Tooth decay, which is also known as dental cavities or dental caries, is the destruction of the outer surface of (enamel) the tooth .the action of bacteria that lives in the plaque, which is a sticky whitish film formed by a protein in saliva (mucin) and sugary substances in the mouth. This produces acid which its attack often leads to decay of tooth

Factors affecting tooth decay
Your current state of oral health
Food or beverages consumed
Bacteria in plaque

Food or beverages consumed
Eating sticky foods or refined foods can increase the acid attack and makes saliva difficult to repair and prevent tooth decay, foods and beverages that are consumed for a long time may imbalance the remineralisation/ demineralisation process in favour of tooth decay process

Bacteria in plaque
Several micro organisms found in the mouth can cause tooth decay (Lactobacillus ,streptococcus mutants) The food sugars used by bacteria converts it into lactic acid dissolves  the minerals in the enamel creating holes or pits in the teeth (cavities). As the decay spreads to middle layer (dentine) the tooth becomes more sensitive to temperature and  touch ,when the decay reaches the innermost layer (pulp) results in  inflammation (pulpitis)  produces tooth ache

Your current state of oral health
It includes everything like how your teeth are shaped, formed, positioned, your saliva, dental treatment and oral health habits. Saliva is more important as it can slows the loss of mineral from teeth and replacing remineralisation process

Tooth ache in children

Baby bottle tooth decay or Nursing bottle caries is common in nursing child; the bacteria in the mouth use the sugar to produce acid that destroys the child’s teeth. The upper front teeth are severely damaged

Diagnosis
Sensitivity to cold and hot things
Discomfort in eating sweet foods
Dark spots is seen on teeth
X ray for finding the extension of tooth decay

Treatment
Removing the decayed tooth structure from teeth and filling it with silver amalgam
If decay attacks the pulp Root canal treatment is suggested

Prevention
Eating proper foods at right time during meals
Avoiding snacks or foods between meals
Brush your teeth with fluoride paste twice a day and rinse mouth with fluoride in water
Flossing