Evaluation of unstimulated and stimulated parotid salivary flow rate in Israeli healthy subjects aged 60 years and older

Saliva plays a critical role in the maintenance oral health. Clinical studies showed that 25% of the elderly population suffers from oral dryness and its related complaints. Studies that measured parotid gland salivary flow rate, both unstimulated and stimulated, in healthy older individuals did not find age-related functional changes. However, histological studies have revealed an age-dependent reduction in the parotid acinar tissue component. To our knowledge there are still no reports of the parotid salivary flow rate in the elderly population in Israel. The goal of this study was to evaluate the rate of the parotid unstimulated and stimulated salivary flow rate among healthy Israeli people aged over 60 years old--the findings may serve as basic standard values to be compared to data collected from patients with complaints of xerostomia and to data reported in other studies. Thirty healthy volunteers aged 60 to 77 years (average 64.7), 23 females and 7 males, were evaluated. Twenty five of the subjects used to live in kibbutzim and 5 lived in a city. The mean unstimulated parotid salivary secretion rate was 0.044+/-0.063 ml/min and the mean stimulated secretion was 0.163+/-0.291 ml/min. Those rates were found to be lower than the unstimulated and stimulated parotid salivary flow rates reported in most other studies. Fourteen (43.3) of the subjects had zero flow rate at rest. This figure was higher then the 20% zero flow at rest that was reported by others among persons with a broader age range. No significant differences were recorded in the parotid salivary flow, both unstimulated and stimulated, between subjects living in the kibbutzim compared to those living in the city. Similar to other studies the differences in the secretion rates between men and women were non significant. The low mean unstimulated and stimulated salivary flow rates, and the high prevalence of no flow at rest can be explained by the fact that saliva collections were done during the very warm Israeli summer and it is speculated that the subjects might be dehydrated. General dehydration can be observed in warm climate areas. No significant differences were found in the parotid salivary flow rates, (unstimulated and stimulated), between the city subjects compared to those from the kibbutzim. Further similar studies in different weather conditions (winter-summer) are needed to establish data of the normal parotid salivary secretion in the over 60 years old Israeli population.     

The effects of electrostimulation on parotid saliva flow: a pilot study

OBJECTIVE: Saliva is a critical fluid necessary for oral health. Medications, radiation therapy, and systemic conditions can decrease salivary function and increase a patient's risk for caries and other oral infections. Palliative management of xerostomia includes wetting agents such as ice chips and saliva substitutes. Systemic agents stimulate salivary flow but often have unfavorable side effects. All have met with limited success. The purpose of this study is to assess the effectiveness of transcutaneous electric nerve stimulation (TENS) as a means of stimulating salivary function in healthy adult subjects. STUDY DESIGN: Twenty-two healthy, adult subjects with no history of salivary gland disorder enrolled in the protocol. The TENS electrode pads were placed externally on the skin overlying the parotid glands. Unstimulated saliva was collected for 5 minutes via the Carlson-Crittenden cup into preweighed vials using standardized collection techniques. The TENS unit was then activated and stimulated saliva collected for an additional 5 minutes. RESULTS: Fifteen of 22 subjects demonstrated increased parotid salivary flow when stimulated via the TENS unit. Five experienced no increase and 2 experienced a decrease. The mean unstimulated salivary flow rate was 0.02418 mL/min (SD 0.03432) and mean stimulated salivary flow rate was 0.04946 mL/min (SD 0.04328). Statistical analysis of flow rates utilizing the paired t test demonstrated the difference to be statistically significant, P < .001. In 7 subjects with 0 baseline flow, 5 continued to have no flow. CONCLUSIONS: The TENS unit was effective in increasing parotid gland salivary flow in two-thirds of healthy adult subjects. A further study in a cohort of patients with salivary gland disorders is warranted.     

The relationship between salivary histatin levels and oral yeast carriage

Candida species are common commensal inhabitants of the oral cavity. Human saliva contains antifungal proteins called histatins. We tested the hypothesis that oral yeast status is related to salivary histatin levels. Thirty subjects were divided into two groups based on the presence (n = 15) or absence (n = 15) of yeast on oral mucosa surfaces. Unstimulated and stimulated submandibular and sublingual and parotid saliva was collected from each subject. Salivary flow rates were measured and histatin concentrations were determined in the stimulated saliva samples. The yeast colony positive group showed lower median unstimulated parotid saliva flow rates as well as lower median concentrations of total histatins in submandibular and sublingual saliva. There was a negative correlation between yeast colony-forming units and unstimulated parotid saliva flow rates and between yeast colony-forming units and submandibular and sublingual saliva histatin concentration and secretion. The results suggest that oral yeast status may be influenced by unstimulated parotid saliva flow rates and by submandibular and sublingual histatin concentration and secretion.     

