A preliminary study on the relationship between stimulated saliva and periodontal conditions in community-dwelling elderly people

Application of anti-vascular endothelial growth factor antibody restores the function of saliva secretion in a type 2 diabetes mouse model

OBJECTIVES

Xerostomia, a common complication of type 2 diabetes, leads to an increased risk of caries, dysphagia, and dysgeusia. Although anti-vascular endothelial growth factor (VEGF) antibodies, such as ranibizumab (RBZ), have been used to treat diabetic retinopathy, their effects on the salivary glands are unknown. This study evaluated the effects of RBZ on salivary glands to reduce inflammation and restore salivary function in a mouse model of type 2 diabetes.

METHODS

Male KK-Ay mice with type 2 diabetes (10-12 weeks old) were used. The diabetes mellitus (DM) group received phosphate-buffered saline, while the DM + RBZ group received an intraperitoneal administration of RBZ (100 μg/kg) 24 h before the experiment.

RESULTS

Ex vivo perfusion experiments showed a substantial increase in salivary secretion from the submandibular gland (SMG) in the DM + RBZ group. In addition, the mRNA expression levels of TNF-α and IL-1β were considerably lower in this group. In contrast, those of aquaporin 5 were substantially higher in the DM + RBZ group, as revealed by quantitative reverse transcription PCR. Furthermore, the number of lymphocyte infiltration spots in the SMG was notably lower in the DM + RBZ group. Finally, intracellular Ca2+ signaling in acinar cells was considerably higher in the DM + RBZ group than that in the DM group.

CONCLUSION

Treating a type 2 diabetic mouse model with RBZ restored salivary secretion through its anti-inflammatory effects.

Hispanic adults with type 2 diabetes mellitus using lipid-lowering agents have better periodontal health than non-users

Background

Recent studies suggest that lipid-lowering agents (LLA) may reduce chronic periodontitis, but it is unknown whether this benefit extends to people with type 2 diabetes (T2D).

Objective

We assessed the association between LLA use and periodontitis in Hispanic adults with T2D.

Design

This was a cross-sectional observational study.

Methods

We assessed the association of LLA use and periodontal parameters in 253 Puerto Ricans 40-65 years with T2D who participated in the Lipid-Lowering agents use in Periodontitis and Diabetes Study study. Participants were classified as (a) none- or <1 year, (b) 1-4 years, or (c) >4 years. The primary outcome consists of a tertile percent of sites with probing pocket depth (PPD) ⩾ 4 mm and the secondary outcome includes tertiles of percent sites with clinical attachment loss (CAL) ⩾ 4 mm. Multinomial logistic regression models adjusted for age, gender, smoking status, education, waist circumference, glycosylated hemoglobin A1C (HbA1c), bleeding on probing, examiner, and anti-inflammatory agents were used to estimate the association.

Results

LLA (92.5%, statins) was used by 52% of participants. LLA use 1-4 years was associated with lower odds of PPD ⩾ 4 mm (OR: 0.22, p = 0.005; high versus low tertile) or lower odds of CAL ⩾ 4 mm (OR: 0.33, p = 0.02, middle versus low tertile), compared to those with LLA minimal or no use. This association was lost for participants who used LLA for >4 years. LLA users for >4 years with periodontal disease had elevated HbA1c (OR: 1.36, p = 0.05).

Conclusion

The use of LLA for 1-4 years was associated with lower values of periodontal parameters versus minimal LLA use. This association was not present among people using LLA > 4 years users, but these participants had poorer glycemic control compared to other participants. In this cross-sectional study, the finding that LLA use 1- 4 years is associated with lower values of periodontal parameters of severity in T2D individuals may help clarify some of the controversies regarding the benefit of these medications in this population.

Periodontal Disease, Local and Systemic Inflammation in Puerto Ricans with Type 2 Diabetes Mellitus

Periodontal disease (PD) is prevalent in type 2 diabetic condition (T2DM).

OBJECTIVES

We assessed the associations between serum or gingival crevicular fluid (GCF) endothelial and inflammatory mediators and chronic PD among T2DM Hispanic adults.

METHODS

We enrolled 248 Puerto Rican residents with T2DM aged 40-65 years. The exposures included serum inflammatory mediators (IL-1b, IL-6, IL-10, and TNF-α), endothelial adhesion molecules, RANKL levels, and the GCF content of these analytes from a subset of 158 samples. The outcomes included the percent of sites with a probing pocket depth (PPD) ≥ 4 mm and clinical attachment loss ≥ 4 mm. Adjusted logistic regression models were fit to the categorized outcomes.

