<![CDATA[ABSTRAKPendahuluan: Salah satu bahan pembuatan basis gigi tiruan yang sering digunakan adalah resin akrilik polimerisasi panas, karena memiliki estetis yang baik, tidak toksik serta pembuatan dan pemolesan yang relatif murah, namun ketahanannya terhadap fraktur rendah. Kekuatan resin akrilik polimerisasi panas dapat ditingkatkan dengan penambahan bahan penguat seperti hidroksiapatit yang merupakan biokeramik dan memiliki kemiripan dengan mineral penyusun tulang dan gigi dan telah banyak digunakan di bidang biomedis. Penyerapan air merupakan salah satu sifat resin akrilik polimerisasi panas yang perlu diperhatikan. Penyerapan air dapat memengaruhi sifat-sifat resin akrilik lainnya, seperti perubahan fisis dan menurunkan sifat mekanis sehingga basis menjadi lebih mudah fraktur. Penambahan hidroksiapatit diharapkan dapat meningkatkan sifat mekanis namun tidak meningkatkan penyerapan air resin akrilik. Penelitian eksperimental laboratoris ini bertujuan untuk mengetahui pengaruh penambahan hidroksiapatit 3, 4, dan 6% pada bahan basis gigi tiruan resin akrilik polimerisasi panas terhadap penyerapan air. Metode: Sampel terbuat dari resin akrilik polimerisasi panas berbentuk disk dengan ukuran 50 x 0,5 mm. Sebanyak 28 sampel dibagi menjadi 4 kelompok, yaitu kelompok kontrol dan kelompok penambahan hidroksiapatit 3, 4, dan 6%. Setiap kelompok sampel dihitung nilai penyerapan airnya sesuai prosedur ISO (International Standards Organization). Hasil: Hasil perhitungan penyerapan air dianalisis dengan uji One-way ANOVA dan uji LSD (Least Significance Different) dengan nilai p<0,0001 (p<0,05). nilai penyerapan air semakin tinggi seiring dengan penambahan hidroksiapatit dibandingkan dengan kelompok kontrol. Simpulan: Penambahan hidroksiapatit pada bahan basis gigi tiruan resin akrilik polimerisasi panas dapat memengaruhi nilai penyerapan air. Semakin banyak hidroksiapatit yang ditambahkan, semakin tinggi nilai penyerapan airnya.Kata kunci : Basis gigi tiruan, resin akrilik polimerisasi panas, bahan penguat, hidroksiapatit, penyerapan airThe effect of addition of hydroxyapatite to denture base materials heat cured acrylic resin on water absorption: Laboratory experimentalIntroduction: Heat cured acrylic resin has been used as dental material for making denture bases more aesthetics characterized by non-toxic and relatively cheap to manufacture and polish, but resistance of fracture. Reinforcing agents such as hydroxyapatite can be added to increase the strength of heat cured acrylic resin, its bioceramic and has similarities with minerals of bone and teeth and has been widely used in the biomedical field. Water absorption is one of the characteristics of heat cured acrylic resin that needs to be considered. Water absorption in acrylic resin can affect other characteristics of acrylic resin, such as physical changes and decreased mechanical properties so that the base becomes easier to fracture. Addition of hydroxyapatite is expected to enhance the mechanical properties but not increase water absorption. This experimental laboratory study aims to determine the effect of adding 3, 4, and 6% hydroxyapatite to heat cured acrylic resin denture based on water absorption. Methods: The samples were made of heat cured acrylic resin in disk-shaped measured 50 x 0.5 mm. A total of 28 samples were divided into 4 groups: a control group and group with the addition of hydroxyapatite in various concentrations (3, 4, and 6%). Each group of samples was calculated for water absorption value using the formula from the International Standards Organization. Results: The calculation results of water absorption were analyzed by One-way ANOVA and LSD tests with p value < 0.0001 (p<0.05) the water absorption value was getting higher as the addition of hydroxyapatite compared to the control group. Conclusion: The addition of hydroxyapatite to denture base materials heat cured acrylic resin affects the water absorption value. The more hydroxyapatite added, the higher the water absorption of heat cured acrylic resinKeywords : Denture base, heat cured acrylic resin, reinforcement, hydroxyapatite, water absorption]]>
