过氧化脲牙齿美白剂开发及应用研究进展

过氧化脲可通过持续释放活性氧达到牙齿美白的目的，适用于各种原因引起的着色牙齿的美白。它可同时美白多个牙齿，美白效率高，费用低，使用方便，刺激性小。详细介绍了国内外专利配方及其使用效果；总结了国内外对过氧化脲牙齿美白剂的应用研究和对牙釉质、牙本质的影响；指出了国外研究的发展趋势，结合我国的实际情况对我国开发过氧化脲牙齿美白剂的方向提出了建议。     

过氧化物美白牙膏的稳定性研究

牙齿表面上的色素一方面是由一些外源性带色物质如：咖啡、烟、茶等渗入到牙釉质中遮盖了釉质，降低了釉质的透明度，另一方面是这些物质日积月累沉积在牙齿釉质表面，而令其失去光泽，使牙表面呈现着色。使用含过氧化脲牙膏可以清除这些牙表面的色素，增白牙齿。由于牙膏中的过氧化脲在刷牙时与口腔唾液结合放出活性氧，与牙釉质表面中的色素发生氧化漂白作用，使色素褪色，同样它还可以通过刷牙使活性氧渗透到牙釉质微孔中，也起到牙齿增白作用。牙齿能否增白取决于牙膏中的过氧化脲有效含量及存放期间衰减情况，怎么有效保证过氧化脲中的活性氧及含量(有效成份)是该课题的重要关键所在，同时定期测定和考核过氧化脲活性及氧含量的变化情况也是至关重要的。     

皮肤美白剂进展

从黑色素形成的生理、生化过程的角度探讨了美白剂必须具备的功能和美白剂开发的理论依据。综述了主流及新近研究开发的美白剂的作用机理和功效，指出了值得关注的一些化合物，并提出全美白概念型美白剂、多酶抑制美白剂是以后研究开发的重要方向之一，同时对美白剂二次开发的目的和手段作了阐述。     

美白护龈牙膏的研究及功效验证

通过正交设计，分别筛选出磨擦剂（二氧化硅）、保湿剂（甘油、山梨醇、聚乙二醇（PEG））及黏合剂（羟乙基纤维素（HEC）、羧甲基纤维素钠（CMC）、增稠型二氧化硅）的最佳配方添加量，同时添加具有较好牙齿美白效果的植酸钠和具有养护牙龈的云南白药提取物，研究开发出一款具有美白护龈功效的牙膏。牙膏稳定性考察合格，通过牙膏去除外源性色斑功效评价，结果表明牙膏能有效去除咖啡、红茶、酱油、烟渍引起的牙釉质外源性色斑，具有较好的美白效果。临床功效验证表明，牙膏对牙龈指数和龈沟出血指数有明显的改善作用。此款牙膏原料用量少，成本低，使用方便，美白护龈效果好，为牙膏配方的研究开发提供了一定的研究思路。     

皮肤黑色素形成机理的研究进展及皮肤美白剂的发展现状

黑色素形成机理的研究与美白化妆品的发展历来紧密相连，本文综述了皮肤黑色素的形成机理和主流化妆品美白剂的作用机理。同时，对现有国内市场的美白剂进行了调研及分析，并对美白剂的发展提供了新思路。     

牙齿美白的研究与应用进展

综述了目前口腔护理中牙齿美白的研究现状与应用情况,从原理上对各美白产品及技术进行了归类,同时,对近几年兴起的新型美白产品进行了概述,并指出该类产品在牙齿美白领域具有重大潜力。     

高粘度、多功能过氧化脲洁牙凝胶的制备研究

制备了具有洁牙、护牙、抗菌消炎作用的高粘度、多功能过氧化脲洁牙凝胶。该凝胶无毒、无副作用 ,在口腔应用中粘度稳定 ,避免唾液溶解 ,使洁牙成分持久释放 ,提高洁牙效率。研究了过氧化脲的制备方法 ,所制备的过氧化脲质量分数大于 98%。所制备的齿科材料为粘度 30 0～ 4 5 0Pa .s,pH值 5～ 7的无色透明凝胶 ,含过氧化脲质量分数 6 %～ 2 0 % ,稀释剂 4 0 %～ 80 % ,增稠剂 4 %～ 10 % ,pH调节剂 2 %～10 %及稳定剂、抗过敏剂、护牙剂、调味剂等成分。     

