Overview

In the hustle and bustle of the fast-paced world and modern life, stress is an inevitable companion. While its effects on general health are widely recognized, its impact on oral health is often overlooked.  Stress can lead to behavioural and physiological changes that increase the risk of oral health issues, including tooth decay (dental caries). By uncovering this connection, we can raise awareness and provide insights into preventive measures to maintain a healthy mouth even in stressful times.

Stress

Stress can be defined as any real or perceived threat to an individual's physical or mental well-being, triggering a series of physical and behavioural responses to maintain balance in the body.¹ People may encounter various sources of current stress, ranging from interpersonal to environmental and material.

These stressors are typically categorised into four types: major life events (such as a family member's death), ongoing environmental pressures (like safety concerns in one's neighbourhood), role-related stressors (such as challenges within a workplace hierarchy), and daily hassles (stress arising from routine activities, like daily commutes).²

Impact of stress on the body

Stress significantly impacts the body through a series of complex physiological mechanisms. The theory of allostatic load explains how stress affects the human body. When a person is exposed to stress for a long time, the systems that help the body cope with stress [like the central nervous system, the autonomic nervous system, and the hypothalamus-pituitary-adrenal (HPA)  axis] begin to wear down.¹

Chronic stress causes the autonomic nervous system and the HPA axis to become unbalanced. This leads to the excessive release of the hormone cortisol, which over-stimulates certain receptors in the body and disrupts the function of key neurotransmitters like adrenaline, noradrenaline, and serotonin.¹ Chronic stress exposure decreases immune response and leads to chronic inflammation through interactions among the immune, neurological, and endocrine systems.

While stress triggers psychological (related to the human mind and thoughts) and biological responses crucial for adaptation and survival in challenging circumstances, its prolonged presence can lead to detrimental effects. Stress is ubiquitous and can impact individuals across all social strata, but its effects vary significantly from person to person.²

Impact of stress on oral health

A link between stress and oral diseases has been suggested for a few decades. Nevertheless, stress is still not widely acknowledged as a significant risk factor for these diseases. Poor oral health has been associated with common psychological disorders like depression, generalised anxiety disorder, panic disorder, Obsessive-Compulsive Disorder (OCD), Post-Traumatic Stress Disorder (PTSD), phobia, eating disorders, etc. 

Chronic stress can potentially contribute to the long-term development of oral diseases through two distinct pathways. Firstly, it may drive individuals to adopt unhealthy coping mechanisms such as substance use (including illicit drugs, alcohol and tobacco), unhealthy lifestyle habits (like excessive sugar intake and neglect of oral hygiene), and sedentary behaviour, which can foster oral disease. Secondly, chronic stress can increase allostatic load, leading to dysfunction in critical physiological systems essential for maintaining homeostasis. This can ultimately affect the underlying mechanisms involved in disease progression.³

The oral mucosa is highly sensitive and reactive to stressors. Oral diseases can be direct or indirect manifestations of emotional problems or conflicts, often expressed as psychosomatic disorders. Common oral problems related to stress include:^6,7 

• Tooth decay
• Chronic periodontitis
• Necrotizing Gingivitis (ANUG)
• Aphthous ulcers
• Oral lichen planus
• Xerostomia
• Burning mouth syndrome
• Erythema multiforme (EM) 
• Mucous membrane pemphigoid (MMP)
• Recurrent herpes labialis (RHL)
• Dysgeusia
• Atypical odontalgia
• Temporomandibular Joint Disorder (TMJ)
• Myofascial Pain Dysfunction Syndrome (MPDS)
• Nutritional deficiencies presenting as angular cheilitis, oral candidiasis, glossitis and oral mucosal ulceration (due to poor diet or self-induced vomiting as in bulimia nervosa)
• Teeth abrasion (brushing repetitively in Obsessive Compulsive Disorder)
• Erosion on the palatal surfaces of teeth (due to self-induced vomiting as in bulimia nervosa, anorexia and gastro-esophageal reflux from high usage of alcohol in depression)
• Parafunctional habits like bruxism, thumb-sucking, nail-biting, and biting of oral mucosa (lips, cheeks, tongue), object biting/sucking⁵ which can lead to dental issues like compromised periodontal health, oral lesions, tooth wear, tooth decay, jaw pain, and even cracked or fractured teeth⁵

Impact of stress on tooth decay

Physiological changes

1. Psychosocial factors such as stress, depression, and anxiety are strongly associated with oral diseases, impacting oral health by reducing salivary flow and altering saliva composition due to corticosteroid effects on major salivary glands. Xerostomia, characterised by a reduced rate of salivary flow, leads to plaque accumulation and a heightened risk of tooth decay by diminishing saliva's natural cleansing and protective functions.^3,7

Additionally changes in saliva, such as reduced buffering capacity and alterations in oral microorganism balance, can create an environment conducive to cariogenic (dental caries-causing)bacteria’s growth and increase the risk of tooth decay.⁴ 

2. Individuals experiencing psychological stress often have increased secretion of catecholamines (adrenaline, noradrenaline), which reduces salivary flow.

