The assessment of different bleaching agents' efficiency on discoloured teeth using image-processing methods.

BACKGROUND: Although triple antibiotic paste (TAP) has been successfully used as an intracanal medicament for regenerative endodontic treatments, TAP has also been shown to cause discolouration. The aim of this study is to investigate the efficacy of different bleaching agents to bleach teeth discoloured from TAP. METHODS: Two hundred extracted human maxillary incisors were evaluated with VITA Easyshade, and 120 teeth were prepared and discoloured by using TAP for three weeks. After colouration, 70 teeth were randomly divided into five groups: Group 1: Negative control, Group 2: Sodium perborate, Group 3: Opalescence Endo, Group 4: Endoperox, and Group 5: Biolase. The colour changes in the third and seventh days' standard images were obtained using stereomicroscopy, RGB and Lab color space transformations were applied to the images. The CIE Lab color system was used, and total color changes (ΔE) were calculated and compared among groups and over time, using analysis of variance testing. RESULTS: At the third day, there was no difference between bleaching materials. At the seventh day, the Biolase group was superior to sodium perborate and there was no difference between other groups. A statistically significant difference was noted between the third and seventh-day measurements for all bleaching protocols. Bleaching effectiveness of all agents increased over time. CONCLUSIONS: Teeth discoloured by using TAP may be bleached by means of the investigated protocols, and colour alteration can be increased over time. The CIE Lab colour system can be used as an alternative, in vitro test for evaluating the bleaching efficiency of bleaching agents.

Polychlorinated dibenzo-p-dioxin and dibenzofuran precursors and formation mechanisms during non-woodpulp chlorine bleaching process.

There is great concern about decreasing the amounts of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) that are formed and emitted during the chlorine bleaching of pulp. The formation of PCDD/Fs during non-woodpulp chlorine bleaching was investigated in the study described here. Wheat straw was separated into three components, cellulose, hemicellulose, and lignin. Chlorination experiments were performed, and lignin and hemicellulose contributed more than cellulose to PCDD/F formation when the pulp was bleached using chlorine. The chemical components of lignin were identified by gas chromatography mass spectrometry, and nine possible PCDD/F precursors were quantified by gas chromatography tandem mass spectrometry. Spiked chlorination experiments were performed to investigate the effects of these compounds on PCDD/F formation. 4-Ethyl-2-methoxyphenol had the strongest effect on PCDD/F formation, followed by p-chlorophenol, and guaiacol. All the test compounds promoted polychlorinated dibenzofuran formation but had limited effects on polychlorinated dibenzo-p-dioxin formation. The results allowed mechanisms for the formation of PCDD/Fs from phenol, chlorophenol, catechol, and guaiacol to be proposed.

Efficacy of bleach baths in reducing severity of atopic dermatitis: A systematic review and meta-analysis.

BACKGROUND: Bleach baths have been proposed as a treatment for decreasing the severity of atopic dermatitis (AD). However, conflicting results have been found regarding their efficacy. OBJECTIVE: To determine the efficacy of bleach vs water baths at decreasing AD severity. METHODS: We performed a systematic review of all studies evaluating the efficacy of bleach baths for AD. Cochrane, EMBASE, GREAT, LILACS, MEDLINE, and Scopus were searched. Two authors independently performed study selection and data extraction. RESULTS: Five studies were included in the review. Four studies reported significantly decreased AD severity in patients treated with bleach on at least 1 time point. However, of 4 studies comparing bleach with water baths, only 2 found significantly greater decreases in AD severity with bleach baths, 1 found greater decreases with water baths, and 1 found no significant differences. In pooled analyses, there were no significant differences observed between bleach vs water baths at 4 weeks vs baseline for the Eczema Area and Severity Index (I2 = 98%; random effect regression model, P = .16) or body surface area (I2 = 96%; P = .36). CONCLUSION: Although bleach baths are effective in decreasing AD severity, they do not appear to be more effective than water baths alone. Future larger-scale, well-designed randomized controlled trials are needed.

Comparison of intracoronal bleaching methods on teeth discolored by different antibiotic pastes.

