How Many Implants Do You Need for an Implant Fixed Bridge or Implant Denture?

For patients that have failing teeth or a floppy denture, dental implants are a great option to get their smile and their life back. Once teeth are removed, there are many different treatment options to consider and many of our patients are asking us “how many implants do I need for my case?”

There are many different options for our patients that need a full arch of implants and this can vary from 2 implants all the way up to 8 implants at the most. The amount of implants needed for a full arch of teeth depends on a few factors:

• Which jaw is being treated
• The amount of bone available
• The patient’s musculature and chewing system
• The design of the prosthesis (fixed or removable)

Are your implants on the upper or lower jaw?

The upper and lower jaws of the human body are very different. The upper jaw bone is usually much softer. Imagine placing a screw into the styrofoam. The upper jaw bone can be as soft as styrofoam or a very soft wood. Because of this, more implants usually need to be placed for a stable, long-term result. The upper jaw also has large sinuses which are air-filled spaces in the bone where implants cannot be placed. When teeth are lost, these sinuses expand making it more difficult to place implants. When treating patients who need a full arch of teeth, we try to avoid sinus surgery (such as a “sinus lift”) and place our implants around the sinus. Because of the softer bone in the upper jaw, the minimum amount of implants that can be placed for a full set of teeth are 4 implants, regardless if the final prosthesis if fixed or removable. You cannot do anything on 2-3 implants in the upper jaw or things are more likely to fail. For a removable “click-on” set of teeth, 4 implants must be placed. For a fixed option, 4 implants are the minimum amount of implants that can be placed. If the bone is extra soft, the bone is short or thin, or the patient produces a large amount of force, more implants must be placed. This can be from 4-8 implants. The maximum amount of implant needed in the upper jaw would be 8 implants.

The lower jaw, on the other hand, usually has very dense bone, like oak wood. Because of this, you can place fewer implants often times and still get a stable result. A problem specific to the lower jaw is that there are two large nerves which we must avoid. Often times, when patients have missing back teeth for many years, the nerve makes it difficult to place implants in the posterior area. This is why we try to place most of our implants in the front part of the mouth. Because of the dense bone of the lower jaw, you can place fewer implants at times. For example, if you want a removable option, you can place as little as 2 implants in the front of the lower jaw and have something that snaps in and out. Although this will still rock a little bit when you chew, it is much more stable than a denture!

How much bone do you have in your jaws?

Just like a signpost or the foundation of a house, the deeper into the soil the posts go, the more stable the sign or house will be. Dental implants are the same! We always want to put in wider, longer implants to have the teeth be more stable. If we have plenty of bone, we can place nice long implants and can place less for this reason. So when bone is abundant, we can place 4 implants in the upper jaw and 4 implants in the lower jaw for a fixed option. When the bone is more limited, we have to place more implants because the ones we can place, are shorter. When more implants are placed, this can increase the costs of the procedure for the patients due to implant fees and lab fees for more components.

Do you grind your teeth or have large chewing muscles?

The amount of implants that must be placed also depends on the chewing system of the patient. Just like tires on your car, an off-road vehicle requires much larger, tougher tires where a day to day car on the street doesn’t need very tough tires. This is the same for dental implants. If you have very strong muscles in your jaw and grind your teeth, you may need a few more implants to over-engineer your prosthesis to reduce the chances of breaking anything whereas an older patient who doesn’t grind his/her teeth, and is smaller in stature, would require fewer implants.

Do you want something fixed or removable?

Different patients want different things. Some prefer something fixed that looks and feels like natural teeth but can be a little more challenging to clean while others are used to something that comes in and out and is easier to be cleaned. On the lower jaw, a removable option can have as little as two implants for something to snap in and out while fixed options need a minimum of 4 and can go up to as many as 8 implants. In the upper jaw, the minimum amount of implants needed for fixed or removable is 4 implants because of the bone being softer in the upper jaw. The minimum for the upper jaw is 4 implants and the maximum is usually around 8 implants.

To summarize the above information:

• Upper Jaw Removable Option: 4+ implants
• Upper Jaw Fixed Option: 4-8 implants
• Lower Jaw Removable Option: 2-4 implants
• Lower Jaw Fixed Option: 4-8 implants