The implant is made of pure titanium, shaped like a cylinder, and has smooth, polished screw-like threads over it. The restorative side is a small elevated hexagonal platform, known as the ‘external hex.” A piece called the abutment, along with a gold screw, is attached to the implant. The restoration, which could be a denture, crown, or a bridge, goes on top of the implant.
The Branemark design was widely imitated by other companies, who were eager to enter the emerging dental implant market. However, none surpassed the Branemark in success or popularity. Many dentists consider the implant to be the best researched and documented dental implant ever. Today, it is still used worldwide. Yet, the Branemark is not perfect.
The Branemark’s procedure requires two surgeries. The first surgery is needed to place the implant into the jaw bone, after which it is covered back up with the gum tissue. The healing process takes up to six months.
After this long recovery time, patients undergo a second surgery, which ‘uncovers’ the implant and places a titanium cylinder called a healing abutment onto the external hex. Another three to six weeks of healing is required before the final impressions can be made and the patient can finally receive their new crown, bridge or denture.
This process takes a long time. Clinicians also noticed that the gold screw connection to the abutment was prone to fracture under certain conditions. This forced patients to undergo time-consuming and costly office visits for repairs. However, this is not the most disturbing drawback of the Branemark design.
The implant-abutment interface of the external hex, once uncovered and exposed to the oral cavity, created a microscopic gap. It is unnoticeable to the patient or dentist but more than wide enough for microbes to get in. This so-called micro gap became colonized by bacteria resulting in a slow loss of bone around the implant platform. This was to be expected, even tolerated by clinicians because it generally did not result in failure and occurred very slowly.
Are there any other dental implants available for dentists to make this decision? Check back with us next week to find out.