Tooth decay is a widespread bacterial infection that damages tooth structure. If left unaddressed, it can lead to significant health problems.
The Decay’s Journey Through the Tooth
Tooth decay typically starts on the outermost layer of the tooth, the enamel. This hard, protective surface is eroded by acids produced by bacteria in plaque, often appearing as a small spot or hole. This initial stage, known as demineralization, can sometimes be reversed with proper oral hygiene and fluoride.
As decay progresses, it penetrates the enamel and reaches the softer, more porous dentin layer beneath. Dentin contains microscopic tubules leading to the tooth’s nerve. Once decay reaches this layer, sensitivity to hot, cold, or sweet foods and drinks often increases, and decay spreads more rapidly due to its less dense structure.
If decay continues, it moves deeper, approaching the pulp, the innermost part of the tooth containing nerves and blood vessels. At this stage, individuals may experience significant pain or discomfort.
When Infection Takes Hold
When decay reaches the pulp, bacteria invade this soft tissue, leading to inflammation known as pulpitis. This can cause intense pain. Pulpitis can be reversible if caught early, with symptoms like sharp, short-lived pain from cold stimuli. However, if inflammation persists and the pulp is damaged beyond repair, it becomes irreversible pulpitis, characterized by lingering pain, especially to heat, or spontaneous pain.
Left untreated, irreversible pulpitis can lead to pulp necrosis, the death of the pulp tissue. This occurs as the infection compromises the blood supply to the pulp. A necrotic pulp may initially cause pain, but sometimes the pain subsides as the nerve dies, leading to a false sense of resolution.
The infection from a necrotic pulp can then spread beyond the tooth’s root tip into the surrounding bone, forming a dental abscess. A periapical abscess is a pocket of pus at the root tip, which can cause severe pain, swelling, and sometimes a visible “pimple” on the gum.
Impact on Surrounding Oral Structures
An untreated dental abscess can severely impact surrounding oral structures. The infection and pus can erode the jawbone, weakening the support for the affected tooth and potentially adjacent teeth. This bone deterioration can lead to tooth loosening and, eventually, tooth loss.
While a cavity itself does not physically jump from one tooth to another, the bacteria that cause decay can spread throughout the mouth. Poor oral hygiene in the presence of a decayed tooth can allow these harmful bacteria to multiply and colonize neighboring teeth, increasing their risk of developing new cavities. Teeth that are closely packed are particularly susceptible to this bacterial transfer.
Chronic infection from a decayed tooth can also exacerbate existing gum inflammation, known as gingivitis, or contribute to the progression of periodontitis, a more severe form of gum disease. Periodontitis involves inflammation and infection of the tissues supporting the teeth, further contributing to bone loss and potential tooth mobility. Ultimately, severe decay, infection, and bone loss can necessitate tooth extraction, impacting chewing function, speech, and the alignment of remaining teeth.
Beyond the Mouth: Body-Wide Effects
An untreated dental infection is not confined to the oral cavity and can have systemic implications. Bacteria from a severe dental abscess can enter the bloodstream, a condition known as bacteremia. Once in the bloodstream, these bacteria can travel to distant parts of the body, potentially leading to infections in other organs.
Oral infections have been linked to an increased risk or exacerbation of various systemic health conditions. For instance, bacteria from the mouth can contribute to infective endocarditis, a serious infection of the heart’s inner lining, particularly in individuals with pre-existing heart conditions. Chronic oral infections can also make blood sugar control more challenging for individuals with diabetes.
There is also a potential connection between oral bacteria and respiratory infections, such as aspiration pneumonia, especially in vulnerable individuals. In pregnant individuals, periodontal disease has been associated with an increased risk of preterm birth and low birth weight. Chronic dental pain and infection can diminish overall well-being, affecting sleep, eating habits, and social interactions.