Cell-mediated immunity in juvenile periodontitis and levamisole treatment.

Immunostimulation with levamisole was attempted in eight patients with juvenile periodontitis and six reference patients with gingivitis but without loss of periodontal attachment. The following parameters were studied before and after levamisole treatment: gingival status, the concentration of serum immunoglobulins and complement, T and B lymphocyte ratio, leukocyte migration inhibition and lymphocyte transformation responses by dental plaque bacteria, PPD or PHA, and lymphocyte ATP-ase activity. In juvenile periodontitis cell-mediated immunity to dental plaque antigens seemed to be impaired, but the response was not restored by treatment with levamisole. There was no evidence of a broader suppression of cell-mediated immunity in juvenile periodontitis and there was no significant clinical effect of levamisole treatment. It is suggested that the apparent suppression of in vitro cell-mediated immunity to dental plaque bacteria in juvenile periodontitis is a secondary change, caused by a long-standing chronic infection.     

Cell-mediated immunity in juvenile periodontitis and levamisole treatment

abstract — Immunostimulation with levamisole was attempted in eight patients with juvenile periodontitis and six reference patients with gingivitis but without loss of periodontal attachment. The following parameters were studied before and after levamisole treatment: gingival status, the concentration of serum immunoglobulins and complement, T and B lymphocyte ratio, leukocyte migration inhibition and lymphocyte transformation responses by dental plaque bacteria, PPD or PHA, and lymphocyte ATP-ase activity. In juvenile periodontitis cell-mediated immunity to dental plaque antigens seemed to be impaired, but the response was not restored by treatment with levamisole. There was no evidence of a broader suppression of cell-mediated immunity in juvenile periodontitis and there was no significant clinical effect of levamisole treatment. It is suggested that the apparent suppression of in vitro cell-mediated immunity to dental plaque bacteria in juvenile periodontitis is a secondary change, caused by a long-standing chronic infection.     

Pigmented lesions of the oral mucosa and perioral tissues: a flow-chart for the diagnosis and some recommendations for the management

The term "pigmentation of the oral mucosa" is applied to a wide range of lesions or conditions featuring a change of color of oral tissues. Lesions not associated with an accumulation of pigment (e.g., Fordyce spots) are usually not classified as pigmented lesions. Two groups of pigmented lesions of the oral mucosa are recognized: 1) melanin-associated lesions, including racial pigmentations, melanotic macules, melanocytic nevi, and malignant melanoma; and 2) nonmelanin-associated lesions (e.g., blood-related pigmentations, metallic pigmentations). This paper presents a clinicopathologic review of the recent literature with emphasis on the main diagnostic features, including the use of immunohistochemical markers. A flow-chart is added that may help the clinician in the diagnosis and management of these lesions.     

Solubilized dental plaque is mitogenic for nylon wool-purified human cord blood T lymphocytes

Human cord blood T lymphocytes were purified by filtration through nylon wool columns and tested for their ability to synthesize DNA in response to stimulation with solubilized dental plaque, phytohemagglutinin and streptolysin O. Ninety out of 106 cord blood T lymphocyte preparations (85%) responded significantly (p≤0.05) to solubilized dental plaque. DNA synthesis was maximal after 7 days of culture; 20 μg of solubilized dental plaque was the optimal dose. A similar frequency of significant responses (89%) was obtained with the T lymphocyte mitogen, phytohemagglutinin; however, streptolysin O, an antigen, stimulated only 23% of the T lympyhocyte preparations significantly. The high frequency of significant cord blood T lymphocyte responses to solubilized dental plaque was not affected by maternal periodontal status, nor could any evidence be found for the removal of adherent suppressor cells by the nylon wool purification. Furthermore, cord blood leukocyte and mononuclear cell cultures responded about as frequently as, and synthesized more total DNA than T lymphocyte cultures to solubilized dental plaque. Freshly prepared solubilized dental plaque was shown to contain inhibitors as well as activators of lymphocyte transformation, and was significantly less immunogenic (mitogenic) than an older, frozen preparation of solubilized dental plaque. These results indicate that solubilized dental plaque contains one or more mitogens for human T lymphocytes.     

