Pengaruh Aktivitas Antioksidan Ekstrak Etanol Daun Afrika (Vernonia Amygdalina Del.) sebagai Inhibitor Korosi Galvanik pada Piranti Ortodonti

Abstract

Introduction: The components of fixed orthodontic appliances that play an important role in tooth movement are brackets and archwires. These two components may undergo galvanic corrosion in the oral cavity due to the contact between two different types of metal in saliva. The occurrence of corrosion cannot be prevented and is a natural phenomenon; therefore, efforts to control corrosion are necessary through the use of inhibitors such as African leaf extract. Several studies have concluded that African leaf extract contains antioxidant compounds such as flavonoids, tannins, and saponins that have the potential to function as inhibitors. Objective: To determine the effect of antioxidant activity in the ethanol extract of African leaf (Vernonia amygdalina Del.) as a galvanic corrosion inhibitor and its impact on microstructural changes in stainless steel and NiTi bracket-archwire combinations. Method: This study used a laboratory experimental design using a post-test with control group design. The samples consisted of edgewise orthodontic brackets for maxillary central incisors made of stainless steel with a 0.022 slot, and two types of orthodontic archwires made of stainless steel and NiTi with dimensions of 0.016 x 0.022 inches and a length of 3 cm, totaling 28 samples. The samples were divided into four groups: stainless steel bracket-archwire immersed in artificial saliva, stainless steel bracket-archwire immersed in ethanol extract of African leaf at a concentration of 1560 ppm, NiTi bracket-archwire immersed in artificial saliva, and NiTi bracket-archwire immersed in ethanol extract of African leaf at a concentration of 1560 ppm. All samples were incubated at 37°C for 7 days. Subsequently, examination was performed using SEM-EDX. One-way ANOVA was used for statistical analysis. Results: The results of the One-way ANOVA test showed a significance value of p < 0.05, indicating that the antioxidant activity of the ethanol extract of African leaf (Vernonia amygdalina Del.) at a concentration of 1560 ppm affected the corrosion rate of stainless steel and NiTi bracket-archwire combinations. The Post Hoc LSD test revealed significant differences among all test groups (p < 0.05). Conclusion: The ethanol extract of African leaf has antioxidant activity that functions as a galvanic corrosion inhibitor on stainless steel and NiTi bracket-archwire combinations.