Dental Implants
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Dental implants are changing the way people live. They are designed to provide a foundation for replacement teeth that look, feel, and function like natural teeth. Individuals whom have lost teeth regain the ability to eat virtually anything and smile with confidence, knowing that their teeth appear natural.
What are Dental Implants?
The implants themselves are small titanium posts that are surgically placed into the jawbone where teeth are missing (figure 1). These metal anchors act as tooth root substitutes. The implants become integrated with the bone, meaning the bone adapts to the titanium surface creating a mechanical and biological bond that anchors the implant preventing movement. Once integrated, the implant has attachments which protrude through the gums and allow tooth fabrication similar to that seen with crowns and bridges. The presence of the implant in the bone helps preserve bone structure and prevent bone deterioration, or atrophy, which occurs over time in areas where teeth are missing.
Presurgical Evaluation
The placement and reconstruction of dental implants is a team effort. It usually requires a surgeon who places the implants in the bone and a restorative dentist who then makes the teeth which are to be anchored by the implants. Before anything can be done a thorough oral examination must be done by both members of the team. The restorative dentist will determine the dental needs of the patient and establish the health of the remaining dentition. The surgeon then will look at the areas of bone missing the teeth to determine whether there is sufficient bone structure and quality overlying soft tissue which can support the type of implant reconstruction necessary to replace the teeth. It is at this time that bone augmentation procedures and soft tissue grafts may be planned to establish the proper foundation for the implant. Depending on the location in the jaws, bone grafts can be done simultaneous with implant placement or may need to be done in advance to prepare the bone for locating the implant appropriately. Often, when teeth are lost prematurely, healthy gum tissue, which is necessary to preserve the health of the bone around the implants, may need to be grafted to this area prior to implant reconstruction as well. All of these things should be taken into consideration before implants are actually planned for a particular site. It is much easier to deal with these problems before the implant is in position to be restored than to try and reestablish bone and/or soft tissue after the fact.
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Periodontal disease in patients who still have their teeth or in patients who have lost all of their teeth, is important to determine from the history. Many patients have immune systems which cannot deal with some of the bacteria that are known to cause gum disease around teeth. These same types of bacteria can cause similar problems in patients with implants as well. It is very important to have any and all periodontal problems under control prior to the placement of implants in patients who have teeth, and to establish a healthy environment where there is no residual infection in patients who have no teeth.
Hard tissue grafts may include bone that is harvested from the patient, either from a source inside the mouth (figure 2) or from sources outside the mouth such as the hip or lower leg (figure 3). These grafts may be used to augment the sinus (a sinus lift procedure) to increase the vertical height of bone available in the posterior maxilla where bicuspid and molar teeth are missing (insert animation). This is often necessary because of bone loss due to periodontal disease, atrophy due to loss of the teeth, or an excessive size of the sinus where the floor dips down very close to the bony ridge. The purpose of this graft is to increase volume in anticipation of implant reconstruction whether for fixed bridgework or overdentures (figure 4). Onlay grafts using blocks of bone from the jaws may be used to correct a narrow ridge, too thin to accommodate an implant (figure 5 & 6). Newer techniques utilizing banked bone in combination with genetically engineered proteins which induce bone formation, may eliminate most if not all of the traditional bone graft harvest procedures. Your doctor will discuss with you the pros and cons of different types of bone graft sources as it applies to your particular situation.
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Soft tissue grafts are often used to bulk out areas that are too thin to help maintain the health of the gum tissue surrounding the implant as it emerges from the bone or to reestablish the normal contour of the gum tissue so that it resembles the natural condition (figure 7). Again, the decision to do these procedures should be in advance of any final restorative effort.
What Types of Prostheses are Available?
A single prosthesis (crown) is used to replace one missing tooth – each prosthetic tooth attaches to its own implant (figure 8). A fixed partial prosthesis (bridge) can replace two or more teeth and may require several implants (figure 9). A complete dental prosthesis replaces all of the teeth in either the upper or lower jaws. The number of implants required varies depending upon the type of complete prosthesis recommended and the quality of the available bone. A removable complete prosthesis (overdenture, figure 10) attaches to a bar or ball/socket attachment, whereas a fixed complete prosthesis (figure 11) is permanently screwed into the implants and is removed only by your dentist.
