Application of 10% Ascorbic Acid Improves Resin Shear Bond Stregth in Bleached Dentin

Abstract

Restoration of the teeth immediately after bleaching with H 2 O 2 35% is contraindicated due to the remnants of free radical that will stay inside dentin for 2-3 weeks which will compromise the adhesiveness of composite resin. Objective: The aim of this study was to evaluate the influence of 10% ascorbic acid on shear bond strength of composite placed on bleached dentin. Methods: Twenty seven samples were divided equally into three groups. Group 1: dentin was etched with 35% phosphoric acid; Group 2: dentin was bleached with 35% H 2 O 2 followed by etching with 35% phosphoric acid; Group 3: dentin was bleached with 35% H 2 O 2 , followed by application of 10% ascorbic acid and etched with 35% phosphoric acid. All samples were then stored at 37 0 C for 24 hours. The Universal Testing Machine was used to measure shear bond strength and the results were analyzed with Kruskal Wallis and Mann Whitney test. Results: After nine independent experiments, 10% ascorbic acid application on bleached dentin resulted in highest increased in bond stregth (56.04±11.06MPa) compared to Group 2 (29.09±7.63MPa) and Group 1 (25.55±2.22MPa) and the difference was statistically significant (p<0.05). Conclusion: Application of 10% ascorbic acid to the bleached dentin improved the shear bond strength of resin composite. ABSTRAKAplikasi asam askorbat 10% meningkatkan shear bond strength resin pada dentin pasca pemutihan gigi. Gigi pasca pemutihan gigi interna merupakan kontra indikasi untuk segera dilakukan restorasi, karena adanya radikal bebas yang masih tertinggal di dalam dentin selama 2-3 minggu dan dapat menggangu adaptasi bahan restorasi resin komposit. Tujuan: Menganalisis pengaruh aplikasi asam askorbat 10% terhadap shear bond strength resin komposit pada dentin pasca pemutihan gigi interna dengan gel H 2 O 2 35%. Metode: Dua puluh tujuh sampel gigi dibagi menjadi tiga kelompok. Grup 1: Dentin dietsa dengan asam fosfat 35%; Grup 2: Dentin dilakukan pemutihan gigi interna dengan gel H 2 O 2 35%, dietsa dengan asam fosfat 35%; Grup 3: Dentin dilakukan pemutihan gigi interna dengan gel H 2 O 2 35%, aplikasi asam askorbat 10% selama 10 menit, dan dietsa dengan asam fosfat 35%. Semua gigi percobaan di inkubasi pada 37°C selama 24 jam. Uji shear bond strength dilakukan dengan alat Universal Testing Machine. Data yang diperoleh dianalisis secara statistik dengan tes Kruskal Wallis dan Mann Whitney. Hasil: Analisis sembilan sampel dari masing-masing grup menunjukkan bahwa peningkatan shear bond strength yang paling banyak terjadi pada Grup 3 (56,04±11,06MPa) dibanding dengan Grup 2 (29,09±7,63MPa) dan Grup 1 (25,55±2,22MPa) dan perbedaannya bermakna secara statistik (p<0,05). Simpulan: Aplikasi asam askorbat 10% pada dentin pasca pemutihan gigi interna dengan gel H 2 O 2 35% dapat meningkatkan shear bond strength resin komposit.