AIM: To compare the bleaching efficacy of sodium perborate with different activation methods on crowns discolored by two different antibiotic pastes. MATERIALS AND METHODS: Eighty-five extracted human incisors were prepared to size #30 using ProTaper rotary instruments. After chemomechanical preparation and irrigation procedures, the specimens received triple antibiotic paste (TAP, n = 40), minocycline paste (MP, n = 40), or calcium hydroxide (n = 5, control group) and coronally sealed with temporary filling material. Spectrophotometric readings were obtained on day 0-week 4. Data were analyzed with the Mann-Whitney U-test and Wilcoxon sign test (P < 0.05). Sodium perborate was then inserted into the pulp chambers of discolored teeth (four subgroups, n = 10) and activated by heat or ultrasonically using two different frequencies and times. Spectrophotometric readings were obtained on days 3-7. Data were analyzed by the Mann-Whitney U-test and Kruskal-Wallis test (P > 0.05). RESULTS: Both groups showed statistically significant coronal discoloration at each time interval (P < 0.01), but their final shades did not significantly differ between the groups (P > 0.05). Although the MP subgroups exhibited more bleaching than the TAP subgroups on days 3 and 7, the difference was not significant (P > 0.05). The bleaching results for the sodium perborate activation techniques did not significantly differ among groups (P > 0.05). CONCLUSIONS: Both antibiotic pastes induced crown discoloration that was reversible using all sodium perborate bleaching techniques.

Assessment of the efficacy and safety of a new complex skin cream in Asian women: A controlled clinical trial.

BACKGROUND: Medical products such as hydroquinone and tretinoin have been widely used to treat various types of skin hyperpigmentation. However, these products are limited in daily use given their adverse effects. Other alternative agents with fewer adverse side effects have been developed. However, single agents often do not produce satisfactory results. AIMS: To evaluate the efficacy and safety of a new brightening complex cream containing niacinamide, tranexamic acid, oxyresveratrol, glutathione disulfide, and linoleic acid. PATIENTS AND METHODS: A total of 26 Korean women seeking to lighten their skin were enrolled. The product was applied on the face two times per day for 12 weeks. Standardized photographs were taken at baseline, 4 weeks, 8 weeks, and 12 weeks. Efficacy was assessed using melanin index (MI), erythema index (EI), and chromatic aberration values (L*, a*, and b*). Improvement perceived by investigators and patients was measured as well. RESULTS: The L*-value was increased at 8 weeks (0.7±2.5, P<.05) and at 12 weeks (0.8±2.5, P<.05). The MI was significantly decreased at 8 weeks (-4.2±4.5, P<.05) and at 12 weeks (-3.8±4.8, P<.001). The EI was significantly improved at 12 weeks (-3.2±2.2, P<.001). More than 80% of patients were considered improved at 12 weeks based on the view of the investigators and patients. CONCLUSIONS: The new brightening complex cream was proved to be effective and safe in Asian women.

Efficacy of 10 percent Carbamide Peroxide as an Intracoronal Bleaching Agent in Nonvital Discolored Primary Teeth: An In Vitro Study.

PURPOSE: The purpose of this study was to evaluate, in vitro, the efficacy of 10 percent carbamide peroxide used as an intracoronal bleaching agent in blood-stained primary teeth. METHODS: Thirty extracted primary canines were stained using rabbit blood and randomly divided into two groups of 15 teeth each. Stained teeth in the test group were bleached intracoronally using 10 percent carbamide peroxide for 21 days. The bleaching agent was replaced at days seven and 14. The control group was not subjected to bleaching, and a cotton pellet damped with distilled water was placed in the pulp chamber. Shade alteration from the prestaining value was evaluated using a VITA Easyshade spectrophotometer at days zero, seven, 14, and 21. RESULTS: All specimens in the test group returned to the initial baseline shade, with no significant differences from the prestaining values (P=0.097). Teeth in the control group did not undergo any shade alteration after staining, with no significant differences noted from the prestaining values (P<0.001). CONCLUSIONS: Intracoronal bleaching using 10 percent carbamide peroxide is an effective approach for whitening discolored extracted primary teeth.

Hiperpigmentación facial simétrica adquirida / Acquired Symmetric Facial Hyperpigmentation

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Management of Infectious Aspects of Atopic Dermatitis in Primary Care: A Resident Survey.

