Search

Objective Chlorhexidine mouthrinses are marketed in different formulations. This study aimed at investigating qualitative and quantitative changes in in-vitro multispecies oral biofilms, induced by different chlorhexidine-containing mouthrinses. Background data Earlier studies comparing chlorhexidine mouthrinses are either clinical studies or in-vitro studies assessing the antimicrobial efficacy of the mouthrinses. However, no clear investigations are available regarding ecological impact of different chlorhexidine formulations on in-vitro multispecies oral biofilms after rinsing with different chlorhexidine formulations. Methods Nine commercially available chlorhexidine mouthrinses were selected. Multispecies oral communities (14 species) were grown for 48 h in a Biostat-B Twin bioreactor. After that, they were used to develop biofilms on the surface of hydroxyapatite disks in 24-well pates for 48 h. Biofilms were then rinsed once or multiple times with the corresponding mouthrinse. Biofilms were collected before starting the rinsing experiment and every 24 h for 3 days and vitality quantitative PCR was performed. The experiment was repeated 3 independent times on 3 different days and the results were analyzed using a linear mixed model. Results The mouthrinses provoked different effects in terms of change in total viable bacterial load (VBL), ecology, and community structure of the multispecies biofilms. There was no relation between chlorhexidine concentrations, presence, or absence of cetylpyridinium chloride and/or alcohol, and the observed effects. Some tested chlorhexidine mouthrinses (MC, HG, HH, and HI) strongly lowered the total VBL (≈1007 Geq/ml), but disrupted biofilm symbiosis (≥40% of the biofilms communities are pathobionts). On the other hand, other tested chlorhexidine mouthrinses (MD, ME, and HF) had limited impact on total VBL (≥1010 Geq/ml), but improved the biofilm ecology and community structure (≤10% of the biofilms communities are pathobionts). Conclusion Not all chlorhexidine mouthrinses have the same effect on oral biofilms. Their effect seems to be strongly product dependent and vary according to their compositions and formulations.

Quaternary ammonium compounds (QACs) comprise a large class of surfactants, consumer products, and disinfectants. The recently-isolated QAC natural product tricepyridinium bromide displays potent inhibitory activity against S. aureus but due to its unique structure, its mechanism of action remains unclear. A concise synthetic route to access tricepyridinium analogs was thus designed and four N-alkyl compounds were generated in addition to the natural product. Biological analysis of these compounds revealed that they display remarkable selectivity towards clinically-relevant Gram-positive bacteria exceeding that of commercially-available QACs such as cetylpyridinium chloride (CPC) and benzalkonium chloride (BAC) while having little to no hemolytic activity. Molecular modeling studies revealed that tricepyridinium and shorter-chain N-alkyl analogs may preferentially bind to the QacR transcription factor leading to potential activation of the QAC resistance pathway found in MRSA; however, our newly synthesized analogs are able to overcome this liability.

OBJECTIVE To compare the effectiveness of a novel cetylpyridinium chloride (CPC)-hyaluronic acid (HA)-based mouthrinse with chlorhexidine (CHX) and placebo mouthrinses in preventing plaque and gingivitis. The secondary outcomes were calculus, extrinsic stains, oral malodour and occurrence of adverse events. METHODS A 21-day randomized, double-blind, three-arm parallel study with random allocation of young dental students to any of the three mouthrinse groups. Thorough prophylaxis was done at baseline followed by a baseline examination for oral malodour, extrinsic stains, calculus, gingivitis and plaque by a single examiner. All the subjects used the allocated mouthrinse twice daily for 21 days and were examined again at the end of the experimental period. They were also interviewed for adverse events. Change in the scores of clinical indices was calculated and compared between the groups. RESULTS A total of 75 subjects were included and completed the experiment. There was a significant difference for change in plaque index scores between the groups (P = .015); subjects in the placebo group experienced higher levels of plaque accumulation than the other groups. Teeth staining increased in the CHX (P

The purpose of this study is to separate impurities from dyes using a simple separatory bottle in order to detect to allow for the characterization of these impurities using analytical separation techniques. Foaming agents were used in a glass bottle with a modified cap, to separate a target impurity using the appropriately charged ligand. By running N(2) gas through the solution, the cationic surfactant cetylpyridinium chloride (CPC) and anionic surfactant sodium dodecyl sulfate (SDS) generated foams that separated the anionic dye Orange G and cationic dye Methylene blue, respectively, from a solution containing both dyes. It was found that SDS was able to condense minute quantities of methylene blue from the solution, with high purity. CPC was also able to condense minute quantities of Orange G from the solution, however with less purity. A range of 100nmol to 50μmol of each target dye was tested. For both surfactants, the condensability was shown to increase exponentially as concentration of the target dye decreased. This novel separation method could potentially prove to be a simple, cheap, and effective way to prepare samples and identify components of impurities using HPLC, NMR, and mass spec as well as be used to purify difficult to separate charged compounds.

