With their deep grooves, teeth are hard to keep clean. Sealants are one way to protect teeth from cavities. A sealant is a plastic material usually applied to the chewing surfaces of the back teeth. The plastic resin bonds into the depressions and grooves of the chewing surfaces of the teeth and acts as a barrier that protects enamel from plaque and acids. The sealant is painlessly applied and costs about 65% less than a regular filling.