Which of the following methods is an example of intra-uterine contraception?

An intra-uterine device (IUD) is a form of contraception that is placed inside the uterus to prevent pregnancy. It operates by interfering with the sperm's ability to reach the egg and may also prevent a fertilized egg from implanting in the uterine lining. There are two main types of IUDs: hormonal and copper. Hormonal IUDs release hormones that thicken cervical mucus and thin the uterine lining, while copper IUDs create a hostile environment for sperm.

This makes the IUD a distinct method of contraception, as it provides long-term protection (up to several years) and does not rely on daily medication or application methods. Other options presented do not fit the definition of intra-uterine contraception. Oral contraceptive pills are taken orally, Implanon is a subdermal implant, and dental dams are barrier methods used for protection during oral sex. Thus, the IUD is the only option listed that is classified as intra-uterine contraception.