Dementia and oral health: essential knowledge for the dental team

As an aging population brings dementia to the forefront of the public health agenda, Sakina Syed explains everything dental professionals need to know about the condition and its bidirectional relationship with oral health.

Dementia is a pressing global public health burden and challenge, affecting individuals, impacting families, carers and healthcare systems. While much attention is rightly given to cognitive decline and behavioural changes, oral health is often overlooked in the vulnerable elderly population. By recognising the unique challenges this group faces and adapting care accordingly, dental professionals can play a crucial role in preserving oral health, as well as dignity, comfort and quality of life.

This article explores the complex relationship between dementia and oral health, highlighting the challenges faced by patients and carers and emphasising the need for greater awareness, education and integrated care approaches across the healthcare system. You may find yourself treating a patient with early onset dementia, providing support to a carer or family member or providing care as part of the wider healthcare network in a community or a hospital setting.

What is dementia?

In the UK, dementia represents a significant and growing public health concern. It is estimated that around 900,000 people are currently living with dementia, projected to rise to over 1.6 million as the population ages.

The economic impact is considerable, with the cost of dementia care estimated at over £25 billion per year. However, it’s likely to be greater, as many carers are family members rather than employees. These figures highlight the need for improved awareness, early diagnosis and integrated care – including a stronger focus on oral health within this vulnerable population.

Dementia is an umbrella term for a collection of cognitive diseases. There are, in fact, over one hundred different types of dementia, with the most common being Alzheimer’s disease, vascular dementia, frontotemporal dementia and Lewy body dementia. Each has some distinct characterised symptoms as well as some that overlap, but an individual can also suffer from a combination of two diseases together, such as Alzheimer’s and vascular dementia.

Alzheimer’s disease (AD)

This is the most common type of dementia and involves plaques and tangles in the brain due to two proteins, amyloid and tau. They form clumps or plaque buildup in the brain, which leads to confusion and memory loss. AD is a progressive, irreversible and incurable disease.

Vascular dementia

Vascular dementia is caused by impaired blood flow to the brain, like multiple small mini strokes, which are hard to identify and diagnose. It can affect different parts of the brain. It has similar symptoms to AD, but also affects mobility, speech and personality changes. In later stages, bladder/bowel incontinence issues can occur.

Frontotemporal disease (Pick’s disease)

Several types of dementia affect the brain’s frontal and temporal lobes, which influence personality and behaviours, including language. Protein deposits build up in the cells in the frontal and temporal lobes. It is the third most common type of dementia seen affecting people in the 45-65 age bracket, and they often develop a desire for sweet foods.

Lewy body dementia

Named due to abnormal protein deposits, or Lewy bodies, that build up inside brain cells and disrupt communication. It affects personality and speech, with symptoms resembling Parkinson’s disease and AD, with associated memory loss and visual hallucinations.

Mixed dementia

A combination of two or more dementia types, such as AD and vascular dementia.

How does oral health impact dementia?

As dementia progresses, individuals may struggle with daily oral care, experience reduced manual dexterity or become resistant to treatment due to confusion or anxiety. This can lead to a rapid deterioration in general health and oral health, including increased risk or progression of periodontal disease, dental caries, pain, infection and difficulties with eating and communication.

Common oral health challenges include poor plaque control, increased risk of dental caries (root caries) and periodontal disease, xerostomia (often linked to medications and dehydration), ill-fitting dentures, oral infections, and undiagnosed oral pain. Communication difficulties may mean discomfort goes unreported, while changes in diet, such as a preference for softer, carbohydrate-rich foods, further increase disease risk. In later stages, access to dental care may also become more limited, especially for those in long-term care or housebound.

Poor oral hygiene can lead to the accumulation of harmful plaque bacteria in the mouth, which in turn can contribute to periodontal disease. Specific oral bacteria, such as Porphyromonas Gingivalis, have been found in the brains of Alzheimer’s patients, raising the possibility that it may play a role in the development of the disease.

Dementia and the oral microbiome

Studies have indicated that this bacterium can enter the bloodstream through inflamed periodontal pockets and travel to the brain, once it enters systemic pathways, potentially causing inflammation and damage to brain cells; but other routes are also possible, such as peripheral nerve pathways via a virus (Huang et al, 2025; Dominy et al, 2019).

