Short- and Long-Term Effects of a Dentifrice Containing Dual Zinc plus Arginine on Intra-Oral Halitosis: Improvements in Breath Quality.

OBJECTIVES: These studies aimed to assess the short-term (12-hour, single use) and long-term (four weeks, continuous use) efficacy of a new Dual Zinc plus Arginine dentifrice against intra-oral halitosis versus a negative control. METHODS: Two clinical studies were conducted to assess the dentifrice: a four-week, continuous use parallel design versus a negative control and a single use crossover design versus a negative control. Both studies used organoleptic and hedonic odor judge scores measured 12 hours overnight after product use as the primary efficacy variable. Additionally, the single use study employed SIFT-MS to quantify the intra-oral concentration of volatile sulfur compounds as a complementary measure of efficacy. RESULTS: In both studies, the Dual Zinc plus Arginine dentifrice provided statistically significant improvements in breath quality across all measures versus a negative control. CONCLUSIONS: Improvements in breath quality were attributed to the effects of zinc cations delivered by the uniquely formulated dentifrice.

Noninvasive measurement of reepithelialization and microvascularity of suction-blister wounds with benchmarking to histology.

We explored use of the suction-blister wound model in the assessment of not only epidermal regeneration but also pain, the microvascular response and bacteriology. The effects of topical zinc sulfate were studied to articulate the methodologies in this double-blind trial. One epidermal suction blister (10 mm) was induced on each buttock in 30 healthy volunteers (15 females:15 males) and deroofed on day 0. The wounds were randomized to daily treatment with 1.4% zinc sulfate shower gel (n = 20), placebo (n = 20) or control (n = 20). Digital photography coupled with planimetry, transepidermal water loss (TEWL) measurement and optical coherence tomography (OCT) was benchmarked to the gold standard of histology of 60 full-thickness wound biopsies on day 4. Pain increased after application of the shower gels. Microvessel density, determined from OCT images, increased from day 0 to day 2 in the three groups but increased more with the placebo than with the zinc shower gel (p = 0.003) or the control treatment (p = 0.002) and correlated (rS = 0.313, p = 0.015) with the inflammatory response on day 4, as determined by histology. Coagulase-negative staphylococci were more common in wounds compared with skin (p = 0.002) and was reduced (p = 0.030) with zinc sulfate treatment. Planimetric analysis of digital wound images was not biased (p = 0.234) compared with histology, and TEWL measurements showed no correlation (rS = 0.052, p = 0.691) with epithelialization. Neoepidermal formation, determined by histology, did not differ (p = 0.290) among the groups. Zinc sulfate reduced (p = 0.031) the release of lactate dehydrogenase from cultured gel-treated keratinocytes isolated from the blister roofs. Therefore, combination of the standardized suction-blister wound model with noninvasive planimetry and OCT is a useful tool for assessing wound therapies. Zinc sulfate transiently dampened inflammation and reduced bacterial growth.

A Comparative Study of Laboratory Dentifrice Abrasion Measuring Methods.

OBJECTIVES: Recently, a profilometry-based method for measuring toothpaste dentin abrasivity has been proposed to be equivalent to the traditional radiotracer RDA (relative dentin abrasion) procedure. This review outlines the findings and comparative assessment of laboratory studies used to measure the abrasivity of commercially available whitening dentifrices on human dentin. Traditional radiotracer and profilometry RDA-PE (Profilometry Equivalent) methods were assessed, with the objective of determining how they compare, and also to learn if the two techniques yield RDA values that are consistent with each other, specifically in ranking and potential for discrimination of three commercially available silica-based products. Chosen were regular toothpaste and two whitening dentifrices having abrasive properties against dentin ranging from medium to high. METHODS: Dentin specimens underwent standard preparation, preconditioning, and abrasivity testing according to the ISO 11609 requirements for radiotracer method and RDA-PE. Three test dentifrices were used, each product containing various abrasive and polyphosphate agents, namely: Whitening Product A: Hydrated silica with disodium pyrophosphate (Crest® 3D Luxe); Product B: Hydrated silica (Crest® Cavity Protection); and Whitening Product C: Hydrated silica with tetrasodium pyrophosphate (Colgate® Ultrabrite Advanced Whitening). The products were chosen since they gave a range of RDA values from mid to high when compared with an ADA reference material that is given a value of 100. RESULTS: The data were subjected to statistical and SNK (Student-Newman-Keuls) analyses. Both procedures yielded numerical RDA values that permitted a ranking of the three test dentifrices. However, there was no direct correlation of the RDA values obtained by profilometry with those from the conventional radiotracer method. Significantly, one dentifrice rated as most abrasive using the radiotracer method was rated as moderately abrasive using profilometry. Additionally, there was loss of statistical significance and discrimination between products with RDA-PE. CONCLUSIONS: Given the lack of agreement between radiotracer and profilometry for the products tested in this study,it would appear that the RDA-PE method may not be equivalent to the traditional RDA radiotracer method, specifically in the higher abrasivity range.