《牙膏生产技术理论》系列讲座 第五讲 牙膏原料技术理论(下)(待续)

正15除渍美白剂除渍美白剂是指添加于牙膏等口腔护理产品,通过日常使用,能够有效去除牙面附着物、牙色斑、牙渍等,提高牙齿白度的功效成分。牙齿变色分为内源性着色和外源性着色。牙齿内源性着色的成因复杂,分为牙萌出前和萌出后,包括氟斑牙、四环素牙、遗传性因素(如遗传性牙本质发育不全)和系统性疾病(如血液系统疾病)等。牙齿外源性着色是由于吸烟、饮茶、喝咖啡及食用有色的食物时,物质被吸附到牙     

一种新型美白牙膏的临床功效评价

该临床研究的目的是通过双盲试验方法来评价高露洁全效加美白牙膏对牙齿的美白效果。与高露洁全效牙膏相比，在高露洁全效加美白牙膏的配方中加入了高效清洁二氧化硅磨料(high cleaning silica，HCS)。受试者来自于加拿大安大略的Mississauga地区，入选时均接受牙齿外源性色斑的基线检查，符合临床试验方案要求的受试者按年龄、性别和牙齿颜色(外源性)随机分成两个治疗组。受试者用软毛牙刷每天早晚各一次，用指定的牙膏刷牙一分钟。6周后每个受试者再接受一次牙龄外源性色斑检查。共有93名受试者完成了整个研究。结果经统计学处理表明：高露洁全效加美白牙膏与高露洁全效牙膏相比，在减少牙齿外源性色斑面积和降低牙齿外源性色斑深度上有显著的差异。     

口腔护理产品不只是如贝皓齿

当宝洁在2001年大量推出Crest Whitestrip（佳洁士美白牙贴产品）时，消费者蜂拥而至到商店，化费30多美元来购买这种能在家中美白其牙齿、便捷而有效的方法。于是这股热潮就开始了。很快，商店货架上就陈列了那些承诺能在两周或更短时间内美白牙齿的牙贴、凝胶和液体产品，消费者又纷纷抢购。尽管牙齿美白类产品的销售在2004年有所下降．不过消费者仍然期望通过日常口腔护理产品的使用来期待更洁白的微笑。除了市场上的美白套裴，牙膏、牙刷和漱口水也比以前销售的同类产品提供了更高水平的牙齿美白效果。但是，消费者依旧希望更多。     

Über die Charakterisierung der Carbamidextrakte aus einem Erdölparaffingatsch

Characterization of Carbamide Extracts from Petroleum Wax The authors report the properties of carbamide extracts which were recovered from petroleum wax by combination of various methods of separation. The physical properties of the fractions of carbamide extracts were determined and compared with those of other products. It could be shown that by virtue of their varying reaction behaviour towards carbamide, the solid hydrocarbons can be classified into groups. The fractions which form adducts only in the presence of n-paraffins possess properties similar to those of micro-waxes.     

Some theoretical and practical aspects of polyester whitening from the wash bath

Uptake of fluorescent whitening agents from aqueous and organic systems by polyester fibers and films under various conditions was investigated. Different factors influencing the correlation between uptake of the fluorescent whitening agents and their performance in laundry liquors are discussed on the basis of the presented data. The results indicate that fluorescent whitening agents normally used for whitening other synthetic fibers can also have valuable additional effects on polyester. Furthermore the results are discussed in terms of the possible mechanisms of whitening.     

Fluorescent whitening agents—a survey (1974-82)

This survey presents a comprehensive coverage of the literature on fluorescent whitening agents for the period 1974 to mid-1982. It is intended to serve researchers in the field by providing an up-to-date summary of the published literature on the synthesis, textile applications and analysis of fluorescent whitening agents. The survey does not cover the use of fluorescent whitening agents as additives for soaps and detergents.The latter part of the survey describes the light fading reactions of five technologically important classes of fluorescent whitening agent. Recent progress in understanding the photochemical processes that are responsible for fading, and the factors that influence the light stability of fluorescent whitening agents in a polymeric environment, are summarized.     

