Marginal microhardness of corroded amalgams: a comparative in vitro study

Patsurakos, Ajis; Moberg, Lars-Erik

doi:10.1111/j.1600-0722.1990.tb00980.x

Cited by 8 publications

(10 citation statements)

References 28 publications

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“…In the present study both the marginal microhardness values and the corrosion rates after imtnersion in the test solution were intermediate to those obtained in a previous Table 5 Mean dissolution of elements (\>,gjml) from three amalgams in 85 mM MaCl solution (8). Asterisks indicate statistically higher values compared to mean values of same amalgam in (8) when aqueous solutions of NaCl and phosphate buffer were used separately.…”

Section: Discessioncontrasting

confidence: 51%

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Corrosion behavior and microhardness of three amalgams

Patsurakos

Moberg

1988

European J Oral Sciences

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– The marginal microhardness of three different types of amalgam was tested after 2 months' immersion in an aqueous solution of NaCl (85 mM) and phosphates (Na2HPO4 100 mM and NaH2PO4 100 mM). Amalgams immersed in distilled water were used as controls. The microhardness tests were conducted at a distance of 50 μm from the margins and at the bulk of each specimen. The solutions were analyzed for Sn, Cu, Zn, Ag, and Hg by means of atomic absorption spectrophotometry (AAS). A statistically significant reduction in the marginal microhardness after immersion in the test solution was found for the conventional and the high‐Cu single composition amalgam but not for the high‐Cu blended amalgam. SEM‐examination of cross‐sections of the amalgams revealed small areas of subsurface grain boundary corrosion, no deeper than 10 μm for all the amalgams. The SEM‐examination of the specimens and AAS analysis of the solutions indicated that the reduction in marginal microhardness was attributed mainly to corrosion of the Cu‐rich phases for the high‐Cu single composition amalgam and to corrosion of the γ2 phase for the conventional amalgam. The phosphates reduced the corrosion of the amalgams in the presence of NaCl. It is concluded that the marginal strength of dental amalgams in a corrosive environment is largely dependent upon their corrosion resistance.

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Section: Discessioncontrasting

confidence: 51%

“…This shortcoming ture (5)(6)(7). In a previous study (8), in vitro decreases the life of the restoration and has corrosion and microhardness measurements been related to secondary caries and bulk were used to compare the marginal behavior fractures (4).…”

mentioning

confidence: 99%

Corrosion behavior and microhardness of three amalgams

Patsurakos

Moberg

1988

European J Oral Sciences

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“…1975). Patsurakos & Moberg (1988, 1990) have reported that copper release was different in the amalgams with high copper content. In the present study it was determined that the copper release in the low copper‐containing amalgams was higher than that of high copper‐containing amalgams.…”

Section: Discussionmentioning

confidence: 99%

“…It is known that the metal release from amalgams can be changed according to the type of test solutions and amalgam type (Patsurakos & Moberg 1988, 1990). Sarkar & Lian (1993) reported that corrosion behaviour changed along with the immersion period.…”

Section: Discussionmentioning

confidence: 99%

“…The concentration of chloride ions in saliva is different from in vitro conditions. Active chewing in the mouth affects the amalgam restorations (Moberg & Oden 1985a;Patsurakos & Moberg 1988, 1990). As a result it is concluded that high copper‐containing amalgams with indium and platinum are more resistant to corrosion according to our results.…”

Section: Discussionmentioning

confidence: 99%

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In vitro corrosion behaviour and microhardness of high‐copper amalgams with platinum and indium

Aydın

Işimer

et al. 1999

J of Oral Rehabilitation

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Samples prepared from Luxalloy, GS-80, Permite-C and Logic and polished after 24 h by traditional methods were stored in polypropylene tubes containing phosphate-buffered saline solutions (pH 3.5 and 6.5) and distilled water. The amounts of mercury, silver, tin, copper, zinc, platinum and indium in the test solutions were determined at the first, second, eighth, 52nd and 78th week by atomic absorption spectrometry. At the end of the eighth week the amalgam samples were removed from solutions and evaluated by Rockwell Super Scial Microhardness tester. Statistically significant low amounts of metal ions were measured for Permite-C containing indium and Logic containing platinum. The microhardness test results showed that there were statistically significant increases in the microhardness of Permite-C and Logic. As a result it was shown that the amalgam samples were affected from corrosion conditions to different degrees. Sample of the Logic group that was stored in distilled water, showed smoother surface properties than other amalgam samples containing high copper. However, it was observed that samples of Permite-C group had the smoothest surface properties.

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Characterisation of secondary metal-bearing phases in used dental amalgam and assessment of gastric solubility

Miler

2017

Environ Geochem Health

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Detailed SEM/EDS investigation of used dental amalgams was carried out in order to characterise morphology and chemical composition of secondary metal-bearing phases resulting from long-term exposure of dental amalgam to oral environment, and assess their solubility in gastric environment. The investigation revealed numerous secondary phases, represented by compositionally and morphologically complex Hg-, Cu-, Sn-, Ag-, Zn-bearing sulphides and oxides/hydroxides, while sulphates and phosphates are scarce. Secondary metal-bearing phases mostly occur at the amalgam/tooth interface; however, some phases were found only on the occlusal surfaces of amalgam. Secondary phases mostly form porous aggregates of minute crystallites and micro- or nanocrystalline crusts. In oral environment, these phases are mostly stable and represent trapping media for dissolved potentially toxic metals released during amalgam corrosion. Simplified PHREEQC calculations of solubility of secondary metal-bearing phases in aqueous environment under conditions similar to those in gastric environment showed that secondary phases are more soluble in gastric environment than in oral solutions, which is mostly due to their forms of occurrence. Secondary phases in gastric environment thus act as secondary sources of potentially toxic metals, particularly Sn, Zn and also Cu, which are released both under reducing and oxidising conditions especially in acidic environment. Only very small amounts of Hg are potentially released and should not represent serious threat. Secondary phases that contribute the most to bioaccessibility of these metals are Sn hydroxychlorides, Sn oxides/hydroxides, Sn sulphates/hydroxysulphates, Sn oxides, Zn sulphides and Cu sulphides (CuS).

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Marginal microhardness of corroded amalgams: a comparative in vitro study

Cited by 8 publications

References 28 publications

Corrosion behavior and microhardness of three amalgams

Corrosion behavior and microhardness of three amalgams

In vitro corrosion behaviour and microhardness of high‐copper amalgams with platinum and indium

Characterisation of secondary metal-bearing phases in used dental amalgam and assessment of gastric solubility

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