**5. Diagnosis and treatment**

The figure shows the flow chart for the diagnosis and treatment of dental metal allergy.

Fig. 8. Flow chart for diagnosis and treatment of dental metal allergic disease.

#### **5.1 History taking**

The primary goal of the questions for the metal allergy patients is to obtain a past history concerning their reaction to the metallic items that might be responsible for the allergic reaction. The following case highlights the information that leads to suspecting the patient of having a dental metal allergy.


dermatitis, with patients exhibiting no atopic diathesis and a low value for the immunoglobulin E (IgE) radioimmunosorbent test. Absorbed allergen is spread by blood flow and causes the eczema and urticaria on general skin, and in some cases is associated with itching, heat and painful sensations. Instead of referring to this as generalized eczema, the symptoms for this could be referred to as atopic dermatitis with metal allergy. The name

Typical symptoms of atopic dermatitis are chronic eczema with an itching sensation. Serum IgE is generally increased in these patients, and there is a repeated advancement to remission of the symptoms. Intractable cases sometimes exhibit a positive reaction to a metal reagent when using the patch test. In such cases, removing the intraoral metal restorations that contain the allergy-positive metal could lead to a remission of the symptoms. Since the skin barrier function of atopic dermatitis patients is compromised and not enough to prevent infection and sensitization, metal allergies tend to complicate these types of cases.

The figure shows the flow chart for the diagnosis and treatment of dental metal allergy.

Fig. 8. Flow chart for diagnosis and treatment of dental metal allergic disease.

2. React to metals in ornaments and daily necessities, and is hard to cure.

The primary goal of the questions for the metal allergy patients is to obtain a past history concerning their reaction to the metallic items that might be responsible for the allergic reaction. The following case highlights the information that leads to suspecting the patient

1. Having incurable skin trouble with red spots, eczema, and vesicles, with ineffective

of this disease is still being debated at the present time.

**4.7 Atopic dermatitis** 

**5. Diagnosis and treatment** 

**5.1 History taking** 

of having a dental metal allergy.

dermatological treatment.

3. After dental treatment with metal material, skin and intraoral symptoms developed or became incurable.

All of the patients were given recommendations to undergo a patch test for the purpose of diagnosing dental metal allergy. As an alternative in vitro examination, lymphocyte activation tests can also be used. However, since lymphocyte activation tests are not available for every metal element, the patch test should be considered as the first choice for confirmation of the diagnosis.

#### **5.2 Patch test**

Patch testing should be done according to criteria from the International Contact Dermatitis Research Group (ICDRG). Examination plasters containing the test reagent were attached to the back or the arm of the patient for 48 hours (Groot, 2008). After waiting for one hour after the plaster removal and the effect of the stimulation was gone, changes on the skin surface were evaluated according to the ICDRG criteria (Jean-Marie Lachapelle&Maibach, 2009). The same evaluations were repeated 72 hours and one week later. Since some of the metal reagents tended to exhibit a high reaction 7 days after plaster attachment, a minimum of a one-week test period is required for these tests (Davis et al., 2008). In addition, since aluminum in the Finn Chamber reacts with Hg2+ and produces hydrochloric acid, this chamber cannot be used for the HgCl2 reagent.

#### **5.2.1 Metal reagents**


The following metal reagents are the primary reagents used for a patch test (Table. 3).

Table 3. Test reagents

#### **5.3 Treatment of dental metal allergy**

If patients exhibited positive reactions to any of the metal reagents of the patch test, intraoral restorations that could potentially contain metal elements should be examined. Since most of the dental metal material is an alloy metal, simply inspecting the material is not adequate for distinguishing the metal elements. Thus, a non-invasive analysis technique that extracts micro dust from the intraoral restoration and examines it with an Electron Probe Micro-Analyzer (EPMA) or an X-Ray Fluorescence Spectroscopy (XRFS) needs to be performed (Minagi et al., 1999, Suzuki, 1995, Uo&Watari, 2004). For the extraction of metal dust, a tungsten-carbide bur is sometimes used to scrape the metal restoration (Minagi et al., 1999, Suzuki, 1995). However, to ensure there were minimal invasions of the site, we employed the following simple silicone point technique.

Dental Metal Allergy 99

Fig. 11. XRF spectroscopy analyzer and the CCD camera view of the EDX900.

dental treatment to remove the inadequate metal restorations.

