Galvanic Degradation of Amalgam Restorations

Mateer, R.S.; Reitz, Clair D.

doi:10.1177/00220345720510060601

Cited by 13 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Corroded phases in or near the indentations may be more easily deformed during compression of the diamond indentor than uncorroded phases. MATEER & REITZ (17) have also reported that the Knoop hardness of corroded portions of amalgam restorations was lower than that of uncorroded regions.…”

Section: Discussionmentioning

confidence: 96%

Marginal microhardness of corroded amalgams: a comparative in vitro study

Patsurakos

Moberg

1990

European J Oral Sciences

View full text Add to dashboard Cite

– One conventional and two high‐Cu amalgams were tested for marginal microhardness after 2 months' corrosion in an 85 mM NaCl solution. Amalgams immersed in 200 mM phosphate buffer solution were used as controls. The microhardness tests were conducted on cross‐sections of the amalgams 50μm from the surface edges. The microstructure of the amalgams was studied in SEM and the amounts of Sn, Cu, Zn, Ag, and Hg dissolved in the solutions were analyzed with an atomic absorption spectrophotometer. For the amalgams immersed in the NaCl solution the depth of corrosion after 2 months was between 50 and 400μm. The specimens immersed in the phosphate solution showed no signs of subsurface corrosion. The marginal microhardness of all the amalgams was reduced after corrosion in the NaCl solution. The greatest microhardness in both the uncorroded and corroded states was shown in the two high‐Cu amalgams. The reduction in marginal microhardness after corrosion can probably be attributed mainly to degradation of the gamma‐2 phase for the conventional amalgam and to degradation of the η′ phase for the two high‐Cu amalgams.

show abstract

Section: Discussionmentioning

confidence: 96%

Marginal microhardness of corroded amalgams: a comparative in vitro study

Patsurakos

Moberg

1990

European J Oral Sciences

View full text Add to dashboard Cite

show abstract

“…Over a period of time corrosion progresses from interfaces toward the center of the restoration, reducing hardness and embrittling the matrix structure by molecular disintegration of the γ 2 phase. 14,21,29,31,37 Chloride ions in saliva, food and drinks play an essential role in the corrosion process and the deposition of metallic salts.…”

Section: Corrosion Products Of Dental Amalgammentioning

confidence: 99%

“…Typically Sn was the element that was 6 found in dentin in all dentin penetration studies. 9,[18][19][20][21][22][23][24][25] Mateer and Reitz 21 detected low Hg and Ag content in blackened dentin, but the Sn content in dentin adjacent to amalgam was about as …”