RESULTS

Increased serum IL-10 (Adj. OR: 1.10, p = 0.04), sICAM-1 (Adj. OR: 1.01; p = 0.06), and elevated serum IL-1β (Adj. OR: 1.93; p = 0.06) were statistically significant or close to being significantly associated with a percent of sites with PPD ≥ 4 mm. An increase in GCF IL-1α (Adj. OR: 1.16; p < 0.01) and IL-1β (Adj: 2.40; p = 0.02) was associated with periodontal parameters.

CONCLUSIONS

Our findings suggested that oral and systemic endothelial and inflammatory mediators are associated with periodontal clinical parameters among Hispanic adults with T2DM.

Can the salivary urea and stimulated saliva concentration be a marker of periodontal diseases in opioid users? A case-control study

Introduction

& Aim: Microbial plaque is the primary cause of periodontal diseases, and smoking and opioid addiction can accelerate microbial plaque formation and disease progression. Adequate saliva flow and salivary urea concentration are important parameters for a healthy periodontium. In this study, the relationship between Periodontal Diseases and the History of opioid addiction was investigated by measuring the Salivary Urea and Stimulated Saliva Concentration.

Materials & methods

This case-control study was conducted on 240 patients (120 cases and 120 controls) in 2021 referred to addiction treatment centers and the dental clinic in Iran, Birjand. The control and case groups were matched in terms of age. Demographic, base data, and clinical examination results were collected by a checklist. Data were analyzed using SPSS 19 and one-way ANOVA and chi-square tests. P-value <0.05 was considered as the significance level.

Results

Periodontitis severity was significantly higher in the case group than in the control group (P-value = 0/000). Salivary urea concentration significantly increased in both case and control groups with an increase in periodontitis severity (P-value = 0/003 in the case group and P-value = 0/000 in the control group), but there was no significant relationship between the stimulated saliva flow rate and the severity of periodontitis in these two groups (P-value>0.05).

Conclusion

Following the use of opioids, the flow of saliva decreases, and with the exacerbation of the periodontal disease, the concentration of urea in saliva increases. Therefore, it seems that the analysis of saliva parameters, including urea concentration, can be useful for the diagnosis of periodontal disease, and saliva urea concentration is not directly related to opioid use.

Oral Health and Nutritional Intake in Community-Dwelling 90-Year-Old Japanese People: A Cross-Sectional Study

INTRODUCTION

This study aimed to determine the relationship between dentition, mastication, salivation and nutritional intake in 90-year-old Japanese people.

METHODS

This cross-sectional study included 84 participants (39 men and 45 women) aged 90 years. We used questionnaires to collect demographic information, smoking status, nutritional intake and higher-level functional capacity. Nutritional intake was assessed using the validated Brief-Type Self-Administered Diet History Questionnaire, and higher-level functional capacity was assessed using the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) questionnaire. Oral examinations, masticatory performance tests, stimulated salivary flow rate (SSF) tests, blood tests, blood pressure tests and body mass index (BMI) assessments were conducted. Univariable and multivariable linear regression analyses were performed.

RESULTS

Multivariable linear regression analyses adjusted for sex, education, TMIG-IC and BMI ≤20 kg/m² showed that participants with masticatory performance <173 mg/dL had lower intake of folic acid and vitamin A than those with masticatory performance ≥173 mg/dL. SSF was positively associated with intake of vitamin A. The number of teeth was positively associated with the intake of β-carotene. With smaller effect sizes, masticatory performance, SSF and number of teeth were also associated with the intake of various micronutrients and carbohydrates.

CONCLUSION

Lower masticatory performance, lower SSF and fewer teeth were associated with a lower intake of several micronutrients, such as vitamin A, β-carotene and folic acids, in Japanese individuals of advanced age. Oral health practitioners should pay careful attention to the nutritional intake of older people with poor mastication, dry mouth and severe tooth loss.

Risk of Periodontitis in Patients with Gastroesophageal Reflux Disease: A Nationwide Retrospective Cohort Study

