Pits and Fissures Trap Food While Eating
Almost all cavities occur where after every meal or snack, food is left trapped between teeth and inside grooves on chewing surfaces where the brush cannot reach, and carbohydrate like sugar is changed to acid. http://ndk.biz/slideshow PLEASE WAIT FOR SLIDES TO LOAD  

Chewing a few nuts on each side of the mouth before eating, helps prevent food being trapped and changed to acid while eating.
Chewing fibre like celery after eating helps saliva remove trapped food, neutralise acid and repair demineralised tooth.
Chewing a special fibre after flossing then brushing, helps the saliva fluoride mix reach between teeth and inside pits and fissures.