Salivary osmolality in individuals with cerebral palsy

Objective

To measure the salivary flow rate, osmolality, electrolyte and total protein concentrations in individuals with cerebral palsy (CP).

Design

Thirty-eight individuals with CP were divided according to the neuromotor abnormality type (total, spastic and dyskinectic) and compared to 22 nondisabled children (control group). Whole saliva was collected under slight suction. The salivary parameters studied were salivary flow rate, osmolality, sodium, potassium, chloride and total protein concentrations.

Results

CP individuals, with both neuromotor abnormality types (spastic and dyskinectic), presented an increase in salivary osmolality, total protein, potassium and chloride concentrations compared to the control group (p < 0.05). Moreover, a reduction in salivary flow rate was verified in spastic individuals (p < 0.05).

Conclusion

The reduction in salivary flow rate and increase in osmolality, total protein and electrolyte concentrations of saliva from cerebral palsy individuals could be caused by hypohydration status.     

The role of salivary factors in persistent oral carriage of Candida in humans

Background

Candida albicans is a commensal oral yeast in approximately one-third to one-half of the healthy population. To date, there are no studies investigating the multiple anti-candidal salivary constituents of healthy individuals with either nil or, consistent oral yeast carriage.

Objective

To compare the composition and anti-candidal activity in stimulated whole saliva of healthy ‘consistent’ oral Candida carriers with Candida-free individuals.

Methods

A sub-sample of 22 consistent, Candida-free individuals and 10 consistent Candida carriers were recruited from a 12 months screening study investigating oral Candida carriage in 97 healthy patients treated by fixed orthodontic appliances. Unstimulated and stimulated saliva samples were collected. The following salivary attributes were measured using standard methodology: the flow rate, pH, lysozyme, lactoferrin and IgA concentration and, the degree of inhibition of blastoconidial growth and blastospore germination.

Results

Saliva from the Candida-free individuals showed 20.2% higher inhibition of blastoconidial growth (p < 0.05) of a reference strain of Candida albicans. No significant differences between the other salivary attributes of the two groups were found.

Conclusion

The fact that saliva of Candida-free individuals significantly inhibited the blastoconidial growth more than Candida-carriers (p < 0.05) suggests that saliva may play a role in modulating oral candidal populations in health. Further studies, with a larger cohort are needed to confirm these findings and determine the factors that confer enhanced salivary anti-candidal activity.     

Influence of gender on the metabolism of alcohols in human saliva in vitro

Objective

The aim of this study was to investigate possible gender differences in salivary metabolism of two alcohols, ethanol and 2-propanol. Ethanol and its metabolite acetaldehyde may play important roles in tumour development, especially in the upper digestive tract. 2-Propanol is tested to elucidate our previous findings, where gender-specific differences in salivary acetone levels were seen after exposure to this alcohol.

Design

Saliva was collected from 25 females and 22 males for in vitro exposure to 2-propanol. In the experiments with ethanol, saliva samples were collected from 17 females and 18 males. The saliva was exposed in vitro to 2-propanol or ethanol. The metabolites acetone, derived from 2-propanol, and acetaldehyde, derived from ethanol, together with the maternal substance were analysed by headspace gas chromatography.

Results

No differences related to gender, age, medication or tobacco intake in the acetone concentration in the saliva samples were found. Gender, age or tobacco intake did not result in difference in the production of acetaldehyde in saliva. However, in the pre-exposure samples the men had a significantly higher concentration of acetaldehyde compared to the women (p = 0.04). Also, there was a tendency (p = 0.05) to higher concentrations of acetaldehyde in the samples (at 1 mM ethanol exposure) from subjects who take medications.

Conclusion

No gender difference in the metabolism of 2-propanol and ethanol in human saliva in vitro were found.     

Evaluation of the relationship between passive smoking and salivary electrolytes, protein, secretory IgA, sialic acid and amylase in young children

Objective

To evaluate the relationship between passive smoking as determined by salivary cotinine levels and salivary electrolytes, protein, secretory IgA, sialic acid and amylase in children.

