Phencyclidine (PCP) was originally developed as an anesthetic, but the adverse side effects prevented its use except as a large animal tranquilizer. PCP acts as both a depress â¦ ant and a hallucinogen,and sometimes as a stimulant. It is abused primarily for its variety of mood-altering effects.
1 An inlay- As the name suggests, this restoration sits inside the tooth.  An onlay- In contrast is bonded on top of the tooth, replacing some or all of the cusps of the tooth.
Onlays and 3/4 crowns are variations on the technique of dental crowns. The difference between these crowns and the crowns discussed previously is their coverage of the underlying tooth. The traditional crown covers the entire tooth; onlays and 3/4 crowns cover the underlying tooth to a lesser extent.