Correction to: Dry mouth: saliva substitutes which adsorb and modify existing salivary condition films improve oral lubrication

Clinical Oral Investigations - After publication of this paper, the authors observed that that figure 6 appears before figure 5.     

Burning mouth syndrome and saliva: detection of salivary trace elements and cytokines

Background: Burning mouth syndrome (BMS) is considered a syndrome with an unknown cause. Roles of various trace elements and cytokines in saliva have been implicated in the development of BMS. The aim of the present study was to compare the levels of salivary trace elements [magnesium (Mg), zinc (Zn), copper (Cu)] and interleukin (IL)‐2 and IL‐6, and to search for a correlation between depression/anxiety and salivary trace elements and cytokines in BMS patients and controls. Methods: Thirty patients with BMS and 30 matched healthy controls participated in the study. Unstimulated saliva was collected from participants and salivary flow rates were determined. Mg, Zn and Cu levels were determined by atomic absorbance spectrophotometry. Cytokine immunoassay kits were used to determine the concentration of IL‐2 and IL‐6 in the whole saliva samples. Anxiety and depression were analyzed by means of the Speilberger State‐Trait Anxiety Inventory (SAI‐TAI) and Zung Self‐Rating Depression Scale. Results: Although subjects in the control group had significantly higher mean levels for Mg compared with BMS patients (P < 0.01), no statistically significant differences were observed in relation to Zn and Cu levels between the two groups (P < 0.001). There were no statistically significant differences in IL‐2 and IL‐6 levels of BMS and control groups, but subjects in BMS group had slightly, not significantly, higher mean levels for IL‐6 compared with controls. Subjects in BMS group had significantly higher mean values for TAI compared with controls (P < 0.05). There were no statistically significant differences in relation to salivary levels of Mg, Zn, Cu, IL‐2, IL‐6 and depression/anxiety between BMS and control groups. Conclusions: The results of our study indicate that Mg levels could have an impact on symptoms of BMS and further studies are necessary to determine the importance of cytokines in the pathogenesis of BMS.     

Comparison between saliva stimulants and saliva substitutes in patients with symptoms related to dry mouth. A multi-centre study

Five saliva stimulants (Salivin, V6, Mucidan, Ascoxal-T and Nicotinamide) and three saliva substitutes (Saliment, Salisynt and an ex témpore solution) were evaluated in 106 patients with a low salivay flow rate and a long history of dry mouth. The study was carried out as a multi-centre study in collaboration with ten different hospital dental clinics. The participants were interviewed about their complaints related to dry mouth. Each patient was then asked to use the eight saliva stimulants and substitutes for 14 days in a randomized order with one week intervals. After the 14-day-periods, the patients were interviewed about the effect of the various products by a dentist using a standardized questionnaire. Paraffin-stimulated whole saliva samples were collected after each test period. The most serious complaints among the patients were, besides dryness of the mouth, difficulty to talk and difficulty to swallow. The results showed that all eight tested saliva stimulants and substitutes relieved the symptoms of dry mouth to some extent. However, V6 chewing gum and Salivin lozenge were ranked as the two best products by the patients. No long-term effect was found with any of the eight products on the flow rate of paraffin-stimulated whole saliva.     

Boundary lubrication by brushed salivary conditioning films and their degree of glycosylation

Objectives

Toothbrushing, though aimed at biofilm removal, also affects the lubricative function of adsorbed salivary conditioning films (SCFs). Different modes of brushing (manual, powered, rotary–oscillatory or sonically driven) influence the SCF in different ways. Our objectives were to compare boundary lubrication of SCFs after different modes of brushing and to explain their lubrication on the basis of their roughness, dehydrated layer thickness, and degree of glycosylation. A pilot study was performed to relate in vitro lubrication with mouthfeel in human volunteers.

Materials and methods

Coefficient of friction (COF) on 16-h-old SCFs after manual, rotary–oscillatory, and sonically driven brushing was measured using colloidal probe atomic force microscopy (AFM). AFM was also used to assess the roughness of SCFs prior to and after brushing. Dehydrated layer thicknesses and glycosylation of the SCFs were determined using X-ray photoelectron spectroscopy. Mouthfeel after manual and both modes of powered brushing were evaluated employing a split-mouth design.

