Acid production from sugars and sugar alcohols by probiotic lactobacilli and bifidobacteria in vitro.

Some probiotic bacterial strains have been suggested to improve oral health. However, lactobacilli and bifidobacteria are associated with the progression of dental caries. The pH fall caused by 14 probiotic and dairy bacterial strains from glucose, lactose, sucrose, sorbitol and xylitol was followed. All strains used glucose, nine lactose and seven sucrose. Six of the lactobacilli caused a small decrease in pH with sorbitol and two with xylitol. None of the bifidobacteria fermented sugar alcohols. As all the strains could be considered acidogenic, more long-term clinical trials are needed before recommendations for oral health purposes can be made.

Dental caries increments and related factors in children with type 1 diabetes mellitus.

The aim of this study was to analyse possible associations between caries increments and selected caries determinants in children with type 1 diabetes mellitus and their age- and sex-matched non-diabetic controls, over 2 years. A total of 63 (10-15 years old) diabetic and non-diabetic pairs were examined for dental caries, oral hygiene and salivary factors. Salivary flow rates, buffer effect, concentrations of mutans streptococci, lactobacilli, yeasts, total IgA and IgG, protein, albumin, amylase and glucose were analysed. Means of 2-year decayed/missing/filled surface (DMFS) increments were similar in diabetics and their controls. Over the study period, both unstimulated and stimulated salivary flow rates remained significantly lower in diabetic children compared to controls. No differences were observed in the counts of lactobacilli, mutans streptococci or yeast growth during follow-up, whereas salivary IgA, protein and glucose concentrations were higher in diabetics than in controls throughout the 2-year period. Multivariable linear regression analysis showed that children with higher 2-year DMFS increments were older at baseline and had higher salivary glucose concentrations than children with lower 2-year DMFS increments. Likewise, higher 2-year DMFS increments in diabetics versus controls were associated with greater increments in salivary glucose concentrations in diabetics. Higher increments in active caries lesions in diabetics versus controls were associated with greater increments of dental plaque and greater increments of salivary albumin. Our results suggest that, in addition to dental plaque as a common caries risk factor, diabetes-induced changes in salivary glucose and albumin concentrations are indicative of caries development among diabetics.

Probiotic bacteria affect the composition of salivary pellicle and streptococcal adhesion in vitro.

INTRODUCTION: The use of probiotic bacteria is increasing worldwide and at least some of them can transiently colonize the oral cavity. Several studies have shown that probiotic bacteria, which are often thought of in relation only to intestinal health, can also affect the oral ecology, but the mechanisms for this are largely unknown. The aim of this study was to investigate in vitro if the probiotic bacteria used in commercial products affect the protein composition of the salivary pellicle and the adherence of other oral bacteria. METHODS: Salivary pellicle on hydroxyapatite and the adhesion of two oral streptococci, Streptococcus mutans and Streptococcus gordonii, were used as a model. RESULTS: Probiotic bacteria that bound to saliva-coated hydroxyapatite reduced the adhesion of S. mutans but the inhibitory effect on the adherence of S. gordonii was weaker. Salivary pellicle protein composition was modified by all the strains tested. The modifications in the pellicle affected the adherence of S. mutans but not of S. gordonii. Two of the proteins missing from the pellicles made of saliva-treated with the probiotic bacteria were identified as salivary agglutinin gp340 and salivary peroxidase. All bacterial strains bound salivary agglutinin gp340. The ability of the probiotic bacteria to degrade peroxidase was demonstrated with purified bovine lactoperoxidase and two of the probiotic strains. CONCLUSION: This in vitro study showed that probiotic strains used in commercial products may affect the oral ecology by specifically preventing the adherence of other bacteria and by modifying the protein composition of the salivary pellicle.

Conclusiones del Simposium 2007 de la Sociedad Española de Medicina Oral sobre “Xerostomía. Síndrome de Boca Seca. Boca Ardiente” / Conclusions of 2007 Simposium by the Spanish Society of Oral Medicine; on "Xerostomia. Dry Mouth Syndrome. Burning Mouth"

No disponible

No disponible

Oral adhesion and survival of probiotic and other lactobacilli and bifidobacteria in vitro.

