A validated photonumeric scale for infraorbital dark circles and its application in evaluating the efficacy of a cosmetic treatment product in a split-face randomized clinical trial.

OBJECTIVE: As a result of their complex aetiology and periodicity, dark circles are difficult to characterize and measure, with current assessment techniques relying on specialist equipment, image analysis or proprietary grading scales. There is therefore a need to develop and validate a photonumeric scale for assessing infraorbital dark circles, which can provide an objective and consumer relevant tool for evaluating this condition and the efficacy of treatment products and procedures. METHODS: A panel of expert clinical evaluators reviewed approximately three thousand facial photographs collected over a 5-year period and selected images representing a dynamic range of dark circles. A 10-point photonumeric scale was created, with corresponding descriptors and images for each grade of the scale. To rigorously validate the scale, linearity, sensitivity and precision were assessed by colorimetry and in-clinic evaluation. Reproducibility was assessed photographically with both experienced and inexperienced clinical evaluators, whereas intragrader repeatability was assessed live in-clinic. The scale was then employed in a split-face randomized clinical trial on 58 subjects to evaluate the efficacy of a cosmetic treatment product over 8 weeks. RESULTS: Colour analysis of the images showed the scale was linear, with statistically significant correlations observed when colour data (CIElab; Individual Typology Angle) were plotted against the corresponding grades (r > 0.9, P < 0.001). Colour difference (Delta E) was calculated between the infraorbital zone and the surrounding skin, and when data were plotted against the grades, a statistically significant correlation was observed (r = 0.99, P < 0.01). The magnitude of the Delta E suggested that changes in grade are visibly perceptible to the human eye, and therefore, the scale is sensitive and clinically relevant. Intergrader reproducibility showed strong correlation (0.96) and >90% agreement between experienced evaluators, whereas intragrader repeatability assessment showed >90% perfect agreement between grades. Use of this scale in a clinical trial demonstrated the efficacy of a cosmetic product, with a mean statistically significant (P < 0.001) decrease in grade of 0.74 compared to baseline, and 0.59 versus the untreated control, after 8 weeks of treatment. CONCLUSION: Our photonumeric scale for infraorbital dark circles is sensitive and robust and provides an objective and easy-to-use tool to evaluate dark circles and their treatment.

OBJECTIF: En raison de leur étiologie et de leur périodicité complexes, les cernes sont difficiles à caractériser et à mesurer, les techniques d'évaluation actuelles reposant sur des équipements spécialisés, l'analyse d'images ou des échelles de notation exclusives. Il est donc nécessaire de développer et de valider une échelle photonumérique pour évaluer les cernes infraorbitaires, laquelle peut fournir un outil objectif et pertinent pour le consommateur et tester l'efficacité des produits et des procédures de traitement. MÉTHODES: Un panel d'évaluateurs cliniques experts a examiné environ trois mille photographies du visage recueillies sur une période de 5 ans, ainsi que des images sélectionnées représentant une plage dynamique de cernes. Une échelle photonumérique à 10 points a été créée, avec des descripteurs et des images correspondants à chaque grade de l'échelle. Afin de valider rigoureusement l'échelle, la linéarité, la sensibilité et la précision ont été évaluées par colorimétrie et en clinique. La reproductibilité a été évaluée sur le plan photographique par des évaluateurs cliniques expérimentés et inexpérimentés, tandis que la répétabilité intragrade a été évaluée en direct en clinique. L'échelle a ensuite été utilisée dans un essai clinique randomisé à deux parties sur 58 sujets, afin d'évaluer l'efficacité d'un produit de traitement cosmétique sur 8 semaines. RÉSULTATS: L'analyse des couleurs des images a montré que l'échelle était linéaire, avec des corrélations statistiquement significatives observées lorsque les données de couleurs (CIElab ; angle de typologie individuel) ont été tracées par rapport aux grades correspondants (r > 0,9, P < 0,001). La différence de couleur (Delta E) a été calculée entre la zone infraorbitaire et la peau environnante, et lorsque les données ont été tracées par rapport aux grades, une corrélation statistiquement significative a été observée (r = 0,99, P < 0,01). L'ampleur du delta E a suggéré que les changements de grade sont visiblement perceptibles à l'œil humain, l'échelle étant par conséquent sensible et cliniquement pertinente. La reproductibilité intergrade a montré une forte corrélation (0,96) et une concordance > 90 % entre les évaluateurs expérimentés, tandis que l'évaluation de la répétabilité intragrade a montré une concordance parfaite > 90 % entre les grades. L'utilisation de cette échelle lors d'un essai clinique a démontré l'efficacité d'un produit cosmétique, avec une diminution moyenne statistiquement significative (P < 0,001) du grade de 0,74 par rapport à la référence, et de 0,59 par rapport au témoin non traité, après 8 semaines de traitement. CONCLUSION: Notre échelle photonumérique pour les cernes infraorbitaires est sensible et robuste, fournissant un outil objectif et facile à utiliser afin d'évaluer les cernes et leur traitement.