Atopic dermatitis (AD) is the most common skin disease encountered by pediatric primary care providers. To describe the knowledge, attitudes, and practices of primary care residents in the management of infectious aspects of pediatric AD, an anonymous web-based survey was offered to all residents in the pediatric and family medicine departments at 3 New York City hospitals. Eighty residents responded. Most (62%) reported seeing 5 to 14 patients with AD monthly. Twenty-seven percent reported obtaining cultures prior to prescribing oral antibiotics most of the time, while 8% reported doing so before giving topical antibiotics. Most respondents (60%) reported never/rarely recommending dilute bleach baths, and family medicine residents were significantly more likely to report never doing so (67% vs 16%, P < .001). Greater education on the use of cultures to guide treatment and potential benefits of dilute bleach baths is needed, especially given increasing antibiotic resistance.

Toothpastes containing abrasive and chemical whitening agents: efficacy in reducing extrinsic dental staining.

This in vitro study evaluated the efficacy of toothpastes containing abrasive and chemical whitening agents in reducing the extrinsic discoloration of dental enamel. Sixty slabs of dentin from human teeth were sealed so that only the enamel surface was exposed. The enamel surfaces were photographed for initial color assessment. Staining was performed by immersing the dental slabs in 0.2% chlorhexidine solution for 2 minutes and then in black tea for 60 minutes. This process was repeated 15 times. Photographs were taken at the end of the staining process, and the slabs were divided into 5 groups (n = 12), 3 to be brushed with toothpastes containing chemical whitening agents (2 containing phosphate salts and 1 containing phosphate salts plus hydrogen peroxide) and 2 to represent control groups (ordinary/nonwhitening toothpaste and distilled water). The dental slabs were subjected to mechanical toothbrushing with toothpaste slurry or distilled water, according to each group's specifications. After brushing, more photographs were taken for color analysis. The results showed a significant reduction in luminosity after the staining process in addition to an increase in the colors red and yellow (P < 0.001). After brushing, there was a significant increase in luminosity and a reduction in both red and yellow (P < 0.001). However, there was no observed difference between the changes in color values in dental enamel slabs brushed with whitening toothpastes and the changes found in slabs brushed with ordinary toothpaste. The whitening toothpastes did not outperform an ordinary toothpaste in the removal of extrinsic staining.

Blanqueamiento ocular quirúrgico. Cosmética versus seguridad / Surgical eye whitening. Cosmesis versus safety

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Hyperpigmentation: types, diagnostics and targeted treatment options.

BACKGROUND: Pigment formation is highly complex. It is involved in inflammation, sun protection and many other processes. For practical purposes, such as exposure time for sun tanning, six skin types are distinguished according to Fitzpatrick, listed in decreasing lightness. The hyperpigmentation commonly occurs in Fitzpatrick skin types III to VI and can have a considerable impact on quality of life. MATERIAL & METHODS: In this article we will give an overview of normal variations of pigmentation and the most often common pigment abnormalities. It also reviews diagnostics and the current targeted treatment options of epidermal and dermal pigmentation. RESULTS: There are multiple hyperpigmented skin lesions, classification of pigmentation is based on histology or Woods light examination. Bleaching agents with phenolic compounds with non-phenolic agens as follow-up therapy appears to be the most beneficial treatment options for the hyperpigmentation. CONCLUSIONS: The effective treatment of pigment disorders is characterized by influence of melanin formation, but the therapy should be based on a the correct diagnosis and always targeted to the other histopathological processes in the skin. The Woods light examination shows clinical aspect of the lesions and may be helpful in the determination of the diagnosis.

In silico prediction of the cosmetic whitening effects of naturally occurring lead compounds.

The identification of tyrosinase inhibitors is important, not only for the treatment of skin hyperpigmentation disorders, such as melasma, but also for the production of cosmetic whitening effects. The aim of this study was the in silico prediction of the naturally occurring lead compounds in three commonly used skin-whitening herbs: Ampelopsis japonica, Lindera aggregata, and Ginkgo biloba. The active ingredients responsible for the whitening effect of these herbs remain largely unknown. The tyrosinase binding affinities and skin permeation, skin irritancy, and corrosive properties of43 natural constituents of the three herbs were predicted by docking simulations using Surflex-Dock and the QSAR-based Dermal Permeability Coefficient Program (DERMWIN) and Skin Irritation Corrosion Rules Estimation Tool (SICRET) implemented in Toxtree. Nine constituents of the three herbs were found to have more advanced binding energies than the gold standard whitening agents, arbutin and kojic acid, but 40 were indicative of at least one skin sensitization alert, and many exhibited poor skin permeability. Linderagalactone c and (+)-n-methyllaurotetanine were found to have the strongest prospects for use in topical formulations, as they achieved high predicted tyrosinase binding scores and displayed good skin permeation properties and minimal potential for skin sensitization and irritation.

