A metallic taste in the mouth: dental causes and when to see a dentist

A metallic taste in the mouth is a change in taste perception known medically as dysgeusia. Sometimes, the cause is simple and temporary, such as a respiratory infection or taking certain medicines. In other cases, a metallic taste may be a sign of dental problems that require treatment.

A metallic taste can occur in people of any age, but it is more common in patients suffering from gum disease, dental infections, chronic illnesses or those undergoing complex medical treatments. Furthermore, people with poor oral hygiene are more likely to notice changes in taste.

Identifying the cause is important because treatment varies depending on the underlying factor. A dental check-up can help to quickly identify dental problems and rule out more complex medical conditions. 

A metallic taste is a change in taste perception, characterised by the sensation of metal in the mouth. It may be temporary or persistent and can occur regardless of the food consumed.

From a physiological point of view, the sensation occurs when the taste receptors are affected by>

• local inflammation;
• infections;
• medicines;
• metabolic imbalances.

“Taste buds work in conjunction with olfactory receptors to identify aromas and flavours. When one of these mechanisms is affected, the perception of taste can become distorted. In some cases, a metallic taste is accompanied by a dry mouth or a change in sensitivity to certain foods,” explains Dr. Anita Zodilă, a specialist in periodontology at the DENT ESTET Unirii clinic.

It is important to distinguish a metallic taste from other unpleasant sensations, such as a bitter or sour taste. These can have different causes, including digestive disorders, gastro-oesophageal reflux or hormonal changes, whilst a metallic taste is frequently associated with dental problems, medication or systemic conditions. 

Tooth decay

Advanced tooth decay can encourage the build-up of bacteria and inflammation of the tissues surrounding the tooth. The by-products of bacterial activity can alter the oral environment and cause an unpleasant taste, including a metallic one.

“Patients are sometimes surprised to learn that a seemingly minor cavity can affect their sense of taste. This symptom often disappears once the underlying dental cause has been treated” – Dr. Anita Zodilă.

Dental infections (dental abscess)

Dental infections are one of the most common local causes of a metallic taste. A dental abscess can lead to the build-up of pus and damage to neighbouring tissues, which alters the patient’s sense of taste.

At the same time, gum infections such as gingivitis and periodontitis can lead to bleeding and inflammation. The presence of blood in the mouth can create the characteristic sensation of a metallic taste.

In addition to a changed sense of taste, patients may experience pain, tooth sensitivity, swollen gums or unpleasant breath.

Dental restorations and reactions to certain materials

Old or poorly fitted dental work can promote bacterial retention and the development of local inflammation, leading to changes in taste.  

In rarer cases, certain dental materials can trigger electrochemical reactions in the mouth, which may be perceived as a persistent metallic taste.

A dental assessment is essential for identifying these situations and determining whether the restorations need to be replaced.

Periodontal problems

Gingivitis and bleeding gums are symptoms of periodontal disease and one of the main causes of a metallic taste in the mouth.

“As the inflammation progresses, bacteria accumulate in the periodontal pockets and contribute to halitosis and changes in taste. Patients may also experience gum sensitivity, gum recession or tooth mobility.” – Dr Anita Zodilă.

Early treatment can prevent complications and eliminate the associated symptoms.

Find out about the benefits of laser periodontal treatment.

Poor oral hygiene

Inadequate brushing and the build-up of bacterial plaque and tartar encourage the growth of bacteria responsible for inflammation and unpleasant odours. These changes can also affect the sense of taste.

Maintaining proper oral hygiene contributes both to dental health and to preserving a normal sense of taste.

Stomatitis and inflammation of the oral mucosa

Inflammation of the oral mucosa can alter taste and cause a burning sensation or discomfort. Stomatitis is caused by infections, dental trauma or systemic conditions.

Oral thrush – a fungal infection commonly found in people with weakened immune systems or following a course of antibiotics – may be accompanied by a metallic or unpleasant taste.

Furthermore, mouth ulcers and oral lesions can affect the taste buds and cause temporary changes in taste.

A dental check-up is recommended when:  

• A metallic taste persists for more than two weeks. This persistence may indicate a dental or medical problem requiring treatment.
• Associated symptoms such as toothache, swollen gums, increased sensitivity or frequent bleeding occur. These symptoms often suggest the presence of an infection or periodontal disease.
• The unpleasant odour (halitosis) does not go away with oral hygiene
• Gum recession occurs.

A thorough clinical examination of the oral cavity is required to make a diagnosis. The dentist assesses:

• the health of the teeth and gums;
• how well any dental work fits;  
• any signs of infection or inflammation.

Depending on the situation, dental X-rays and interdisciplinary consultations may be recommended. If there is no obvious dental cause, the patient may be referred for blood tests or further investigations to identify a systemic condition.

Dental treatment options

Treatment is tailored to the identified cause:

• fillings in the case of tooth decay;
• root canal treatment or drainage to remove dental infections;
• professional scaling to reduce inflammation;  
• periodontal therapy for gum and periodontal conditions;
• replacement of old prosthetic work. 

Thorough oral hygiene is the most effective way of preventing many dental conditions associated with a metallic taste. Brushing twice a day, flossing and regular check-ups help to maintain good oral health.

Adequate hydration is equally important, as a dry mouth can exacerbate changes in taste. Drinking enough water helps to maintain a healthy oral environment.

Regular visits to the dentist allow for the early detection and treatment of dental problems before they cause persistent symptoms. 

1. Mayo Clinic – Metallic taste: Causes and treatment
2. Cleveland Clinic – Dysgeusia (Taste Disorders)
3. National Institute of Dental and Craniofacial Research (NIDCR) – Taste Disorders
4. American Dental Association (ADA) – Oral Health Topics
5. National Health Service (NHS) – Metallic taste in the mouth