Results

Compared with unbrushed and manually or sonically driven brushed SCFs, powered rotary–oscillatory brushing leads to deglycosylation of the SCF, loss of thickness, and a rougher film. Concurrently, the COF of a powered rotary–oscillatory brushed SCF increased. Volunteers reported a slightly preferred mouthfeel after sonic brushing as compared to powered rotating–oscillating brushing.

Conclusion

Deglycosylation and roughness increase the COF on SCFs.

Clinical relevance

Powered rotary–oscillatory brushing can deglycosylate a SCF, leading to a rougher film surface as compared with manual and sonic brushing, decreasing the lubricative function of the SCF. This is consistent with clinical mouthfeel evaluation after different modes of brushing.     

Analysis of residual saliva and minor salivary gland secretions in patients with dry mouth

The importance of oral mucosal wetness in the condition of dry mouth and the role of salivary proteins in proper oral function are acknowledged. A negative correlation between mucosal wetness and the protein concentration of residual saliva has been reported in normosalivators. Here, to examine the suggestion that a reduction in residual salivary volume leads to a concomitant elevation of its protein concentration, the amount of residual saliva and minor salivary gland secretions, and their protein concentrations, were measured in hyposalivators and normosalivator controls. A Periotron 8000 micro-moisture meter was used to measure the thickness of the mucosal film at six selected mucosal surfaces and the minor salivary gland secretion rate at two mucosal surfaces. The unstimulated whole salivary flow rate was measured by the spitting method. The total protein concentration of all salivary samples was measured by bicinchoninic acid assay. The hyposalivators had significantly lower amounts of residual saliva and minor salivary gland secretions than the normosalivators at all selected mucosal sites except the soft palate. In both groups, the site with the thinnest coat of residual saliva was the anterior hard palate and the wettest site was the anterior dorsal mucosa of the tongue. The protein concentration of residual saliva was significantly higher in hyposalivators than normosalivators. In the minor salivary gland secretions there was no significant difference in protein concentration between the normo- and hyposalivators. When the hyposalivators were divided into two subgroups according to their severity of dryness, the reduction of residual salivary volume and the elevation of protein concentration were more apparent in the group with the more severe dry mouth. Collectively, these results indicate that oral mucosal wetness is associated with the flow rate of unstimulated whole saliva. The function of the minor salivary glands was less affected and relatively well preserved in patients with dry mouth. The increased protein concentration of residual saliva in the hyposalivators appeared to be the result of decreased salivary volume.     

Relationships between oral MUC1 expression and salivary hormones in burning mouth syndrome

ObjectivesTo investigate possible relationships among oral mucosal epithelial MUC1 expression, salivary female gonadal hormones and stress markers, and clinical characteristics in patients with burning mouth syndrome (BMS).DesignThirty post-menopausal female patients with BMS (60.0 ± 5.0 years) were included. Clinical and psychological evaluations were performed and the expression level of oral mucosal epithelial MUC1 was analyzed. The levels of cortisol, dehydroepiandrosterone (DHEA), 17β-estradiol, progesterone, chromogranin A, and blood contamination were determined from unstimulated whole saliva (UWS) and stimulated whole saliva (SWS) samples.ResultsSalivary progesterone level had significant positive correlations with oral mucosal epithelial MUC1 expression level and with salivary cortisol and DHEA levels. The salivary level of 17β-estradiol showed significant positive correlations with period of symptom duration, severity of effects of oral complaints on daily life, and results from psychological evaluations. Cortisol level in UWS and cortisol/DHEA ratio in UWS and SWS had negative correlations with severity of oral burning sensation significantly. The severity of taste disturbance had positive correlations with results from psychometry significantly.ConclusionDysregulated psychoendocrinological interactions might affect oral mucosal MUC1 expression and severity of oral burning sensation in post-menopausal BMS patients.     

