This is the third installment of a three-part series on dental implants. Prior to implants, patients who had lost all of their teeth or had terminal dentition (facing loss of all their teeth) faced years of progressive pain, difficulty in eating, and social limitations due to poor fitting, and many times, unaesthetic dentures.
Dr. Branemark, who pioneered titanium integration to bone, described these individuals as dental cripples. We have spent decades developing techniques to return the patient’s quality of life and ability to function. Modern surgical techniques are geared toward minimizing the number of implants needed to establish successful long-term support of a prosthesis (denture). A second surgical goal is to place implants in a way to minimize the need for extensive bone grafting normally used to replace atrophied bone. This helps to minimize the pain associated with treatment and also drastically decreases the cost of treatment.
Rehabilitation of patients with terminal dentition or who are already missing their teeth is best provided by a team approach. Implants are placed by a surgeon, and the prosthesis is fabricated by a specialist in restorative dental care. Long-term studies have shown a 98% success rate with this treatment model.
When looking at replacement options for a patient, an individual has two choices available for implant-supported prostheses. The first is for a removable denture. The second is a permanent, non-removable prosthesis.
The removable implant-supported denture is the more affordable of the two options. Removable dentures supported by implants offers a drastic improvement in function and comfort over a standard denture. Dentures on the mandible (lower jaw) are usually more difficult for patients to tolerate. There are options for placing either two or four implants. The more implants placed, the more stable the prosthesis, and the smaller overall size of the denture. The denture usually attaches to the implants via nylon bushings called locator abutments. The over-denture is certainly an upgrade from the full denture but still has some limitations. They need to be removed at night. Food will become trapped below the prosthesis during eating, and certain foods can still cause the denture to be dislodged.
The second choice for replacing missing dentition is that of a permanent implant-supported prosthesis. The fixed bridge comes in many forms, depending upon the patient’s clinical presentation and wishes. The fixed bridge comes closest to replacing the patient’s natural teeth. A fixed prosthesis is a much more complex process, taking more time to coordinate between the surgeon and restorative dentist. The mandible is the most popular jaw for this type of denture since the patients find removable dentures much more difficult to tolerate. The lower jaw in most cases has better bone volume and quality. Therefore, a permanent bridge can be supported with as few as four implants. Professionals use the term “All-on-4” to describe this technique. Many times implants placed to support a removable denture can be transitioned to support a fixed permanent denture.
The maxilla (upper jaw) has more surgical and prosthetic options due to the fact that the restoration of the upper dentition is more complex. The upper prosthesis must have acceptable aesthetics along with proper support, speech, and function while working with bone that has poorer quality and quantity when compared to the mandible. The surgeon uses the bone available to place stable implants that will give long-term function. These fixed bridges are more costly, due to the fact that implant-supported dentures require complex and precise laboratory support in fabricating these dentures.
There is now a new option available for the mandible that gives the patient the option for a fixed bridge at the price of a removable denture. This concept is called Trefoil implants. This uses a pre-fabricated fixed bar supported by only three implants. Early studies have shown this to have good success rates.
Patients should be very careful when choosing a dental team to assist them in rebuilding their dentition. Dentistry has no specific requirements for training and there is no credentialing process for individuals advertising these services. The patient should ask the doctor about their experience and training with these complex procedures.