Topical 5% tranexamic acid for the treatment of melasma in Asians: a double-blind randomized controlled clinical trial.

BACKGROUND: Topical tranexamic acid has been claimed to lighten melasma without serious adverse effects. However, controlled studies assessing the efficacy and safety of topical tranexamic acid (TA) for the treatment of melasma is limited. OBJECTIVE: To assess in a double blind, randomized, prospective study, the efficacy of topical 5% tranexamic acid versus vehicle for treatment of melasma. METHODS: Twenty-three women with bilateral epidermal melasma enrolled in a split-face trial lasting 12 weeks. Patients blindly applied topical 5% tranexamic acid and its vehicle, to the designated sides of the face twice daily in addition to the assigned sunscreen each morning. Pigmentation and erythema were measured objectively using a mexameter and Melasma Area and Severity Index (MASI), in addition to physician and patient global assessments. RESULTS: Twenty-one patients completed the study. Eighteen out of twenty-three patients (78.2%) showed decrease in the melanin index on either or both sides of the face by the end of 12 weeks compared to baseline. The MASI scores were also significantly reduced on both tested sides. However, lightening of pigmentation induced by TA gel was neither superior nor different (p > 0.05) compared to its vehicle although erythema was significant on the TA-applied site (p < 0.05). CONCLUSIONS: Although lightening of pigmentation was obtained, the results were not significant between the two regimens. However, topical TA produced erythema.

Hydroquinone therapy for post-inflammatory hyperpigmentation secondary to acne: not just prescribable by dermatologists.

Post-inflammatory hyperpigmentation after acne can be as troublesome as the acne itself. Hydroquinone, a tyrosinase inhibitor, in a 4% cream can be used safely twice daily for up to 6 months to treat post-inflammatory hyperpigmentation. The efficacy of this treatment can be enhanced by using a retinoid nightly and a mid-potent steroid, which is applied twice daily for 2 weeks, then at weekends only. Combination creams help with compliance, but often lack the strongest individual ingredients. Because steroids should not be applied to the face for prolonged periods, care should be taken when a hydroquinone cream containing a steroid is chosen. If post-inflammatory hyperpigmentation consists of a few lesions, spot therapy is useful. If post-inflammatory hyperpigmentation consists of many lesions, field therapy is favored. Safety concerns with hydroquinone consist only of occasional irritation, which can be suppressed with topical steroid or a short drug holiday. Physicians should feel comfortable to use hydroquinone without consulting a dermatologist. Key words: hydroquinone; acne; adolescent; post-inflammatory hyperpigmentation.

Avaliação clínica da sensibilidade e efetividade do clareamento em consultório de dentes polpados, com e sem o emprego de fonte de luz: controle de 12 meses / Clinical evaluation of sensitivity and effectiveness of in-office whitening in sounds teeth, with and without the use of light source: 12 months follow-up