The physiology of salivary secretion

Saliva in the mouth is a biofluid produced mainly by three pairs of major salivary glands – the submandibular, parotid and sublingual glands – along with secretions from many minor submucosal salivary glands. Salivary gland secretion is a nerve‐mediated reflex and the volume of saliva secreted is dependent on the intensity and type of taste and on chemosensory, masticatory or tactile stimulation. Long periods of low (resting or unstimulated) flow are broken by short periods of high flow, which is stimulated by taste and mastication. The nerve‐mediated salivary reflex is modulated by nerve signals from other centers in the central nervous system, which is most obvious as hyposalivation at times of anxiety. An example of other neurohormonal influences on the salivary reflex is the circadian rhythm, which affects salivary flow and ionic composition. Cholinergic parasympathetic and adrenergic sympathetic autonomic nerves evoke salivary secretion, signaling through muscarinic M3 and adrenoceptors on salivary acinar cells and leading to secretion of fluid and salivary proteins. Saliva gland acinar cells are chloride and sodium secreting, and the isotonic fluid produced is rendered hypotonic by salivary gland duct cells as it flows to the mouth. The major proteins present in saliva are secreted by salivary glands, creating viscoelasticity and enabling the coating of oral surfaces with saliva. Salivary films are essential for maintaining oral health and regulating the oral microbiome. Saliva in the mouth contains a range of validated and potential disease biomarkers derived from epithelial cells, neutrophils, the microbiome, gingival crevicular fluid and serum. For example, cortisol levels are used in the assessment of stress, matrix metalloproteinases‐8 and ‐9 appear to be promising markers of caries and periodontal disease, and a panel of mRNA and proteins has been proposed as a marker of oral squamous cell carcinoma. Understanding the mechanisms by which components enter saliva is an important aspect of validating their use as biomarkers of health and disease.     

Salivary LL-37 secretion in individuals with Down syndrome is normal

Antimicrobial peptides play an important role in the innate immune response. Deficiency in salivary LL-37 antimicrobial peptide has been implicated in periodontitis in patients with morbus Kostman syndrome. Down syndrome is associated with periodontitis, diminished salivary flow, and salivary immunoglobulin deficiency. In the present study, levels of LL-37 and its hCAP18 precursor were measured in saliva samples from young individuals with Down syndrome and compared with levels in those from age-matched healthy controls. LL-37 and human cathelicidin antimicrobial protein (hCAP18) were detected in whole but not in parotid saliva. hCAP18 was more abundant than LL-37. The concentrations of salivary hCAP18 and LL-37 were found to be higher in individuals with Down syndrome than in healthy controls, but their secretion rates were similar. We concluded that, while the adaptive immunity of individuals with Down syndrome is impaired at the oral mucosa, the secretion rate of the LL-37 component of the innate immune system is normal.     

Levels of parotid and submandibular/sublingual salivary immunoglobulin A in response to experimental gingivitis in humans

Salivary secretory IgA (s-IgA) is considered to act as an important first line of defense mechanism in the oral cavity. It has therefore been suggested that an increased antigenic load would induce an increase in salivary IgA production. This study investigated the pure glandular levels of salivary IgA in parotid and submandibular/sublingual (SM/SL) saliva during plaque accumulation leading to experimental gingivitis. Starting from regular oral hygiene, 14 healthy, nonsmoking men refrained from all oral hygiene measures for 12 days. On days –2, 0, 3, 6, and 12 a plaque index, a bleeding index, and unstimulated and stimulated saliva from the parotid and the SM/SL glands were measured. Salivary IgA was quantified using a sandwich ELISA. All subjects developed gingivitis as measured by a bleeding index. Compared to baseline the salivary flow rate was increased on day 12. Regarding the secretion rate of IgA there was a statistically significant increase in stimulated parotid saliva but not SM/SL saliva compared to baseline after 6 and 12 days without oral hygiene. No significant changes were observed for the concentration of IgA during the trial. Thus, in healthy subjects with regular oral hygiene the development of plaque induced gingivitis is associated with increased salivary gland output and increased total IgA output levels in stimulated parotid saliva but not in SM/SL saliva.     

