Shear bond strenght between different resinous cements and lithium disilicate ceramic

Abstract Introduction The success of indirect restorations depends on the union between cement and dental substrate. Therefore, the selection and knowledge of the characteristics of cement is important for the retention of indirect restoration. Objective Is to evaluate the bond strength of two different resin cements to ceramic lithium disilicate. Methodology Two experimental groups were made: conventional resin cement (CRC Group) and self-adhesive resin cement (CRA Group). With this, 10 lithium disilicate ceramics discs (10 mm) were prefabricated and on each disc were made 04 cement posts (0.7×1.0 mm), yielding a total of 20 samples of each type of cement. The disks had the same surface treatment for both groups, which is standard for the rich silica ceramic according to the protocol established by the manufacturer. The samples were submitted to microshear test to evaluate the bond strength between the cement and ceramics. Subsequently, the fail mode was analyzed in an optical microscope. Result Data were subjected to statistical analysis. It was observed that the CRC group had a higher bond strength (15.29 MPa) compared to CRA group (12.41 MPa). In the analysis of fail mode, neither samples obtained adhesive fracture. In both groups, CRC (75%) and CRA (65%) it was obtained more failures of the mixed type, followed by the cohesive failure. Conclusion Both cements showed adhesion on ceramic. The conventional resin cement showed better adherence to the ceramic base of lithium disilicate than the self-adhesive resin cement.

## 摘要
### 引言
间接修复体的成功取决于粘接剂与牙体基质的结合。因此，了解粘接剂的特性并合理选择其类型，对间接修复体的固位效果至关重要。
### 研究目的
本研究旨在评估两种不同树脂粘接剂（resin cement）与二硅酸锂陶瓷（lithium disilicate ceramic）之间的粘接强度。
### 研究方法
设置两个实验组：常规树脂粘接剂组（conventional resin cement，CRC组）与自粘接树脂粘接剂组（self-adhesive resin cement，CRA组）。预制10片直径10mm的二硅酸锂陶瓷试件，每片陶瓷表面制备4个尺寸为0.7mm×1.0mm的粘接柱，每种粘接剂对应20个样本。两组试件的陶瓷表面均按照厂商制定的标准化富硅陶瓷表面处理流程进行统一处理。随后采用微剪切试验（microshear test）检测粘接剂与陶瓷间的粘接强度，并通过光学显微镜分析试件的破坏模式。
### 研究结果
对实验数据进行统计学分析后发现，常规树脂粘接剂组的粘接强度（15.29 MPa）高于自粘接树脂粘接剂组（12.41 MPa）。破坏模式分析显示，两组试件均未出现单纯粘接性断裂；两组试件中，常规树脂粘接剂组75%、自粘接树脂粘接剂组65%的样本均以混合型破坏为主，其次为内聚性破坏。
### 研究结论
两种粘接剂均可与二硅酸锂陶瓷形成有效粘接，其中常规树脂粘接剂相较于自粘接树脂粘接剂，对二硅酸锂陶瓷基底的粘接性能更优。