3. Medications like antidepressants [Tricyclic antidepressants (TCAs), Selective serotonin reuptake inhibitors (SSRIs), etc.] and antipsychotics (Olanzapine, Clozapine, Haloperidol, Quetiapine, Risperidone, Donepezil) interfere with the autonomic nervous system (ANS) signalling involved in the regulation of saliva production and cause dry mouth.⁸

4. Eating disorders like bulimia nervosa can affect the parotid gland, leading to decreased saliva production in these patients.⁷

5. Dental anxiety is characterised by fear and stress related to dental visits and procedures. Certain mental illnesses, including generalised anxiety disorder, depression, post-traumatic stress disorder (PTSD), bipolar disorder, and schizophrenia, can heighten the risk of individuals experiencing dental anxiety.⁷ Heightened dental anxiety can provoke physiological stress responses during dental visits. This impacts the salivary flow and composition. A significant association exists between higher levels of dental anxiety and a greater prevalence of dental caries in children.⁴ 

6. Pain associated with caries may trigger stress responses and lead to increased cortisol release. Chronic inflammation and infection linked to caries may also contribute to systemic inflammation and HPA axis dysregulation, further elevating cortisol levels. Research on early childhood caries (ECC) has explored its connection to salivary cortisol, which is a key hormone in stress response. Some studies found no significant difference between children with and without caries, while others noted higher cortisol levels in children with ECC even after dental treatment.⁴

Behavioural changes

1. Oral hygiene is intricately linked to mental health. Psychological disorders often lead to neglect of oral hygiene and buildup of plaque.⁵ Sometimes, people under stress brush too vigorously and damage the integrity of the tooth structures, which could make them more prone to tooth decay. Patients with elevated dental anxiety may avoid dental visits or delay them. This results in subsequent dental plaque buildup, a primary factor in the development of tooth decay. 

2. Psychological states significantly influence dietary choices in terms of type, consistency, and quantity of food consumed. Stress-related shifts towards cariogenic foods and beverages including carbohydrate-rich foods, soft foods, and sugary and acidic drinks will enhance plaque accumulation and cause oral dysbiosis (imbalance of oral microbial species). Increased consumption of high-fat foods under stress can elevate cortisol levels, leading to immunosuppression (reduction in the efficacy or functioning of the body’s immune system). This dietary pattern further contributes to the initiation and progression of tooth decay.^4,5 

3. Among stress-related habits, smoking stands out as particularly damaging to oral health. Bruxism, characterised by unconscious teeth grinding and jaw clenching, especially during sleep, often correlates with stress, anxiety, and mood disorders.⁵ This repetitive action of grinding the teeth may result in wearing down tooth enamel, lost fillings, and increased vulnerability to tooth decay.

Management of stress-related tooth decay

A multidisciplinary management with a general physician, dentist, and psychologist is required to identify subjects with chronic stress and to employ measures to decrease the impact of stress on oral health.⁵ Understanding how stress and salivary factors impact oral health is essential for creating preventive strategies and interventions focused on stress management to enhance a patient's oral health. 

Patients must receive comprehensive oral hygiene along with a prescription of high-fluoride toothpaste. Regular dental reviews and radiographic examinations are also essential for maintaining oral health. Since individuals with mental health conditions are more likely to smoke, have poor dietary habits, and consume excessive alcohol, it is essential to document thorough social histories and provide smoking, and alcohol cessation support and dietary advice as needed.⁷

It is crucial for dental care professionals to be at ease discussing mental health with their patients and to manage any related oral signs and symptoms effectively. They should also collaborate with other healthcare providers when needed. Dental practices should create supportive environments for patients, recognizing that their mental health is important.⁷ Additionally, employing strategies to lessen dental anxiety such as behaviour guidance techniques, and effective communication can alleviate anxiety, improve dental experiences, and reduce the risk of tooth decay.⁴ 

Summary

Stress can significantly contribute to tooth decay through various mechanisms, including physiological and behavioural changes. Stress can affect saliva production, composition and flow which leads to plaque buildup and compromises oral health. Stress often leads to unhealthy habits like poor diet and neglect of oral hygiene, which increase the risk of tooth decay. Understanding these links and addressing the effects of stress can help mitigate tooth decay and improve overall dental health.

By integrating psychological approaches and customised dental care, dental professionals can optimise oral health outcomes and improve the overall well-being of patients. Further research in this area will deepen our comprehension of the intricate relationship between stress and tooth decay, paving the way for better preventive and therapeutic approaches in dentistry.