I ATTENDED in the USA the annual session of the American Dental Association of which I am a member. One of my updating courses was implantology which basically involves metal tooth replacements that are anchored to the bone of the dental ridge. They bring us a step closer to tooth replacements that look natural and feel secure.

The evolution of implants has steadily progressed since the late 1950s, when titanium was introduced as a biocompatible metal that would eliminate biological rejection. Titanium has been a significant factor in accelerating the practice of implantology.

Today about 90 per cent of general dentists suggest implants to carefully selected patients. Implants should be considered an option when a patient cannot gain comfort in wearing a conventional, removable full or partial denture because of physiological problems (sore spots or a poor ridge) and/or psychological (gag) problems, or as an option to placing a bridge to replace a single tooth because so much healthy tooth structure has to be removed in order to accommodate the crowns. But for this author, Guyanese must first know that a single tooth implant generally costs nearly half a million Guyana dollars and the process takes almost a year.

Implants can provide support for one or more teeth so a crown, a fixed bridge, or an overdenture can be placed in the mouth. Although a single dentist may perform the entire implant process (as I do, since my training course taught me such), frequently two or more dentists are involved as a team. Before you are accepted as an implant candidate, your dentist will perform a thorough clinical examination and a complete medical and dental history. As a standard procedure, sometimes if necessary a dentist will refer the patient to either an oral/maxillofacial surgeon or a periodontist for surgical placement of the implants. Then the primary dentist makes and fits the replacement teeth.

Implantology is not one of the eight dental specialities, and the training and experience of those who perform implants vary, it is a complex procedure that requires specific knowledge and training.
Implants have three components: the anchor (which may be surgically placed in the bone), a post (which is attached to the anchor), and the artificial tooth (which attaches to the post).

There are several types of implants on the market, but at this time I only consider two to be safe. They are the endosteal and the subperiosteal.
Endosteal implants are placed directly into the jawbone. This implant cannot be done unless the patient has adequate bone support. First, an anchor is placed surgically into the jaw. For best results, the dentist must do minimal damage to the tissue.

Anchors are available in several shapes and are sometimes coated with a material that enables the bone to adhere to it. This process of attachment is called osteointegration (the bone integrates or bonds with the implant material). After the anchor(s) is/are submerged it is left undisturbed for three to six months to allow it to firmly adhere to the underlying bone. Then a second surgical procedure is usually needed to connect the post. This type of implant is often used to secure a fixed bridge.

A subperiosteal implant consists of a metal frame that rests upon the jawbone just below the gum tissue, instead of being placed directly into the jawbone. The metal frame is made by using impressions of the surgically exposed jawbone. After the frame is constructed, the gum tissue is reopened and the frame is fitted onto the jawbone. The implant adheres to the jaw as the gum tissue heals. The posts of the implant protrude through the gum. This type of implant is often used to secure an overdenture (a tooth replacement for an entire arch that is permanently secured to the implants).

Despite their high success rate some implants are physiologically rejected, must be removed. The primary reasons for failures include peri-implantitis (bony infections), placing the crowns on the anchors prematurely, and insufficient or improper alignment, persistent discomfort, and cosmetic problems. I was taught that patients with a history of periodontal (gum) disease may be a greater risk for peri-implantitis because of a higher frequency of periodontal bacterial and increased susceptibility to these organisms.

I believe that dental implants are not for everyone and I would stress that all implant candidates must be carefully screened. Candidates must be in good health, have healthy bone and gingival to support the implant, be psychologically suitable, and be committed to meticulous oral hygiene and regular dental visits. While the procedure usually takes about nine to twelve months to complete, implants can last 10 years or longer. Never assume anything is permanent. You will lose your implant if you do not take care of it.