The pH of saliva plays an important role in people’s oral health, as it is a factor in the protection against tooth decay. 

Leonor Martin-Pero Muñoz. Dental hygienist. Commission for Oral Health and Prevention of the Professional Association of Dental Hygienists of Madrid. 

Saliva performs a series of roles that can be classified into three main functions: digestive, protective and disease-related. The latter category stands out as what is known as saliva’s "buffer capacity," which helps to maintain a balanced pH in the mouth. 

The pH of saliva has a considerable impact on oral health, as it is a factor in the protection against tooth decay. It should range between 6.5 and 7 to maintain the balance for good oral health.  

The mouth is an ecosystem that, like other parts of the body, requires a balanced pH. When sugary and acidic foods are consumed very frequently throughout the day, salivary pH becomes unbalanced because bacteria metabolise sugars and produce acids, which increases the risk of decay. 

A low buffer capacity of saliva is indicative of high caries risk, so it is important to check this situation in patients. To do so, pH test strips can be used to assess the buffer capacity, i.e. the ability to buffer pH fluctuations. It is a simple, cheap method that provides information on the protective capacity of the patient's saliva against tooth decay. This information is useful in order to enhance protective factors against caries, as it gives us an idea of how the patient can recover their saliva’s pH balance. 

WHAT IS pH? 

It is a value that indicates the degree of acidity or alkalinity of a substance. 

It is applied on a scale of 0 to 14, with zero being the most acidic, and 14 the most alkaline.