Dental care professionals' awareness of oral dryness and its clinical management: a questionnaire-based study.

BACKGROUND: Despite the high prevalence of oral dryness and awareness of its complications, there is limited research on the clinical management of patients with oral dryness in general dental care. PURPOSE: To (1) describe and compare awareness among dental care professionals regarding saliva functions, potential causes and complications of oral dryness, and patient management (2) Investigate if the length of professional experience influences these aspects. METHODS: A digital self-administrated survey was sent to 2668 dental care professionals working in the general dental care, Public Dental Service, in Sweden. Twelve dental care professionals reviewed the questionnaire prior to its distribution. The questionnaire comprised 32 questions about patient management, awareness of saliva functions, causes and complications of oral dryness, and self-assessment queries. RESULTS: The response rate was 18.6% (241 dentists and 257 dental hygienists). Older adults (65+) were asked more often about dry mouth (93.0%) compared to those aged 18-23 years (50.0%) and those under 18 years (24.9%). Dental hygienists encountered individuals with oral dryness more frequently (61.1%) than dentists (48.5%) (p < 0.01), and more often asked individuals in the age groups 18-23 years (p = 0.003), 24-40 years (p = 0.045), and 41-65 years (p = 0.031) about dry mouth. A higher proportion of dental hygienists (88.3%) than dentists (51.0%) had measured salivary secretion rate, (p < 0.001) and more often suggested preventive dental care 3-4 times a year, (42.5% vs. 30.5%) (p < 0.007). Dentists had a higher awareness of saliva functions, while dental hygienists had a higher awareness about causes and complications of oral dryness. Higher proportions of dentists and dental hygienists with over 10 years of professional experience had measured salivary secretion rate (69.1% vs. 95.7%) compared to their counterparts with less than 10 years of professional experience (35.9% vs. 79.5%) (p < 0.001 for both). CONCLUSION: Compared to dentists, dental hygienists were more attentive to patients with oral dryness as they encountered these individuals more often, asked more age-groups, suggested frequent preventive measures, and had higher awareness of the causes and complications of oral dryness. Length of professional experience could improve both the management of patients with oral dryness and awareness of its causes, particularly for dental hygienists.

Salivary Electrostimulation in the Treatment of Radiation Therapy-Induced Xerostomia (LEONIDAS-2): A Multicenter, Randomized, Double-Masked, Sham-Controlled, Phase 3 Trial.

PURPOSE: Radiation therapy-induced xerostomia significantly affects quality of life in head and neck cancer survivors. Neuro-electrostimulation of the salivary glands may safely increase natural salivation and reduce dry mouth symptoms. METHODS AND MATERIALS: This multicenter, double-masked, randomized, sham-controlled clinical trial assessed the long-term effects of a commercially available intraoral neuro-electrostimulating device in lessening xerostomia symptoms, increasing salivary flow, and improving quality of life in individuals with radiation therapy-induced xerostomia. Using a computer-generated randomization list, participants were assigned (1:1) to an active intraoral custom-made removable electrostimulating device or a sham device to be used for 12 months. The primary outcome was the proportion of patients reporting a 30% improvement on the xerostomia visual analog scale at 12 months. A number of secondary and exploratory outcomes were also assessed through validated measurements (sialometry and visual analog scale) and quality-of-life questionnaires (EORTC QLQ-H&N35, OH-QoL16, and SF-36). RESULTS: As per protocol, 86 participants were recruited. Intention-to-treat analyses showed no statistical evidence of a difference between the study groups with respect to the primary outcome or for any of the secondary clinical or quality-of-life outcomes. Exploratory analyses showed a statistically significant difference in the changes over time of the dry mouth subscale score of the EORTC QLQ-H&N35 in favor of the active intervention. CONCLUSIONS: LEONIDAS-2 did not meet the primary and secondary outcomes.