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.     

Outcome of treatment of patients with orofacial discomfort complaints

In 113 patients with a wide variation of orofacial and general complaints, which they assumed were caused by galvanic currents and/or metallic restorations, the initial and long-term development (3 years) after treatment was studied. Many treatment procedures were tried; besides information and follow-ups, each patient underwent in average of 6.6 different measures. The often time-consuming treatment was individualized, based on each patient's signs and symptoms. Besides conventional dental treatment, stomatognathic therapy and medical treatment which were frequently needed, metallic constructions were removed in 54% of the patients. The initial outcome of treatment was evaluated as successful both by patients and therapists in about 80%, but half of the patients reported recurrences, more often after removal of metallic constructions than after other dental treatment, while the dentists found recurring clinical signs in only 13% of the patients and without correlation to type of treatment. It is concluded that these patients need a careful oral examination and dental treatment of observed local pathology and defects of dental constructions, but removal of metallic constructions should be avoided when not indicated. Many of these patients will also need medical consultation and treatment, and a collaboration between the dentist and the physician is then recommended.     

Hypersensitivity to mercury, nickel and chromium in relation to dental materials

Three metals which are used in dental materials are recognized as causing sensitization sufficiently frequently to consider whether problems might arise from their use in dentistry. These metals are, mercury, nickel and chromium. Nickel is by far the commonest sensitizer, 10 per cent of women are allergic to nickel; sensitization usually occurs through jewellery or fasteners on articles of clothing. Chromium (as chromate) is a much less common sensitizer for several reasons. Sensitization only occurs through hexavalent salts of chromate and the degree of exposure of humans to these salts is much less than to either nickel or mercury. The true incidence of mercury sensitization is difficult to ascertain because many of the materials which were used for patch testing previously and on which statistics were based, contained unnecessarily high concentrations of mercury, and the pattern of mercury allergy is changing because many substances which contain mercury and were used frequently are not now employed. Although metallic mercury can sensitize the evidence would suggest that if dental amalgams ever cause people to become allergic to mercury, it is an extremely rare occurrence. Problems with mercury-containing amalgams in those sensitized are also rare, only 28 cases have been recorded in the literature. Thus, it is likely that at the present time sensitization to mercury is uncommon and decreasing. There is even less evidence that nickel or chromate in dental materials actively sensitize and it is exceptionally rare to have problems with these metals in a prosthesis in someone who is already sensitized.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical findings in patients with orofacial discomfort complaints

In 113 patients with orofacial and general complaints, which they assumed were caused by galvanic currents and/or metallic restorations, clinical dental and medical examinations were performed. Most of the patients had natural teeth with dental metallic restorations. A number of dental diagnoses, such as caries, pulpitis, periapical osteitis and periodontitis, were found. However, 16% were edentulous in one or both jaws and had complete dentures. 69% had possible metal contacts. Some oral mucosal changes were observed, but they were as frequent in patients without as in those with metal contact possibility. Signs of parafunctions and functional disturbances of the masticatory system were extremely frequent. A careful oral examination in these patients thus revealed many clinical dental and oral signs that could be more-or-less related to the complaints. Because of the extremely varying symptoms reported, however, only a small proportion could be fully explained by odontological and/or medical diagnoses, and in 38% of the patients, no clear odontological diagnosis was found that could explain the complaints.     

Evaluation of biocompatibility of metallic dental materials in cell culture model

Biocompatibility of metals for dental use was tested using a three-dimensional model consisting of oral keratinocytes cultured on de-epidermised sub-mucosa. The toxicity of orthodontic metallic wire and soldering material was assessed through parameters such as the morphology and growth rate of the keratinocytes, as well as by classical histology, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The sharp composition of metallic wires and soldering materials was assessed by Auger Electron Spectroscopy (AES). The results of our experiment showed that the new model revealed inhibition of keratinocyte growth and stratification near soldering material, whereas mucosal cells were able to grow and layer out on dental wire. It is concluded that this experimental model, which simulates the oral environment, is useful for studying the effects of materials for dental use for its sensibility and reproducibility. Moreover it can provide morpho-functional information which cannot be achieved by traditional methods.     

