discuss the types of fissure sealants, and describe the technique for placement

Fissure sealants are a type of preventive dental treatment where a plastic material is placed in the pits and fissures of teeth. They are primarily used in children and teenagers to prevent tooth decay. There are two main types of fissure sealants: resin-based sealants and glass ionomer sealants.

1. Resin-based Sealants: These are the most commonly used type of sealants. They are BPA-free and are known for their durability and longevity. They are also resistant to saliva contamination during placement.

2. Glass Ionomer Sealants: These sealants are less durable than resin-based sealants but have the advantage of releasing fluoride, which can help to prevent decay. They are also more forgiving in terms of moisture control during placement.

The technique for placement of fissure sealants involves several steps:

1. Cleaning: The tooth surface is thoroughly cleaned to remove any plaque or food debris. This is usually done using a toothbrush, dental floss, and sometimes a cleaning paste.

2. Isolation: The tooth is then isolated using cotton rolls or a rubber dam to keep it dry during the procedure. This is important as moisture can interfere with the bonding process.

3. Etching: An etching solution (usually phosphoric acid) is applied to the tooth surface to roughen it up. This helps the sealant to bond better to the tooth.

4. Rinsing and Drying: The etching solution is rinsed off and the tooth is dried. It's important that the tooth remains completely dry before the sealant is applied.

5. Sealant Application: The sealant material is then applied to the tooth surface using a small brush. It is placed into the pits and fissures of the tooth.

6. Curing: The sealant is then hardened using a special light. This is known as curing.

7. Checking: Finally, the dentist will check the sealant to make sure it's properly hardened and covering all the pits and fissures.

Regular check-ups are necessary to ensure the sealant remains intact and effective.