✓ Evidence Based

Cavities (Dental Caries/Tooth Decay): Stages, Causes, Treatment

Dental caries, or cavities, affects almost 2 billion people globally (1). In the United States, the CDC reports (2) that 90% of adults over the age of 20 have experienced at least one cavity, with one in four adults between the ages of 20 and 64 having been affected.

Caries are not exclusive to adults. Children can be afflicted by caries as well. In chldren ages 6 – 8, 52% have had caries in their primary teeth. In adolescents ages 12 – 19, 57% have had caries in their permanent teeth.

What are Cavities or Dental Caries?

Dental caries, commonly known as tooth decay or cavities, is a prevalent oral health health concern caused by a combination of factors. Dental caries progression can be influenced by bacteria, host factors (such as tooth enamel composition and saliva), and dietary sugars. This condition leads to demineralization of the tooth structure, primarily the enamel, followed by cavitation if left untreated (3).

Stages of Tooth Decay

Dental caries begin when bacteria in the mouth ferment dietary sugars. The bacteria produce acids, as a byproduct, that demineralize tooth enamel. The process is influenced by several factors. Factors like bacterial composition, salivary flow, fluoride exposure, and dietary habits can all influence the rate of caries progression. Streptococcus mutans, actinomyces, and lactobacilli are the primary bacteria associated with caries formation (4).
The progression of dental caries involves several stages (5).

  • Stage 1: Demineralization of the enamel.
  • Stage 2: Formation of subsurface lesion.
  • Stage 3: Further progression into deeper layers, possibly including the dental pulp.

Embracing an approach to limit caries formation can be beneficial to the patient. Dental caries is a serious public health concern, not only limited to the United States.


It is important to note that not all dental caries produce physical symptoms. Tooth decay may not be seen by the naked eye. Tooth decay can typically begin with white or brown spots on the teeth. Discoloration usually signals the initial stages of decay. If left untreated, these spots can progress into holes or cavities on the tooth surface. As decay advances, it can reach deeper layers of the teeth, potentially affecting the nerves and roots (6). The nerves and the rooth are commonly referred to as the dental pulp. A multitude of symptoms can occur with dental caries. Many depend on the depth and extent of the decay. Symptoms can include, but are not limited to those listed below.

  • Tooth discoloration
  • Sensitivity and pain
  • Increased sensitivity to sweet foods
  • Increased sensitivity to cold drinks

It is important to note not all dental caries present with symptoms. Examinations are essential in diagnosing caries and their extent. Prevention and early diagnosis can help prevent the onset of mentioned symptoms. Early detection can help ensure the decay does not spread to deeper layers of the tooth. If dental caries reach the deeper layers, including the pulp, this could indicate the need for additional procedures.


Dental caries can be attributed to a multitude of factors. While there is no one cause for dental caries, it often arises due to a combination of factors.

  • Diet: Total consumption of sugar and frequency of intake, contribute significantly to the onset of dental caries (7). The longer sugar is in contact with teeth the higher the risk of caries development. An increased consumption also can increase the risk of caries development.
  • Microflora: Streptococcus mutans, actinomyces, and lactobacilli play a key role in the caries process (4). These bacteria form a biofilm or plaque that sticks onto the enamel surface of teeth. Without removal of the plaque, the bacteria can feed off the sugars causing acidic byproducts that can lead to decay.
  • Tooth Susceptibility: Factors such as the form and arrangement of teeth contribute to susceptibility (8). The formation of enamel can affect susceptibility as well. Severe crowding can make it difficult to maintain proper hygiene and poor cleaning which could lead to an increase in decay as well.
  • Local risk factors: Salivary flow, oral hygiene, and tooth structure can influence caries development (9).
  • General risk factors: Age, sex, race, geographic location, and social class all play roles in dental caries prevalence (10).
  • Social-cultural environment: The community in which an individual lives can also impact the development of dental caries.


Treatment of dental caries involves various approaches depending on the severity of the condition. There are two categories of treatment options, non-surgical and surgical. Dental providers will provide insight into which option is most appropriate after the examination of the patient and their dental caries.

Non-surgical treatment:

  • Fluoride therapy: The application of fluoride can help remineralize enamel and halt the progression of early caries lesions (11). This remains helpful for very superficial decay.
  • Dietary modification: Reduction in sugar consumption to prevent further decay (11).
  • Oral hygiene education: Proper brushing and flossing techniques to help remove plaque and prevent decay (12). Proper brushing at home is essential along with dental cleaning provided by a professional.

Surgical treatment:

  • Dental restorations: Placement of fillings to restore teeth affected by the cavities.
  • Dental crowns: For extensive decay or weakened teeth, crowns may be placed to strengthen and protect the remaining tooth structure. Crowns are usually recommended if extensive tooth structure has been lost, or if the decay has reached the pulp and the tooth requires root canal therapy (13).
  • Root canal therapy: If decay reaches the pulp of the tooth, root canal treatment may be necessary to remove infected tissue and save the tooth (14). With root canal therapy, crowns may also be recommended in conjunction to provide the tooth with the best chance of survival.
  • Extraction: In cases of severe decay, where the tooth cannot be saved, extraction may be required and necessary to avoid systemic infections.