A theoretical and experimental study of the temporal reduction in UV protection provided by a facial day cream.

OBJECTIVE: To investigate how the UV protection provided by a facial day cream reduces over the course of a day. METHODS: We developed a theoretical model using a Monte Carlo random sampling approach to estimate the variation in local thickness, and hence local effective SPF, at several different sites over the face. The input variables, which are labelled SPF, average application thickness, homogeneity of the product on the skin and the ability of the product to bind to the skin, allow examination of how these different factors affect the delivered photoprotection. We compared the results of our modelling with experimental determination of the binding of an oil-in-water moisturizing day cream with a rated SPF of 15 at various times over the course of a day by means of UV photography and digital image analysis. RESULTS: We demonstrated good agreement between our theoretical predictions of the temporal reduction in product thickness and the experimental observations. We used our modelling approach to show that a substantial reduction in lifetime UV burden on the face could be achieved by a daycare product delivering 3-fold (or greater) protection over the face. CONCLUSION: Comparison with experimental data confirmed the robustness and validity of our model, which predicts that products intended for daily use need to be formulated carefully and applied uniformly, and to have a half-life of binding to the skin of several hours. Products that bind less well to the skin, or are applied non-uniformly, are likely to be providing inadequate protection with regards to influencing the rate of photoaging of the skin. Our data suggest that after a single, realistic application of a day cream rated SPF15, consumers' faces remain protected to at least an average of 5-fold around the middle of the day, especially pertinent to indoor workers who are likely to be exposed to maximum UV levels as they venture outside during their lunch break.

Photophysical properties of the photosensitizer pheophorbide a studied at high photon flux densities.

The photophysical properties of pheophorbide a (Pheo a) under two-step laser activation were investigated. For the first time quantum yields of higher excited state formation were calculated. It was shown that the quantum yields of the formation of these states depend strongly on the pulse duration of the excitation source. The nonlinear properties of Pheo a are quite different in dependence on the excitation wavelength but the quantum yields of the higher excited state formation in both cases (lambda exc = 337 nm and lambda exc = 667 nm) rise up increasing the photon flux density of the laser light up to 10(26) phot cm-2 s-1. A further increase of the photon flux density has no effect on the quantum yields.

Selection of oral microbial adhesion antagonists using biotinylated Streptococcus sanguis and a human mixed oral microflora.

A microtitre assay has been developed using hydroxyapatite-coated wells and Streptococcus sanguis NCTC 10904 at 10(7) cells per ml. A number of models representing toothpaste and mouthwash usage were adopted to detect the anti-adherent efficacy of a polyvinylmethylether maleic acid copolymer (PVM/MA), polyoxypropylene/polyoxyethylene block copolymer (PO/EO), two casein-derived peptides and selected silicones. The results not only confirmed the anti-adherence property of the selected components but also indicated possible molecular interactions leading to the observed performance. To account for the diversity of oral microbial cells in vivo, a further testing system was developed. This involved submerging a hydroxyapatite disc in a mixed culture of human salivary microbial cells, and exposing it to different treatments using the active component either in an aqueous dispersion or in a toothpaste. The effect of toothpastes containing PO/EO, dimethicone copoyol or PVM/MA was investigated over a 4-h incubation with microflora. These tests showed that in a toothpaste formulation the anti-adherent efficacy may be reduced when compared with an aqueous dispersion containing the same or nearly the same concentration of the active component.

