ligation with silk thread caused bone resorption around implants. Although xerostomia itself did not induce bone resorption, it significantly enhanced silk ligature-mediated bone resorption around implants. Histological analysis and real-time PCR indicated that xerostomia induced inflammation and osteoclastogenesis around implants with silk ligatures. Furthermore, it altered the microbiota of the plaque on the silk thread around implants.

CONCLUSION

Xerostomia accelerates mucosal inflammation and osteoclastogenesis, which aggravates bone resorption around implants.

Flavor Chemistry of Virgin Olive Oil: An Overview

Virgin olive oil (VOO) has unique chemical characteristics among all other vegetable oils which are of paramount importance for human health. VOO constituents are also responsible of its peculiar flavor, a complex sensation due to a combination of aroma, taste, texture, and mouthfeel or trigeminal sensations. VOO flavor depends primarily on the concentration and nature of volatile and phenolic compounds present in olive oil which can change dramatically depending on agronomical and technological factors. Another aspect that can change the flavor perception is linked to the oral process during olive oil tasting. In fact, in this case, some human physiological and matrix effects modulate the flavor release in the mouth. The present review aims to give an overview on VOO flavor, with particular emphasis on the mechanisms affecting its production and release during a tasting.

Interaction of a Procyanidin Mixture with Human Saliva and the Variations of Salivary Protein Profiles over a 1-Year Period

Procyanidins are widely associated with astringency perception and promptly interact/precipitate salivary proteins (SPs). In this work, the SP profile of 17 volunteers was monitored for 1 year, focusing on the SP families most related to astringency [aPRPs (acidic proline-rich proteins), bPRPs (basic proline-rich proteins), gPRPs (glycosylated proline-rich proteins), cystatins, P-B peptide, and statherin]. Although the total SP content remained constant, bPRPs showed high variability. Saliva from 5 volunteers was selected, each individual's saliva presenting a prominence in one of the referred SP families; each was used to interact with grape seed procyanidin oligomeric fraction. Independent of the prominences, a total depletion in statherin and P-B peptide was observed. These subjects performed a sensory assay and the limit of detection for astringency was determined. Overall, the specificity of SP toward procyanidins seemed to be more important in the interactions than the total SP content. The highest reactivity toward SPs was observed for epicatechin gallate, procyanidin dimers B7, B2g, and trimer C1.

Sialorrhea in Parkinson's Disease

Sialorrhea, or excessive saliva beyond the margin of the lip, is a common problem in many neurological diseases. Previously, sialorrhea has been underrecognized in Parkinson’s disease (PD) patients. Despite this, many patients rank sialorrhea as one of the most debilitating complaints of Parkinson’s disease. Previous treatment for sialorrhea has been suboptimal and has been plagued by significant side effects that are bothersome and can be dangerous in patients with a concurrent neurodegenerative disease. This review sought to review the anatomy, function, and etiology of sialorrhea in PD. It then sought to examine the evidence for the different treatments of sialorrhea in PD, and further examined newer evidence for safety and efficacy in minimally invasive treatment such as botulinum toxin.

Salivary and Serum Inflammatory Profiles Reflect Different Aspects of Inflammatory Bowel Disease Activity

BACKGROUND

Inflammatory bowel disease (IBD) can manifest both macroscopically and microscopically in the oral cavity; however, little is known about salivary changes in IBD. Therefore, this study aimed to assess salivary and circulatory inflammatory profiles in IBD and to compare their potential to reflect the presence and activity of IBD.

METHODS

We measured 92 known inflammatory proteins in serum and in unstimulated and stimulated whole saliva samples from patients with IBD with active intestinal inflammation (n = 21) and matched control patients (n = 22) by proximity extension assay. Fifteen of the patients with IBD returned 10 to 12 weeks after treatment escalation for resampling.

RESULTS

Sixty-seven of the proteins were detected in all 3 sample fluids but formed distinct clusters in serum and saliva. Twenty-one inflammatory proteins were significantly increased and 4 were significantly decreased in the serum of patients with IBD compared with that of the control patients. Two of the increased serum proteins, IL-6 and MMP-10, were also significantly increased in stimulated saliva of patients with IBD and correlated positively to their expressions in serum. None of the investigated proteins in serum or saliva were significantly altered by IBD treatment at follow-up. Overall, inflammatory proteins in serum correlated to biochemical status, and salivary proteins correlated positively to clinical parameters reflecting disease activity.