Preventive measures:

  • Dental sealants: Application of protective coatings to the chewing surfaces of molars to help prevent decay (15). Sealants are often recommended for pediatric populations, but adult populations can benefit from the preventive measures as well.
  • Regular dental check-ups: Routine visits to the dentist for examination and early detection of caries. Early caries detection can help prevent the spread and depth of the decay caries.

Treatment of dental caries involves a combination of preventive measures, non-surgical interventions, and surgical procedures tailored to the individual’s needs and the extent of decay. Early detection and prompt treatment are essential for preserving dental health and preventing complications associated with untreated caries.

Risk Factors

There are a variety of risk factors that can affect caries susceptibility. Some risk factors can be modifiable and some are non-modifiable.

  • Socioeconomic status: Lower socioeconomic status is associated with an increased risk of dental caries due to limited access to dental care, poor oral hygiene practices, and dietary habits (16).
  • Diet: High consumption of sugary foods and beverages, especially those with added sugars, increases the risk of dental caries. Frequent snacking and sipping sugary drinks throughout the day contribute to the development of caries (7). The longer sugar has contact with the teeth the higher the risk of caries development. Foods high in carbohydrates can affect dental caries as well. Carbohydrates break down into sugars that can be utilized by caries-forming bacteria.
  • Oral hygiene: Inadequate oral hygiene practices, such as infrequent brushing and flossing, lead to the accumulation of plaque and bacteria on the teeth, increasing the risk of caries (17).
  • Fluoride exposure: Insufficient exposure to fluoride, whether through lack of fluoridated drinking water, use of fluoride-free toothpaste, or lack of professional fluoride treatments, can predispose individuals to dental caries (18).
  • Microbial factors: Certain bacteria, particularly Streptococcus mutans and Lactobacillus species, play a significant role in the development of dental caries. Factors that promote the growth and colonization of these bacteria, such as frequent sugar consumption and poor oral hygiene, increase the risk of caries (4).
  • Salivary factors: Saliva maintains oral health by buffering acids, remineralizing enamel, and washing away food particles and bacteria. Salivary dysfunction or reduced saliva flow can increase the risk of dental caries (19).
  • Genetic factors: Genetic predisposition may influence an individual’s susceptibility to dental caries. Genetic variations related to enamel formation, saliva composition, and immune response may impact caries risk (20).
  • Age and gender: Children and older adults (especially geriatric populations) are at higher risk of dental caries. For children, enamel may be immature. In older populations, age-related changes in saliva flow and composition can lead to an increased risk of caries development. Additionally, females may be at increased risk due to hormonal changes during puberty, pregnancy, and menopause (9).

Risk factors interact with each other and contribute to the multifactorial nature of dental caries. Addressing these risk factors through preventive measures and targeted interventions is essential for reducing the incidence of dental caries and promoting good oral health.

Diagnosing dental caries

Dental caries remains a prevalent global issue, but advancements in diagnostic testing have enabled earlier detection and intervention. A combination of diagnostic tests, including visual-tactile examination, radiographs, caries detection dyes, and newer tools like laser fluorescence detection devices and light-induced fluorescence, are used for accurate diagnosis.. These tests provide qualitative and quantitative information about carious lesions, aiding in treatment planning and monitoring. While radiographs offer a qualitative diagnosis, newer tools like laser fluorescence detection devices and light-induced fluorescence provide more precise data, including lesion location, extension, bacterial activity, and remineralization/demineralization processes. Dental caries will be examined and diagnosed by a dental professional. This comprehensive approach ensures timely and effective management of dental caries (21).


Dental caries can be prevented with several techniques. A combination of these techniques can help reduce caries risk and chance of caries formation (22).

  • Removal of plaque: Regular removal of dental plaque through effective oral hygiene practices is essential to prevent caries.
  • Reduction in sugar consumption: Given the extensive evidence linking dietary sugars to dental caries, reducing sugar intake is crucial in preventing caries formation.
  • Coating the tooth surface: Applying coatings to form a barrier between plaque and enamel can help protect against caries development in the form of dental sealants.

With proper dental hygiene, diet modification, and regular dental visits, dental caries can be prevented.


Dental caries, also known as cavities, are prevalent in the United States, affecting almost all individuals, with 90% of adults over 20 and 1 in 4 adults between 20-64 having at least one cavity. Children are also susceptible, with 52% of 6-8 year-olds and 57% of adolescents ages 12-19 having experienced caries. The condition is caused by a combination of factors including bacteria, dietary sugars, and host factors leading to demineralization of tooth enamel. Preventive measures such as plaque removal, reducing sugar consumption, and dental sealants can help prevent caries formation, emphasizing the importance of proper dental hygiene and regular check-ups.