Planning for correct implant placement Leave a comment

In Part one we have discussed the importance of understanding what is below the surface in our chosen sites. The use of known diameter ball bearings (5mm.) should be used to identify any problems of bone profile and to accurately measure the potential distortion of radiographic imaging. The technician from the model and with the information of the x-ray images can now identify emergence profiling and any other difficulties likely to arise.

You really should have a really good indication of bone and vital structures in the relevant sites targeted for implant placement.

Template construction is generally carried out using vacuum forming and clear Polyester foil of about 2.00mm thick which can be adapted to fit well on the model duplicating the wax-up and can incorporate drill guide sleeves,  ball-bearings, radio-opaque markers Barium or Kaffir D, or any other guides and markers thought useful for assessing the surgical sites. In extended edentulous areas it is sometimes wise to incorporate guides for alternative sites in case of problems during surgery. Its better the operator moves a whole tooth rather than just a little bit!

With fully edentulous drill guides it may be necessary to provide some holes through the foil to allow screw fixation into the Tuberosity or the Palatal or any suitable remote bony area to hold the guide steady during surgery.

Use of sealed black marks help to focus the operator on the target area  and the desired alignment. Black ink covered with a light cured varnish works well.

It is important that the surgical guide is suitably shaped to provide a three dimensional reminder of the long axis and insertion position of the fixture which is essential during the surgical process. With several instruments such as cheek retractors, a hand piece and potentially various soft tissue clamps it is quite a congested area and a clear reminder to the operating surgeon of the selected site is very useful.

Tooth roots are sometimes overlooked in the quest for good bone sites  and can be damaged, causing the need for endodontics or tooth loss. Not so in this case but always check X-rays for root alignment when teeth are adjacent to proposed site.

You cannot check or measure too much the following case  demonstrates good careful measurement and placement in a tight situation. Somecases may require an ongoing technical interaction such as the case shown below where the soft tissue profile was not aligned with the gingival margin of the adjacent tooth in the anterior aesthetically sensitive area. Accurate placement with bone augmentation helped to restore the buccal contour and was followed by a careful re-shaping of the gingival margin, using modified provisional crowns. Placement to the finished crown took 16 months, because of the thick biotype tissue and achieved what the patient wanted a tooth just like the one she had lost.