Feeling of dry mouth in relation to whole and minor gland saliva secretion rate

Previous reports indicate an association between whole saliva secretion rate and xerostomia, but the association is not always found in individuals complaining of dry mouth. In the present study, we hypothesised that the minor salivary gland secretions could affect subjective feelings of oral dryness in individuals with normal or low whole saliva secretion rate. 142 individuals, aged 18-82 years, participated in the study. Feelings of oral dryness were assessed separately for day- and nighttime by visual analogue scales. Resting and stimulated whole saliva flow rates were measured by conventional methods, and minor palatal, buccal and labial saliva secretion rates by the Periotron method. Twenty-three percent of the women and 15% of the men reported feelings of dry mouth during day and night. The results showed statistically significant lower resting and stimulated whole and minor labial gland saliva secretion rates in subjects reporting oral dryness during both day and night compared with non-complainers. In groups of individuals with normal simulated whole saliva secretion, those who complained from dry mouth both day and night had statistically significant lower labial secretion rate compared with those who had no complaints. Although not statistically significant, this difference was seen also in the groups with fewer individuals who had low whole saliva flow. In summary, our findings suggested that the labial gland saliva might affect subjective feelings of dry mouth both in individuals with normal and subnormal whole saliva flow.     

Relationship of chewing-stimulated whole saliva flow rate and salivary gland size

OBJECTIVE: We have recently reported that unstimulated whole saliva flow rates (UWSFR) correlate positively with salivary gland sizes and body profiles of weight and body mass indices. In the present study, the correlations of chewing-stimulated whole saliva flow rates (CWSFR) with salivary gland sizes and the body profiles were investigated, and the results were compared with those of UWSFR. DESIGN: Saliva samples were collected from 24 healthy young males and 26 females by the spitting method while chewing paraffin and the CWSFRs were measured. UWSFR and the estimated sizes of the three major salivary glands in our previous study were used. RESULTS: The CWSFRs in all subjects and in males correlated positively with UWSFR, but not in females. The CWSFRs in all subjects correlated positively with parotid and/or submandibular gland sizes, weights and body mass indices, just as with UWSFR; however, the correlation coefficients with salivary gland sizes were smaller than those of UWSFR. In contrast to the results of UWSFR, the correlation coefficients of the CWSFRs with parotid gland sizes in all subjects were larger than those with the sizes of the submandibular glands. The CWSFRs in males correlated only with parotid gland sizes, and those in females did not correlate with any of the parameters. CONCLUSIONS: The results suggest that the larger the size of the salivary glands, the greater the CWSFR, at least in males.     

Oral mucosal status and major salivary gland function

Normal salivary function is considered to be critical for the maintenance of healthy oral mucosa. However, few studies have examined mucosal changes in patients with objectively documented salivary gland performance. In the present report, the mucosal status of 298 subjects being evaluated in a dry mouth clinic was assessed. A complete oral examination was performed and unstimulated and stimulated salivary samples were collected separately from the parotid and submandibular/sublingual glands. Data were analyzed according to diagnosis and salivary output after the assignment of an oral mucosal rating to each subject. In general, the mucosal surfaces were well preserved and infections were not seen. Patients evaluated for Sj?gren's syndrome and radiation-induced xerostomia had the lowest salivary gland performance but displayed a mucosal status similar to denture-wearing healthy subjects or patients with normal salivary flow who had idiopathic xerostomia. However, those patients with a total lack of salivary flow rarely had normal-appearing oral mucosa. These results confirm a role for saliva in oral mucosal preservation and also suggest that other factors may act to maintain oral mucosal integrity.     

Antimicrobial proteins in human unstimulated whole saliva in relation to each other, and to measures of health status, dental plaque accumulation and composition.