Objectives To compare 3 mouthwashes: 0.20% chlorhexidine (CHX) with Anti-Discoloration System (ADS), 0.20% CHX and 0.12% CHX with 0.05% cetylpyridinium chloride (CPC), in terms of reduction of plaque and gingival bleeding and side effects. Methods Mild gingivitis patients were randomly divided into three Groups: they underwent professional oral hygiene and received instructions: oral rinse with 10 mL for 1', twice a day, 30' after tooth brushing, for 14 days. Primary outcomes were plaque and gingival bleeding, assessed with Plaque Control Record and Gingival Bleeding Index. Feedback questionnaire and spectrophotometer evaluated secondary outcomes: adverse events. Timing of the study was T0 (baseline), T1 (professional oral hygiene) and T2 (14th day after mouthwash use). Results Sixty-six patients were recruited, two patients dropped out, and 64 patients completed the study. PCR T1-T2 mean variation was 30.67 (SD = 15.22; 95% CI 23.55 to 37.80; P = 0.000), 19.93 (SD = 11.03; 95% CI 14.90 to 24.95; P = 0.000) and 16.24 (SD = 15.35; 95% CI 9.60 to 22.88; P = 0.000) respectively in Groups 0.2% CHX + ADS, 0.2% CHX and 0.12% CHX + CPC. GBI mean variation (T0-T2) was -9.82 (SD = 9.27; 95% CI -5.48 to 14.16; P = 0.000), -19.31 (SD = 11.33; 95% CI -14.15 to -24.47; P = 0.000) and -21.13 (SD = 12.56; 95% CI -15.70 to -26.56; P = 0.000) respectively in Groups 0.2% CHX + ADS, 0.2% CHX and 0.12% CHX + CPC. Statistical significance was found in lower efficacy of 0.2% CHX + ADS Group. Patients tolerated 0.12% CHX + CPC mouthwash better in bleeding perception (95.5%; P = 0.046), burning sensation (13.6%; P = 0.006), and mouthwash taste (100%; P = 0.000). Results on staining were no statistically significant (P = 0.106). Conclusions Addition of CPC allows reduction of CHX percentage in mouthwash formulation while keeping equal efficacy and less side effects. ADS addition decreases CHX efficacy in reducing plaque and bleeding, while resulting more tolerated than CHX.

UMR BFP - Equipe Mollicutes; International audience; We report on the formation of surfactant-based complex catanionic coacervate droplets in mixtures of decanoic acid and cetylpyridinium chloride or cetyltrimethylammonium bromide. We show that coacervation occurs over a broad range of composition, pH, and ionic strength. The catanionic coacervates consist of elongated micelles, sequester a wide range of solutes including water-soluble organic dyes, polysaccharides, proteins, enzymes, and DNA, and can be structurally stabilized by sodium alginate or gelatin-based hydrogelation. These results suggest that catanionic coacervates could be exploited as a novel surfactant-based membrane- free protocell model.

A new method based on cetylpyridinium chloride coated ferroferric oxide/silica magnetic microspheres as an efficient solid-phase adsorbent was developed for the extraction and enrichment of ochratoxin A. The determination of ochratoxin A was obtained by high-performance liquid chromatography with fluorescence detection. In the presence of cetylpyridinium chloride, the adsorption capacity of ferroferric oxide/silica microspheres was 5.95 mg/g for ochratoxin A. The experimental parameters were optimized, including the amounts of ferroferric oxide/silica microspheres (20 mg) and cetylpyridinium chloride (0.18 mL, 0.5 mg/mL), pH value of media (9), ultrasonic time (5 min), elution solvent and volume [2(1 + 1) mL (washed twice, 1 mL each time) 1% acetic acid acetonitrile]. Under optimal experiment conditions, ochratoxin A had good linearity in the range of 2.5-250.0 ng/L in water samples with correlation coefficient of the calibration curve 0.9995. The limit of detection for ochratoxin A was 0.83 ng/L, and the recoveries were 89.8-96.8% with the relative standard deviation of 1.5-3.5% in environmental water samples. Furthermore, ferroferric oxide/silica microspheres show excellent reusability during extraction procedures for no less than six times.

Objective To compare the effect of two newly formulated chlorhexidine (CHX) and cetylpyridinium chloride (CPC) mouthrinses after scaling and root planing (SRP) in terms of clinical, microbiological, patient-based variables and adverse events, with a positive control with the same active components, already marketed and tested. Methods A pilot, randomized clinical trial, double-blind, parallel design with 1-month follow-up was conducted. Chronic periodontitis patients requiring non-surgical periodontal therapy were enrolled and randomly assigned to: (i) SRP and test-1 (new reformulation: 0.12% CHX and 0.05% CPC); (ii) SRP and test-2 (new formulation: 0.03% CHX and 0.05% CPC); or (iii) SRP and positive control (commercial product: 0.12% CHX and 0.05% CPC). All variables were evaluated at baseline and 1 month after SRP. Quantitative variables were compared by means of anova or Kruskal–Wallis test and qualitative variables by chi-square or McNemar tests. Results Thirty patients (10 per group) were included. After 1 month, there were significant differences among groups in plaque levels (P = 0.016) as test-1 showed less sites with plaque than test-2 (31.15% [standard error-SE 2.21%] versus 49.39% [SE 4.60%), respectively). No significant differences were found for global patient perception of the product or in adverse effects. Test groups showed better results in levels and proportions (P = 0.022) of Capnocytophaga spp. Conclusions Within the limitations of this pilot study, it can be concluded that the newly formulated 0.12% CHX and 0.05% CPC mouthrinse showed larger plaque level reductions, without showing more adverse effects, when compared to the other two mouthrinses, after SRP.

AIM The aim of this systematic review and network meta-analysis (NMA) was to compare the efficacy of different anti-plaque chemical agents, in 6-month, home-use, randomized clinical trials (RCTs), in terms of plaque index (PlI) changes. MATERIAL AND METHODS RCTs assessing PlI were identified, screened, and evaluated for inclusion. Relevant information was extracted, and quality and risk of bias were assessed. Mean differences between baseline-end were calculated to obtain weighted mean differences and 95% confidence intervals. NMA protocols were applied to assess direct and indirect comparisons among products using Turesky PlI. RESULTS Eighty-three papers were included: 49 examined dentifrices, 32 mouthrinses and 2 both. The NMA analysed 51 studies including data from 4242 and 4180 subjects for dentifrices and mouthrinses respectively. For dentifrices, triclosan-copolymer and chlorhexidine showed the greatest effect, with significant differences when compared with stannous fluoride. For mouthrinses, essential oils and chlorhexidine showed the greatest effect, with significant differences when compared with delmopinol, alexidine and cetylpyridinium chloride. CONCLUSION Within the limitations of this study (including the severe imbalance in the amount of evidence), dentifrices containing triclosan-copolymer or chlorhexidine and mouthrinses containing essential oils or chlorhexidine showed the greatest effect on PlI scores as assessed with NMA.

