Dental implants come in many various forms. There are subperiosteal implants, ramus frames, blades, and root form implants. A subperiosteal implant is used for areas where the bone is not sufficient to accommodate root form implants. Subperiosteal implants are also used in shrunken lower jaws. The ramus frame and blade implants are mostly used in the lower back jaw when the patient is not an ideal candidate for advanced bone grafting-techniques, or the doctor is proficient with this procedure and offers it as an option. The most common type of implants used most of the time are root-form implants that mimic the tooth’s root. The reasons given in this chapter are addressed primarily to the root form implant.
The implant consists of a titanium alloy that is biocompatible to the bone and encourages the bone to form around it, holding it in place. The healing process is referred to as osteointegration.
Once the implant becomes osteointegrated, it helps to preserve alveolar bone. Approximately 60 percent of the bone in your jaws grew in response to the erupting teeth. When a tooth is extracted, you go through a process of losing bone in that area that can last a lifetime. An implant helps to preserve this bone structure by slowing down the shrinkage. It also helps to prevent malocclusion. When you lose a back tooth, you set up shifting in the other teeth. Teeth adjacent tend to move into space, and the teeth opposing drift up or down into the newly formed space. Some spaces become food traps and contribute to bad breath and periodontal disease.
Implants can slow facial atrophy- shrinkage which occurs in facial muscles when they are not adequately exercised. Roughly 150 newtons of force are applied on normally functioning back teeth, while only 50 newtons are applied on the front teeth. This force keeps the facial muscles toned and maintains our looks. If missing teeth are replaced with implants, this force is restored, and good facial muscle tone is preserved. Additionally, the ability to chew correctly vastly improves the digestion process.
Teeth are more efficient at chewing than dentures, sometimes two or three times more. There is an increased risk of aspiration of food if you have false teeth. Aspiration of food is one of the causes of death in the elderly that hardly gets mentioned, except in CPR courses. To keep false teeth more stable, many denture users will place denture adhesive inside their dentures to help keep them in place. In America, about $148 million is spent on denture adhesives every year.
Complete lower dentures usually move about ten to twelve millimeters during chewing and contribute to the need to chew softer foods that may be less nutritious. Many denture wearers develop anti-social tendencies because of their limited ability to chew a wide variety of foods. Many are unwilling or are uncomfortable when they go out for a meal.
Dental implants will stabilize dentures, crowns, and bridges and allow for more efficient and confident chewing.
Many general dentists in the United States of America do not surgically place implants, although many advertise one of their services to be dental implants. What they mean is they will plan and restore your implant after a specialist surgically placed the implant. When I did it this way twenty years ago, the disadvantage is that if the patient had a problem with the implant, they did not have a direct recourse with one dentist. A concern for the patient is when the restoring doctor and the specialist disagree on who should take responsibility for defective materials or accidental damage to the implant. I have found that most good dental teams are willing to help the patient restore their dentition by redoing the work at a reduced fee.
Note: The patient’s responsibility is to keep the information on the size and make of the implant if the patient relocates or their dentist(s) retire, leave the practice, or change locations.
In the long run, implants are the most cost-effective and efficient option. Some patients choose bridgework to restore dentition because they lack the bone needed for an implant or think this is a less costly option. However, when a dentist prepares one tooth for a crown,’ the chances of needing a root canal is about 3-5% in five years. When at least two teeth are prepared for a three-unit bridge, it increases the odds of needing a root canal over the next five years from 3 percent to about 15 percent. The additional cost and the possibility of needing to redo your bridge after root canal treatment could end up costing you more than you thought you were saving over the cost of doing an implant. Cost is measured in money, but more costly is the inconvenience and time away from your other activities.
Did Grandma die early because she did not have implants?
In 1999 my grandmother passed away at the age of seventy-nine on the way to work. She was a firm believer that If you are not sick, you should have a job. She also had a great sense of adventure and often accompanied me on my mission dental trips or visiting another state or country. Although we had arranged for her to live with my mom and dad, she insisted on turning her key in her door.
Like many those born in the 1920s, Grandma got her dentures by the time she was forty years old, and like a lot of people, she did not like her bottom denture because it had no suction. I was not insistent on her having implants because she wanted to save her money to support her independence. In retrospect, this might not have been the best long-term decision because not having implants meant she could not crush her food correctly to receive the best nutrition. Studies show that dentures are about 30 percent efficient at crushing food, implant-supported dentures around 70 percent, and natural teeth around 90 percent.
Grandma complained about the loss of appetite, stomach pains, and irregular bowel movements. She had a medication that needed to be taken with meals to prevent further stomach irritation. On that fateful morning, her lack of appetite meant she did not eat to take her medication, and her increased blood pressure led to a stroke from which she did not regain consciousness.
I miss my grandmother and wish I could have done more for her. I have committed myself and my practice to promoting the benefits of having dental implants because I think it can make a difference in people’s lives. No amount of money saved was able to keep Grandma with us for additional years, but money invested correctly in making sure she could eat more than soups and mush might have given me additional years with her.
If you are missing some teeth and your dentist suggests implants, you should consider it a good option. Listen with an open mind. My Grandma would have wanted me to give you the option of implants, and I hope you agree.
Evaluating the Bone
As soon as a tooth is extracted, blood forms a clot in the socket, and new bone cells migrate into the socket area, accompanied by immune cells and cells that form supporting tissues. Remodeling leads to the formation of new hard and soft tissue.
