Causes and Risk Factors
Tooth decay and cavities are largely caused by acid secreted by bacteria. This acid erodes the hard enamel on the tooth surface, eventually exposing the vulnerable interior of the tooth (Mayo Clinic 2014a). Dysbiosis is thought to be an important cause of periodontal disease. Dysbiosis occurs when disease-causing bacteria that promote inflammation and break down teeth and gums (and in severe cases, even bone) overcome the normal balance of bacteria in the mouth and in the biofilm (Hajishengallis 2015; Mayo Clinic 2014b; Zaura 2014). Examples of bacteria that can contribute to periodontal disease include Streptococcus sobrinus (S. sobrinus), S. mutans, and some Actinomyces species (Kalesinskas 2014; Fazili 2015; Sutter 1984).
Caries (cavities). Risk factors for cavities in adults include high dietary sugar, poor dental hygiene, dry mouth, worn fillings, and poorly fitting dental devices. In addition, medical conditions that increase oral exposure to digestive acid, such as gastroesophageal reflux disease and bulimia nervosa, lead to enamel erosion, tooth decay, and cavities. Deeply grooved teeth are more prone to cavities, as are tooth surfaces that are hard to access for cleaning (Mayo Clinic 2014a).
Periodontal disease. Periodontal disease risk is influenced by the composition of the oral microbial community, which can increase or decrease risk. There are several other behavioral, genetic, and environmental risk factors for periodontal disease (Kawar 2011):
- Smoking tobacco, and possibly marijuana (Thomson 2008; UMMC 2013; Gulati 2013)
- Older age (especially 65 or older) (Hajishengallis 2014; Kawar 2011)
- Female gender, especially during hormonal changes such as puberty and pregnancy (Gulati 2013; UMMC 2013)
- Family history (UMMC 2013)
- Obesity and metabolic syndrome (Bharti 2009; Kawar 2011)
- Other systemic diseases, including autoimmune diseases and immune-deficiency diseases like leukemia and AIDS (UMMC 2013)
- Dental problems related to wisdom teeth or poorly fitting crowns or fillings (UMMC 2013)
- Stress, anxiety, and depression (UMMC 2013; Oppermann 2012)