Amalgam ‘allergy’ leads to claim

03 November 2022
Paula Conwell, Litigation Solicitor at Dental Protection, details a claim of negligence which was later taken to trial.

A hygienist saw patient Ms H and identified a lesion on her tongue. The hygienist referred Ms H to the dentist and he offered to refer her to an oral maxillofacial surgeon. However, Ms H arranged a private consultation with consultant oral and maxillofacial surgeon Dr J and she was seen the following day.

Dr J noted a thickening of the tissues on the tongue and arranged for Ms H to undergo a biopsy.  The biopsies were performed a few weeks later. 

Based on the reports of the pathologist who carried out the biopsies, the condition was diagnosed as lichen planus, a rash-like condition thought to be autoimmune in nature, which can come and go. Dr J explained this to Ms H before referring her back to her dentist to monitor the condition. Dr J told Ms H that he would be happy to see her again if there were any further problems, and if the area became painful or sore or ulcerated.

Ms H did not return to Dr J.

Ms H attended hospital a year later, reporting that she had a two-year history of pain and tenderness to the left side of her tongue since having amalgam fillings. She was referred for biopsy.

The report on the biopsy identified a “lichenoid inflammation” and she was advised to have the amalgam fillings removed. The fillings were removed and Ms H’s tongue subsequently healed.

Ms H made a claim against Dr J, alleging he had negligently failed to diagnose a lichenoid reaction to amalgam fillings, which had been placed at LL6 and LL7 three and two years prior to seeing him, respectively.

How did Dental Protection assist?

The claim was investigated and an expert instructed in the same discipline as Dr J to provide an opinion on liability. The expert evidence was supportive and the claim against Dr J was defended.

A barrister was then instructed to draft the defence, responding to the allegations raised by Ms H in the Particulars of Claim. I also made an application for the specific discovery of various documents, including the medical records referred to in Ms H’s witness statement. 

Disclosure of these further documents assisted Dr J’s defence and weakened Ms H’s credibility as a witness, as they contradicted various statements in her witness evidence – in particular relating to the duration of her symptoms.

The case went to trial.

The trial

At the trial, the judge had to determine whether:

1. Dr J had been negligent in diagnosing Ms H with lichen planus and

2. He should have informed Ms H that removal of the amalgam fillings may improve her condition whatever the diagnosis.

Ms H’s expert had the opinion that a reasonable and responsible body of consultant maxillofacial surgeons would have diagnosed a lichenoid reaction.

However, this is not the test for breach of duty. The test for breach of duty is set out in Bolam v Friern Hospital Management Committee [1957] 1 WLR 582.

Did Dr J reach a diagnosis that no reasonable and responsible body of consultant oral and maxillofacial surgeons would have reached?

When Ms H saw Dr J, she did not tell him that she had experienced discomfort since the placement of amalgam fillings two years previously. She also told Dr J that she had no allergies and that she had experienced symptoms for a period of nine months. 

In the form that Ms H completed for the private insurance referral, which was completed the day after she saw Dr J, she referred to symptoms being present for one month.

Expert evidence

Ms H’s expert stated that lichen planus is usually bilateral and not unilateral as in Ms H’s case, and the more likely diagnosis was a lichenoid reaction.

The consultant pathologist who reported on the biopsies, and who was aware that these had been taken unilaterally, positively and conclusively concluded that the condition was lichen planus.

The experts agreed in their joint meeting that lichen planus may be unilateral.

Ms H’s expert had the opinion that she ought to have been informed that removal of the amalgam fillings may improve her condition and it was a breach of duty not to do so.

In the opinion of our expert, if the diagnosis was oral lichen planus rather than lichenoid tissue reaction, replacement of the amalgam has little effect.

In our expert’s opinion Dr J treated Ms H appropriately and a body of maxillofacial surgeons would have done exactly the same.

Dr J provided Ms H with advice to return. Ms H did not see Dr J again, she did not consult her GP at all and she did not return to her dentist seeking further referral until a year later.


Ms H alleged that had she been diagnosed with a lichenoid reaction to amalgam fillings, it is likely they would have been removed and replaced. Lichen planus and lichenoid reaction are conditions that are managed by general dental practitioners. The experts agreed that it was reasonable and appropriate for Ms H to be discharged into the care of her general dental practitioner.

There was no evidence that she would have had the fillings removed any earlier than she did.


The judge did not find Ms H’s evidence reliable and found that she had overstated the extent and period of pain. In contrast, the judge found Dr J’s evidence was delivered in a measured and considered manner and that he did not avoid issues that were put to him in cross-examination, some of the issues of which he accepted.

In considering the joint experts report the judge noted that there was significant agreement between the experts. The differences being Ms H’s expert’s opinion that Dr J should have given a differential diagnosis of lichenoid reaction and that it was a breach of duty to not have advised Ms H of the possibility of the amalgam fillings, causing the lesion on Ms H’s tongue and cheek. 

In our expert’s opinion it was not a breach of duty to advise Ms H of the amalgam fillings because Ms H had not returned to see Dr J. Furthermore, with a diagnosis of oral lichen planus, removal of the amalgam has little effect. 

The judge referred to Ms H’s expert’s misquoted statements made in a medical paper. Ms H’s expert incorrectly stated that the paper recommended the removal of amalgam fillings. The judge also referenced the medical paper our expert had referred to in his report, of there being no clear evidence that with either diagnosis patients benefited from amalgam fillings being replaced.

The judge found that once it had been decided by Ms H that the amalgam fillings were the cause of the discomfort, this then led to the diagnosis of a lichenoid reaction and criticisms were then made, in hindsight, of Dr J’s diagnosis and treatment 14 months earlier.

The judge preferred the evidence of our expert than that of Ms H. The main reason being that Ms H’s expert had not applied the correct legal test as to whether Dr J’s treatment was such that no reasonable and responsible body of consultant maxillofacial surgeons would have undertaken it.

The judge did not find that Dr J’s treatment fell below the standard expected, and dismissed Ms H’s claim on the basis that he was not satisfied that Dr J had breached his duty of care to Ms H.

Learning points

Despite our prospects of success before trial being assessed at 50%, we fully supported Dr J in this case and defended the claim to trial.

Litigation is unpredictable and often conferences, settlements and discontinuances happen at the last minute before trial. In this case it was slightly surprising that Ms H had been prepared to pursue her claim to trial.

These case studies are based on real events and provided here as guidance. They do not constitute legal advice but are published to help members better understand how they might deal with certain situations. This is just one of the many benefits Dental Protection members enjoy as part of their subscription. 
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