SurgiMac's Automatic Crown Remover Gun Type Spring Loaded with 4 Tips and Adjusting Wrench features the following functionality - 

• The Crown remover is a spring loaded mechanical device to remove the bonded crowns and bridges by an intensive impulse. The Cement layer breaks with the impulse and the crown or bridge can be removed easily.
• It also contains a straight rod that can be attached as safety purpose when not in use.
• Four different designs of tips allow engaging different types of crown margins. Impulse strength should be lowered for root treated teeth.
• Its spring is titanium made that retain its strength even after recurrent autoclaves.
• For permanent removal of crowns by breaking the seal between tooth and crown even after sectioning with a bur.
• The setting of the impulse to a higher level can break the underlying tooth. Be careful.