Chronic inflammation is a key factor in the progression of Alzheimer’s disease. Periodontal disease indicates inflammation in the periodontium. This can trigger a systemic inflammatory response that affects the rest of the body, including the brain. Over time, this inflammation may contribute to the neurodegenerative processes seen in Alzheimer’s disease.

Toxins produced by oral bacteria can have detrimental effects on the brain. Studies have suggested that these toxins may promote the accumulation of amyloid plaques, which are a hallmark of Alzheimer’s disease. Amyloid plaques are clumps of protein that build up in the brain, disrupting communication between nerve cells and leading to cell death (Sun and Mianxiang, 2025; Tagliafico et al, 2024).

Periodontal disease and dementia

The association between periodontal disease and dementia/cognitive impairment continues to receive increasing attention. However, whether periodontal disease is a direct risk factor for dementia/cognitive impairment is still uncertain.

Increasing evidence indicates that inflammation plays a major role in dementia/cognitive impairment, with the contribution of microbes (Huang et al, 2025; Said-Sadier et al, 2023).

Some case-control studies have shown that patients with infections were two times as likely to suffer from dementia as persons without infections (Said-Sadier et al, 2023).

Periodontal disease is not only a common chronic infectious and inflammatory oral disease but also contributes to systemic diseases.

In a meta-analysis, it was concluded that periodontitis was associated with cognitive impairment, and subjects with moderate or severe periodontitis were at greater risk of developing dementia (Said-Sadier et al, 2023).

Impact on oral hygiene

Tasks that individuals with dementia may once have been able to complete independently can become difficult. They can:

• Forget the importance of cleaning their teeth
• Not remember how to clean them or what to use
• Reduced dexterity can cause difficulty holding the toothbrush or unscrewing/flipping the toothpaste lid hard
• The process of moving the toothbrush into the mouth can be forgotten and confusing
• Suffer from mucositis and cannot explain why the mouth is painful and sore
• Experience sensory disturbance and not like the taste/texture or feeling of certain flavoured toothpaste or the vibrations of an electric toothbrush.

How does dementia impact the mouth?

Changes in eating habits

• Playing with food – not eating from certain utensils/plates
• Increased or decreased appetite
• Altered meal timings, including night-time eating
• Increased risk of dental caries and periodontal disease
• Difficulty chewing or swallowing food
• Reduced nutritional intake and risk of malnutrition
• Requirement for nutritional supplements, some of which may contain high sugar levels.

Taste alteration

• Increased desire for sweet items increases the risk of dental caries
• Consistency and texture of foods desired can change
• May want more salt added to foods.

Tongue changes

• Increased risk of oral candida due to antibiotics or systemic infections
• Furring of the tongue
• Discolouration of the tongue
• Altered sensation of the tongue.

Xerostomia

• Medication-induced dry mouth
• Increased risk of root caries and oral infections
• Denture discomfort and stomatitis
• Reduced comfort when eating or speaking.

Swallowing

• Dysphagia affecting any stage of the swallowing process
• Holding food or fluids within the mouth
• Difficulty swallowing certain food consistencies
• Increased risk of aspiration and pneumonia.

Increased caries risk

• Reduced salivary flow
• Increased sugar intake
• Elevated bacterial microbes.

Increased periodontal disease

• Poor oral hygiene and elevated bacterial plaque
• Affecting the periodontium, periodontal pockets and bone loss
• Difficult to stabilise and manage.

Denture problems and mucositis

• Denture stomatitis (inflammation) is a major issue with denture-wearing patients in long-term care
• Denture care can be overlooked in care settings, by carers or in long-term hospital inpatients due to a lack of training
• Lost dentures during hospital stays cause functional disabilities.

Oral candida/thrush

• Associated with pain, weight loss and malnutrition
• Increased risk following antibiotic use and systemic illness
• Can negatively affect overall well-being and quality of life.

What impact do these changes have on individuals with dementia?

Oral challenges in dementia can affect nutrition, overall wellbeing and daily life.

