The morphology or shape of our teeth is the result of millions  of years of  evolution.  Although extremely well designed for biting and chewing, our teeth have certain features that make them vulnerable to decay when exposed to today's highly processed foods. 

The occlusal or biting surfaces  of our teeth have pits, grooves and fissures.  These small crevices enable some food to remain even when brushed properly.  Unfortunately, bacteria which are always lurking around, take this opportunity to thrive in these areas. Given enough time, decay eventually occurs and a filling is usually required.

To maintain a healthy mouth preventing tooth decay is important, and sealants can offer major protection against cavities.

A dental sealant is a composite material that helps shield out decay-causing bacteria from the chewing surfaces of back teeth. This plastic resin bonds into the depressions and grooves (pits and fissures) of the chewing surfaces of back teeth and acts as a barrier, protecting enamel from plaque and acids. More than 75 percent of dental decay begins in the pit and fissure areas of the back teeth. The best time to apply them is when the six-year molars (the first permanent back teeth) appear. Adult molars , have deep grooves on their biting surfaces.  Because of their depth, sticky sweet foods like raisins, fruit rollups and of course candy may get stuck in them and remains there for 30 or 40 minutes after the treat is finished.  The enamel at the bottom of these grooves also tends to be very thin.  Thus, they are often the first places decay forms in the teeth.  For many years, before the advent of fluoride as a public health measure, many people lost their back teeth before they reached adulthood simply because these grooves were so susceptible to decay.  Even after the widespread use of fluoride in drinking water became common, the top surfaces of the back teeth tended to get decay and needed fillings.No drilling is required which makes this procedure an attractive option for young children.

The chewing surfaces of the teeth to be sealed are first cleaned with pumice which looks a bit like fine beach sand.  This buffs the surface of the enamel and prepares it for the process of bonding.

With the teeth kept dry , a gel containing dilute phosphoric acid is applied to the buffed biting surface of the tooth.  This is allowed to remain on the enamel for about 15 to 30 seconds, and is then washed off.  After drying the tooth, the surface looks chalky white which is evidence of the microscopic hills and valleys caused by etching the surface.

The liquid plastic sealant is applied over the etched enamel.  The plastic flows into the etched mountains and valleys and then pools in the grooves in the top of the tooth.  A bright light is then shined on this liquid plastic, and it hardens into a glasslike coating over the surface of the tooth.  

As long as the sealant remains intact, the tooth surface will be protected from decay. Sealants hold up well under the force of normal chewing and usually last several years before a reapplication is needed 

The success of dental sealants depends on cooperation of the child during the procedure! For a sealant to be successful for a long time, the child MUST be able to understand what the dentist is trying to do and be willing to keep the mouth open and the teeth dry for the duration of the procedure.  If the teeth get wet between the time the acid gel is washed off, and the time the final cure is done with the light, the sealant will either not adhere to the etched surface, or may only partially adhere.  Sealants fail all the time because they are attempted on children who are too immature to cooperate.