Frequently Asked
Questions
This page is designed to
answer frequent questions that come up from patients or visitors of this site and is
frequently updated. So, please feel free to submit your questions to the e-mail address
below.
Q— What do dental implants offer
over conventional dental treatment?
A. Increase in bone
anchored support:
When a tooth is lost it is best
to replace it with a non-removable replacement as soon as possible. For the replacement of
a single tooth, a conventional Bridge is often
very satisfactory. However when more than one tooth needs to be replaced, the problem of
decreased support enters the picture, in conjunction with decreased chewing efficiency.
The Bridge will replace the missing teeth, however, due
to the increased loss of root support, it will not restore the chewing efficiency, on the
contrary, when the patient is trying to apply the same force onto the Bridge, the abutment teeth may suffer biomechanic
overload. Bone anchored fixtures (implants) will compensate to a great degree for the lost
root support and thus restoring chewing efficiency to a greater degree.
As a comparison, a patient with
all teeth in place will have 100 percent chewing efficiency. If the very same patient lost
all of his or her teeth and was provided with a properly fitted upper and lower denture on
an adequate ridge, the chewing efficiency would only be between fifteen and eighteen
percent. With bone anchored implants and a fixed Prosthesis
that same person may recover around 85 percent of his or her original chewing efficiency.
B. Prevent bone
resorption:
There is a strong relationship
between teeth in function and preservation of alveolar bone. If a person maintains his or
her teeth well periodontally and is free of any systemic diseases, the alveolar- or ridge
bone will be maintained as a response to the load it is subjected to during normal
function (chewing). However, when teeth are lost, the alveolar bone will undergo atrophy
in the areas where teeth are missing as a response to the lack of direct load. Again, a Bridge will only supply a marginal amount of load to the
underlying bone and even less so a Removable Partial
Denture or a Full Denture. A bone anchored fixture
or implant, on the other hand, will transfer the chewing force directly to the surrounding
bone and maintain its volume, if the crowns on top of the implants are properly adjusted
to a correct bite. The Bonegrafting section shows several
images of the kind of bone resorption patterns that are frequently encountered as a result
of tooth loss.
Below to the left, you can see an
image of how the bone has resorbed in response to loss of an incisor. Below to the right
you can see how the defect was restored through a Bonegrafting
procedure and placement of an implant (the blue line will aid you in gauging the amount of
resorption shown in the left image and the amount of volume re-gained in the right image):
C. Maintain healthy teeth:
Even in some single tooth
situations an implant can offer advantages. If teeth adjacent to a toothless area are
perfectly healthy and have no fillings, it would be to the patients advantage to leave
them unprepared and deal with the replacement prosthesis as a separate unit, instead of a Bridge, which requires the two adjacent teeth to be
shaven
down for. Furthermore, especially in the front part of the mouth (the Smile Line), a
single tooth implant restoration may offer better long term esthetics, due to the
prevention of bone resorption (such as shown in the above image) in the toothless site.
Q— How successful are implants?
There are many variables to be
considered when placing implants. First, the patient must be in good health. Systemic
problems such as uncontrolled diabetes or habits such as heavy smoking will translate into
inconsistent healing and could complicate the procedure. Second, a proper diagnosis must
be made and the proper implant placement procedure must be selected for the individual
patient in reference to the final prosthetic result. Third, the implant must be treated
properly by the patient and the doctor. Under favorable conditions, success rates vary
from 90% to 98% across most published studies.
Q— Is age a deterrent to implant
treatment?
Age is not a deterrent to implant
treatment. Health is the determining factor. Many people seventy and eighty years of age
are better surgical candidates than someone who is years younger with physical or systemic
complications. There is really no preferred age for a hip replacement or a coronary artery
bypass. As long as a person is in good health and is important to someone, including him-
or herself, one should strive to improve the quality of one’s life.
Q— Is Osteoporosis a deterrent to
dental implants?