Oral condition,chemistry of saliva,and salivary levels of Streptococcus mutans in thalassemic patients

The purpose of this investigation was to determine the oral status in a group of patients with thalassemia major (TM). Eighteen TM patients (15 M, three F) and 18 healthy controls randomly matched for age and sex were examined for dental caries using the decayed, missing, and filled teeth (DMFT) index and for oral hygiene conditions using the oral hygiene index (OHI)-S. Spontaneous saliva was collected from each subject, and the biochemical composition (calcium, phosphorous, potassium, sodium, urea) was determined. Furthermore, salivary Streptococcus mutans levels were evaluated. Statistical analysis (Student's t-test) were performed for means comparison, while independence among categorical variables was assessed using the chi(2) test. Fisher's exact test was used when expected cell values were less than 5. Dental status (DMFT index) was almost equal in the two groups (10.3 in TM vs 9.4 in controls, P=0.34). The occurrence of plaque (OHI-S 2) was higher in the control group, but no statistically significant association was observed between oral hygiene conditions in the two groups (Fisher's exact test 0.47, P=0.79). Biochemical saliva composition was very similar in the two groups; only the urea concentration was lower in TM, and this difference was statistically significant ( P=0.002). The TM patients had an increased presence of mutans streptococci at detectable levels. Our findings confirm that, although no substantial differences were found between the two observed groups, further investigations are needed to determine the theoretical risk of oral diseases in thalassemic patients.     

Effect of sorbitol- and xylitol-containing chewing gum on salivary microflora, saliva, and oral sugar clearance

Abstract – The effect of frequent use of a sorbitol-containing nicotine chewing gum on saliva secretion rate and buffer capacity and some oral bacteria was studied in 27 patients at a smoking cessation clinic. The effect was compared with that obtained after frequent use of a chewing gum containing xylitol in a second study in 14 subjects. The results showed that sorbitol-containing nicotine chewing gum had no significant effect on salivary numbers of oral streptococci and lactobacilli during a 3-month period of active chewing five times a day. Chewing on xylitol-containing gum caused a significant decrease in salivary S. mutans after 2 months but not after 3 months. No change in secretion rate or buffer capacity was observed in the two studies. Oral sugar clearance time was reduced after 3 months with a statistically significant difference to baseline values in subjects consuming the sorbitol-containing nicotine chewing gum.     

Effect of sorbitol- and xylitol-containing chewing gum on salivary microflora, saliva, and oral sugar clearance

The effect of frequent use of a sorbitol-containing nicotine chewing gum on saliva secretion rate and buffer capacity and some oral bacteria was studied in 27 patients at a smoking cessation clinic. The effect was compared with that obtained after frequent use of a chewing gum containing xylitol in a second study in 14 subjects. The results showed that sorbitol-containing nicotine chewing gum had no significant effect on salivary numbers of oral streptococci and lactobacilli during a 3-month period of active chewing five times a day. Chewing on xylitol-containing gum caused a significant decrease in salivary S. mutans after 2 months but not after 3 months. No change in secretion rate or buffer capacity was observed in the two studies. Oral sugar clearance time was reduced after 3 months with a statistically significant difference to baseline values in subjects consuming the sorbitol-containing nicotine chewing gum.     

Role of saliva,salivary glands and epidermal growth factor (EGF) on oral wound healing

Saliva perform a number of biologic functions that are instrumental in maintaining oral health. Those are: lubrication, remineralization, buffering, antimicrobial protection, cleansing and maintenance of mucosal integrity. Saliva provides a natural reservoir of growth factors. By far the most highly characterized growth factor is EGF. Animal and human studies suggest that EGF plays a fundamental role in systemic and oral wound healing. This brief review is designed not to discuss all effects of EGF in detail but to highlight the basic principles of growth factors' action and their role in oral health.     

Adsorption of human salivary proteins to hydroxyapatite: a comparison between whole saliva and glandular salivary secretions.