Saliva antimicrobial proteins may interact in a common system to influence the oral ecology. Clinical studies of antimicrobial protein action thus may require a multiple-protein approach. Multivariate statistical methods have been used to describe possible patterns of interaction for lysozyme, lactoferrin, salivary peroxidase and secretory IgA in stimulated parotid saliva. However, oral microbes are most likely to encounter antimicrobial proteins in mixed resting saliva. Relationships among levels of lysozyme, lactoferrin, salivary peroxidase, and secretory IgA therefore were investigated in whole saliva from 216 subjects, and an attempt made to relate interperson variation in those proteins to differences in health and status, and dental plaque accumulation and composition. All proteins were significantly (alpha = 0.05) correlated with each other (r = 0.38-0.52, p less than 0.001). There was only one axis of common variation among proteins, and that axis was significantly correlated (p less than 0.001) with total protein (r = 0.84) and flow rate (r = -0.56). That pattern deviated from the previous finding that proteins of acinar origin tended to vary independently from proteins of ductal origin in stimulated parotid saliva. The difference between parotid and whole saliva may reflect constitutive secretion of all proteins at low levels of stimulation. Common variation of unstimulated saliva proteins suggests that antimicrobial actions can be compared in subjects at population extremes. There were no significant associations between antimicrobial proteins in whole saliva and measures of health status or plaque accumulation. However, the proportions of Streptococcus sanguis were significantly correlated with lysozyme (r = -0.26), lactoferrin (r = -0.34), peroxidase (r = -0.30), total protein (r = -0.37), flow rate (r = 0.24) and principal-components scores (r = -0.33) in a subset of subjects (n = 85) where commercial biochemical tests were used to supplement species identification by colony morphology. Those findings may indicate that saliva antimicrobial proteins can affect the composition of dental plaque.     

Stress response to surgical procedures in the submandibular region and its influence on salivary secretion in mice

Saliva stimulated by pilocarpine was collected from the mouths of adult ICR male mice after either submandibular-sublingual gland (SM-SL) exposure and SM-SL removal under pentobarbital anaesthesia. Salivary flow rates decreased and salivary protein concentrations increased after both surgical procedures. Serum cortisol was elevated after the operations. Salivary protein separation patterns on sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE) from surgically treated animals were very similar to those from mice given an alpha 1-adrenergic agonist (phenylephrine), but differed significantly from those given a beta-adrenergic agonist (isoproterenol). When the SM-SL was completely removed (i.e. parotid saliva), protein concentrations also dramatically increased. The SDS-PAGE protein separation pattern in the mice whose SM-SL had been removed was very similar to that in those whose SM-SL had been exposed. Hence, a surgical insult in the submandibular region in mice enhances the secretion of salivary protein, mainly in response to alpha 1-adrenergic receptor stimulation in the parotid gland. This study suggests the usefulness of alpha 1-adrenergic receptor-stimulated parotid salivary protein as a marker of surgical insult.     

Effect of photic stimuli on rat salivary glands. Role of sympathetic nervous system

Saliva secretion during feeding facilitates chewing, swallowing and other oral functions. Between meals, a "resting saliva" is elicited to allow speaking and contribute to maintain soft and hard tissues health. Chewing is the main stimulus for "stimulated saliva" secretion. Mouth dryness and other less well known stimuli control "resting saliva". In humans the stimulus of the light increases the parotid saliva flow rate. Saliva secretion occurs in response to a reflex. Both motor branches of the autonomous nervous system drive efferent outputs to the salivary glands. Cellular bodies of sympathetic motor fibers innervating salivary glands are located in the superior cervical ganglia. A multisynaptic pathway couples the superior cervical ganglia to hypothalamic areas related to the control of autonomous and endocrine functions. Projections from suprachiasmatic nuclei involved in circadian rhythms control reach those areas. Salivary glands postsynaptic beta-adrenoceptors control synthesis and secretion of proteins. Postsynaptic alpha 2-adrenoceptors modulate salivary responses mediated by alpha 1 and beta-adrenoceptors. Parotid alpha-amylase circadian rhythm in suckling rats, suggest that the sympathetic nervous system mediates an effect of light on saliva secretion. Analysis of: 1) parotid fine structure, 2) submandibular secretory response to adrenergic agonists, and 3) submandibular 3H-clonidine binding to alpha 2-adrenoceptors, demonstrated that an increase of sympathetic reflex activity occurs in salivary glands of rats chronically exposed to constant light. Similar effects were observed in rats chronically exposed to immobilization stress. Catecholamine biosynthetic enzyme mRNA levels in adrenal glands and superior cervical ganglia suggest that changes induced by light on salivary sympathetic reflex activity are mediated by plasma catecholamines released by adrenal glands. Post and presynaptic alpha 2 adrenoceptors could play an important role in saliva secretion control when light or stress stimuli modify the sympathoadrenal system.     