Factors Associated with Hyposalivation in Brazilian Adults

ABSTRACT Objective: To determine the occurrence of hyposalivation in Brazilian adults and its association with individual determinants, such as the use of medications, systemic conditions, smoking, and alcohol consumption. Material and Methods: A cross-sectional study with 402 adults was developed. Information was collected on sociodemographic and general health characteristics, and sialometry was performed with stimulated salivary flow. It indicated low salivary flow when ≤ 0.7 mL/min. Bivariate and multivariate analyses were conducted using a decision tree (p<0.05). Results: The sample was comprised predominantly of women (68.2%) aged ≤ 29 years (25.4%). Most participants did not use medication (56.7%). Among systemic diseases, the most cited was hypertension (25.1%). More than a third of the participants presented hyposalivation (40.3%), being associated with the following variables: age between 50 to 59 years (p=0.011), female sex (p<0.001), menopause (p=0.001), use of alcohol (p=0.033), systemic disease (p=0.002) and medication use (p<0.001). In multivariate analysis, in addition to sex (p<0.001) and hypertension (p=0.005), an association was also found between hyposalivation and diabetes (p=0.014). Conclusion: Factors associated with hyposalivation in adults were sex and the presence of hypertension or diabetes.

Probing behavior of the leafhopper analyzed through DC electropenetrography and microscopy.

Yamatotettix flavovittatus Matsumara is a new leafhopper species vector of sugarcane white leaf (SCWL) phytoplasma that causes sugarcane chlorosis symptoms. The effects of probing behavior of Y. flavovittatus on sugarcane and its implication for SCWL phytoplasma transmission are yet to be studied. In this research, we used DC electropenetrography (EPG) to define waveforms produced by adult and fifth-instar nymphal Y. flavovittatus on sugarcane and correlated them with salivary sheath termini (likely stylet tip locations) via light and scanning electron microscopy. The following six waveforms and associated activities are described: (NP) non-probing, (Yf1) stylet probing into epidermal cells, (Yf2) stylet probing through mesophyll/parenchyma, (Yf3) stylet contact with phloem and likely watery salivation, (Yf4) active ingestion of sap from phloem, probably sieve elements, and (Yf5) unknown stylet activity in multiple cell types. Study findings reveal that the Y. flavovittatus vector ingests sieve tube element more frequently and for longer durations than any other cell type, supporting that Y. flavovittatus is primarily a phloem feeder. Adult Y. flavovittatus show a longer total probing duration and produces a high density of puncture holes on sugarcane leaves. Moreover, probing behaviors revealed that adults typically ingest phloem sap more frequently and for longer durations than fifth-instar nymphs, enhancing sap ingestion. Furthermore, we propose that adults are more likely to acquire (during Yf4) and inoculate (during Yf3) higher amounts of phytoplasma than fifth-instar nymphs. This information on the penetration behavior of leafhopper Y. flavovittatus serves as a basis for advanced studies on the transmission mechanism of SCWL phytoplasma.

The Mechanism of Core Chinese Medicine Combination in Treating Salivation.