Background and Objective In the therapy of destructive periodontal disease, chemical antimicrobial agents and increasingly photodynamic therapy (PDT) play an important adjunctive role to standard mechanical anti-infective treatment procedures. However, both antiseptic methods have their shortcomings in terms of eliminating periodontal pathogens. The aim of the study was to compare the antibacterial efficacy of different antiseptic mouthrinses, of a conventional and a new, modified PDTplus as well as of the different antiseptic mouthrinses combined with either the conventional or the modified PDTplus against periopathogens. Material and Methods Six representative periodontitis-associated bacterial strains were grown for 24 h under anaerobic conditions. After mixing the individual cell pellets they were exposed to 10 different antiseptic mouthrinse formulations: chlorhexidine (0.2%, 0.06%, CHX); CHX + cetylpyridinium chloride (each 0.05%); sodium hypochlorite (0.05%); polyhexanide (0.04%, PHMB1; 0.1%, PHMB2); octenidine dihydrochloride (0.1%); fluoride (250 ppm); essential oils; povidone iodine (10%); and saline (0.9%, NaCl) as control. Furthermore, the bacteria were treated with conventional PDT based on light-emitting diodes and a new modified photodisinfection combining photosensitizer with hydrogen peroxide to PDTplus also based on light-emitting diodes. In addition to the single treatments, a combined application of antiseptic exposure followed by use of PDT or PDTplus was performed. The microbial viability was characterized by analyzing colony growth and fluorescence-based vitality proportions. Results Nearly all mouthrinses caused a statistically significant growth inhibition. The most effective antiseptics, CHX (0.2%), CHX/cetylpyridinium chloride and octenidine dihydrochloride, inhibited bacterial growth completely. Conventional PDT resulted in moderate reduction of colony growth. The modified PDTplus achieved maximum antimicrobial effect. The combination of antiseptic exposure and PDT against periopathogens predominantly increased antibacterial efficacy compared to the single applications. The mouthrinse containing essential oil seemed to interfere with PDT. Conclusion A combination therapy of preceding chemotherapeutical exposure and subsequent photodisinfection may be a more effective and promising antibacterial treatment than single applications of the antiseptic methods. The modified PDTplus using oxygen-enriched toluidine showed a superior antibacterial effect on periodontal pathogens to conventional PDT and to the majority of the investigated mouthrinses.

Aim: To evaluate the effect of different mouth rinses 12 h after rinsing on genuine intra-oral halitosis. Materials and methods: Twenty-four adults with halitosis were included in a double-blind, crossover, randomized clinical trial. Halitosis was evaluated 12 h after rinsing with placebo and five mouth rinse products containing zinc acetate and chlorhexidine diacetate; zinc lactate, chlorhexidine and cetylpyridinium chloride; zinc acetate and chlorhexidine diacetate with reduced amounts of mint and menthol; zinc chloride and essential oil; and chlorine dioxide using the organoleptic method and a gas chromatograph. Test periods were separated by 1 week. Results: Hydrogen sulphide (H2 S), methyl mercaptan (MM) and the organoleptic scores (OLS) were significantly reduced 12 h following rinsing with all substances compared to placebo (P < 0.05). H2 S was more effectively reduced after rinsing with zinc acetate and chlorhexidine diacetate and zinc acetate and chlorhexidine diacetate with reduced amounts of mint and menthol compared to rinsing with zinc chloride and essential oil (P < 0.05), and significantly lower values of MM were obtained after rinsing with zinc acetate and chlorhexidine diacetate compared to zinc lactate, chlorhexidine and cetylpyridinium chloride (P < 0.05). The percentage effectively treated individuals (H2 S (

ObjectiveTo evaluate the effectiveness of 0.07% cetylpyridinium chloride (CPC) mouth rinse for reduction of gingival inflammation and inhibition of plaque compared to a vehicle control (VC) mouth rinse over a 6-month period.Materials & MethodsParticipants (n = 62) used their randomly assigned product as adjunct to toothbrushing. Bleeding, plaque and staining scores were assessed at baseline, 3 and 6 months. Plaque and saliva samples were taken at each assessment monitoring possible shifts in the composition of the microbiota.ResultsA significant difference (P = 0.002) in favour of the CPC mouth rinse, with respect to plaque scores, was found. Bleeding scores at 6 months were not significantly different (P = 0.089). However, when correcting for baseline values, a tendency towards a significant difference in bleeding scores at end trail was observed in favour of the CPC mouth rinse (P = 0.061). Regarding staining at 3 and 6 months, a small but significant difference (8.6% and 10.4%, respectively) (P < 0.0001) was observed with lower scores for the VC group. There was a significant reduction in total anaerobic count in the CPC group at 6 months (P < 0.05). The ratio of aerobes/anaerobes was markedly increased at 3 months, especially in the CPC group. No further differences were observed between groups at 6 months.ConclusionsThe use of 0.07% CPC mouth rinse was significantly more effective in reducing plaque scores than the vehicle control. Bleeding scores were not different at 6 months. The test product was well accepted and did not cause any serious clinical side effects or negatively affected the microbiota.

