Sealants are a great way to protect against tooth decay and cavities on your back teeth (molars and premolars). These are the teeth that are most vulnerable to cavities and decay because they are used in the chewing process, and are the most difficult to reach and clean. Molars first come in at around 5-7 years of age, with a second set coming in between the ages of 11-14. It is best to have a sealant placed when the molars first come in to ensure they are protected early.