Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Napetschnig, M.
In vivo investigation of corrosion kinetics and corrosion reactions between co-implanted durable materials and bioresorbable magnesium implants
Zahnmedizin; [ Diplomarbeit ] Medizinische Universität Graz; 2022. pp. 72
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Herber Valentin
- Payer Michael
- Altmetrics:
- Abstract:
- Introduction: The aim of this study was to perform an in vivo investigation of the corrosion kinetics and reactions during co-implantation of durable materials such as titanium (Ti) and bioresorbable magnesium (Mg) in order to consequently evaluate and quantify their mutual influence on material properties and degradation rate. The use of biodegradable implantation materials has gained interest in recent decades in paediatric surgery and traumatology as well as in dental surgery and implantology. This is due to their positive material properties such as excellent biocompatibility and osseointegration as well as their good mechanical properties. However, co-implantation can accelerate the rate of degradation due to the different electrochemical potential of the metals and the resulting formation of a galvanic like cell. This unstable and partly unpredictable corrosion behaviour is discussed as a limiting factor for the application of bioresorbable Mg as an alternative to conventional implantation materials. Methods: During a surgical procedure, bilateral transcortical co-implantation of pins (ø= 1.4 mm, h= 6 mm) made of a Mg-based metal alloy (ZX00) and Ti-6Al-4V (titanium grade 5) occurred in the tibiae of 24 male Spraque-Dawley® (SD) rats at 5 and 10 mm. Furthermore, as a control, magnesium spaced by shams were implanted in a group of experimental animals. µCT scans of the implanted pins were taken on the day of implantation and at 4, 8 and 12 weeks post-implantation to quantify the hydrogen gas produced by corrosion and the rate of degradation and to detect changes in the implant surface and volume. A qualitative histological evaluation was also performed using methylene blue and basic fuchsin. At various times (T 0, W 4, W 8 and W 12) of the same material, statistical analysis using one-way-analysis of variance (ANOVA) was carried out. Results: We observed a moderate hydrogen gas production in all our experimental groups over the entire experimental period of twelve weeks. Only in the group with the distance of 5 mm between the co-implanted ZX00 and Ti pins did the results of our µCT analyses show a slightly higher H2 gas production compared to the rest of the experimental groups. The initial increase in implant volume and surface area we observed could be attributed to the formation of the corrosion layer on the ZX00 surfaces described in the literature. The measurements of longitudinal bone growth also showed a homogeneous increase in all test groups. Conclusion: The results of our in vivo studies show no influence of Ti on the degradation of bioresorbable ZX00 due to galvanic corrosion up to 12 weeks after implantation. Furthermore, it could be shown that there was no impairment of longitudinal bone growth, making ZX00 a promising bioresorbable alternative in the field of paediatric surgery and orthopaedics. To estimate the degrading behaviour up to the total dissolution of ZX00 pins, however, more in vivo and clinical research must be done.