Design

Saliva was collected from 90 passive smoker (PS) subjects (the study group) and 90 healthy age-matched children (the control group). The study group was divided into three subgroups according the number of cigarettes smoked. Socio-economic status, dental and dietary habits were recorded by questionnaire. Stimulated salivary calcium (Ca), phosphate (P), sodium (Na), potassium (P), total protein, amylase activity, sialic acid level, secretory IgA concentration and cotinine level were analysed. All data were analysed using SPSS, version 13.0.

Results

Socio-economic status, dental and dietary habits were similar between the two groups. The salivary electrolytes concentrations did not reveal significant difference between the two groups (p > 0.05). The mean cotinine levels of PS children were 1.58 ± 4.3 ng/mL. The salivary concentrations of protein were similar between the two groups (p > 0.05). The salivary secretory IgA concentration was significantly lower in the PS group than controls. The sialic acid level and amylase activity in PS group were found significantly higher compared with the controls (p < 0.05). No difference was observed for all these parameters with sex (p > 0.05). When saliva samples were analysed for output, the sialic acid level and amylase activity increased significantly in PS subjects (p < 0.05). Further, the output of secretory IgA concentration was found significantly lower compared with the controls (p < 0.05).

Conclusion

In conclusion, we show that passive smoking was associated with a decrease in secretory IgA concentration, whereas with increase in amylase activity and sialic acid level of stimulated whole saliva in young children.     

Salivary levels of IL-1β, IL-6, IL-8, and TNF-α in patients with burning mouth syndrome

Objective

To compare salivary IL-1β, IL-6, IL-8, and TNF-α levels between patients with burning mouth syndrome (BMS) and controls.

Design

Forty female patients with BMS (mean age: 61.6 ± 10.1 years) and 20 female control subjects (mean age: 65.1 ± 9.0 years) were included in the study. Unstimulated (UWS) and stimulated whole saliva samples (SWS) were collected and their flow rates were determined. Salivary IL-1β, IL-6, IL-8, and TNF-α levels and total protein concentration were also determined. Salivary transferrin level was determined to investigate the level of blood contamination in saliva samples. Gingival index of the subjects was also examined. Student's t-test, Pearson's correlation analysis, and analysis of covariance were used.

Results

No significant differences were found in the salivary levels of IL-1β, IL-6, IL-8, and TNF-α in BMS patients compared with controls. Salivary flow rates and their total protein concentrations did not differ significantly between the groups. The levels of salivary cytokines and total protein concentration correlated significantly with the level of blood contamination in both UWS and SWS.

Conclusion

There were no differences in the salivary levels of IL-1β, IL-6, IL-8, and TNF-α in BMS patients compared with controls. Cytokine levels in whole saliva were affected mainly by the amount of blood contamination.     

Identification of pro- and mature brain-derived neurotrophic factor in human saliva

Objective

Growth factors, including brain-derived neurotrophic factor (BDNF), are polypeptides that are involved in the maintenance, survival, and death of central and peripheral cells. Numerous growth factors have been identified in saliva and are thought to promote wound healing and maintenance of the oral epithelium. The aim of this study was to determine if BDNF is also found in human saliva.

Methods

Whole, unstimulated saliva samples (n = 30) were analyzed by SDS-PAGE and Western blot using an anti-human BDNF antibody. Proteolytic cleavage products were similarly assessed following the incubation of pooled saliva with N-glycanase F and plasmin. Subjects were also genotyped for the BDNF Val66Met single nucleotide polymorphism (SNP).

Results

These experiments revealed the presence of immunoreactive bands at 14, 32 and 34 kDa, corresponding to mature (mBDNF) and proBDNF, as well as a truncated pro-form at 24 kDa. Not every sample contained all forms of BDNF. Treatment with N-glycanase and plasmin reduced the size of the higher molecular weight bands, confirming the glycosylated pro-form of BDNF. mBDNF was detected significantly less often in subjects with the Val66Met SNP, compared to those without the polymorphism (χ² = 4.05; P < 0.05).

