Dental Caries

What Is Dental Caries?

Dental caries — more commonly referred to as tooth decay — is an infectious, transmissible condition that progressively damages the hard structure of your teeth. It develops when bacteria living in the mouth convert sugars from food and drink into acids, which then attack the tooth’s outer layers. Without treatment, dental caries can escalate into more serious problems and significantly compromise your oral health.

As tooth decay progresses unchecked, it can give rise to a range of complications including dental pain, infection, tooth sensitivity, and in advanced cases, complete tooth loss.

Dental cavities are the direct result of untreated decay. They appear as small or large openings — holes — that form within the tooth structure once the enamel has been sufficiently eroded.
A tooth abscess is a painful condition that can develop from an untreated cavity. It involves a localised collection of pus forming within or around the tooth or gum tissue as a result of bacterial infection.

When a tooth is in trouble, your dentist will always explore every option available to save it with the most appropriate treatment possible.

Dental caries ranks among the most widespread oral health conditions globally and can affect both primary (baby) teeth and permanent adult teeth. When it occurs in very young children, it is commonly called early childhood caries or baby bottle tooth decay. In recent years, wider adoption of good oral hygiene practices and the introduction of fluoride into public water supplies have contributed to a reduction in the prevalence of this condition.

What Causes Dental Caries?

How Tooth Decay Develops

Dental plaque is a soft, transparent, sticky film made up of bacteria that continuously forms on tooth surfaces and along or beneath the gumline. It builds up when the bacteria naturally present in the mouth interact with carbohydrate-rich foods — particularly those high in starch or sugar.

Plaque must be disrupted and removed through regular brushing, as the bacteria it harbours are highly damaging to tooth structure. When plaque bacteria come into contact with sugars from food and drinks, they metabolise these sugars and release acids as a by-product. These acids strip minerals from the tooth enamel, weaken its structure, and over time create the conditions in which cavities can develop.

What Are the Risk Factors for Dental Caries?

Who Is Most at Risk of Tooth Decay?

Dental caries can affect anyone at any age, but certain behaviours and circumstances make some individuals more vulnerable than others. In general, those who consume high quantities of sugary or starchy food and drinks, neglect regular oral hygiene, or fail to remove harmful bacteria from the mouth face the greatest risk.

Common risk factors include:

High Sugar Consumption

A diet rich in sweets, processed foods, and sugary beverages — including soft drinks, juices, and sports drinks — places teeth under sustained acid attack. When these sugars combine with plaque bacteria on the tooth surface, acids are produced that gradually dissolve the enamel and break down the underlying tooth structure, paving the way for decay.

Poor Oral Hygiene Habits

Failing to clean teeth adequately is one of the leading contributors to tooth decay. Brushing with fluoride toothpaste for two full minutes, twice daily, is widely recommended by dental health authorities as the baseline for preventing cavities. Consistent flossing is equally important to remove food debris and plaque from between teeth — areas that a toothbrush cannot effectively reach.

Dry Mouth

Saliva plays a critical role in protecting teeth. It neutralises acids produced by bacteria, washes away food particles and sugar, and helps restore minerals to enamel that has been mildly damaged. When saliva production is reduced, this natural defence mechanism is compromised and the risk of decay rises considerably.

Dry mouth can be triggered by a range of factors including certain medications, underlying medical conditions, insufficient water intake, and excessive consumption of caffeine-containing drinks such as coffee, tea, and cola. Some chemotherapy agents can also interfere with normal saliva flow.

Position of the Teeth

The rear teeth — molars and premolars — are disproportionately affected by tooth decay. Their complex surfaces, featuring deep grooves, fissures, and pits, make thorough cleaning more difficult, allowing plaque to accumulate and persist in hard-to-reach areas.

Insufficient Fluoride Exposure

Fluoride is a naturally occurring mineral with well-established cavity-fighting properties. It strengthens tooth enamel, making it more resistant to acid attack, and can help arrest or reverse decay in its earliest stages.

Regular exposure to fluoride — through fluoridated toothpaste, professional dental treatments, or fluoridated tap water — offers meaningful protection against dental caries. If you primarily drink bottled water or your local water supply is not fluoridated, speak to your dentist about the most appropriate fluoride supplementation for your needs.

Age

Dental caries is particularly prevalent across three age groups: young children, teenagers, and older adults.

Young children who are put to bed with a bottle containing sweetened milk, juice, or formula are at heightened risk of developing early childhood caries, as their teeth are bathed in sugar for prolonged periods overnight.
Teenagers who frequently snack or sip on sugary drinks throughout the day expose their teeth to repeated acid attacks, raising their risk of decay significantly.
Older adults are more susceptible to tooth decay partly due to the natural wear of tooth surfaces over time, and partly because many medications commonly used in this age group can reduce saliva production and contribute to a dry mouth environment.