A study into the plaque-inhibitory activity of experimental toothpaste formulations containing antimicrobial agents.

BACKGROUND/AIMS: The use of specific antimicrobial agents in toothpastes may help reduce plaque and gingivitis. There would also appear to be some value in formulating products that contain combinations of such agents that may potentiate any activity present. The aims of this exploratory and pragmatic study were twofold: (1) Exploratory: to compare the effects on plaque re-growth of two zinc citrate/triclosan formulations, one of which contained bromochlorophene and hence demonstrate any additional beneficial effects produced by the addition of the phenol. (2) Pragmatic: to assess whether both pastes were significantly better than a benchmark control, proprietary fluoride toothpaste at inhibiting plaque formation. METHODS: Following an initial prophylaxis to remove all plaque and calculus, toothpaste slurry rinses were used over a 96 h period by 24 volunteers, while omitting all other oral hygiene procedures. After 24, 48 and 96 h, plaque was measured by plaque area and by plaque index. For comparative purposes, a conventional commercial fluoride toothpaste rinse was also used as a benchmark control in this triple cross-over double-blind study. RESULTS: With one exception, comparisons between the three pastes failed to show any significant differences in plaque accumulation at 96 h whether assessed by plaque index or area. At this time period, significantly more plaque was seen with the zinc citrate paste without bromochlorophene, compared with that of the control paste. CONCLUSIONS: The findings from this study failed to demonstrate a plaque-inhibitory action from the two novel formulations beyond that of a conventional benchmark toothpaste, although overall levels of plaque formed by the volunteers, especially on the control paste were generally lower than in previous studies. Nevertheless, it remains to be determined whether the test formulations could exert a direct anti-inflammatory action against gingivitis by way of the triclosan delivery system. Neither test formulation was subsequently marketed.

The measurement of tooth whiteness by image analysis and spectrophotometry: a comparison.

Digital image capturing and analysis techniques have been used to measure the colour of teeth and to compare with spectrophotometric results and visual observations. A non-linear image analysis approach was developed and, for the colour range of human teeth, allows device-dependant digital camera colour data to be quantitatively transformed to Commission Internationale de l'Eclairage (CIE) colorimetric values. With reference to a CIE standard illuminant, two different lighting arrays have been used. For flat and non-translucent white and yellow surfaces, spectrophotometric results showed that this transformation achieves required accuracy. It was found, in all of the present studies, which included measurements on the VITA Lumin Vacuum shade guide and extracted teeth, that spectrophotometry invariably underestimated values of the CIE whiteness index. However, the results from these two types of measurement correlated well. There was also a reasonably good correlation between earlier data obtained by visual assessment and the present data by the two instrumental methods. For extracted teeth, both instrumental methods used in this work did not confirm a whitening effect for 2-min brushing with toothpaste, but did show significant whitening results for bleaching with 15% hydrogen peroxide.

A study to assess the plaque inhibitory action of a newly formulated triclosan toothpaste.

BACKGROUND/AIMS: Triclosan containing toothpastes have been noted for their potential to inhibit plaque and gingival inflammation. The aim of this study was to determine whether a toothpaste containing triclosan and an enhanced fluoride system would inhibit de novo plaque formation beyond that of a non-triclosan, conventional fluoride toothpaste. METHODS: This study used a 4-day plaque regrowth model in which 24 volunteers used toothpaste rinses as the only form of oral hygiene. Following a prophylaxis and a single brushing with the toothpastes, 2x daily rinsing with toothpaste slurries was used over the following 96 h. RESULTS: After 24 h, there was no difference in plaque area between the triclosan paste and its control paste. After 96 h, a reduction in plaque score of 5% was noted for the test toothpaste compared to the control paste which was statistically significant (p=0.028). For plaque area this reduction was increased to 16%, which was also significant (p=0.006). CONCLUSIONS: These findings would appear to warrant further investigation into the potential value of the paste in inhibiting both plaque and gingivitis.

A study to assess the plaque inhibitory activity of a new triclosan mouthrinse formulation.

