The role of patch testing in the management of oral lichenoid reactions.

BACKGROUND AND OBJECTIVES: The distinction of oral lichenoid reactions from oral lichen planus may be difficult in a clinical setting. Our aims were to ascertain the utility of patch testing to confirm the association of oral lichenoid reactions with dental restorations and to identify the benefits of replacement of restorations, primarily made of amalgam. METHODS: Patients seen in an oral medicine unit over a 10-year period diagnosed with oral lichenoid reactions, with oral lichen planus resistant to treatment or with atypical lichenoid features were included in this study. All had been subjected to skin patch testing. Histopathology reports blinded to patch test results were scrutinized. Patch-test-positive subjects were advised to have their restorations replaced. All were followed up to determine disease resolution for at least 3 months thereafter. RESULTS: Among 115 patients, 67.8% patients reacted positive to a dental material and nearly a quarter to mercury or amalgam. No correlation was found between pathology and skin patch testing results (P = 0.44). A total of 87 patients were followed up in clinic, and among 26 patch-test-positive patients who had their amalgam fillings replaced, moderate to complete resolution was noted in 81%. CONCLUSIONS: Skin patch testing is a valuable tool to confirm clinically suspected oral lichenoid reactions. Pathology diagnoses of oral lichenoid reactions did not correlate with patch test results. Prospective studies are needed to ascertain that a clinically suspected oral lichenoid reaction with a positive patch test result may resolve after the replacement of amalgam fillings.

Secondary Caries Development in in situ Gaps next to Composite and Amalgam.

This in situ study investigated the secondary caries development in dentin in gaps next to composite and amalgam. For 21 days, 14 volunteers wore a modified occlusal splint containing human dentin samples with an average gap of 215 µm (SD=55 µm) restored with three different materials: Filtek Supreme composite, Clearfil AP-X composite and Tytin amalgam. Eight times a day, the splint with samples was dipped in a 20% sucrose solution for 10 min. Before and after caries development, specimens were imaged with transversal wavelength independent microradiography, and lesion depth (LD) and mineral loss (ML) were calculated. The LD and ML of the three restoration materials were compared within patients using paired t tests (α=5%). In total 38 composite samples (Filtek n=19 and AP-X n=19) and 19 amalgam samples could be used for data analysis. AP-X composite presented the highest mean values of LD and ML of the three restorative materials. Amalgam showed statistically significantly less ML (Δ=452 µm×vol%) than the combined composite materials (p=0.036). When comparing amalgam to the separate composite materials, only AP-X composite showed higher ML (Δ=515 µm×vol%) than amalgam (p=0.034). Analysis of LD showed the same trends, but these were not statistically significant. In conclusion, amalgam showed reduced secondary caries progression in dentin in gaps compared to composite materials tested in this in situ model.

Sensitization to palladium and nickel in Europe and the relationship with oral disease and dental alloys.

BACKGROUND: The role of palladium and nickel sensitization in oral disease and dermatitis is not fully understood. OBJECTIVES: To investigate whether sensitization to these metals was associated with exposure to dental alloys and oral and skin complaints/symptoms in a European multicentre study. METHODS: In six dermatology clinics, patch tests with palladium (3% Na2 PdCl4 ; Pd = 102.0 µmol/g) and nickel (5% NiSO4 .6H2 O; Ni = 190.2 µmol/g) were performed in consecutive patients, and patients' characteristics were collected with a questionnaire and a clinical investigation. RESULTS: In total, 906 patients were included, of whom 24.3% reacted to palladium and 25.2% to nickel. The rate of monosensitization was 6-7% for both metals. Palladium sensitization (as opposed to no sensitization to both metals) was associated with exposure to dental crowns [odds ratio (OR) 2.0], skin reactivity to metals (OR 2.8), oral lichenoid lesions (OR 4.7), xerostomia (OR 7.3), and metal taste (OR 20.7), but not with eczema, stomatitis, or oral burning sensation. Additionally, xerostomia (OR 8.7) and metal taste (OR 4.6) were associated with sensitization to both metals. CONCLUSIONS: Clinically, it is important for palladium-sensitized patients to undergo an oral examination, with particular attention to the presence of/exposure to dental crowns. In the case of metal contact allergy, exposure to dental crowns could play a role.