This paper presents the effect of some electrolytes on the Krafft temperature (TK) of cetylpyridinium chloride in aqueous solution. The results show that more chaotropic anions raise while less chaotropic anions lower the TK of the surfactant. More chaotropic Br−, SCN− and I− form contact ion pairs with the cetylpyridinium ion and reduce the electrostatic repulsion between the surfactant molecules. As a result, these ions exhibit salting-out behavior, showing an increase in the TK of the surfactant. On the other hand, less chaotropic NO3− increase the solubility of the surfactant, with a consequent decrease in the TK. Surface tension data of the salt solutions reveal that more chaotropic ions show a relatively less molar increase in surface tension compared to less chaotropic ions. This indicates that less chaotropic ions have a preferential tendency to be negatively adsorbed at the air–water interface as well as hydrocarbon–water interface and thereby disturb the hydration of the surfactant. SO42− being a strong kosmotrope cannot form contact ion pairs with the cationic part of the surfactant. Rather this ion preferentially remains in the bulk because of its strong tendency for hydration and thereby stays apart. As a result, SO42− also causes a significant lowering of the TK of the surfactant. Thus it appears that contrary to the usual trend SO42− behave like a chaotrope showing salting-in effect of the surfactant.

A number of ruthenium catalysts, made in situ from [Ru(p-cymene)Cl-2](2) and various monodentate and bidentate phosphorus ligands were screened in the double Oppenauer oxidation of 1,6-hexanediol to caprolactone using methyl isobutyl ketone as oxidant and potassium carbonate as base. The catalyst based on 1,1-bis(diphenylphosphinyl)ferrocene gave this lactone in excellent yield. The same catalyst was evaluated for the oxidation of other diols to their lactones, of primary alcohols to the corresponding aldehydes and of secondary alcohols to the ketones under the same reaction conditions. The products were obtained in moderate to excellent yields.

Background and Objective Bacteria in the oral cavity grow in the form of biofilms; these structures are subject to constant saliva or gingival crevicular fluid flow conditions. The aims of this study were: (i) to develop and to characterize an in-vitro biofilm model with oral bacteria growing under flow and shear conditions; and (ii) to demonstrate the usefulness of the model for evaluating the activity of three antiplaque agents. Material and Methods We used a bioreactor to grow the oral bacteria Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis under planktonic conditions. Biofilms were established using a modified Robbins device on hydroxyapatite (HAP) discs. Three- to 7-d-old biofilms were analysed using culture methods, scanning electron microscopy, Live/Dead staining and fluorescence in-situ hybridization (confocal laser scanning microscopy). Finally, we assessed the antimicrobial activity of three mouthrinses [0.12% chlorhexidine (CHX), 0.12% chlorhexidine and sodium fluoride (CHX+NaF) and 0.12% chlorhexidine and 0.05% cetylpyridinium chloride (CHX+CPC)] using a planktonic test (short interval–killing test) and in our 4-d biofilm model. Results The viable cell counts showed that each species was consistently found in the biofilms throughout the study. The architecture and cell distribution were similar to those described for biofilms in situ, with the exception of a thin layer of living cells that was found close to the HAP. The effectiveness test of the mouthwashes demonstrated that cells in biofilms showed more tolerance compared with planktonic cells. Moreover, it was observed that in 4-d biofilm formed in vitro, CHX+CPC caused significantly higher mortality compared with CHX (p = 0.003) and CHX+NaF (p

We have carried out mixed micellization of pentanediyl-α,ω-bis(dimethyl cetylammonium bromide) (G5) with conventional cationic cetylpyridinium chloride (CPC) and nonionic polyoxyethylene (20) cetyl ether (C16E20) in aqueous media and explored their antimicrobial activity in single and binary systems against Escherichia coli (E.coli), Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). The compounds tested showed excellent antibacterial activity: 0.76–3.38 g/l minimum inhibitory concentration (MIC) and were more active against gram +ve bacteria. For surfactant mixtures G5-C16E20 > G5-CPC, the ionic-nonionic binary surfactant showed greater antibacterial activity. The experimental results of this study may be profitably used to understand and predict the antibacterial activity of gemini-conventional surfactant systems and provide valuable information for selection of surfactant for microbiocidal action.

Background An increased frequency of occupational contact hand dermatitis among surgical operating theatre personnel has been noticed. Objectives To evaluate patients with occupational contact dermatitis caused by their rubber gloves, and to describe a method for analysing the content of the allergens in the gloves. Materials and methods Patch tests were performed with the baseline series, a rubber chemical series, and the patients' own gloves. A method for analysing 1,3-diphenylguanidine (DPG) and cetylpyridinium chloride in the gloves was developed. Results Contact allergy to thiuram mix was found in 8 of 16 patients, whereas 12 of 16 patients reacted to DPG. In 7 of 8 patients, contact allergy to cetylpyridinium chloride was found. In the patients' gloves, cetylpyridinium chloride and DPG were detected at higher concentrations on the inside of the gloves than on the outside. Most patients had worked for decades in their present occupations, but their hand dermatitis had only been present for months. Conclusion Contact allergy to DPG in gloves has been disputed, but, in this study, we were able to confirm the presence of DPG and cetylpyridinium chloride in the causative gloves by using a modified method for the analysis. The presence of these chemicals in gloves caused an increase in occupational contact dermatitis in surgical operating theatre personnel. (Less)

