What are dental implants?

Dental implants are metal posts that replace missing teeth. Most are made of titanium, which is a metal that is bio-compatible with human tissues. Titanium implants have been used for decades, without any known ill effects. They can be used in both the lower jaw (mandible) or the upper jaw (maxilla).

What advantages do implants give me?

Dental implants can be used in a variety of ways. In some instances they offer better solutions than conventional dental restorations. Implants are the only solution if removable or complete dentures are to be avoided. Here are some of the ways dental implants can be used:

• Dental implants can replace a single missing tooth. In this case, using an implant would avoid drilling the adjacent teeth needed to support a permanently cemented bridge. This is often desirable when the abutment teeth do not have any fillings. The reason? Tooth enamel is precious. It can’t be replaced once it’s drilled. The act of drilling, no matter how carefully it’s done, can still stress the tooth’s nerve. Sometimes, this compromises the vitality of the pulp tissue. When this happens, a root canal is needed. Another thing to consider is that as much as we’d wish otherwise, dental crowns and bridges do not last forever. They can chip or break, and decay can form under the margins, necessitating replacements. A single dental implant reduces the need for extra crowns and future dental work.
• Dental implants can replace a removable partial denture. Removable bridges are not always as firm and kind to the tissues as we would like. When they’re not, they tend to move around a bit, sometimes wiggling or loosening the teeth they rest on, which are called abutments. In time, abutment teeth can become loose and sometimes need to be removed. When this happens, a new, larger removable denture is needed. Removable dentures collect a lot of plaque, and make cleaning around some teeth quite difficult. And there’s always the chance that decay will form at the spot where tooth meets the gums in the remaining teeth. With implants, these problems tend to be avoided or, at least, minimized.
• Dental implants can replace a full upper or lower denture. Most people have enough bone remaining to have implants placed in their jaws. In the off-chance that there’s not enough bone, new techniques exist to regenerate the amount needed to successfully have implants.
• Dental implants can provide more retention for full or partial dentures. Instead of placing five, six, or more implants, two-four implants can be inserted for increased stability. When this happens, the final prosthesis will be more stable, giving a greater sense of security. Also, the prosthesis is often smaller than the one being replaced.
• Dental implants avoid removable bridges. Often, the loss of a critical tooth eliminates a fixed bridge as an option. Either there are not enough teeth to support a fixed bridge, or the span will be too long, or a critical abutment has been removed. Regardless of the cause, a fixed (cemented) bridge cannot be employed to replace the missing teeth, so a removable bridge is suggested. Is a removable bridge the only option to replace missing teeth when there are not enough suitable abutments? This is the time to consider dental implants.
• Dental implants can be used in complex cases in order to avoid a denture while the patient still has some teeth left. These patients usually have existing bridges, and they are certainly not strangers to the dental chair. What usually happens is that a root canal has failed, or a key abutment tooth has cracked, or their periodontal condition has worsened. Any of these conditions could force a dentist to suggest that unless dental implants are placed in strategic areas, complete (removable) dentures will be needed. For most people, this step is too horrific to contemplate, let alone experience. But with the success of dental implants, complete (removable) dentures can be avoided with proper planning.

If I lost teeth due to periodontal disease, can I still have dental implants?

Definitely. Most patients present with adequate amounts of bone for dental implants. In some instances, however, more bone is needed before implants can be placed. There are predictable procedures to graft and regenerate the amount of bone needed for dental implants. Once sufficient amounts of new bone have been regenerated, enough dental implants can be placed to support a new dental prostheses.

But still, each mouth is different. How do you know I have enough bone for dental implants?

Dental x-rays and clinical exams help determine if enough bone exists to place the dental implants. Sometimes, in conjunction with a clinical examination, the dentist feels comfortable in proceeding with the placement of a dental implant. Often, though, more information is needed before making that determination.

Dental CAT scans provide the most accurate information as to how much bone is present in a jaw. Unlike dental x-rays which are two dimensional, CAT scans view the jaw in three dimensions. This gives us a bird’s eye view of what’s "inside" the jaw. The best way to understand the difference between a conventional dental x-ray and a CAT scan, is to picture a hero sandwich. Picture the top piece of bread, all the deli meats and different cheeses, and the bottom bread. Now picture the sandwich sitting on a plate. A dental x-ray would be a flattened picture of the sandwich while a CAT scan would be a three-dimensional virtual reality picture that lets us explore each area of the sandwich, from top-to-bottom and left-to-right. We would know how thick each piece of meat was, and where the cheese was located. Although you couldn’t eat it, using a CAT scan would be like holding it in your hand. That’s the kind of information the CAT gives the surgeon placing the dental implants.

Are there any dangers that I should be worried about, when having implants placed?

Yes. The single greatest concern is for the mandible (the lower jaw). When implants are needed toward the back of the jaw - in the premolar and molar areas - there is a risk of injury to the mandibular nerve. This nerve runs through the length of the mandible starting from behind the last tooth and exiting just behind the canine (or eye tooth), in the premolar area.

