Affiliate Faculty, Graduate Prosthodontics, Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Wash, USA; Director of Research and Digital Dentistry, Kois Center, Seattle, Wash, USA; Affiliate Faculty, Graduate Prosthodontics, Department of Prosthodontics, School of Dental Medicine, Tufts University, Boston, MA, USA.
Private Practice, Dallas, TX, USA.
J Dent. 2022 May;120:104114. doi: 10.1016/j.jdent.2022.104114. Epub 2022 Mar 28.
To analyze the influence of the restorative material type (definitive and interim) and its surface treatment (polished or glazed) on the scanning accuracy of an intraoral scanner.
A mandibular dental typodont containing 3 typodont teeth (left second premolar and left first and second molars) was used for testing. Ten groups were created based on the crown material: typodont tooth (control group), gold (G group), zirconia (Z group), lithium disilicate (LD group), hybrid ceramic (HC group), composite resin (CR group), conventional PMMA (CNV-PMMA group), bis-acryl composite resin (CNV-BA group), milled PMMA (M-PMMA group), and additively manufactured bis-acryl-based polymer (AM-BA group). Except the G group, groups were subdivided into polished (P subgroups) or glazed (G subgroups). Each specimen was digitized by using an extraoral scanner (D1000; 3Shape A/G) and an intraoral scanner (TRIOS 4; 3Shape). Each reference scan was used to measure the discrepancy with the corresponding 15 intraoral scans by calculating the root mean square (RMS) error (Geomagic; 3D Systems). The Welch ANOVA and Games-Howell tests were selected to examine trueness (α=0.05). The F-test with Bonferroni correction was used to evaluate precision.
Significant trueness and precision differences were found (P<.001). The G-P subgroup had the lowest trueness values, while the CNV-PMMA-P, M-PMMA-P, and AM-BA-P subgroups had the highest trueness values. Significant RMS mean discrepancies were computed when comparing polished and glazed specimens fabricated with the same material (P<.001). The CNV-PMMA-G subgroup had the lowest precision values, while the CNV-BA-P subgroup had the highest precision values (P<.001).
The type and surface finishing of the restorative materials tested influenced the scanning accuracy of the IOS tested. The lowest trueness values were found in the high noble alloy specimens, while the highest trueness values were measured in conventional and milled PMMA and additively manufactured bis-acryl-based polymer polished specimens. Except for zirconia crowns, higher trueness values were found in polished specimens when compared with glazed crowns. The CNV-PMMA-G subgroup had the lowest precision values, while the highest precision values were measured in the CNV-BA-P subgroup.
Definitive and interim materials tested decrease intraoral scanning accuracy. Furthermore, polishing instead of glazing definitive and interim material assessed might be preferable to maximize intraoral scanning accuracy.
分析修复材料类型（永久性和临时性）及其表面处理（抛光或上釉）对口腔内扫描仪扫描精度的影响。
使用包含 3 颗牙模型牙（左侧第二前磨牙和左侧第一、第二磨牙）的下颌牙科模型牙进行测试。根据冠材料创建了 10 组：模型牙（对照组）、金（G 组）、氧化锆（Z 组）、锂二硅酸酯（LD 组）、混合陶瓷（HC 组）、复合树脂（CR 组）、传统聚甲基丙烯酸甲酯（CNV-PMMA 组）、双丙烯酸复合树脂（CNV-BA 组）、铣削 PMMA（M-PMMA 组）和增材制造的双丙烯酸基聚合物（AM-BA 组）。除 G 组外，各组还分为抛光（P 亚组）或上釉（G 亚组）。使用口腔外扫描仪（D1000；3Shape A/G）和口腔内扫描仪（TRIOS 4；3Shape）对每个样本进行数字化。每个参考扫描都用于通过计算均方根（RMS）误差（Geomagic；3D Systems）来测量与相应的 15 个口腔内扫描的差异。选择 Welch ANOVA 和 Games-Howell 检验来检查准确性（α=0.05）。使用 F 检验和 Bonferroni 校正来评估精度。
发现准确性和精度有显著差异（P<.001）。G-P 亚组的准确性值最低，而 CNV-PMMA-P、M-PMMA-P 和 AM-BA-P 亚组的准确性值最高。比较使用相同材料制作的抛光和上釉标本时，计算出显著的 RMS 平均差异（P<.001）。CNV-PMMA-G 亚组的精度值最低，而 CNV-BA-P 亚组的精度值最高（P<.001）。
测试的修复材料的类型和表面处理方式会影响 IOS 的扫描精度。高贵金属合金标本的准确性值最低，而传统和铣削 PMMA 和增材制造的双丙烯酸基聚合物抛光标本的准确性值最高。除氧化锆冠外，与上釉冠相比，抛光冠的准确性值更高。CNV-PMMA-G 亚组的精度值最低，而 CNV-BA-P 亚组的精度值最高。
永久性和临时性材料会降低口腔内扫描的准确性。此外，为了最大限度地提高口腔内扫描的准确性，对永久性和临时性材料进行抛光而不是上釉可能更为可取。
