What Causes Cavities and Tooth Decay? A Complete Guide for All

Tooth decay and cavities are one of the most common chronic issues faced globally. Everyone will go through enamel erosion at some point in their lives whether they are a toddler or elderly person. If left untreated cavities can cause extreme pain, further infection and expensive dental treatment leading to tooth loss.

Understanding the causes of tooth decay will help keep your teeth in great condition and ensure you have a beautiful smile for life. Within this health guide we will explain all you need to know about cavities.

1. What Are Cavities and Tooth Decay?

Tooth decay is an ongoing process which will cause damage to the hard outer layers of your teeth. Dentists refer to this as dental caries.

Cavities are holes or pits within the hard surfaces of your teeth which have caused permanent damage.

• Enamel Erosion – Tooth decay starts on the outermost layer of your teeth known as enamel. Enamel is the hardest part of the human body.

• Dentin Erosion – If the enamel isn’t treated then decay will travel through to the dentin. This is the second layer below enamel and is much softer. It contains micro-tubes which travel right to the nerve of your tooth.

• Infection – In later stages the decay will reach the center of your teeth known as the pulp. This contains your living nerves and blood vessels. This will cause extreme pain and can cause dental abscesses.

2. How Are Cavities Formed?

Cavities aren’t formed overnight. They are actually caused by constant chemical reactions.

• Plaque Build Up – Naturally there will be small amounts of bacteria in your mouth. As you eat and drink these will mix with food particles and saliva creating a sticky clear substance known as plaque.

• Bacteria Eating Sugars – These bacteria within the plaque love to eat refined sugars. As they eat they create a corrosive acid.

• Acid Eats Enamel – The acid inside the plaque will eat away at the essential minerals such as calcium and phosphate within your enamel. This is known as demineralisation.

• Cavity – Over time your enamel will break down and cause cavities.

3. What Are the Main Causes of Tooth Decay?

Tooth decay can be caused by various reasons.

• Harmful Bacteria – Certain strains of bacteria such as Streptococcus mutans will cause cavities. These bacteria will stick to your teeth and create lots of lactic acid.

• Too Much Sugary Foods – Eating too many sweet snacks, sweets, cookies, fizzy and sweetened drinks will cause cavity causing bacteria to have endless food.

• Too Much Snacking – Constant sipping on sugary drinks and snacking throughout the day will mean your enamel is constantly attacked by the acid.

• Not Brushing – If you don’t brush your teeth daily then a thick layer of plaque will build up and turn into calculus. This creates the perfect environment for destructive bacteria.

4. Which Foods and Drinks Cause Enamel Erosion?

Certain foods can cause cavities to form quickly.

• Sticky Sweets and Dried Fruits – Sticky sweets, caramels, raisins and gummies will get stuck in the grooves of your molars. These will sit on your teeth for hours providing food for the bacteria.

• Sweet Fizzy Drinks – All fizzy drinks, sports drinks and energy drinks contain high amounts of refined sugars and are very acidic.

• Refined Starchy Foods – Crisps, white bread, crackers and pretzels will break down quickly to simple sugars. They are also very soft and will get stuck between your tight teeth.

• Acidic Citrus Fruits – Lemons, limes, oranges and grapefruit are high in useful vitamins but contain high levels of natural acids causing your teeth to temporarily weaken.

5. Which Medical Conditions Cause Cavities?

Medical conditions can increase the chance of getting cavities.

• Dry Mouth – Saliva helps to clean your teeth by removing food particles, neutralizing harmful acids and replacing minerals in your enamel. Medical conditions, aging and regularly taking medication can cause you to have less saliva causing cavities.

• GERD – Chronic acid reflux will cause your harsh stomach acids to wash into your mouth causing enamel erosion.

• Eating Disorders – If you suffer from eating disorders such as bulimia then your teeth will be constantly exposed to stomach acids causing severe enamel erosion and fast growing cavities.

• Radiation Therapy – If you’re receiving cancer treatment to your head/neck region then this can damage your salivary glands meaning you produce less saliva.

6. Why Does a Dry Mouth Cause Issues?

Saliva is your main defense. Here’s why:

• Neutralize Acids – Contains natural bicarbonate to neutralize any acids after eating.

• Minerals – Healthy saliva contains calcium and phosphate ions which will help repair your enamel.

• Washes Away Debris – Constant saliva flow will help wash away food particles, sticky sugars and loose bacteria.

• Antibacterial – Contains special proteins to help slow bacteria growth.

7. What Are the Signs You Have Cavities?

If you experience any of the following signs your dentist can help treat the small amount of decay.

• Pain In Teeth – If you’re experiencing sharp pain in your teeth or sudden pains with no cause then you may have decay.

• Hot and Cold Sensitivity – If you experience sharp pain when drinking hot soups, teas, ice creams or cold water then you may have decayed into your dentin.

