Initial Site Screening
If the patient is interested in the prosthodontic implant option for a missing
tooth replacement, it is helpful to early on be able to easily determine if the
B/L (P) crestal bone volume is acceptable for a correct implant placement.
It is well accepted that a minimum of 1.5mm of bone should surround the neck, and
body of the implant diameter. Less than this can result in fenistration and implant
loss. This is primarily due to inadequate seed bone and blood supply.
With this in mind how can we know this without exposing the crestal ridge bone?
Very simply as follows:
Example 1
-
Caliper (i.e. Boley gauge) the B/L (P) ridge width approximately 5mm apical from the tissue covered crest.
Example: 11.5mm Boley gauge width
-
Next determine the soft tissue thickness on the buccal and lingual (palatal) aspects of this ridge at the same level of the caliper measurement.
Example: 2mm thickness on buccal, 2.5mm thickness on lingual
-
Now add the two measurements and subtract their total from the caliper measurement.
Example: 2 + 2.5 = 4.5mm and 11.5 - 4.5 = 7mm
-
For a bicuspid replacement implant this amount of B/L bone volume will nicely suffice for a 4.0 diameter implant but would be borderline for a
4.5 diameter implant with a molar prosthetic.
This initial qualifying screening is thus very helpful in quickly determining the physical
acceptability of the B/L bone volume present in the crestal region, which in-turn gives
information as to a correct sized implant of a particular function. It can be seen then
that tissue thickness is important.
The Model-Tomographic™ however is the ultimate case selection aid when it comes to implant
diameter and placement direction. And allows construction of the 3D drill guide stent but
nevertheless this quick screening protocol definitely has its place in saving time, money
and markedly lowers risk of deficient osseointegration.
Example 2
A different example in graphic form. A proposed #7 site:
|
