Author(s):
1. Valentina Veselinović, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina
2. Tijana Adamovic, University of Banja Luka, School of Medicine, Dentistry Study Program, Republic of Srpska, Bosnia and Herzegovina
3. Olivera Dolić, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina
4. Radmila Arbutina, University of Banja Luka, School of Medicine, Dentistry Study Program, Republic of Srpska, Bosnia and Herzegovina
5. Nataša Knežević, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina
6. Ognjenka Janković, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina
7. Slava Sukara, University of Banja Luka, School of Medicine, Dentistry Study Program, Republic of Srpska, Bosnia and Herzegovina

Abstract:
Maxillofacial prosthetics representing a science and art of anatomical, functional, and cosmetic reconstruction by means of artificial replacement of head and neck structures that are missing or defective. Silicone elastomers are the materials most commonly used to make these prosthetics . In maxillofacial area, this materials are exposed to various ekstraoral environmental factors, that can adversely affect the mechanical and physical properties of this material. Two major problems, associated with maxillofacial prostheses, used to rehabilitate patients with oralfacial defects are: 1) the degradation of static and dynamic physical properties of elastomers, and 2) discoloration of the prostheses in a service environment. Scientific studies have found satisfactory results by incorporating different kind of nanoparticles (NPs) into maxillofacial silicone elastomers, in terms of protecting such materials from degradation. AIM: The purpose of this in vitro study was to evaluate the influence of adding ZnO nanoparticles on the surface hardness and color stability of pigmented silicone maxillofacial prosthetic elastomers. The properties tested were selected because of their important clinical significance. MATERIAL AND METHODS: Color evaluation were performed on 60 colored silicon specimens, divided into three groups: I - spaciements modified with 1% ZnO nanoparticles, II - speciement modified with 2% ZnO nanoparticles, III - control non modifed speciements. Outcomes were measured before and after accelerated aging for color changes as well as for surface hardness values. Data were analyzed by variance (ANOVA) and Tukey honest significant differences test (α=.05). RESULTS: Results showed that the presence of nanoparticles influenced the properties of the assessed groups. Modification of facial silicon by ZnO nanoparticles increasede hardness values. The highest values of surface hardness were observed for the groups with addition of 2 % ZnO NP, group without NP showed the lowest values of surface hardness. ZnoO modified specimens showed minimal or no color change, representing significant color stability after being subjected to outdoor weathering. CONCLUSION: Based on the findings of this in vitro study, the modification of maxillofacial silicon elastomer material by addition of ZnO nanoparticles can be recommended.

Key words:
maxillofacial protesis,silicon elastomers,ZnO nanoparticles,surface hardness,color stability

Thematic field:
SYMPOSIUM B - Biomaterials and nanomedicine

Date of abstract submission:
17.08.2020.

Conference:
Contemporary Materials 2020 - Savremeni materijali