Palladium-based dental alloys are associated with oral disease and palladium-induced immune responses.

BACKGROUND: Palladium (Pd) and gold (Au) based dental alloys have been associated with oral disease. OBJECTIVES: This study was designed to explore possible associations between the presence of Au-based and Pd-based dental alloys, and oral lesions, systemic complaints, and specific in vivo and in vitro immune responses. METHODS: The investigated population consisted of three groups: 26 non-metal-allergic volunteers, 25 metal-allergic patients, and 20 oral disease patients. Medical histories were taken, oral examinations were carried out, and compositions of all dental alloys were determined. Then, Au and Pd patch tests and in vitro assays were performed, revealing cytokine production by peripheral blood mononuclear cells [T helper (Th)1, interferon-γ; Th2, interleukin (IL)-5 and IL-13] and lymphocyte proliferation (LTT-MELISA(®) ). RESULTS: Non-plaque-related gingivitis was associated with the presence of Pd-based dental alloys, and Pd-positive patch tests and in vitro assays. Collectively, participants with Pd-based dental alloys showed increased Pd patch test reactivity (p < 0.05) and lymphoproliferation (p < 0.05). In contrast, oral lichenoid lesions were associated with Au-based alloys (p < 0.05), but this was not reflected by Au-specific immunoreactivity. CONCLUSIONS: Oral lesions and Pd-induced immune responses are associated with the presence of dental alloys. However, most oral disease patients did not show positive patch test results or in vitro signs of specific immunoreactivity, suggesting local toxic reactions or the involvement of innate immune responses.

Systemic allergic contact dermatitis associated with allergy to intraoral metals.

Contact (allergic) dermatitis is a skin disorder related to natural exposure to various allergens. Systemic contact dermatitis (SCD) describes a cutaneous eruption in response to systemic exposure to an allergen. The exact pathologic mechanism remains uncertain. Herein we describe a 36-year-old woman with symmetric systemic allergic contact dermatitis, unresponsive to conventional treatment, associated with dental alloy-contact hypersensitivity. We did skin patch testing and the blood lymphocyte transformation test (LTT) from the dental allergen series to assess contact allergy to restorative dental materials. On patch testing, positive allergic contact dermatitis reactions to metals occurred (nickel, potassium dichromate, and gold). Nickel hypersensitivity was confirmed by LTT, which also revealed silver-amalgam sensitization. Our case report highlights the need to consider adverse reactions to base-metal dental alloys in the differential diagnosis of cases of systemic allergic contact dermatitis.

A clinical report of an oral lichen planus associated to epidermoid carcinoma in contact with metallic restorations.

The aim of this study was to relate the clinical case of a patient with oral lichen planus (OLP) and a history of epidermoid carcinoma associated with metallic restorations. The etiology of OLP is a mucocutaneous disease, which is poorly understood. Studies point to the potential of malignant transformation of OLP and its association with metallic restorations. The metallic restorations were replaced by crowns with a ceramic covering associated and osseointegrated implants in the edentulous areas. About 1 year later, it was observed a bilateral regression of the tongue lesions. The replacement of metallic restorations can contribute to improvement of OLP.

Practice-based clinical evaluation of metal-ceramic and zirconia molar crowns: 3-year results.

