ABSTRACTBackground: Heat cured type acrylic resin denture base has water absorption properties that can affect the surface roughness of acrylic resin. An alternative denture cleanser is needed to minimize the effects arising from chemicals. A 100% small ginger extract can be used as an alternative to natural denture cleanser. Objective: The purpose of this study was to analyze the effect of 100% small white ginger extract immersion on the surface roughness value of heat cured acrylic resin. Methods: This research was a true experimental method with a post-test only and control group design. One Way ANOVA test was performed to analyze the data which was followed by Bonferroni Post Hoc test. The sample is in the form of rectangular plate with a size of 65x10x3.3 mm. The number of research samples were 21 pieces were divided into 3 immersion groups, namely the group solution of 100% small white ginger extract, alkaline peroxide, and distilled water. Measurement of sample surface roughness was obtained by using Surface Roughness Tester. Results: The mean value of surface roughness in the group of 100% small white ginger extract was 0.112, the alkaline peroxide group was 0.131, and the aquades group was 0.104. The results of the One Way ANOVA parametric test obtained p = 0,000 (p <0.05) and continued with Bonferroni's Post Hoc test. Conclusion: There is a smaller effect after immersion in 100% small white ginger extract on the surface roughness of heat cured acrylic resin compared to the soaking in alkaline peroxide. Keywords: 100% small ginger extract, surface roughness, heat cured acrylic resin ABSTRAKLatar Belakang: Basis gigi tiruan resin akrilik tipe heat cured mempunyai sifat penyerapan air yang dapat mempengaruhi kekasaran permukaan resin akrilik. Diperlukan alternatif denture cleanser untuk meminimalkan efek yang timbul dari bahan kimia. Ekstrak jahe putih kecil 100% dapat digunakan sebagai alternatif denture cleanser berbahan alami. Tujuan: Tujuan penelitian ini adalah untuk menganalisis pengaruh perendaman ekstrak jahe putih kecil 100% terhadap nilai kekasaran permukaan resin akrilik tipe heat cured. Metode: Penelitian ini menggunakan metode true experimental (eksperimental laboratoris murni) dengan rancangan post-test only with control group design dan uji One Way ANOVA yang dilanjutkan dengan uji Post Hoc Bonferroni. Sampel berbentuk persegi panjang dengan ukuran 65x10x3,3 mm. Jumlah sampel penelitian sebanyak 21 buah yang dibagi menjadi 3 kelompok perendaman, yaitu kelompok larutan ekstrak jahe putih kecil 100%, alkalin peroksida, dan akuades. Pengukuran nilai kekasaran permukaan sampel menggunakan alat Surface Roughness Tester. Hasil: Nilai rerata kekasaran permukaan kelompok ekstrak jahe putih kecil 100% sebesar 0,112, kelompok alkalin peroksida sebesar 0,131, dan kelompok akuades sebesar 0,104. Hasil uji parametrik One Way ANOVA didapatkan nilai p=0,000 (p<0,05) dan dilanjutkan uji Post Hoc Bonferroni. Kesimpulan: Terdapat pengaruh lebih kecil setelah dilakukan perendaman dalam ekstrak jahe putih kecil 100% terhadap kekasaran permukaan resin akrilik tipe heat cured dibandingkan dengan perendaman dalam alkalin peroksida. Kata kunci: Ekstrak jahe putih kecil 100%, kekasaran permukaan, resin akrilik tipe heat cured