Background: Gastroesophageal reflux disease (GERD) is the most common digestive clinical problem worldwide that affects approximately 20% of the adult populations in Western countries. Poor oral hygiene has been reported to be associated with GERD as an atypical clinical complication. However, evidence showing the relationship between GERD and the risk of periodontitis is less clear. The present study aimed to use a retrospective cohort study design to further clarify the association between GERD and the subsequent risk of periodontitis. Methods: The risk of periodontitis in patients with GERD was investigated by analyzing epidemiological data from the Taiwan National Health Insurance Research Database from 2008 to 2018. We selected 20,125 participants with a minimum age of 40 years in the GERD group and 1:1 propensity-matched these with non-GERD individuals by sex, age, and comorbidities. The incidence of periodontitis was determined at the end of 2018. A Cox proportional hazards regression model was used to evaluate the risk of periodontitis in patients with GERD. Results: The overall incidence rate of the periodontitis risk was 1.38-fold higher (30.0 vs. 21.7/1000 person years, adjusted hazard ratio (aHR) = 1.36, 95% confidence interval (CI) = 1.28−1.45) in patients with GERD than in those without GERD. After stratified analyses for sex, age, and comorbidity, patients with GERD had a higher risk of periodontitis for age (aHR = 1.31, 95% CI = 1.20−1.42 for 40−54 years and aHR = 1.42, 95% CI =1.28−1.57 for 55−69 years), sex (aHR = 1.40, 95% CI = 1.28−1.54 for men and aHR = 1.33, 95% CI = 1.23−1.45 for women), and presence (aHR = 1.36, 95% CI = 1.27−1.45) and absence (aHR = 1.40, 95% CI = 1.21−1.62) of comorbidity than those without GERD. Among the GERD cohort, the risk for periodontitis was increased with an increasing number of emergency room visits (≥ 1 vs. <1, aHR = 5.19, 95% CI = 2.16−12.5). Conclusions: Our results revealed that patients with GERD have a higher risk of periodontitis development than those without GERD. Clinicians should pay more attention to identifying and managing periodontitis in patients with GERD.

Salivary changes in chronic kidney disease and in patients undergoing hemodialysis: a systematic review and meta-analysis

OBJECTIVES

This study is aimed at describing changes in salivary flow rate and ionic composition present in the saliva of chronic kidney disease (CKD) patients by assessing the pH, calcium, phosphate, and phosphorus concentrations and comparing them to healthy individuals, along with exploring the influence of hemodialysis on these parameters.

METHODS

The bibliographical search was performed in nine databases to find all types of studies, including observational clinical studies, without restrictions regarding publication year or language. Two reviewers selected the studies, extracted the data, and assessed the risk of bias using JBI tools. Random-effect meta-analysis was performed with the standardized mean difference (SMD) as effect estimate, at a 95% confidence interval.

RESULTS

Thirty-three studies were included in the qualitative synthesis and 31 studies were included in the meta-analysis. Chronic kidney disease patients presented lower salivary flow rate (SMD: - 1.73; 95% CI = - 2.14; - 1.31), higher pH (SMD: 1.57; 95% CI = 1.11; 2.03), and higher phosphorus concentration (SMD: 0.86; 95% CI = 0.63; 1.09) in saliva. Concurrently, salivary flow rate and pH presented significant changes after hemodialysis, with higher salivary flow rate (SMD: 0.53; 95% CI = 0.25; 0.81) and lower pH (SMD: - 0.53; 95% CI = - 0.88; - 0.19) in patients on hemodialysis treatment.

CONCLUSION

Chronic kidney disease patients present reduced salivary flow rate and increased pH and phosphorus concentration in saliva. Hemodialysis can increase the salivary flow rate of these patients.

Positive Effects of Saliva on Oral Candidiasis: Basic Research on the Analysis of Salivary Properties

The major causes of oral candidiasis include decreased salivary flow rate and the use of ill-fitting dentures. However, the relationships among prosthetic treatment, saliva, and Candida albicans have not been elucidated. This study aimed to examine the effects of prosthetic treatment and changes in saliva (mainly the salivary flow rate) on oral candidiasis symptoms. Participants requiring prosthetic treatment underwent testing for C. albicans, salivary flow rate, intraoral symptoms, and bite force at the initial visit and four months after treatment to evaluate pretreatment and post-treatment changes. The relationships among C. albicans, salivary flow rate, dentures, and intraoral symptoms were analyzed using multiple regression analysis. Denture treatment improved activity against C. albicans as well as the salivary flow rate, intraoral symptoms, and masticatory function. Multiple regression analysis revealed that changes in the stimulated salivary flow rate due to prosthetic treatment significantly improved C. albicans detection (p = 0.011), intraoral symptoms (p = 0.037), and bite force (p = 0.031). This study showed that prosthetic treatment improved salivary flow and intraoral symptoms and confirmed the influence of stimulated salivary flow rate changes.

The Oral Microbiome of Healthy Japanese People at the Age of 90

For a healthy oral cavity, maintaining a healthy microbiome is essential. However, data on healthy microbiomes are not sufficient. To determine the nature of the core microbiome, the oral-microbiome structure was analyzed using pyrosequencing data. Saliva samples were obtained from healthy 90-year-old participants who attended the 20-year follow-up Niigata cohort study. A total of 85 people participated in the health checkups. The study population consisted of 40 male and 45 female participants. Stimulated saliva samples were obtained by chewing paraffin wax for 5 min. The V3–V4 hypervariable regions of the 16S ribosomal RNA (rRNA) gene were amplified by PCR. Pyrosequencing was performed using MiSeq. Operational taxonomic units (OTUs) were assigned on the basis of a 97% identity search in the EzTaxon-e database. Using the threshold of 100% detection on the species level, 13 species were detected: Streptococcus sinensis, Streptococcus pneumoniae, Streptococcus salivarius, KV831974_s, Streptococcus parasanguinis, Veillonella dispar, Granulicatella adiacens, Streptococcus_uc, Streptococcus peroris, KE952139_s, Veillonella parvula, Atopobium parvulum, and AFQU_vs. These species represent potential candidates for the core make-up of the human microbiome.