This practice-based study evaluates the clinical performance of conventionally luted metal-ceramic and zirconia molar crowns fabricated with pronounced anatomical core design and a prolonged cooling period of the veneering porcelain. Fifty-three patients were treated from 07/2008 until 07/2009 with either metal-ceramic crowns (MCC) (high-noble alloy + low-fusing porcelain) or zirconia crowns (Cercon System, DeguDent, Germany). Forty-nine patients (30 women/19 men) with 100 restorations (metal-ceramic: 48/zirconia: 52, mean observational period: 36·5 ± 6 months) participated in a clinical follow-up examination and were included in the study. Time-dependent survival (in situ criteria), success (event-free restorations) and chipping rates (defects of the veneering ceramics) were calculated according to the Kaplan-Meier method and analysed in relation to the crown fabrication technique, using a Cox regression model (P < 0·05). Three complete failures (metal-ceramic: 1, zirconia: 2) were recorded (survival rate after 3 years: metal-ceramic: 97·6%, zirconia: 95·2%). Of the metal-ceramic restorations, 90·9% remained event-free (two ceramic fractures, one endodontic treatment), whereas the success rate for the zirconia was 86·8% (two ceramic fractures, one endodontic treatment, one secondary caries). No significant differences in survival (P = 0·53), success (P = 0·49) and ceramic fracture rates (P = 0·57) were detected. The combination of a pronounced anatomical core design and a modified firing of the veneering porcelain for the fabrication of zirconia molar crowns resulted in a 3-year survival, success and chipping rate comparable to MCC.

Titanium hypersensitivity. A hidden threat for dental implant patients?

Titanium and its alloys have been widely used for dental prosthetic devices because of their superior mechanical properties and biocompatibility. However, the incidence of titanium hypersensitivity or allergy is still unknown and the discussion about its existence is ongoing. Unexplained implant failures have also forced dental clinicians to investigate the possibility of titanium hypersensitivity or allergy. This review focuses on the potential of dental implant-related titanium hypersensitivity or allergic reactions. It includes an examination of the existing scientific literature and current knowledge. Evidence-based data and studies related to titanium hypersensitivity in dental implant patients are also discussed.

[New type titan alloy with shape memory for use in dental implantology].

The paper summarizes the results of in vitro and in vivo studies that have proved biocompatibility and medical safety of Ta and Ti-Nb-Ta-bases alloys. According to some in vitro data Ti-Nb-Ta-based alloy possesses certain advantages when comparing to Ta-based. In particular, it contributes to elevation of viability of cellular elements and to definite increase of their adhesive potential.

Allergic contact stomatitis caused by a titanium nitride-coated implant abutment: a clinical report.

A patient developed contact mucositis after being treated with a titanium nitride implant abutment. Patch testing disclosed a positive reaction to titanium nitride. After removal of the titanium nitride-coated abutment and placement of an uncoated abutment, all signs and symptoms disappeared. This clinical report suggests that titanium nitride-coated abutments may be a potential allergen in some patients.

A delayed hypersensitivity reaction to a stainless steel crown: a case report.

Stainless steel crowns are commonly used to restore primary or permanent teeth in pediatric restorative dentistry. Here, we describe a case of a delayed hypersensitivity reaction, which manifested itself as perioral skin eruptions, after restoring the decayed first permanent molar tooth of a 13-year-old Caucasian girl with a preformed stainless steel crown. The eruptions completely healed within one week after removal of the stainless steel crown. The decayed tooth was then restored with a bis-acryl crown and bridge. Since no perioral skin eruptions occurred during the six-month follow-up, we presume that the cause of the perioral skin eruptions was a delayed hypersensitivity reaction, which was triggered by the nickel in the stainless steel crown.

Titanium allergy: could it affect dental implant integration?

PURPOSE: Degradation products of metallic biomaterials including titanium may result in metal hypersensitivity reaction. Hypersensitivity to biomaterials is often described in terms of vague pain, skin rashes, fatigue and malaise and in some cases implant loss. Recently, titanium hypersensitivity has been suggested as one of the factors responsible for implant failure. Although titanium hypersensitivity is a growing concern, epidemiological data on incidence of titanium-related allergic reactions are still lacking. MATERIALS AND METHODS: A computer search of electronic databases primarily MEDLINE and PUBMED was performed with the following key words: 'titanium hypersensitivity', 'titanium allergy', 'titanium release' without any language restriction. Manual searches of the bibliographies of all the retrieved articles were also performed. In addition, a complementary hand search was also conducted to identify recent articles and case reports. RESULTS: Most of the literature comprised case reports and prospective in vivo/in vitro trials. One hundred and twenty-seven publications were selected for full text reading. The bulk of the literature originated from the orthopaedic discipline, reporting wear debris following knee/hip arthroplasties. The rest comprised osteosynthesis (plates/screws), oral implant/dental materials, dermatology/cardiac-pacemaker, pathology/cancer, biomaterials and general reports. CONCLUSION: This review of the literature indicates that titanium can induce hypersensitivity in susceptible patients and could play a critical role in implant failure. Furthermore, this review supports the need for long-term clinical and radiographic follow-up of all implant patients who are sensitive to metals. At present, we know little about titanium hypersensitivity, but it cannot be excluded as a reason for implant failure.

