title: Effects of Acid Treatment on Dental Zirconia: An In Vitro Study.
abstract: The aim of this study was to evaluate the effects of hydrofluoric (HF) acid, acetic acid, and citric acid treatments on the physical properties and structure of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) at ambient temperature. In total, 110 bar-shaped zirconia specimens were randomly assigned to 11 groups. The specimens in the control group (C) received no surface treatment, while those in the Cage group were hydrothermally aged at 134°C and 0.2 MPa for 20 h. Ten specimens each were immersed at ambient temperature in 5% and 40% HF acid for 2 h (40HF0), 1 day (5HF1, 40HF1), and 5 days (5HF5, 40HF5), while 10 each were immersed at ambient temperature in 10% acetic acid and 20% citric acid for 7 (AC7, CI7) and 14 days (AC14, CI14). X-ray diffraction (XRD) was used to quantitatively estimate the monoclinic phase. Furthermore, flexural strength, surface roughness, and surface Vickers hardness were measured after treatment. Scanning electron microscopy (SEM) was used to characterize the surface morphology. The Cage group specimens exhibited an increased monoclinic phase and flexural strength. Furthermore, 40% HF acid immersion decreased the flexural strength and surface hardness and deteriorated the surface finish, while 5% HF acid immersion only decreased the surface hardness. All the HF acid-immersed specimens showed an etched surface texture on SEM observations, while the other groups did not. These findings suggest that the treatment of Y-TZP with 40% HF acid at ambient temperature causes potential damage, while treatment with 5% HF acid, acetic acid, and citric acid is safe.
authors: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
authors: Haifeng
authors: H
authors: Xie
authors: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
authors: Shuping
authors: S
authors: Shen
authors: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
authors: Mengke
authors: M
authors: Qian
authors: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
authors: Feimin
authors: F
authors: Zhang
authors: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Department of Endodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
authors: Chen
authors: C
authors: Chen
authors: Department of Endodontics, College of Dental Medicine, Georgia Regents University, Augusta, Georgia, United States of America.
authors: Franklin R
authors: FR
authors: Tay
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology; D019343:Citric Acid / Q000494:pharmacology; D003764:Dental Materials; D017266:Dental Prosthesis; D006801:Humans; D006858:Hydrofluoric Acid / Q000494:pharmacology; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D014961:X-Ray Diffraction; D015019:Yttrium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003764:Dental Materials; C499362:yttria stabilized tetragonal zirconia; D019343:Citric Acid; D015019:Yttrium; D015040:Zirconium; D019342:Acetic Acid; D006858:Hydrofluoric Acid