The human tooth is a carefully designed structure. It is designed precisely in such a manner that it is normally immune to external disturbances. However, an unhealthy tooth can have many abnormalities. The common abnormalities are the fissures and pits. Fissures are grooves present mostly in the back teeth and molars. Pits on the other hand, are depressions in the tooth surface. If left untreated, these deformities will worsen, creating more severe dental issues. A healthy tooth is therefore, is a structure that is properly sealed.

The tooth structure with defects like pits & fissures are very much vulnerable to the development of dental caries. Also known as dental cavities, these are infections that are mainly caused due to bacterial proliferation. Establishment of these cavities can lead to destruction and demineralization of the hard tooth layers. Therefore, it is very much necessary to prevent the formation of these structures. One effective way of doing this is by sealing the pits and fissures.

Comprehensive studies reveal that the potential of the dental cavities is directly related to the depth of the fissures and pits. In this case, the applications of sealants are very much effective in the aspect that they shall remain bond safe for a long period of time. These sealants are synthetic materials that are generally applied either to a single tooth or multiple teeth. They are usually applied to the chewing surfaces of the teeth, which happens to be portion which is the most vulnerable to bacterial attack. The application of these sealants shall prevent the trapping of food particles in these areas.

Dental sealants can therefore be defined as the materials that are introduced into the fissures & pits, forming a micromechanically bonded mechanical layer. This protective layer shall help in cutting off the bacterial attack. According to the American Dental Association, these are adhesive materials that function to isolate the tooth structure from the rest of the oral cavity.

Dental sealants were introduced in the year 1905 in the form of Sliver nitrate. The method was introduced by Miller. With technological advancements, these materials began to be applied by employing Ultra Violet rays. For initiating the setting reaction, UV rays of 365nm wavelength is normally used.

Pit and fissure sealants are categorized in several ways. Some of the criteria by which they are classified are as follows:

• Chemical constitution: Based on the chemicals used for synthesizing them, they can be classified into Nuvaseal (Methyl methacrylate ), Kerr pit and fissure sealant (Triethylene glycol dimethacrylate) etc.
• Generations: Pit and fissure sealants can also be classified on the basis of their evolution. The 1st generation (Nuvalite, Alphalite etc) sealants used UV light whereas the 2nd category (Delton, concise white sealant) was a self-cured one. This was followed by the 3rd generation (Stephen K W Strang) wherein blue visible light was employed. Finally, the 4th generation came and this era saw the introduction of the method called fluoride releasing. Examples of these sealants are Jack Toumba, Toma L.Morphis etc.
• Filler content: Pit & Fissure sealants can be either filled or unfilled. Both the categories have their own pros & cons. Unfilled sealants have the advantages of more retention, better flow etc. The filled sealants on the other hand are more resistant to wear & tear. However, these materials need occlusal adjustments.
• Color: Pit & fissure sealants can be of different colors. The colored sealants give an aesthetic feel, however it is very difficult to identify as time progresses. Another category of colored sealants is the white tinted/opaque sealants. These materials contain titanium dioxide, responsible for giving the color. Colored sealants are very easy to identify. Example of such sealant is helioseal.

Although the sealants play a pivotal role in oral hygiene, they do not remove the need for fluoride application. In fact, sealants and fluorides work together in the maintaining oral health. Application of sealants at the right time is much better than cavity filling. In this regard, they can efficiently save time, money and most importantly oral hygiene!