Nickel sensitization in orthodontically treated and non-treated female adolescents.

BACKGROUND: The importance of the nickel exposure from fixed orthodontic appliances is under continuous discussion. OBJECTIVES: Our aim was to investigate nickel allergy and the risk of nickel sensitization among female adolescents during orthodontic treatment with fixed appliances as compared with non-treated female adolescents. SUBJECTS AND METHODS: Female patients starting or with ongoing orthodontic treatment (n = 30) and young females without a history of orthodontic treatment (n = 140) were studied. Patch testing with 5% nickel sulfate was carried out twice on each participant with an approximately 1-year interval. The subjects completed a questionnaire before the first testing. RESULTS: None of the 7 orthodontic patients with a positive patch test reaction to nickel had any clinically visible intraoral allergic symptoms during their treatment. No significant difference was seen in the occurrence of positive nickel reactions in regard to orthodontic treatment, or between the first and second tests. In the treatment group, 2 patients changed from nickel-positive to nickel-negative during the observation period, and one patient showed an opposite change. The quantity and course of changes in the repeated nickel patch test reactions did not differ significantly between the subjects with and without orthodontic treatment experience. CONCLUSIONS: Nickel sensitization from orthodontic appliances is improbable, but nickel sensitization may develop also during orthodontic treatment.

The effect of dental restoration type and material on periodontal health.

PURPOSE: To investigate the relationship between the type and material of dental restorations and periodontal health in a sample of Jordanians. MATERIALS AND METHODS: Patients attending the Dental Teaching Clinics of Jordan University of Science and Technology with restored teeth were examined. For every patient, the plaque index, gingival index, probing depth and clinical attachment level were recorded on restored and non-restored tooth surfaces. The restoration types were Classes II, III and V, in addition to crowns and bridge abutments. The restorative materials included amalgam, tooth-coloured materials (resin composite and glass ionomer), non-precious alloys, porcelain and acrylic. RESULTS: Class III restorations were associated with the lowest plaque index (0.62), gingival index (1.13), probing depth (1.62 mm) and clinical attachment level (0.31 mm). Class II restorations had the highest plaque index (0.99) and probing depth values (2.27 mm). Crowns and bridge abutments had the highest gingival index (1.65 and 1.61, respectively), high probing depth (2.01 and 2.15 mm), but a low plaque index (0.69 and 0.66). Class V restorations demonstrated the highest attachment loss (0.92 mm). Resin composite and glass ionomer restorative materials demonstrated the lowest gingival index (1.21) and probing depth (1.75 mm), whereas porcelain demonstrated the lowest plaque index (0.51) and clinical attachment level (0.14 mm). Amalgam was associated with the highest plaque index (1.01) and probing depth (2.29 mm). Non-precious alloys and acrylic covered castings demonstrated the highest gingival index (1.73 and 1.72, respectively) and clinical attachment level (1.00 and 0.88 mm). CONCLUSIONS: Crowns, bridge abutments (especially acrylic and non-precious metals) and Class II amalgam restorations appear to be associated with periodontal breakdown.

Cellular responses to cobalt-chrome and CP titanium--an in vitro comparison of frameworks for implant-retained oral prostheses.