A method of eliminating streak artifacts from metallic dental restorations in CTs of head and neck cancer patients

The purpose of this report was to develop a method to reduce streak artifacts derived from dental restorations in CT-imaging of the head and neck region. We selected six patients who were being treated for head and neck cancer and who had metal-derived artifacts on their CT that limited pre- or post-surgical visualization. The metal restorations were removed and replaced with non-metallic composite resin restorations. The CT was repeated as required on completion of the procedures. The streak artifacts were completely eliminated in patients in whom radiolucent composite materials were used. Patients have been followed for 6–26 months with no complications or breakdown of the restorations. The substitution of radiolucent for metallic restorations in special cases should be considered as a solution to CT dental artifact problems.     

Effect of placement of amalgam restorations on urinary mercury concentration

Dental amalgam emits mercury, especially during setting. In addition, the preparation of the amalgam and its compaction into the cavity involve unbound metallic mercury or create a waste product with free metallic mercury. The present study was performed to explore whether emission of mercury in these situations would measurably influence the individual urinary mercury concentration of dental patients as a result of a single-session treatment with dental amalgam restorations. Informed consent was obtained from the patients of nine children about to be treated with amalgam restorations as part of their regular dental care. The children delivered a total of five morning urine samples before, during, and after the treatment period. No effect on the urine mercury concentration was found during the treatment period. Conclusively, one single session of amalgam treatment did not per se represent a mercury exposure of sufficient quantity to be detectable in a longitudinal, individual study.     

The ultrastructural localization of the corrosion products of dental amalgam

The ultrastructural localization of corrosion products released from dental amalgam implants in rat subcutaneous tissue was studied by means of a sulphide-silver technique. Implants stimulated a prolonged inflammatory response with delayed granulation tissue formation and slow and faulty collagen formation. The metallic corrosion products were found both in cells and in association with matrix components. Intracellular metal deposits were predominantly in the cytoplasmic matrix and in vacuoles in the early (19 day) lesions, but at 60 days there was metal in many nuclei, both viable and dead. Collagen fibrils had metal on the surface and vascular basement membranes had granules of bound metals.     

口腔内金属修复物与磁共振伪影的关系

金属与合金作为口腔修复材料,在口腔,临床中应用非常广泛。但在进行口腔颌面部和脑部磁共振检查时,口内某些金属修复物可使图像上出现伪影,干扰正常解剖结构和病变组织的显示。本文就口腔金属修复物与磁共振伪影相互关系的研究进展作一综述。     

Macrophages related to dental implant failure

PURPOSE: The aim of this study was to evaluate, histologically and quantitatively, the presence of macrophages loaded with metallic particles in the periimplant soft tissues of failed titanium (Ti) dental implants. MATERIALS AND METHODS: The study was performed on sections of metallic Ti implants embedded in methyl methacrylate resin that exhibited macrophages in the soft tissues contiguous with the implant. The volume of periimplant soft tissue was evaluated, and the number of macrophages was determined. The particles within macrophages were analyzed by energy-dispersive x-ray analysis. RESULTS: Macrophages were more abundant in the zone adjacent to the metallic implant as compared with the zone further away from the implant. Energy-dispersive x-ray analysis revealed the presence of Ti within macrophages. CONCLUSIONS: Macrophages loaded with Ti particles can be associated with a corrosion process. The method proposed would allow for the objective evaluation of the presence of macrophages associated with dental implants and other orthopedic materials that contain Ti or other metals.     