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Surgical Procedure
For many patients, the placement of dental implants involves two surgical procedures. First, implants are placed into the jawbone. For the first several months following surgery, the implants are beneath the surface of the gums gradually bonding (integrating) with the jawbone. You should be able to wear a temporary complete or partial denture to replace the missing teeth and eat a soft diet during this time. At the same time, your dentist is preparing to fabricate new replacement teeth (figures 12, 13, & 14).
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After the implant has bonded (integrated) to the jawbone, the second phase begins. The implant(s) will be uncovered and a post will be attached to the implant that protrudes through the gums and will act as the anchor for the artificial tooth (teeth) (figure15). When the artificial tooth (teeth) are placed these posts will not be seen (figure 16). The entire procedure from surgery to final restoration usually takes 3-4 months. Most patients experience minimal disruption in their daily life after the first several days following surgery when there may be swelling and discomfort.
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Surgical Advances
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Using the most recent advances in implant technology our doctors are able to place single stage implants. These implants do not require a second procedure to uncover them, but do require a minimum time of healing before artificial teeth are placed. This time frame will be determined by the surgeon and is often not known until the implant is actually placed. There may be situations where the implant can be placed at the same time as the tooth extraction, further minimizing the number of surgical procedures.
Occasionally, when teeth are extracted, it is best to delay placement of the implant. The implant may not match the size and shape of the socket and therefore 6 to 12 weeks of healing may be necessary before implant placement. In a small number of cases, the bone loss around the tooth being extracted will not be adequate for immediate or delayed implant placement, and a ridge preservation bone graft will be recommended (figure 17). This will improve or preserve the shape of the ridge in anticipation of an implant that will be placed in the future. Generally a minimum of 4 months of healing will be required before an implant can be placed.
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Other techniques are available to restore severe bone deficiencies. Zygomatic (cheek bone) implants (figure 18) may be used in severe maxillary atrophy where bone grafts are not practical or possible. Distraction osteogenesis (figure 19) may also be used for focal bone defects and may result in bone suitable for implant placement faster than waiting for a bone graft to mature.
Patient Information
Every patient must consent legally to their proposed treatment. There are often multiple options that must be choosen from to determine the right course of treatment. With each treatment plan there are potential complications which must be disclosed before proceeding. When implants are placed in the bone there is the possibility of infection, nerve injury, sinus exposure, injury to other teeth and bone, and/or anesthesia complications. While the majority of these complications are rare, some of them may be permanent. The individual situation will determine the relative risk of these untoward events. While dental implants are very predictable and have shown high success rates and long-term stability, failure and loss of implants are possible. Implants are no longer considered experimental and when the conditions are correct success can be greater than 95% predictable over a 20-30 year period. You should realize, however that any device that functions is subject to wear. Routine follow-up and self care are critical to long-term success. While dental decay and corrosion of the implant parts is highly unlikely, peri implant disease or gum disease is still something that needs to be monitored on a regular basis. The restorative dentist will likely suggest follow-up every 3-4 months for at least a year to insure maintainance of the surrounding soft tissues and bone with prevention of inflammation or infection.