How can I make certain the mandibular nerve is not in the way in my case?

X-rays, often including a dental CAT scan, help visualize the course of the mandibular nerve. While the risk of injury to the nerve exits, it is very small and seldom occurs.

Are there other anatomic areas of common concern when having implants placed?

Yes, the maxillary sinus. This is the large cavity in the area above the maxillary (upper) molars. It sits under the eyes, behind the cheekbones, and to the right and left of the nose. It’s the space that fills with mucous when we have a cold. The reason the maxillary sinus is a concern during implant placement is that it is hollow. If it’s hollow, it can’t support anything. Imagine being able to place a pencil through an empty egg. Once the point is on the inside, the thin eggshell wall offers no support to hold the pencil rigid. The pencil will move. The same happens with an implant.

Is there a way to grow more bone in the sinus so I can have an implant?

Yes. The procedure to grow more bone in the maxillary sinus is called a sinus lift. Placing a bone graft in this area is not difficult to do, and yields excellent results. Once enough bone has grown, implants can be placed in an area that years ago, was deemed as an impossible site for dental implants.

Besides the mandibular nerve and the maxillary sinus, what else do I have to worry about when having dental implants placed?

Sometimes the bone is too narrow to hold an implant. In these cases, there are a variety of ways we can increase the width of the bone. This technique is called a ridge augmentation. Depending on the need, ridge augmentations are performed months before placing implants or at the same time the implants are placed.

The bottom line is that regardless of the amount of available bone, techniques exist to place implants in nearly all difficult spots. Sometimes it takes a team of surgeons to accomplish the task, and Park Avenue Periodontal Associates has assembled a team of experienced surgeons that can meet the most complicated of challenges.

What about infections from dental implant surgery?

Though rare, infections do occur. With regard to the dental literature, the verdict is not in as to whether every implant surgery should be covered with antibiotic therapy. In fact, the weight of evidence is against routine antibiotic coverage. However, the final decision in using antibiotics rests with each operator and their patients.

Can an implant be rejected?

Yes. Implants can be rejected, but not in the way we know "rejection" can occur in organ transplants, like with kidneys and hearts. We know dental implants are bio-compatible. There are no known allergic reactions to commercially-pure, titanium implants. which are the most prevalent kind used today. But failures do occur.

The failures we see in dental implants can be explained more in theory, than in fact. For instance, bacteria can contaminate implants. When this happens, an infection might cause the implant to be lost. Naturally, great efforts are taken to insure sterile conditions during implant procedures, from the way the implants are packaged to the hygienic conditions in the operating room.

But a curious fact exists: when an individual has many implants placed, why does only one fail, for example, and all the others "take?" What was different about the one that failed? Probably nothing. What we have come to believe is that the single greatest cause for dental implant failure is that bacteria are already in the jaw bone "before" the implants are placed. The implant passes through this bacteria-laden bone, like smashing through a bees’ nest, and that the seeds of implant failure have been sent into high gear. When this happens, it could take a week or a month, or even half a year, before the implant fails.

Apart from the potential pitfalls, how long does it take for the implants to "work?"

Though it can vary for specific reasons, the general rule of thumb is that implants placed in the mandible (lower jaw) heal in 3-4 months, while the maxilla (upper jaw) takes 6-7 months. Augmenting the bone, performing sinus lifts, needing jaw reconstruction, etc., will lengthen healing periods. Remember, healing times are related to human biology. Healing can not be made to go any quicker than how we were intended to heal.

Is there a second surgical stage when getting implants?

Yes. The first stage is when the implants are placed in the jaw and the bone "attaches" or integrates to the implants. In a manner of speaking, the implant becomes part of your body. Months later, the surgeon performs a second procedure to expose the implant and place a "healing abutment" on it. Soon after this is done, the dentist can begin making the desired restoration.

With all the things to worry about, how successful are implants?

Maybe this should have been the first question. But we feel strongly that the public should understand everything there is to know about implants. Implants placed by most periodontists and dental surgeons today, have a high degree of success. In fact, they are close to 95% successful in the mandible (lower jaw) and 90% successful in the maxilla (upper jaw). These percentages may vary slightly from surgeon to surgeon and among implant types, but as a rule, titanium implant dental fixtures are predictably successful.

When an implant fails, can another be placed in the same spot?

Usually, yes. We often don’t understand why an implant fails. When it does, the implant is removed. If conditions are right, the site is prepared for another dental implant. Sometimes this can be done at the time the implant is removed. Other times, the surgeon feels it is better to try again only after a prescribed healing period. Regardless of when an implant is placed in the site of a failure, it meets with a high degree of success.

For more information about dental implants, make an appointment with your dentist or contact the American Academy of Periodontology at 1-800-282-4867 or the Academy of Osseointegration at 1-800-621-0387.

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