The national survey of adverse reactions to dental materials in the UK: a preliminary study by the UK Adverse Reactions Reporting Project

OBJECTIVE: Dental treatment involves the use of a wide range of materials. Many of the dental materials or their components pose a potential risk to the patient and member of the dental team. Pre-market biocompatibility testing cannot guarantee absolute safety, making monitoring of materials likely to cause an adverse reaction essential. The prevalence of adverse reactions to dental materials amongst dental patients and staff has not been systematically monitored in the UK. This project aims to develop a systematic approach to the evaluation and monitoring of the extent and severity of adverse reactions to dental materials in the UK. METHOD: Through the distribution of reporting forms to dental surgeries and laboratories in the UK, the ARRP has received 1,075 complete reports relating to adverse reactions seen or experienced by dental staff and patients. RESULTS: The main findings were that different materials cause adverse reactions to different groups of people. The largest proportion of patient related adverse reactions were reported to be due to metals (n = 175). These were mainly amalgam associated oral lichenoid reactions (n = 124). Dental technicians reported acrylic resin as the causal factor of hand dermatitis in 61% (44 out of a total 72) of cases reported. Finally, dental surgery staff reported gloves as causing hand dermatitis in 75% of cases (398 out of a total 531). CONCLUSIONS: Different dental materials affect different person groups depending on their exposure to the material. Dental staff are most at risk from an adverse reaction to latex gloves, whereas most reported reactions for patients were due to metals. For dental technicians the biggest danger of an adverse reaction was from acrylic resins. There is a need to continue to raise the awareness among dental professionals of the existence of the Adverse Reactions Reporting Project so as to overcome problems of under-reporting.     

Drug-induced palatal pigmentation

A bstract — Palatal pigmentations are rare in children. Four cases of palatal pigmentation associated with the prescribed use of the drug amodiaquine are tabulated and two are reported in detail. The wider clinical application of this anti-malarial drug and the potential for drug-induced palatal pigmentations are of dental interest. The pigmentation persists for an indefinite period after withdrawal of the drug.     

Immunological studies on the peripheral blood mononuclear cells in metal allergy patients

Recently, the number of patients with dental metal allergy has risen significantly. The aim of this study was to evaluate the clinical availability of the lymphocyte stimulation test (LST) using metal reagents as a method for diagnosing metal allergy. In vitro, peripheral blood mononuclear cells (PBMC) from 18 patients with metal allergy and five healthy volunteers were examined by LST using 12 metal reagents (HAuCl4, PdCl2, NiSO4, CoCl2, CuSO4, SnCl4, K2Cr2O7, MoCl5, H2PtCl6, IrCl4, AgBr, FeCl3). To define metal allergy, a patch test (PT) was performed with metal reagents, and then the components of dental alloys in their mouth were analyzed. The expressions of CD 4, CD 8, CD 25, and CLA of metal-specific T cells were determined by flow cytometric analysis (FACS). PBMC from patients with positive PT showed LST positive for nickel sulfate (Ni), gold chloride (Au), palladium chloride (Pd) and cobalt chloride (Co). The results of LST in other metals indicated negative in spite of the positive result by PT. FACS results indicated the increase of CD 4 + T/CD 8 + alpha 4 + T cells, CD 4 + T/CD 8 + CLA+ T cells by stimulation with metal reagent. Thus, metal-specific T cells were stimulated in PT positive patients, so LST could be a more specific test for diagnosing dental metal allergy.     

Is Titanium Sensitivity Associated with Allergic Reactions in Patients with Dental Implants? A Systematic Review

Background: A worrying correlation which seems to be overlooked by clinicians is allergic reactions to titanium (Ti) in patients with dental implants. Purpose: The aim of the present review study was to assess whether or not Ti sensitivity is associated with allergic reactions in patients with dental implants. Materials and Methods: To address the focused question “Can Ti cause allergic reactions in patients with dental implants?”, databases were explored from 1977 until May 2010 using a combination of the following keywords: “allergy,”“dental,”“hypersensitivity,”“implant,”“oral,” and “Titanium.” Letters to the editor and unpublished data were excluded. Results: Seven studies (six clinical and one experimental) were included. The participants were aged between 14.3 and 84.1 years. In five clinical studies, Ti implants were inserted in the mandible. Five studies reported dermal inflammatory conditions and gingival hyperplasia as allergic reactions in patients with Ti dental implants. A case report presented swelling in submental and labial sulcus and hyperemia of soft tissues in a patient with Ti dental implants. Two studies reported that Ti implants are well tolerated in host tissues. The patch test was performed in two clinical studies for the diagnosis of allergic reactions. Memory lymphocyte immunostimulation assay and lymphocyte transformation tests were also performed. Conclusion: The significance of Ti as a cause of allergic reactions in patients with dental implants remains unproven.     