Conclusions

While the function of salivary BDNF still requires elucidation, these findings suggest that it may be possible to use saliva in lieu of blood in future studies of BDNF and the Val66Met polymorphism.     

Efficacy of natural antimicrobials in toothpaste formulations against oral biofilms in vitro

Objectives

To evaluate the antimicrobial efficacies of two toothpaste formulations containing natural antimicrobials (herbal extracts and chitosan) against oral biofilms of different composition and maturational status.

Methods

Bacteria from a buffer suspension or fresh saliva were adhered for 2 h to a salivary conditioning film and subsequently grown for 16 h. Dual-species biofilms were prepared from Actinomyces naeslundii T14V-J1 and Streptococcus oralis J22, whilst multi-species biofilms were grown from freshly collected human saliva. Biofilms were exposed to 25 wt% toothpaste supernatants. A chlorhexidine-containing mouthrinse and a buffer were used as positive- and negative-controls, respectively. Antibacterial efficacy was concluded from acute killing, bacterial removal, prevention of bacterial re-deposition and continued killing during re-deposition.

Results

The herbal- and chitosan-based supernatants showed immediate killing of oral biofilm bacteria, comparable with chlorhexidine. Moreover, exposure of a biofilm to these supernatants or chlorhexidine, yielded ongoing killing of biofilm bacteria after exposure during re-deposition of bacteria to a matured 16 h biofilm, but not to a much thinner initial biofilm formed by 2 h adhesion only. This suggests that thicker, more matured biofilms can absorb and release oral antimicrobials.

Conclusions

Supernatants based on herbal- and chitosan-based toothpastes have comparable immediate and ongoing antibacterial efficacies as chlorhexidine. Natural antimicrobials and chlorhexidine absorb in oral biofilms which contributes to their substantive action.     

The effect of sucrose on plaque and saliva urease levels in vivo

Objective

Dietary sugar exposures induce an immediate drop of the plaque pH. Based on in vitro observations, it was hypothesized that oral bacteria may rapidly respond to this environmental change by increasing the activity or expression of alkali-generating pathways, such as the urease pathway. The objective of this exploratory in vivo study was to determine the short-term effect of a brief sucrose exposure on plaque and saliva urease activity and expression, and to relate this effect to caries experience.

Methods

Urease activity levels were measured in plaque and saliva samples collected from 20 children during fasting conditions and 30 min after rinsing with a sucrose solution. Streptococcus salivarius ureC-specific mRNA in saliva was quantified using real-time RT-PCR. The impact of host-related factors, such as age, gender, sugar consumption, salivary mutans streptococci levels and caries status on urease activity was evaluated.

Results

Plaque urease activity under fasting conditions was higher in subjects with low caries and mutans streptococci levels. This difference was not observed after the sucrose exposure. The response of urease to sucrose in vivo did not depend on caries experience or salivary mutans levels. Significant increase in urease activity of plaque and saliva after exposure to sucrose was observed only in the subjects who had low urease levels at baseline.

Conclusions

The findings of this exploratory study suggest that plaque urease activity may have an important long-term influence in caries development but not during a cariogenic challenge.     

Increased calcium and decreased magnesium and citrate concentrations of submandibular/sublingual saliva in sialolithiasis

Objective

The purpose of the present study was to investigate the electrolyte alterations of submandibular/sublingual saliva in submandibular sialolithiasis patients compared with saliva from healthy controls.

Design

Submandibular/sublingual saliva was collected from 10 submandibular sialolithiasis patients and from 10 sex- and age-matched healthy controls. Ion chromatography was performed to determine the concentrations of inorganic cations (potassium, calcium, magnesium, and sodium), inorganic anions (chloride, phosphate, nitrate, and sulphate) and organic anions (thiocyanate, lactate, acetate, and citrate).

Results

The calcium concentration was significantly higher in sialolithiasis patients than in controls (P < 0.05). In contrast, the levels of magnesium and citrate in the saliva of sialolithiasis patients were significantly reduced compared to the values obtained in controls (P < 0.05). No significant differences were detected among other ions.