Anionic and cationic surfactant mixtures exhibit desirable synergism, but are limited by their tendency to form precipitates. This research evaluates the adsorption, adsolubilization and desorption of mixtures of carboxylate-based anionic extended surfactants and a pyridinium-based cationic surfactant. The mixture of cetylpyridinium chloride (CPC), selected as the cationic surfactant, with four anionic extended surfactants were studied. The anionic surfactants studied were alkyl propoxylated ethoxylated carboxylate with average number of carbon chain length of 16 and 17 or 16 and 18 with 4 mol of propylene oxide groups and either 2 or 5 mol of ethylene oxide groups. The adsorption of anionic extended and cationic surfactant mixtures onto a negatively charged metal oxide surface (silica dioxide) was evaluated. The adsolubilization of phenylethanol, styrene and ethylcyclohexane were evaluated for these mixed surfactant systems. The desorption potential of individual and mixed surfactant systems was also evaluated by varying the number of washing (desorption) steps. It was found that the plateau adsorption of mixed anionic extended surfactant and cationic surfactant occurred at lower surfactant concentration than that of the CPC alone, although the maximum adsorption capacity of CPC was not enhanced in our mixed surfactant systems. Adsolubilization capacities of these mixed surfactant systems are higher than that of the individual surfactant system. For desorption studies, these mixed surfactant systems showed lower stability than the individual surfactant system.

We studied the cleave of bis(p-nitrophenyl) phosphate (BNPP) over a pH range of 7.0–12.0 in the presence of cationic micelles of cetyldiethylethanolammonium bromide, cetyldimethylethanolammonium bromide, cetylpyridinium bromide, cetyltrimethylammonium bromide, and cetylpyridinium chloride by using different α-nucleophiles, viz acetohydroxamate, benzohydroxamate, salicylhydroxamate, butane-2,3-dione monooximate, and α-benzoin oximate ions. With the use of α-nucleophiles in cationic micellar media, the hydrolytic cleavage of BNPP was found to be approximately 105-fold faster than its spontaneous hydrolysis. All reactions followed pseudo-first-order kinetics. The effect of various concentrations of cationic micelles for the reaction of BNPP and α-nucleophiles has been studied. The variation of kobs values of the reactions depends on the micellar structure, that is, head groups, hydrophobic tail length, and counter ion. Copyright © 2012 John Wiley & Sons, Ltd.

Purpose: This study aimed to investigate the antimicrobial properties and cytotoxicity of the monomer methacryloyloxyundecylpyridinium bromide (MUPB), an antiseptic agent capable of copolymerizing with denture base acrylic resins. Materials and Methods: The antimicrobial activity of MUPB was tested against the species Candida albicans, Candida dubliniensis, Candida glabrata, Lactobacillus casei, Staphylococcus aureus, and Streptococcus mutans. The minimum inhibitory and fungicidal/bactericidal concentrations (MIC, MFC/MBC) of MUPB were determined by serial dilutions in comparison with cetylpyridinium chloride (CPC). The cytotoxic effects of MUPB at concentrations ranging from 0.01 to 1 g/L were assessed by MTT test on L929 cells and compared with methyl methacrylate (MMA). The antimicrobial activity of copolymerized MUPB was tested by means of acrylic resin specimens containing three concentrations of the monomer (0, 0.3, 0.6% w/w). Activity was quantified by means of a disc diffusion test and a quantification of adhered planktonic cells. Statistical analysis employed the Mann-Whitney test for MIC and MFC/MBC, and ANOVA for the microbial adherence test (α= 0.05). Results: MUBP presented lower MIC values when compared with CPC, although differences were significant for C. dubliniensis and S. mutans only (p= 0.046 and 0.043, respectively). MFC/MBC values were similar for all species except C. albicans; in that case, MUPB presented significantly higher values (p= 0.046). MUPB presented higher cytotoxicity than MMA for all tested concentrations (p < 0.001) except at 0.01 g/L. Irrespective of the concentration incorporated and species, there was no inhibition halo around the specimens. The incorporation of MUPB influenced the adhesion of C. albicans only (p= 0.003), with lower CFU counts for the 0.6% group. Conclusions: It was concluded that non-polymerized MUPB has an antimicrobial capacity close to that of CPC and high cytotoxicity when compared with MMA. The antimicrobial activity of MUPB after incorporation within a denture base acrylic resin did not depend on its elution, but was shown to be restricted to C. albicans.

The construction and electrochemical response characteristics of a screen-printed electrode (SPE) for the determination of dodecyltrimethylammonium bromide (DTAB) are described. The sensor was based on the use of DTA-tetraphenylborate ion association complex as an electroactive material in screen-printed electrode with dioctylsebacate (DOS) as a solvent mediator. In aqueous solution of pH 3, the sensor displayed a stable response for six months with reproducible potential and linear response for surfactant over the concentration range 1.20 × 10(-2) -5.6 × 10(-7) mol L(-1) at 25 °C with Nernstian slope of 55.95 ± 0.58 mV decade(-1) for detection limit of 6.8 x 10(-6) mol L(-1) . The response time was 6-10 s. The selectivity coefficients indicate excellent selectivity for DTAB over many common cations (e.g. Mg(2+), Na(+), K+, Co(2+), Ni(2+), Ca(2+), Cl(-), I(-), SO(4)(-2) and cetylpyridinium chloride (CPC). The sensor was used successfully for the determining of DTAB in pure form and water samples with average recoveries of 99.98, 98.78, and 99.99%.

A new membrane electrode was prepared, using cetylpyridinium chloride based Sn(IV) phosphate (CPC-SnP) as the electroactive material. The electrode exhibits a linear response for the surfactant cetylpyridinium chloride (CPC) in the concentration range 5.0 × 10−3–5.0 × 10−6 mol dm−3 with a slope as a 29.1 mV/decade change in the concentration. The working pH range and the response time for the electrode are 2–6 and 30 s respectively. Selectivity coefficients for several cations were determined. The determination of CPC in mouth wash gave results that compare favorably with those obtained by the two phase titration method. This electrode has been utilized as an indicator electrode in the potentiometric titration of cationic surfactant CPC as well as in direct determination of CPC.

