Egg

One half of an eggshell is floated in a milk-bottle top of vinegar. Observe how long it takes to demineralise the eggshell in the acid and think about how many meals or snacks or years it takes to develop a cavity.

Frequent carbohydrate consumption maintains continual acid attack on all tooth surf surfaces particularly in this photo of bottle caries.

Even though most plaque can be seen at gum margins of smooth accessible surfaces, few cavities occur where the brush, fluoride and saliva have easy access to remove plaque, food, neutralise acid and repair demineralised tooth after eating.

Almost all cavities occur where chewing pressure forces carbohydrate like sugar between teeth and inside grooves and where toothpaste and saliva can't gain access to neutralise acid and repair demineralised tooth.

Most food is trapped between teeth compared to that trapped inside grooves on chewing surfaces yet over 80% of cavities occur inside grooves.