Department of Prosthodontics and Periodontics, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
J Mech Behav Biomed Mater. 2024 Aug;156:106569. doi: 10.1016/j.jmbbm.2024.106569. Epub 2024 May 9.
This study aimed to produces and characterize bovine hydroxyapatite (HA) bioceramic with 3Y-TZP addition and analyze different sintering curves. HA was extracted from bovine bones and nanoparticulated. HA discs (0, 1, 5 and 10 wt% 3Y-TZP) were subjected to uniaxial and isostatic pressing. Dilatometry analysis was performed and the groups were sintered using 3 different firing curves (conventional, 1300 °C; 2-step, 1292 °C; 2-step, 1420 °C). The samples were analyzed by X-ray diffraction (XRD), biaxial flexural strength (BFS), Vickers microhardness (VH) and Field emission scanning electron microscopy (FE-SEM). The dilatometry results signaled the need for sintering optimization in groups added with 3Y-TZP. XRD demonstrated the characteristic crystallographic peaks of HA in the pure groups and with 1% 3Y-TZP, and decomposition of HA into β-TCP and formation of calcium zirconate in the groups with 5 and 10% 3Y-TZP. Considering each composition, the groups of pure HA (131.3 ± 13.5 MPa; 401 ± 12.7 GPa) sintered by the conventional curve and HA+1%3Y-TZP (145 ± 8.6 MPa; 507 ± 47.9 GPa), HA+5%3Y-TZP (68.1 ± 14.2 MPa; 183 ± 9.8 GPa) and HA+10%3Y-TZP (55.6 ± 5.1 MPa; 96.1 ± 7.64 GPa) sintered by the 2-step curve at 1420 °C, combined the best BFS and VH results. The addition of 1 wt% 3Y-TZP and optimization in the sintering process improved the mechanical and microstructural properties of HA bioceramics and maintenance of its crystalline characteristics. Refinement in material processing is necessary for the future use of this bioceramic in dentistry.
本研究旨在制备和表征添加 3Y-TZP 的牛羟基磷灰石（HA）生物陶瓷，并分析不同的烧结曲线。从牛骨中提取并纳米化 HA。HA 圆盘（0、1、5 和 10 wt% 3Y-TZP）进行单向和等静压压制。进行热膨胀分析，并用 3 种不同的烧结曲线（常规，1300°C；2 步，1292°C；2 步，1420°C）对各组进行烧结。通过 X 射线衍射（XRD）、双向弯曲强度（BFS）、维氏显微硬度（VH）和场发射扫描电子显微镜（FE-SEM）对样品进行分析。热膨胀分析结果表明需要优化添加 3Y-TZP 的组的烧结。XRD 证明了纯组和添加 1% 3Y-TZP 的组中 HA 的特征结晶峰，以及添加 5%和 10% 3Y-TZP 的组中 HA 分解为β-TCP 和形成钙锆酸盐。考虑到每种成分，纯 HA（131.3±13.5 MPa；401±12.7 GPa）的常规曲线烧结组和纯 HA+1%3Y-TZP（145±8.6 MPa；507±47.9 GPa）、HA+5%3Y-TZP（68.1±14.2 MPa；183±9.8 GPa）和 HA+10%3Y-TZP（55.6±5.1 MPa；96.1±7.64 GPa）的 2 步曲线 1420°C 烧结组，结合了最佳的 BFS 和 VH 结果。添加 1wt% 3Y-TZP 和优化烧结工艺提高了 HA 生物陶瓷的机械和微观结构性能，并保持了其结晶特性。未来在牙科中使用这种生物陶瓷，需要对材料加工进行改进。