To cite this article: Int J Dent Hygiene 10, 2012; 98–106 DOI: 10.1111/j.1601-5037.2011.00523.x Rioboo M, Garcia V, Serrano J, O’Connor A, Herrera D, Sanz M. Clinical and microbiological efficacy of an antimicrobial mouth rinse containing 0.05% cetylpyridinium chloride in patients with gingivitis. Abstract: Objectives: the aim of this study was to evaluate the effects of the use of a mouth rinse and dentifrice with cetylpyridinium chloride (CPC) in patients with gingivitis. Methods: the study was designed as a 1-month, double-blind, parallel, randomized clinical trial comparing a negative control regimen (minus active ingredients dentifrice and mouth rinse) with the test products (dentifrice and mouth rinse with 0.05% CPC) in terms of plaque and gingival indexes (PI, GI), patient-based and microbiological outcome variables. The comparisons in relation to the main outcome variables (PI and GI) were made by means of the t-test, either unpaired or paired for the intergroup and intragroup comparisons, respectively. Results: no differences were detected at baseline. Both groups showed statistically significant decreases in GI (0.17–0.19), without intergroup differences. The PI demonstrated a significant decrease of −0.12 in the test group and minor changes in the negative control group (increase of +0.01). Differences between groups showed a tendency towards statistical significance. A limited impact was observed for microbiological variables in both groups. Conclusion: the results of this study show limited benefits of the evaluated formulations as adjuncts to unsupervised oral hygiene in reducing plaque accumulation, and no effect on gingivitis.

Surfactant-modified mineral surfaces can provide both a hydrophobic coating for adsorbing organic contaminants and, in the case of ionic surfactants, a charged exterior for adsorbing oppositely charged species. This research evaluates the precipitation phase boundaries and synergistic behavior of the mixtures of carboxylate-based anionic extended surfactants with a pyridinium-based cationic surfactant. One cationic surfactant (cetylpyridinium chloride) and four anionic extended surfactants were studied. The anionic surfactants studied were ethoxy carboxylate extended surfactants with average carbon chain lengths of either 16 and 17 or 16 and 18 with 4 mol of a propylene oxide group and a different number of moles of an ethylene oxide group (2 and 5 mol). Precipitation phase boundaries of mixed anionic extended surfactants and cationic surfactant were evaluated to ensure that the surface tension studies are in regions without precipitate. Surface tension measurements were conducted to evaluate the critical micelle concentration of individual and mixed surfactant systems. Precipitation phase boundaries of these novel mixed surfactant systems showed greatly reduced precipitation areas as compared to a conventional mixed surfactant system which is attributed to the presence of the ethylene oxide and propylene oxide groups and resulting steric hindrances to precipitation. Moreover, it was demonstrated that the CMC of mixed surfactant systems were much lower than that of individual surfactant systems. Synergism was evaluated in the four systems studied by the β parameter which found that all systems studied exhibited synergism. From these results, these novel mixed surfactant systems can greatly increase formulation space (reduce the precipitation region) while maintaining synergism, although slightly reduced from conventional anionic-cationic mixtures reported previously.

The critical micelle concentrations (CMC) of cetylpyridinium chloride (CPC) in water/glycerol media and in the presence of sodium chloride were determined at 25 °C by surface tension and conductance methods. Variation in CMC follows the normal trend, i.e., it increases with increases in glycerol content and decreases on adding NaCl. Empirical analysis of the exponential increase in CMC of CPC with weight per cent of glycerol is indicative of CMC having two components; one component being dependent while the other independent of the glycerol amount. The counter ion binding constant was determined from both slope–ratio and Corrin-Harkins methods and showed no dependence on glycerol amount, thus confirming the unusual trend in the behavior of β in water/glycerol media. In a water/glycerol medium, the ratio of solvent surface tension to limiting surface tension at CMC is also independent of the glycerol amount, whereas the Gordon Parameter decreases with increasing glycerol content as in other aqueous organic solvents. The air–solution interface becomes saturated by the adsorption of CPC when the concentration of added NaCl is about 0.02 mol kg−1 irrespective of the glycerol amount.

An extraction-free spectrophotometric method for the determination of cationic surfactants, such as cetylpyridinium chloride, cetyltrimethylammonium bromide and zephiramine is proposed, which is based on the formation of ternary complexes with Fe(III) and chrome azurol S. The molar ratio of the complex is 2:1:1 (Fe(III):chrome azurol S: cationic surfactant). The method is simple, rapid and sensitive, giving an apparent molar absorptivity of 4.5×104 L·mol−1-cm−1 and a linear range of 0.1–6.0 μmol/L cationic surfactants. The total cationic surfactant content can be determined directly in aqueous solutions by measuring the absorbance at 680 nm (pH 5.8). The method has been successfully applied to water samples.

Mixed micellization behavior of the dimeric cationic surfactant ethanediyl-1,2-bis(dimethyl tetradecyl ammonium bromide) with monomeric cationic surfactants cetyltrimethyl ammonium bromide (CTAB), cetylpyridinium chloride (CPC), tetradecyl dimethyl benzyl ammonium chloride (C14BCl) and cetyl dimethyl benzyl ammonium chloride (C16BCl) was studied in aqueous and aqueous polyethylene glycol (PEG) solutions at various temperatures (298.15, 308.15 and 318.15 K) using conductometric and viscometric methods. The behavior of these mixed systems was analyzed in light of Rubingh’s regular solution theory. The conductivity study indicates that the above systems behave nonideally with mutual synergism at 298.15 and 308.15 K, whereas antagonistic behavior is exhibited at 318.15 K. In the presence of PEG solution, various thermodynamic parameters associated with transfer of surfactant monomers from the medium consisting of polymer-free mixed micelles to polymer-bound mixed micelles like ∆Gto, ∆Hto and ∆Sto at various temperatures were evaluated and discussed. The viscosity study shows that in aqueous solutions all these combinations exhibit significant negative departure in the relative viscosity (ηr) from the additivity rule at 298.15 and 308.15 K, whereas at 318.15 K these combinations (except in the case of C14BCl) follow the additivity rule. In presence of 5% PEG solution, all the combinations show positive departure from the additivity rule except the combination with C14BCl which shows negative departure at all the studied temperatures.

