Perbedaan Laju Korosi pada Kawat Nikel Titanium antara Perendaman di dalam Saliva Buatan dan Ekstrak Daun Jambu Biji (Psidium Guajava L.) 100 ppm selama 10, 20, dan 30 Hari

Abstract

Nickel titanium wire is commonly used in dentistry due to its superelasticity, high tensile strength, and shape memory effect. However, in the oral cavity, this wire is susceptible to corrosion due to changes in temperature, pH, enzymes, and aggressive ions, which can reduce its strength and effectiveness, and pose risks of allergy or toxicity. One way to prevent this is by using natural inhibitors such as guava leaf (Psidium guajava L.) extract, which contains antioxidants like tannins and flavonoids. This study aimed to determine the difference in corrosion rates of nickel-titanium wire after immersion in artificial saliva and guava leaf extract (Psidium guajava L.) at a concentration of 100 ppm, and to evaluate the effect of different immersion durations of 10, 20, and 30 days. This research was a laboratory experimental study using a post-test only group design. The samples were nickel titanium wires with a diameter of 0,016 inches and a length of 5 cm. A total of 36 specimens (n = 6) were divided into 6 groups: immersion in artificial saliva and 100 ppm guava leaf extract for 10, 20, and 30 days, respectively. The corrosion rate was measured using the weight loss method. The mean and standard deviation of the corrosion rate values for groups I to VI were respectively 0,3489±0,0022 mpy, 0,4627±0,1402 mpy, 0,5049±0,0964 mpy, 0,3479±0,0016 mpy, 0,1747±0,0009 mpy, and 0,1165±0,0005 mpy. The Two-Way ANOVA test showed a significant difference in corrosion rates based on immersion solution, with p-value = 0,000 (p < 0,05). However, no significant difference was found based on immersion duration, with p-value = 0,387 (p > 0,05). Post Hoc Tukey HSD results showed no significant difference between Group I and IV (p = 1,000), but significant difference between Group II and V (p = 0.000) and Group III and VI (p = 0.000). In conclusion, immersion of nickel titanium wires in guava leaf extract was proven effective in reducing corrosion rates.