Conclusions

Our findings indicate that saliva electrolyte composition of sialolithiasis patients is substantially altered with respect to crystallisation mechanisms. Increased calcium ion as a crystallisation substance and decreased magnesium and citrate ions as crystallisation inhibitors may be involved in the etiopathology of calculi formation.     

Association of free amino acids with caries experience and mutans streptococci levels in whole saliva of children with early childhood caries

Objective

The aim of the present study was to identify the free amino acid content in whole saliva of children with (CE) and without early childhood caries (CF) (ECC), correlating these findings with caries experience and mutans streptococci (MS) levels in saliva.

Design

Seventy-eight healthy children, both genders, 6-71 months age, were selected to participate in the study. Following examination for dmft scores calculation, unstimulated whole saliva was collected from all 78 participants, stored at −80 °C, and used for amino acid analysis, on a Biochem 20 plus amino acid analyzer. Stimulated whole saliva was collected from 52 children, transported, diluted and plated on MSB agar medium for detection of MS in cfu/mL.

Results

Forty different free amino acids were identified in whole saliva, with great variation in their concentration. A statistically significant relation was found between caries experience and the presence of free proline and glycine. While proline (p = 0.0182) was more frequently absent in the CF group, the absence of glycine (p = 0.0397) was more often observed in the CE group. In the presence of higher levels of MS, free glycine reduced the risk of experiencing dental caries (p = 0.0419). Conversely, the presence of proline was found to increase the risk of experiencing the disease (p = 0.0492).

Conclusions

The presence of free proline and absence of free glycine in children with ECC, highly contaminated with MS, increased the chances of experiencing dental caries in the present population. Further studies are needed to better understand this phenomenon.     

Relationships of beta-blockers and anxiolytics intake and salivary secretion, masticatory performance and taste perception

Objective

Assess the influence of salivary flow on physiological parameters of the stomatognathic system in patients who take beta-blockers or anxiolytic medications.

Design

Sixty patients were divided into three groups based on the following criteria: Group 1, control (n = 20; no use of medication); Group 2, use of antihypertensive beta-blockers (n = 20); and Group 3, use of benzodiazepine anxiolytics (n = 20). Salivary flow was assessed by determining stimulated and non-stimulated flow/minute. The quantification of the sense of taste was determined on a visual analogue scale (VAS) using solutions of 0.9% NaCl (salty), 50% sucrose (sweet), 20% unsweetened coffee (bitter) and 4.2% vinegar (sour). The DMFT index (number of decayed/missing/filled teeth) was determined by a calibrated examination, following the criteria of the World Health Organization (WHO). Masticatory performance was assessed with an Optosil comminution test and Rosim-Ramler equation.

Results

The results did not reveal a significant correlation between salivary flow and masticatory performance (p > 0.05). We observed significant decreased non-stimulated salivary flow for Group 2 (p = 0.05) when compared to controls. However, taste perception was not influenced by salivary secretion amongst groups. Furthermore, we observed a significant negative correlation between non-stimulated salivary flow and DMFT in Group 1 (p = 0.02; r = −0.52).

Conclusions

Patients under beta-blockers therapy presented reduced non-stimulated salivary flow when compared to controls, without influencing the sense of taste or masticatory performance. The use of anxiolytics did not affect salivary flow and taste perception in the studied sample.     

Influence of saliva substitute films on the initial adhesion of Candida albicans to dental substrata prior to and after artificial ageing

Objective

The aim of this in vitro study was to investigate whether saliva substitute films influence the adhesion of Candida albicans to different dental substrata prior to and after artificial ageing.