OBJECTIVE: To analyze the regularity of modern Chinese herbal compound in the treatment of salivation based on data mining technology, and to study the potential mechanism of core Chinese herbal medicine in the treatment of salivation using network pharmacology and molecular docking. METHODS: CNKI, VIP and Wanfang literature databases were searched.Choose a prescription for salivation.Excel2019 was used to establish a database of formulas for the treatment of salivation.The included TCM compounds were analyzed by frequency statistics and association rules using the ancient and modern medical record cloud platform to obtain the core drug pairs.TCMSP and Uniprot were used to search the components and targets of the core drug pairs, and intersected with the disease targets obtained from Genecards, OMIM, TTD, PharmgKb, and DrugBank platforms.Complex networks were constructed by cytoscape3.9.1; PPI networks were completed by STRING platform; GO and KEEG pathway enrichment analysis was performed by R language; finally molecular docking validation was performed using AutoDockTools software; and the results were visualized by Pymol software. RESULTS: 122 prescriptions were obtained, 194 herbs were used, the total frequency was 1047, and the top ten drugs used were Atractylodes macrocephala Koidz, Poria cocos, Glycyrrhiza uralensis, Yizhiren, Citrus sinensis, Codonopsis pilosula, Yam, Pinellia ternate, Zingiber officinale, and Coptis chinensis.After association rule analysis, the core drug pair Codonopsis pilosula - Atractylodes macrocephala Koidz was obtained.Twenty-seven effective active components of core drug pairs were screened, corresponding to 62 targets for the treatment of salivation, and four core targets were MAPK1, TP53, MAPK14, and ESR1.GO enrichment analysis yielded 1789 biological process entries, 81 cellular component entries and 111 molecular function entries.KEGG enrichment analysis resulted in 157 pathways, and the first 30 were selected for visualization.Molecular docking of luteolin, 7-Methoxy-2-methyl isoflavone, Stigmasterol, 3ß-acetoxyatractylone, Frutinone A, 3betaHydroxymethyllenetanshiquinone, glycitein to the core target showed that the key active components had good binding activity to the core target. CONCLUSION: The key active components of Codonopsis pilosula and Atractylodes macrocephala Koidz in the treatment of salivation act on MAPK1, TP53, MAPK14 and ESR1 through Calcium, PI3K Akt and IL-17 signaling pathways to regulate the physiological processes of nerve, muscle, endocrine and reproductive systems and the physiological functions of nerve cells, providing a theoretical reference for the later study of integrated traditional Chinese and western medicine in the treatment of salivation.

Botulinum toxin in the treatment of sialorrhea in severe neurological patients with tracheotomy.

OBJECTIVE: To observe the clinical effect of botulinum toxin type A (BTA) injection into the salivary glands of the severe neurological patients with tracheotomy METHODS: Seven patients with severe neurological disorders after tracheotomy and obvious drooling symptoms were enrolled. BTA was injected into bilateral parotid glands and submandibular glands under the guidance of ultrasound. Unstimulated salivary flow rate (uSFR) and Drooling Severity and Frequency Scale (DSFS) were used to evaluate drooling before injection, 1 week, and 4 weeks after injection. We compared the extubation time, time of changing from balloon cannula to metal cannula, hospitalization time and incidence of recurrent pulmonary infection between these patients and other patients accepted conventional curation. RESULTS: (1) The drooling severity scale (DSFS-S), the drooling frequency scale (DSFS-F), the drooling frequency and severity scale total score (DSFS-T) were significantly lower at 4 weeks after BTA injection compared to prior-treatment (p < .001). (2) uSFR of 1 week and 4 weeks were both statistically decreased than the untreated condition (p < .001). (3) Compared with the conventional group, the time of changing from balloon cannula to metal cannula was shortened obviously (p < .05) and incidence of recurrent pulmonary infection was clearly decreased (p < .05) after BTA treatment CONCLUSION: Ultrasound-guided BTA injection into salivary glands can effectively reduce saliva secretion. We also found that the time of changing cannula was shortened obviously and the incidence of recurrent pneumonia infection was reduced. BTA injection of salivary glands to cure drooling could advance to the clinical therapy in severe neurological patients after tracheotomy.

An effective salivation-facilitating method for COVID-19 testing: An experimental study.

BACKGROUND: Simple tools, such as antigen test kits, are readily available for determining coronavirus disease 2019 infection at hospitals and homes. However, it is challenging for elderly people who are prone to dry mouth and other diseases. The main objective of this study was to investigate whether the presence or consumption of a plum pickle can facilitate salivation during coronavirus disease 2019 testing. METHOD: Twenty healthy adult women participated in the study. The participants were allocated to 2 groups: presentation and non-presentation (n = 10; with and without presentation of a plum pickle, respectively), and eating and non-eating (n = 10; with and without consumption of plum pickle, respectively). We recorded the number of saliva swallows in 1 minute under each condition, using a swallowing test device, which attached film sensors to the hyoid bone and thyroid cartilage. RESULTS: There was a significant difference in the number of swallows between the non-presentation and presentation groups ( P < .01, r = 0.89, Z = -2.82) as well as between the non-eating and eating groups ( P < .01, r = 0.85, Z = -2.68). CONCLUSIONS: The strength of 3 factors, namely: direct stimulation with citric acid, saliva buffer capacity, and motor learning, may have affected the results. Our study suggests that saliva collection using the plum pickle is an effective complementary method for facilitating salivation. This technique may be useful in avoiding the risk associated with citric acid intake and for efficient specimen collection during coronavirus disease 2019 testing. In the future, we need to verify this method in elderly participants in a clinical setting.

