Sealing cracks
The sealing cracks is carried out by the dentist on the occlusal surfaces of the teeth of children. Food debris can get stuck in the deep fissures that exist on the occlusal surfaces of teeth and subsequent cause cavities. The sealing liquid fills the crack, preventing debris and bacteria from accumulating which facilitates cleaning the tooth surface. The liquid sealer is applied in the grooves of the tooth after first dried tooth or have isolated by a sheet of rubber. At this point, the liquid is fluid enough to penetrate easily into the furrows. The liquid hardens or luting alone or under the action of a special light. To be effective, this seal must be made as soon as possible after the eruption of the tooth.
Fluoride varnish 
While sealing cracks protect the occlusal surfaces, a fluoride varnish will protect all dental surfaces. Fluorinated varnishes have a very high concentration of fluoride (20 times that of toothpaste), but it is used in very small quantities so as not to be harmful. Once implemented, this will release fluoride varnish for several hours. The varnish can be used on children to prevent cavities or on adults for the prevention of tooth decay or dental calm sensitivities. The dentist tooth dry slightly and then apply the varnish with a small brush or any other method. Some are tinted varnish fluorinated to help their development, but to dissolve as the active ingredient is released. The coating dries quickly and the patient can immediately resume its activities.