Kahnamouei Mehdi Abed, Bahari Mahmoud, Ebrahimi Chaharom Mohammad Esmaeel, Kimyai Soodabeh, Daneshpooy Mehdi, Katebi Katayoun, Elhami Bahareh
Esthetic and Restorative Dentistry, Department of Esthetic and Restorative Dentistry, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran.
Dental and Periodontal Research Center, Tabriz University of Medical Sciences, Tabriz,Iran.
Eur Oral Res. 2024 Sep 5;58(3):133-138. doi: 10.26650/eor.20231302012.
The objective of this study was to assess the impact of preheating on the microhardness and flexural strength of bulk-fill resin composites.
In this in vitro study, forty-two specimens were prepared of each composite, X-tra fil and Opus Bulk Fill, resulting in 84 disk-shaped specimens for microhardness testing and 84 bar-shaped specimens for flexural strength analysis. The specimens were divided into four groups as follows: Group 1: X-tra fil composite with preheating (at 68°C for 15 minutes), group 2: X-tra fil composite without preheating (at room temperature), group 3: Opus Bulk Fill composite with the same preheating method, group 4: Opus Bulk Fill composite without preheating. Microhardness was assessed using the Vickers test with a diamond indenter, and flexural strength was measured using a 3-point flexural test. Statistical comparisons were performed on the calculated results.
In the preheated groups, both X-tra fil and Opus Bulk Fill composites exhibited significantly higher mean flexural strength compared to the non-preheated groups (p<0.001). However, there was no significant difference in the mean microhardness between the two groups for either type of composite (p=0.719). Additionally, the mean flexural strength and microhardness of X-tra fil composite, in both preheated and non-preheated conditions, were higher than those of the Opus Bulk Fill composite (p<0.001).
Preheating bulk-fill composites to 68°C has no detrimental effect on their microhardness and increases the flexural strength of these materials. Furthermore, the degree of microhardness and flexural strength in bulk-fill composites varies between brands and is influenced by their chemical compositions.
本研究的目的是评估预热对大块充填树脂复合材料显微硬度和弯曲强度的影响。
在这项体外研究中，每种复合材料（X-tra fil和Opus Bulk Fill）制备了42个试样，共得到84个圆盘形试样用于显微硬度测试，84个条形试样用于弯曲强度分析。试样分为以下四组：第1组：预热（68°C，15分钟）的X-tra fil复合材料；第2组：未预热（室温）的X-tra fil复合材料；第3组：采用相同预热方法的Opus Bulk Fill复合材料；第4组：未预热的Opus Bulk Fill复合材料。使用带有金刚石压头的维氏试验评估显微硬度，使用三点弯曲试验测量弯曲强度。对计算结果进行统计学比较。
在预热组中，与未预热组相比，X-tra fil和Opus Bulk Fill复合材料的平均弯曲强度均显著更高（p<0.001）。然而，对于两种类型的复合材料，两组之间的平均显微硬度没有显著差异（p=0.719）。此外，无论预热与否，X-tra fil复合材料的平均弯曲强度和显微硬度均高于Opus Bulk Fill复合材料（p<0.001）。
将大块充填复合材料预热至68°C对其显微硬度没有不利影响，并提高了这些材料的弯曲强度。此外，大块充填复合材料的显微硬度和弯曲强度程度因品牌而异，并受其化学成分影响。
