Han Aifang, Ding Hao, Tsoi James Kit Hon, Imazato Satoshi, Matinlinna Jukka P, Chen Zhuofan
Dental Materials Science, Division of Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong SAR, P.R. China.
Department of Biomaterials Science, Osaka University Graduate School of Dentistry, Osaka 565-0871, Japan.
ACS Omega. 2020 Mar 5;5(10):5126-5133. doi: 10.1021/acsomega.9b04123. eCollection 2020 Mar 17.
Zirconia has become an excellent choice of dental implants because of its excellent mechanical strength, aesthetic, and biocompatibility. Although some studies have shown ultraviolet (UV) irradiation is effective to photofunctionalize dental zirconia that can improve osteoblastic function, the scattered information has not identified the most effective exposure time and wavelength of UV. Herein, this study has investigated the effects of UV irradiation on zirconia after UV-A (365 nm) or UV-C (243 nm) photofunctionalization for different times (15 min, 3 and 24 h). After irradiation, the zirconia surface was analyzed by color spectrophotometry, scanned electron microscopy (SEM), energy-dispersive X-ray spectrometry, water contact angle (WCA) with goniometer, and X-ray diffraction. Osteoblastic (MC3T3-E1) cells were cultured on zirconia discs and evaluated with a CCK-8 test kit for cell proliferation (3 h and 1 day) and with alkaline phosphatase (ALP) activity (14 days). Significant color change (Δ) was observed by irradiating with UV-C for 15 min (1.99), 3 h (1.92), and 24 h (3.35), whereas only minute changes were observed with UV-A (respectively, Δ: 0.18, 0.14, 0.57). No surface textural changes were observed nor a monoclinic phase was detected on both the UV-A and UV-C irradiated samples. UV-C significantly decreased the C/Zr ratios and WCA, with irradiating for 24 h presenting the lowest values, and it was the only condition to give significantly higher ALP activity at 14 days ( < 0.05) and CCK-8 values for 1 day culture ( < 0.05). It is concluded that UV-C (but not UV-A) irradiation can significantly change the aesthetic in color, and only prolonged 24 h UV-C irradiation can enhance MC3T3-E1 cell adhesion on zirconia by photofunctionalization.
由于具有出色的机械强度、美观性和生物相容性，氧化锆已成为牙科植入物的理想选择。尽管一些研究表明紫外线（UV）照射可有效使牙科氧化锆实现光功能化，从而改善成骨细胞功能，但零散的信息尚未确定紫外线最有效的照射时间和波长。在此，本研究调查了在不同时间（15分钟、3小时和24小时）进行UV-A（365纳米）或UV-C（243纳米）光功能化后，紫外线照射对氧化锆的影响。照射后，通过比色分光光度法、扫描电子显微镜（SEM）、能量色散X射线光谱法、用测角仪测量水接触角（WCA）以及X射线衍射对氧化锆表面进行分析。将成骨细胞（MC3T3-E1）培养在氧化锆圆盘上，并用CCK-8检测试剂盒评估细胞增殖情况（3小时和1天）以及碱性磷酸酶（ALP）活性（14天）。用UV-C照射15分钟（Δ为1.99）、3小时（Δ为1.92）和24小时（Δ为3.35）时观察到显著的颜色变化，而用UV-A照射时仅观察到微小变化（分别为Δ：0.18、0.14、0.57）。在UV-A和UV-C照射的样品上均未观察到表面纹理变化，也未检测到单斜相。UV-C显著降低了C/Zr比率和WCA，照射24小时时呈现出最低值，并且这是唯一在14天时能使ALP活性显著更高（<0.05）以及在培养1天时使CCK-8值显著更高（<0.05）的条件。得出的结论是，UV-C（而非UV-A）照射可显著改变颜色美观度，并且只有延长24小时的UV-C照射才能通过光功能化增强MC3T3-E1细胞在氧化锆上的黏附。
