Dental implants have been around for many years, way before we can imagine.
In ancient times, different materials had been used in the attempt to replace the missing teeth. Gold, silver, shell, porcelain and precious stone etc. were found embedded in the jaw bone to replace the missing teeth. In more modern times, metals like Vitallium, stainless steel, cobalt-chromium-molybdenum, titanium, titanium oxide and even zirconia have been used as dental implant materials.
The structure of implants evolved from using a monolithic (one piece) design – the roots and crowns are one single piece – to the polylithic (two or more pieces) design – the roots and crowns are two or more different pieces, with the crown firmly attached to the root. In the latter design, the roots are usually planted into the jaw first and then the crowns were attached to the roots once they are firmly integrated with the jaw bone.
The shape of the implants can be like a solid root form or a hollow cylindrical form inside the jaw bone, a long narrow screw in the bone (called mini-implant), a saddle shape resting on the jaw bone, and a blade form inserted into the bone.
Nowadays, dental implants are generally made with titanium metal because of its excellent biocompatibility and strength. Ziconia implants are very biocompatible but can be cracked under repeated heavy loading. The shape is usually a solid cylinder that is either taper or not, with threads on it.
The implants are first planted into the jaw bone to let the bone cells to approximate very closely to the surfaces of the implants (osteointegration). Once the implants are solidly integrated with the jaw bone, a tooth shape crown is then attached to the implant directly or to an intermediate adaptor by either a screw or with special dental glue called cement. As one can imagine, the removal of the crown from the implant is easier if the crown is attached to the implant by a screw than if it is cemented, in the event that the crown needs to be replaced or serviced. So, screw-type crowns are preferred by most dentists or oral surgeons.
Dental implants are not just used to support a crown, they can also be used to support a dental bridge for a long space, or for hybrid bridges for the full upper arch or the lower arch of teeth (all-on-4 or all-on-6). Implants are also useful in keeping dentures stable in certain patients by using clips or buttons.
Most people may not realize that implants are also used to facilitate orthodontic teeth movements by using the implants as the anchors. Obviously the implants are there just during the active treatment phase and are removed after the treatments are completed.
Although, implant-supported teeth will not get cavities, it can break (cracked), or become loose. The first and foremost is infection and inflammation that lead to swollen gums around the implants (peri-implant mucositis). If the infection and inflammation at the implant continue unchecked, then they will start to lead to bone loss around the implant (peri-implantitis) that will lead to red bleeding gums, pus formation, pain and eventually loss of supporting around the implant.
Some factors can predispose someone to peri-implantitis, namely: poor oral hygiene practice, clenching and grinding teeth constantly, smoking, uncontrolled diabetes, poorly designed crown (too big, too long, too bulky or too high), autoimmune diseases and immune suppression.
In certain cases, the crown can be chipped or cracked due to high stress on the crown during chewing and biting. In other cases, the screw that attaches the crown to the implant can be fractured. So, patients who have dental implants should wear a night guard (made with some form of acrylic) to prevent over stressing the crowns, screws or implants.
Implants are not advisable for patients with uncontrolled diabetes, smoking habit, uncontrolled gum disease compounded with poor oral hygiene practice, Patients who have true allergy to titanium metal, history of bisphosphonate injection for osteoporosis, radiation therapy in the head and neck region at high doses, recent heart attack or prosthetic heart valve surgery, hemophilia, and patients with suppressed immune system due to autoimmune diseases or immunosuppressive drugs are not suitable to have dental implants at all.
Call your dentists near you to see if you are suitable for dental therapy. Dr. Wong at Affinity Dental Care in Burlington have extensive experience in placing implants. He is a fellow of International Congress and Oral Implantologists. If you are in the Burlington area and want to learn more about implants, call (289)-861-5111 to book a consultation appointment.