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.
An onlay is the same as an inlay, except that it incorporates a replacement for a tooth cusp by covering the area where the missing cusp would be. Crowns cover all surfaces of the anatomical tooth crown. 1 Inlays 1.1 Comparison of inlays and direct fillings.