Saliva plays a diverse role in maintaining oral health. It acts as a natural cleanser, helping to wash away food particles and debris, and contains components that protect against harmful bacteria. A balanced pH level is important for these protective functions, as shifts can compromise the oral environment. When this balance shifts towards increased acidity, it can initiate issues that affect the teeth and gums.
Understanding Saliva Acidity
Saliva’s pH measures its acidity or alkalinity, ranging from 0 (most acidic) to 14 (most alkaline), with 7 being neutral. A healthy oral cavity maintains a salivary pH between 6.2 and 7.6, averaging 6.7, indicating it is slightly acidic to neutral. When saliva’s pH drops below 7.0, it becomes acidic, posing a risk to oral structures. Specifically, a pH below 5.5 can initiate demineralization, where tooth enamel begins to lose its mineral content. This softening makes teeth more vulnerable to damage.
Common Causes of Imbalance
Dietary choices, such as consuming sugary or acidic foods and beverages like soft drinks, citrus fruits, and processed snacks, contribute significantly to acidic saliva. Bacteria in the mouth metabolize carbohydrates from these foods, releasing acids that lower the saliva’s pH. Frequent snacking throughout the day can also prevent the mouth’s pH from recovering, leading to prolonged acidic conditions.
Certain medical conditions can cause acidic saliva. Gastroesophageal reflux disease (GERD), for example, allows stomach acids to reflux into the mouth, directly lowers salivary pH. Conditions that reduce salivary flow, such as Sjögren’s syndrome or diabetes, can result in more concentrated, acidic saliva, as the buffering capacity is diminished.
Some medications, including antihistamines and antidepressants, can cause dry mouth, leading to increased acidity. Lifestyle habits, such as tobacco use and excessive alcohol consumption, are linked to lower salivary pH. Dehydration can concentrate saliva, making it more acidic.
Impact on Oral Health
Prolonged exposure to acidic saliva can negatively impact oral health. One direct effect is dental erosion, the wearing away of tooth enamel from acid exposure. This erosion can make teeth appear yellowish as the underlying dentin becomes more exposed. The softened enamel also increases the risk of dental caries, commonly known as cavities, as bacteria can more easily penetrate the tooth structure.
Beyond enamel erosion and cavities, acidic saliva can increase tooth sensitivity, particularly to hot, cold, or sweet stimuli. The acidic environment also favors the growth of harmful bacteria, contributing to gum inflammation, or gingivitis. An altered oral microbiome resulting from sustained acidity can also contribute to halitosis, or bad breath.
Diagnosis and Management
Identifying acidic saliva often begins with a dental examination, where a professional looks for signs of enamel erosion or increased decay. Saliva pH testing can be performed in a dental office or at home using pH strips, which indicate acidity by changing color. For accurate results, it is recommended to avoid eating or drinking for at least two hours before testing.
Managing acidic saliva involves lifestyle adjustments and professional interventions. Dietary modifications often include reducing intake of acidic and sugary foods and beverages. Rinsing the mouth with water after meals helps wash away acidic residues and restore pH balance. Chewing sugar-free gum, especially those containing xylitol, stimulates saliva flow, naturally buffering acids and helping remineralize enamel. Ensuring adequate hydration by drinking plenty of water also benefits maintaining saliva production and a neutral pH.
Addressing any underlying medical conditions, such as GERD, is important for long-term management. In some cases, fluoride toothpastes and rinses may be recommended to strengthen enamel and protect against acid damage.