Este estudo in vivo analisou comparativamente duas técnicas de clareamento de dentes polpados, quanto ao grau de sensibilidade, mudança de cor e estabilidade do tratamento num período de doze meses. Dez pacientes foram selecionados de acordo com os critérios de inclusão e exclusão, e submetidos ao clareamento em consultório, sendo que o mesmo paciente recebeu os dois protocolos de clareamento. Grupo A (GA): três aplicações de 15 (totalizando 45) do gel de peróxido de hidrogênio (PH) 35% (Lase Peroxide Sensy, DMC Equipamentos Ltda.), nos hemi-arcos inferior e superior esquerdo. Grupo B (GB): três aplicações do gel PH 35% ativado com luz híbrida de LED/laser de diodo (Whitening Lase II DMC Equipamentos Ltda.) por 2, com intervalo de 30 (730), totalizando 2230, nos hemi-arcos inferior e superior direito. A avaliação da cor foi realizada com o espectrofotômetro Vita EasyShade (VITA), sendo a diferença mensurada através do sistema CIE-Lab antes do clareamento, após 24 horas, 1 semana, 6 e 12 meses. A sensibilidade dentária foi avaliada por meio do questionário VAS antes, imediatamente após o clareamento, após 24 horas e 1 semana. Para as variáveis luminosidade (?L) e alteração de cor (?E), ANOVA a dois critérios (período e luz) revelou haver diferenças estatisticamente significantes intra e intergrupos em função dos períodos avaliados (p<0,001). O teste de Tukey (p<0,001) para comparações individuais apontou diferenças significantes intergrupos para os dentes superiores nos períodos de 1 mês, 6 meses e 1 ano com os demais tempos avaliados. Para os dentes inferiores não houve diferenças estatísticas intra e intergrupos (p=0.0821). O GB ativado com luz apresentou, imediatamente após o clareamento, o menor grau de sensibilidade dentária com diferença estatística (p=0,043) em comparação ao GA (sem luz). Os dois protocolos de clareamento com e sem luz avaliados durante 12 meses foram semelhantes quanto a efetividade do clareamento dental. Por outro lado, a utilização...

This study examined in vivo comparison of two techniques for whitening pulp teeth, the degree of sensitivity, color change and stability of treatment over a period of twelve months. Ten patients were selected according to the criteria for inclusion and exclusion, and subjected to in-office bleaching, and the same patient received both protocols whitening. Group A (GA): three applications of 15' (total 45') of hydrogen peroxide gel (PH) 35% (Sensy Lase Peroxide, DMC Equipment Ltd.), Hemi-arches in the lower and upper left. Group B (GB): three applications of the gel 35% PH with light activated hybrid LED / laser diode (Whitening Lase II DMC Equipments Ltda.) By 2 ', with an interval of 30' (7'30"), totaling 22'30", hemi-arches in the lower and upper right. The evaluation was performed color with the spectrophotometer Vita Easyshade (VITA), and the difference measured with the CIE-Lab system before the treatment, after 24 hours, 1 week, 6 and 12 months. The tooth sensitivity was assessed using the VAS questionnaire before and immediately after bleaching, after 24 hours and 1 week. For the variable brightness (?L) and color change (?E), two-way ANOVA (time and light) revealed statistically significant differences within and between groups on the basis of the evaluation period (p<0.001). The Tukey test (p<0.001) for individual comparisons showed significant differences between groups for the upper teeth at 1 month, 6 months and 1 year with the other times evaluated. For the lower teeth no statistical differences within and between groups (p=0.0821). The GB had activated with light, immediately after bleaching, the lowest degree of tooth sensitivity with statistical difference (p=0.043) compared to GA (no light). The two protocols with and without light bleaching evaluated during 12 months were similar in effectiveness of tooth whitening. Moreover, the use of the light source hybrid decreases the time of treatment provided by 50% and less sensitivity postoperative.

Analytic assessment under ultraviolet light of actinic lentigines under bleaching treatment.

BACKGROUND: Actinic (solar) lentigines are melanotic tumors frequently developed during photoaging on the dorsum of the hands. Bleaching (whitening) agents are commonly offered to fade their darker aspect. In general, regular colorimetric methods show poor sensitivity to disclose any bleaching effect. METHOD: The present randomized controlled study on 24 women was designed to objectively assess the clinical efficacy of a combination of bleaching agents on actinic lentigines. In the endeavor of improving sensitivity, the ultraviolet light-enhanced visualization (ULEV) method was used to derive analytical measurements of lentigo areas and darkness. The test product was a commercially available formulation associating glycolic acid, kojic acid, lipohydroxyacid, and a Vitreoscilla extract. The Analysis® Olympus and Adobe Photoshop® quantitative methods were applied to the ULEV pictures. RESULTS: Data indicated a rapid bleaching effect arising as early as after 1 month of daily applications. The effect progressively increased over 3 months of therapy. CONCLUSION: The presently described analytical method appears to be sensitive to document some bleaching effects on actinic lentigines.

"Hot tub" Folliculitis from a nonchlorinated children's pool.

Pseudomonas aeruginosa is common cause of folliculitis following contact with contaminated water. We report a case of pseudomonal folliculitis that occurred after swimming in a children's pool filled with water from a well.