What is used to make dental sealants?

Almost white filling. Technically it's called an unfilled resin, aka plastic but....You should think of it as a soft white filling used to reduce the risk of getting a cavity on that surface of the tooth. Generally used on children ages 6 and up.
In short, plastics. Sealants are bonded to small discrepancies in teeth before they can decay. All bonded materials are plastic resins. Sealants are low-viscosity resins, thus they can flow into, and seal, these discrepancies. Think of sealants like wrapping a tooth in saran wrap. The brands I use are BPA-free.
Dental sealants . Sealants are made from a resin or acrylic that is bonded to an etched tooth surface. This material can be made of bpa.