Stimulated whole saliva components in children with Down syndrome

The authors report on the components of stimulated whole saliva from children with Down syndrome—including pH, flow rate, sialic acid and protein concentrations, and amylase and peroxidase activity. Saliva samples were collected from 35 children aged 6–10 years. Of the participants, 17 had Down syndrome and 18 did not. To stimulate saliva production, the children chewed a piece of parafilm for 10 minutes before the sample was collected. Soon after collecting the saliva sample, the authors measured pH using a portable pH-meter. Sialic acid levels were determined with a thiobarbituric acid assay. Protein content was determined with Folin's phenol reagent. Amylase was assayed and the authors measured the maltose produced by the breakdown of starch and peroxidase using ortho-dianisidine.
No statistically significant difference was observed in levels of sialic acid (free and total) between the two groups. Protein concentration was about 36% higher in the group with Down syndrome. However, the salivary flow rate, pH, and amylase and peroxidase activities were lower among the children with Down syndrome.     

Salivary gland function and changes in patients with oral lichen planus

Abstract – Saliva analysis, sialography and histopathologic examination of labial salivary glands were performed on patients with oral lichen planus. Diseases connected with salivary gland function were also recorded. Saliva analysis regarding secrection rate, pH and buffer capacity in unstimulated and stimulated saliva was permormed on 39 patients. 87% of the patients exhibired a low or very low unstimulated secretion rate, the mean value being 0.14 ml/min. The rate of stimulated saliva, pH and buffer capicity did not deviate from normal reference values. Sialographic examination was performed on 18 patients, corresponding to 36 major salivary glands. Radiologic changes were seen in 89% patients. Histopathologic examination was performed on 15 patients. Lymphocytic infiltration, acinar atrophy, fibrosis, fatty degeneration or ducral changes were observed in the minor glands of all patients. Different degrees of acinar atrophy were present in 93% of the patients. Lymphorytic infiltration was seen in 12 patients (80%) of whom three exhibited focal accumulation as in Sjögren's syndrome. Since decreased salivary secretion and symptoms of joint diseases and keratoconjunctivitis sicca were frequently present, over a third of the patients showed clinical signs comparable to those of Sjögren's syndrome. A high frequency of gastrointestinal and endocrine diseases was also recorded, which suggests that a general exo and endocrine influence may be present in patients with oral lichen planus.     

The effect of food consistency and dehydration on reflex parotid and submandibular salivary secretion in conscious rats

Changes in salivary secretion with different consistency of diet and dehydration were studied in male Wistar rats under unrestricted conditions. To measure the salivary secretion, a stop-flow method was used. There was little unstimulated salivary secretion from the parotid and submandibular glands, but eating solid, powdered, and liquid diets induced parotid and submandibular saliva. There was no significant change in the volume and flow rate of saliva in bilateral parotid glands during the eating of solid diets. The solid and powdered diets induced significantly more salivary secretion from the parotid gland than did the liquid. The salivary flow rate with solid diets was significantly greater from the parotid gland than from the submandibular. On the other hand, the salivary flow rate with the liquid diet was significantly smaller from the parotid gland than from the submandibular. Appreciable amounts of submandibular saliva, but little parotid saliva were secreted during grooming. Clearly, parotid and submandibular saliva have different roles in the rat. When injected intraperitoneally with 1.5 M NaCl solution or water-deprived for 24 h, rats took longer to eat the solid diets, and had increased salivary volume and decreased flow rate from the parotid gland. These results indicate that the moisture content of the diet and the dryness of the mouth alters the volume of parotid saliva secreted in rats and show that parotid saliva plays an important part in mastication and swallowing.     

Electrolytes in stimulated whole saliva in individuals with hyposalivation of different origins

There are reasons to believe that changes in the secretion rate of saliva as well as changes in its protein and electrolyte composition promote the growth of micro-organisms associated with oral disorders. Knowledge of the electrolytes in the saliva of those with hyposalivation might therefore be of value in designing oral health-promoting measures. In this study, electrolytes in stimulated whole saliva were analysed in individuals with hyposalivation due to radiation therapy in the head and neck region (RT group), primary Sj?gren's syndrome (pSS group), neuroleptic treatment (Neuro group), and to medication or of unknown origin (Unknown group). The bicarbonate concentration was significantly lower in all four hyposalivation groups compared with controls. The bicarbonate concentration, which in normal conditions is positively correlated with the salivary secretion rate, was lower in the Neuro group than in the RT and Sj?gren's groups despite a stimulated secretion rate about twice as high. Furthermore, the Neuro group had the highest phosphate concentration. The RT and Sj?gren's groups tended to have increased sodium concentrations. For potassium and calcium, the RT group had significantly higher concentrations than the other hyposalivation groups and the controls. The substantial increase in calcium and decrease in bicarbonate suggest that the function of the parotid glands is more affected than that of the other salivary glands. The results also indicate a contribution of plasma to the electrolyte concentrations determined in whole saliva in the RT and Sj?gren's groups. In conclusion, in individuals with hyposalivation the concentrations of electrolytes in stimulated whole saliva seem to be more related to the reason for the hyposalivation than to the salivary secretion rate.     

