The mechanism of gingiva metallic pigmentations formation

Abstract

The occurrence of blue-grey areas in the soft tissue represents one of the problems affecting patients whose teeth have been restored using metallic materials. It is generally accepted that it is caused by mechanical penetration of a metallic material into the soft tissue. Several facts indicate that this mechanism is not general. The aim of the study was to determine an alternative mechanism of the origin of pigmentations, based on the corrosion interaction of metallic materials used in prosthodontics with the oral environment. The study was comprised of an analysis of pigment particles, determination of exposure conditions of metallic materials in vivo and laboratory evaluation of corrosion properties of the studied materials. Particles containing silver, sulphur and/or selenium could be seen in ultra-thin sections in the lamina propria gingivae. Comparison of the corrosion laboratory results with the results of in vivo measurements indicated the intensification of corrosion under these conditions. Amalgams and silver-containing alloys used for teeth restorations may release silver under the conditions of the oral cavity. The formation of soluble silver compounds in the sulcular area or in a crevice between the crown and the cast post-and-core reconstruction facilitates their transport to the soft tissue and subsequent deposition.

Clinical Characteristics of Abutment Teeth with Gingival Discoloration

“…The same type of alloy for the fabrication of cast dowels and FPRs was used in this study. In this way, the possible electrochemical interaction of different metals and the development of corrosion as one of the causes of gingival discoloration were eliminated . Gingival discoloration usually has occurred as a result of the accidental displacement of metal particles into the oral mucosa during dental treatments that involved amalgam or by direct contact between tissue and dental amalgams.…”

“…In most cases, gingival discoloration (GD) has been observed after final cementation of fixed prosthetic restorations, and its presence negates any positive effect of using highly esthetic materials in dental prosthetic therapy. Gingiva pigmentation was found even in the case of a tooth treated by cast post‐and‐core made of silver alloy covered by a polymeric crown . The surgical removal of the stained gingiva may require a new crown fabrication, while the laser removal of gingival staining has proven somewhat successful .…”

Tatuagem extensa por amálgama em mucosa gêngivo-alveolar

“…4 In some cases, this pigmentation may occur by interaction of the oral mucosa with corrosion of metallic materials, especially through release of silver from the amalgam alloys. 5 The usual clinical aspect of amalgam tattoo lesions is a blue, black or gray stain, measuring from 0.1 to 2 cm, that affects mainly the gingival and alveolar mucosa. 4 The amalgam tattoo diagnosis is simple, generally based on clinical observation associated with the presence or history of amalgam fillings removal.…”

Oral diseases associated with fixed prosthodontic restorations

“…These pigmented regions may occur due to other released metals such as silver, copper, palladium, and gold. Joska et al5 reported finding silver and copper in the root of a tooth restored with a gold-based crown. Released metals form soluble compounds in the gingival sulcus, which facilitates their transport and deposition into underlying soft tissues 5…”