Tooth decay occurs when acid is produced from plaque, a deposit on teeth where bacteria can grow.
The acid can dissolve the enamel in teeth, leaving behind unwanted white spots, said Marques. The spots can also be grey, brown or even black.
Tooth decay can lead to toothache, sensitivity and tooth loss.
The condition can be prevented by cutting down on sugary and starchy food and drinks, said the NHS.
Marques said: “White spots on the teeth can be an early indication of tooth decay, caused by acidic bacteria that can dissolve enamel.
“If not cared for properly, it can cause decay and ultimately tooth loss.”
Carbohydrate-rich foods and drinks provide bacteria in plaque with energy, which making acid at the same time.
If plaque builds up, the acid can begin to dissolve the surface of teeth, leading to tooth decay. Tooth decay can lead to sensitive teeth.
Gum inflammation is another sign you should see your dentist, said Marques.
It could be caused by a build-up of plaque, which has caused an infection.
Jaw pain could also be a sign of tooth decay. The pain could be caused by grinding teeth in the night, which will also make you wake up with a sharp headache.
A night guard could help to prevent further damage from grinding teeth in the night.
“It may seem obvious, but many people will ignore toothache if the pain subsides after a while,” said Marques.
“Get to your dentist as soon as possible, as there may still be a problem.”
Brush your teeth properly with a fluoride toothpaste twice a day to prevent tooth decay, according to the NHS.
In 2016, more than 34,000 under-10s were treated in hospital for tooth decay.