Department of Operative Dentistry, University of São Paulo, School of Dentistry, Avenida Professor Lineu Prestes, 2227, São Paulo, SP 05508-000, Brazil.
Department of Dentistry, Federal University of Sergipe, Center of Biological Sciences and Health, Rua Cláudio Batista S/N, Sanatório, Aracaju, SE 49060-100, Brazil.
J Mech Behav Biomed Mater. 2019 Mar;91:309-314. doi: 10.1016/j.jmbbm.2018.12.034. Epub 2018 Dec 25.
Dental cervical restorations may be impacted by resultants of occlusal loads that may have already contributed to the development of the lesion and should rely on materials' favorable properties to bear the stresses. The marginal quality of cervical restorations made with materials of different moduli of elasticity in essence, isolated, or in combination, was evaluated relative to eccentric occlusal loading. Cervical wedge-shaped cavities, prepared in extracted premolars, were restored with a composite resin (CR), a restorative ionomer (GIC), or the composite in combination with a lining ionomer (Mixed restoration: M). Half of the teeth in each group were subjected to eccentric occlusal loading (eol; 150 N / 10 cycles / 2.5 Hz; CReol / GICeol / Meol, n = 10), and the others were stored in 37 °C distilled water (Control: c; CRc / GICc / Mc, n = 10). A fluorescein-modified adhesive favored delimitation of formed gaps, which were evaluated by confocal laser scanning microscopy regarding their presence, location related to the cavity walls, and width and depth (µm), at a 5% significance level. From a comprehensive perspective, neither the loading nor the materials were significantly associated with the qualitative response variables or exerted any influence over the quantitative variables. More specifically, the use of the different materials was significantly associated with the frequency of gaps exclusively when loading was applied (Chi-square test, p = 0.029, CR > M > GIC). Though the marginal quality of cervical restorations may not be influenced by eccentric occlusal loading or the use of different materials, even in association in general, the unfavorable aspects of the use of the composite may be relevant, particularly in face of the existence of eccentric occlusal loads.
牙颈部修复体可能会受到咬合负荷的影响，这些负荷可能已经导致了病变的发生，因此应该依靠材料的优良特性来承受这些应力。本研究旨在评估不同弹性模量材料制成的牙颈部修复体在承受偏侧咬合负荷时的边缘质量，这些材料单独或联合使用，包括复合树脂（CR）、修复离子水门汀（GIC）和复合树脂联合衬里离子水门汀（混合修复体：M）。从每个实验组的 10 颗磨牙中制备楔形牙颈部缺损，用上述三种材料修复。每组的一半样本接受偏侧咬合负荷（eol；150 N / 10 次循环 / 2.5 Hz；CReol / GICeol / Meol，n=10），另一半样本置于 37°C蒸馏水中（对照组：c；CRc / GICc / Mc，n=10）。使用荧光素改性的黏结剂有利于形成间隙的区分，通过共聚焦激光扫描显微镜观察其存在情况、与洞壁的位置关系以及宽度和深度（µm），以 5%的显著水平进行评估。从综合角度来看，无论是负荷还是材料都与定性结果变量无显著相关性，也没有对定量变量产生影响。更具体地说，当施加负荷时，不同材料的使用与间隙的发生频率显著相关（卡方检验，p=0.029，CR＞M＞GIC）。尽管牙颈部修复体的边缘质量可能不受偏侧咬合负荷或不同材料使用的影响，但在一般情况下，复合材料的不利方面可能是相关的，特别是在存在偏侧咬合负荷的情况下。
