Department of Restorative and Prosthetic Dentistry, Ohio State University College of Dentistry, Columbus, Ohio, USA.
Int J Oral Maxillofac Implants. 2010 Sep-Oct;25(5):953-9.
This study aimed to analyze and compare strain distribution patterns for splinted and nonsplinted restorations for dental implants with an internal conical connection.
Two stereolithic acrylic resin models were created using computed tomographic scan data from a patient missing all mandibular molar teeth. Two implants were placed in the right side of two mandibular models using a computer-generated surgical guide and appropriate protocol. The first model received 5 x 13-mm implants, and the second received 5 x 11-mm implants. Three splinted and three nonsplinted sets of gold screw-retained prostheses were created to fit the implants on each of the two stereolithic models. The 3D image correlation technique was used for full-field measurement of strains using commercial image correlation software and a pair of high-resolution digital cameras, which provided a synchronized stereo view of the models during the experiment. Static loads of up to 203 N were applied in vertical and oblique directions. Strain distribution data were compared for major and minor strains. A mixed-models analysis of variance was done to evaluate all main effect and two-way interactions for each strain, and P values were corrected for multiple comparisons using the step-down Bonferroni adjustment.
Evidence of increased load sharing for the splinted prostheses compared to the nonsplinted prostheses was shown. Strain distribution data represented by the ratio of anterior and posterior peak strains were not statistically different for the splinted and nonsplinted prostheses for either implant length.
Splinted prostheses generated more uniform strain distributions; however, the strain distribution data were not statistically different from that seen for the nonsplinted prostheses. This suggests that splinting may not be significant for internally connected implants when the crown-to-implant ratio is less than 1. However, clinical corroboration of these findings is required.
本研究旨在分析和比较具有内部锥形连接的牙种植体修复体的应变分布模式，包括带夹板和不带夹板的修复体。
使用从一位缺失所有下颌磨牙的患者的计算机断层扫描数据创建了两个立体光刻丙烯酸树脂模型。使用计算机生成的手术导板和适当的方案，在两个下颌模型的右侧分别植入 2 个种植体。第一个模型植入 5 x 13-mm 的种植体，第二个模型植入 5 x 11-mm 的种植体。为每个立体模型创建了三个带夹板和三个不带夹板的金螺钉固位修复体。使用商用图像相关软件和一对高分辨率数字相机的 3D 图像相关技术进行全场应变测量，该技术在实验过程中为模型提供了同步的立体视图。在垂直和倾斜方向上施加高达 203 N 的静态载荷。比较主要应变和小应变的应变分布数据。使用混合模型方差分析评估每个应变的所有主要效应和双向相互作用，并使用逐步 Bonferroni 调整校正多重比较的 P 值。
与不带夹板的修复体相比，带夹板的修复体显示出了增加的负载分担证据。对于两种种植体长，夹板和不带夹板的修复体的前、后峰值应变比的应变分布数据在统计学上没有差异。
夹板修复体产生了更均匀的应变分布；然而，从统计学上看，与不带夹板的修复体相比，应变分布数据没有差异。这表明，当冠-植体比小于 1 时，内部连接的种植体可能不需要夹板。然而，需要临床证实这些发现。
