Resident, Department of Dental Implant Center, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, PR China.
Graduate student, Department of Dental Implant Center, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, PR China; and Attending, Department of Prosthodontics, Changchun Stomatological Hospital, Changchun, PR China.
J Prosthet Dent. 2024 Nov;132(5):994.e1-994.e8. doi: 10.1016/j.prosdent.2024.07.015. Epub 2024 Jul 29.
The accuracy of intraoral scanning techniques for complete arch implant-supported prostheses remains unclear.
The purpose of this in vitro study was to evaluate the accuracy of complete arch intraoral scanning using newly modified scan bodies.
A definitive cast with 6 parallel dental implants (6-246 subgroup, right first molar, right first premolar, right lateral incisor, left lateral incisor, left first premolar, and left first molar) was fabricated. By masking the implants with artificial gingiva, 2 other distinct definitive casts were obtained for 2 subgroups: the 4-24 subgroup, which included 4 implants (right first premolar, right lateral incisor, left lateral incisor, and left first premolar) and the 4-26 subgroup, which also included 4 implants (right first molar, right lateral incisor, left lateral incisor, and left first molar). Three methods were used to record implant location in these 3 subgroups: conventional impression making using the open-tray splinted technique (group CNV), intraoral scanning with the use of conventional scan bodies (group IOS-C), and intraoral scanning using newly modified scan bodies (group IOS-M). To assess accuracy, the best-fit algorithm was used, and root mean square (RMS) values were calculated. Descriptive statistics, including the median, interquartile range, and minimum and maximum values, were used to summarize the variables. Accuracy among different groups was compared, and the influence of the number of implants and the scan distance on the accuracy of group IOS-M was investigated. Appropriate methods were chosen based on the examination of normal distribution and homogeneity of variance, with 1-way analysis of variance (ANOVA) and the Tukey multiple comparison test for data normally (or log-normally) distributed and having equal variances and the Brown-Forsythe ANOVA test and Dunnett T3 multiple comparisons test for data normally (or log-normally) distributed but having unequal variances (α=.05). For data that did not follow a normal or log-normal distribution, the nonparametric Kruskal-Wallis test and Dunn multiple comparisons test was used.
The trueness of group IOS-M ranged from 15.5 to 37.5 µm, with a median (Q1, Q3) of 22.8 (20.3, 25.5) μm, better than that of group IOS-C (P<.001), ranging from 10.1 to 110.0 µm, with a median (Q1, Q3) of 32.1 (26.3, 47.6) μm. Although the trueness of group IOS-M was worse than group CNV (P<.001), ranging from 6.7 to 22.5 µm, with a median (Q1, Q3) of 14.9 (10.5, 17.8) μm, it was within the threshold deemed acceptable to produce clinically suitable complete arch restorations (<59 to 72 µm). The precision of group IOS-M, ranging from 7.2 to 40.8 µm, with a median (Q1, Q3) of 19.5 (16.4, 23.0) μm, was better than that of group IOS-C (P<.001), ranging from 9.8 to 86.8 µm, with a median (Q1, Q3) of 33.7 (25.2, 44.5) μm, but not as good as group CNV (P<.001), ranging from 7.0 to 34.3 µm, with a median (Q1, Q3) of 18.8 (14.3, 21.4) μm. No significant difference in accuracy was found in group IOS-M among subgroups 6-246, 4-26, and 4-24 (P>.05).
For complete arch implant scans, the modified scan body significantly improved the accuracy of intraoral scanning, with trueness <59 to 72 µm (threshold deemed acceptable to produce clinically suitable complete arch restorations). The accuracy of intraoral scanning using the modified scan bodies was not affected by the number of implants or the scan distance.
用于全口种植体支持修复体的口内扫描技术的准确性尚不清楚。
本体外研究的目的是评估使用新修改的扫描体进行全口扫描的准确性。
制作带有 6 个平行种植体（6-246 亚组，右侧第一磨牙、右侧第一前磨牙、右侧侧切牙、左侧侧切牙、左侧第一前磨牙和左侧第一磨牙）的确定模型。通过用人工牙龈覆盖种植体，获得了另外 2 个不同的确定模型：4-24 亚组，包括 4 个种植体（右侧第一前磨牙、右侧侧切牙、左侧侧切牙和左侧第一前磨牙）和 4-26 亚组，还包括 4 个种植体（右侧第一磨牙、右侧侧切牙、左侧侧切牙和左侧第一磨牙）。使用三种方法记录这 3 个亚组中的种植体位置：常规开口托盘固定印模技术（组 CNV）、使用常规扫描体的口内扫描（组 IOS-C）和使用新修改的扫描体的口内扫描（组 IOS-M）。为了评估准确性，使用最佳拟合算法，并计算均方根（RMS）值。使用中位数、四分位距和最小值和最大值来总结变量。比较不同组之间的准确性，并研究组 IOS-M 中种植体数量和扫描距离对准确性的影响。根据正态分布和方差同质性的检验选择适当的方法，数据正态（或对数正态）分布且方差相等时采用单因素方差分析（ANOVA）和 Tukey 多重比较检验，数据正态（或对数正态）分布但方差不等时采用 Brown-Forsythe ANOVA 检验和 Dunnett T3 多重比较检验（α=.05）。对于不符合正态或对数正态分布的数据，使用非参数 Kruskal-Wallis 检验和 Dunn 多重比较检验。
组 IOS-M 的准确性范围为 15.5 至 37.5 μm，中位数（Q1，Q3）为 22.8（20.3，25.5）μm，优于组 IOS-C（P<.001），范围为 10.1 至 110.0 μm，中位数（Q1，Q3）为 32.1（26.3，47.6）μm。尽管组 IOS-M 的准确性比组 CNV（P<.001）差，范围为 6.7 至 22.5 μm，中位数（Q1，Q3）为 14.9（10.5，17.8）μm，但仍在产生临床适用的全口修复体的可接受范围内（<59 至 72 μm）。组 IOS-M 的精度范围为 7.2 至 40.8 μm，中位数（Q1，Q3）为 19.5（16.4，23.0）μm，优于组 IOS-C（P<.001），范围为 9.8 至 86.8 μm，中位数（Q1，Q3）为 33.7（25.2，44.5）μm，但不如组 CNV（P<.001），范围为 7.0 至 34.3 μm，中位数（Q1，Q3）为 18.8（14.3，21.4）μm。组 IOS-M 中在亚组 6-246、4-26 和 4-24 之间的准确性没有显著差异（P>.05）。
对于全口种植扫描，修改后的扫描体显著提高了口内扫描的准确性，准确性为<59 至 72 μm（产生临床适用的全口修复体的可接受阈值）。使用修改后的扫描体进行口内扫描的准确性不受种植体数量或扫描距离的影响。
