Abu-Obaid Ala'a
Department of Prosthetic Dental Sciences, Collage of Dentistry, King Saud University, Riyadh, Saudi Arabia.
Saudi Dent J. 2024 Sep;36(9):1203-1208. doi: 10.1016/j.sdentj.2024.06.018. Epub 2024 Jun 13.
To assess the amount of excess cement and the retentive strengths of two different cementation techniques (conventional cementation and practice abutment) using copings fabricated with three different cement thicknesses (20 μm, 35 μm, and 50 μm).
Thirty zirconia copings were fabricated on screw retained abutments and randomly divided into three equal groups (n = 10) according to the cement thickness (20 μm, 35 μm, and 50 μm). Each group was cemented with tow cementation techniques. Cementation was performed with provisional cement (Temp-Bond). In the conventional cementation technique, cement was applied until each coping was approximately half filled, and the copings were subsequently placed on the implant-abutment assembly. Then, the copings were cleaned and cemented using the practice abutment cementation technique to remove excess cement prior to the process. Each technique was performed using copings with three different cement thicknesses (20 μm, 35 μm, and 50 μm). The specimens with the cemented copings were weighed on a high-precision analytical balance before and after removing the extruded cement, and the differences between the two measurements were calculated. Then, each specimen was subjected to a pullout test using a universal testing machine. The load required to dislodge the coping was recorded. The data were analyzed using two-way and one-way analysis of variance and independent sample t tests at a significance level of 0.05.
The highest retention values were obtained for 20 μm cement thickness in the conventional technique and the practice abutment cementation technique. The amount of excess cement was the highest for the 50 μm cement thickness obtained for both cementation techniques, whereas the lowest mean values were recorded for the 20 μm cement thickness.
The conventional cementation technique is recommended over the practice abutment technique to increase the retention of crowns cemented with provisional cement. However, care must be taken to remove the extruded cement. A cement thickness of 20 μm is preferable for enhancing the retention of cemented crowns and for reducing the amount of excess cement when applying both conventional and practical abutment cementation approaches.
使用三种不同水泥厚度（20μm、35μm和50μm）制作的全冠，评估两种不同粘结技术（传统粘结和练习基台粘结）的多余粘固剂用量及固位强度。
在螺丝固位基台上制作30个氧化锆全冠，并根据粘固剂厚度（20μm、35μm和50μm）随机分为三个相等的组（n = 10）。每组采用两种粘结技术进行粘结。使用临时粘固剂（Temp - Bond）进行粘结。在传统粘结技术中，在每个全冠约半满时涂抹粘固剂，随后将全冠放置在种植体 - 基台组件上。然后，在该过程之前，使用练习基台粘结技术对全冠进行清洁并粘结以去除多余的粘固剂。每种技术均使用三种不同粘固剂厚度（20μm、35μm和50μm）的全冠进行。在去除挤出的粘固剂之前和之后，使用高精度分析天平对带有粘结全冠的标本进行称重，并计算两次测量之间的差异。然后，使用万能试验机对每个标本进行拔出试验。记录使全冠脱位所需的载荷。使用双向和单向方差分析以及独立样本t检验在显著性水平为0.05下对数据进行分析。
在传统技术和练习基台粘结技术中，20μm的粘固剂厚度获得了最高的固位值。两种粘结技术中，50μm粘固剂厚度的多余粘固剂用量最高，而20μm粘固剂厚度的平均值最低。
为提高用临时粘固剂粘结的全冠的固位力，推荐传统粘结技术而非练习基台技术。然而，必须注意去除挤出的粘固剂。当应用传统和练习基台粘结方法时，20μm的粘固剂厚度对于提高粘结全冠的固位力和减少多余粘固剂用量更为可取。
