Al-Akhali Majed, Chaar Mohamed Sad, Elsayed Adham, Samran Abdulaziz, Kern Matthias
Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University, Kiel, Germany; Department of prosthodontics, School of Dentistry, Ibb University, Ibb, Yemen.
Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University, Kiel, Germany.
J Mech Behav Biomed Mater. 2017 Oct;74:245-250. doi: 10.1016/j.jmbbm.2017.06.013. Epub 2017 Jun 13.
The purpose of this in vitro study was to evaluate the influence of thermodynamic loading on the durability and fracture resistance behavior of occlusal veneers fabricated from different biomedical dental CAD/CAM materials.
The occlusal surfaces of 64 extracted premolars were prepared in the enamel layer and restored with occlusal veneers with a fissure/cusp thickness of 0.5/0.8mm made from four different dental CAD/CAM materials: group LD lithium disilicate (e.max CAD), group LS zirconia-reinforced lithium silicate (Vita Suprinity), group PI polymer-infiltrated ceramic (Vita Enamic), and group PM polymethylmethacrylate PMMA (Telio CAD). The prepared teeth were etched with phosphoric acid. The occlusal veneers were then bonded using an adhesive luting system (Multilink Primer A/B and Multilink Automix luting resin). Half of the specimens were subjected to thermodynamic loading in a chewing simulator (1.2 million cycles at 98N). All specimens were quasi-statically loaded until fracture. The statistical analysis was made using the t-test and one-way ANOVA followed by the Tukey HSD test (α = 0.05).
All aged specimens survived the thermodynamic loading. Thermodynamic loading significantly raised the fracture resistance in groups LS, PI, and PM (P < 0.03). Occlusal veneers made from lithium disilicate and zirconia-reinforced lithium silicate recorded higher fracture resistance than those made from polymer-infiltrated ceramic and PMMA resin.
All tested dental CAD/CAM biomaterials exhibited a fracture resistance considerably exceeding the average occlusal force in the posterior dentition. Therefore, they might present a viable long-term treatment for restoring the occlusal surfaces of posterior teeth.
本体外研究的目的是评估热力学加载对由不同生物医学牙科CAD/CAM材料制成的咬合贴面的耐久性和抗断裂性能的影响。
对64颗拔除的前磨牙的咬合面在釉质层进行制备，并用由四种不同牙科CAD/CAM材料制成的裂隙/牙尖厚度为0.5/0.8mm的咬合贴面进行修复：LD组为二硅酸锂（e.max CAD），LS组为氧化锆增强硅酸锂（Vita Suprinity），PI组为聚合物渗透陶瓷（Vita Enamic），PM组为聚甲基丙烯酸甲酯（PMMA，Telio CAD）。制备好的牙齿用磷酸蚀刻。然后使用粘结剂粘结系统（Multilink Primer A/B和Multilink Automix粘结树脂）粘结咬合贴面。一半的标本在咀嚼模拟器中进行热力学加载（98N下120万次循环）。所有标本均进行准静态加载直至断裂。使用t检验和单因素方差分析，随后进行Tukey HSD检验（α = 0.05）进行统计分析。
所有老化标本均在热力学加载中存活。热力学加载显著提高了LS组、PI组和PM组的抗断裂性（P < 0.03）。由二硅酸锂和氧化锆增强硅酸锂制成的咬合贴面的抗断裂性高于由聚合物渗透陶瓷和PMMA树脂制成的咬合贴面。
所有测试的牙科CAD/CAM生物材料的抗断裂性均大大超过后牙列的平均咬合力。因此，它们可能是修复后牙咬合面的可行长期治疗方法。
