What Is Tooth Decay?
Tooth decay begins when bacteria in dental plaque produce acids after feeding on sugars from food and drink. These acids dissolve minerals from the outer enamel layer of the tooth in a process known as demineralisation. Saliva naturally helps to repair some of this damage by returning minerals to the enamel, but when acid attacks occur frequently, the repair process cannot keep pace and the enamel gradually weakens.
If left unchecked, decay progresses through the enamel into the softer dentine beneath. Dentine is less resistant to acid and decay can advance more quickly once this layer is reached. Should the decay continue further, it may eventually reach the dental pulp — the innermost part of the tooth containing nerves and blood vessels — which can lead to infection, inflammation, and significant pain.
Untreated decay can result in abscess formation, where a pocket of pus develops around the root of the tooth. At this stage, more extensive treatment is typically required, and in some cases the tooth may not be salvageable. Early detection through regular dental assessments allows decay to be managed at a simpler, more conservative stage.
Common Causes of Tooth Decay
Several factors contribute to the development of tooth decay. Risk varies between individuals, and more than one factor is often involved. The following are among the most common contributors:
Frequent Sugary or Acidic Foods and Drinks
Bacteria in dental plaque feed on sugars and produce acids as a by-product. Frequent consumption of sugary or acidic foods and drinks increases the duration of acid exposure on the tooth surface.
Poor Oral Hygiene
When plaque is not removed effectively through regular brushing and flossing, bacteria accumulate on the tooth surface and continue to produce acids that weaken the enamel over time.
Dry Mouth
Saliva plays a protective role by neutralising acids and helping to remineralise enamel. Reduced saliva flow — whether due to medication, medical conditions, or other factors — can increase decay risk.
Deep Grooves in Teeth
The natural grooves and fissures on the biting surfaces of back teeth can harbour plaque and bacteria that are difficult to reach with a toothbrush, making these areas more susceptible to decay.
Irregular Dental Check-ups
Without regular professional assessment, early signs of decay may go undetected. Routine check-ups allow your dentist to identify areas of concern before they progress to more advanced stages.
Early Signs and Symptoms
In its earliest stages, tooth decay may produce subtle changes that are easy to overlook. Recognising these early indicators can prompt timely assessment:
White or Brown Spots on Teeth
One of the earliest visible signs of decay is a chalky white or light brown patch on the enamel surface, indicating early mineral loss.
Sensitivity to Sweet Foods
A mild twinge when consuming sugary foods or drinks can indicate that enamel has begun to weaken, allowing stimuli to reach the dentine beneath.
Mild Discomfort
Occasional, low-level discomfort around a tooth — particularly when eating — may be an early indicator, though it can be easy to overlook.
No Symptoms at All
In many cases, early decay produces no pain or visible change. This is why regular dental check-ups are important for detection before symptoms develop.
Symptoms of Advanced Decay
As decay progresses deeper into the tooth, symptoms typically become more noticeable and may include:
Persistent Toothache
Continuous or recurring pain in or around a tooth that may be dull, throbbing, or sharp — often indicating that decay has reached deeper layers of the tooth.
Pain When Biting
Discomfort when chewing or biting down can occur when decay has weakened the tooth structure or when infection is developing at the root.
Sensitivity to Hot or Cold
Prolonged sensitivity to temperature — particularly pain that lingers after the trigger is removed — may indicate that decay has reached or is close to the pulp.
Visible Holes in Teeth
A cavity that is visible to the eye or can be felt with the tongue suggests that decay has progressed through the enamel and into the underlying tooth structure.
Swelling or Abscess
Swelling of the gum, face, or jaw near a decayed tooth may indicate that infection has developed — a sign that professional assessment should not be delayed.
The presence of advanced symptoms does not necessarily mean the tooth cannot be saved. Professional assessment will determine the most appropriate course of action.
Why Professional Assessment Is Important
Tooth decay is not always visible or symptomatic, particularly in its early stages. Decay can develop between teeth, beneath existing restorations, or in areas that are difficult to see without professional instruments. This is why regular dental check-ups play such an important role in maintaining oral health.
During an assessment, your dentist may use clinical examination, dental imaging, and other diagnostic methods to identify areas of concern. Early detection is significant because it often allows decay to be managed with simpler, more conservative treatments — preserving more of the natural tooth structure.
Without timely assessment, decay that begins as a small area of enamel weakness can progress to a stage where more extensive intervention is needed. In some cases, untreated decay can lead to dental abscess, which may require root canal treatment or extraction. Professional assessment helps to prevent this progression wherever possible.
Professional Treatment Options for Tooth Decay
Treatment for tooth decay depends on the stage at which it is identified. Your dentist will recommend the most appropriate approach based on the clinical findings. Options may include:
Preventive Advice and Monitoring
For very early enamel changes, your dentist may recommend improved oral hygiene, dietary modifications, and fluoride application, with regular monitoring to assess whether the area stabilises.
Dental Fillings
When a cavity has formed, a filling removes the decayed material and restores the tooth with a durable material. This is the most common treatment for moderate decay.
Root Canal Treatment
If decay has reached the pulp — the innermost part of the tooth containing nerves and blood vessels — root canal treatment may be needed to remove the infected tissue and preserve the tooth.
Dental Crowns
For teeth with extensive decay or structural damage, a crown provides a protective cap that restores the tooth's shape, strength, and function.
Tooth Extraction
In severe cases where the tooth cannot be predictably restored, extraction may be the most appropriate option. Your dentist will discuss replacement options where relevant.
Treatment outcomes depend on individual circumstances, including the extent of decay and the overall condition of the tooth. Your dentist will explain what can reasonably be expected.
Professional Care for Tooth Decay
Professional dental assessment allows decay to be identified and treated at an appropriate stage to preserve long-term tooth health. Whether your concern is a new symptom or a routine check, your dentist can evaluate the situation and discuss the best course of action.
Depending on the findings, your dentist may recommend general dental treatment including fillings, root canal treatment if the pulp is affected, a protective dental crown for extensive damage, or an emergency dental assessment if symptoms are severe.
Assessment and treatment for tooth decay are available at our London clinics. You can attend our South Kensington dental clinic or our City of London clinic near St Paul's for a professional dental review.
Can Tooth Decay Be Reversed?
In the very earliest stages, when decay is limited to initial mineral loss from the enamel surface, it may be possible for the process to stabilise or partially reverse. This requires consistent oral hygiene, reduced sugar exposure, and adequate fluoride — which supports the natural remineralisation process.
However, once a cavity has formed — meaning the tooth structure has physically broken down — the damage cannot repair itself. At this stage, professional treatment is needed to remove the decayed material and restore the tooth.
Regular dental monitoring is valuable because it allows your dentist to identify early changes and advise on whether preventive measures are sufficient, or whether active treatment is appropriate. The earlier decay is identified, the more conservative the management can be.
Preventing Tooth Decay
While individual susceptibility to decay varies, the following daily habits and professional care can significantly reduce your risk:
- Brush teeth twice daily with a fluoride toothpaste using a soft-bristled toothbrush
- Clean between teeth daily with floss or interdental brushes
- Limit the frequency of sugary and acidic food and drink consumption
- Drink water regularly throughout the day to support saliva flow
- Attend routine dental check-ups so early changes can be identified and monitored
- Ask your dentist about professional cleaning if plaque build-up is a concern