Early implant failure can be due to a number of factors but most commonly is related to either infection or nonintegration. Infections may be related to failure of soft tissues to protect from the normal bacteria that occurs intraorally. Fortunately, these types of infections are very rare. Prolonged antibiotic use in the first 1-3 weeks after surgery will likely be recommended. Late implant failures may be related to illness and medications. Uncontrolled diabetes or some medications may affect implants just as they may affect other types of metal joint prostheses. Lack of homecare is the single most common reason for late implant failure. Regular dental appointments for hygiene and maintenance will help retain implants as long as possible. Biomechanical failure can occur with the implant parts. Most implants are a two-part system with the implant imbedded in the bone and a prosthetic attachment which is screwed into the implant. This attachment may fracture if the forces placed on it create stresses that it cannot support. Fortunately, in many situations the attachments are stock and can be replaced without having to replace the overlying crown or superstructure. Unfortunately, if the crown or superstructure is custom made to a custom abutment, the overlying prosthesis may need to be remade even though the implant is still functional. Finally, bad habits such as tooth grinding and smoking will adversely affect the long-term success of implants. The surgeon will advise quitting smoking at least during the surgical procedures and the integration phase of the implant. Because research has shown that smoking is probably the single most important factor in the development of gum disease, seriously consider quitting smoking if implants are to be placed.
What Type of Anesthesia is Available?
Many single tooth implants can be placed under local anesthesia. Often these are less traumatic than the extraction that created this edentulous space. If fear and anxiety are a major factor then inhalation sedation utilizing nitrous oxide analgesia, or intravenous sedation utilizing sedative and general anesthetic medications are especially worthwhile to eliminate the stress of worrying about a surgical procedure. Particularly long and extensive procedures can be performed in our outpatient facilities at the University Oral and Maxillofacial Surgery offices. We employ an anesthesiologist to provide controlled general anesthesia which allows maintainainance of vital signs and safety throughout the procedure. This not only frees the surgeon to concentrate on the surgery, but allows the surgery to be completed as quickly as possible for safety and comfort. Following the surgical procedure patients are closely observed in our office during recovery. Prescriptions for pain medication and antibiotics are prescribed, and oral rinses consisting of an anti-plaque agent as well as an oral antibiotic are used in most cases. Written discharge instructions which will be reviewed prior to discharge. When fully recovered from the anesthesia patients are escorted to the car by one of our trained staff members. For at least 24 hours after any sedation do not plan to drive, operate machinery or make legally binding decisions as one is under the influence of the anesthetic medications or any medications taken for pain control at home.
Postoperative Care
Following surgery instructions as to how to contact us in case of an emergency at night or on the weekend will be provided. We want to assure our availability to handle any and all problems following our surgical treatment. A doctor from our practice is always on call and may be reached 24 hours a day. Generally, a one week postop appointment will be made prior to the surgical procedure. At this appointment an oral examination will be performed to determine how healing is progressing. Any changes in diet, medications, or physical activity will be discussed at this visit. Do not assume that feeling good automatically allows resuming normal activities without checking with your surgeon first. During the integration phase of treatment, exercise, chewing, and normal oral hygiene may be resumed, when okayed by the surgeon, until the second phase of treatment begins which involves loading of the implant and restoration. The surgeon will determine when the implant has integrated through the use of x-rays as well as testing the implant directly. If an implant is lost due to nonintegration the surgeon will remove it, evaluate the site and prepare it as necessary for replacement of the implant. There should be no additional cost because it is our intent to fulfill our responsibility of providing a restorable implant to the dentist for completion of treatment.
Why Choose Dental Implants?
The research and advances in technology that have occurred over the last 20 years make dental implants very predictable and the long-term prognosis is excellent when they are used properly. That is why we here at University Oral and Maxillofacial Surgery will counsel you as to the best way to restore your particular problem area. Our doctors have extensive experience both clinically as well as with new research advancements so that we can stay on top of new developments and implement them for you as soon as we determine them to be clinically viable. Once the implants have integrated and we send you to your restorative dentist this does not mark the end of our treatment. We stand by our work and expect you to see us with any and all problems you feel are related to our treatment. We take special pride in always being available to help in the maintenance and/or repair of implants that we have placed.
We urge you to find out as much as you can about the implants, especially once you become aware of your particular needs. The internet is a valuable resource where you can find a lot of information regarding implants, particular implant systems, bone grafts, soft tissue grafts, and newer bone graft materials. We will be happy to direct you to those sites that can give you more information about different materials and techniques which may specifically relate to your treatment. Our goal is to make you as informed as we can so that you can make the right decision and participate in your treatment planning.