A 12-week clinical study assessing the clinical effects on plaque metabolism of a dentifrice containing 1.5% arginine, an insoluble calcium compound and 1,450 ppm fluoride.

PURPOSE: To evaluate the clinical effect on plaque metabolism of a dentifrice containing 1.5% arginine, an insoluble calcium compound and 1,450 ppm fluoride compared to a commercially available dentifrice containing 1,450 ppm fluoride in a silica base. METHODS: A 12-week, parallel, randomized, double-blind study using 48 subjects was conducted at the Colgate-Palmolive Technology Center (Piscataway, NJ, USA). One group used a test dentifrice containing 1.5% arginine, an insoluble calcium compound and 1,450 ppm fluoride as sodium monofluorophosphate (MFP), and the other group used a commercial silica dentifrice with 1,450 ppm fluoride as sodium fluoride (NaF) as a control. Plaque metabolism analyses were conducted at baseline and after 2, 4, 6, 8, and 12 weeks of assigned product use. The plaque analyses included pH measurements before and after a sucrose rinse, ammonia production and lactic acid production. RESULTS: Subjects using the test dentifrice had significantly higher plaque pH values before (P< or = 0.01) and after (P< or = 0.045) a sucrose challenge than those using the commercially available control dentifrice. Subjects using the test dentifrice also produced higher levels of ammonia and lower levels of lactic acid compared to subjects using the control dentifrice.

Pilot clinical study to evaluate the efficacy of a professionally delivered high fluoride varnish on erosive tooth wear in an in-situ model.

OBJECTIVES: The aim for this pilot study was to investigate the effect of a sodium fluoride varnish on step height measured by a profilometer from human enamel worn by healthy volunteers with a novel in situ/ex vivo erosion design. METHOD: Healthy volunteers aged 18-70 years wore a palatal splint containing 8 human enamel samples and underwent two 3-day treatment periods for 6 h a day with a varnish containing sodium fluoride at 22,600 ppm and the control with the same ingredients but without fluoride. Each splint contained 4 polished and 4 unpolished samples. The interventions were applied to the surface of the enamel samples in randomised order, removed after 6 h, then immersed ex-vivo in 1 %, pH 2.7 citric acid for 2 min, repeated 4 times a day, over 2 days. Measurements of enamel were assessed blindly by microhardness on day 2 and by non-contact laser profilometry on day 3 for the two treatments. RESULTS: 24 volunteers, 2 males and 22 females aged 27-54 years, were screened and recruited. The delta microhardness, from polished samples removed at the end of day 2, for the control and fluoride treatment was 95.7 (22.9) kgf/mm2 and 123.7 (28.9) kgf/mm2, respectively (p < .005). The mean (SD) step height for the control polished enamel surfaces was 3.67 (2.07) µm and for the fluoride varnish was 1.79 (1.01) µm (p < .0005). The control unpolished enamel surfaces had a mean 2.09 (1.53) µm and the fluoride varnish was 2.11 (1.53) µm but no statistical difference was detected. CONCLUSIONS: The results from this pilot study, utilizing an in-situ model where enamel was exposed to acid over the course of 2 days, demonstrated that a high fluoride varnish containing sodium fluoride at 22,600 ppm prevented erosive wear compared to a control on the polished enamel surfaces. CLINICAL SIGNIFICANCE: Intra-oral study demonstrated that a high fluoride varnish containing sodium fluoride at 22,600 ppm reduced erosive tooth wear.

In vitro antibacterial efficacy of cetylpyridinium chloride-containing mouthwashes.