INTRODUCTION: Most probiotic products are consumed orally and hence it is feasible that the bacteria in these products may also attach to oral surfaces; however, the effects of these bacteria on the oral ecosystem are mostly unknown. Our aim was to evaluate the oral colonization potential of different probiotic, dairy, and fecal Lactobacillus and Bifidobacterium strains in vitro. METHODS: The binding of 17 Lactobacillus and seven Bifidobacterium strains to hydroxyapatite and microtitre wells coated with human saliva was tested. Binding of selected strains to human buccal epithelial cells and co-adherence with Fusobacterium nucleatum were also investigated. In addition, the survival in sterilized human whole saliva was examined. RESULTS: There was a large variation in binding to saliva-coated surfaces and buccal epithelial cells but all strains survived in saliva. The binding pattern of the probiotics did not differ from the binding of the fecal strains. F. nucleatum altered the binding of both the low-binding bifidobacteria and the high-binding lactobacilli. CONCLUSION: The differences in binding in vitro may indicate that there are also differences in the persistence of the different probiotic strains in the oral cavity in vivo.

Effects of anaesthesia using endotracheal intubation or the laryngeal mask airway, or spinal anaesthesia, on oral mucosal host defences during minor surgery.

BACKGROUND: Oral mucosal host defences are altered after anaesthesia and surgery. The effects of endotracheal intubation (ET) and the use of the laryngeal mask airway (LMA) on oral mucosal host defences after minor surgery were compared. METHODS: Immunological (immunoglobulin A (IgA), IgG and IgM) and non-immunological (myeloperoxidase, total peroxidase, thiocyanate) oral host defence factors, and amylase and protein concentrations, were measured from saliva pre-operatively and on the first post-operative day in 60 ASA I-II patients undergoing minor surgery. The patients underwent general anaesthesia using oral ET or LMA. Spinal anaesthesia (S) was used as control. Serum IgG, IgM and IgA concentrations were determined. RESULTS: Protein-related salivary secretion of amylase and salivary concentration of IgM showed the only statistically significant overall differences between the groups. By contrast, changes were observed within the ET group in the salivary flow rate, protein concentration, amylase activity and immunological host defence factors. Some changes were also observed in the LMA group, but none in the S group. Most non-immunological test values did not change within any of the groups. CONCLUSIONS: ET and LMA induced similar oral mucosal host defence responses. There were, however, observations in this study that indicated a stronger response during ET than when LMA was used.

Effects of homeopathic treatment on salivary flow rate and subjective symptoms in patients with oral dryness: a randomized trial.

Twenty-eight patients with xerostomia participated in a blind, placebo-controlled longitudinal study of the possible effects of homeopathic medicines on oral discomfort. All patients were first divided in two groups according to their medication. After that the two groups were randomly assigned according to a coin-toss to the experimental or control group. Most patients had systemic diseases, such as rheumatoid arthritis and/or Sjögren's syndrome, and frequent daily medications. The randomly selected experimental group (n=15) got an individually prescribed homeopathic medicine and the control group (n=13) a placebo substance (sugar granules), both for 6 weeks. Neither group knew of the nature of the medicine. Oral dryness was evaluated by measurement of unstimulated and wax-stimulated salivary flow rates and visual analogue scale. With only two exceptions, the experimental group experienced a significant relief of xerostomia whereas no such effect was found in the placebo group. Stimulated salivary flow rate was slightly higher with homeopathy than placebo but no consistent changes occurred in salivary immunoglobulin (IgA, IgG) levels. In an open follow-up period those receiving homeopathic medicine continued treatment and the placebo group patients were treated with individually prescribed homeopathic medicines. The symptoms of xerostomia improved in both groups. Our results suggest that individually prescribed homeopathic medicine could be a valuable adjunct to the treatment of oral discomfort and xerostomic symptoms.

Determination of safety levels of horseradish peroxidase-iodide system to human gingival keratinocytes and fibroblasts in vitro.

The peroxidase-iodide (I-) system is a potential antimicrobial agent, and its bacteriocidal activity against various periodontal bacteria has been shown in many studies. The aim of this study was to investigate the possible cytotoxic effects of a non-physiological horseradish peroxidase (HRP)-I- system on human gingival keratinocytes and fibroblasts. Immortalized human skin keratinocyte cell line was used as a reference. Three indicators were studied: membrane permeability (trypan blue staining), cell growth (crystal violet staining) and metabolic activity (alamarBlue stain). The cells were cultured in microtitration plates, and the most commonly used exposure time to the HRP system was 1 h. The effects of HRP system on cell growth and metabolic activity were observed at lower I- and H2O2 concentrations than its effects on membrane permeability. Gingival fibroblasts were more prone to detachment than keratinocyte cell lines, but no differences in changes of growth or metabolic activities were observed between gingival fibroblasts and gingival keratinocytes. The highest concentrations of the HRP-I- system components which did not have any significant detrimental effects on the metabolic activity and cell growth of gingival keratinocytes and fibroblasts were: 50 microg/ml HRP, 500 micromol/L I- and 500 micromol/L H2O2. Although this system has been shown to be antibacterial against oral bacteria, no recommendations about the usage of the HRP-I- system in oral cavity can be made yet due to the in vitro nature of this study. Our results form the basis for future safety studies investigating the chronic toxicity of this system to oral epithelium.