Hematogenous apoptotic mechanism in salivary glands in chronic periodontitis

OBJECTIVE

The aim of the study is to investigate the apoptotic mechanism in salivary glands in the rat experimental periodontitis model.

DESIGN

A rat periodontitis model was prepared by using a ligature around the second upper molar. In the salivary (parotid and submandibular) glands and blood samples, putative apoptotic factors and pathway molecules were investigated in vivo and in vitro.

RESULTS

Four weeks of ligation (chronic periodontitis) demonstrated significant apoptotic atrophy of the salivary gland, but one week of ligation (initial periodontitis) did not. In the blood plasma, tumor necrosis factor-α (TNF-α) was increased in the periodontitis model, but interleukin-1β and -6 were not. TNF-α receptor type 1, which has an intracellular apoptotic pathway, was expressed in the salivary glands of rats. Western blot analysis of cultured rat primary salivary gland cells demonstrated that TNF-α induced cleavage of poly (ADP-ribose) polymerase (PARP) and caspase-3 in a dose-dependent manner, indicating apoptosis induction. Additionally, we found increment of circulating lymphocytes in the model. Expression of mRNA and immunoreactive cells for the B lymphocyte marker CD19 were increased in the salivary gland in the model. Western blotting showed that coculture with extracted B cells from the periodontitis model increased cleaved PARP in salivary gland cells.

CONCLUSIONS

Chronic periodontitis status leads to an increase in circulating TNF-α and B lymphocyte infiltration, resulting in apoptotic atrophy of the salivary gland as a periodontitis-induced systemic response.

Periodontal disease and effects of antipsychotic medications in patients newly diagnosed with schizophrenia: a population-based retrospective cohort

AIM

Compared with the general population, individuals with schizophrenia have a higher risk of periodontal disease, which can potentially reduce their life expectancy. However, evidence for the early development of periodontal disease in schizophrenia is scant. The current study investigated risk factors for periodontal disease in patients newly diagnosed with schizophrenia.

METHODS

We identified a population-based cohort of patients in Taiwan with newly diagnosed schizophrenia who developed periodontal disease within 1 year of their schizophrenia diagnosis. Treatment with antipsychotics and other medications was categorised according to medication type and duration, and the association between medication use and the treated periodontal disease was assessed through logistic regression.

RESULTS

Among 3610 patients with newly diagnosed schizophrenia, 2373 (65.7%) had an incidence of treated periodontal disease during the 1-year follow-up. Female sex (adjusted odds ratios [OR] 1.40; 95% confidence interval [CI] 1.20-1.63); young age (adjusted OR 0.99; 95% CI 0.98-0.99); a 2-year history of periodontal disease (adjusted OR 2.45; 95% CI 1.84-3.26); high income level (adjusted OR 2.24; 95% CI 1.64-3.06) and exposure to first-generation (adjusted OR 1.89; 95% CI 1.54-2.32) and secondary-generation (adjusted OR 1.33; 95% CI 1.11-1.58) antipsychotics, anticholinergics (adjusted OR 1.24; 95% CI 1.03-1.50) and antihypertensives (adjusted OR 1.91; 95% CI 1.64-2.23) were independent risk factors for periodontal disease. Hyposalivation - an adverse effect of first-generation antipsychotics (FGAs) (adjusted OR 2.00; 95% CI 1.63-2.45), anticholinergics (adjusted OR 1.27; 95% CI 1.05-1.53) and antihypertensives (adjusted OR 1.90; 95% CI 1.63-2.22) - was associated with increased risk of periodontal disease. Therefore, hypersalivation due to FGA use (adjusted OR 0.72; 95% CI 0.59-0.88) was considered a protective factor.

CONCLUSIONS

The current study highlights that early prevention of periodontal disease in individuals with schizophrenia is crucial. Along with paying more attention to the development of periodontal disease, assessing oral health regularly, helping with oral hygiene, and lowering consumption of sugary drinks and tobacco, emphasis should also be given by physicians to reduce the prescription of antipsychotics to the extent possible under efficacious pharmacotherapy for schizophrenia.