OBJECTIVE: The objective of this study was to examine the ability of three CPC-containing mouthwashes to kill planktonic bacteria in an in vitro short-exposure assay. METHODS: This blind study was conducted on two common oral bacterial species: Aggregatibacter (Actinobacillus) actinomycetemcomitans and Streptococcus mutans. The following mouthwashes were tested: two containing 0.075% CPC and 0.05% NaF in an alcohol-free base, and one containing 0.075% CPC and 0.05% NaF plus 6% alcohol. Additionally, a 0.05% NaF-only mouthwash was included as a negative control. Bacteria were exposed to one of the test mouthwashes for 30 seconds and then washed thoroughly, serially diluted, and plated on appropriate media to determine viable bacterial counts. Viable counts were converted to a log reduction in colony forming units (CFUs) relative to the negative control. RESULTS: All three test mouthwashes included in this study gave a statistically significant reduction of > 3 log CFUs relative to samples treated with the negative control. CONCLUSION: All three experimental 0.075% CPC mouthwash formulas gave a > 99.9% reduction in viable bacteria of both species following 30 seconds of treatment.

Comparing the effects of brushing with a new gel-to-foam dentifrice to brushing with regular fluoride control dentifrices on viable bacteria levels in saliva.

PURPOSE: To compare the effects of a new gel-to-foam dentifrice to two standard fluoride control dentifrices on foam generation, levels of total viable anaerobes and total viable volatile sulfur compound (VSC)-producing bacteria in expectorate after brushing. METHODS: 36 subjects participated in this investigator-blind, randomized, crossover study. After a 1-week wash-out period prior to each product use, participants reported to the test site having refrained from oral hygiene, eating and drinking on the morning prior to the visit. Subjects brushed with a full ribbon of assigned dentifrice (Aquafresh Iso-active, Aquafresh Extreme Clean or Aquafresh Fresh & Minty), then expectorated the slurry into a collection vessel after 30 and 60 seconds of supervised brushing. Total foam volume was immediately measured. Subjects then rinsed with sterile water for 10 seconds and expectorated into the same vessel, which was processed for microbiological analysis. Total viable anaerobes and total viable VSC-producing bacteria were enumerated using appropriate selective media. RESULTS: No statistically significant difference was indicated between the gel-to-foam dentifrice and either of the control dentifrices with respect to the level of total viable anaerobes (P > 0.05). The level of total viable VSC-producing bacteria was statistically significantly lower for the gel-to-foam dentifrice (Aquafresh Iso-active) than for one of the control dentifrices (Aquafresh Fresh & Minty) (P < 0.05), and numerically lower for the gel-to-foam dentifrice than for the other control dentifrice (Aquafresh Extreme Clean) (P = 0.0526). Use of the gel-to-foam dentifrice resulted in statistically significantly greater (P < 0.05) foam generation than the two control dentifrices.

Clinical investigation of the antiplaque efficacy of a new variant of a commercially available triclosan/copolymer/fluoride dentifrice.

OBJECTIVE: The objective of two single-blind, three-treatment, crossover design, clinical studies was to evaluate the antiplaque efficacy using the Modified Gingival Margin Plaque Index (MGMPI) scores of three dentifrices: 1) a dentifrice containing 0.3% triclosan/2.0% polyvinylmethyl ether/maleic acid (PVM/MA) copolymer/sodium fluoride in a 17% dual silica base (Colgate Total Advanced Toothpaste-Test Dentifrice); 2) a commercially available dentifrice containing 0.3% triclosan/2.0% PVM/MA copolymer/sodium fluoride in a 10% high-cleaning silica base (Colgate Total Toothpaste-Positive Control Dentifrice); and 3) a commercially available dentifrice containing 0.243% sodium fluoride in a regular silica base (Colgate Winterfresh Gel-Negative Control Dentifrice). METHODS: In each study, subjects reported to the clinical facility, and those who met the inclusion/exclusion criteria were given a complete oral prophylaxis, a soft-bristled toothbrush, and a commercially available dentifrice (Colgate Cavity Protection Fluoride Toothpaste). They were instructed to use these products exclusively for seven days (washout period), after which time they reported back to the clinical facility and were randomized into three treatment groups. All subjects then brushed their teeth for one minute with a full ribbon (approximately 1.5 gm) of Colgate Cavity Protection Fluoride Toothpaste, and immediately followed with a one-minute brushing using a full ribbon of one of the three study dentifrices. Subjects then rinsed with a red disclosing solution (Butler Red-Cote) and had their teeth and gums examined to assess their plaque content. They returned to the clinical facility after 24 hours of no oral hygiene to again have their teeth and gums examined to assess their plaque content. As per the crossover clinical design, the same methods and materials were used until all subjects used all three study treatments. RESULTS: Seventeen subjects in the first study and 16 subjects in the second study complied with the protocol and completed all phases of the study. Two-way ANOVA results from both studies showed that there was no difference in mean delta MGMPI scores between the groups using the Test Dentifrice and the Positive Control Dentifrice. Results also showed that there was a statistically significant difference (p < 0.05) in delta MGMPI scores between both the Test Dentifrice treatment and the Positive Control Dentifrice treatment when compared to the Negative Control Dentifrice. CONCLUSION: A new improved dentifrice containing 0.2% triclosan/3.0% PVM/MA copolymer/sodium fluoride in a 17% dual silica base is comparable in controlling dental plaque when compared to a Positive Control Dentifrice containing 0.3% triclosan/2.0% PVM/MA copolymer/sodium fluoride in a 10% high-cleaning silica base, and is statistically significantly better in controlling dental plaque when compared to a Negative Control Dentifrice containing 0.243% sodium fluoride in a silica base.