BACKGROUND/AIMS: Toothpastes and mouthrinses containing triclosan have been shown to be of some value at inhibiting both plaque and gingivitis. However much improved activity can be obtained by the addition of other chemicals which increase substantivity or antimicrobial activity. The present study was designed to determine whether a new mouthwash formulation containing a triglyceride oil was capable of reducing plaque reformation when compared to a control rinse containing neither triclosan or oil. METHODS: A total of 24 subjects took part in a double-blind, single-centre, cross-over study in which rinses were used as the only form of oral hygiene over a 4-day period. On the 1st day of each period, the subjects were given a prophylaxis to remove all plaque and calculus deposits. A single supervised rinse was taken and subsequent 2x daily rinses over the following 3 days. 24 and 96 h after the prophylaxis, the volunteers returned to the clinic, the plaque disclosed and assessed by plaque index and area. The test procedure and wash-out phase were repeated until all of the subjects had used both rinses. RESULTS: After 24 h, a 12% reduction in plaque score and a 25% reduction in plaque area was noted for the triclosan/oil rinse compared to the control rinse; however, these reductions were not significant (p>0.05). After 96 h, the triclosan/ oil rinse failed to produce a numerical or statistical reduction in plaque whether measured by plaque score or area. CONCLUSIONS: These findings would suggest that the triclosan/oil rinse would be of little value at inhibiting dental plaque whether used alone or as an adjunct to conventional oral hygiene measures.

The effects of a potassium citrate, cetylpyridinium chloride, sodium fluoride mouthrinse on dentine hypersensitivity, plaque and gingivitis. A placebo-controlled study.

Home-use studies on dentine hypersensitivity have most commonly involved toothpastes and rarely have mouthrinses been employed. Potassium and/or fluoride toothpastes have been shown effective in the treatment of dentine hypersensitivity. The aim of this study was to evaluate the effectiveness of a total formulation, containing potassium citrate, sodium fluoride, cetylpyridinium chloride mouthrinse compared to the base rinse minus actives in the reduction of dentine hypersensitivity. The study was a randomised placebo controlled, double blind parallel design. At a screening visit, 90 adult subjects were recruited who were suffering from dentine hypersensitivity from at least 1 tooth responding to tactile stimulation (45gm pressure) and had at least 2 teeth responding to evaporative stimulation (air blast). During a washout period of 28 days and throughout the 56-day study period, subjects used a soft filament toothbrush and standard fluoride toothpaste. At baseline (day 1), threshold sensitivities to incremental tactile (10 g to 70 g) and evaporative stimuli were determined. Gingival health was assessed by recording bleeding on probing at 25 g pressure at mesiobuccal and lingual sites. Plaque scores from buccal and lingual surfaces of disclosed teeth were also measured. Subjects then used the prescribed rinse, 10 ml for at least 30 s after brushing 2x per day returning on days 28 and 56 for rescoring of sensitivity, gingivitis and plaque. Data from 88 subjects were used with the intent to treat analyses and 83 in the completely evaluable analyses. Groups were well balanced for demographic data and product returns suggested good compliance. Both groups showed highly significant improvements in tooth sensitivity. The pattern was for greater improvement in the test compared to the control group (statistically significant for the plaque score), whereas bleeding scores, already low, showed no change in either group. By definition, the placebo rinse could not have exerted any therapeutic action; the study therefore provides clear direct evidence as to the magnitude (30%-40%) of the little studied, but assumed, placebo response in dentine hypersensitivity trials.

Synergy of binary poly(oxypropylene-oxyethylene) copolymers in reducing retention of Streptococcus sanguis to hydroxyapatite.

Binary poly(oxypropylene-oxyethylene) block copolymer systems have been investigated as a non-bactericidal approach to reduce the retention of an oral bacterium, Streptococcus sanguis. Using a previously validated hydroxyapatite-coated microtitre model to simulate the tooth, the performance of copolymer pairs was measured experimentally. A synergy index and an efficacy index were defined to describe the reduction of bacterial retention by the binary systems that comprise the copolymer pairs. Relationships between the synergy and efficacy indices and their associated compositions are given. The results obtained have been rationalised using a previously developed theoretical approach in conjunction with the binding energetics of species to surfaces.