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.

Sensitization to inorganic mercury could be a risk factor for infertility.

INTRODUCTION: Heavy metals can negatively influence the reproduction due to the fact that they are able to impair the immune reactions including autoantibody production in susceptible individuals. In such a way the infertility could be also caused by altered pathologic immune reaction. AIM OF THE STUDY: To investigate the in vitro lymphocyte reaction after stimulation with metals and production of gamma interferon and antisperm antibodies in supernatants after lymphocyte stimulation in patients with infertility and with proven antisperm antibodies in their serum. The cause of antisperm antibodies presence was not determined. METHODS: The diagnosis of metal allergy was performed by the lymphocyte proliferation method modified for metals (MELISA) in supernatants of tissue cultures of lymphocytes without the antigen stimulation and after stimulation with mercury chloride, the in vitro production of gamma interferon and antisperm antibodies was studied by ELISA. RESULTS: More than 50% of patients were reacting to mercury, iron, aluminium and silver as mean by lymphocyte reactivity. When compared the lymphocyte reaction in patients with and without mercury allergy we found that the lymphocytes of patients with mercury intolerance produced less gamma interferon and more antisperm antibodies in supernatants after mercury stimulation of their lymphocytes. CONCLUSION: In patients with metal intolerance diagnosed by the MELISA test the release of metal ions from dental materials can be one of the stimulating factors which may adversely affect fertility.

Effect of intravenous immunoglobulins on in vitro immunoglobulin formation in patients with antibody immunodeficiency.

Seventeen patients with antibody immunodeficiency (9 subclass IgG immunodeficiencies, 8 common variable immunodeficiencies) and clinically unambiguous immunodeficiency symptomatology participated in the study with 14 healthy donors. The patients were given regular intravenous immunoglobulin (IVIG) infusions with Endobulin. Blood was collected before and 7 days after infusion of the usual IVIG dose. Mononuclear cells were isolated from peripheral blood (PBMC) of the patients by Ficoll-Paque gradient centrifugation. In order to monitor the ability to inhibit or activate polyclonal production of immunoglobulins in vitro, we stimulated PBMC with pokeweed mitogen (PWM) and with a mixture of pokeweed mitogen + concanavalin A (PWM+ConA). We found that an immunomodulatory effect of IVIG persists in vitro even one week after infusion. Polyclonally stimulated IgA and IgM production was suppressed by IVIG infusion mainly in patients with IgG subclass deficiency. The positive stimulatory effect of IVIG infusion on IgG production was confirmed. The IgG production increased in vitro after infusion in both groups of patients and was significantly higher than in healthy donors. Co-stimulation of PWM-stimulated cells with ConA caused an inhibition of immunoglobulin release in normal healthy donors. The infusion supported the capability of ConA to inhibit IgG production in vitro in patients with IgG subclass deficiency, whereas an increase in IgG production with PWM+ConA stimulation after infusion was found in CVID patients. We assume that lymphocytes activated by ConA produce suppressive factors, which can be affected by the IVIG infusion and which can have both an immunostimulatory and an immunosuppressive effect.

The integrity of bonded amalgam restorations: a clinical evaluation after five years.

BACKGROUND: Bonded amalgam restorations have been studied extensively in vitro, but few long term clinical studies exist. The authors examined the clinical performance of bonded amalgam restorations after five years of clinical service an compared it with that of nonbonded amalgam restorations. METHODS: The authors placed 75 bonded and 62 nonbonded amalgam restorations in patients needing restorations. Most of the restorations were placed in conventional preparations; six bonded restorations were placed in nonretentive cavities. They were evaluated after a five-year period of clinical service by two trained dentists using a mirror and explorer and following modified U.S. Public Health Service criteria. RESULTS: Statistical analysis (via Fisher exact test) showed no significant differences between the two techniques when conventional preparations were used. Restorations in nonretentive preparations were successful during this period. CONCLUSIONS: Bonded and nonbonded amalgam restorations yielded similar results in conventional preparations after five years of clinical service. Bonded amalgam restorations were clinically successful in a limited number of nonretentive preparations over a five-year period. CLINICAL IMPLICATIONS: Bonded amalgam restorations can be used successfully in conventional preparations and possibly in nonretentive preparations as well, and can be expected to last at least five years.