Statistical approach for risk assessment of aflatoxin sampling plan used by manufacturers for raw shelled peanuts.

Processed food manufacturers often use acceptance sampling plans to screen out lots with unacceptable levels of contamination from incoming raw material streams. Sampling plan designs are determined by specifying sample sizes, sample preparation methods, analytical test methods, and accept/reject criteria. Sampling plan performance can be indicated by plotting acceptance probability versus contamination level as an operating characteristic (OC) curve. In practice, actual plan performance depends on the level of contamination in the incoming lot stream. This level can vary considerably over time, among different crop varieties, and among locales. To better gauge plan performance, a method of coupling an OC curve and crop distributions is proposed. The method provides a precise probabilistic statement about risk and can be easily performed with commercial spreadsheet software.

The development of a new desensitising mouthwash containing arginine, PVM/MA copolymer, pyrophosphates, and sodium fluoride--a hydraulic conductance study.

OBJECTIVE: To investigate the ability of a novel mouthwash comprised of 0.8% arginine, PVM/MA copolymer, pyrophosphates, and 0.05% sodium fluoride in an alcohol-free base (Pro-Argin™ Mouthwash Technology) to reduce dentine permeability. METHODS: Hydraulic conductance was used to assess the dentine permeability effects of the arginine mouthwash. Aqueous solutions containing arginine and PVM/MA copolymer were studied in the initial stage of the method development. The acid resistance was tested with a cola drink challenge. Finally, a blinded study was carried out to determine the occlusion of the arginine mouthwash in comparison to a negative control mouthwash. RESULTS: Dentine discs treated with the arginine mouthwash showed an average fluid reduction of 42%, which was statistically, significantly better than the fluid reduction for the negative control mouthwash. In addition, experiments using simple solutions of arginine and PVM/MA copolymer, alone and in combination, demonstrated that the combination of the two was required to provide a relevant occlusion benefit. Finally, the occlusion provided by the arginine mouthwash was maintained after exposure to an acid challenge. CONCLUSION: The exclusive combination of ingredients in the arginine mouthwash has been proven to be efficacious in decreasing dentine fluid flow as measured by hydraulic conductance. The new mouthwash works by occlusion, due to the unique combination of arginine, PVM/MA copolymer and pyrophosphates.

Staphylococcus aureus growth boundaries: moving towards mechanistic predictive models based on solute-specific effects.

The formulation of shelf-stable intermediate-moisture products is a critical food safety issue. Therefore, knowing the precise boundary for the growth-no-growth interface of Staphylococcus aureus is necessary for food safety risk assessment. This study was designed to examine the effects of various humectants and to produce growth boundary models as tools for risk assessment. The molecular mobility and the effects of various physical properties of humectants, such as their glass transition temperatures, their membrane permeability, and their ionic and nonionic properties, on S. aureus growth were investigated. The effects of relative humidity (RH; 84 to 95%, adjusted by sucrose plus fructose, glycerol, or NaCl), initial pH (4.5 to 7.0, adjusted by HCl), and potassium sorbate concentration (0 or 1,000 ppm) on the growth of S. aureus were determined. Growth was monitored by turbidity over a 24-week period. Toxin production was determined by enterotoxin assay. The 1,792 data points generated were analyzed by LIFEREG procedures (SAS Institute, Inc., Cary, N.C.), which showed that all parameters studied significantly affected the growth responses of S. aureus. Differences were observed in the growth-no-growth boundary when different humectants were used to achieve the desired RH values in both the absence and the presence of potassium sorbate. Sucrose plus fructose was most inhibitory at neutral pH values, while NaCl was most inhibitory at low pH values. The addition of potassium sorbate greatly increased the no-growth regions, particularly when pH was <6.0. Published kinetic growth and survival models were compared with boundary models developed in this work. The effects of solutes and differences in modeling approaches are discussed.