**5.4 Removal of metal restorations** 

2. Restorations located near the lesion site.

occlusion or with the proximal teeth.

priority should be as follows.

7. Results of the XRF analysis indicated whether or not the intraoral restoration involved an allergy-positive metal element. Since this technique was only available for restorations that were exposed on the surface of a tooth, materials used to build up a tooth, luting cements and root canal fillings could not be examined without having to remove the outer restorations. If the patients are able to identify the dental clinic where the original work was done, then the clinic can be contacted and the name of the metal products used determined before the materials are removed. If information on the actual metal element can be determined, then after informed consent is obtained from the patient, the intraoral metal materials previously utilized can be included in the planning of the subsequent

When removing the restorations that contain allergy-positive metal elements, the removal

4. Two or more restorations with different metal materials that make contact with the

In principle, all restorations with allergy-positive metal elements need to be removed. The build-up material that was used for the inside of the full veneer crown is no exception, as it could be eluted. If the patient does not have an allergy to the acrylic material, composite resin filling and/or a temporary restoration with an acrylic resin can be performed to confirm the effect of removing the metallic materials. For patients with an acrylic allergy, glass ionomer cement can be used as a temporary treatment. After the metal material has been removed, sometimes an almost immediate aggravation of the allergic symptoms is observed. This could potentially be due to the effect of metal dust that was swallowed,

1. Oral restorations with high elutions, such as black-colored amalgam fillings.

3. Restorations that contain a high rate of allergy-positive metal elements.

these devices.

acquired sample can be sterilized using gaseous sterilization so that it can then be mailed to facilities that have a micro analyzer (Fig. 11). Since the analysis conditions of the XRFS are different for each device, we have not described the details for each of


Fig. 9. Disposable polishing point.


Fig. 10. Polypropylene film, virgin metal sample and a Super-Snap Mini Point.

6. XRF spectroscopy analyzer (EDX900, Shimadzu Corporation, Tokyo, Japan) was used for evaluation of the metal element. Using this analyzer makes it possible for the

• A disposable polishing point (Super-Snap Mini Point, Shofu Corporation, Kyoto, Japan)

• Polypropylene film (3520 polypropylene, Spex Chemical Sample Press, Metuchen, NJ,

2. Clean the surface of the intraoral restoration with a dental cleaning brush in order to

3. Attach the Super-Snap to the hand motor and scrub the surface of the metal restoration using a slow speed (1000-2000 rpm). If the antagonistic tooth was restored with a metal material, do not take any samples from the occlusal surface. This will prevent any effect

4. Transfer the metal dust on the surface of the Super-Snap to a cellulose tape strip and

5. The figure below shows pictures of a sample from an intraoral restoration. Micrometal dust on the cellulose tape strip has been covered with polypropylene film. The amount of the extracted sample was about 1 mg and no polishing of the tooth surface was

Fig. 10. Polypropylene film, virgin metal sample and a Super-Snap Mini Point.

6. XRF spectroscopy analyzer (EDX900, Shimadzu Corporation, Tokyo, Japan) was used for evaluation of the metal element. Using this analyzer makes it possible for the

1. For each sample, prepare the following material set:

• Cellulose tape (Sellotape, Nichiban, Tokyo, Japan)

(Fig. 9)

USA)

Fig. 9. Disposable polishing point.

remove the plaque and other stains.

of the metal on the antagonistic tooth.

required after the extraction.

cover the tape strip with polypropylene film.

acquired sample can be sterilized using gaseous sterilization so that it can then be mailed to facilities that have a micro analyzer (Fig. 11). Since the analysis conditions of the XRFS are different for each device, we have not described the details for each of these devices.

Fig. 11. XRF spectroscopy analyzer and the CCD camera view of the EDX900.

7. Results of the XRF analysis indicated whether or not the intraoral restoration involved an allergy-positive metal element. Since this technique was only available for restorations that were exposed on the surface of a tooth, materials used to build up a tooth, luting cements and root canal fillings could not be examined without having to remove the outer restorations. If the patients are able to identify the dental clinic where the original work was done, then the clinic can be contacted and the name of the metal products used determined before the materials are removed. If information on the actual metal element can be determined, then after informed consent is obtained from the patient, the intraoral metal materials previously utilized can be included in the planning of the subsequent dental treatment to remove the inadequate metal restorations.
