PERBANDINGAN KEKUATAN FLEXURAL ANTARA ORIENTASI UNIDIRECTIONAL DAN BIDIRECTIONAL FIBER Agave sisalana PADA FIBER REINFORCED COMPOSITE

ERFANDI AHMAD, drg. Purwanto Agustiono, S.U., drg. Dyah Irnawati, M.S.

2014 | Skripsi | PENDIDIKAN DOKTER GIGI

Fiber reinforced composite (FRC) merupakan material yang mengandung bahan utama yaitu matriks dan diperkuat oleh fiber. Aplikasi FRC di dalam rongga mulut sebagai splinting membutuhkan sifat kekuatan flexural yang cukup untuk menahan gaya mastikasi. Salah satu faktor yang dapat mempengaruhi kekuatan flexural FRC adalah orientasi fiber. Penelitian ini bertujuan untuk mengetahui perbandingan kekuatan flexural antara susunan unidirectional dan bidirectional fiber sisal (Agave sisalana) pada FRC. Bahan penelitian ini adalah FRC dengan matriks flowable composite (Master Flow, Brazil) dan fiber sisal (Agave sisalana) (Balittas, Indonesia). Sampel FRC berbentuk balok dengan ukuran 25x2x2mm (ISO 9917-2). Sampel FRC pada penelitian dibuat dengan orientasi fiber unidirectional (kelompok 1) dan orientasi bidirectional (kelompok 2) yang masing-masing kelompok berjumlah 4 buah sampel. Sampel diukur dengan alat universal testing machine dengan kecepatan tekan 1 mm/menit. Data kekuatan flexural kemudian dianalisis secara statistik menggunakan independent t-test (α = 0,05). Hasil penelitian menunjukkan rerata kekuatan flexural FRC dengan fiber sisal (Agave sisalana) orientasi unidirectional 36,56 ± 2,91 MPa dan orientasi bidirectional 24,09 ± 2,08 MPa. Hasil independent t-test menunjukkan terdapat perbedaan kekuatan flexural yang bermakna antara orientasi unidirectional dan orientasi bidirectional (p<0,05). Kesimpulan penelitian ini adalah kekuatan flexural FRC fiber sisal (Agave sisalana) dengan orientasi unidirectional lebih besar dibandingkan dengan orientasi bidirectional. Kata kunci: FRC, fiber sisal, orientasi fiber, kekuatan flexural.

Fiber reinforced composite (FRC) is a material that contains a matrix as the main component and is reinforced with fibers. FRC application in an oral cavity as a splinting requires a considerable flexural strength to withstand the mastication force. One of the factors that can influence the flexural strength is fiber orientation. The aim of study was to compare the flexural strength between unidirectional orientation and bidirectional orientation of sisal fiber (Agave sisalana) on FRC. This research material was FRC with a flowable composite matrix (Master Flow, Brazil) and sisal fiber (Agave sisalana) (Balittas, Indonesia). Sample of FRC was a bar with the size 25x2x2mm (ISO 9917-2). Sample of FRC was made with unidirectional fiber orientation (group 1) and bidirectional orientation (group 2), each group consists of 4 pieces samples.The flexural strength was measured using the universal testing machine with a speed of 1mm/min. Flexural strength data were analyzed statistically using an independent t-test (α= 0,05). The results showed that the average flexural strength of FRC with fiber sisal (Agave sisalana) unidirectional orientation was 36.56 ± 2.91 MPa and the one with bidirectional orientation was 24.09 ± 2.08 MPa. The independent t-test showed a significant difference in flexural strength between unidirectional orientation and bidirectional orientation fiber (p <0.05). This study reveals that the flexural strength of FRC fiber (Agave sisalana) with a unidirectional orientation was greater than the bidirectional one. Key word: FRC, sisal fiber, fiber orientation, flexural strength.

Kata Kunci : FRC, sisal fiber, fiber orientation, flexural strength.