Disease relevance of Thenardol

• Acute toxicity of carbamide peroxide and a commercially available tooth-bleaching agent in rats [1].
• An exposure limit based on the lowest observed effect level (15 mg carbamide peroxide/kg body weight) and a safety factor of 100 were established and utilized in a risk assessment which indicated that daily human exposure during a bleaching procedure may come close to or even exceed this limit [1].
• Urea hydrogen peroxide (UHP) at a concentration of 30 to 32 mmol/liter reduced the numbers of five Lactobacillus spp [2].
• Simultaneous bleaching of vital teeth and an open-chamber nonvital tooth with 10% carbamide peroxide [3].
• The data suggest that these products are clinically equivalent for tooth whitening; however, the product containing 5% carbamide peroxide was associated with less tooth hypersensitivity after 1 week of application [4].

High impact information on Thenardol

• Carbamide peroxide gave dose-dependent ulcerations of the gastric mucosa, with the 15 mg/kg body weight as the lowest observed effect level [1].
• Cytotoxicity and dentin permeability of carbamide peroxide and hydrogen peroxide vital bleaching materials, in vitro [5].
• After 2 h, mean respirations per min of animals receiving the tooth whitener Quik Start (contains 35% carbamide peroxide) decreased from 169 to 55, and body temperature decreased from 38.4 to 34 degrees C. Other distress signs included: labored breathing, loss of righting reflex, partial eye closure, bloody urine, and incontinence [6].
• This study evaluated the histological changes in dental pulp after nightguard vital bleaching with 10% carbamide peroxide gel [7].
• This clinical study compared the effectiveness of bleaching non-vital teeth with an open pulp chamber during bleaching using 10% carbamide peroxide compared to the modified walking bleach technique and extracoronal bleaching [8].

Chemical compound and disease context of Thenardol

• The purpose of this article is to provide an overview of the role of one oxygenating agent, carbamide peroxide in glycerol solution, in the prevention and control of periodontal disease [9].

Biological context of Thenardol

• Oxidative stress aspects of the cytotoxicity of carbamide peroxide: in vitro studies [10].
• This paper will review the history of using peroxides for tooth whitening, the toxicology of H2O2 and carbamide peroxide, and available information on the safety of whiteners [11].
• The study showed that pre-treatment of enamel with CP followed by fluoridation does not improve erosive resistance [12].
• Carbamide peroxide bleaching of teeth with dentinogenesis imperfecta discoloration: report of a case [13].
• None of the cases revealed a promoter or enhancer capacity of carbamide peroxide [14].

Anatomical context of Thenardol

• There has been recent concern about the inadvertent exposure of dentin with patent tubules as well as gingiva to bleaching systems containing 10-15% carbamide peroxide or 2-10% hydrogen peroxide for more than a few minutes [5].
• CONCLUSION: Carbamide peroxide (10%) caused an augmentation in the proliferative activity within the basal and parabasal layers of the gingival epithelium, resulting in a change in this tissue's morphometry [15].
• The cytotoxicity of carbamide peroxide, as related to oxidative stress, was evaluated in vitro with several human cell lines, including Smulow-Glickman (S-G) gingival epithelial cells [10].
• Previous work in our laboratory showed that a bleaching agent, which generates approximately 3% H2O2 from carbamide peroxide, was toxic to human gingival fibroblasts in vitro, but that the toxicity was abolished by treatment with the H2O2-destroying enzyme catalase [16].
• MATERIALS AND METHODS: Five extracted human incisors were treated with 10% carbamide peroxide (Opalescence) for 4 h/day for 1 week and were compared with non-bleached teeth for oxygen, calcium, and phosphorus relative concentration using EDS [17].

Associations of Thenardol with other chemical compounds

• The carbamide peroxide gels were different in pH and fluoride content [18].
• The specimens were treated with 10% carbamide peroxide gel (8 h) and subjected twice to remineralization for 2 h in artificial saliva and demineralisation for 90 s in 1% citric acid, pH 2 [18].
• OBJECTIVES: The aim of the study was to compare the gingival health benefits of a thiocyanate/carbamide peroxide toothpaste to that of a triclosan toothpaste in home use [19].
• The potency of carbamide peroxide was related to its hydrogen peroxide component rather than to carbamide, was eliminated in the presence of exogenous catalase, and was enhanced in the presence of aminotriazole, an inhibitor of cellular catalase [10].
• Significant reduction in sulfur levels occurred only in the cementum following treatment with CP and SP [20].

Gene context of Thenardol

• A three-cell, randomized, parallel, investigator-blinded clinical trial was conducted to compare the efficacy and safety of three professional at-home tooth whitening systems, including Crest Professional Whitestrips (6.5% H2O2), Day White 2 (7.5% H2O2) and Nite White Excel 2 (16% carbamide peroxide equivalent) [21].
• Effects of a bleaching agent containing 35% carbamide peroxide on the immunolocalization of cyclin D and p16 [22].
• This study evaluated the effects of 35% carbamide peroxide (Opalescence Quick) and 35% hydrogen peroxide (Opalescence Xtra) on the surface finish of four tooth-colored restorative materials (Spectrum TPH, Dyract AP, Reactmer and Fuji II LC) [23].
• The hardness of resin-modified glass-ionomer cements, hybrid, polyacid-modified and PRG composites is therefore not significantly affected by the use of 35% carbamide peroxide and 35% hydrogen peroxide in-office tooth whiteners [24].
• The two products were the test toothpaste (RCP) containing 0.5% SCN- (rhodanide), carbamide peroxide (equivalent 0.1% H2O2), and 1450 p.p.m. fluoride, and a control toothpaste (Colgate Total) containing 0.3% triclosan, 2.0% polyvinyl methyl ether maleic acid (PVM/MA), and 1450 p.p.m. fluoride (Triclosan) [19].

Analytical, diagnostic and therapeutic context of Thenardol

• The present study evaluates the acute toxicity of a commercially available tooth-bleaching agent and carbamide peroxide, which is the active bleaching ingredient [1].
• ZT was not affected by bleaching treatment, while FT was significantly roughened after one week of bleaching with 15% CP compared to the control group [25].
• Qualitative comparisons of resin tags present in the bleached and unbleached specimens using scanning electron microscopy (SEM) revealed few, thin and fragmented resin tags when 38% hydrogen peroxide and 10% carbamide peroxide were used [26].
• METHODS: The front teeth of 30 subjects were bleached at home with 10%, 17% or 0% (control) carbamide peroxide for 1 week in a double-blind study design [27].
• METHODS: 2x2x20mm bovine dentin specimens were immersed in the bleaching agents to simulate overnight (10 or 15% CP, 6h daily, 2 weeks), exaggerated overnight (10% CP, 6h/day, 5 days/week, 2 months), daytime (6.5 or 7.5% HP, 1h daily, 3 weeks) and in-office (35% HP, 1h/day, 2 days/week, 3 weeks) treatment protocols [28].

References