The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a systematic review and meta-analysis.

BACKGROUND: Xerostomia negatively affects quality of life. Symptoms include oral dryness; thirst; difficulty speaking, chewing, and swallowing food; oral discomfort; mouth soft tissue soreness and infections; and rampant tooth decay. The objective of this systematic review and meta-analysis was to investigate if gum chewing is an intervention that results in objective improvements in salivary flow rates and subjective relief from xerostomia. METHOD: We searched electronic databases including Medline, Scopus, Web of Science, Embase, Cochrane Library (CDSR and Central), Google Scholar and the citations of review papers (last searched 31/03/23). The study populations included: 1) elderly people with xerostomia (> 60 years old, any gender, and severity of xerostomia), and 2) medically compromised people with xerostomia. The intervention of interest was gum chewing. Comparisons included gum chewing vs. no gum chewing. The outcomes included salivary flow rate, self-reported xerostomia, and thirst. All settings and study designs were included. We conducted a meta-analysis on studies where measurements of unstimulated whole salivary flow rate for both a gum chewing, and no gum chewing intervention (daily chewing of gum for two weeks or longer) were reported. We assessed risk of bias using Cochrane's RoB 2 and ROBINS-I tools. RESULTS: Nine thousand six hundred and two studies were screened and 0.26% (n = 25) met the inclusion criteria for the systematic review. Two of the 25 papers had a high overall risk of bias. Of the 25 papers selected for the systematic review, six met the criteria to be included in the meta-analysis which confirmed a significant overall effect of gum on saliva flow outcomes compared to control (SMD = 0.44, 95% CI: 0.22-0.66; p = 0.00008; I2 = 46.53%). CONCLUSIONS: Chewing gum can increase unstimulated salivary flow rate in elderly and medically compromised people with xerostomia. Increasing the number of days over which gum is chewed increases the improvement in the rate of salivation. Gum chewing is linked with improvements in self-reported levels of xerostomia (although it is noted that no significant effects were detected in five of the studies reviewed). Future studies should eliminate sources of bias, standardise methods to measure salivary flow rate, and use a common instrument to measure subjective relief from xerostomia. STUDY REGISTRATION: PROSPERO CRD42021254485.

Effects of interferential current electrical stimulation (IFCS) on mastication and swallowing function in healthy young adults: A preliminary study.

OBJECTIVES: This study aimed to investigate the effects of interferential current electrical stimulation (IFCS) on masticatory and swallowing function. MATERIALS AND METHODS: Twenty healthy young adults were enrolled. The measurement items were spontaneous swallowing frequency (SSF), voluntary swallowing frequency (VSF), saliva secretion volume (SSV), glucose elution volume (GEV), and velocity of chew (VOC). All participants underwent both IFCS and sham stimulation (without stimulation, sham). Two sets of independent IFCS electrodes were placed on the bilateral neck. The precise location of the upper electrodes was just below the angle of the mandible, while the lower electrodes were placed at the anterior border of the sternocleidomastoid muscle. The intensity of IFCS was determined to be one level below the perceptual threshold that all participants felt discomfort. Statistical analysis was performed using a two-way repeated measures analysis of variance. RESULTS: For IFCS, the results of each measurement before and during stimulation were SSF: 1.16 and 1.46, VSF: 8.05 and 8.45, SSV: 5.33 and 5.56 g, GEV: 171.75 and 208.60 mg/dL, and VOC: 87.20 and 95.20, respectively. SSF, GEV, and VOC during stimulation were significantly increased by IFCS (SSF, p = .009; GEV, p = .048; and VOC, p = .007). Following sham stimulation, the results were SSF: 1.24 and 1.34, VSF: 7.75 and 7.90, SSV: 5.65 and 6.04 g, GEV: 176.45 and 187.35 mg/dL, and VOC: 91.35 and 88.25, respectively. CONCLUSION: While no significant differences were observed in the sham group, our findings suggest that IFCS of the superior laryngeal nerve may impact not only the swallowing function but also the masticatory function.