• Sweet Sensitivity – If you experience dull or sharp pains when eating sweets then you have damaged enamel.

• Dark Patches/Pits – If you notice dark brown patches, black patches, white chalky patches or pits then you have damaged enamel.

• Pain When Chewing – If you experience pain when chewing then your tooth may have weakened due to decay or you may have inflammation at the tip of your root.

8. How Will Dentists Diagnose Cavities?

Dentists will use specialist tools to detect cavities at an early stage.

• Clinical Examination – Your dentist will use specialist mirrors, bright lights and loupe magnifiers to look for any soft spots, discoloration or pits on the outside of your teeth.

• Digital X-Rays – Low radiation digital x-rays can help detect cavities between your teeth.

• Intraoral Camera – High definition cameras will take clear images of problem areas showing exactly where your enamel has broken down.

• Laser Detection – Special laser detection will show how much light is reflecting off your teeth. This will show any hidden decay in the grooves of your molars.

9. What Are the Treatments for Tooth Decay?

Treatment will depend on how deep the decay is.

• Remineralisation – If there is only a small amount of decay (white spot lesion) then your dentist can treat this without drilling. They will apply high concentration fluoride varnishes.

• Fillings – If there is a cavity in your enamel then your dentist will clean out the decay and fill it with tooth colored filling.

• Crowns – If there is a lot of decay or damage then your dentist will reshape your tooth and fit a strong crown made from porcelain or ceramic.

• Root Canal – If your decay has reached your nerve then an endodontist will clean out the infected pulp. They will clean out your root canals and fit a crown.

• Extraction – If your tooth has been completely destroyed by the decay then your dentist will need to extract it.

10. How Can You Prevent Tooth Decay?

To prevent tooth decay you should follow good personal hygiene and take note of your dentist’s advice.

• Brush Twice A Day – Brush your teeth for 2 minutes twice a day using a soft bristle brush and fluoride toothpaste.

• Floss Daily – Floss using string floss, inter dental brushes or water flossers daily to remove plaque.

• Mouthwash – Rinse with antibacterial or fluoride mouthwash to reduce plaque bacteria and strengthen enamel.

• Drink Lots Of Fluoridated Water – Drink plain fluoridated water to encourage saliva flow to wash away any leftover sugars.

• Sealants – Ask your dentist to fit sealants onto your back molars. These are a plastic coating which will cover the deep grooves preventing foods and bacteria from getting in.

• Visit Your Dentist – Visit your dentist every 6 months.

11. What Is the Summary of Cavities and Tooth Decay?

• Cavities are caused by acids from bacteria eating away at essential minerals in your enamel.

• Avoid eating too many sugary snacks, acidic drinks and sticky foods.

• Brush your teeth thoroughly for 2 minutes twice a day using a soft brush and fluoride toothpaste.

• Floss daily.

• Drink plenty of plain fluoridated water.

• If you suffer from dry mouth then speak to your doctor/dentist to change your medication or use saliva replacements.

• Visit your dentist every 6 months.

12. What Are the Frequently Asked Questions About Cavities?

12.1 Can You Reverse A Cavity?

Only in the early stages can tooth decay be reversed. This is known as demineralisation and appears as a small white spot on your enamel. Using topical fluoride treatments, improving your brushing and cutting down on your sugar intake can help remineralise your weak enamel. However once the decay has caused a hole/pit in your enamel it cannot be naturally reversed. Your dentist will need to clean out the decay and fill it.

12.2 How Quickly Do Cavities Grow?

How quickly cavities grow depends on your oral hygiene, diet, saliva and location of cavity. On average it can take several months to a couple of years for the decay to work its way through your hard enamel. Once it reaches your softer dentin then it will spread much quicker to your nerve. Milk teeth (children’s teeth) have thin enamel so cavities can spread much faster.

12.3 Why Do Some People Get More Cavities?

Everyone will be different. Some people have more aggressive cavity causing bacteria such as Streptococcus mutans. Some people have deeper grooves in their teeth which can easily trap food. Some people don’t have as much saliva and some suffer from chronic conditions such as dry mouth. Everyone has different diets, brushing methods and fluoridated water.

12.4 Do Sugary Foods Cause Cavities?

Sugary foods will not cause immediate cavities however they will cause an instant acid attack lasting around 20-30 minutes. When you eat sugary foods the bacteria in your mouth will eat the carbohydrates creating acid. This will eat away at your enamel minerals. If you constantly have acid attacks and don’t brush, floss and neutralize your saliva over time your enamel will start to break down causing cavities.

Tooth decay can be prevented. By having good daily habits and early treatment from your dentist you can keep your natural teeth. Knowing how bacteria acids can affect your enamel, cutting down on sugary snacks, brushing and flossing your teeth well and visiting your dentist every 6 months will help keep your teeth. Take control of your oral health by booking an appointment for a routine diagnostic check up.