Cavities are damages to the tooth. You get this condition from the tooth decay. Tooth decay can affect the inner layer (called dentin) and the outer coating of a tooth (called enamel). When foods which have carbohydrates like candy, cake, fruit, soda, milk, cereal or bread stay on your teeth, then the bacteria in your mouth can turn them into acids. Your saliva, food debris, acid and bacteria combine to form the plaque which clings to the teeth. Acids which are in plaque dissolve the enamel which is creating holes called cavities. There are many people who think that only children get cavities but we know that there are many changes in our mouth which are happening as we are getting older, so they can also lead to tooth cavities. We know that as we are getting older, our gums pull away from the teeth. Also they can pull away because of the gum disease. This is exposing the roots of your teeth to the plaque. Also if you eat a lot of high – carb foods or a lot of sugary foods, then you have increased chances of getting cavities. [1,2] Also there are some cases when older adults get decay when they have edges of fillings. Seniors in many cases have a lot of dental work because when they were kinds, they did not have fluoride or good oral care . As years are passing by, these fillings can weaken our teeth and break them. Bacteria accumulate in the gaps and this is causing decay. Dentist can find if you have tooth cavities during a regular dental check up. Your doctor will look your teeth, look for soft spots or he can use X – rays between your teeth. If you have a cavity for a while, then you can get a toothache, especially after you drink or eat something cold, hot or sweet. Also there are some cases when you can see holes or pits in your teeth.
Symptoms on cavities formations
The signs and symptoms of cavities can vary which depends on their location and extent. When the cavity is beginning, then you may not have any symptoms at all. But as the decay gets larger, then it can cause signs and symptoms such as
- Pain when you bite
- Brown, black or white staining on any surface of a tooth
- Visible holes or pits in your teeth
- Mild to sharp pain when eating or drinking something sweet, hot or cold
- Tooth sensitivity
- Toothache, spontaneous pain or pain that occurs without any apparent cause
Causes of cavities formation
It is known fact that tooth cavities are caused by tooth decay, a process which happen over time. Here is how the tooth decay develops:
- Plaque forms: The clear and sticky film that coats your teeth is dental plaque. It is caused by eating a lot of starches and sugars and not cleaning your teeth well. When starches and sugars are not cleaned off your teeth, then the bacteria quickly begin feeding on your teeth and it forms plaque. Plaque which stays on your teeth can harden above or under your gum line into the tartar (also called calculus). This is making the plaque more difficult to remove and it creates a shield for the bacteria. 
- Plaque attacks: Acids which are in plaque remove minerals from your enamel. The first stage of cavities is next: The previous mentioned erosion is causing tiny holes or openings in your enamel. When the areas of the enamel are worn away, then the bacteria and acid can reach the dentin, which is the next layer of your teeth. Dentin is softer than the enamel and it is less resistant to acid. This layer has tiny tubes which are directly communicating with the nerve of your tooth which is causing sensitivity.
- The destruction is continuing: As your tooth decay develops, then the acid and bacteria continue their march through your teeth and this is moving to the inner material – pulp, which has nerves and blood vessels. This pulp becomes and irritated and swollen from the bacteria. You should know that there is no place for the swelling to expand inside your tooth, your nerve becomes pressed which is causing pain. Also this discomfort can extend outside the tooth root to the bone. 
Risk factors: Here are some risk factors for cavities:
- Eating disorders 
- Worn fillings or dental devices 
- Dry mouth
- Younger or older age 
- Not getting enough fluoride
- Inadequate brushing 
- Bedtime infant feeding
- Frequent snacking or sipping
- Certain foods and drinks 
- Tooth location
 Heng C. Tooth decay is the most prevalent disease. Federal Practitioner. 2016;33(10):31–3.
 Centers for Disease Control and Prevention. Periodontal disease. Retrieved from www.cdc.gov/oralhealth/conditions/periodontal-disease.html
 Griffin SO, Jones JA, Brunson D, et al. Burden of oral disease among older adults and implications for public health priorities. American Journal of Public Health. 2012;102(3):411–8.
 Lingstrom P, van Houte J, Kashket S. Food starches and dental caries. Critical Reviews in Oral Biology & Medicine. 2000;11(3):366-80.
 University of Pennsylvania. Cavity-causing bacteria assemble an army of protective microbes on human teeth. Science Daily. 2020. Retrieved from sciencedaily.com/releases/2020/05/200518154937
 NHS. Fillings can ‘do more harm than good’, researchers warn. 2015. Retrieved from www.nhs.uk/news/medical-practice/fillings-can-do-more-harm-than-good-researchers-warn/