Ganoderma lucidum polysaccharides ameliorates D-galactose-induced aging salivary secretion disorders by upregulating the rhythm and aquaporins.

Longer-term deterioration in saliva secretion has been observed to occur in response to aging. The functional deterioration of the salivary gland damages swallowing and chewing abilities and consequently reduces life quality of the elderly. There are, however, only a few proven effective treatments for aging salivary secretion disorders. Ganoderma lucidum polysaccharide (GLP) has been applied to treat various diseases because of its safety, efficacy, and low cost. We investigated the protective effect of GLP on the submandibular gland (SMG) during aging. D-galactose (D-gal) was used to treat the aging mice, and the body weight, water consumption, saliva secretion, and flow rate were measured after 6 weeks of modeling. Micromorphological changes of the SMG were assessed by hematoxylin-eosin staining and transmission electron microscopy. RT-qPCR and Western blot were used to detect the expression of apoptotic proteins and inflammatory cytokines. Aquaporins (AQPs) and rhythmic protein expression were analyzed by immunohistochemistry and immunofluorescence. The results showed that GLP effectively promoted the expression of AQP5, AQP4, and AQP1, inhibited the release of TNF-α, IL-6, and Bax, and reduced inflammation and apoptosis. Further experiments showed that GLP promoted the up-regulation of core clock genes and proteins and restored the co-localized expression of CLOCK and AQP5 that were weakened during aging, helping to attenuate aging-induced weight loss, decreased salivation, and structural and functional damage. The findings of this work contribute to understanding the nature of age-related modifications in SMG by identifying changes in AQP5 expression and regulatory mechanisms linked to SMG dysfunction during aging. GLP is a potential drug for maintaining healthy salivary gland (SG) status and preventing SG deficiency in the elderly.

The effect of botulinum neurotoxin A on soft-tissue complications in intraoral reconstructions.

BACKGROUND: Intraoral reconstruction has become more common in recent years. Patients may suffer from complications because of hypersalivation. This issue can be overcome with an aid aimed at reducing saliva production. In this study, patients who underwent flap reconstruction were examined. The aim was to compare the complication rates between those who were administered with botulinum neurotoxin type A (BTXA) to the salivary glands before the reconstruction and those who were not. METHODS: Patients who underwent flap reconstruction between January 2015 and January 2021 were included in the study. The patients were divided into 2 groups. BTXA was applied to the parotid and submandibular glands in the 1st group at least 8 days before the operation to reduce the salivary secretion. BTXA application was not applied to the patients in the 2nd group before the operation. RESULTS: A total of 35 patients were included in the study. There were 19 patients in group 1 and 16 patients in group 2. The tumor type in both groups was squamous cell carcinoma. For patients in the 1st group, salivary secretion decreased in an average of 3.84 days. In the statistical analysis, no significant difference was found between the groups in terms of age, comorbidity, smoking-complication development, and comorbidity-complication development. When infection was excluded, there was a significant difference in the development of complications between the groups. CONCLUSIONS: BTXA application before the operation is beneficial to minimize complications in patients who plan to undergo elective intraoral reconstruction.

Salivary gland bioengineering - yesterday, today, tomorrow!

