Teeth essentially can be thought of as having two main parts — the crown, the part above the gum tissues, and the root, the part that is suspended in the bone by the periodontal ligament which keeps the tooth in place.
A dental implant is actually a root replacement, but unlike the root of a tooth it becomes anchored in the bone of the jaw, formerly occupied by a tooth or teeth. The amazing thing about currently-used dental implants is that they actually fuse with or integrate into the bone. They are for the most part made of commercially pure titanium, a metallic substance used for many years in medicine and dentistry because it is not rejected by the body.
Dental implants were first introduced for people who had lost all their teeth and who had great difficulty with dentures, largely because they had lost so much jaw bone upon which dentures rest. Because dental implants fuse to the bone, they stabilize it and prevent further bone loss. Resorbtion is a normal and inevitable process in which bone is lost when it is no longer supporting or connected to teeth. Only dental implants can stop this process and preserve the bone.
Implants look perfectly natural as they emerge from the gum tissues to mimic natural teeth exactly. Materials used are essentially the same as for regular crowns to imitate natural aesthetics, function, and durability. Crowns are either directly connected to the implants themselves by tiny invisible screws in the back non-visible parts of the teeth, or they are cemented over little tooth-like receptors just like regular crowns.
Your dentist and/or surgeon will carefully examine your mouth and the site where the potential implant(s) are to be placed, make study models of your mouth to assess your bite, take X-rays to assess bone quantity and quality; and take photographs if there is an aesthetic concern.
The implant surgery is a relatively comfortable procedure usually carried out under local anesthesia with oral medication or intravenous sedation for anxious patients. Some minor vibration is generally experienced during the implant site preparation, but it is quite tolerable. Since the surgery is minimally invasive there is little post-operative discomfort, perhaps a day or two. The implant(s) need to be left for a period of two to six months to fuse with the bone. The healing time depends upon the bone density of the site; the more dense the bone, the quicker the integration. Following that, your dentist will make a crown which fits on the implant and will be exactly like a normal tooth both in form and function.