Sealing is a method of preventing dental decay, used both in pedodontics (pediatric dentistry) and adult general dentistry. It is usually indicated on the teeth that are not affected by caries.
It consists in applying of a very thin layer of flowable composite (dental sealant) on the chewing surface of the teeth in the grooves and fissures, and sometimes on lingual and facial surfaces.
The sealant remains there as a thin tooth-colored foil and acts as a barrier against pathogens that lead to cavities (dental plaque).
It is a minimally invasive method of prevention because it doesn't need tooth polishing before application, unlike the treatment of already formed cavities.
Unlike the usual smooth enamel surfaces, deep dental grooves accumulate food debris that sometimes are difficult to remove by brushing, especially on freshly erupted teeth.
Most teeth caries on children's teeth start from the grooves and the fissures found on the occlusal surface.
Most of the times the sealants are indicated on the kids' first and second permanent molars.
It is best to carry out the sealing before any evidence of dental caries, so once a tooth has been identified as a good candidate it should be sealed as soon as possible, ideally within the first year after its eruption.
Sometimes, even if there are early signs of tooth decay (incipient caries), molar teeth can still be sealed, but with prior complete removal of the decay. But this is to be determined by the dentist as appropriate.
The decay is caused by acids resulting from the digestion of food by the bacteria that live in the dental plaque (the whitish layer that forms on the teeth a few hours after eating). Brushing your teeth helps remove this layer, preventing cavities. The problem is that on a dental surface with very deep grooves brushing is not as effective.
The sealant applied in these grooves transforms the surface into a much smoother and easier to brush surface, food debris not having any place to hide anymore.
Another aspect is that where there are deep grooves, the enamel is thinner and bacteria have less to go until they reach the dentin, so the sealant applied thickens the enamel wall in the area hindering their access even more.
Fluid composite applied as a sealant contains fluorine antibacterial substances that are issued continuously over a long period of time, for an even better protection from tooth decay.
The first molar (6 years old)
These teeth erupt between 5 to 7 years old and are the most commonly sealed teeth. Although teeth are meant to be used throughout the whole life, they appear at an age when eating habits and most importantly dental hygiene are not well developed and performed by children. In reality, these molars are the most susceptible to teeth decay.
The second molar (12 years)
Second molar appears between the ages of 11 and 13. At this age, it is much easier to appreciate the risk of dental caries and oral hygiene of the patient. Even if sometimes the surface of these teeth does not absolutely require sealing, it is better for them to be sealed because they are susceptible to tooth decay.
Other permanent teeth
Sealing can be carried out on other permanent teeth if necessary, depending on the case. One good example is the palatal fissure on the back surface of the upper incisors, if it is highly emphasized.
Temporary teeth (milk teeth)
The attitude towards milk teeth (decidual dentition) is different from that towards the permanent teeth. Sealing is not necessary for the milk teeth.
Teeth of adult patients
Typically adult teeth have areas of abrasion (blunt) and their surfaces are no longer so pronounced. If they had deep fissures they are probably already affected by caries or already treated, but if there still are some teeth with a steep relief, unaffected by decay and untreated, the sealing process is still indicated.
Also read some Tips to prevent Teeth Cavities.
Sealants that remain intact for 2-3 years are considered by doctors a success, but if the sealant needs repair sooner than 2 years that is not necessarily considered a failure. Due to the small thickness of the applied layer, sealing fractures are less resistant than ordinary fillings.
To ensure better protection of the teeth regular six-monthly visits to the dentist are needed to check the sealants' integrity.