Design

Specimens of a denture base resin (DB) and a veneering composite (VC) were polished and subjected to an artificial ageing protocol (thermal cycling, 2 × 3000 cycles 5/55 °C). Bovine enamel (BE) and glass were used as reference materials. After determination of surface free energy, specimens were rinsed with commercial saliva substitutes (Aldiamed, Saliva natura, Saliva Orthana, Salinum), a positive control (protein mixture), or a negative control (Phosphate Buffered Saline, PBS) for 2 h at 37 °C in a flow chamber. Specimens were then exposed to a C. albicans ATCC 10231 suspension for 4 h at 37 °C. Adherent, viable Candida cells were quantified using a luminometric ATP-based assay. Statistical analysis was performed using 1- and 2-way ANOVA, and post-hocs were analysed using the Tukey-Kramer test (α < .05).

Results

Our data indicated that VC (31.1 mJ/m²) and DB (33.9 mJ/m²) yielded the lowest surface free energy prior to artificial ageing, and BE (43.6 mJ/m²) yielded the highest surface free energy. For C. albicans adhesion, both the materials as well as the saliva substitutes influenced relative luminescence intensities, indicating significant differences in C. albicans adhesion between the various materials and after treatment with the saliva substitutes.

Conclusions

Saliva substitutes may have a decisive influence on C. albicans adhesion, but their impact appears to be dependent on the properties of the underlying substratum material.     

Salivary β-galactosidase activity affects physiological oral malodour

ObjectivesPrevious reports have associated salivary β-galactosidase activity with non-periodontopathic oral malodour. In this study, we investigated the localization of β-galactosidase and elucidated the relationship between its enzymatic activity and physiological oral malodour.Study designFifty-six patients complaining of halitosis were separated into two groups: periodontally healthy and periodontitis. Saliva samples from the subjects were separated by centrifugation, and the level of β-galactosidase activity was measured in the supernatant, pellet lysate, and whole saliva using the chromogenic substrate o-nitrophenyl-β-d-galactopyranoside. The correlation of salivary β-galactosidase activity with breath odour and associated parameters was examined.ResultsSimilar levels of β-galactosidase activity were detected in the pellet lysate and whole saliva, but not in the saliva supernatant. Positive correlations were observed between the β-galactosidase activity in whole saliva and oral malodour levels in the periodontally healthy group, but not in the periodontitis group. In addition, the plaque index and tongue coating score were positively correlated with β-galactosidase activity in the periodontally healthy group. Overall, stimulated salivary flow and salivary pH were negatively correlated with enzyme activity. The amounts of total bacteria, Fusobacterium nucleatum, and Streptococcus salivarius were positively associated with β-galactosidase activity in the periodontally healthy group. Furthermore, the amounts of total bacteria and S. salivarius were positively associated with the amount of volatile sulphur compounds.ConclusionsOur results indicate that β-galactosidase is located on the cell surface of oral bacteria derived from dental plaque and tongue coating, and it plays an important role in producing the malodour underlying physiological oral malodour.     

Effects of dentin tubule occlusion by dentifrice containing a PVM/MA bioadhesive copolymer in a silica base

Objective

To study the effectiveness of a dentifrice containing polymethyl vinyl ether-maleic acid (PVM/MA) copolymer in a silica base in occluding dentin tubules for treatment of dentin sensitivity.

Methods

Thirty-two human dentin discs were divided into two groups and brushed in the morning for 30 s each to study the dentifrices with and without PVM/MA copolymer. Dentin tubule occlusion and dentin permeability were evaluated with a focus variation three dimensional vertical scanning microscope (IFM) and electrochemical impedance spectroscopy (EIS). After second brushing for 30 s in the afternoon the dentin discs were immersed in saliva for 16 h and then subjected to erosion using orange juice for 10 min. The effects of saliva and orange juice on tubule occlusion used in the study of dentifrices were further evaluated with IFM.

Results

On average 97.7% of the dentin tubules were occluded after brushing in the PVM/MA group, as compared to 13.3% in the control group (p < 0.0001). EIS showed that the impedance of the dentin disc increased after treatment with PVM/MA but not in the control group (p < 0.05). After 16 h of storage in saliva and 10 min of erosion by orange juice, 86% of the dentin tubules remained occluded in the PVM/MA treated dentifrice. The sizes of the tubule openings were increased after orange juice erosion in the control group but not in the PVM/MA group.