CONCLUSIONS

Saliva and serum inflammatory profiles in IBD share a similar composition but reflect different aspects of disease activity. The oral cavity reflects IBD through elevated IL-6 and MMP-10 in stimulated saliva.

Role of natural salivary defenses in the maintenance of healthy oral microbiota in children and adolescents

Aim

The present study served the purpose of assessing the levels of salivary immunoglobulin A (IgA), immunoglobulin G (IgG), proteins, calcium, inorganic phosphorus, and alkaline phosphatase levels in caries-free and caries active children.

Materials and Methods

Stratified randomized sampling method was used to include 40 subjects in the age group 12-15 years having a full complement of permanent dentition except for third molars. The selected pediatric subjects were further divided into two groups of 20 each based on DMFS score, Group-I - Caries free (DMFS score = 0) and Group-II - Caries active (DMFS score ≥10). Unstimulated midmorning saliva samples were collected and analyzed colorimetrically and by radial immunodiffusion method for constituents of saliva understudy.

Results

The mean salivary IgA levels in children in Group-I (caries-free children) was 10.63 ± 2.85 mg/dL which was statistically higher as compared to caries active children in Group-II (8.50 ± 1.43 mg/dL).The mean salivary protein level in children of Group-II was statistically higher at 3.28 ± 0.12 mg/dL as compared to Group-I (2.89 ± 0.11 mg/dL).

Conclusion

The present study showed decreased levels of salivary immunoglobulin A and high concentration of salivary protein in children with increased caries experience which is indicative of the protective role of salivary constituents in caries-free children.

Potentiometric Solid-Contact Ion-Selective Electrode for Determination of Thiocyanate in Human Saliva

A new solid-contact potentiometric ion-selective electrode for the determination of SCN- (SCN-ISE) has been described. Synthesized phosphonium derivative of calix[4]arene was used as a charged ionophore. The research included selection of the ion-selective membrane composition, determination of the ISEs metrological parameters and SCN-ISE application for thiocyanate determination in human saliva. Preparation of the ISEs included selection of a plasticizer for the ion-selective membrane composition and type of the electrode material. The study was carried out using ISE with liquid internal electrolyte (LE-ISE) and solid-contact electrodes made of glassy carbon (GC-ISE) and gold rods (Au-ISE). The best parameters were found for GC sensors for which the ion-selective membrane contained chloroparaffin as a plasticizer (S = 59.9 mV/dec, LOD = 1.6 ´ 10-6 M). The study of potentiometric selectivity coefficients has shown that the thiocyanate-selective sensor could be applied in biomedical research for determination of SCN- concentration in human saliva. The accuracy of the SCN- determination was verified by testing 59 samples of volunteers' saliva by potentiometric sensors and UV-Vis spectrophotometry as a reference technique. Moreover, SCN- concentrations in the smokers' and non-smokers' saliva were compared. In order to investigate the influence of various factors (sex, health status, taken medications) on the thiocyanate level in the saliva, more extensive studies on a group of 100 volunteers were carried out. Additionally, for a group of 18 volunteers, individual profiles of SCN- concentration in saliva measured on a daily basis for over a month were collected.

Salivary Biomarkers for Alzheimer's Disease and Related Disorders

The search for accessible and cost-effective biomarkers to complement current cerebrospinal fluid (CSF) and imaging biomarkers in the accurate detection of Alzheimer disease (AD) and other common neurodegenerative disorders remains a challenging task. The advances in ultra-sensitive detection methods has highlighted blood biomarkers (e.g. amyloid-β and neurofilament light) as a valuable and realistic tool in a diagnostic or screening process. Saliva, however, is also a rich source of potential biomarkers for disease detection and offers several practical advantages over biofluids that are currently examined for neurodegenerative disorders. However, while this may be true for the general population, challenges in collecting saliva from an elderly population should be seriously considered. In this review, we begin by discussing how saliva is produced and how age-related conditions can modify saliva production and composition. We then focus on the data available which support the concept of salivary amyloid-β, tau species and novel biomarkers in detecting AD and alpha-synuclein (α-syn) in Parkinson's disease (PD).

