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.
Onlay Restorations, 3/4 Crowns & Crowns. Often patients will ask what is an onlay and how does an onlay differ from a crown. Both a crown and. an onlay are indicated when there is extensive tooth loss or to hold together cracked or thin tooth. structure.