Conclusion

Dentifrice containing PVM/MA copolymer in a silica base effectively occluded dentin tubules. The intra-tubular plugs were resistant to saliva and orange juice challenges.     

A universal pre-analytic solution for concurrent stabilization of salivary proteins, RNA and DNA at ambient temperature

Objective

Saliva is a biofluid that can be obtained from individuals without supervision by health care providers. To maximize this clinical advantage, it is highly desirable to have a global salivary analyte stabilizer for proteins, RNA and DNA at ambient temperature.

Design

Whole saliva, saliva supernatant and saliva filtrate (5.0 μm) were treated with RPS at room temperature (RT) for up to 6 days and then subjected to SDS-PAGE. Immunoblotting of β-actin and cystatin C were used to evaluate protein stability. For salivary DNA/RNA, whole saliva was incubated with RPS at RT for up to 10 weeks. After extracting total DNA/RNA in samples at week 0, 2, 6 and 10, DNA stability was assayed by chromosome 18 DNA qPCR and RNA stability by β-actin mRNA RT-qPCR.

Results

β-actin completely degraded in all types of saliva samples after 6-day incubation at RT. However, 24.0%, 91.4% and 89.3% of β-actin remained intact with RPS for whole saliva, saliva supernatant and filtrate, respectively. Similarly, 70.3% of cystatin C in supernatant remained intact in the presence of RPS. For salivary DNA/RNA, the cycle threshold (Ct) values showed no significant change for chromosome 18 DNA and β-actin mRNA in RPS-incubated saliva during the 10-week time course while significant increase in Ct values were observed in controls without RPS for both β-actin mRNA and DNA.

Conclusions

RPS provided effective concurrent stabilization to salivary DNA/RNA in whole saliva for up to 10 weeks and proteins in saliva filtrate for 6 days at RT. We also achieved separation of saliva supernatant from cellular elements by a simple filtration step (bypassing the need for centrifugation).     

Astaxanthin restores the enzymatic antioxidant profile in salivary gland of alloxan-induced diabetic rats

Objective

To evaluate the effect of astaxanthin on antioxidant parameters of salivary gland from diabetic rats. The hypothesis of the study was whether the supplementation of diabetic rats with astaxanthin might antagonize, or at least prevent, the defect in their antioxidative status.

Design

Wistar rats (n = 32) were divided in 4 groups: untreated control, treated control, untreated diabetic and treated diabetic rats. Astaxanthin (20 mg/kg body weight) was administered daily by gavage for 30 days. On day 23, diabetes was induced by injection of alloxan (60 mg/kg body weight). After 7 days of diabetes induction, the rats were killed and submandibular and parotid removed. Superoxide dismutase (SOD), catalase, glutathione peroxidase and reductase activities and the content of thiol groups were determined. Data were compared by ANOVA and the Tukey test (p < 0.05).

Results

Diabetes caused a reduction of SOD, and thiol content and increase of catalase and glutathione peroxidase activities of submandibular gland whilst in the parotid gland diabetes caused an increase of thiol content and no effect in the antioxidant system. The astaxanthin restores the enzymatic activities in the salivary gland, however does not prevent its oxidative damage.

Conclusion

The submandibular gland presented more susceptibility to oxidative alterations induced by diabetes. Astaxanthin presented a positive effect on the oxidative protection of the salivary gland from diabetic rats.     

Availability of saliva for the assessment of alterations in the autonomic nervous system caused by physical exercise training

Objective

The purpose of the study was to assess the alterations of the autonomic nervous system activities caused by physical exercise training under food restriction using a running wheel in mice based on an analysis of saliva.

Methods

Male ICR mice, weighing 39-50 g, at 32 weeks of age were divided into three groups; an exercise with food restriction (EXP), an exercise without food restriction (EXA) and a control (CTL). The EXP group was fed the same amount of diet as the CTL group (pair-feeding). The EXP and EXA groups used a “voluntary running wheel” for exercise. The pilocarpine stimulated whole saliva was collected from the oral cavity by micropipette over 15 min 4, 8 and 12 weeks after the beginning of the experiment. The salivary flow rate, protein concentration and amylase and kallikrein activities were determined, since amylase and kallikrein release have been shown to be evoked by β- and α-adrenergic receptor stimulation, respectively.

