Pendahuluan: Basis gigi tiruan nilon termoplastik merupakan alternatif pengganti basis gigi tiruan resin akrilik. Pembersihan gigi tiruan diperlukan untuk menjaga basis gigi tiruan agar tetap bersih dari kontaminasi mikroorganisme. Daun seledri merupakan bahan alam yang memiliki kandungan flavonoid, saponin, tanin, dan minyak atsiri yang sudah terbukti bersifat antijamur. Penelitian sebelumnya hanya melihat zona hambat saja. Tujuan penelitian adalah menganalisis efektivitas perasan daun seledri sebagai pembersih gigi tiruan terhadap pertumbuhan Candida albicans pada basis gigi tiruan nilon termoplastik. Metode: Eksperimental laboratoris dengan rancangan penelitian post-test only control group design. Sampel nilon termoplastik berbentuk cakram dengan diameter 10 mm dan tebal 2 mm sebanyak 25 dibagi menjadi 5 kelompok. Sampel dikontaminasi dengan C. albicans setelah direndam dalam kontrol negatif (akuades) selama 6 jam, kontrol positif (tablet effervescent) selama 15 menit, dan perasan daun seledri konsentrasi 25, 50, dan 100% selama 6 jam. Sampel selanjutnya diletakkan dalam media sabouraud dextrose broth (SDB). Pengujian efektivitas perasan daun seledri dilakukan dengan menentukan nilai absorbansi kekeruhan media SDB menggunakan spektrofotometer. Data dianalisis menggunakan one-way ANOVA dan Least Significant Difference (LSD). Hasil: Nilai konsentrasi C. albicans pada kelompok kontrol negatif mendapatkan hasil 0,380 x 108 CFU/mL, kontrol positif mendapatkan hasil 0,310 x 108 CFU/mL, perasan daun seledri konsentrasi 25% mendapatkan hasil 0,243 x 108 CFU/mL, konsentrasi 50% mendapatkan hasil 0,160 x 108 CFU/mL, dan konsentrasi 100% mendapatkan hasil 0,236 x 108 CFU/mL. Simpulan: Perasan daun seledri efektif sebagai pembersih gigi tiruan untuk menghambat pertumbuhan C. albicans, dengan konsentrasi yang efektif sebesar 50%.Kata kunci: Nilon termoplastik, perasan daun seledri, Candida albicans. ABSTRACTIntroduction: Thermoplastic nylon denture base is an alternative to the acrylic resin denture base. Denture cleaning is needed to keep the denture base clean from contamination by microorganisms. Celery leaves are natural ingredients that contain flavonoids, saponins, tannins, and essential oils that have been proven to have antifungal properties. Previous research only observed the inhibitory zone. This research was aimed to analyse the effectiveness of celery leaf juice as a denture cleaner against the growth of Candida albicans on thermoplastic nylon denture base. Methods: Experimental laboratory with a post-test only control group design was conducted towards 25 disc-shaped thermoplastic nylon samples with a diameter of 10 mm and a thickness of 2 mm, and divided into five groups. Samples were contaminated with C. albicans after immersion in the negative control (aquadest) for 6 hours, positive control (effervescent tablets) for 15 minutes, and celery leaf juice with the concentrations of 25, 50, and 100% for 6 hours. The sample was then placed in the Sabouraud-dextrose broth (SDB) medium. The effectiveness of celery leaf juice was tested by determining the absorbance value of SDB media turbidity using a spectrophotometer. Data were analysed using one-way ANOVA and Least Significant Difference (LSD). Results: The concentration value of C. albicans in the negative control group was 0.380 x 108 CFU / mL, the positive control was 0.310 x 108 CFU / mL, the juice of celery leaves with the concentration of 25% was 0.243 x 108 CFU / mL, the concentration of 50% was 0.160 x 108 CFU / mL, and the concentration of 100% was 0.236 x 108 CFU / mL. Conclusion: Celery leaf juice is effective as a denture cleaner to inhibit the growth of C. albicans, with an effective concentration of 50%.Keywords: Thermoplastic nylon, celery leaf juice, Candida albicans.