Strategies for Developing Functional Secretory Epithelia from Porcine Salivary Gland Explant Outgrowth Culture Models

Research efforts have been made to develop human salivary gland (SG) secretory epithelia for transplantation in patients with SG hypofunction and dry mouth (xerostomia). However, the limited availability of human biopsies hinders the generation of sufficient cell numbers for epithelia formation and regeneration. Porcine SG have several similarities to their human counterparts, hence could replace human cells in SG modelling studies in vitro. Our study aims to establish porcine SG explant outgrowth models to generate functional secretory epithelia for regeneration purposes to rescue hyposalivation. Cells were isolated and expanded from porcine submandibular and parotid gland explants. Flow cytometry, immunocytochemistry, and gene arrays were performed to assess proliferation, standard mesenchymal stem cell, and putative SG epithelial stem/progenitor cell markers. Epithelial differentiation was induced and different SG-specific markers investigated. Functional assays upon neurostimulation determined α-amylase activity, trans-epithelial electrical resistance, and calcium influx. Primary cells exhibited SG epithelial progenitors and proliferation markers. After differentiation, SG markers were abundantly expressed resembling epithelial lineages (E-cadherin, Krt5, Krt14), and myoepithelial (α-smooth muscle actin) and neuronal (β3-tubulin, Chrm3) compartments. Differentiated cells from submandibular gland explant models displayed significantly greater proliferation, number of epithelial progenitors, amylase activity, and epithelial barrier function when compared to parotid gland models. Intracellular calcium was mobilized upon cholinergic and adrenergic neurostimulation. In summary, this study highlights new strategies to develop secretory epithelia from porcine SG explants, suitable for future proof-of-concept SG regeneration studies, as well as for testing novel muscarinic agonists and other biomolecules for dry mouth.

The effect of environment (Dry and Natural Saliva) on clasp retention: In vitro study - Part I

Objective:

The purpose of this study was to investigate the importance of environments (dry and wet) to dislodge the clasp.

Materials and Methods:

Mandibular test models with natural premolar and molar teeth were used to test four types of clasp (each 12) (Akers, rest plate Akers [RPA], half and half [H-H], and ring clasp) in dry and natural fresh saliva environments. Each clasp was pulled out 10 times with a crosshead speed of 10 mm/min and the force required to withdraw each was measured.

Statistical Analysis Used:

A paired sample t-test and Wilcoxon test were used.

Results:

There were significant differences between the dry and wet (natural fresh saliva) environment. However, while the mean of the environment for RPA and ring clasp type was significantly different, the H-H and Akers clasp type was not.

Conclusion:

The environment has an effect on dislodging the clasp but differs according to the type of clasp.

Incorporation of Dosimetric Gradients and Parotid Gland Migration Into Xerostomia Prediction

Purpose: Due to the sharp gradients of intensity-modulated radiotherapy (IMRT) dose distributions, treatment uncertainties may induce substantial deviations from the planned dose during irradiation. Here, we investigate if the planned mean dose to parotid glands in combination with the dose gradient and information about anatomical changes during the treatment improves xerostomia prediction in head and neck cancer patients.

Materials and methods: Eighty eight patients were retrospectively analyzed. Three features of the contralateral parotid gland were studied in terms of their association with the outcome, i.e., grade ≥ 2 (G2) xerostomia between 6 months and 2 years after radiotherapy (RT): planned mean dose (MD), average lateral dose gradient (GRADX), and parotid gland migration toward medial (PGM). PGM was estimated using daily megavoltage computed tomography (MVCT) images. Three logistic regression models where analyzed: based on (1) MD only, (2) MD and GRADX, and (3) MD, GRADX, and PGM. Additionally, the cohort was stratified based on the median value of GRADX, and a univariate analysis was performed to study the association of the MD with the outcome for patients in low- and high-GRADX domains.

Results: The planned MD failed to recognize G2 xerostomia patients (AUC = 0.57). By adding the information of GRADX (second model), the model performance increased to AUC = 0.72. The addition of PGM (third model) led to further improvement in the recognition of the outcome (AUC = 0.79). Remarkably, xerostomia patients in the low-GRADX domain were successfully identified (AUC = 0.88) by the MD alone.

Conclusions: Our results indicate that GRADX and PGM, which together serve as a proxy of dosimetric changes, provide valuable information for xerostomia prediction.

Unsuccessful submandibular duct surgery for anterior drooling: Surgical failure or parotid gland salivation?

OBJECTIVES

To evaluate if drooling recurrence after surgery of the submandibular ducts is due to surgical failure or other variables.

METHODS

Historic cohort with prospective collected data of all patients with severe drooling who underwent unsuccessful submandibular duct surgery with subsequent re-intervention between 2003 and 2018. A reference cohort was used for comparison of clinical variables.