Salivary defense factors in herpes simplex virus infection.

Saliva may contribute to a lowering of the infectious herpes simplex virus (HSV) dose during transmission and consequently abrogate infection or lead to decreased reactivation. To test this hypothesis, we assayed saliva for innate defense factors, immunoglobulin content, and the capacity to interfere with HSV infection. Serum or salivary anti-HSV IgG levels did not correlate with control of recurrent labial herpes (RLH) and were significantly higher in subjects with RLH compared with asymptomatic seropositive subjects. Although no differences in levels or output rate of innate defense factors between the groups were observed, the salivary neutralizing activity correlated with lactoferrin and hypothiocyanite concentrations in the asymptomatic seropositive group. Our results suggest that saliva contains factors, in addition to anti-HSV immunoglobulins, that neutralize HSV and may indirectly contribute to the control of RLH.

Lactoperoxidase inhibits glucosyltransferases from Streptococcus mutans in vitro.

This study examines the possible effect of the antimicrobial peroxidase system on the activity of streptococcal glucosyltransferases B, C and D (GtfB, GtfC and GtfD), either in solution (GtfB and GtfC) or when adsorbed to hydroxyapatite (GtfC and GtfD) at pH 6.5. The lactoperoxidase (LP) system (LP, H(2)O(2), SCN(-)) had no effect on the activity of dissolved GtfC, but the activity of dissolved GtfB was enhanced. The LP system, however, strongly inhibited the activities of both GtfC and GtfD in their adsorbed form. LP enzyme, without its substrates, inhibited all three Gtf enzymes: GtfB and GtfC in concentrations between 10 and 100 microg/ml in liquid phase and adsorbed GtfC and GtfD in concentrations between 25 and 50 microg/ml. This inhibition was in part abolished in liquid phase, but not in solid phase, if the substrates of LP were added. This study shows that the lactoperoxidase system can exert inhibitory activity against streptococcal Gtfs without generating oxidizing agents.

Clinical applications of antimicrobial host proteins lactoperoxidase, lysozyme and lactoferrin in xerostomia: efficacy and safety.

Innate human salivary defence proteins, lysozyme, lactoferrin and peroxidase, are known to exert a wide antimicrobial activity against a number of bacterial, viral and fungal pathogens in vitro. Therefore, these proteins, alone or in combinations, have been incorporated as preservatives in foods and pharmaceuticals as well as in oral health care products to restore salivas' own antimicrobial capacity in patients with dry mouth. These antimicrobials used in oral health care products, such as dentifrices, mouth-rinses, moisturizing gels and chewing gums, have been purified from bovine colostrum. In this review I critically evaluate the clinical efficacy and safety of this kind of preventive approach against various oral diseases and symptoms.

Dental amalgam fillings and the amount of organic mercury in human saliva.

We studied differences in the amounts of organic and inorganic mercury in saliva samples between amalgam and nonamalgam human study groups. The amount of organic and inorganic mercury in whole saliva was measured in 187 adult study subjects. The mercury contents were determined by cold-vapor atomic absorption spectrometry. The amount of organic and inorganic mercury in paraffin-stimulated saliva was significantly higher (p<0.001) in subjects with dental amalgam fillings (n = 88) compared to the nonamalgam study groups (n = 43 and n = 56): log(e) (organic mercury) was linearly related to log(e) (inorganic mercury, r(2) = 0.52). Spearman correlation coefficients of inorganic and organic mercury concentrations with the number of amalgam-filled tooth surfaces were 0.46 and 0.27, respectively. Our results are compatible with the hypothesis that amalgam fillings may be a continuous source of organic mercury, which is more toxic than inorganic mercury, and almost completely absorbed by the human intestine.

Influence of maternal xylitol consumption on mother-child transmission of mutans streptococci: 6-year follow-up.