Individuals living with dementia may experience either an increased or a decreased appetite and general functional disabilities. This fluctuation can be influenced by meal timings and changes in taste, with an increased desire for sweets or saltier foods, but also mucositis, soreness or discomfort in the mouth. This can be due to poor oral hygiene, plaque-retentive areas, but also non-bacterial related, such as xerostomia and dehydration.

Dysphagia or swallowing difficulties are a critical concern. Pocketing food in the buccal mucosa or under the tongue, difficulty swallowing lumpy foods or thin liquids, and the risk of choking are common. When coupled with infections, such as kidney infections and urinary tract infections, vomiting or aspiration of food/liquid into the lungs, it becomes a pressing medical problem.

Increased medication use can result in xerostomia, or dry mouth, which not only affects comfort due to the mouth becoming sore but also dry lips, raising the risk of dental caries and reduced salivary flow and infections such as oral candida.

How can dental professionals help?

Dental professionals play a vital role in addressing these challenges through prevention, early intervention and collaborative care. Equally important is empowering carers, who are often family members, with the knowledge and confidence to support daily oral care, alongside working closely with wider healthcare teams to ensure a holistic approach.

If individuals require support or their oral care needs to be completed by a carer or family member, the following points can help.

• Setting a reminder or written reminders can help in the early stages to prompt memory
• Toothbrushing together if living in the same home
• Breaking down the steps of how to use a toothbrush and what equipment to use
• Use simple, clear instructions
• Support the head and jaw when toothbrushing someone else’s teeth
• Use music as a distraction technique
• Encourage hydration and lip care
• Tailoring oral hygiene to the stage of dementia
• Consider soft manual toothbrushes or sensitive electric toothbrushes
• Power water flossers and soft-textured interdental brushes
• Mouthwashes as adjuncts to aid plaque biofilm removal
• Mild formulated toothpastes and gels.

During the later stages of dementia, individuals may become non-verbal and unable to communicate pain effectively. As a result, oral discomfort may go unrecognised, leading to untreated disease, distress and prolonged hospital admissions. Non-verbal indicators of pain may include facial grimacing, agitation, aggression, restlessness, refusal to eat or resistance to oral care. Many healthcare settings now utilise non-verbal pain assessment tools to help identify discomfort in individuals with advanced dementia (Tagliafico et al, 2024).

Addressing the oral challenges of dementia requires a compassionate and informed approach, keeping in mind the physical, emotional, and social impact of the condition.

Improving outcomes requires a more integrated healthcare model in the UK, where oral health is embedded within dementia care pathways, ensuring dignity, comfort and overall well-being are prioritised for this growing population.

References

1. Huang, Z, Hao, M, Sh,i N, Wang, X, Yuan, L, Yuan, H and Wang X. Porphyromonas gingivalis: a potential trigger of neurodegenerative disease. Front. Immunol. 16:1482033. doi: 10.3389/fimmu.2025.1482033 (2025).
2. Dominy, Stephen S et al. Porphyromonas gingivalis in Alzheimer’s disease brains: Evidence for disease causation and treatment with small-molecule inhibitors.Sci. Adv.5,eaau3333(2019).
3. Sun, Qiyin and Li, Mianxiang. Association between periodontitis and cognitive impairment in older adults: A cross-sectional study of the National Health and Nutrition Examination Survey, Clinical Epidemiology and Global Health, Volume 33 (2025).
4. Tagliafico, L, Maizza, G, Ottaviani, S, Muzyka, M, Rovere, FD, Nencioni, A and Monacelli, F. Pain in non-communicative older adults beyond dementia: a narrative review. Front. Med. 11:1393367. doi: 10.3389/fmed.2024.1393367 (2024).
5. Said-Sadier, N, Sayegh, B, Farah, R, Abbas, LA, Dweik, R, Tang, N, Ojcius, DM. Association between Periodontal Disease and Cognitive Impairment in Adults. Int J Environ Res Public Health. Mar 7;20(6):4707. doi: 10.3390/ijerph20064707. PMID: 36981618; PMCID: PMC10049038 (2023).
6. www.denmentiauk.org
7. Mouth Care Matters Toolkit https://aqua.nhs.uk/wp-content/uploads/2023/02/Mount-Care-Matters-Toolkit-for-improving-mouth-care-in-hospitals.pdf

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