Izutani N, Imazato S, Noiri Y, Ebisu S. Antibacterial effects of MDPB against anaerobes associated with endodontic infections. International Endodontic Journal. Abstract Aim To investigate the antibacterial effects of 12-methacryloyloxydodecylpyridinium bromide (MDPB), an antibacterial monomer synthesized by combining quaternary ammonium with a methacryloyl group, against three anaerobes associated with endodontic infections using planktonic and biofilm cells. Methodology The antibacterial activity of unpolymerized MDPB against Enterococcus faecalis, Fusobacterium nucleatum and Prevotella nigrescens was examined by agar-disc diffusion tests and determination of the minimum inhibitory/bactericidal concentrations (MIC/MBC). Rapid killing effects of MDPB against three bacteria in planktonic form were examined by a cell number counting method, and those against biofilm cells were assessed by a viability staining method. Results MDPB demonstrated inhibition against all of the bacteria tested by agar-disc diffusion tests. The MIC/MBC values of MDPB for the three anaerobes were much smaller than those of other resin monomers, although greater compared with those of cetylpyridinium chloride or chlorhexidine diacetate for E. faecalis and F. nucleatum. Significant reduction in viable planktonic cells was obtained by contact with 250 μg mL−1 of MDPB for 20 s (P

Objective: To test the plaque inhibitory effect of an experimental 0.07% cetylpyridinium chloride (CPC) mouthrinse in a 3-day plaque accumulation model in a cross-over design. Material and Methods: A total of 30 subjects (non-dental students), ≥18 years of age, were randomly assigned to use one of three different mouthrinses three times a day. After 3 days, the subjects returned for the clinical assessments and received a questionnaire to evaluate their attitude towards the product used by them. The cross-over procedure was repeated twice to have all subjects use all products. Results: A total of 29 subjects completed the protocol and this resulted in a statistically significant difference between the three groups (P < 0.001) with regard to plaque scores. Over three sessions, the mean plaque scores were 2.17 for the control product, 1.14 for the CPC group and 1.12 for the 0.1% Hexetidine product (positive control). Results of the questionnaire show that, compared with hexetidine, the taste of the CPC was appreciated better, and less oral sensations were observed following rinsing. Conclusion: The CPC mouthrinse proved to be effective in inhibiting ‘de novo’ plaque formation to an extent similar to that of a 0.1% hexetidine product. Compared with hexetidine, the taste of the CPC was appreciated better and less oral sensations were observed following rinsing.

Separation studies of four surfactants (nonionic and cationic) were performed on silica high-performance thin-layer chromatographic plates with various solvent systems. The most useful chromatographic system for the mutual separation of coexisting polyoxyethylene (20) stearyl ether (C18EO20), cetylpyridinium chloride (CPC), tetradecyl trimethyl ammonium bromide (TTAB) and polyoxyethylene (9.5), octyl phenyl ether (OPEO9.5) was formamide + 1 M formic acid (50:50 v/v). The nature of ‘H’ and ‘H+’ of formic acid (H–COO−H+) on the mobility of these surfactants was studied. The interference due to the presence of metal cations as impurities on the resolution of mixture of C18EO20, CPC, TTAB and OPEO9.5 was also examined. The limits of detection of C18EO20, CPC, TTAB and OPEO9.5 estimated were 0.0620, 0.0310, 0.0625 and 0.0312 μg/zone, respectively. The practical applicability of the proposed method was tested for the identification of four coexisting surfactants after their separation from the spiked aqueous systems.

In this work a surface tensiometric method was used to study the effect of the chain length of non-ionic surfactants, viz. ethoxylated sorbitan esters, on micellar composition, critical micellar concentration, mutual interaction parameter (β12), and activity coefficients of the mixed micelles formed with the cationic surfactant cetylpyridinium chloride at 25 °C. The micellar characteristics evaluated using the Clint, Rubingh, and Blankschtein models deviated significantly from ideality, and were used to ascertain the validity of these theories. Thermodynamic stability in terms of Maeda’s approach and interfacial properties is also discussed.

Carbon disulphide (CS2) exposure has been shown to activate the UDP glucuronosyltransferase of liver microsomes in rats pretreated with phenobarbitone. Now the nature of CS2 induced activation of the enzymes has been studied further. Phenobarbitone pretreated rats were exposed to 0.15% CS2 for 2 hrs on two successive days. The activity of UDP glucuronosyltransferase was measured from the liver microsomes after the enzymes was activated by incubation of the microsomes with various concentrations of the detergents Triton X-100, digitonin and cetylpyridinium chloride. The exposed animals showed an increased enzyme activity at all applied concentrations of the detergents; therefore in addition to membrane destruction by CS2 exposure, some other mechanism must also be involved in the CS2 induced activation of liver microsomal UDP glucuronosyltransferase. The changes in membrane lipid-protein interactions with l-anilino-8-naphthalene sulphonate (ANS) were also probed. The CS2 exposed animals had more high-affinity binding sites for ANS in their liver microsomal membranes, and in addition the quantum yield of ANS fluorescence was enhanced by CS2. The changes differed from those found after carbon tetrachloride exposure and suggest that, even if the two drugs have some common effects on microsomes, e.g. UDP glucuronosyltransferase activation, P-450 destruction and lipid peroxidation induction, the changes they cause in the microsomal micro-environment differ.

