CT-Guided Dental Implants
1. What is a dental implant? How would that help me?
Many people have heard of dental implants. But this is a common question. Let me explain by using an analogy.
If you are rebuilding a house that has been, say, completely damaged by a tornado, you would first check and see how solid is the foundation that is left. If the foundation is also gone, it is time to start from scratch and pour a new foundation. But for that, you need a solid ground in which to lay that foundation.
Similarly, if a tooth is too far decayed or has cracked roots, then it is time to remove that root and put a new artificial root. But first, the jaw bone in that area should be evaluated to make sure that it can reliably support an implant and a tooth supported by it.
So a dental implant is an artificial root made of surgical grade titanium. It helps support an abutment, which is an artificial tooth connected to this root. In turn, a crown which looks like a tooth, covers over the abutment.
Back to the house analogy, the implant is the foundation, the abutment is comparable to the walls that make up the house and the crown would be the roof and brick wall covering the house.
2. What are the advantages of implant supported crown compared to the older methods to replace a missing tooth?
Implant supported crowns are not the only way to replace missing teeth.
Just like in medicine, there have been amazing advances in modern dentistry.
In the olden days, if you had a bad knee or a bad hip... you will be given a walking stick! You can get by with it. That might still be OK for some people. But most would want more of a quality of life than that. I have a cousin who completely blew out her knee snow skiing. She now has an artificial knee. The surgeon told her that she should go back and ski, if she wants to. Her quality of life should not be lessened because she had an injury and now has an artificial knee.
When teeth are lost, removable false teeth (dentures, plates) can be a replacement. They can fool a lot of people a lot of the time. But the people that actually wear them can never forget what they have. Dentures can move around, food can get stuck under them and may come loose at the most embarrassing times. Many times, when these folks go out to dinner, they look through the menu and choose what they CAN eat; not what they would LIKE to eat.
Only you can decide what is good enough for you.
3. What about replacing some missing teeth; not ALL of them?
Sure. There are other options. One would be removable partial dentures. They are OK, but more similar to dentures with some of the same issues. Since they are connected to some of the remaining teeth, if the false teeth move, they can act like a crow bar and loosen the supporting natural teeth.
If there are teeth on either side of an empty area, the teeth on either side may be prepared to attach one or more fixed false teeth. They are called fixed bridges. Many people hate the idea of removing all the enamel off good teeth in this process. They also know that they can lose these supporting teeth to cavities just like other teeth.
Implant abutments are made of titanium or ceramic. So they can’t rot like real teeth can.
4. How are dental implants placed? Does it hurt?
First, I should describe how WE do it and WHY we do it this way. Then I will describe how it is most commonly done.
We start with knowing ALL the facts. Where exactly do we want the crown? This is the top, that is supported by the abutment and which in turn is attached to the foundation that is the dental implant. Then we take a CAT scan of the jaw with the location we want the crowns marked. Now we have the information about the jaw bone in exquisite 3 dimension detail. We know where the implant would need to be placed so that it is right under the crown in a straight line. Wouldn’t you want the foundation, right exactly under the house? We also know EXACTLY how soft or hard the bone is, since the CT scan allows us to measure bone density in any spot. We know EXACTLY where the nerves, sinuses, nasal cavity and blood vessels are in relation to where we want to place the implant. We get to do virtual surgery on a computer generated jaw, BEFORE the actual event.
A good builder would do core sampling of the building site FIRST. Otherwise, he may run into a spring or sinkhole when digging for the foundation.
Once all the preparatory planning is done, this data is used by software that allows guides to be made that align us every step of the way in placing the implants – where exactly to place it, how wide, how deep and in exactly what angulation. All the planning is done first before we start. Since so much planning goes into it BEFORE the surgery, the actual surgery is fast and is anti-climatic. It is done before you know it.
The guide is placed in the mouth after anesthetizing the area just like for a filling. Through the guide hole, a tissue punch is used to take a divot of tissue just large enough to accommodate the implant. Then using sleeves that are matched to each size surgical drill, the implant hole is made and enlarged gradually to planned size. The implant is screwed in to place, to proper tightness and the procedure is done.
So in this method, called “fully guided implant placement”, there is no peeling of the tissue away from the bone to take a direct look at the bone and so there is very little bleeding or pain.
I had cracked a tooth and lost it. My choice was an implant. I personally had an implant placed in this manner and went out to dinner immediately following the procedure. I did not even need to take an aspirin afterwards.
4. How are dental implants “usually” placed? (See how WE do it and WHY in the answer above)
Most commonly, dental implants are placed by oral surgeons and periodontal surgeons. Using panoramic x-rays that show the jaws in a 2 dimensional representation and with variable magnification that is dependent on how the patient was positioned on the machine. So they have to allow for some error margin and play it safe by picking an implant that may be a bit shorter and narrower than the actual space available. If the ‘guesstimate’ is wrong, there could be nerve damage leading to permanent numbness or the implant could come out the side of the jaw requiring removal.
During implant placement, the surgeon peels the tissue completely off the jaw bone under anesthesia to see the shape and contour of the bone. Then a hole is drilled where they estimate the restoring dentist might want to put teeth. During this time, the bone is felt with gloved fingers to feel that the drill is not coming out the side. Once the hole size is adequate, the implant is screwed in. The tissue flap is sutured back into place and allowed to heal.
If you ever had your impacted wisdom teeth cut out, this will be more similar to it. There is more discomfort and swelling after such a procedure, like after wisdom tooth surgery. The actual placing of the implant hardly causes these symptoms but the peeling off the tissue flap does.
5. Besides the discomfort for the patient and more healing time, do both methods end up with the same implant results? What are some other differences between the “conventional” method and the “fully guided” surgery method?
One of the most common frustrations for a restoring dentist is discovering that the implant has been placed at a different location than right under where the crown needs to be, in order to match the opposing tooth. The surgeon had placed the implant “where there is bone”. The restorative dentist would have to “make it work” since the patient has already gone through the cost and discomfort of implant surgery.
Another common problem is that the implant comes out in a different angle than the angulation of the crown. Again, the surgeon had placed the implant “where there is bone”. The dentist would have to “make it work” by attaching angled abutments. It is easy to see that it is best to have the implant perfectly line up under where the crown needs to go.
Imagine that you need a business computer IT solution. It is like buying computer hardware from one company and software from another company and hoping it will all work out. The smarter decision may be to get the whole solution from one company where there are no worries about that hardware working well with that software.
The example below illustrates the results from this “top down” approach of “fully guided implant placement” technique.