Han Jin-Won, Han Jin-Woo, Pyo Se-Wook, Kim Sunjai
Former Graduate student, Yonsei University College of Dentistry, Seoul, Republic of Korea.
Graduate student, Yonsei University College of Dentistry, Seoul, Republic of Korea.
J Prosthet Dent. 2023 Dec 21. doi: 10.1016/j.prosdent.2023.11.025.
Although the emergence angle has been related to marginal bone loss, information regarding the relationship between the transmucosal configuration of a computer-aided design and computer-aided manufacturing (CAD-CAM) abutment at specific subgingival levels and the amount of marginal bone loss is lacking.
The purpose of this retrospective clinical study was to evaluate the influence of CAD-CAM abutment profile angles, measured at different subgingival positions, on the marginal bone loss of posterior single-tooth implant-supported restorations.
A total of 260 posterior single-tooth implant-supported restorations using CAD-CAM abutments were analyzed in 206 patients. All implants had internal conical seal connections with a platform-switched design. The following data were extracted using digital periapical radiography: emergence profile, profile angle at distance ranges of 0 to 1 mm, 1 to 2 mm, and 2 to 3 mm from the implant-abutment junction, and peri-implant marginal bone loss (MBL). The MBL was measured from the time of delivery of the restorations up to 7 years or more. A linear mixed model was applied to investigate whether there was a significant difference in MBL based on the emergence profile and time, followed by the Bonferroni correction post hoc test. A Pearson correlation analysis was used to analyze the correlation between the profile angle and MBL at each distance range. The cut-off points for each distance range were determined by using the c-index, and independent t tests were conducted based on these cut-off values to evaluate the statistical differences (α=.05 for all statistical analyses).
The convex emergence profile exhibited greater MBL than the concave and straight profiles at each follow-up visit (P<.001). A significant correlation was found between the profile angle and MBL in the 0 to 1 mm, 1 to 2 mm distance ranges. However, no significant correlation was found between the profile angle and MBL in the 2 to 3 mm distance range (P>.05). The cut-off points were 34 degrees at the mesial and 28 degrees at the distal in the 0 to 1 mm range, and 33 and 20 degrees at the mesial and distal in the 1 to 2 mm range.
The profile angle near the implant-abutment junction and the type of emergence profile of the CAD-CAM abutment were closely associated with MBL in implants with internal conical seal connection with a platform switch design.
尽管穿龈角度与边缘骨吸收有关，但关于计算机辅助设计与计算机辅助制造（CAD-CAM）基台在特定龈下水平的穿黏膜形态与边缘骨吸收量之间的关系，目前仍缺乏相关信息。
本回顾性临床研究的目的是评估在不同龈下位置测量的CAD-CAM基台轮廓角度对后牙单颗种植体支持修复体边缘骨吸收的影响。
对206例患者中总共260个使用CAD-CAM基台的后牙单颗种植体支持修复体进行了分析。所有种植体均采用内部锥形密封连接和平台转换设计。使用数字化根尖片提取以下数据：穿龈轮廓、距种植体-基台连接处0至1mm、1至2mm和2至3mm距离范围内的轮廓角度，以及种植体周围边缘骨吸收（MBL）。MBL从修复体交付时开始测量，最长达7年或更长时间。应用线性混合模型研究基于穿龈轮廓和时间的MBL是否存在显著差异，随后进行Bonferroni校正的事后检验。采用Pearson相关分析来分析每个距离范围内轮廓角度与MBL之间的相关性。使用c指数确定每个距离范围的截断点，并基于这些截断值进行独立t检验以评估统计学差异（所有统计分析的α = 0.05）。
在每次随访中，凸形穿龈轮廓的MBL均高于凹形和直线形轮廓（P < 0.001）。在0至1mm、1至2mm距离范围内，轮廓角度与MBL之间存在显著相关性。然而，在2至3mm距离范围内，轮廓角度与MBL之间未发现显著相关性（P > .05）。在0至1mm范围内，近中截断点为34度，远中为28度；在1至2mm范围内，近中为33度，远中为20度。
对于采用内部锥形密封连接和平台转换设计的种植体，种植体-基台连接处附近的轮廓角度以及CAD-CAM基台的穿龈轮廓类型与MBL密切相关。