RESULTS

Six males and 4 females were included (cerebral palsy n = 8, neurodevelopmental disorders n = 2). All patients underwent submandibular gland surgery as a primary intervention (duct ligation n = 8, submandibular duct relocation n = 2) followed by re-intervention (submandibular gland excision n = 7, parotid duct ligation n = 3). One patient underwent tertiary surgery (parotid duct ligation after re-intervention by submandibular gland excision). Three patients were successful after re-intervention. No difference was found between both re-intervention techniques. There was significantly more severe dental malocclusion (50% vs. 21%, P value = 0.047) and severe speech disorders (80% vs. 42%, P value = 0.042) in the current cohort when compared to the reference cohort.

CONCLUSION

Recurrence of drooling surgery is most likely not caused by surgical failure of the primary intervention, because re-intervention (submandibular gland excision) did not lead to more success. Dysarthria and dental malocclusion might negatively influence treatment outcome.

Changes in salivary pH following consumption of different varieties of date fruits

Objective

Consumption of date fruits leads to chemical changes in saliva, including variations in pH values. We conducted this study to assess the effect of the consumption of different types of dates on salivary pH.

Methods

We recruited 15 children (aged 6–15 years) who were instructed to consume one piece of specific types of dates (Safree, Nabtat Seif, Khalas, Sukkari, and Segae) for 5 consecutive days. On the 6th and 7th days, the children consumed a quarter of a grapefruit (positive control) and chewed on a sterilised cotton pellet (negative control), respectively. Salivary samples from unstimulated kids were collected at least 1 h after breakfast every day and the salivary pH was recorded.

Results

When compared with the pH values before date consumption, the lowest mean salivary pH value among the date-consuming groups 5 min after salivary stimulation was noted after the consumption of Khalas (6.26), followed by those after consumption of Safree (6.31), Nabtat Seif (6.36), Segae (6.44), and Sukkari (6.45). The highest difference in mean values was observed for Khalas (.47), followed by those for Sukkari (.45), Nabtat Saif (.44), Segae (.38), and Safree (.35). The pH of saliva collected after grapefruit consumption was the lowest, whereas chewing cotton pellets led to an increased salivary pH.

Conclusion

This study showed a decrease in the salivary pH following date consumption, but not to a value as low as the critical value. These findings suggest that dates do not have detrimental effects on salivary parameters.

Analysis of oral health conditions and risk factors for dental caries in patients with sickle cell disease

ABSTRACT Objective: To analyze the oral health conditions and risk factors for caries in patients with sickle cell disease. Methods: An observational, cross-sectional study was conducted in the clinic of the Association of Persons with Hemoglobinopathies of Alagoas, in the city of Maceió-AL, Brazil. The sample composed of 43 patients were included by census sampling. The ICDAS/DMFT/dmf-t caries indices were used, and simplified oral hygiene, salivary flow and buffer capacity tests were performed. Patients were interviewed to check their level of knowledge about oral hygiene and diet. Spearman correlation and ANOVA statistical tests were applied (p<0.05). Results: The mean DMFT was 15.49±4.43; oral hygiene regular (IHOS=2.22±0.18); mean salivary flow 0.92±0.26, and mean buffer capacity 4.60±0.32. Correlation was found between salivary flow and buffer capacity (p = 0.009). Patients with the highest caries prevalence, in the age-ranges 6 to 12, and 20 to 26 years, had the lowest buffer capacity values (p = 0.04). Interviews showed that 58% did not use dental floss, 88% consumed cariogenic snacks, 100% reported never having received guidance from dentists about the cariogenic potential of foods and 60% reported the use of anticholinergic medications to reduce drooling (Tramal® and morphine) during pain crises. Conclusion: These patients presented extremely high caries prevalence, with predominance of carious teeth. The salivary parameters analyzed and level of knowledge about oral hygiene and cariogenic diet presented, showed that patients with sickle cell disease belonged to a group with risk for development of dental caries.