In vitro lymphoproliferative assays with HgCl2 cannot identify patients with systemic symptoms attributed to dental amalgam.

Dental amalgam is suspected, by some exposed individuals, to cause various systemic psychological, sensory, and neurological symptoms. Since not all amalgam-bearers experience such reactions, an individual characteristic--for example, a susceptible immune system--might explain these conditions. In vitro lymphocyte proliferation is a valuable tool in the diagnosis of allergy. With HgCl2 as the antigen, however, the test is hampered, because Hg2+ can cause unspecific lymphocyte proliferation, optimal at 1.4 to 9.5 micrograms HgCl2/mL. Recently, the use of suboptimal HgCl2 concentrations (< or = 0.5 microgram/mL) has been suggested to circumvent these problems. The main aim of this study was to investigate whether patients with systemic symptoms alleged to result from the presence of dental amalgam differ from healthy controls, with reference to in vitro lymphoproliferative responses to HgCl2 < or = 0.5 microgram/mL. Three different test protocols--lymphocyte transformation test (LTT) in micro- and macro-cultures, and the memory lymphocyte immunostimulation assay (MELISA)--were used. Other immune parameters--such as a standard patch test for dental materials, the number of T- and B-lymphocytes, monocytes, granulocytes, and NK cells in peripheral blood, allergic symptoms, and predisposition--were also investigated. Twenty-three amalgam patients, 30 healthy blood donors with amalgam, ten healthy subjects without amalgam, and nine patients with oral lichen planus (OLP) adjacent to dental amalgam and a positive patch test to Hg0 were tested. None of the investigated immune parameters revealed any significant differences between amalgam patients and controls. The sensitivity of in vitro lymphocyte proliferation ranged from 33 to 67%, with the OLP patients as a positive control group, and the specificity from 0 to 70% for healthy controls with a negative patch test to Hg0. Thus, despite the use of HgCl2 < or = 0.5 microgram/mL, a high frequency of positive results was obtained among healthy subjects with or without dental amalgam. Consequently, in vitro lymphocyte proliferation with HgCl2 cannot be used as an objective marker for mercury allergy in dental amalgam-bearers.     

The stimulation of human peripheral blood lymphocytes by solubilized dental plaque: macrophage and T-cell dependence

This study compared the ability of human peripheral blood lymphocyte subpopulations from individuals with moderate periodontitis to proliferate in response to stimulation with solubilized dental plaque, phytohemagglutinin (PHA), pokeweed mitogen (PWM) and purified protein derivative (PPD). Unseparated mononuclear lymphocytes and recombined purified T and B lymphocytes (4/1) responded significantly to all of the stimulants. DNA synthesis in response to solubilized dental plaque was maximal after 6 to 7 days of culture; the optimum dose was usually 10 to 20 micrograms/ml. T lymphocyte subpopulations purified by rosetting with sheep red blood cells and density gradient centrifugation responded well to PHA and PWM, but were unresponsive to solubilized dental plaque and PPD unless supplemented with 2% autologous macrophages, demonstrating that T cell responses to solubilized dental plaque and to PPD are macrophage-dependent. T cell-depleted enriched B lymphocyte subpopulations were poorly responsive to all of the tested stimulants; however, the responses of these cells to solubilized dental plaque and to the known T cell-dependent B cell mitogens PWM and PPD were increased significantly by the presence of 10% mitomycin C-treated T cells, demonstrating that B cell proliferation to solubilized dental plaque is T cell-dependent. Thus, cellular interactions between macrophages, T lymphocytes and B lymphocytes are required to obtain optimal proliferative lymphocyte responses to solubilized dental plaque. Since both T and B lymphocytes respond to dental plaque stimulants, they both have the potential to mediate periodontal inflammation and tissue destruction whenever dental plaque stimulants gain entrance into the periodontal tissues.