Acid mucopolysaccharides obtained from the skin of the back of mice were determined after precipitation with cetylpyridinium chloride and cellulose-column fractionation. The results are given as μmol uronic acid per gram dry fat free tissue. Following treatment with oestradiol monobenzoate the hyaluronic acid (HA) increased from 2.7 to 14.6, while the chondroitin sulphates were unaffected (3.7 to 4.2). The increase (from 1.3 to 10.8) of a fraction probably consisting of low molecular HA was considered as reflecting an intensified metabolic activity of HA in the connective tissue. A very close linear correlation (r = 0.924) was demonstrated between the increase in the high molecular HA and the increase in tissue water.

Objective: To review the literature concerning cetylpyridinium chloride (CPC) containing mouth rinses as effective adjuncts to toothbrushing in the prevention of plaque accumulation and gingival inflammation.Materials and methods: Medline and the Cochrane Central Register of Controlled Trials were searched up to January 2008 to identify appropriate studies. The primary outcome measurements were plaque accumulation and gingivitis.Results: Independent screening of titles and abstracts of 3250 papers resulted in eight publications that met the criteria of eligibility. Mean values and standard deviations were obtained by data extraction. Descriptive comparisons are presented for brushing only or brushing and rinsing. Meta-analyses were performed when possible.Conclusions: The existing evidence supports that CPC containing mouth rinses, when used as adjuncts to either supervised or unsupervised oral hygiene, provide a small but significant additional benefit in reducing plaque accumulation and gingival inflammation.

Thin layer chromatography of cationic and nonionic surfactants was performed on kieselguhr ‘G’ layers. Eight amino acids at three different concentration levels were used as aqueous mobile phase systems to examine the chromatographic behavior of cationic and nonionic surfactants. Among mobile phases used, a 0.01% methionine solution was found most suitable for the separation of cetylpyridinium chloride (CPC) from the mixture of nonionic surfactants on kieselguhr layers. The separation is not influenced by the presence of metal cations as impurities in the sample. None of the dyes, except ammonium purpurate and malachite green, hamper the separation. The exposure of the sample to UV radiation (λ = 254 nm) also does not have any adverse effect on the separation of CPC from TritonX-100 and Brij-35. The R F values of surfactants were found to vary marginally on substitution of l-methionine by its d-isomer in the mobile phase or by the change in pH of the mobile phase (0.01% l-methionine) from 2.9 to 8.8. The proposed method can also be used for preparative thin layer chromatography.

OBJECTIVES Tests have been carried out to assess the level of unsaturated disaccharide isomers obtained from chondroitin sulphate in whole saliva, which contains chondroitin sulphate derived from gingival crevicular fluid (GCF). MATERIALS AND METHODS Whole saliva was collected from periodontally diseased subjects (PDS), clinically healthy subjects (CHS) and edentulous subjects (ES). Glycosaminoglycans (GAG) were liberated by digestion with Pronase E, and precipitated with cetylpyridinium chloride and ethanol. The unsaturated disaccharides obtained by chondroitinase ACII digestion of the liberated GAG were analysed by high-performance liquid chromatography. The unsaturated disaccharides included delta Di-0S, delta Di-6S and delta Di-4S. RESULTS AND CONCLUSIONS Analysis of data indicated that delta Di-0S, delta Di-6S and delta Di-4S were found in all PDS samples. The amount (ng ml-1 collected whole saliva) of delta Di-0S, delta Di-6S and delta Di-4S (P < 0.01) indicated significant differences between CHS and PDS whole saliva samples. The quantities of delta Di-0S and delta Di-4S (P < 0.01) indicated significant differences between PDS and ES whole saliva. The amount of delta Di-0S (P < .05) and delta Di-6S (P < 0.01) also indicated significant differences between CHS and ES whole saliva. These results indicate that chondroitin sulphate in PDS and CHS whole saliva is representative of that previously reported in gingival crevicular fluid and so provides a useful and alternative means of assessing the role of GAG as indicators of periodontal disease.

SUMMARY –A method was developed to determine sodium carboxymethylcellulose (CMC) in food products containing three or more hydrocolloids after prior removal of interfering substances. Papain was used to digest the proteins; calcium chloride was added to precipitate algin and pectic acid and sulfated hydrocolloids were then precipitated by cetylpyridinium chloride (CPC) in the presence of 0.5M NaCl. Celite 535 or Hyflo Super Cel was added, the mixture filtered over Reeve angel No. 202 paper and the residue washed with 0.01% CPC-0.01M NaCl. The filtrate and washings were collected and diluted with distilled water to attain a final concentration of 0.2M NaCl at which concentration the CMC was precipitated selectively by CPC. The mixture was filtered over a Celite 535 or Hyflo Super Cel column and the residue washed with 0.5M Na2SO4 and then with 0.01% CPC-0.01M NaCl until the washings were negative to the phenol-H2SO4 reagent. Finally, the residue on the column was washed with hot 30% H2SO4 and the hydrolyzed CMC in the eluate determined by the 2,7-naphthalenediol test. Based on the amount added to mixtures, recoveries of 75–86% were obtained from milk and other highly complex and proteinaceous products, with a standard deviation of ± 0.58 mg, when 10 mg of CMC were added. The determination is critically dependent upon the degree of substitution (DS) of the CMC. As a consequence, the method cannot be applied with absolute certainty to unknown samples.