Coupling xylitol with remineralizing agents improves tooth protection against demineralization but reduces antibiofilm effect

To explore the efficiency of xylitol chewing gum enriched or not with remineralizing agents to protect tooth against cariogenic biofilm formation and demineralization. Six groups of chewing gums were prepared; Group 1: isomalt (1.8%), Group 2: casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) (3%) + isomalt (1.8%), Group 3: hydroxyapatite (HAP) (2.5%) + isomalt (1.8%), Group 4: xylitol (1.8%), Group 5: CPP-ACP (3%) + xylitol (1.8%) and Group 6: HAP (2.5%) + xylitol (1.8%). The antibiofilm properties of different chewing gum extracts using seven oral bacterial species including Streptococcus mutans, Streptococcus constellatus, Streptococcus Salivarius and Streptococcus oralis were explored via the crystal violet staining assay. The remineralizing effects of those products were assessed on thirty human permanent teeth, half-protected with varnish before chemical erosion and thermocycling process with chewing gum. Remineralization was evaluated using scanning electron microscopy and microscopic measurements on polarized light microscopy. The ratio R comparing the thickness between unvarnished and varnished sides was evaluated. While the minimum biofilm inhibitory concentration (MBIC₅₀) was low for xylitol alone compared to isomalt, it was inconsistent when enriched with remineralizing agents. The minimum biofilm eradication concentration (MBEC₅₀) was low for xylitol groups compared to isomalt, for all the studied strains. R was significantly lower in Group 1 and Group 2, while Group 6 showed the highest ratio. Xylitol chewing gums confirmed good antibiofilm properties and showed remineralized potential on eroded teeth. When xylitol is associated to CPP-ACP or HAP, antibiofilm activity decreased while remineralization of eroded teeth increased.

Chronic exposure to inorganic mercury induces biochemical and morphological changes in the salivary glands of rats

Mercury exposure is considered to be a public health problem due to the generation of toxic effects on human health as a result of environmental and occupational conditions. The inorganic form of mercury (HgCl₂) can cause several biological changes in cells and tissues through its cumulative toxic potential, but little has been experimentally proven about the effects of inorganic mercury on salivary glands, an important modulator organ of oral health. This study analyzes the effects of prolonged low dose exposure to HgCl₂ on the salivary glands of rats. Adult animals received a dose of 0.375 mg kg^-1 day^-1 over a period of 45 days. The parotid and submandibular glands were collected for analysis of the mercury levels and evaluation of oxidative stress, histological parameters and immunomodulation for metallothionein I and II (MT-I/II). In this investigation, biochemical and tissue changes in the salivary glands were verified due to the mercury levels, causing reduction in antioxidant capacity against peroxyl radicals, with consequent cellular lipid peroxidation and an increase in nitrite levels, volumetric changes and cytoskeletal damage in the submandibular glands, with less severe damage to the parotid glands. The results also have shown the occurrence of a cytoprotection mechanism due to increased MT-I/II expression, but not enough to avoid the morphology and oxidative damage. This evidence highlights, for the first time, that inorganic mercury is able to alter the morphology and oxidative biochemistry in salivary glands when exposed for a long time in low doses.

The Saliva Proteome of Dogs: Variations Within and Between Breeds and Between Species

Saliva is a complex multifunctional fluid that bathes the oral cavity to assist in soft and hard tissue maintenance, lubrication, buffering, defense against microbes, and initiating digestion of foods. It has been extensively characterized in humans but its protein composition in dogs remains poorly characterized, yet saliva composition could explain (patho) physiological differences between individuals, breeds and with humans. This pilot discovery study aimed to characterize canine saliva from two breeds, Labrador retrievers and Beagles, and to compare this with human saliva using quantitative mass spectrometry. The analysis demonstrated considerable inter-individual variation and difference between breeds; however these were small in comparison to the differences between species. Functional mapping suggested roles of detected proteins similar to those found in human saliva with the exception of the initiation of digestion as salivary amylase was lacking or at very low abundance in canine saliva samples. Many potential anti-microbial proteins were detected agreeing with the notion that the oral cavity is under continuous microbial challenge.

Salivary Protein Roles in Oral Health and as Predictors of Caries Risk

This work describes the current state of research on the potential relationship between protein content in human saliva and dental caries, which remains among the most common oral diseases and causes irreversible damage in the oral cavity. An understanding the whole saliva proteome in the oral cavity could serve as a prerequisite to obtaining insight into the etiology of tooth decay at early stages. To date, however, there is no comprehensive evidence showing that salivary proteins could serve as potential indicators for the early diagnosis of the risk factors causing dental caries. Therefore, proteomics indicates the promising direction of future investigations of such factors, including diagnosis and thus prevention in dental therapy.

Salivary gland hypofunction in KK-Ay type 2 diabetic mice

BACKGROUND

Hypofunction of different organs in the body is associated with diabetes, including in the oral cavity. Diabetes is often associated with xerostomia, but the underlying mechanism is not well characterized. Thus, the mechanisms underlying diabetes-induced xerostomia were investigated in this study in KK-A ^y mice as an experimental model of type 2 diabetes.

