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Benzoyl Peroxide
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
Benzoyl peroxide is an organic compound in the peroxide family and one of the most important in terms of applications. In medicine, benzoyl peroxide is used as a topical treatment for acne, either in combination with antibiotics or as a single agent; it has also been used in burns and for the treatment of leg ulcers. Like most peroxides, benzoyl peroxide is a powerful bleaching agent. Contact with fabrics or hair can cause permanent color dampening almost immediately; even secondary contact can cause bleaching. Because of this quality, benzoyl peroxide is also used for bleaching flour and cheese in the food industry, bleaching of hair and for teeth whitening. Other applications include the cross-linking of polyester resins, an initiator for polymerization of (meth)acrylates in artificial nail material (1), in fillers, putties, plasters, modelling clay, adhesives and sealants, biocides (e.g. disinfecttants, pest control products), coating products, finger paints and inks and toners. Benzoyl peroxide is found naturally in cereals and cereal products (29).
Hypopigmentation from chemical and physical agents
Published in Electra Nicolaidou, Clio Dessinioti, Andreas D. Katsambas, Hypopigmentation, 2019
Katerina Damevska, Igor Peev, Ranthilaka R. Ranawaka, Viktor Simeonovski
Hydroquinone is the most commonly used bleaching agent and the gold standard for treatment of hyperpigmentation. Chronic adverse effects include exogenous ochronosis, cataract, colloid milia, nail pigmentation, impaired wound healing, and fish odor. There are infrequent reports of confetti-like, 1–3 mm hypopigmented macules.7
Manufacture of Glycerine from Natural Fats and Oils
Published in Eric Jungermann, Norman O.V. Sonntag, Glycerine, 2018
Crude glycerine solutions obtained from any of the above processes are generally bleached to remove additional impurities. The most frequently used bleaching agent is activated carbon, but certain clays have also been employed with success. Color bodies, primarily pigments and residues from the fat or oil originally processed, are effectively removed by these bleaching treatments. Some residual fatty material, especially the odiferous low-molecular-weight acids, may also be removed by absorption onto bleaching agents. Bleaching operations are normally performed at 165 to 185°F to facilitate filtration while minimizing any thermal degradation. Other chemical bleaching treatments are generally not useful on glycerine due to the relative ease with which the glycerol itself can be degraded or reacted, but such methods have been described in the literature [6].
Analysis of enamel structure and mineral density after different bleaching protocols using micro-computed tomography
Published in Acta Odontologica Scandinavica, 2020
Derya Surmelioglu, Eda Didem Yalcin, Kaan Orhan
Within all these results, the group that caused the least change in superficial enamel in all structural change indexes was Er,Cr:YSGG group. Er,Cr:YSGG laser represents affinity to hydroxyapatite and water more than other laser systems [10]. This feature provides safety on bleaching because laser energy leads to the heating of bleaching agent which contains a high percentage of water. In this way, it is not transmitted to deeper layers of tooth structures [43]. The diode laser, which has a 980 nm wavelength, is absorbed by water more than other wavelengths [11]. However, because the diode laser is barely absorbed by hydroxyapatite, leading to minimal transmission and scattering of the laser’s light, the anticipation of laser-induced enamel surface changes seems unreasonable [52]. Thus, it can be stated that preferring Er,Cr:YSGG seems safer than diode for the activation of bleaching agents.
Anti-melanogenic effects of extracellular vesicles derived from plant leaves and stems in mouse melanoma cells and human healthy skin
Published in Journal of Extracellular Vesicles, 2020
Ruri Lee, Hae Ju Ko, Kimin Kim, Yehjoo Sohn, Seo Yun Min, Jeong Ah Kim, Dokyun Na, Ju Hun Yeon
Melanin, a key component of the pigmentary systems of human hair, eyes and skin, is produced by melanocytes through a process called melanogenesis [1]. Abnormal accumulation of melanin causes dermatological problems such as freckles, solar lentigo and melasma, as well as cancer and vitiligo [2–5]. Therefore, regulating melanogenesis is a crucial strategy in the treatment of hyperpigmentary disorders [6]. For example, hydroquinone, a hydroxyphenolic chemical compound that interferes with TYR activity, is used as a skin-bleaching agent in the cosmetic industry. However, hydroquinone may cause side effects such as contact dermatitis and exogenous ochronosis [7–9]. Tretinoin is another synthetic agent that inhibits TYR activity, but its use is associated with a high frequency of oedema or irritation [10].
Clinical and patient reported outcomes of bleaching effectiveness
Published in Acta Odontologica Scandinavica, 2018
Eva Klaric Sever, Zrinka Budimir, Matea Cerovac, Mario Stambuk, Matej Par, Dubravka Negovetic Vranic, Zrinka Tarle
Current literature lacks the comprehensive evaluation of a bleaching treatment. Most studies have been focused on physical properties of different bleaching treatments, such as bleaching effectiveness measured in CIELab colour space, but ignored the perceptions of patients themselves. Tooth colour is considered a critical factor in influencing patient satisfaction with bleaching treatment; however, only a limited number of studies examined patient satisfaction with different aspects of a bleaching treatment [14,15]. Bleaching efficacy and patient satisfaction with the treatment are not necessarily related [16]. This study adds to the literature by comparing the clinical outcomes, defined herein as objective clinical conditions or results used to assess the efficacy of bleaching treatment [17] (e.g. overall change in tooth colour, change in tooth lightness, yellowness, etc.), with the perceptions of patients themselves. Different bleaching procedures and concentrations of bleaching agent were used: two in-office bleaching treatments with high concentrations of HP, namely Boost (40% HP) and Dash (30% HP), and at-home Bite&White treatment with lower concentration of HP (6%). We investigated the medium-term effects of bleaching, up to 6 months after the bleaching treatment. The tooth colour was not expected to be stable in this period of time after the treatment. As eating, drinking and smoking habits may confound the effects of bleaching (i.e. the stability of tooth colour) [5], our study examined those factors as well.