Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON M5G 1G6, Canada; Institute of Biomaterials and Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Rosebrugh Building, Room 407, 164 College Street, Toronto, ON M5S 3G9, Canada; Department of Prosthodontics, Faculty of Dentistry, Jordan University of Science & Technology (JUST), P.O. Box 3030, Irbid 22110, Jordan.
Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON M5G 1G6, Canada.
Dent Mater. 2019 Nov;35(11):1545-1556. doi: 10.1016/j.dental.2019.07.009. Epub 2019 Aug 7.
To evaluate ultrashort-pulse laser (UPL) as a surface treatment for improved bond strength to Yttria-tetragonal zirconia polycrystalline (Y-TZP).
Fully-sintered Y-TZP samples received either no treatment (CTL), or were treated by alumina blasting (ALB), tribochemical silica coating (SIL), or one of two UPL patterns: multiple pulses laser surface dots with 2.5μm spacing (8mJ, 10kHz)(LSD); or single pulse laser surface lines with 2.5μm spacing (4mJ, 6.7kHz)(LSL). Surface roughness, wettability (contact angle), and quantification of crystalline phases were evaluated for each group (n=3/group). Y-TZP treated slabs were cemented to resin composite slabs using silane and 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing adhesive. Beams from the Y-TZP/resin blocks were microtensile tested (n=5/group) after 48h water incubation (37°C) with or without subsequent thermocycling (5-55°C, 5000 cycles).
All surface treatments increased surface roughness values versus control (P<0.001). Contact angles were lowest for SIL (6.57±2.37°) and highest for control (50.97±6.30°). LSL and LSD were the only treatments that did not increase the relative monoclinic phase. All surface treatments significantly increased microtensile bond strengths (μTBS) compared with the control group (P<0.001), with highest values for UPL (LSD: 35.40±4.53MPa>LSL: 31.84±8.46MPa>SIL: 19.95±3.99MPa=ALB: 19.51±2.55MPa>CTL: 14.51±2.23MPa). Thermocycling significantly reduced bond strength for all treatments in a surface treatment-dependent manner.
The ability of UPL to alter Y-TZP surface morphology, increase wettability and μTBS without increasing the monoclinic content suggests its potential to improve bonding to the underlying resin cement and tooth without compromising the strength of the restoration.
评估超短脉冲激光（UPL）作为改善氧化钇四方相氧化锆多晶（Y-TZP）粘结强度的表面处理方法。
全烧结 Y-TZP 样本分别接受无处理（CTL）、氧化铝喷砂（ALB）、硅烷化和含 10-甲氧基癸基二氢磷酸酯（MDP）的胶接剂处理、或两种 UPL 模式之一处理：多点激光表面打点，间距 2.5μm（8mJ，10kHz）（LSD）；或单脉冲激光表面划线，间距 2.5μm（4mJ，6.7kHz）（LSL）。每组（n=3）评估表面粗糙度、润湿性（接触角）和晶体相定量。用硅烷和含 10-甲氧基癸基二氢磷酸酯（MDP）的胶接剂将 Y-TZP 处理的薄片粘结到树脂复合材料薄片上。将 Y-TZP/树脂块的梁在 37°C 下 48h 水孵育（37°C）后进行微拉伸测试（n=5），然后进行热循环（5-55°C，5000 次循环）。
与对照组相比，所有表面处理均增加了表面粗糙度值（P<0.001）。接触角最低的是 SIL（6.57±2.37°），最高的是对照组（50.97±6.30°）。LSL 和 LSD 是唯一不增加单斜相的处理方法。与对照组相比，所有表面处理均显著提高了微拉伸粘结强度（μTBS）（P<0.001），其中 UPL 最高（LSD：35.40±4.53MPa>LSL：31.84±8.46MPa>SIL：19.95±3.99MPa=ALB：19.51±2.55MPa>CTL：14.51±2.23MPa）。热循环以表面处理依赖性方式显著降低了所有处理的粘结强度。
UPL 改变 Y-TZP 表面形态、增加润湿性和 μTBS 的能力而不增加单斜含量表明，它有可能在不损害修复体强度的情况下改善与底层树脂胶和牙齿的粘结。
