Do not. In fact, this is a simple and painless procedure that only requires your dentist to close each tooth for a few minutes. First of all, your child's teeth are cleaned. A mild acid solution is then applied to the tooth surface. This will help seal the adhesive to the teeth. Finally, the sealant is applied and hardened to the teeth.
As long as the sealant remains, your child's teeth will be protected - usually for at least five years. Always check to make sure that the sealant is intact and working properly.