If a tooth with a gold crown breaks, it is generally because the underlying tooth structure has fractured or decayed. Gold crowns are not immune to becoming loose, especially if you are eating foods and candy that are harmful to crowns and bridges. Gold crowns also cause the least wear on the opposing tooth.
Making the world better, one answer at a time. An artificial boundary is a boundary made by humans, examples include dams, the fence at the border between the U.S and Mexico. A natural boundary is a boundary made by nature, a boundary that happens naturally, examples include rivers, mountains and such.
Typically the boundary is the thread of the channel, under a rule that the United States inherited from England, where it applies to boundaries between counties. There are at least three exceptions, where the boundary is one bank of the river rather than the thread of the channel: 1  The boundary between New Hampshire and Vermont is the west bank of the Connecticut River. 2  This was established as the eastern boundary of New York by a grant of King Charles II in 1664.