eli5: How does dental filling become hard under UV light?


eli5: How does dental filling become hard under UV light?

In: 17

The chemicals inside it enter a reaction, which results in new material that is solid. Much like when you take a glowstick and “activate” it (by breaking glass vial inside and mixing two liquids), the chemical reaction causes it to start glowing.

UV reactive materials can be found in many parts of our world. UV reactive resin, for example, is used in construction or (more recently) 3D printing.

Looks like this was already answered; however, “Photopolymer resins” are resins that harden when exposed to a specific frequency of UV light, if you are looking for google words <3

Dentist here. I can’t answer the specifics of how the photoactivator compounds work, but just wanted to add that we actually don’t use UV light anymore – it’s been blue light for at least the past 20-30 years now (~470-480nm wavelength).

Chemical reactions need a certain amount of energy to happen. For things that happen spontaneously, that energy can come just from the ambient temperature. The material the fillings is made from gets the energy from the light, which knocks electrons and atoms around causing the reaction to happen and you’re left with a hardened filling.