Assessing the association between unstimulated whole salivary flow rate (UWSFR) and oral health status among healthy adult subjects: A cross-sectional study

BACKGROUND

This study aimed to test the association between the unstimulated whole salivary flow rate (UWSFR) and the oral health status represented by dental and gingival status among healthy adult subjects.

MATERIAL AND METHODS

This work was a cross-sectional study of patients attending the undergraduate dental clinics at AlFarabi College for Dentistry and Nursing, Riyadh, Saudi Arabia. The study population consisted of 502 systemically healthy adults aged 18-35 years. UWSFR was collected for all study participants and expressed as ml/min. Oral health status was estimated using the Community Periodontal Index (CPI) and the Oral Hygiene Index-Simplified (OHI-S). The number of decayed teeth and the number of available teeth were also calculated to evaluate dental status.

RESULTS

The mean UWSFR was 0.42 (±0.3) ml/min, and the male participants significantly had more UWSFR than the females. UWSFR was significantly affected by CPI, OHI-S, body mass index (BMI) and gender as indicated in the univariate analysis. However, multiple regression analysis revealed that only gender was a significant predictor of UWSFR. The male subjects were shown to have a higher average of 0.133 ml/min than the females.

CONCLUSIONS

High BMI scores, moderate-to-severe gingivitis and low level of oral hygiene increased UWSFR. However, further longitudinal studies are recommended to test the role of salivary cytokine levels to validate the exact association between the UWSFR and the oral health status.

Hyposalivation and 10-year all-cause mortality in an elderly Japanese population

OBJECTIVE

To evaluate the association of salivary flow rate with all-cause mortality among older Japanese adults. We hypothesised that hyposalivation would be a marker for mortality.

BACKGROUND

Hyposalivation, which is an objectively measurable decrease in salivary flow, is highly prevalent among older adults. It is associated with malnutrition and poor general health.

METHODS

The study population comprised 600 community-dwelling Japanese adults (306 men and 294 women), who were 70 years old at baseline. They underwent stimulated salivary flow rate (SSFR) measurements and were followed up during a 10-year study period. After stratification by sex, the hazard ratios of all-cause mortality were estimated using Cox proportional hazards regression analysis comparing groups with and without hyposalivation (ie, SSFR < 0.7 mL/min).

RESULTS

The baseline prevalence of hyposalivation was 27.8% (85/306) among men and 47.3% (139/294) among women. During a mean (standard deviation) follow-up period of 104 (27) months, 80 deaths occurred: 60 (75.0%) deaths among men and 20 (25.0%) deaths among women. After adjusting for the number of remaining teeth, smoking status, exercise, hypoalbuminemia, diabetes and cardiovascular disease, hyposalivation at baseline was significantly associated with all-cause mortality among men (adjusted hazard ratio, 1.71; 95% confidence interval, 1.01-2.89). In contrast, no association between SSFR and all-cause mortality existed among women.

CONCLUSION

Hyposalivation could be a marker for all-cause mortality among older community-dwelling Japanese men. Future studies investigating the association between SSFR and cause-specific mortality are warranted.

Association between Salivary Hypofunction and Food Consumption in the Elderlies. A Systematic Literature Review

OBJECTIVES

This systematic literature review aims to summarize the existing scientific evidence about the association between a reduced salivary function and food consumption in elderly people.

METHODS

A validated search strategy in two databases (PubMed and ISI Web of Knowledge) was carried out and retrieved papers together with their reference lists were screened by two independent reviewers. The quality of the included studies was critically appraised via the Quality Assessment Criteria for Evaluating Primary Research Papers.

RESULTS

From the originally identified studies (n=391), only 15 articles (all cross-sectional studies) met the pre-fixed inclusion/exclusion criteria. The methodological quality of the included studies was in general good, although only 3 from 15 obtained the maximum score. The control of confounding factors was the quality variable more poorly rated in the selected studies. Salivary hypofunction was associated with a decrease of the objective chewing and swallowing abilities and taste perception. Moreover, most of the selected studies showed a relationship between salivary hypofunction and food consumption (in terms of appetite loss, unbalanced dietary intake and malnutrition), although no causality could be established.

CONCLUSIONS

This study highlights the fact that salivary hypofunction definition and measurements are different across the studies. Therefore, future research efforts should focus on establishing a gold standard to define and identify salivary hypofunction throughout life and on performing longitudinal studies controlling for confounding factors to establish causality.

