ABSTRAK Pendahuluan: Gigi tiruan menjadi solusi untuk menggantikan gigi yang hilang. Gigi tiruan cekat dengan bahan porcelain fused to metal paling sering digunakan dalam praktik klinis  namun memiliki kekurangan seperti memicu efek alergenik, memerlukan beberapa kali kunjungan, dan membutuhkan preparasi gigi abutment yang cukup luas. Alternatif bahan yang dapat digunakan untuk gigi tiruan cekat adalah Fiber reinforced composite dengan E-glass fiber dental yang memiliki kelebihan seperti biokompatibilitas baik, memiliki kekuatan kompresi dan estetika yang baik. Ketersediaan E-glass fiber dental di Indonesia masih terbatas dengan harga yang cukup mahal. E-glass fiber non dental secara umum telah digunakan di bidang teknik yang memiliki komposisi hampir sama dengan E-glass fiber dental. Tujuan dari penelitian ini untuk menganalisis perbedaan volumetrik E-glass fiber non dental terhadap kekuatan fleksural Fiber reinforced composite. Metode: Penelitian Fiber reinforced composite berbentuk balok ukuran 25mm x 2mm x 2 mm yang terbagi menjadi 4 kelompok  yaitu kelompok kontrol E-glass fiber dental volumetrik 3,8 vol % dan kelompok dengan E-glass fiber non dentalvolumetrik 0 vol %, volumetrik 3,8 vol %, volumetrik 7,3 vol % dengan jumlah 6 sampel masing-masing kelompok lalu diuji dengan alat Universal Testing Machine (UTM). Analisis data menggunakan uji One Way Anova. Hasil: hasil uji pada Fiber reinforced composite pada kelompok volumetrik7,3 vol % memiliki kekuatan fleksural tertinggi dengan nilai 220,51 MPa dan pada volumetrik 0 vol % memiliki nilai terendah 158,27 MPa. Hasil uji one way ANOVA dengan nilai p = 0,000 (<0,05) Simpulan: Terdapat perbedaan volumetrik E-glass fiber non dental terhadap kekuatan fleksural Fiber reinforced composite. Kata kunci E-glass fiber non dental, Fiber reinforced composite, Kekuatan fleksural, Volumetrik fiber Differences of volumetric e-glass fiber non-dental on flexural strength of fiber reinforced composite : study experimental ABSTRACT Introduction: Dentures are a solution to replace missing teeth. Porcelain-fused-to-metal fixed dentures are most commonly used in clinical practice but have disadvantages such as triggering allergic reactions, requiring multiple visits, and requiring extensive abutment tooth preparation. An alternative material that can be used for a fixed denture is fiber-reinforced composite (FRC)with E-glass fiber, which offers advantages such as good biocompatibility, compressivestrength and favorableaesthetics. However, the availability of dental-grade E-glass fiber in Indonesia is still relativelyexpensive. Non-dental E-glass fiber, commonlyused in the engineering field which has almost the same composition as dental E-glass fiber. The purpose of this study was to analyze the different volumes of non-dental E-glass fiber on the flexural strength of fiber-reinforced composite. Methods: This was anexperimental study using fiber-reinforced composite blocks containing non-dental E-glass fiber. Each block measured 25 mm x 2 mm x 2 mm and was divided into four groups, a control group with dentalE-glass fiber at 3,8 vol% and three groups with non-dentalE-glass fiber at 0 vol%, 3.8 vol%, and 7.3 vol%, respectively. Each group included six samples,which were tested using a Universal Testing Machine (UTM). Data were analyzed usingOne-Way Anova. Results: The group with non-dental E-glass fiber at 7.3 vol% demonstrated the highest flexural strength, with a value of 220.51 MPa. The group with 3.8 vol% fiber showed a flexural strength of 201.61 MPa, while the group without fiber (0 vol%) had the lowest strength at158.27 MPa. Conclusion: There is a significant difference in the flexural strength of fiber-reinforced composite depending on the volume of non-dental E-glass fiber used. Keywords E-glass fiber non dental, Fiber reinforced composite, Flexural strength, Volumetric fiber