Efficacy of a mouthwash containing 0.8% arginine, PVM/MA copolymer, pyrophosphates, and 0.05% sodium fluoride compared to a negative control mouthwash on dentin hypersensitivity reduction. A randomized clinical trial.

OBJECTIVE: The objective of this eight week, single-center, two-cell, double-blind, and randomized clinical study was to evaluate the dentin hypersensitivity reduction efficacy of a mouthwash using Pro-Argin™ Mouthwash Technology containing 0.8% arginine, PVM/MA copolymer, pyrophosphates, and 0.05% sodium fluoride in an alcohol-free base ("Arginine Mouthwash") compared to an ordinary mouthwash without any active ingredients ("Negative Control"). METHODS: Qualifying subjects who presented two hypersensitive teeth with a tactile hypersensitivity score between 10 and 50 g of force, and an air blast hypersensitivity score of 2 or 3 participated in this study and were randomized into one of two treatment groups. Subjects brushed with the toothbrush and fluoride toothpaste provided and then rinsed with 20 mL of their assigned mouthwash for 30s twice daily. Subjects refrained from eating or drinking for 30 min after rinsing. Dentin hypersensitivity assessments, as well as examinations of oral hard and soft tissues, were conducted at the baseline visit and again after two weeks, four weeks and eight weeks of product use. RESULTS: Ninety (90) subjects entered and completed the eight week study. After two weeks, four weeks and eight weeks of product use, subjects in the Arginine Mouthwash group exhibited statistically significant (p<0.05) improvements in mean tactile and air blast hypersensitivity scores as compared to the Negative Control Mouthwash. CONCLUSION: The results of this study support the conclusion that the Arginine Mouthwash provides a significant reduction in dentin hypersensitivity after eight weeks of product use as compared to a Negative Control mouthwash.

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.

Efficacy of a mouthwash containing 0.8% arginine, PVM/MA copolymer, pyrophosphates, and 0.05% sodium fluoride compared to a commercial mouthwash containing 2.4% potassium nitrate and 0.022% sodium fluoride and a control mouthwash containing 0.05% sodium fluoride on dentine hypersensitivity: a six-week randomized clinical study.

OBJECTIVE: Evaluate the efficacy of 0.8% arginine, potassium nitrate and sodium fluoride mouthwashes on dentine hypersensitivity reduction. METHODS: Six week randomized, double blinded, two cell, parallel single centre clinical study in the Dominican Republic; subjects were randomized into three treatment groups: mouthwash containing 0.8% arginine, PVM/MA copolymer, pyrophosphates, and 0.05% sodium fluoride in an alcohol-free base (arginine); mouthwash containing 2.4% potassium nitrate and 0.022% sodium fluoride (potassium nitrate); a control mouthwash containing 0.05% sodium fluoride (negative control). Tactile and air-blast dentine hypersensitivity assessments were conducted at baseline, thirty minutes post rinsing and two, four, and six weeks of twice-daily product use. For treatment group comparisons, ANCOVA and post hoc Tukey's pair-wise comparisons (α=0.05) were done. RESULTS: Seventy-five subjects were enrolled; 69 subjects completed the study. There were no differences after thirty minutes of a single use, among the three groups with respect to mean tactile and air blast hypersensitivity scores compared to potassium nitrate and negative control mouthwashes (p<0.05). The arginine group presented a statistically significant improvement in the mean tactile scores compared to potassium nitrate and negative control groups after two, four, and six weeks (p<0.001) of product use; the arginine group showed a statistically significant enhancement in air blast hypersensitivity mean scores compared to potassium nitrate and negative control groups after two (p=0.001), four (p<0.001), and six weeks (p<0.001) of product use. CONCLUSION: A mouthwash containing arginine provides a significant and superior reduction in dentine hypersensitivity compared to potassium nitrate and a negative control mouthwash after two weeks.

Mode of action studies of a new desensitizing mouthwash containing 0.8% arginine, PVM/MA copolymer, pyrophosphates, and 0.05% sodium fluoride.