Salivary glands are specialized structures developed as an extensively compact, arborized design through classical embryogenesis, accompanied by a cascade of events channelized by numerous growth factors and genetic regulatory pathways. Salivary secretions maintain oral homeostasis and, when diminished in certain conditions, present as xerostomia or salivary hypofunction, adversely impacting the patient's quality of life. The current available treatments primarily aim at tackling the immediate symptoms providing temporary relief to the patient. Despite scientific efforts to develop permanent and effective solutions to restore salivation, a significant permanent treatment is yet to be established. Tissue engineering has proven as a promising remedial tool in several diseases, as well as in xerostomia, and aims to restore partial loss of organ function. Recapitulating the physiological cellular microenvironment to in vitro culture conditions is constantly evolving. Replicating the dynamic multicellular interactions, genetic pathways, and cytomorphogenic forces, as displayed during salivary gland development have experienced considerable barriers. Through this review, we endeavour to provide an outlook on the evolution of in vitro salivary gland research, highlighting the key bioengineering advances and the challenges faced with the current therapeutic strategies for salivary hypofunction, with an insight into our team's scientific contributions.

Alteration of tight junctions during botulinum toxin type A-inhibited salivary secretion.

OBJECTIVES: Tight junctions (TJs) are involved in the regulation of salivary secretion via paracellular pathway. Botulinum toxin type A (BTXA) is widely used for the treatment of hypersecretion diseases such as sialorrhea. This study aimed to investigate the role of TJs in BTXA-inhibited secretion of the submandibular gland (SMG). MATERIALS AND METHODS: BTXA was injected into the SMGs of rats, and the same amount of saline was injected as a control. Western blot, real-time PCR, and immunofluorescence staining were used to detect the expression and distribution of TJ proteins. Paracellular permeability was evaluated using the transepithelial electrical resistance (TER) measurements and fluorescent tracer detection in BTXA-stimulated SMG-C6 cells. RESULTS: BTXA injection into the SMGs of rats led to increased expression of claudin (Cldn) -1 and Cldn3. Immunofluorescence staining showed no significant changes in the distribution of TJ proteins. In vitro, BTXA increased the TER values and significantly reduced the permeability of fluorescent tracer, suggesting that BTXA decreased the paracellular permeability. The expression levels of Cldn1, Cldn3, and Cldn4 were upregulated after BTXA treatment. CONCLUSION: The expression of TJ proteins changed in both animal models and SMG-C6 cells after BTXA treatment, which may contribute to the inhibition of salivary secretion.

Salivation in Parkinson's disease: A scoping review.

OBJECTIVES: We aimed to provide an overview of the available literature that includes both objective assessments (namely hypersalivation and hyposalivation) and the subjective experience (namely xerostomia and drooling) of salivary problems in patients with Parkinson's disease. BACKGROUND: In patients with Parkinson's disease, there may be complaints of salivary problems such as xerostomia or drooling. This can have consequences for their oral health and quality of life. To date, systematic reviews have focused on drooling only. MATERIALS AND METHODS: A literature search in 4 databases was performed up to 12 February 2021. Two researchers independently assessed studies for eligibility. RESULTS: In total, 63 studies were included. The prevalence of self-reported xerostomia ranged from 49% to 77%, and that of self-reported drooling ranged from 5% to 80%. Ten articles reported a significantly lower mean salivary flow in patients with Parkinson's disease than in controls. None of the articles with both a control group and a patient group reported a significantly higher salivary flow in patients with Parkinson's disease. When questioned about subjective salivary problems, a significantly higher prevalence of both xerostomia (7 studies) and drooling (14 studies) was found in patients with Parkinson's disease than in controls. Patients with Parkinson's disease have a lower salivary flow rate and higher prevalence of both xerostomia and drooling than controls. CONCLUSION: The complexity of salivary problems present in patients with Parkinson's disease necessitates a multidisciplinary approach in order to avoid mutually counteracting treatments from different healthcare professionals.