High‑throughput sequencing analyses of oral microbial diversity in healthy people and patients with dental caries and periodontal disease

Recurrence of oral diseases caused by antibiotics has brought about an urgent requirement to explore the oral microbial diversity in the human oral cavity. In the present study, the high-throughput sequencing method was adopted to compare the microbial diversity of healthy people and oral patients and sequence analysis was performed by UPARSE software package. The Venn results indicated that a mean of 315 operational taxonomic units (OTUs) was obtained, and 73, 64, 53, 19 and 18 common OTUs belonging to Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria and Fusobacteria, respectively, were identified in healthy people. Moreover, the reduction of Firmicutes and the increase of Proteobacteria in the children group, and the increase of Firmicutes and the reduction of Proteobacteria in the youth and adult groups, indicated that the age bracket and oral disease had largely influenced the tooth development and microbial development in the oral cavity. In addition, the traditional ‘pathogenic bacteria’ of Firmicutes, Proteobacteria and Bacteroidetes (accounted for >95% of the total sequencing number in each group) indicated that the ‘harmful’ bacteria may exert beneficial effects on oral health. Therefore, the data will provide certain clues for curing some oral diseases by the strategy of adjusting the disturbed microbial compositions in oral disease to healthy level.

Stimulated salivary flow rate and oral health status

This study examined the relationship between stimulated salivary flow rate and oral health status in an adult population. Multinomial multivariate logistic regression analysis was used to examine the associations of salivary flow rate with dental caries status and periodontal status at the individual level among 2,110 Japanese adults with ≥10 teeth. Then, a spline model was used to examine the nonlinear relationship between salivary flow rate and teeth with dental caries or periodontal disease in multilevel analysis. Odds ratios were calculated for a 1.0-mL/min reduction in salivary flow rate at a point. After adjusting for confounding variables, participants with a flow rate ≤3.5 mL/min had significantly higher odds ratios for high caries status, and participants with a flow rate ≤1.4 mL/min had a higher odds ratio for broad periodontal disease, than did those with a flow rate >3.5 mL/min. In spline models, the odds ratio for teeth with dental caries or periodontal disease increased with reduced saliva secretion. The present findings suggest that decreased saliva secretion affects both dental caries and general periodontal health status.

Sialometry: aspects of clinical interest

Whole saliva is a multiglandular secretion complex consisting of gingival fluid, desquamated epithelial cells, microorganisms, products of bacterial metabolism, food debris, leukocytes mucus from the nasal cavity and the pharynx. Saliva has many functions, including tissue repair, tamponage, protection, digestion, taste, antimicrobial action, maintaining tooth integrity and antioxidant defense system. A decrease in salivary flow (hyposalivation) is a common disorder and it is estimated that approximately 20% of the general population have this alteration. Hyposalivation may be due to diabetes mellitus, hypothyroidism, dehydration, impaired glandular parenchyma by infectious processes, granulomatous diseases or autoimmune and inflammatory conditions (such as Sjogren's syndrome and rheumatoid arthritis), radiotherapy of head and/or neck region, or it may be associated with mood disorders, adverse effects caused by the use of some medications or even be idiopathic. Conventional therapies for the treatment of reduced saliva flow with the use of chemical and gustatory secretagogues are still limited. However, new alternatives have shown great perspective in the treatment of this disorder. To diagnose a patient as having chronic hyposalivation is a challenge in clinical practice and methods of salivary flow assessment are little known by rheumatologists. The serial evaluation of salivary flow is important for the diagnosis and prognosis of certain oral and systemic conditions. This review addresses some aspects related to the role of saliva, the consequences of hyposalivation and methods of salivary flow rate measurement, useful concepts in the daily practice of rheumatology.

Risk factors for reduced salivary flow rate in a Japanese population: the Hisayama Study

The purpose of this study was to determine distinct risk factors causing reduced salivary flow rate in a community-dwelling population using a prospective cohort study design. This was a 5-year follow-up survey of 1,377 community-dwelling Japanese individuals aged ≥40 years. The salivary flow rate was evaluated at baseline and follow-up by collecting stimulated saliva. Data on demographic characteristics, use of medication, and general and oral health status were obtained at baseline. The relationship between reduced salivary flow rate during the follow-up period and its predictors was evaluated after adjustment for confounding factors. In a multivariate logistic regression model, higher age and plaque score and lower serum albumin levels were significantly associated with greater odds of an obvious reduction in salivary flow rate (age per decade, odds ratio [OR] = 1.25, 95% confidence interval [CI] = 1.03-1.51; serum albumin levels <4 g/dL, OR = 1.60, 95% CI = 1.04-2.46; plaque score ≥1, OR = 1.53, 95% CI = 1.04-2.24). In a multivariate linear regression model, age and plaque score remained independently associated with the increased rate of reduced salivary flow. These results suggest that aging and plaque score are important predictors of reduced salivary flow rate in Japanese adults.

Saliva viscosity as a potential risk factor for oral malodor

OBJECTIVES

The objective of this study was to assess whether saliva viscosity, measured by a viscometer, was a predictor of oral malodor.