OBJECTIVE: The mode of action of an arginine mouthwash using the Pro-Argin™ Mouthwash Technology, containing 0.8% arginine, PVM/MA copolymer, pyrophosphates and 0.05% sodium fluoride, has been proposed and confirmed as occlusion using a variety of in vitro techniques. METHODS: Quantitative and qualitative laboratory techniques were employed to investigate the mode of action of the new arginine mouthwash. Confocal laser scanning microscopy (CSLM) and atomic force microscopy (AFM) investigated a hydrated layer on dentine surface. Electron spectroscopy for chemical analysis (ESCA), secondary ion mass spectroscopy (SIMS) and near-infrared spectroscopy (NIR) provided information about its chemical nature. RESULTS: CLSM was used to observe the formation of a hydrated layer on exposed dentine tubules upon application of the arginine mouthwash. Fluorescence studies confirmed penetration of the hydrated layer in the inner walls of the dentinal tubules. The AFM investigation confirmed the affinity of the arginine mouthwash for the dentine surface, supporting its adhesive nature. NIR showed the deposition of arginine after several mouthwash applications, and ESCA/SIMS detected the presence of phosphate groups and organic acid groups, indicating the deposition of copolymer and pyrophosphates along with arginine. CONCLUSION: The studies presented in this paper support occlusion of the dentine surface upon the deposition of an arginine-rich layer together with copolymer and phosphate ions from an alcohol-free mouthwash containing 0.8% arginine, PVM/MA copolymer, pyrophosphates and 0.05% sodium fluoride.

Anti-hypersensitivity mechanism of action for a dentifrice containing 0.3% triclosan, 2.0% PVM/MA copolymer, 0.243% NaF and specially-designed silica.

PURPOSE: To evaluate the laboratory dentin occlusion efficacy and effects on dentin permeability of a new multi-benefit dentifrice in order to gain insight into the mechanism of action of a novel technology for dentin hypersensitivity relief based on a specially-designed silica and copolymer system. METHODS: Acid-etched human dentin was evaluated with confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) after treatment with one of the following: (1) a dentifrice containing 0.3% triclosan, 2.0% PVM/MA copolymer, 0.243% sodium fluoride with specially designed silica (Test Dentifrice 1); (2) a dentifrice containing 0.3% triclosan and the same overall silica loading as Test Dentifrice 1 but without copolymer and the specially-designed silica (Placebo Dentifrice); (3) a commercially-available dentifrice containing 0.454% stannous fluoride in a silica base with sodium hexametaphosphate and zinc lactate (Test Dentifrice 2); and (4) a commercially-available non-sensitive dentifrice containing 0.243% sodium fluoride in a silica base (Negative Control Dentifrice). The composition of dentin treated with either Test Dentifrice 1 or Negative Control Dentifrice was analyzed using energy dispersive x-ray (EDX) and electron spectroscopy for chemical analysis (ESCA). To highlight dentin occluding efficacy of the specially-designed silica, dentin was treated with Test Dentifrice 1 formulated with fluorescently-tagged specially-designed silica and resulting occlusion followed with CLSM. The dentin occluding abilities of Test Dentifrices 1 and 2 were compared with the Negative Control dentifrice using CLSM after a 4-day cycling model consisting of twice daily dentifrice treatment and four acid challenges. Effects of treatment with Test Dentifrices 1 or 2 on dentin permeability and subsequent resistance of occluding deposits to acid dissolution and dislodgement by pulpal pressure were assessed using hydraulic conductance. RESULTS: Dentin specimens treated with Test Dentifrices 1 and 2 were significantly occluded compared to Placebo Dentifrice and Negative Control Dentifrice when visualized with CLSM. The level of occlusion remaining after challenge with cola was highest for dentin treated with Test Dentifrice 1 in CLSM xz views. Test Dentifrice 1 produced dentin surface deposits and tubule plugs containing silicon in addition to calcium and phosphorus as indicated by ESCA and EDX. CLSM visualization of fluorescently-tagged material confirmed occlusion by the specially-designed silica which was localized at the dentin tubule openings. Imaging of dentin by CLSM after the 4-day cycling model revealed a significantly higher amount of occluded tubules for dentin treated with Test Dentifrice 1 compared to the Negative Control Dentifrice or Test Dentifrice 2. Etched dentin treated with the Test Dentifrice 1 was significantly less permeable compared to that treated with the Negative Control Dentifrice, exhibiting over 80% reduction in dentin permeability. The occlusion provided by the Test Dentifrice 1 was maintained and provided significantly better reduction in permeability after extended pulpal pressure and acid challenge compared to dentin treated with Test Dentifrice 2.

Langmuir and Langmuir-Blodgett films containing a porphyrin-ruthenium complex.