Effect of continuous sweet gustatory stimulation on salivary flow rate over time.

OBJECTIVE: This study aimed to determine changes in saliva secretion and subjective taste intensity during a sustained period with continuous gustatory stimulation. DESIGN: Twenty-two healthy adults participated in this study. The selected taste solutions were aspartame, sucralose, and acesulfame potassium, which are nonnutritive sweeteners. The concentrations of sucralose1 and acesulfame potassium were set to show the same sweetness intensity as aspartame. Sucralose2 was twice the concentration of sucralose1. The solution was continuously fed into the oral cavity at a flow rate of 0.04 mL / min through a neck-worn precise infusion system. The salivary flow rate (g/min) after 10 min of intraoral water supply from the device was used as the baseline. Salivary flow rate, subjective taste intensity evaluated by the visual analog scale (VAS), and salivary flow rate relative to the baseline were recorded at 10, 30, 60, and 120 min after the start of the test. RESULTS: In the aspartame, sucralose1, and sucralose2 groups, the salivary flow rate increased significantly from 10 min to 120 min after the start of the test when compared to the rate at baseline (p < 0.05). The relative salivary flow rate increased and the VAS value decreased significantly over time and were affected by the time factor (p < 0.001, p = 0.013, respectively) but not by the sweetener-group factor and the interaction effects. CONCLUSIONS: Continuous gustatory stimulation may maintain increased salivary production for a sustained period.

Effect of bleaching gels with different thickeners under normal and hyposalivation conditions: in situ study.

BACKGROUND: Bleaching gel thickeners induce important changes in tooth enamel and these changes are reversed by saliva. OBJECTIVE: This in situ study aimed to evaluate the effect of bleaching gels with different thickeners on tooth enamel under normal and hyposalivation conditions. METHODOLOGY: Of 28 participants, 14 had normal salivary flow and 14 had low salivary flow. For each salivary flow, four types of treatment were performed with different thickeners: no bleaching (negative control), bleaching with a commercial 10% carbamide peroxide (CP) gel with carbopol (positive control) and bleaching with experimental 10% CP gels with natrosol and aristoflex. Participants used a palatal appliance containing bovine enamel/dentin specimens for 15 days. From day 2 to day 15, specimens were bleached extraorally. The bleaching gel was applied according to the groups for four hours. When the bleaching gel was removed, the palatal appliance was inserted again in the participants' mouth until the next day for another bleaching application. This procedure was repeated for 14 days and on day 15, surface microhardness (SMH), color (ΔE*ab and ΔE00), surface roughness (Ra), scanning electron microscopy (SEM), and energy-dispersive X-ray spectrometry (EDS) analyses were performed and data were subjected to statistical analysis. RESULTS: Neither salivary flow nor thickeners influenced ΔE*ab and ΔE00 results. Carbopol had the lowest SMH, the highest Ra, and the lowest Ca% among all groups. For normal flow, natrosol and aristoflex had higher SMH. For low flow, aristoflex had higher SMH and natrosol and aristoflex had lower Ra. Aristoflex had higher Ca% and Ca/P and differed from carbopol for normal flow. CONCLUSION: For normal flow, 10% CP gels with natrosol and aristoflex caused fewer surface changes, and for low flow, only the 10% CP gel with aristoflex.

Short-term and bystander effects of radiation on murine submandibular glands.

Many patients treated for head and neck cancers experience salivary gland hypofunction due to radiation damage. Understanding the mechanisms of cellular damage induced by radiation treatment is important in order to design methods of radioprotection. In addition, it is crucial to recognize the indirect effects of irradiation and the systemic responses that may alter saliva secretion. In this study, radiation was delivered to murine submandibular glands (SMGs) bilaterally, using a 137Cs gamma ray irradiator, or unilaterally, using a small-animal radiation research platform (SARRP). Analysis at 3, 24 and 48 h showed dynamic changes in mRNA and protein expression in SMGs irradiated bilaterally. Unilateral irradiation using the SARRP caused similar changes in the irradiated SMGs, as well as significant off-target, bystander effects in the non-irradiated contralateral SMGs.