mentioning

confidence: 97%

Penetration of amalgam constituents into dentine

Scholtanus

Özcan

Huysmans

2009

Journal of Dentistry

View full text Add to dashboard Cite

OBJECTIVES: Amalgam restorations are replaced by adhesively placed composite resin restorations at an increasing rate. After the removal of amalgam dentine often shows marked dark discoloration that is attributed to the penetration of corrosion products from overlying amalgams. It is questioned whether penetration of metals into dentine affects the dentine as a substrate for adhesive procedures. This study has been performed to clarify the origin of dark discoloration of dentine by metals from amalgam with special regards to corrosion products. METHODS: A review of the literature has been performed using Medline database. As keywords dentine and amalgam, subsequently combined with penetration, interface, crevice, interaction, corrosion, were used. This was followed up by extensive hand search using reference lists of relevant articles. RESULTS: Data in the literature have been gathered from extracted amalgam filled teeth and from artificially aged amalgam filled teeth. Corrosion studies have been performed in vivo aged teeth as well as in vitro. Sn is the main element, followed by Zn and Cu, that is consistently found in dentine underneath amalgam, as well as in amalgam corrosion products and in marginal seal deposits. Penetration of elements from amalgam has only been observed in discolored and in demineralised dentine. CONCLUSIONS: Darkly discolored dentine as found underneath amalgam restorations contains amalgam corrosion products and is demineralised. Therefore it must be considered a different substrate for clinical procedures than sound dentine. Penetration of Amalgam Constituents into Dentin ABSTRACTObjective: Amalgam restorations are replaced by adhesively placed composite resin restorations at an increasing rate. After removal of amalgam, dentin often shows marked dark discoloration that is attributed to penetration of corrosion products from overlying amalgams. It is questioned if penetration of metals into dentin effects the dentin as a substrate for adhesive procedures. This study has been performed to clarify the origin of dark discoloration of dentin by metals from amalgam with special regards to corrosion products. Methods:A review of the literature has been performed using Medline database. As keywords dentin and amalgam, subsequently combined with penetration, interface, crevice, interaction, 2 corrosion, were used. This was followed up by extensive hand search using reference lists of relevant articles.Results: Data in the literature have been gathered from extracted amalgam filled teeth and from artificially aged amalgam filled teeth. Corrosion studies have been performed in vivo aged teeth as well as in vitro. Sn is the main element, followed by Zn and Cu, that is consistently found in dentin underneath amalgam, as well as in amalgam corrosion products and in marginal seal deposits. Penetration of elements from amalgam has only been observed in discoloured and in demineralised dentin. Conclusions:Darkly discoloured dentin as found underneath amalgam restorations contains amalgam cor...

show abstract

“…In conventional dental amalgams the corrosion process may cause the y2-phase to decompose more or less completely with time [Jorgensen, 1967;Mateer and Reitz, 1972;Holland and Asgar, 1974], The cor rosion combined with a high porosity level in the amalgam [Schoch and Loebich, 1955;Jorgensen et al, 1966] may allow fluoride ions to leach also from the inner parts of a fluoride-containing amalgam and to react with the surrounding tooth substance [Min oguchi et al, 1967;Forsten et al, 1976]. In vitro studies indicate an increased rate of corrosion after the addition of stannous fluoride to the alloy [Stoner et al, 1971;Hurst and von Fraunhofer, 1978].…”

mentioning

confidence: 99%

Artificial Caries-Like Lesions around Conventional, Fluoride-Containing and Dispersed Amalgams

Heintze¹,

Mörnstad²

1980

Caries Res

View full text Add to dashboard Cite

The study was undertaken to evaluate differences in development of caries-like lesions (wall lesions) around three principally different amalgams (conventional, fluoride-containing and dispersed) under standardized conditions. Amalgam restorations were made on sound buccal and lingual surfaces of extracted premolars. After 10 weeks in an acidified gelatin gel the teeth were sectioned through the restorations and planoparallel ground sections were produced. The enamel surrounding the restoration was studied by polarized light microscopy after imbibition with quinoline (n = 1.62). It was found that the depth of the wall lesion and the extent of demineralized enamel were significantly less around the fluoride-containing amalgam than around the other two. Although not always statistically significant, the largest extent of demineralization was seen in wall lesions surrounding the dispersed amalgam. The number, depth and extent of wall lesions were significantly smaller in the cervical part of the cavities than in the coronal part. Signs of intermediate remineralization processes (presence of dark zones) were most often seen in relation to the fluoride-containing amalgam. These findings are discussed in relation to other differences between the amalgams, such as sealing property and corrosion proneness.

show abstract

Galvanic Degradation of Amalgam Restorations

Abstract: Amalgam restorations in contact with saliva and tissue fluid act as concentration cells. The galvanic current is associated with selective attack of the γ 2 phase and loss of mechanical properties. Tin is deposited in the underlying dentin. Cavity liners do not stop the degradation.

Cited by 13 publications

References 4 publications

Marginal microhardness of corroded amalgams: a comparative in vitro study

Marginal microhardness of corroded amalgams: a comparative in vitro study

Penetration of amalgam constituents into dentine

Artificial Caries-Like Lesions around Conventional, Fluoride-Containing and Dispersed Amalgams

Contact Info

Product

Resources

About