Therefore, efficiency of the curing unit and applying the recommended curing time of the light activated resin based dental materials is very important to protect the patient from potential hazards of residual monomers. Table 4 Mean TEGDMA and BisGMA release (concg/L) from Enamel Loc fissure sealant samples in to Nutlin-3a Mdm2 inhibitor ethanol after 1,3 and 7 days. a,b,c,d,e,f,g,h P<.05. Table 5 Mean TEGDMA and BisGMA release (concg/L) from Filtek Z 250 composite resin samples in to ethanol after 1,3 and 7 days. a,b P<.05.
Mouthguard bleaching is a popular technique for vital tooth bleaching,1 in which either 1.5�C10% hydrogen peroxide or 10�C15% carbamide peroxide are used as bleaching agents.2 Recently, bleaching products containing higher concentrations of carbamide peroxide have been introduced for clinical use.
Controlled mouthguard bleaching procedure is considered relatively safe with regard to systemic effects.3 However; some concerns have been raised about adverse effects of bleaching agents, including irritation of gastric and respiratory mucosa, alteration of the morphology and chemical composition of enamel, dentin and cementum, as well as damage to existing restorations.2,4�C7 Patients who receive mouthguard bleaching procedures may have amalgam restorations on their existing teeth.8 Although bleaching gels are routinely applied to anterior teeth, excessive gel may inadvertently come into contact with amalgam-restored posterior teeth and increase the susceptibility of those amalgam restorations to corrosion and degradation and increase levels of surface mercury.
9 Several in vitro studies have investigated the effect of different bleaching agents, such as carbamide peroxide, on mercury release from dental amalgam.10,11 Rotstein et al assessed the surface levels of mercury and silver of dental amalgam treated with carbamide peroxide using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy analysis conducted by means of SEM (EDX).1 They demonstrated that consistent treatment with carbamide peroxide solution might cause micro structural changes in amalgam surface, possibly increasing the levels of surface mercury and silver.1 Mercury released from dental amalgam during mouthguard bleaching can be absorbed by the oral mucosa, as well as by the respiratory and gastrointestinal tracts, thus increasing the total body burden of mercury, and leading to a variety of systemic toxic effects.
12 The possible detrimental interactions between these alloys and the bleaching agents might be of clinical significance.8 Clinicians must take special care to reduce the release of mercury when using bleaching agents. Considering the issues discussed above and the increasingly high public demand for home and in-office bleaching, the aim of the present study was to evaluate the levels of surface mercury in amalgam specimens treated intermittently with two types of home and in-office Drug_discovery bleaching gels using SEM-EDX.