LIMITED EVIDENCE SUGGESTS THAT END STAGE KIDNEY DISEASE AND HEMODIALYSIS MAY IMPACT SALIVARY FLOW RATE AND COMPOSITION.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Rodrigues RP, Vidigal MT, Vieira WA, Nascimento GG, Sabino-Silva R, Blumenberg C, Siqueira MF, Siqueira WL, Paranhos LR. Salivary changes in chronic kidney disease and in patients undergoing hemodialysis: a systematic review and meta-analysis. Journal of Nephrology. 2022 Mar 2:1-29. SOURCE OF FUNDING: The work has been partially funded by CAPES-Finance Code 001. The authors have also acknowledged The Brazilian National Council for Scientific and Technological Development (CNPq) and Minas Gerais State Agency for Research and Development, Brazil (FAPEMIG) for the support. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data.

Impairment of salivary function in juvenile idiopathic oligoarticular arthritis is a sign of early onset disease.

AIM: Recent evidences of the presence of reduced stimulated salivary flow rate and altered saliva composition in oligoarticular juvenile idiopathic arthritis (o-JIA) suggest a specific damage to the salivary glands. The aim of this cross-sectional study was to investigate whether reduced salivary flow rate could be related to age and gender at disease onset in o-JIA. METHODS: A total of 57 Caucasian patients (41 females and 16 males) aged 5 to 16 years affected by o-JIA were consecutively enrolled in the study. Information on medication intake, dietary and oral hygiene habits were gathered through a standardised questionnaire. All patients underwent oral and sialometry examination. CONCLUSION: Early onset disease would seem to be associated with salivary glands impairment. Regular dental and salivary gland function assessments may be highly recommended in o-JIA patients considering that saliva collection is a non-invasive and inexpensive procedure.

Cannabinoid CB1 receptors regulate salivation.

Saliva serves multiple important functions within the body that we typically take for granted, such as helping prepare food for swallowing and defense against oral pathogens. Dry mouth is a primary symptom of SjÓ§gren's syndrome and is a side effect of many drug treatments. Cannabis users frequently report dry mouth, but the basis for this is still unknown. If the effects occur via the endogenous cannabinoid signaling system, then this may represent a novel mechanism for the regulation of salivation. We examined expression of cannabinoid CB1 receptors in submandibular salivary gland using immunohistochemistry and tested regulation of salivation by THC and cannabinoid-related ligands. We now report that CB1 receptors are expressed in the axons of cholinergic neurons innervating the submandibular gland. No staining is seen in submandibular gland epithelial cells (acinar and ductal), or myoepithelial cells (MECs). Treatment with THC (4 mg/kg, IP) or the cannabinoid receptor agonist CP55940 (0.5 mg/kg) reduced salivation in both male and female mice 1 h after treatment. CBD had no effect on its own but reversed the effect of THC in a concentration-dependent manner. Neither the CB1 receptor antagonist SR141716 (4 mg/kg) nor the CB2-selective agonist JWH133 (4 mg/kg) had an effect on salivation. We also found that fatty acid amide hydrolase (FAAH), the enzyme that metabolizes the endocannabinoid anandamide and related lipids, regulates salivation. Salivation was reduced in FAAH knockout mice as well as mice treated with the FAAH blocker URB597 (4 mg/kg). URB597 had no effect in CB1 knockout mice. FAAH protein is detected intracellularly in acinar but not ductal epithelial cells. In lipidomics experiments, we found that FAAH knockout mice chiefly had elevated levels of acylethanolamines, including anandamide, and reduced levels of acyglycines. Our results are consistent with a model wherein endocannabinoids activate CB1 receptors on cholinergic axons innervating the submandibular gland. THC likely acts by plugging into this system, activating CB1 receptors to reduce salivation, thus offering a mechanism underlying the dry mouth reported by cannabis users.