The protein compositions of in vitro pellicles formed from whole saliva and parotid and submandibular secretions were determined by use of synthetic hydroxyapatite as a model for dental enamel. The adsorbed and unadsorbed protein fractions were analyzed by amino acid analysis and both anionic and cationic discontinuous polyacrylamide gel electrophoresis. For further characterization of the in vitro pellicle, the adsorbed fractions were subjected to gel filtration on Sephadex G-100 and reversed-phase chromatography on C18 columns. Amylase, acidic and glycosylated proline-rich proteins, statherins, and histatins were identified in the parotid-derived pellicle. Detailed analysis of the statherin-containing fractions resulted in the observation of several statherin-like proteins. The use of cationic gel electrophoresis allowed for the identification of histatin 3 and histatin 5, which have not been previously detected in pellicle formed in vitro. The protein composition of submandibular-derived pellicle was similar to that of parotid-derived pellicle except for the presence of cystatins and the absence of glycosylated proline-rich proteins. In contrast, in vitro pellicle derived from whole saliva exhibited a vastly different composition, consisting primarily of amylase, acidic proline-rich proteins, cystatins, and proteolytically-derived peptides. The results indicate that acidic phosphoproteins as well as neutral and basic histatins from pure secretions selectively adsorb to hydroxyapatite, whereas in whole saliva some of these proteins are proteolytically degraded, dramatically changing its adsorption pattern.     

The surface free energy of oral streptococci after being coated with saliva and its relation to adhesion in the mouth

Contact angle measurements on layers of bacteria were used to determine the bacterial surface free energy (gamma b) of a variety of oral streptococcal strains, both without and after being coated with human whole saliva. At least four isolates of each species, either freshly isolated or laboratory strains, were used. The species Streptococcus mutans, S. sanguis, and S. salivarius were homogeneous, having high surface free energies, and were not affected by saliva treatment (gamma b = 106 +/- 12 and 107 +/- 10 erg X cm-2 in the absence and presence of saliva coating, respectively; n = 20). S. mitis had a very low surface free energy (46 +/- 15; n = 5), which was significantly increased after salivary adsorption (71 +/- 14 erg X cm-2; p less than 0.002). The species S. milleri contained strains with both high and low gamma b. Calculation of the interfacial free energy of adhesion (delta F adh) for bacteria from a saliva suspension to solid surfaces with various arbitrary surface free energies (gamma s) showed that, theoretically, most strains will encounter thermodynamically favorable conditions for adhesion to surfaces with a gamma s above 62 erg X cm-2. However, S. mitis strains not coated with saliva would only be able to adhere to surfaces with gamma s lower than this value. Saliva-coating reverses the calculated relationship with gamma s for these strains. The results indicate that an enamel surface with a low gamma s value would be thermodynamically unfavorable for adhesion of most oral streptococci.     

Signs of oral dryness in relation to salivary flow rate,pH, buffering capacity and dry mouth complaints

Background  

This study aimed to investigate the signs of oral dryness in relation to different salivary variables and to correlate subjective complaints of oral dryness with salivary flow rate.     

The surface area of the adult human mouth and thickness of the salivary film covering the teeth and oral mucosa

The surface area of the mouth was measured to calculate the average thickness of the salivary film which separates the opposing layers of the oral mucosa and which also overlies the dental plaque. The subjects were 10 adults of each sex, all of whom had essentially a full complement of teeth. Impressions were taken of the upper and lower jaws, the buccal and labial vestibular mucosa, and the ventral surface of the tongue, and stone models were cast. The dorsum of the tongue was assumed to have the same area as the palate plus that of the palatal surfaces of the upper teeth. The six separate areas considered were the teeth, the palate, the buccal and lingual gingival and alveolar mucosa, the buccal and labial vestibular mucosa, the ventral surface of the tongue, including the floor of the mouth, and the dorsum of the tongue. Aluminum foil, of known weight per unit area, was adapted to the models of the different regions of the mouth, and the surface areas were calculated from the weights of the foil. The mean total surface area of the mouth was 214.7 +/- 12.9 cm2, and there was no significant difference due to gender. The teeth, keratinized epithelium, and non-keratinized epithelium occupied about 20%, 50%, and 30% of the total surface area, respectively. Given that the average volumes of saliva present in the mouth before and after swallowing have been estimated to be 0.77 and 1.07 mL, respectively, it can be calculated that the average thickness of the salivary film in the mouth varies between 0.07 and 0.10 mm.(ABSTRACT TRUNCATED AT 250 WORDS)