METHODS

The mechanisms involved in diabetes-induced xerostomia were investigated using the ex vivo glandular perfusion technique, histological analysis, and immunohistochemical and intracellular signaling analyses.

RESULTS

Ex vivo submandibular gland secretions from KK-A^y mice decreased by 30% following stimulation with 0.3 μmol/L carbachol (CCh), a cholinergic agonist. Acinar cell weight was comparable between KK-A^y and control mice, whereas duct cell weight was significantly greater in KK-A^y mice. Concentrations of Na⁺ and Cl^- in the secreted saliva decreased significantly in KK-A^y mice, supporting the finding of increased ductal tissue in KK-A^y mice. Immunohistochemistry revealed no significant differences between KK-A^y and control mice in terms of the expression of Cl^- and water channels, Na⁺ -K⁺ -2Cl^- cotransporters, and membrane proteins critical for fluid secretion. Cellular signaling analysis revealed that the increase in [Ca²⁺ ]_i in response to 0.3 μmol/L CCh was reduced by 30% in KK-A^y mice, although there was no significant difference in the thapsigargin (1.0 μmol/L)-induced increase in store-depleted calcium between KK-A^y and control mice.

CONCLUSIONS

These results demonstrate that submandibular fluid secretion is diminished in KK-A^y mice because of a diminished increase in [Ca²⁺ ]_i . Duct cell weight increased in KK-A^y mice, possibly leading to increased ion reabsorption and thus decreased Na⁺ and Cl^- concentrations in the secreted saliva.

Characterization, mechanistic analysis and improving the properties of denture adhesives

OBJECTIVE

Denture adhesives are widely used to avoid the detachment and sliding of dentures. However, the adhesion properties can be affected by variation in mouth conditions such as the level of salivation. The objective of this study was to understand the effect of environmental conditions on the adhesion properties of a commercially available denture adhesive named as Poligrip^® Free manufactured by GlaxoSmithKline Ltd., UK and to identify the reasons for the observed variation in its adhesion strength.

METHODS

The failure mechanisms of denture adhesive have been assessed through using different physical, mechanical and thermal characterization experiments. All methods were used in different pH, temperatures, and salivation conditions and at the end, a strategy was proposed to overcome the failure of the paste in hyposalivation as well.

RESULTS

In vitro models mimicking the denture gingival interface were designed to evaluate the adhesion properties of the investigated adhesive. Changes in the adhesion strength in response to three major factors related to the oral conditions including level of salivation, pH, and temperature were measured. The results of lap shear, tensile test, and internal interactions suggested a cohesion failure, where the lowest adhesion strength was due to hyposalivation. Fourier transform infrared spectroscopy (FTIR) and rheological analysis confirmed the importance of hydrogen bonds and hydration in the adhesion strength of the paste.

SIGNIFICANCE

The investigated scenarios are widely observed in patient using denture adhesives and the clinical reports have indicated the inconsistency in adhesion strength of the commercial products. After identifying the potential reasons for such behavior, methods such as the addition of tripropylene glycol methyl ether (TPME) to enhance internal hydrogen bonds between the polymers are proposed to improve adhesion in the hyposalivation scenario.

Correlation among ocular surface disease, xerostomia, and nasal symptoms in patients with differentiated thyroid carcinoma subjected to radioiodine therapy: A prospective comparative study

BACKGROUND

Some complications of radioiodine therapy have been reported, but the involvement of the eyes and adnexa is rarely discussed. The purpose of this study was to determine the correlation among ocular surface changes, xerostomia, and changes in the nasal mucosa associated with radioiodine therapy.

METHODS

Patients subjected to radioiodine therapy (group 1) or not subjected (group 2) were prospectively evaluated by examinations of the ocular surface and tear film, saliva production, and nasal endoscopy. Ocular and nasal symptoms and xerostomia were evaluated using questionnaires.

RESULTS

Evaluation of the ocular surface did not indicate significant differences between the groups. Nasal endoscopy revealed higher mucosal pallor in group 1 and worsening of the endoscopic appearance. Worsening of ocular symptoms and nasal symptoms, xerostomia, and a significant decrease in salivary production was also observed in group 1.

CONCLUSION

Subjective worsening of xerostomia, xerophthalmia, nasal symptoms, and changes in the nasal mucosa in group 1 was observed.

