Surface piercings are any body piercings that take place on the surface into the body through areas which are not particularly concave or convex which is a surface flap of skin, rather than through a piece of body tissue from one side to another. A surface bar follows the plane of skin, while a standard piercing is pierced through the plane.
Sometimes surface piercings are difficult to heal, due to the daily activities that takes place, and which the body rejects the jewelry as a foreign object. Proper placement and jewelry selection by an experienced body piercer can help alleviate this problem. A well done surface can last for years, but still even not many do last, maybe anywhere between 3 months.
The best jewelry to be used in a surface piercing is a surface bar, though some might have success with PTFE bar due to its flexibility and non stainless steel.