Ren Shuxin, Jiang Xi, Lin Ye, Di Ping
Department of Oral Implantology, Peking University School and Hospital of Stomatology, Beijing, China.
J Prosthodont. 2022 Jun;31(5):405-411. doi: 10.1111/jopr.13447. Epub 2021 Dec 8.
This is a clinical study to compare complete digital workflows generated using intraoral scanning and the split-file technique with a conventional workflow for cement-retained implant-supported restorations.
Forty patients requiring posterior single-unit implant restorations were included. Twenty patients were randomly assigned to the complete digital workflow group, involving intraoral scanning and manufacture of cement-retained crowns using the split-file technique (test group). The remaining 20 patients were assigned to the hybrid workflow group (control group), involving conventional impressions and CAD-CAM fabricated crowns based on stone casts. Scanning of the crowns was performed before and after clinical adjustment using an intraoral scanner (TRIOS Color; 3Shape). Two 3D digital models were trimmed and superimposed to evaluate changes in dimensions using Geomagic Control 2014 software. Chair-side and laboratory times for the entire workflow were recorded. Independent-sample t tests were used for the statistical analysis.
All crowns were inserted without refabrication. The average maximum occlusal adjustment of the crowns, measured as maximum deviation of occlusal area in superimposed pre and post scans, was -212.7 ± 150.5 and -330.7 ± 192.5 µm in the test and control groups, respectively (p = 0.037). The average area of occlusal adjustment, measured as area of deviation larger than 100 µm, was 8.4 ± 8.1 and 17.1 ± 12.3 mm in the test and control groups, respectively (p = 0.012). The mesial and distal contact adjustment amounts, maximum deviations of proximal area, were -33.0 ± 96.2 and -48.6 ± 70.5 µm in the test group, and -3.7 ± 66.7 µm and -11.4 ± 106.7 µm in the control group, respectively. The mean chair-side time was 20.20 ± 3.00 and 26.65 ± 4.53 minutes in the test and control groups, respectively (p < 0.001). The mean laboratory time was 43.70 ± 5.56 and 84.55 ± 5.81 minutes in the test and control groups, respectively (p < 0.001).
Single-unit cement-retained crowns with complete digital workflows required fewer crown adjustments and had shorter clinical and laboratory times compared to conventional impressions and hybrid workflows. Digital impressions and the split-file technique provided customized abutments and cement-retained crowns, thus broadening the indications for digital workflows for implants.
本临床研究旨在比较使用口内扫描和分割文件技术生成的全数字化工作流程与传统工作流程用于粘结固位种植体支持修复体的情况。
纳入40例需要后牙单单位种植修复的患者。20例患者被随机分配至全数字化工作流程组，采用口内扫描并使用分割文件技术制作粘结固位冠（试验组）。其余20例患者被分配至混合工作流程组（对照组），采用传统印模并基于石膏模型制作CAD-CAM修复冠。使用口内扫描仪（TRIOS Color；3Shape）在临床调整前后对修复冠进行扫描。使用Geomagic Control 2014软件对两个三维数字模型进行修剪和叠加，以评估尺寸变化。记录整个工作流程的椅旁时间和实验室时间。采用独立样本t检验进行统计分析。
所有修复冠均无需重新制作即可就位。以叠加的扫描前和扫描后图像中咬合面区域的最大偏差衡量，试验组和对照组修复冠的平均最大咬合调整量分别为-212.7±150.5和-330.7±192.5µm（p = 0.037）。以偏差大于100µm的区域衡量，试验组和对照组的平均咬合调整面积分别为8.4±8.1和17.1±12.3mm²（p = 0.012）。试验组近中及远中接触调整量（近中区域的最大偏差）分别为-33.0±96.2和-48.6±70.5µm，对照组分别为-3.7±66.7µm和-11.4±106.7µm。试验组和对照组的平均椅旁时间分别为20.20±3.00和26.65±4.53分钟（p < 0.001）。试验组和对照组的平均实验室时间分别为43.70±5.56和84.55±5.81分钟（p < 0.001）。
与传统印模和混合工作流程相比，采用全数字化工作流程的单单位粘结固位冠所需的冠调整较少，临床和实验室时间较短。数字印模和分割文件技术提供了定制基台和粘结固位冠，从而拓宽了种植体数字工作流程的适应证。
