Kekuatan Tarik Kawat Ortodonti Berbahan Nikel Titanium Setelah Perendaman Ekstrak Daun Jambu Biji (Psidium Guajava Linn) Selama 10, 20, Dan 30 Hari

Abstract

Nickel–titanium (NiTi) is one type of wire material used in orthodontic treatment. Corrosion causes the release of nickel ions, which can affect the tensile strength of NiTi. Tannin compounds in guava leaf extract are capable of reducing the corrosion rate. The aim of this study was to determine the differences in the tensile strength of nickel–titanium orthodontic wires after immersion in 100 ppm guava leaf extract (Psidium guajava Linn) for 10, 20, and 30 days. This study was a laboratory experimental study with a Post Test Only Group Design. A total of 27 pieces of nickel–titanium wire measuring 6 cm were divided into three groups: immersion in 100 ppm guava leaf extract for 10 days (group 1), 20 days (group 2), and 30 days (group 3), with nine samples in each group (n = 9). The guava leaf extract was prepared using the maceration method. The NiTi wire samples were immersed in 100 ppm guava leaf extract and stored in an incubator at 37°C. Tensile strength was measured using a Universal Testing Machine (UTM). The tensile strength of nickel–titanium wires after immersion in 100 ppm guava leaf extract was 510.36 MPa for group 1 (10 days), 456.95 MPa for group 2 (20 days), and 425.68 MPa for group 3 (30 days). The results showed that the data were normally distributed and homogeneous. One-way ANOVA analysis indicated a significant difference in the tensile strength of nickel–titanium wires after immersion in 100 ppm guava leaf extract for 10, 20, and 30 days (p < 0.05). In conclusion, the longer the wire is exposed to 100 ppm guava leaf extract, the greater the decrease in its tensile strength.