The fabrication of supramolecular structures from the tetraruthenated porphyrin-containing phosphines, {TPyP[RuCl3(dppb)]4}, RuTPyP, is demonstrated with Langmuir and Langmuir-Blodgett films. The surface pressure-molecular area isotherms (pi-A) point to an edge-on arrangement for the RuTPyP molecules in the condensed state. Weak aggregation in the Langmuir films was indicated by non-zero surface potentials at large areas per molecule and a slight red shift in the ultraviolet-visible absorption spectrum in comparison to the spectrum in solution. Further aggregation occurs in the Z-type Langmuir-Blodgett films, which was confirmed with ultraviolet-visible spectroscopy of the deposited films. Fourier transform infrared and Raman spectroscopic data for powder and Langmuir-Blodgett films indicate that the RuTPyP molecules are chemically stable in Langmuir-Blodgett films regardless of the contact with water during film fabrication. The nanostructured nature of the Langmuir-Blodgett films was manifested in cyclic voltammetry due to the high sensitivity of the metallic centers in RuTPyP. Electrodes modified with Langmuir-Blodgett films exhibit an anodic peak at 100 mV and a cathodic peak at 7 mV, which is assigned to RuIII/RuII redox processes. Furthermore, Langmuir-Blodgett films from RuTPyP showed electrocatalytic activity for oxidation of benzyl alcohol, illustrated by a large shift of 100 mV in the anodic peak at 400 mV, while electropolymerized and cast films of the same compound displayed smaller and no activities, respectively.

The interaction between OPH and paraoxon at the air-water interface studied by AFM and epifluorescence microscopies.

The paraoxon hydrolysis reaction catalyzed by organophosphorus hydrolase (OPH) monolayer at the air-water interface was studied. OPH-paraoxon interactions, occurring at the two-dimensional interface, by close-packed, highly orientated OPH monolayer, were investigated by several different surface chemistry techniques; e.g. surface pressure area isotherms, atomic force microscopy (AFM), and in situ epifluorescence microscopy. The characterization of OPH Langmuir and Langmuir-Blodgett films prepared in both the presence and absence of paraoxon, demonstrated significantly distinctive feature when compared with one another. Continuous growth of the OPH aggregates is a distinct phenomenon associated with hydrolysis, in addition to the pH changes in the local environment of the enzyme macromolecules.

Self-doping effect in poly(o-methoxyaniline)/poly(3-thiopheneacetic acid) layer-by-layer films.

Nanostructured films from two conducting polymers, poly(o-methoxyaniline) (POMA) and poly(3-thiopheneacetic acid) (PTAA), were fabricated with the layer-by-layer (LBL) technique. The electrochemical response of the LBL films differs from that of a POMA cast film, even in a potential range where PTAA is inactive. This is attributed to differences in the diffusion-controlled charge and mass transport, where distinct ionic species participate in the LBL films, as demonstrated by quartz crystal microbalance measurements. The results show that the transport properties of conducting polymers can be changed by alternation with layers of appropriate materials in LBL films.

Langmuir and Langmuir-Blodgett films of organophosphorus acid anhydrolase.

In this paper, we describe the preparation and characterization of Langmuir and Langmuir-Blodgett (LB) monolayers of the enzyme organophosphorus acid anhydrolase (OPAA). Langmuir films of OPAA were characterized on different subphases, such as phosphate, ammonium carbonate, and bis-tris-propane buffers. Monolayers at the air-water interface were characterized by measuring the surface pressure and surface potential-area isotherms. In situ UV-vis absorption spectra were also recorded from the Langmuir monolayers. The enzyme activity at the air-water interface was tested by the addition of diisopropylfluorophosphate (DFP) to the subphase. LB films of OPAA were transferred to mica substrates to be studied by atomic force microscopy. Finally, a one-layer LB film of OPAA labeled with a fluorescent probe, fluorescein isothiocyanate (FITC), was deposited onto a quartz slide to be tested as sensor for DFP. The clear, pronounced response and the stability of the LB film as a DFP sensor show the potential of this system as a biosensor.

Layer-by-layer self-assembled chitosan/poly(thiophene-3-acetic acid) and organophosphorus hydrolase multilayers.

The aim of this study is to immobilize an enzyme, namely, organophosphorus hydrolase (OPH), and to detect the presence of paraoxon, which is an organophosphorus compound, using the layer-by-layer (LbL) deposition technique. To lift the OPH from the solid substrate, a pair of polyelectrolytes (positively charged chitosan (CS) and negatively charged poly(thiophene-3-acetic acid) (PTAA)) were combined. These species were made charged by altering the pH of the solutions. LbL involved alternate adsorption of the oppositely charged polyions from dilute aqueous solutions onto a hydrophilic quartz slide. This polyion cushion was held together by the electrostatic attraction between CS and PTAA. The growing process was monitored by fluorescence spectroscopy. OPH was then adsorbed onto the five-bilayer CS/PTAA system. This five-bilayer macromolecular structure compared to the solid substrate rendered stability to the enzyme by giving functional integrity in addition to the ability to react with paraoxon solutions. The ultimate goal is to use such a system to detect the presence of organophosphorus compounds with speed and sensitivity using the absorption and fluorescence detection methodologies.