Results

There was no significant difference in the sera corticosterone levels among the three experimental groups. The flow rate of saliva per total salivary gland weight in the EXP was significantly lower than that in the CTL and the EXA groups. The total protein secretion and kallikrein activity decreased by 20-30% in the EXP mice between 4 and 12 weeks after the starting of experiments in comparison to the CTL mice, thus suggesting that signal transduction in the α-sympathetic nervous system was downregulated. There was no significant difference in the amylase activity between the EXP and the CTL groups.

Conclusion

Physical exercise under diet control induced alterations in saliva secretion, while exercise training alone did not affect the content of saliva. The results demonstrate the availability of saliva and suggest that the present experimental situation is a suitable experimental model for sports activity performed under diet control.     

Effect of added calcium phosphate on enamel remineralization by fluoride in a randomized controlled in situ trial

Dental products containing calcium phosphate and fluoride are claimed to enhance enamel remineralization over fluoride products.

Objectives

To compare remineralization of enamel subsurface lesions by dental products with added calcium phosphate in a double-blind, randomized, cross-over in situ study.

Methods

Human enamel specimens with subsurface lesions were prepared and inserted into intra-oral appliances worn by volunteers. A slurry (1 g product plus 4 ml H₂O) of each product was rinsed for 60 s, 4 times per day for 10 days. Six products were tested (i) placebo, (ii) 1000 ppm F, (iii) 5000 ppm F, (iv) Tooth Mousse (TM), (v) TM plus 900 ppm F (TMP) and (vi) Clinpro with 950 ppm F. Calcium, inorganic phosphate and fluoride levels were measured in post-rinse/saliva samples using ion chromatography. Mineral content was measured using transverse microradiography.

Results

Only TM and TMP significantly increased salivary calcium and phosphate levels. The products produced remineralization in the following order from lowest to highest: placebo < 1000 ppm F = Clinpro < 5000 ppm F < TM < TMP.

Conclusion

Clinpro was not significantly different to 1000 ppm F whereas TM and TMP were superior to 5000 ppm F with TMP producing the highest level of enamel lesion remineralization.     

Effect of a neutralising agent on the evaluation of the antimicrobial activity of chlorhexidine on the bacterial salivary flora

Objective

To test the efficacy of a previously described neutralising agent to counteract any antimicrobial activity of 0.2% of chlorhexidine (CHX) mouthrinse on the salivary flora, which is only exhibited after sampling of surviving bacteria, resulting in false positive efficacy data.

Methods

Unstimulated salivary samples were collected of 20 volunteers under basal conditions and at 30 s and 1 h after of a single mouthrinse of 0.2% CHX. Each salivary sample was divided into 2 equal aliquots; one was mixed with neutralising agent (3% Tween 80, 0.3% lecithin and 0.1% cysteine) and the other with a control solution. The colony forming units (cfu/mL) were determined and expressed as logarithms (log₁₀ cfu/mL).

Results

At baseline, the total bacterial concentrations were similar, independently of the addition of neutralising solution or control solution (8.419 ± 0.346 log₁₀ cfu/mL and 8.462 ± 0.474 log₁₀ cfu/mL, respectively, p = 0.440). At 30 s performing the CHX mouthrinse, the bacterial load reduction was statistically significant between both sampling methods (1.917 ± 1.275 log₁₀ cfu/mL, p < 0.001). One hour after performing the CHX mouthrinse, the bacterial load reduction was statistically significant between both sampling methods (0.537 ± 0.706 log₁₀ cfu/mL, p = 0.003).

Conclusions

Neutralising agent was not toxic to the bacterial salivary flora and effectively deactivated the “residual antimicrobial activity” of the 0.2% CHX (after exposure and during processing of samples). We propose the use of this neutralising agent when evaluating the antibacterial activity of CHX mouthrinses.