Elhamrawy Abdelaziz, Ramadan Hussein, Hamza Tamer
Department of Crown and Bridge, Faculty of Dental Medicine, Al-Azhar University, Cairo.
Dean of the Faculty of Dentistry, Badr University, Cairo.
J Dent Res Dent Clin Dent Prospects. 2024 Fall;18(4):242-248. doi: 10.34172/joddd.41124. Epub 2024 Dec 14.
The wear resistance of lithium disilicate glass ceramics remains inadequately understood. Therefore, the primary objective of this in vitro study was to digitally assess the wear characteristics of lithium disilicate and zirconia-reinforced lithium disilicate pressable ceramics following chewing simulation.
Twenty-two onlay ceramic restorations were fabricated on epoxy dies replicated from the maxillary first premolar ivory tooth master die. The onlay samples were randomly allocated to two equal groups (n=11) based on the material used: group L (lithium disilicate [IPS e.max Press]) and group Z (zirconia-reinforced lithium disilicate [Vita Ambria]). Self-adhesive resin cement was used to cement all of the samples. Each sample was occluded with the buccal cusps of healthy human upper first premolar teeth (n=22). Subsequently, all the samples were scanned using an intraoral scanner (Medit i500) at baseline and after chewing simulation. The acquired standard tessellation language (STL) files of baseline and post-chewing simulation data were superimposed, and the volumetric loss (mm) and wear depth (μm) of the materials and their enamel antagonists were calculated. Statistical analysis was performed using independent t-test (=0.05).
There was no statistically significant difference in the wear behavior of Vita Ambria compared to IPS e.max (<0.05). Similarly, there was no statistically significant difference in the wear behavior of their enamel antagonists (<0.05).
IPS e.max Press and Vita Ambria ceramics demonstrated comparable wear behavior.
二硅酸锂玻璃陶瓷的耐磨性仍未得到充分了解。因此，本体外研究的主要目的是在咀嚼模拟后，通过数字方式评估二硅酸锂和氧化锆增强的二硅酸锂可压铸陶瓷的磨损特性。
在从上颌第一前磨牙象牙母模复制的环氧树脂模具上制作22个嵌体陶瓷修复体。根据所用材料，将嵌体样本随机分为两组，每组11个：L组（二硅酸锂[IPS e.max Press]）和Z组（氧化锆增强的二硅酸锂[Vita Ambria]）。使用自粘树脂水门汀粘结所有样本。每个样本与健康人上颌第一前磨牙的颊尖咬合（n = 22）。随后，在基线和咀嚼模拟后，使用口腔内扫描仪（Medit i500）对所有样本进行扫描。将获取的基线和咀嚼模拟后数据的标准镶嵌语言（STL）文件进行叠加，并计算材料及其釉质对抗物的体积损失（mm）和磨损深度（μm）。使用独立t检验进行统计分析（= 0.05）。
与IPS e.max相比，Vita Ambria的磨损行为无统计学显著差异（<0.05）。同样，其釉质对抗物的磨损行为也无统计学显著差异（<0.05）。
IPS e.max Press和Vita Ambria陶瓷表现出相似的磨损行为。
