Nueesch Reto, Karlin Sabrina, Fischer Jens, Rohr Nadja
Biomaterials and Technology, Department of Reconstructive Dentistry, University Center for Dental Medicine Basel UZB, University of Basel, 4001 Basel, Switzerland.
Materials (Basel). 2023 Feb 5;16(4):1355. doi: 10.3390/ma16041355.
The aim of this study was to find a suitable material combination to avoid cement excess in the marginal region of one-piece zirconia implant-supported restorations by means of a hybrid crown consisting of a meso- and a suprastructure. One-piece zirconia implants ( = 120) were embedded in epoxy resin. Microfilled resin composite mesostructures ( = 60), designed as caps, were bonded on the implant abutment with a primer only. A molar crown was constructed and cemented with a resin cement on top of the mesostructure as a suprastructure out of feldspar ceramic ( = 12), lithium-disilicate ( = 24), or zirconia ( = 24). Fracture load ( = 6) and retention force ( = 6) were measured immediately after storage in distilled water at 37 °C for 24 h, as well as after an additional exposure to artificial aging in a chewing simulator and simultaneous thermal cycling. For the measurement of the fracture load, monolithic crowns made of the employed restorative materials and identical in shape to the hybrid crowns served as controls ( = 6 each). Fracture load values for feldspar ceramic and lithium-disilicate hybrid crowns were slightly higher than those for the respective monolithic crowns at baseline and after aging, which was statistically significant only for feldspar crowns after aging. In contrast, fracture load values for zirconia monolithic crowns were higher than those for zirconia hybrid crowns, which was only statistically significant after aging. Artificial aging reduced the fracture load of feldspar and lithium-disilicate crowns both for hybrid and monolithic crowns. The effect was only statistically significant for lithium disilicate hybrid crowns. The fracture load for hybrid and monolithic zirconia crowns was increased by artificial aging without reaching statistical significance. The retention force of lithium-disilicate and zirconia hybrid crowns was not affected by artificial aging. Taking into account retention force and fracture load, lithium-disilicate hybrid crowns showed promising results.
本研究的目的是通过由中层结构和上层结构组成的混合冠，找到一种合适的材料组合，以避免一体式氧化锆种植体支持修复体边缘区域出现水泥过量的情况。将一体式氧化锆种植体（n = 120）嵌入环氧树脂中。设计为帽状的微填料树脂复合材料中层结构（n = 60）仅用底漆粘结在种植体基台上。制作了一个磨牙冠，并使用树脂粘结剂将其作为由长石陶瓷（n = 12）、二硅酸锂（n = 24）或氧化锆（n = 24）制成的上层结构粘结在中层结构顶部。在37℃蒸馏水中储存24小时后，以及在咀嚼模拟器中进行额外的人工老化和同时进行热循环后，立即测量断裂载荷（n = 6）和固位力（n = 6）。为了测量断裂载荷，由所用修复材料制成且形状与混合冠相同的整体冠用作对照（每组n = 6）。长石陶瓷和二硅酸锂混合冠的断裂载荷值在基线和老化后略高于相应的整体冠，仅长石冠在老化后具有统计学意义。相比之下，氧化锆整体冠的断裂载荷值高于氧化锆混合冠，仅在老化后具有统计学意义。人工老化降低了长石和二硅酸锂混合冠及整体冠的断裂载荷。该效应仅在二硅酸锂混合冠中具有统计学意义。人工老化增加了混合冠和整体氧化锆冠的断裂载荷，但未达到统计学意义。二硅酸锂和氧化锆混合冠的固位力不受人工老化影响。考虑到固位力和断裂载荷，二硅酸锂混合冠显示出有前景的结果。