Gastro-Oesophageal Reflux Disease (GORD)

GORD is a digestive condition in which stomach acid repeatedly flows back up through the oesophagus and into the mouth. This highly acidic content can erode tooth enamel, exposing the softer dentine layer beneath and substantially increasing vulnerability to dental caries.

How Can You Prevent Tooth Decay?

Strategies for Preventing Dental Caries

Keep your mouth adequately hydrated.

Maintaining good saliva flow is one of the body’s natural defences against tooth decay. Saliva dilutes and washes away sugars from the tooth surface before they can be converted into damaging acids, and can even assist in remineralising enamel in the very early stages of decay. Drinking water regularly throughout the day supports healthy saliva production.

Maintain a thorough oral hygiene routine.

Brush your teeth twice daily using a fluoride toothpaste and correct technique — ensuring you clean the inner, outer, and biting surfaces of every tooth. Do not neglect the gumline. Complement brushing with daily flossing to clear away plaque and food debris from between the teeth where brushing alone cannot reach.

Schedule regular dental visits.

Attending check-ups every six months allows your dentist to identify any early signs of decay before they develop into more serious issues. Treatment is always more straightforward — and less costly — when problems are caught at an early stage. Your dentist can also offer professional fluoride treatments to help strengthen enamel and treat superficial decay before it progresses.

Choose tap water over bottled water where possible.

Most public tap water supplies contain added fluoride, which plays an active role in protecting teeth from decay. Choosing tap water as your primary beverage is a simple and cost-effective way to benefit from this daily protection. If your local supply is not fluoridated, ask your dentist about suitable alternatives.

Consider dental sealants.

Dental sealants are thin protective coatings painted onto the chewing surfaces of the back teeth to shield the grooves and pits where decay most commonly begins. They are particularly recommended for children and adolescents, and have been shown to significantly reduce the likelihood of cavities forming on treated teeth.

Reduce your intake of sugary and sticky foods.

Limiting how often you consume sweet snacks — especially between meals — reduces the frequency of acid attacks on your teeth throughout the day. Sticky sugary foods are especially harmful as they cling to the tooth surface for longer periods, prolonging the exposure and increasing the damage.

What Are the Symptoms of Dental Caries?

Signs of Tooth Decay to Watch For

In its earliest stages, tooth decay may produce no noticeable symptoms at all — which is one of the reasons regular dental check-ups are so important. As the condition advances, however, a range of warning signs may begin to appear:

Toothache or spontaneous tooth pain
Discomfort or pain when biting down on food
Increased sensitivity to hot, cold, or sweet stimuli
Visible holes or indentations in the affected tooth
Discolouration on the tooth surface — which may appear white, grey, brown, or black depending on the stage of decay

If you notice any of these symptoms, arrange an appointment with your dentist promptly. Early intervention can prevent the decay from progressing further and reduce the complexity of treatment required.

Dental Caries Treatment

Treatment Options for Tooth Decay

Regular dental visits — ideally twice a year — are the most effective way to prevent decay from developing or to catch it before it worsens. The treatment your dentist recommends will depend on how advanced the decay has become at the time of diagnosis.

Fluoride Treatments

At its earliest stage, tooth decay can sometimes be halted or reversed with professional fluoride therapy. Applied directly to the tooth surface as a gel, foam, or varnish, concentrated fluoride helps to remineralise weakened enamel and strengthen the tooth against further acid attack.

Dental Fillings

Once decay has progressed far enough to create a cavity — a hole in the tooth — the affected material must be removed and the space restored with a filling. Fillings can be made from several materials depending on the location of the tooth and the extent of damage.

FYI: Filling materials include dental amalgam, which is commonly used for back teeth, and tooth-coloured composite resin, which blends seamlessly with natural teeth. Gold and ceramic options are also available but carry a higher cost. In young children, tooth-coloured restorations are generally the preferred choice. For larger cavities in children, a stainless steel crown may be recommended by the dentist to provide a more durable and long-lasting result.

Root Canal Treatment

When decay penetrates deep enough to reach the inner pulp of the tooth — the soft tissue containing nerves and blood vessels — infection becomes a serious risk. In these cases, root canal treatment is used to remove the damaged pulp, clean and disinfect the canal space, and seal it. A dental crown is typically placed over the treated tooth afterwards to restore its strength and appearance. Anaesthesia is used throughout the procedure to ensure patient comfort.

FYI: The dental pulp is the innermost layer of the tooth, housing the nerves and blood supply that kept the tooth vital during its development.

Tooth Extraction

When a tooth has been so severely compromised by decay that it cannot be reliably restored, removal is the final option. This prevents further infection from spreading and allows for future tooth replacement options to be explored.