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Introduction and objective: Cast post and cores are an important tool in the reconstruction of a dental crown. This article analyzes the state of cast metallic posts, made of alloys with high silver content, in cases where the restoration failed. Our aim is to point out the risks associated with the use of these alloys. Material and methods: A group of patients, based on a variety of dental indications, to whom it was necessary to extract either teeth with cast post and core or remove cast metallic posts or crowns. Overall, we analyzed 23 prosthetic works that have been exposed to the oral environment for 10 to 29 years, and discuss seven cases with a known history. The state of extracted samples was investigated by scanning electron microscopy and the elemental composition was determined by X-ray energy dispersive analysis (EDS / EDAX). Results and conclusion: The analysis showed that the corrosion problems of cast post and cores relate to the inner wire component as well as cast metallic post. In a situation when the corrosion environment penetrates to the core area, the corrosion process can lead to the formation of bulky iron corrosion products or ions of soluble silver compounds. This results in a strain, which may cause a longitudinal fracture of the tooth root and tissue pigmentation. Since alloys with high silver content are still part of the inventory of dental laboratories and the silver-tin alloy is still offered in the dental market, we felt it nece-ssary to highlight the risk aspects associated with manufacturing root extensions from these materials.

Introduction: Macrophages, the cells of the innate immunity play the significant role in immune reactions. In the early stages of inflammatory processes they are the main source of pro-inflammatory cytokines. Cytokines are produced during the interaction of cells with antigen and play an important role in the activation and regulation of immune response. Aim and Method: Our study aimed at exploring their production in a cell line THP1 (monocyte-macrophage cell line of human origin), cultivated for five days with an addition of salts of titanium, mercury, chromium, cobalt, nickel and palladium, which are frequent components of dental alloys. In the case of corrosion in the oral cavity environment these alloys can evoke in some patients a hypersensitive response. Results and Conclusion: The ions under study were found to affect the cells of the THP1 line to different extents, giving rise to a lowered but also enhanced production of chemotactic factors, pro-inflammatory cytokines and also cytokines participating in the regulation of the immune response. The influence of their production after exposition to metals can then lead to the development of an undesirable response to dental alloys.

In some patients, a blue-grey stained areas (pigmentation) developed after a certain period of time in the area of tooth crown. The paper infers the mechanism of pigmentation development, which is based on corrosion processes of materials used in the tooth reconstruction. In order to determine the conditions to which metal materials are exposed in vivo, oxidation-reduction potentials and pH of saliva and sulcular fluid were measured. The pH of saliva was in the range of 4.8 - 7.8 and that of sulcular fluid was 6.3 - 7.8. The oxidation-reduction potentials reached the values of 0.109-0.432 V/SHE in saliva and 0.149-0.344 in sulcular fluid. The analysis of extracted prosthetic-treated teeth demonstrated existence of crevice between the crown and tooth tissue, which enable the oral electrolyte to reach the post-core. A laboratory study demonstrated the possibility of releasing silver from amalgam and the Koldan alloy, materials used in practice in construction of post-cores, into model saliva samples in the form of soluble corrosion products. The rate of this process was in the range of 0.35-1.11 μg/cm2 per day. In the space between the crown and tooth, other corrosion mechanisms may take part which follow to the increase of corrosion agressiveness of the environment. Simulation of this influence demonstrated that the increased concentration of chloride and thiocyanate ions increases the corrosion rate of low-copper amalgam and the Koldan alloy, the change of corrosion behavior in the higher-copper amalgam proved to be unsubstantial. The study demonstrated that the release of soluble corrosion products of silver in the oral cavity environment may occur. Their transport into the adjacent soft tissues and deposition in the form of insoluble substances may result in the development of pigmentations.

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.

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.

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.