Effects of In-Office and Home Bleaching Gels on the Surface Mercury Levels of Dental Amalgam

Abstract

Objectives:The aim of this study was to evaluate the effect of different in-office and home bleaching gels on the surface mercury levels of dental amalgam.Methods:Sixty disk-shaped amalgam specimens (GS-80, SDI- Australia) were prepared and randomly divided into the following treatment groups: 1. Distilled water (control); 2. 15% home-bleach carbamide peroxide (Opalescence PF, Ultra dent, USA) applied for 6 h/day for 3 weeks; and 3. 35% in-office bleach carbamide peroxide (Opalescence Quick, Ultradent) applied for 30 min/week for 3 weeks. Levels of mercury were measured as weight percentages using an energy dispersive x-ray micro-analyzer detector connected to an electron microscope. Data was analyzed using one-way ANOVA and a post hoc Tukey tests (P<.05).Results:There were no significant differences between the surface mercury levels measured following treatment with the tested home-bleach and in-office bleach products (P=0.71). However, both materials yielded significantly more mercury levels than that of the control group (P<.001).Conclusions:The tested bleaching products significantly elevated the surface mercury levels of amalgam in vitro.

Qualitative and quantitative analysis of Mercury ions on the surface of amalgam restorations after home bleaching

“…These authors state that prolonged treatment (more than 14 days) with bleaching agents can promote microstructural changes in the amalgam surfaces, possibly resulting in increased patient exposure to toxic byproducts. Similar results were observed by Oskoee et al [13] who evaluated the effect of CP at 15% applied for 6h/day and observed that Hg levels were significantly higher than control group. At 16% and 30% CP concentrations, Gurgan et al [23] also founded an increase in the Hg release in the samples tested.…”

“…Considering dental amalgam restorations, some studies have shown that the exposure of amalgam to bleaching agents causes an increase in Mercury (Hg) levels on the amalgam surface [12,13], as well as an additional Hg release [14][15][16][17]. Besides, a variation in the Hg release was found among the different types of amalgam exposed to the bleaching agent [15,16].…”

The effect of tooth bleaching on the shear bond strength of orthodontic brackets using self-etching primer systems

“…Most tooth bleaching procedures are safe and well-accepted for the treatment of this esthetic problem, as they do not require any reduction in tooth structure. [3][4][5][6][7] The first condition of orthodontic treatment is bonding the orthodontic brackets to tooth surfaces. However, this step is temporary, because the brackets are removed after active treatment, 8 and maintaining a sound, unblemished enamel surface after debonding is the clinician's primary goal.…”

Study of the hydrogen peroxide based whitening gel on the corrosion of dental metallic alloys

“…The first esthetic treatment using bleaching agents was reported at the end of 19 th century [2,3]. In our time, whitening process consists in discoloring dentition by exposing it to various oxidizing materials, such as: hydrogen peroxide (H 2 O 2 ) [4][5][6][7][8][9] or H 2 O 2 releasing agents (i.e., carbamide peroxide (CP) [2,[9][10][11][12], and sodium perborate) over a period of time, in order to obtain a lighter color of teeth. CP is a very unstable compound and in contact with tissues and saliva will immediately degrade into about onethird H 2 O 2 and two-thirds urea, being in fact a source of H 2 O 2 [6,13].…”

“…In practical life, bleaching agents may come into contact with restorative materials, particularly when using mouth guard bleaching or home kits [4] causing undesirable changes, such as softening and degradation by wear and corrosion of the teeth and/or restorative materials [10,13] prosthetic and implant systems [15]. In this context, extensively research were performed in order to evaluate the surface properties and/or surface alterations of different esthetic restorative materials by different methods, such as: surface roughness measurements [2,4,11]; surface topography evaluation by scanning electron microscopy (SEM) [2,8,11] or by atomic force microscopy (AFM) [7]; profilometric analysis [12]; determination of the alterations in atomic weight by energy dispersive X-ray spectroscopy (EDS) [2,10] or by X-ray photoelectron spectroscopy (XPS) [9]; metal ions release from dental alloys by inductively coupled plasma-mass spectrometry (ICP-MS) [4]; crystallinity index analysis by Raman spectroscopy [5,7]; color measurements by spectrophotometry [5,7]. The corrosion parameters obtained by using electrochemical techniques of investigation of dental metallic alloys in contact with whitening agents are related to the biocompatibility and long-life of different restorative, prosthetic and/or implant systems [4].…”