Xylitol is effective as a noncariogenic or even cariostatic sugar substitute. Habitual xylitol consumption appears to select for mutans streptococci (MS) which shed easily into saliva from plaque. We have earlier shown that habitual xylitol consumption of mothers was associated with a statistically significant reduction in the probability of mother-child transmission of MS assessed at 2 years of age. The aim of the present study was to assess the children's MS counts 1 and 4 years after the maternal xylitol consumption had been discontinued. At baseline, during pregnancy, all mothers (n = 195) showed high salivary levels of MS. The mothers were randomly assigned to xylitol, fluoride (F) and chlorhexidine (CHX) groups. In the xylitol group, the mothers chewed xylitol-sweetened gum, for 21 months, starting 3 months after delivery. In the two control groups, the mothers received CHX or F varnish treatments at 6, 12 and 18 months after delivery. At the 2-year examination, 169 mother-child pairs participated. At the 3-year and 6-year examinations, there were 159 and 147 children in the study, respectively. For children's MS analyses, visible plaque was collected using toothpicks at the age of 3 and paraffin-stimulated saliva at the age of 6. The persons involved in the collection and analysis of the microbiological samples were blinded as to the study design and group. Both the plaque and salivary MS were cultured on Mitis salivarius agars containing bacitracin. In all groups, the colonization percentages increased during the follow-up. At the 3-year examination, the children's risk of having MS colonization was 2.3-fold in the F group (95% CI 1.3-4.2) compared to the xylitol group. This difference was statistically significant. Even at 6 years of age, the salivary MS levels were significantly lower in the xylitol group than in the other groups (ANOVA, p<0.001). In conclusion, the earlier demonstrated, xylitol-associated reduction in the probability of mother-child transmission of MS was still found in the children's MS counts at the age of 3 and 6 years.

The effects of glycopyrrolate on oral mucous host defenses in healthy volunteers.

UNLABELLED: We studied the effects of glycopyrrolate on oral mucous host defenses. Single IV doses of glycopyrrolate (4 microg/kg) or placebo were administered to 12 healthy volunteers in a randomized, double-blinded, cross-over study. Salivary flow rates and the concentrations/activities of total protein, amylase, and nonimmunologic (lysozyme, lactoferrin, myeloperoxidase, total salivary peroxidase, and thiocyanate) and immunologic (total immunoglobulin A, immunoglobulin G, and immunoglobulin M) mucous host defense factors were determined for paraffin-stimulated whole saliva before and 1, 3, 6, 12, 24, and 48 h after drug administration. Glycopyrrolate serum concentrations were determined before and 2, 4, 6, 10, 15, and 30 min and 1, 2, 3, 6, 12, and 24 h after IV drug injection. Salivary flow rates were decreased significantly for 12 h after glycopyrrolate injection, compared with saline injection. The concentrations of immunologic and nonimmunologic defense factors were increased in the glycopyrrolate group, and differences between the groups were found for all factors (P < 0.05-0.001) except lysozyme and total salivary peroxidase. In contrast, because of the reduced flow rate, the output of all defense factors into the saliva was decreased after glycopyrrolate injection, compared with saline injection. Glycopyrrolate thus decreases the output of salivary host defense factors into the oral cavity. IMPLICATIONS: Glycopyrrolate induces long-lasting hyposalivation and decreases the secretion of salivary immunologic and nonimmunologic defense factors in healthy volunteers.

Influence of maternal xylitol consumption on acquisition of mutans streptococci by infants.

Xylitol is effective as a non-cariogenic sugar substitute. Habitual xylitol consumption appears to select for mutans streptococci (MS) with impaired adhesion properties, i.e., they shed easily to saliva from plaque. One hundred sixty-nine mother-child pairs participated in a two-year study exploring whether the mothers' xylitol consumption could be used to prevent mother-child transmission of mutans streptococci. All mothers showed high salivary levels of mutans streptococci during pregnancy. The mothers in the xylitol group (n = 106) were requested to chew xylitol-sweetened gum (65% w/w) at least 2 or 3 times a day, starting three months after delivery. In the two control groups, the mothers received either chlorhexidine (n = 30) or fluoride (n = 33) varnish treatments at 6, 12, and 18 months after delivery. The children did not chew gum or receive varnish treatments. MS were assessed from the mothers' saliva at half-year intervals and from the children's plaque at the one- and two-year examinations. The MS were cultured on Mitis salivarius agars containing bacitracin. The salivary MS levels of the mothers remained high and not significantly different among the three study groups throughout the study. At two years of age, 9.7% of the children in the xylitol, 28.6% in the chlorhexidine, and 48.5% in the fluoride varnish group showed a detectable level of MS. In conclusion, therefore, habitual xylitol consumption by mothers was associated with a statistically significant reduction of the probability of mother-child transmission of MS assessed at two years of age. The effect was superior to that obtained with either chlorhexidine or fluoride varnish treatments performed as single applications at six-month intervals.

