Biomedical Engineering Reference
In-Depth Information
immunological properties were good but correlated to the seat of the withdrawal and to the
type of bone processing (
5-7-8-9)
. The Demineralized Bone Matrix can be easily extracted
with 0.5 or 0.6 NHCL (
10-11)
from the allograft bone so as to obtain an increase in the bone-inductive capacities, the loss
of the immunological power and an increase in his supplementary effectiveness (
12)
. One of
the limits of the Demineralized Bone Matrix is his malleable consistency which makes him
suitable for the bony filling most than to the bony replacement, above all in districts of the
face that is not subject to the traction of the soft tissues (
13)
. Everybody notice the porous
polyethylene, used for the reconstruction of the hard tissues of the face; This material
presents bio-compatibility with the human organism and easy malleability (
14)
. This
includes that the surgical time are considerably reduced and the surgical procedure are not
much invasive. One of the advantages of this material is his property to restore big bony
deficits, contributing to give volume to the absent structures . It is fixed by screws, which
contribute to the maintenance of a fixes position in the time, as it is also taken back in
literature (
15).
His utilization can be corollary of the orthognathic surgery in the restoration
of the facial harmony or in the treatment of facial asymmetries from pathologies.Sharpen for
this big variety of applications the porous polyethylene exists in various forms concerning
the various facial places to restore: orbital margin (
15),
nasal dorsum, mandibular ramus.
The injectable filler are very commonly used for the treatment of soft alterations of the
tissues of the face; these can be of different nature and composition. Are commonly divided
in temporary and permanent; in our work take the permanent filler into consideration like
the plyacrylamide and polialkylimide. These are also defined of the "hidrogel", for the high
water content; their use has prevalently aimed at the filling of soft tissues, whit satisfactory
results. Their principal properties are: elasticity, permeability and high bio-compatibility
with the organism. Of these we remember the polialkylimide, injective bio-material formed
by 2.5% of synthetic polymer of polyalkylimide and for 97.5% from apirogen water. Studies
have been also executed in 12 vitro and they have shown a low toxicity and cutaneous
sensibilization, following prolonged treatment. The polyacrilyamide (
16- 17)
is an injectable
bio- material, formed by 3% of reticulate polymer of polyacrylamide and 97% from not
pirogenic water. It is an hydrophilus absorbent gel, what comes infiltrated in deficit of the
soft tissue. His mechanism of action is to add volume to the soft tissues, restoring the
normal structures of the face. This bio material has an easy applicability also in different
pathologies; important is not to use in post herpetic phase. It needs several applications for
the partial absorption which can verify.
5. Results and conclusion
The study's results, based on our experience, have been more than satisfactory. The 290
treated patients, have given optimum results to a 6 year follow up. And also true that the
experience acquired during the years about the porous polyethylene is previous of 12 years
from the beginning of our study, that is happened in 2000. The justify for which in such
work we considered the patient treated from this date, is due to the fact that before we did
not have a sufficient sample of patient treated with other filling biomaterial to compare with
porous polyethylene already mentioned. In aesthetics surgery the new fillers got rich of
greater biological qualities and of easy utilization and their application has made possible
for various infectious, malformativ or post-traumatic pathologies. This comparison has been
optimum, in the perspective of a patient's better management and treatment of the deficits