Protein composition of whole and parotid saliva in healthy and periodontitis subjects

Cystatins are physiological inhibitors of cysteine proteinases and they are widely distributed in human tissues and body fluids including saliva. We previously reported an increased cystatin activity in whole saliva of gingivitis and periodontitis subjects. Based on this result we decided to investigate the type and origin of cystatins involved in this increased cystatin activity by collecting both whole and parotid saliva of 25 healthy and 30 periodontitis subjects. Saliva samples were quantified for cystatins S and C by enzyme-linked immunosorbent assay and cystatin activities were measured toward papain. Besides, three other salivary proteins were determined: the plasma protein albumin, the typical parotid derived amylase and the salivary immunoglobulin IgA. The present investigation shows that levels of total protein and cystatin activity as well as the levels of glandular derived proteins amylase and cystatin C were significantly higher in whole and parotid saliva of subjects with periodontitis than in healthy controls. Cystatin S, the major salivary cystatin. however was higher in the whole saliva of the healthy group. Whole saliva concentrations of albumin and IgA, originating from sources other than the glandular cells, were not different between healthy and periodontitis subjects and were also not correlated with the typical salivary gland proteins. In conclusion, this study provides additional evidence that the human salivary glands may respond to an inflammatory disease of the oral cavity, periodontitis, by enhanced synthesis of some acinar proteins.     

Association of salivary flow rates with maximal bite force

Mean salivary secretion and bite force decrease with advancing age. Previous studies have shown that salivary flow rates are influenced by mastication. In the present study, we examined the relationship between salivary flow rates and maximal bite force in a community-based sample of men and women 35 years of age or older. Salivary flow rates for unstimulated whole and unstimulated submandibular/sublingual (SMSL) saliva as well as citrate-stimulated parotid and SMSL saliva were measured in 399 subjects. Bite force was assessed with a bilateral force transducer. Pearson correlation analysis yielded significant positive correlations between bite force and flow rates for unstimulated whole saliva (r = 0.24, p < 0.0001), stimulated parotid saliva (r = 0.13, p < 0.03), unstimulated SMSL (r = 0.14, p < 0.0001), and stimulated SMSL (r = 0.16, p < 0.003). When adjusted for age and gender, the partial correlations between bite force and salivary flow rates remained significant for unstimulated whole saliva (r = 0.10, p < 0.05), stimulated parotid saliva (r = 0.13, p < 0.02), and stimulated SMSL saliva (r = 0.14, p < 0.006). Subjects were divided into four groups based on their maximal bite force score (low, medium low, medium high, and high). For each saliva type, the flow rate of the high-bite-force group was significantly greater than that of the low-bite-force group as well as that of the medium-high-bite-force group. These results confirm an age-related decrease in bite force and salivary flow rates and show that, regardless of age or gender, bite force is correlated with salivary flow.     

Oral manifestations and salivary flow rate, pH, and buffer capacity in patients with end-stage renal disease undergoing hemodialysis.

OBJECTIVE: The aim of this study was to investigate oral manifestations and salivary changes in patients with end-stage renal disease undergoing hemodialysis. STUDY DESIGN: Eighty-two patients undergoing hemodialysis for renal insufficiency were examined; 22 of these patients were randomly selected for salivary tests. Unstimulated whole saliva and stimulated parotid saliva were collected, and flow rate, pH, and buffer capacity were examined. Twenty-two healthy volunteers were included as controls. RESULTS: Uremic odor, dry mouth, and taste change were common symptoms. Petechia and/or ecchymosis and increase of tongue coating were major signs. The flow rates of unstimulated whole and stimulated parotid saliva were decreased in the patient group. The pH and buffer capacity of unstimulated whole saliva were increased in the patient group, but stimulated parotid saliva did not show any significant differences. CONCLUSIONS: Patients with end-stage renal disease undergoing hemodialysis showed apparent oral and salivary changes. The results help us understand the relationship between oral changes and renal insufficiency.