The success of Osseointegration depends in part on the state of the host
bed. Concerns have therefore been raised about osteoporosis, a condition believed to be
associated with a decrease in bone quality and quantity. However, the orthopedic
literature indicates that osteoporotic fractures heal readily and that the level of bone
mass and estimates of the parameters associated with bone remodeling present considerable
overlap between patients with osteoporosis and control subjects. It also appears that
osteoporosis, as diagnosed at one particular site of the skeleton, is not necessarily seen
at another distant site. Although the prevalence of osteoporosis increases among the
elderly and after menopause, the results of several studies indicate that implant failure
rate is not correlated with osteoporosis in patients. A review of the literature and of
results of a series of patients treated does not provide a compelling theoretical or
practical basis to expect osteoporosis to be a risk factor for osseointegrated dental
implants.
Q— How many implants do I need?
This question is not always easy
to answer. A general rule of thumb is to replace each tooth with one implant, however
sometimes we are not that lucky, because there are anatomical or financial limitations, we
have to compromise somewhat. We try to get similar types of anchorage out of
implants, as we had in natural teeth. In order to achieve that, we need to consider the
total surface area of a natural root that is embedded in bone and compare that to the
surface area of an implant. The two images below illustrate that somewhat.
 |
|
 |
Above you can see the size
difference of a root from a molar tooth and a typical 3.75 mm diameter implant. |
|
This image shows a 3.75mm
diameter implant inside the socket of a premolar tooth. Notice the discrepancy between the
implant and the bony wall of the socket. |
Your back teeth have two or
three roots having a total average anchorage area of 450 mm² to 533 mm² in bone whereas
a typical implant of 3.75 mm diameter consists of a single root with a surface
area of 72 mm² to 256 mm², depending on its length. Therefore, the tooth can dissipate
biting forces (as much as 1600 lbs) efficiently, whereas the implant may be less capable
of doing so. Furthermore, the crown of a back tooth (molar) has a surface area of
approximately 100 mm², whereas the cross-sectional area of a 3.75-mm diameter implant is
only 10.95 mm². Thus, the chewing forces, when exerted at an angle in relation to the
implant post, will create too much stress on the implant bending and torquing vectors.
Luckily today the implant companies have responded with wider-diameter implants (5mm-6mm)
which improves the discrepancy of the figures above somewhat. So, in view of the above
discussion, we usually recommend at least one implant for each tooth lost, however this
can change depending on the individual situation and what type of restoration the patient
wants.
For instance, if the patient has
no teeth and wants basically only his or her lower denture to be more stable, but
essentially keep the lower denture as the prosthesis of choice, we might get away with
only two implants. Generally, the more implants placed, the more stable the prosthesis and
the better the long-term prognosis the implants will be.
Q— Does it hurt to have dental
implants placed?
This question is difficult to
answer, in view of people’s different pain tolerance levels and the complexity of the
procedure itself. For a straightforward situation (single tooth implant without any Bone Grafting), most patients reported very mild
post-operative pain. Almost all patients considered a simple extraction a lot more painful
post-operatively, than an implant placement. During the surgery, there should be no pain
due to the prior administration of local anesthetic agents.
Q— What about the cost of dental
implants?
Implant procedures, which vary in
complexity and extent, depending on the patient’s dental condition and requirements,
can involve a significant investment. A survey of 350 patients after completion of their
implant treatment revealed that not only was it worth the investment, but they would
happily do it again.
Oral rehabilitation involving
dental implants is generally considered an expensive procedure, especially as the number
of implants increases. However, the benefit of having chewing efficiency restored,
preserving alveolar bone and not having to prepare sometimes-healthy teeth for a Bridge should be well worth the expense.
Q— Are implants covered by
insurances?
Generally, the great majority of
dental or medical insurances do not cover oral implants yet, although last year there were
isolated insurances that covered certain modalities of implant reconstruction. Sometimes,
certain medical insurances cover a portion of the surgical cost.
One has to understand, however,
that most insurances do not necessarily look out for the patients best interest, but
rather try to restore the patient’s health in an acceptable manner. Now this
term may be very vague, but usually does not cover state-of-the-art medicine or
dentistry.
The annual insurance benefit
amount or whether a procedure is fully covered or not are very poor motivating factors for
restoring one’s health. Our health is the only precious thing we have and should
deserve nothing less than the best that medical and dental sciences have to offer.
