Light Initiated Polymerisation of Acrylates

An approx. 2 cm long piece of silicone tubing (inner diameter approx. 1 cm, closed at one end with a stopper) is filled with a photohardening mixture for dental fillings (available in dental shops; instructions for use can be found in the package leaflet). The open end of the tube is irradiated with UV light from an LED torch. Temperature and hardness of the sample are checked again and again with fingers.

• A gradual hardening of the material is observed. It heats up during hardening.