At initial healing, the most significant amount of bone loss occurs at the extraction site, and then bone-loss slows but continues gradually over the years. The jawbone is composed of alveolar and base bone. Alveolar bone forms in response to the erupting teeth and starts to go away when the tooth is lost. Base bone provides the foundation on which the alveolar bone develops.
When we look at the series of pictures of an edentulous jawbone (a jawbone without teeth) over time, we notice that bone loss progresses after losing a tooth and can be accelerated when pressure is placed on the tissue by wearing a denture. We recommend that implants be placed, preferably after the extraction sockets are grafted.
People wearing any type of denture should be evaluated for implants. The national standard of care recommends that if you wear a complete lower denture, you should have at least two implants for lateral stabilization and more, if possible, for bone preservation.
People are living longer, and they will need to preserve their oral structures longer. The loss of even one strategic tooth could make for long and miserable golden years. After all, what are the golden years like without the ability to chew, digest, and receive proper nutrition
The same principle of implanting new teeth for accident victims or people born with congenitally missing teeth applies. Congenitally missing teeth is a condition where the patient has fewer than a full complement of teeth. With recent advancements in implants, it is getting easier to find an implant to replace the missing teeth.
Any implant with a diameter less than three millimeters is considered a mini-implant. An implant needs to be surrounded by bone if it is to have the best chance of surviving over a long time. Historically, many implants were small because patients had lost bone due to extractions and/or wearing fixed or removable dentures.
As the ability to grow (graft ) new bone has increased, the need for smaller implants may decrease. Initially, smaller implants were considered temporary implants to stabilize temporary teeth until the larger implants could integrate with the bone. The mini-implants were then removed, and new dentures were attached to the larger implants.
Today the technology for mini-implants is so good. We are finding that you can place the implant and, on the same day, attach the patient denture crown or bridge and have a high degree of success. Several years ago, I started to use the best of both worlds. I would place mini-implants while I placed standard implants and attached the denture to the minis while letting the larger implants integrate. In many of the cases we completed, we found that the minis’ aggressive threads that allowed you to use them right away, along with the latest technology and surfaces, made it difficult to remove the minis, so we incorporated them into the final prostheses (dentures).
Suppose a patient had a well-fitting lower denture that moved during chewing and did not want to wait four to six months until their implants integrated. In that case, they could have an initial evaluation and the necessary diagnostic X-rays and/or CT scan so they could be sized based on the remaining jawbone for implants. On the day of the surgery, they could be pretty confident that they would leave with an implanted denture with some degree of stability.
The Sterngold Company, a longtime manufacturer of attachments for dentures and crowns, came up with their version using mini-implants with conventional implants adapted to work with their ERA (Extra-coronal Resilient Attachment) system that allows the prosthesis a small range of movement and enhances their longevity. A rigid attachment puts a lot more force on the implants than a resilient attachment, and replacing the resilient part of the attachment is an advantage of the ERA system.
The Zimmer dental company has since bought this system. Implant Direct also manufactures a similar system that already has the attachment for the popular locator attachment.
If you could see a series of models of the lower jawbone just before and after teeth were lost, you would see a consistent pattern. Initially, the jawbone is at its maximum height and width and supports the patient’s facial features very well.
When a tooth is extracted, the alveolar bone that grew in response to the erupting tooth starts to shrink also. When the first denture is made, it is usually the best, because most of the alveolar bone is there for support; however, as bone loss continues, the denture sinks further into the soft tissue, and the height of the lower face contracts, giving the patient an aged appearance. The next denture should be made larger to compensate for the shrinking bone. But when the dentist does this, the patient usually complains because they slowly adapted to the first denture over time.
At that point, the dentist usually cuts back the new denture so it could feel like the first denture, except it does not feel as secure because some of the bone was lost. This bone loss continues until the jawbone’s nerve is close to the surface and causes the denture wearer discomfort.
At that point, the patient usually suffers from one denture after another, looking for a dentist who could give them the feel of their first denture. The way to slow this bone loss and aged look are to place socket grafts and/or implants as soon after extraction as is possible because alveolar bone stays around implants as if it was the root of a tooth. In effect, implants only help to retain dentures but help to maintain as well.
What Are Combination Cases
Our office prides itself in our ability to take care of multiple problems in a reasonable period, with or without sedation. Over the last few years, we had several cases that involved sinus surgery. With our current technologies, we can assess the amount of bone in the upper jaw before we encounter the sinus membrane. The sinus membrane is very forgiving and can repair itself in six weeks. If there is enough bone, seven millimeters or more, we can use blunt instruments to lift the membrane-like a blanket and insert bone grafting before placing the implant. If the amount of bone left is seven millimeters or less, I may elect a two-stage technique.
In the two-stage technique, bone is grafted below the sinus by displacing the membrane upward through a small hole made in the bone’s side. A collagen liner then protects the membrane, and a bone graft is packed, leading to a new bone growth of ten to twenty millimeters. Six months later, implants of varying lengths are placed and allowed to integrate as the grafted bone continues to mature.
After integration of the implants, implant-supported teeth are placed. The patient does not go without teeth because they wear a transitional prosthesis (temporary dentures or bridges) while waiting on the body to heal. We use several implant systems in our office, depending on the results we are trying to achieve. Sometimes we have to do extractions, bone graft s, root canals, fillings, or gum treatments; place implants or place transitional appliances all during the same visit. If the case warrants it, we can use mini-implants to hold initial devices securely until the long-term implants heal. A lot of prior planning goes into providing these treatments for combination cases.
Some patients who live a long distance from the office or even in another state can have a CT scan made, and the results emailed to us to do the virtual surgery and have all the supplies needed to perform the procedures before they arrive at our office.