[ABSTRAK
Penelitian ini bertujuan untuk membandingkan perubahan warna bahan polyamide 12 dan polyamide mikrokristalin. Masing-masing bahan dibagi menjadi 2 kelompok yaitu yang dipoles dengan alat dan bahan yang terdapat di laboratorium dan di klinik. Kemudian keempat kelompok dilakukan perendaman dalam larutan kopi selama 24 jam dalam 7 hari. Pengukuran kekasaran dinilai dengan alat profilometer sebelum perendaman dan pengukuran warna dengan spektrofotometer dilakukan sebelum dan setelah perendaman dengan menggunakan 3 nilai, L*, a*, dan b*.Hasil penelitian menunjukkan tidak terdapat perbedaan perubahan warna yang bermakna pada basis gigi tiruan Polyamide 12 dibandingkan dengan Polyamide mikrokristalin yang direndam dalam larutan kopi setelah pemolesan.

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ABSTRACT
The purpose of this study was to compare color changes from polyamide 12 andpolyamide microcrystalline.Each material was divided into two groups whichpolished with laboratory and clinic polishing equipmentand then immersed in28␣C coffee solution for 24 hours in 7 days. Surfaceroughness were measuredwith profilometerbefore the immersion. Color (L *, a *, and b *) weremeasuredusing spectrophotometer before and after immersion. There were nosignificant color changes in Polyamide 12 and polyamide microcrystalline afterimmersion in coffee solution.;The purpose of this study was to compare color changes from polyamide 12 andpolyamide microcrystalline.Each material was divided into two groups whichpolished with laboratory and clinic polishing equipmentand then immersed in28␣C coffee solution for 24 hours in 7 days. Surfaceroughness were measuredwith profilometerbefore the immersion. Color (L *, a *, and b *) weremeasuredusing spectrophotometer before and after immersion. There were nosignificant color changes in Polyamide 12 and polyamide microcrystalline afterimmersion in coffee solution.;The purpose of this study was to compare color changes from polyamide 12 andpolyamide microcrystalline.Each material was divided into two groups whichpolished with laboratory and clinic polishing equipmentand then immersed in28␣C coffee solution for 24 hours in 7 days. Surfaceroughness were measuredwith profilometerbefore the immersion. Color (L *, a *, and b *) weremeasuredusing spectrophotometer before and after immersion. There were nosignificant color changes in Polyamide 12 and polyamide microcrystalline afterimmersion in coffee solution.;The purpose of this study was to compare color changes from polyamide 12 andpolyamide microcrystalline.Each material was divided into two groups whichpolished with laboratory and clinic polishing equipmentand then immersed in28␣C coffee solution for 24 hours in 7 days. Surfaceroughness were measuredwith profilometerbefore the immersion. Color (L *, a *, and b *) weremeasuredusing spectrophotometer before and after immersion. There were nosignificant color changes in Polyamide 12 and polyamide microcrystalline afterimmersion in coffee solution., The purpose of this study was to compare color changes from polyamide 12 andpolyamide microcrystalline.Each material was divided into two groups whichpolished with laboratory and clinic polishing equipmentand then immersed in28␣C coffee solution for 24 hours in 7 days. Surfaceroughness were measuredwith profilometerbefore the immersion. Color (L *, a *, and b *) weremeasuredusing spectrophotometer before and after immersion. There were nosignificant color changes in Polyamide 12 and polyamide microcrystalline afterimmersion in coffee solution.]