**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

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

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 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

with 0.5 or 0.6 NHCL (**10-11)** 

the partial absorption which can verify.

**5. Results and conclusion** 

of the facial soft tissue: in order to choise the biomaterial as much as more suitable and-bio compatible with the host organism. To a careful evaluation of every single case, the results have not been completely uniforms; in the patients treated with polialkylimide, adverse reactions have happened: in two cases has verified a multi-capsule formations around the biomaterial , with relative capsule formation and an only case the rejection, with adverse cutaneous reaction. In particular the case of rejection has verified in subject with Hemi-facial atrophy. The phenomenon of compartimentalizzazione was verified in only two cases, it was not due to the absence of integration of the biomaterial with the organism but it was consequent to the 13 autoimmune pathology. For the subjects treated with polyacrilyamide adverse reactions have not happened; the material has shown a good integration in patients with various pathologies . This biomaterial turns out to be of easier utilization and provided with greater fluidity injection. For what concerns the patients affected with infectious pathologies like HIV, their treatment with filling biomaterial has given both recent and after 3 year distance good results; rejection events have not happened. Such patients are constantly evaluated by the infective point of view; we have experiences of biomaterial's utilization in HIV+ patients with HAART treatment which present lipodystrophy lesions . The malleability and easy application of the hydrogel, an utilization of theirs has made possible in combination to other biomateriali. The use of different biomaterials in the same patient is necessary when the deficit to fill was high and when the simple application of an only one biomaterial was turning out insufficient. The treated cases have given good results and good tolerance between the installed material. Porous polyethylene, bio-bone, Polyalkylimide, Polyacrylamide offer a good alternative in selected cases to the traditional reconstructive surgery, for the immediate results and easy way of application. A follow up of at last six years through echography and Computed Tomography exams shows their biocompatibility, stability and inactivity, The restoring of symmetry and harmony of a face can be reached through both traditional surgery and also using biomaterials, that can substitute tissues graft or osteotomy with an easy way of application, their stability and their long lasting, not last a good esthetic result.14

### **6. References**


**Part 4** 

**Prevention and Management of Biological** 

**Phenomena at Biomaterial/Cell Surfaces** 


Elena Indrizzi, MDS, Luca Maria Moricca, MD, Valentina Pellacchia, MD,

Alessandra Leonardi, MD, Sara Buonaccorsi, MD, Giuseppina Fini, MDS, PhD. The Journal of Craniofacial Surgery –Vol.19, N. 4 -July 2008