Estimation of Salivary Parameters among Autoimmune Thyroiditis Patients

INTRODUCTION

Saliva is a complex secretion that protects and lubricates the oral cavity. Various systemic diseases and their treatment alter the salivary gland function; one such disease is Autoimmune Thyroid Disease (AITD). AITD has been postulated to exert its hormonal influence on the salivary glands, leading to reduced salivary output. There's a paucity of literature, verifying the stated conjunction in human subjects.

AIM

The aim was to investigate the salivary profile in AITD patients and its comparison with controls.

MATERIALS AND METHODS

Descriptive cross-sectional comparative study was conducted using convenience sampling method for screening the presence of thyroid disorders. Two groups comprising of 30 patients in each group diagnosed with autoimmune hypothyroiditis (n=30) and hyperthyroiditis (n=30) respectively and thirty healthy volunteers who were age and sex matched were included as controls. Saliva was collected and evaluated for Unstimulated Salivary Flow Rate (USSFR), pH and buffer capacity. ANOVA and Tukey post-hoc test was performed to find the statistical significance and for pairwise comparison.

RESULTS

Statistically significant difference was observed between autoimmune hypothyroiditis, autoimmune hyperthyroiditis and control group with respect to USSFR (p<0.007), pH (p<0.001) and buffer capacity (p<0.001). On pairwise comparisons statistically significant difference was observed between autoimmune hypothyroiditis and autoimmune hyperthyroiditis with respect to controls.

CONCLUSION

We conclude that significant involvement of salivary glands may occur in cases of AITD. Our study showed significant reduction of sialometric values in AITD patients when compared to controls. A strong clinical suspicion of thyroid diseases should be considered when there is chronic hyposalivation; hence thyroid profile must also be done, if the known causes have been excluded.

Sensorial properties of red wine polyphenols: Astringency and bitterness

Polyphenols have been the subject of numerous research over the past years, being referred as the nutraceuticals of modern life. The healthy properties of these compounds have been associated to a natural chemoprevention of 21st century major diseases such as cancer and neurodegenerative diseases (e.g. Parkinson's and Alzheimer's). This association led to an increased consumption of foodstuffs rich in these compounds such as red wine. Related to the ingestion of polyphenols are the herein revised sensorial properties (astringency and bitterness) which are not still pleasant. This review intends to be an outline both at a sensory as a molecular level of the mechanisms underlying astringency and bitterness of polyphenols. Up-to-date knowledge of this matter is discussed in detail.

Use of Saliva Biomarkers to Monitor Efficacy of Vitamin C in Exercise-Induced Oxidative Stress

Saliva is easily obtainable for medical research and requires little effort or training for collection. Because saliva contains a variety of biological compounds, including vitamin C, malondialdehyde, amylase, and proteomes, it has been successfully used as a biospecimen for the reflection of health status. A popular topic of discussion in medical research is the potential association between oxidative stress and negative outcomes. Systemic biomarkers that represent oxidative stress can be found in saliva. It is unclear, however, if saliva is an accurate biospecimen as is blood and/or plasma. Exercise can induce oxidative stress, resulting in a trend of antioxidant supplementation to combat its assumed detriments. Vitamin C is a popular antioxidant supplement in the realm of sports and exercise. One potential avenue for evaluating exercise induced oxidative stress is through assessment of biomarkers like vitamin C and malondialdehyde in saliva. At present, limited research has been done in this area. The current state of research involving exercise-induced oxidative stress, salivary biomarkers, and vitamin C supplementation is reviewed in this article.

Oral Biofluid Biomarker Research: Current Status and Emerging Frontiers

Salivary diagnostics is a rapidly advancing field that offers clinicians and patients the potential of rapid, noninvasive diagnostics with excellent accuracy. In order for the complete realization of the potential of saliva, however, extensive profiling of constituents must be conducted and diagnostic biomarkers must be thoroughly validated. This article briefly overviews the process of conducting a study of salivary biomarkers in a patient cohort and highlights the studies that have been conducted on different classes of molecules in the saliva. Emerging frontiers in salivary diagnostics research that may significantly advance the field will also be highlighted.

