Dental implants are produced with artificial
roots made of biocompatible material (titanium)
placed in the maxilla or in the mandible.
These roots are manufactured in various
models and sizes; they can be screw-shaped,
needle-shaped and cylindrical.

Needle-shaped implants (ř1.2 mm and a few centimetres in length) and screw-shaped ones (a few millimetres longer in diameter) are screwed into the narrow hole made in the bone tissue (naturally with adequate instruments) till the required depth is reached.
Screws thus inserted fit steadily and instantly due to their external thread. Needles instead have a smooth surface and offer the same stability. However, once the roots are inserted, parts emerging from the gums must be electrically welded together.
These will be the stumps on which teeth are inserted.
Besides, the size of screw and needle implants can be changed to suit the quality of the bone tissue available.
Experience has proved that needle and screw implants applied with this method enable the patient to immediately leave the dental practice with a fixed prosthesis.

Cylindrical and conical implants
A different method involving various stages is required for cylindrical and conical implants. Implant insertion requires abundant bone tissue, which must also be adequate for large implants.
Besides, as implants are not immediately enveloped by the hole in which they are inserted, a few months wait is essential for them to fit permanently into the bone.
This period is required to reach the so-called “bone integration”. When the bone tissue available is very little, a bone-graft from parts such as chin, ribs etc. may at times be necessary and the time factor will increase in these cases.
Long and documented experience has clearly proved the advantages offered by certain methods, compared to others. However, the “Branemark method” is often used, though it is more invasive and painful. The above-mentioned methods are illustrated below.
Translated by interpres sas

CASE N.1

Figure 1 Immediate post-extraction implant with self-tapping screws. Emerging parts on which the teeth will be fitted are clearly visible

Figure 2 X-ray of screw parts fitted into the mandible.

 

CASE N.2

Figure 3 Post-extraction implant performed with needles soon after the extraction of teeth that are beyond treatment. Emerging parts visible in the picture will be electrically welded together (with a device that has been specially designed for such operations and complies with EEC regulations) to form the structure on which the artificial teeth will be fitted.

Figure 4 X-ray highlighting needle parts inserted in the mandible, as with the screws.

CONFRONTATION

Figure 5 Example of a temporary fixed prosthesis inserted soon after the implant, whether this has been performed with self-tapping screws or with Scialom needles (the final one will be aesthetically even more perfect).

Figure 6 Branemark type implants. Unlike screw or needle implants, their insertion requires the removal of cylindrical bone parts and the detachment of the entire fibrous tissue and mucous membrane of the gengivae (as per photo). After a period of two or three months, in other words when they are steadily fitted and the gengivae are completely healed, the emerging parts or better the stumps on which the teeth will be fitted will be screwed into the central hole, which is clearly visible in the picture.

CASE n.3

NEEDLE IMPLANT IN BLADE-SHAPED BONE TISSUE (A BONE TISSUE GRAPH, WHICH IS QUITE TRAUMATIZING, WAS NOT REQUIRED, AS CAN BE NOTICED IN THE FORMER PICTURE)

Needle implant sequence in an upper incisor crest - the bone is much diminished in thickness - without the need to widen it with bone graphs.

Needles inserted in diverging parts. The bone ridge is defined with a device that highlights its fineness.

All needles have been inserted.

Tying up with titanium wire and welding of emerging needle parts. Implants with a lager diameter have been fitted in the distal regions, as per the descriptions that follow.

Overall check at the end of the job highlighting larger diameter implants too: (self-tapping screws inserted where the bone tissue was thicker).

End of implant and prosthesis job.

Despite the very fine bone tissue in the incisal region (blade-shaped), the abovedescribed case did not require the surgery illustrated in this figure, in other words bone graphs from other skeletal parts (which is more traumatizing and requires more time to heal).

In this case a large amount of bone was removed from the right side of the mandible, due to surgery performed by others. A permanent prosthesis was then fitted with button connections to the residue roots that can be seen in the picture.
But this prosthesis was absolutely unstable and hence not very functional. As the patient’s age (70 years) too did not permit excessively traumatizing surgery with bone graphs, the implant and prosthesis job was completed with the aid of CAT scans and very fine needle implants, as can be noticed in picture n°2.

End of case. The good aesthetics achieved can be clearly seen. Even the fibrous tissue and mucous membrane on the right side of the patient, which is not compressed anymore by the removable prosthesis, has risen a little, hence the length of the teeth too in this region is quite acceptable (referring only to aesthetics, as functionality is excellent).

AT scan of the right mandible, the most interesting area due to its considerable reduction in bone tissue (in height).
Though these implants really have a 1.2 mm diameter, hence they are very fine, they seem to have a longer diameter in this computed tomography image probably due to technical reason.
However it is clear how needle implants are inserted first on one side and then on the other side of the mandibular nerve, wherever there is room to insert them and following the nerve’s course: in this manner they pass over it without damaging it in any way.
The small white spot, as far as it can be seen in the computed tomography image’s small dimensions, is precisely the mandibular nerve, entirely spared by the needle implants introduced.
The implant and prosthesis job was completed with the aid of CAT scans and very fine needle implants, as can be noticed in picture n°2.

Massimiliano Apolloni
Odontoiatra - Trento