Department of Biomedical and Neuromotor Science (DIBINEM), Alma Mater University of Bologna, via S. Vitale 59, 40125, Bologna, Italy.
Division of Fixed Prosthodontics and Biomaterials, University Clinics for Dental Medicine, University of Geneva, Geneva, Switzerland.
J Dent. 2024 Sep;148:105231. doi: 10.1016/j.jdent.2024.105231. Epub 2024 Jul 21.
This study aimed to assess the seating accuracy of resin composite CAD/CAM overlay restorations, employing various preparation designs and luting materials (pre-heated composite (HC) or resin cement (RC)).
A human molar's STL file was utilized to create 100 3D-printed resin tooth replicas, randomly distributed into 5 groups (n = 20) based on finishing line preparation designs: 1) Rounded shoulder above the dental equator - DE (SA); 2) Chamfer above the DE (CA); 3) Butt joint above the DE (BJ); 4) Rounded shoulder below the DE (SB); 5) Chamfer below the DE (CB). Digital impressions were acquired for all replicas, and restorations milled using Tetric CAD (Ivoclar Vivadent). The restorations were luted with HC (Tetric Prime, Ivoclar Vivadent) or RC (RelyX Universal, 3 M). Seating accuracy was evaluated through digital scans during try-in without any luting agent and post-cementation using a 3D analysis software (Geomagic wrap, 3D Systems). Data were statistically analyzed using Two-Way ANOVA (p < 0.05).
The type of luting material (RC vs HC), preparation design, and their interactions significantly impacted 3D seating of the restorations (p < 0.001). HC exhibited higer volumetric increase than RC. BJ and CA designs consistently demonstrated superior seating accuracy, irrespective of the luting material used.
The utilization of pre-heated composite resin could negatively influence the seating of overlay restorations, probably due to its higher viscosity when compared to the resin cement. However, when HC is selected as luting agent, preparation designs lacking internal angles are recommended for enhancing the precision of overlays seating.
本研究旨在评估采用不同预备设计和粘固材料（预热复合树脂（HC）或树脂水门汀（RC））制作树脂复合 CAD/CAM 贴面修复体的就位准确性。
使用 STL 文件构建了 100 个 3D 打印树脂牙模型，随机分为 5 组（n=20），根据边缘线预备设计：1）牙赤道上方的圆肩形肩台（SA）；2）牙赤道上方的肩台（CA）；3）牙赤道上方的对接肩台（BJ）；4）牙赤道下方的圆肩形肩台（SB）；5）牙赤道下方的肩台（CB）。对所有模型进行数字印模，使用 Tetric CAD（义获嘉伟瓦登特）制作修复体。使用 HC（Tetric Prime，义获嘉伟瓦登特）或 RC（RelyX Universal，3M）粘固修复体。在没有任何粘固剂的试戴过程中和粘固后使用 3D 分析软件（Geomagic wrap，3D Systems）进行数字化扫描评估就位准确性。使用双向方差分析（p<0.05）进行统计学分析。
粘固材料类型（RC 与 HC）、预备设计及其相互作用显著影响修复体的 3D 就位（p<0.001）。HC 表现出比 RC 更高的体积增加。BJ 和 CA 设计始终表现出更好的就位准确性，与使用的粘固材料无关。
使用预热复合树脂可能会对贴面修复体的就位产生负面影响，可能是因为与树脂水门汀相比，其具有更高的粘度。然而，当选择 HC 作为粘固剂时，建议使用缺乏内部角度的预备设计，以提高贴面就位的精度。