Measurement of saliva flow rate in healthy young humans: influence of collection time and mouthrinse water temperature

The aim of the current study was to determine if unstimulated saliva flow (measured in μl min^-1 ) is affected by different durations of sample collection and by temperatures of mouthrinse water used before sample collection. In randomized order, participants provided 10 samples of unstimulated saliva at time points ranging from 1 to 6 min after rinsing with different temperatures of water (10, 20, and 30°C). Data were analysed by one-way anova with post-hoc tests. Test-retest reliability was assessed using Bland-Altman plots and correlation coefficients. A larger volume of saliva was obtained over a longer collection time. No significant difference in saliva flow rate was observed between collection times [mean: 364 (95% CI: 332-397) μl min^-1 ]. Although rinsing with different temperatures of mouthrinse water resulted in no significant difference in saliva flow rates as a result of the mouthrinse water temperatures, 60% of the participants had a higher saliva flow rate after rinsing with mouthrinse water at a temperature of 10°C compared with mouthrinse water at 20 and 30°C, suggesting large individual variation (range: 24-420 μl min^-1 ). These findings provide justification for using saliva collection times of 1-6 min during sampling of unstimulated saliva. The large individual variations in saliva flow rate in response to different mouthrinse water temperatures suggest that standardization, control, and reporting of mouthrinse water temperature is warranted.

Acidogenic Potential of Plain Milk, Milk with Sugar, Milk with Cornflakes and Milk Cornflakes with Sugar: A Comparative Study

Aim

To compare the acidogenic potential of plain milk, milk with sugar, milk with cornflakes, and milk cornflakes with sugar by assessing the salivary pH.

Materials and methods

The study was carried out on 40 school children of 8 to 12 years; 20 boys and 20 girls were randomly selected. The salivary pH was assessed before and after the consumption of milk; milk and sugar; milk and cornflakes; and milk, sugar, and cornflakes. Baseline unstimulated saliva was collected in sterile plastic tube and the pH was recorded. The change in the salivary pH from the respective groups after consuming the test meal was recorded as follows: (1) after 5 minutes; (2) after 10 minutes; (3) after 15 minutes; (4) after 30 minutes; (5) 120 minutes. Statistical analysis was done using Statistical Package for the Social Sciences 18.0 (SPSS).

Results

The average baseline salivary pH among all the groups was 7.26. A fall in pH at 5 minutes was seen in all the four groups. However, at different time intervals 5, 10, 15, 30, and 120 minutes, the pH values between the groups showed a significant difference at p < 00.7, 0.005, 0.001, 0.010, and 0.028 respectively.

Conclusion

The fall in pH in all the groups was not significant to a limit of critical pH. Milk when added with sugar and/or cornflakes as a meal did not pose a threat as there was not significant decrease in pH.

How to cite this article

Bhat SS, Hegde SK, Bhat VS, Ramya KM, Jodalli PS. Acidogenic Potential of Plain Milk, Milk with Sugar, Milk with Cornflakes, and Milk Cornflakes with Sugar: A Comparative Study. Int J Clin Pediatr Dent 2016;9(3):218-221.

Oral pH in gastroesophageal reflux disease

AIMS AND OBJECTIVES

The aim of this study is to compare surface pH in various parts of the oral cavity between patients with gastroesophageal reflux disease (GERD) and healthy controls.

METHODS

Using a flat pH meter sensor, fixed electrode pen type digital pH meter, oral pH levels were assessed at different mucosal sites among 34 GERD patients and 32 healthy controls. Salivary flow rates and buffering capacity were also assessed in them. A thorough oral examination was performed to screen for any oral and dental changes.

RESULT

A significantly lower pH of 6.65 ± 0.13 (mean ± SD) was found in the GERD group compared to control group 7.23 ± 0.12 (p < 0.05). Least pH was found in the floor of the mouth 6.594 ± 0.17 and highest in the lower labial mucosa among the GERD patients. Salivary flow rate and buffering capacity were low in these patients. Significant changes were noticed in the hard and soft tissues of the oral cavity among the GERD group.

CONCLUSION

Oral mucosal pH is altered in GERD patients and may contribute to effects on the oral cavity.

Salivary markers of kidney function - Potentials and limitations

Saliva can be collected non-invasively, repeatedly and without trained personnel. It is a promising diagnostic body fluid with clinical use in endocrinology and dentistry. For decades, it is known that saliva contains also urea, creatinine and other markers of renal function. Clinical studies have shown that the salivary concentrations of these markers could be useful for the assessment of kidney function without the need of blood collection. This article summarizes the clinical and experimental data on the use of saliva as a diagnostic fluid in nephrology and points out the advantages, pitfalls, technical requirements and future perspective for the use of saliva as a novel potential diagnostic biofluid.