Amineborane: a unique reductive bleaching agent that protects cystine disulphide bonds in keratins

This paper reports a new application for amineboranes in the bleaching of wool, a typical example of keratin fibre. It has been found in this investigation that amineboranes are unique reductive bleaching agents that do not attack cystine disulphide bonds in wool keratin and do not impart permanent set to the fibre during bleaching. Selected amineborane compounds can be used in conjunction with oxidative agents such as hydrogen peroxide in aqueous media to further enhance the whitening effect and prevent disulphide bond disruption in keratins. The results of this study have suggested that the researched technology outperforms existing bleaching methods on a number of levels and may be an important step towards a new commercial bleaching technology.     

美白化妆品添加剂效能的实验研究

利用体外,体内实验方法对美白添加剂及配方进行筛选和评估,通过观察美白添加剂对酪氨酸酶的抑制作用,对Ｂ１６细胞活力及黑素生成的影响,结合临床受试者实验,结果表明,根据黑素生成理论的新的认识所复配的美白添加剂效果较为理想。     

高效液相色谱法测定小麦粉中增白剂过氧化苯甲酰

本文提出了用高效液相色谱分离和测定小麦粉中增白剂过氧化苯甲酰的新方法。用水为溶剂通过超声提取面粉中的过氧化苯甲酰,在酸性环境中用铁粉使之还原为苯甲酸,然后在中性环境下用高效液相色谱进行测定,具有良好的准确度和再现性。     

Nitrogen-Doped Titanium Dioxide Mixed with Calcium Peroxide and Methylcellulose for Dental Bleaching under Visible Light Activation

The available tooth whitening products in the market contain high concentrations of hydrogen peroxide (H₂O₂) as an active ingredient. Therefore, in order to curb the high H₂O₂ concentration and instability of liquid H₂O₂, this study evaluated the efficacy and cytotoxicity of the bleaching gel composed of 10% calcium peroxide (CaO₂) and visible-light-activating nitrogen-doped titanium dioxide (N-TiO₂) with methyl cellulose as a thickener. Extracted bovine teeth were discolored using coffee and black tea stain solution and were divided into two groups (n = 6). Bleaching was performed thrice on each tooth specimen in both the groups, with one minute of visible light irradiation during each bleaching time. The CIELAB L*a*b* values were measured pre- and post-bleaching. The N-TiO₂ calcinated at 350 °C demonstrated a shift towards the visible light region by narrowing the band gap energy from 3.23 eV to 2.85 eV. The brightness (ΔL) and color difference (ΔE) increased as bleaching progressed each time in both the groups. ANOVA results showed that the number of bleaching significantly affected ΔE (p < 0.05). The formulated bleaching gel exhibits good biocompatibility and non-toxicity upon exposure to 3T3 cells. Our findings showed that CaO₂-based bleaching gel at neutral pH could be a stable, safe, and effective substitute for tooth whitening products currently available in the market.     

Electrochemical behavior of non-precious dental alloys in bleaching agents

Corrosion behavior of dental alloys in artificial saliva containing different concentrations of hydrogen peroxide, carbamide peroxide and fluoride ions was studied using electrochemical technique. The alloys have been arranged according to its corrosion resistance in the hydrogen peroxide and carbamide peroxide as follows: wiron99 > wirolloy > wironit. Alloys suffer less corrosion rates in presence of carbamide peroxide than hydrogen peroxide. The effect of CH₆N₂O₃ on the corrosion is less than the effect of H₂O₂ and this is due to the presence of centers rich by electrons such as nitrogen and oxygen in CH₆N₂O₃. Nitrogen and oxygen adsorbed on the alloy surface forming protective layer isolate it relatively from the corrosive medium. The order of increasing resistivity of the alloys in fluoride solution is as follows: wironit > wiron99 > wirolloy. SEM for the three alloys in artificial saliva containing 0.015 M F⁻ shows that wironit has less corrosion compared to the two other alloys and this agrees with the results obtained from potentiodynamic polarization curves and Nyquist impedance diagrams.