Dinu Mihaela, Cotrut Cosmin Mihai, Vladescu Dragomir Alina, Baciu Florin, Parau Anca Constantina, Pana Iulian, Constantin Lidia Ruxandra, Vitelaru Catalin
Department for Advanced Surface Processing and Analysis by Vacuum Technologies, National Institute of Research and Development for Optoelectronics-INOE 2000, 077125 Magurele, Romania.
Faculty of Materials Science and Engineering, National University of Science and Technology Politehnica Bucharest, 060042 Bucharest, Romania.
Dent J (Basel). 2025 Jul 14;13(7):318. doi: 10.3390/dj13070318.
The increasing demand for aesthetics in dentistry has driven significant advancements in both materials and techniques. The primary cause of ceramic detachment in dental restorations is extensive mechanical stress, which often results in detachment and clinical complications. This study aims to improve the bond strength between NiCr-based metal frameworks and ceramic coatings by introducing biocompatible inorganic SiON thin films ( = Cr or Zr) as interlayers. SiON coatings with a thickness of ~2 μm were deposited on NiCr alloy using cathodic arc evaporation. To tailor the stoichiometry, morphology, and mechanical properties of the coatings, the substrate bias voltage was varied: -50 V, -100 V, -150 V, -200 V. Structural and surface characterization was performed using SEM/EDS, XRD, profilometry, and contact angle analysis. The coating adhesion was evaluated by using standardized scratch testing, while the bond strength was evaluated using a three-point bending test. The NiCr alloy exhibited a dendritic microstructure, and the ceramic layer consisted mainly of quartz, feldspar, kaolin, and ZrO. ZrSiON coatings showed superior roughness, elemental incorporation, and adhesion compared to Cr-based coatings, these properties being further improved by increasing the substrate bias. The highest bond strength was achieved with a ZrSiON coating deposited at -200 V, a result we attributed to increased surface roughness and mechanical interlocking at the ceramic-metal interface. CrSiON and ZrSiON interlayers enhanced ceramic-to-metal adhesion in NiCr-based dental restorations. The enhancement in bond strength is primarily ascribed to substrate bias-induced modifications in the coating's stoichiometry, roughness, and adhesion.
牙科美学需求的不断增长推动了材料和技术的重大进步。牙科修复体中陶瓷脱落的主要原因是广泛的机械应力，这常常导致脱落和临床并发症。本研究旨在通过引入生物相容性无机SiON薄膜（ = Cr或Zr）作为中间层来提高NiCr基金属框架与陶瓷涂层之间的结合强度。使用阴极电弧蒸发在NiCr合金上沉积厚度约为2μm的SiON涂层。为了调整涂层的化学计量、形态和机械性能，改变了衬底偏压：-50 V、-100 V、-150 V、-200 V。使用SEM/EDS、XRD、轮廓仪和接触角分析进行结构和表面表征。通过标准化划痕试验评估涂层附着力，同时使用三点弯曲试验评估结合强度。NiCr合金呈现树枝状微观结构，陶瓷层主要由石英、长石、高岭土和ZrO组成。与Cr基涂层相比，ZrSiON涂层表现出更好的粗糙度、元素掺入和附着力，通过增加衬底偏压，这些性能进一步得到改善。在-200 V下沉积的ZrSiON涂层获得了最高的结合强度，我们将这一结果归因于陶瓷-金属界面处表面粗糙度的增加和机械互锁。CrSiON和ZrSiON中间层增强了NiCr基牙科修复体中陶瓷与金属的附着力。结合强度的提高主要归因于衬底偏压引起的涂层化学计量、粗糙度和附着力的改变。
