Pengaruh Lama Perendaman Kawat Ortodonti Stainless Steel dalam Ekstrak Daun Afrika terhadap Laju Korosi dan Gambaran Mikrostruktur

Abstract

Wire is an important element in the structure of fixed orthodontic appliances. One example of a material that is often used as a wire is stainless steel. Stainless steel wire has the potential for corrosion so it needs to be inhibited by the presence of inhibitors. The purpose of this study was to determine the effect of immersion time of stainless steel orthodontic wire on the corrosion rate and microstructure of the wire in artificial saliva solution, 0.2% chlorhexidine and 12.5 mg/ml African leaf extract for 14 and 21 days. This research is a laboratory experimental research with pre and post-test with control group design. The samples were stainless steel orthodontic wires from American Orthodontics with a diameter of 0.016 x 0.022 inches and a length of 3 cm as many as 30 pieces soaked in 6 groups. The samples were placed in an incubator (37oC) and then the corrosion rate was calculated using the weight loss method and the microstructural changes of stainless steel orthodontic wires were analyzed using the Scanning Electron Microscope (SEM) method. The average corrosion rate of stainless steel wire in artificial saliva for 14 and 21 days was 0.1380.126 mpy and 0.1530.003 mpy, in chlorhexidine solution was 0.3230.127 mpy and 0.3970.175, and 12.5 mg/ml African leaf extract was 0.2320.127 and 0.0920.084. The Kruskal-Wallis test results at 14 days showed no significant results and at 21 days there were significant differences between groups. The results of the corrosion rate correlation test at 14 and 21 days showed positive results between artificial saliva and chlorhexidine while for artificial saliva with African leaf extract showed negative results. SEM analysis results obtained a difference in the microstructure picture on the surface of stainless steel wire after immersion in artificial saliva, chlorhexidine, and 12.5 mg/ml African leaf extract for 14 and 21 days. In conclusion, there is an effect of the length of immersion of stainless steel orthodontic wires on the corrosion rate and differences in the microstructure of the wire between groups after immersion for 14 and 21 days.