Wang Yujun, Millstein Philip, Lu Korina Yun-Fan, Lee Jason D, Lee Sang J
Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA 02115, USA.
Dent J (Basel). 2024 Nov 22;12(12):377. doi: 10.3390/dj12120377.
Occlusion plays a crucial role in the long-term success and functionality of dental restorations. The purpose of this study was to investigate the changes in occlusal contacts upon the cementation of zirconia crowns with different cement spacer settings in computer-aided design and computer-aided manufacturing (CAD-CAM) software (3Shape Dental System version 2.102.1.0). A master model of a prepared abutment for a crown on the right maxillary first molar was scanned, and 30 sets of sample casts and zirconia crowns were fabricated with varying cement spaces (70 μm and 120 μm). These casts were mounted in maximal intercuspation (MIP) on a semi-adjustable articulator. Pre-cementation adjustments were made to fit the crowns and maintain the existing occlusion. Occlusal records were taken before and after cementation using polyvinyl siloxane impression material. These records were analyzed using a DC light box and image analyzer to measure changes in contact area, intensity, and patterns. Paired sample t-tests were used to compare pre- and post-cementation occlusal contact areas of each sample (α = 0.05). Significant differences in occlusal contact areas were found between pre- and post-cementation in both groups ( < 0.001). The mean post-cementation contact surface area for the 70 μm group was 6281 ± 3310 μm, compared to 2339 ± 1206 μm before cementation. For the 120 μm group, the post-cementation area was 5545 ± 3491 μm, compared to 2071 ± 909 μm before cementation. An increase in contact intensity was also observed after cementation. This study demonstrates that cementation increases occlusal contact surface area and intensity in both cement space groups.
咬合在牙齿修复体的长期成功和功能发挥中起着至关重要的作用。本研究的目的是在计算机辅助设计和计算机辅助制造（CAD-CAM）软件（3Shape Dental System版本2.102.1.0）中，研究不同粘结剂间隙设置下氧化锆全冠粘结后咬合接触的变化。对上颌右侧第一磨牙预备基牙的主模型进行扫描，并制作了30组具有不同粘结剂间隙（70μm和120μm）的样本模型和氧化锆全冠。将这些模型在半可调牙合架上安装至最大牙尖交错位（MIP）。粘结前进行调整以使全冠就位并维持现有的咬合关系。使用聚乙烯基硅氧烷印模材料在粘结前后获取咬合记录。使用DC灯箱和图像分析仪对这些记录进行分析，以测量接触面积、强度和模式的变化。采用配对样本t检验比较每个样本粘结前后的咬合接触面积（α = 0.05）。两组粘结前后的咬合接触面积均存在显著差异（< 0.001）。70μm组粘结后的平均接触表面积为6281±3310μm²，而粘结前为2339±1206μm²。对于120μm组，粘结后的面积为5545±3491μm²，而粘结前为2071±909μm²。粘结后还观察到接触强度增加。本研究表明，在两个粘结剂间隙组中，粘结均增加了咬合接触表面积和强度。
