Monitoring of selenium in oral cavity argyria - a clinical and microscopic study.

OBJECTIVE: Argyria is generally classified as localized or generalized condition. Distinct pigmentation of the oral mucosa in the vicinity of amalgam fillings is often referred to as amalgam tattoos. Pigmented areas can also be associated with silver-containing corrosion products of dental alloys used for prosthetic restorations. Silver-containing electron dense particles (Ag-EDPs) are frequently found in pigmented areas. We attempted to correlate results of the elemental composition of Ag-EDPs with excerpts from health profiles of our study paticipants. DESIGN/SETTING: Eight patients with diagnosed signs of localized argyria were investigated in this study. Biopsies from distinctly pigmented gingival areas were subjected to histological examination, electron microscopy and x-ray microanalysis. RESULTS: Elemental composition of Ag-EDPs determined by x-ray microanalysis showed mainly silver in combination with sulfur or selenium or a combination of both chalcogens. Elemental analyzes results of Ag-EDPs were analyzed along with excerpts from the patient's clinical records. Two patients with low or undetectable selenium in the Ag-EDPs suffered from autoimmune thyroiditis, Parkinson's disease, bronchial asthma, and allergies to molds, pollen and dust. CONCLUSIONS: We suggest that selenium in Ag-EDPs is a product of the detoxification process for Ag(+) ions in gingival tissue and that it may reflect the availability of endogenous selenium for physiological processes in the human body. Its presence or absence might thus be used as another marker of a patient's health status.

The mechanism of gingiva metallic pigmentations formation.

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.

Metallic pigmentation of human teeth and gingiva: morphological and immunological aspects.

The composition of metallic pigmentations in gingiva and dental roots was determined by means of transmission electron microscopy with energy dispersive x-ray microanalysis. The systemic immune response to the metals found in the oral cavity was evaluated in 10 patients by using a modified lymphocyte proliferation test. Immunological results were compared with a group of five controls without metallic materials and pigmentation. Dense particles of various shapes and sizes, as well as of diverse extracellular and intracellular localization patterns, were detected in the pigmented lamina propria gingivae. Metallic deposits consisted predominantly of silver accompanied by selenium or sulfur or both. Besides, Ag, Au, Cr, Ni, Fe, Hg, Cu, and Ti were identified in dentinal tubules of teeth reconstructed with dental alloys. Nine patients with metallic pigmentations had a positive lymphocyte proliferative response to one or more metals present in their own metal reconstructions. Results of this study thus indicated that dental alloys-by virtue of their corrosion process-might pose a significant risk to immunologically susceptible patients.

In vivo effects of dental casting alloys.

OBJECTIVE: Corrosion products of different metallic alloys used in prosthetic dentistry often cause the development of a bluish-grey pigmentation of gingiva and oral mucosa. The aim of this study was to determine the content of metals in metallic pigmentations and evaluate the immune response to metals found in the oral cavity. MATERIAL AND METHODS: The local tissue reactions were investigated clinically by electron microscopy and by energy dispersive x-ray microanalysis. An extensive anamnesis of the patients was recorded as well as earlier contacts with health care institutions. The immunological response to metallic components of dental alloys was evaluated in 34 patients by MELISA, a modified test for lymphocyte proliferation. In addition, cytokines in culture media were determined in 10 persons by the Human Inflammation Antibody Array. RESULTS: Dense particles containing metals were found in the matrix among collagen fibrils and in close proximity of the lamina basalis of the gingival epithelium. Particles were also localized intracellularly in fibroblasts, macrophages, and endothelial cells. Metallic depositions consisted predominantly of silver accompanied by selenium and sulphur. Twenty five out of 34 patients revealed high lymphocyte reactivity (positive MELISA test) to one or more metal components of dental restorations. A correlation between the positivity in MELISA test and number of dental alloys in the oral cavity was also found. Twenty MELISA positive patients suffered from serious health problems (various allergies, autoimmune diseases, Parkinson's syndrome etc.). Nickel and inorganic mercury were the most common sensitizers in vitro. The cytokine assay revealed that mercury chloride activated predominantly TH2 lymphocytes, while nickel chloride activated mainly TH1 lymphocytes. CONCLUSIONS: Metallic pigmentations in the oral cavity demonstrate a corrosion process and may pose a risk in immunologically susceptible patients.

Dental amalgam as one of the risk factors in autoimmune diseases.

BACKGROUND: Experimental and clinical data published recently show that dental amalgam can give rise to undesirable immunological responses in susceptible individuals. In genetically susceptible strains of experimental animals, mercury and silver can induce autoimmune responses. Sera of patients sensitive to mercury were found to have a higher incidence of autoantibodies relative to controls. OBJECTIVE: The aim of this study was to determine possible presence of antinuclear SSB/La autoantibodies after the in vitro stimulation of peripheral blood lymphocytes with HgCl2. METHODS: Lymphocytes were obtained from patients with autoimmune thyroiditis and increased response to mercury in vitro. Mononuclear cells were cultivated for 6 days with 100 microl HgCl2 solution or with pure medium and the levels of antinuclear autoantibodies SSB/La were assayed by a commercial SSB/La ELISA kit. RESULTS: Increased production of SSB/La autoantibodies in the media following stimulation of peripheral blood lymphocytes with HgCl2 was found in all cases. Using the Student's paired test, the results were significant on the p=0.05 significance level. CONCLUSION: Results imply that, in some patients with thyroiditis, mercury from dental amalgam can stimulate the production of antinuclear antibodies. Dental amalgam may be a risk factor in some patients with autoimmune disease.