Resistance to mercury and antimicrobial agents in Streptococcus mutans isolates from human subjects in relation to exposure to dental amalgam fillings.

Resistance to cefuroxime, penicillin, tetracycline, and mercury is reported for 839 Streptococcus mutans isolates from 209 human study subjects. The MICs of these drugs did not differ for isolates from one dental amalgam group and two nonamalgam subsets: a group with no known exposure to amalgam and a group whose members had their amalgam fillings removed.

Efficacy of a slow-release device containing fluoride, xylitol and sorbitol in preventing infant caries.

A novel slow-release administration device, the "Fall-Asleep Pacifier" (FAP), was studied as a prophylactic measure against mutans streptococcal oral infection and dental caries in a risk group of 1-year-old children by comparing the test (T, n = 34) and control (C, n = 88) groups in a prospective cohort study. In the T group the children received their fluoride tablets (Fludent, containing NaF corresp. 0.25 mg F0- , xylitol 159 mg and sorbitol 153 mg) in the evenings in FAP. In the C group the children received the same dose of Fludent crushed in food in the evenings. The proportion of children, whose plaque samples from the upper incisors were mutans streptococcus positive at the age of 24 months, was significantly (P < 0.05) greater in group C (25%) than in group T (9%). The children in the T group developed significantly (P < 0.001) less (none) new dentinal carious lesions in their primary dentitions than the children in the C group between 2 and 3 1/2 years of age. Fifty-four percent of the children to whom the FAP was offered complied with regular use of it. The beneficial effect observed in the T group compared with the C group was apparently mostly due to the administration mode via FAP, which could prolong the intra-oral bioavailability of the prophylactic preparation.

Non-immunoglobulin defense factors in canine saliva and effects of a tooth gel containing antibacterial enzymes.

Selected innate: non-immunoglobulin defense factors in canine saliva were characterized and quantitated. The samples from dogs showed increased pH, higher lysozyme and salivary peroxidase activities, but lower hypothiocyanite concentration and myeloperoxidase activity when compared with human saliva. Secondly, a 1-month clinical pilot study was performed using a commercial tooth gel to determine acute and long-term changes in salivary host defense proteins. Daily application of the tooth gel did not substantially affect the concentrations of these factors in dogs with normal salivation. Our results suggest that canine saliva may be similar to human saliva, comprised of both immune and non-immune antimicrobial factors. However, as in humans, oral administration of antimicrobial proteins as reported here does not seem to benefit dogs with normal saliva secretion. Products such as the tooth gel evaluated in this study may benefit dogs with xerostomia or other clinical conditions causing decreased saliva production.

Colostral proteins from cows immunised with Streptococcus mutans/S. sobrinus support the phagocytosis and killing of mutans streptococci by human leucocytes.

Passive immunisation, based on bovine colostral preparations, is an area of active research. Specific bovine antibodies inhibit the virulence factors of target pathogens but the interactions between whey preparations and human immune defence cells are not well known. Bovine colostrum inhibits the phagocytic activity of bovine leucocytes and this may reflect the biological activity of immunoglobulins in it. Therefore, this study aimed to examine the effects of bovine whey protein preparations from the colostrum of Streptococcus mutans/S. sobrinus-immunised and sham-immunised cows on binding, ingestion and killing of these bacteria by human leucocytes. Binding and ingestion of FITC-labelled bacteria were estimated by flow cytometry and leukocyte activation was measured as chemiluminescence. Killing rate was estimated by plate counting and by measuring bioluminescence from S. mutans- containing the insect luciferase gene. Colostral whey protein preparation from hyperimmunised cows activated human leucocytes by opsonising specific bacteria. Neutrophils, eosinophils and monocytes weakly phagocytosed non-opsonised bacteria and bacteria opsonised with control product. On the contrary, binding and ingestion were efficient in the presence of the preparation from immunised cows. Thus, these results show that bovine colostral whey proteins are able to support the activation of human phagocytes against pathogenic microbes and that this property is related to specific antibodies in whey preparations. These whey proteins may also be clinically useful, especially in preventing the colonisation of newly erupted teeth by mutans streptococci.