Free surface nickel in CE-marked and non-CE-marked spectacle frames

Metal hypersensitivity in patients with orthopaedic implant complications-A retrospective clinical study

BACKGROUND

Hypersensitivity to metals as a cause of implant-related complications has been a subject of controversy. Projections indicate an increase in the frequency of joint replacements of between 300% and 600% by the year 2030; therefore, this issue is of considerable interest.

OBJECTIVE

To evaluate sensitization to implant materials in patients with implant-related complications, to identify allergens, and to clarify whether hypersensitivity is a relevant cause.

METHODS

Patients with implant-related complications or a positive history of contact allergy and planned total joint replacements referred for allergological investigation between 2004 and 2017 were retrospectively analysed.

RESULTS

In total, 311 patients were included. A positive patch test reaction to a metal was seen in 64.4% of preoperative patients and in 54.6% of patients with implant-related complications. Common alloy metals such as cobalt, chromium and titanium gave positive reactions in up to 2.9% of patients with implant-related complications. None of the patients with skin changes had a positive patch test reaction to an implant metal.

CONCLUSION

Other factors, such as the type of replaced joint and mechanical stress, seem to be more relevant for implant-related complications. Sensitization to metals or other materials seems to rarely play a role, and is overestimated.

Cross-sectional observational study exploring clinical risk of titanium allergy caused by dental implants

PURPOSE

Studies have reported cases of metal allergy caused by titanium-containing materials. We wished to clarify the relationship between titanium allergy and dental implants by describing patients who suffered allergic symptoms after they had received such implants.

METHODS

A total of 270 patients who visited a Dental Metal Allergy Clinic at Tokushima University Hospital from April 2010 to March 2014 were the study cohort. Patch testing with 28 types of metal allergens (including four titanium allergens) was undertaken for patients.

RESULTS

A total of 217 patients (80.4 %) exhibited allergy-positive reactions to at least one type of metal allergen. Mercury, palladium, chromium and nickel exhibited a higher prevalence of allergy-positive reactions than other metals. Sixteen patients visited our clinic suffering allergic symptoms after receiving dental implants. Eleven of those patients exhibited allergy-positive reactions for any of the metal allergens, and 4 of these patients had allergy-positive reactions against titanium allergens. The total number of allergy-positive reactions for titanium allergens among all 270 patients was 17 (6.3 %). No patient exhibited a positive reaction only for the titanium allergen.

CONCLUSIONS

The prevalence of allergy-positive reactions for titanium allergens was lower than for other metal allergens. We suggest examination of pre-implant patients who have a history of hypersensitivity reactions to metals.

The fine scratches of the spectacle frames and the allergic contact dermatitis

Background

Spectacle contact allergy is not infrequent. The fine scratches on the spectacle frames which may play a role in the sensitization to the potential allergenic components have not been studied.

Objective

We sought the relationship between the scratches on the spectacle frames and the allergic contact dermatitis (ACD) in the Republic of Korea.

Methods

A total of 42 Korean patients with ACD at the spectacle contact sites were enrolled. Their spectacle frames were examined with the dimethylglyoxime (DMG) test and analyzed by the scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Patch tests (thin-layer rapid use epicutaneous test [TRUE tests]) were performed to identify the skin allergens.

Results

The DMG-positive spectacle frames were identified in 78.5% of the frames. The SEM results showed that there were more scratches on the skin-contacting parts of the spectacle frames than the non-skin-contacting parts of the same frames. In the EDS findings, the mean nickel content (weight, %) of the spectacle frames was 15.7±5.5, and the mean chromium content was 20.3±3.4 at the skin-contacting parts. In the TRUE tests, nickel sulphate was the most common allergen (31 cases, 73.8%), and potassium dichromate was the second (9 cases, 21.4%). Three patients presented simultaneous positive reactions with nickel sulphate and potassium dichromate.

Conclusion

Minor visible and non-visible fine scratches on the spectacle frames may present the provocation factors of the ACD. Nickel sulphate was the most common allergen suspected of provoking the spectacle frame-induced ACD, followed by potassium dichromate.

Materials and allergens within spectacle frames: a review

The materials that have been reported as causing allergic contact dermatitis within spectacle frames are identified, and their most likely location on the frame is highlighted. The lack of any real control over spectacle frame quality and content is indicated to be a problem, as is the difficulty in determining the true source of many frames. Much of the information must be obtained from anonymous sources in the industry, historical 'common knowledge' of indeterminate source or reports of dermatological problems.

Das Allergiepotenzial von Implantatwerkstoffen auf Titanbasis

AIM

The aim of this investigation is to evaluate the allergic potential of titanium and titanium alloys for surgical implant applications.

MATERIALS AND METHODS

Discs cut from rods supplied by five different titanium suppliers in several diameters were investigated. The samples were cp-Titanium as well as Ti6Al4 V and Ti6Al7Nb, 6 mm thick with a diameter of between 6 and 60 mm. The material was checked by optical spectral analysis.

RESULTS

In all samples except iodidtitanium, a Nickel content of 0.012-0,034 wt% could be detected.

CONCLUSION

The low nickel content in the implant material results from the production process. The nickel atoms are in solid solution in the titanium lattice. Nickel allergic patients may develop hypersensitivity reactions even due to this low nickel content. Hence, this reaction may be falsely attributed to the titanium material itself. Measurements of ion concentration in the body are helpful for quantifying the maximum content of nickel in titanium materials for surgical implant applications. In addition, technical questions related to the production of nickel free titanium materials for allergic patients have to be solved.

Nickel on the Swedish market. Follow-up after implementation of the Nickel Directive

The Nickel Directive aims at the prevention of sensitization and elicitation of nickel dermatitis. It limits nickel release from, and nickel content in, certain items. The Directive came into full force by July 2001. The aim of this study was to investigate the frequency on the market of items that release nickel and of nickel content in piercing posts, 2 years after coming into force of the Directive. Of special interest was to study changes compared to the situation in 1999, when a baseline study had been carried out. Nickel release from 786 items covered by the Nickel Directive was tested with the dimethylglyoxime (DMG) test, and nickel content in 18 piercing posts was analysed. Nickel release was shown from 8% of items intended for direct and prolonged contact with the skin, and 17% of the piercing posts contained too much nickel, a decrease compared to 1999. There has been significant adaptation to the requirements of the Nickel Directive. The DMG test is useful for screening for nickel release and for monitoring the market. Provided there is further adaptation to the requirements, the risk of sensitization and elicitation of nickel dermatitis will be significantly reduced.