The responses of cell types in peri-implant tissues to cobalt-chrome and titanium were studied in vitro. Cylinders were made from both a cobalt-chrome alloy and commercially pure titanium (length 6 mm, diameter 7.9 mm). Plastic tubes were placed over the cylinders to create cell culture wells, in which human epithelial cells or mouse fibroblasts were cultivated. Cell viability was studied using the Alamar Blue method. The surface structure of two samples of each material was analyzed with optical interferometry. The morphology of cells grown on cylinders of each material was studied with scanning electronic microscopy. Epithelial cells and fibroblasts in the titanium group were more viable than those in the cobalt-chrome group (p = 0.001 and p = 0.000, respectively). The titanium surfaces had a greater height deviation (S(a), p = 0.027) but were less dense (S(ds), p = 0.044) than the cobalt-chrome group. The scanning electronic microscopy revealed no major deviations from normal cell morphology. Within the limitations of the present study, the findings indicate that epithelial cells as well as fibroblasts have a stronger negative response to cobalt-chrome alloy than to titanium. We suggest that these differences can be explained only bythe material per se and not by the minor differences in surface structure. Further and clinical studies are needed to confirm the significance of these findings.

Oral lichenoid reaction associated with tin component of amalgam restorations: a case report.

Amalgam or its components may cause type IV hypersensitivity reactions on the oral mucosa. Majority of the reported cases involved a delayed hypersensitivity to mercury. A case of bilateral oral lichenoid reaction is presented, which was present in relation to amalgam restorations. Histopathological features were compatible with lichenoid mucositis. Patch test was positive with pulverized amalgam and tin. The lesion healed up after replacement of restorations with an intermediate restorative material. The clinician should be aware of all possible pathological etiologies of white lesions. If there is any doubt about the nature or management of an unusual oral lesion, referral to appropriate specialists is mandatory.

New Zealand dental practitioners' experience of patient allergies to dental alloys used for prosthodontics.

UNLABELLED: The biocompatibility of metal alloys has generated much concern for practitioners and patients alike over recent years. OBJECTIVES: To investigate dentists' experience of patient allergies to metal alloys used in prosthodontic restorations. DESIGN: Cross-sectional survey of New Zealand practising general dentists. METHODS: A random sample of 700 was taken from the New Zealand dental register. The questionnaire asked dentists whether any of their patients have encountered any allergic reactions to metal alloys. It also sought information on what alloys were being prescribed for use in different types of prosthodontic restorations. RESULTS: A response rate of 71.4% was obtained (N = 476). Some 83 dentists (17.4%) reported having encountered suspected metal allergies in patients; of those, 70 had had the allergies confirmed with a biopsy. Of the entire sample, 327 dentists (72.2%) were aware of the metals used in their restorations, and 201 (44.8%) specified the alloys used in their restorations. For cast removable prosthodontic restorations (such as removable partial dentures), base metal alloys were the most preferred choice; for full cast crowns, high noble alloys were the most favoured; noble alloys were the most favoured for both porcelain-fused-to-metal crowns and fixed-bridge restorations. CONCLUSION: As many as one in six general practising dentists have encountered allergic reactions to metal alloys in their patients. General practising dentists' awareness of the indications for the various metal alloys used in prosthodontic restorations should be raised, and biocompatibility issues should be clarified, so that dentists prescribe the optimum metal alloy for each type of restoration.

Allergy to nickel in orthodontic patients: clinical and histopathologic evaluation.

Adverse reactions stemming from the use of fixed and removable orthodontic appliances have been a cause for concern for both orthodontists and researchers in the health care field. Nickel often has been indicated as a biological sensitizer capable of causing short- and long-term reactions (Type IV immune response). This article addresses the clinical and diagnostic aspects of nickel-related reactions in orthodontic patients, based on the literature. A case report highlighting the periodontal, clinical, and histopathologic aspects of an allergic patient in orthodontic treatment is presented.

Solutions to complications of implant therapy.

Restorative dentists face challenges when implant dentistry is performed without a surgical template. Manufactured component parts (particularly screws, gold cylinders, and the implant bodies themselves) can also cause problems during these procedures. These problems will occur regardless of the mode of retention used for the prosthesis, since the same metals are involved and nearly all implant restorations have a screw somewhere. Managing these complications is essential to avoid treatment failures.