MATERIALS AND METHODS

The subjects were 617 patients who visited an oral malodor clinic. The organoleptic test (OT) was used for diagnosis of oral malodor. An oral examination assessed the numbers of teeth present and decayed teeth as well as the presence or absence of dentures. Further, periodontal pocket depths (PD), gingival bleeding, dental plaque and tongue coating were investigated. Unstimulated saliva were collected for 5 min. Saliva viscosity was measured with a viscometer. Logistic regression analysis with oral malodor status by OT as a dependent variable was performed. Possible confounders including age, gender, number of teeth present, number of decayed teeth, number of teeth with PD ≥ 4 mm, number of teeth with bleeding on probing, presence or absence of dentures, plaque index, area of tongue coating, saliva flow rate, saliva pH and saliva viscosity were used as independent variables.

RESULTS

Saliva viscosity (p = 0.047) along with the number of teeth with PD ≥4 mm (p = 0.001), plaque index (p = 0.037) and area of tongue coating (p < 0.001) were significant variables for oral malodor. Subjects with a higher number of teeth with PD ≥ 4 mm (OR = 1.32), plaque index (OR = 2.13), area of tongue coating (OR = 3.17) and saliva viscosity (OR = 1.10) were more likely to have oral malodor compared to those with lower values.

CONCLUSIONS

The results suggested that high saliva viscosity could be a potential risk factor for oral malodor.

Relationship between xerostomia and gingival condition in young adults

BACKGROUND AND OBJECTIVE

Xerostomia is a subjective symptom of dryness in the mouth. Although a correlation between xerostomia and oral conditions in the elderly has been reported, there are few such studies in the young adults. The aim of this study was to examine the relationship of xerostomia with the gingival condition in university students.

MATERIAL AND METHODS

A total of 2077 students (1202 male subjects and 875 female subjects), 18-24 years of age, were examined. The disease activity and severity of the gingival condition were assessed as the percentage of teeth with bleeding on probing (%BOP) and the presence of teeth with probing pocket depth of ≥ 4 mm, respectively. Additional information on xerostomia, oral health behaviors, coffee/tea intake and nasal congestion was collected via a questionnaire. Path analysis was used to test pathways from xerostomia to the gingival condition.

RESULTS

One-hundred and eighty-three (8.8%) students responded that their mouths frequently or always felt dry. Xerostomia was related to %BOP and dental plaque formation, but was not related to the presence of probing pocket depth ≥ 4 mm. In the structural model, xerostomia was related to dental plaque formation (p < 0.01), and a lower level of dental plaque formation was associated with a lower %BOP. Xerostomia was associated with coffee/tea intake (p < 0.01) and nasal congestion (p < 0.001).

CONCLUSION

Xerostomia was indirectly related to gingival disease activity through the accumulation of dental plaque. Nasal congestion and coffee/tea intake also affected xerostomia. These findings suggest that xerostomia should be considered in screening for gingivitis risk in young adults.

The relationship between gastroesophageal reflux disease and chronic periodontitis

Background/Aims

The most common cause of chronic periodontitis is poor oral hygiene. Gastroesophageal reflux disease (GERD) enhances the proximal migration of gastric contents and may cause poor oral hygiene. We hypothesized that GERD may increase thse risk of chronic periodontitis and investigated this potential relationship.

Methods

A retrospective cross-sectional study was conducted in outpatients between January 1, 2010, and April 30, 2012. GERD was defined as being present based on at least two of the following criteria: etiologic agent(s), identifiable signs and symptoms, and consistent anatomic alterations. A total of 280 patients with chronic periodontitis and 280 controls were analyzed. Information regarding patient demographics and other potential confounding factors for chronic periodontitis were collected through individual medical records.

Results

GERD was revealed to be independently associated with an increased incidence of chronic periodontitis (odds ratio [OR], 2.883; 95% confidence interval [CI], 1.775 to 4.682). The other three variables of dental caries (OR, 1.531; 95% CI, 1.042 to 2.249), tobacco use (OR, 2.335; 95% CI, 1.461 to 3.730), and history of medication (calcium channel blocker, cyclosporine, or phenytoin) (OR, 2.114; 95% CI, 1.160 to 3.854) were also determined to be independent risk factors.

Conclusions

The present study supported our hypothesis that GERD can be a risk factor for chronic periodontitis.

An assessment of periodontal health in patients with schizophrenia and taking antipsychotic medication

BACKGROUND AND OBJECTIVE

Severe periodontal disease is prevalent among patients with schizophrenia and is caused by the side effect of their medication, poor dental hygiene and smoking. The objective of this study was to evaluate whether the rate of periodontal disease could be modulated by changing the salivary flow rate (SFR) because of the use of antipsychotic medications in patients with schizophrenia.

METHODS

Group A (n=33) included patients who used medications that may cause xerostomia, or dry mouth and Group B (n=20) included patients who used medications that may cause sialorrhea, an excessive secretion of saliva. The participants' periodontal status was assessed using the plaque index (PI), assessing bleeding on probing (BoP), probing pocket depth (PPD) and clinical attachment levels (CAL).

RESULTS

The mean of PI and BoP was significantly higher in Group A than in Group B (P<0.001), but the PPD, CAL and decayed, missing and filled teeth (DMFT) scores were not significantly different in the two groups according to the statistical results (P>0.05).

CONCLUSIONS

The researcher concluded that there is a high risk of periodontal disease among patients with schizophrenia, and there is an even higher risk of periodontal disease induced by medication that increased SFR. Preventive dental protocol should be increased during the dental health care of this disadvantaged patient group.

Effect of saliva viscosity on the co-aggregation between oral streptococci and Actinomyces naeslundii

BACKGROUND

The co-aggregation of oral bacteria leads to their clearance from the oral cavity. Poor oral hygiene and high saliva viscosity are common amongst the elderly; thus, they frequently suffer from pneumonia caused by the aspiration of oral microorganisms.

OBJECTIVES

To examine the direct effect of saliva viscosity on the co-aggregation of oral streptococci with actinomyces.

MATERIALS AND METHODS

Fifteen oral streptococcal and a single actinomyces strain were used. Co-aggregation was assessed by a visual assay in phosphate buffer and a spectrophotometric assay in the same buffer containing 0-60% glycerol or whole saliva.

RESULTS

Nine oral streptococci co-aggregated with Actinomyces naeslundii ATCC12104 in the visual assay and were subsequently used for the spectrophotometric analysis. All tested strains displayed a decrease in co-aggregation with increasing amounts of glycerol in the buffer. The co-aggregation of Streptococcus oralis with A. naeslundii recovered to baseline level following the removal of glycerol. The per cent co-aggregation of S. oralis with A. naeslundii was significantly correlated with the viscosity in unstimulated and stimulated whole saliva samples (correlation coefficients: -0.52 and -0.48, respectively).

CONCLUSION

This study suggests that saliva viscosity affects the co-aggregation of oral streptococci with actinomyces and that bacterial co-aggregation decreases with increasing saliva viscosity.

Serum markers of chronic dehydration are associated with saliva spinability

Findings of a relationship between saliva and dehydration have been observed, but the precise nature of these relationships is unclear and no evidence of a direct link has been found. In particular, no study reports a relationship between chronic dehydration and saliva conditions in community-dwelling older adults. This study aimed to identify whether salivary conditions are sensitive to body hydration markers in an elderly population. A total of 403 subjects aged 76 years participated in the study. Stimulated saliva flow rate and spinability of saliva were measured. In addition, determinations of serum levels of uric acid, blood urea nitrogen (BUN), creatinine, sodium and potassium were made. Dehydration was defined as uric acid >/= 7 mg dL(-1) according to the standard value. The salivary spinability were significantly associated with the concentration of uric acid (OR=2.06, P=0.044) according to multiple logistic regression analysis. In addition, after adjusting for gender, the uric acid concentration and the salivary spinability was significantly associated with BUN, potassium and creatinine levels. The subjects with high uric acid levels (>/= 7 mg dL(-1)) had the most elastic saliva. Both BUN and serum creatinine are the most commonly used indicators of renal function. Therefore, our findings might demonstrate that older adults who are dehydrated showed highly elastic saliva, which was associated with renal function. In conclusion, this study suggests that there is a significant relationship between chronic dehydration status and salivary spinability level.

Relationship between bite force and salivary flow in older adults

OBJECTIVE

To examine the relationship between bite force and stimulated salivary flow rate in older adults.

STUDY DESIGN

The study sample consisted of 934 independent-living, cognitively healthy Japanese older adults 60 to 84 years of age. The maximal bite force was measured with pressure-sensitive sheets, and stimulated whole saliva was collected using the mastication method.

RESULTS

The mean stimulated salivary flow rate was 1.36 +/- 0.97 mL/min. In bivariate analysis, the stimulated salivary flow rate was significantly lower in females and subjects with daily multiple medications (P < .01). Multiple linear regression analysis showed that the stimulated salivary flow rate was significantly associated with sex (standardized partial regression coefficient: partial beta = .22; P < .001), bite force (partial beta = .18; P < .001), and multiple daily medications (partial beta = -.12; P < .001).

CONCLUSIONS

It is suggested that reduced bite force is associated with a decline in stimulated whole salivary flow rate independent of sex and medication in older adults.