Statement of problem

Intraoral scanners (IOSs) are based on light-optical imaging methods. However, little is known about whether the ambient light in dental practices influences the accuracy and scanning time of the IOS.

Purpose

The purpose of this in vitro study was to investigate the influence of different illuminations on the accuracy of 4-unit and complete-arch scans of 6 IOSs. In addition, the required scanning time was evaluated.

Material and methods

A reference structure was attached to the first premolars (P) and second molars (M) in both quadrants (L/R) of a maxillary model. The resulting measured distances were M1-P1, M2-P2, P1-P2, and M1-M2. The investigation included 6 IOSs: TRIOS 3 (TRI), Cerec Omnicam (OC), iTero Element (ITE), CS 3600 (CS), Planmeca Emerald (EME), and GC Aadva (AAD). With each IOS, 17 scans at different illuminances (100, 500, 1000, and 5000 lux) were performed (N = 408). The precision and trueness for all distances were determined, and the scanning time was recorded. For statistical analyses, the Levene tests (precision) and 1-way analysis of variance with the post hoc Tukey honestly significant difference and Games-Howell tests (trueness) were calculated.

Results

Illuminance significantly influenced the trueness of 4-unit scans for OC, EME, and AAD. TRI, OC, ITE, and CS demonstrated comparable results. AAD (>96 ±22 μm; 1000 lux) and EME (>248 ±88 μm; 500 lux) revealed greater deviations. For complete-arch scans, illuminance did not influence TRI and AAD, but significant variations were detected for ITE, CS, EME, and AAD. The least deviations were achieved with TRI and OC. The scanning time was extended for all IOSs except ITE at more than 500 lux. The shortest scanning times with OC and EME were recorded at 100 lux; with TRI, CS, and AAD at 500 lux; and with ITE at both 100 and 5000 lux. At all illuminances, the fastest scans were obtained with TRI.

Conclusions

Ambient light was found to influence the accuracy and scanning time of IOSs. This influence varies depending on the device. For 4-unit scans, the effect was not clinically relevant, but for complete-arch scans, accuracy and scanning time can be improved with appropriate lighting.

中文翻译：

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环境光是否会影响口内扫描的准确性和扫描时间？

问题陈述

口内扫描仪 (IOS) 基于光光学成像方法。然而，关于牙科诊所中的环境光是否会影响 IOS 的准确性和扫描时间知之甚少。

目的

这项体外研究的目的是研究不同光照对 6 个 IOS 的 4 单位和完整牙弓扫描准确性的影响。此外，还评估了所需的扫描时间。

材料与方法

参考结构连接到上颌模型的两个象限 (L/R) 中的第一前磨牙 (P) 和第二磨牙 (M)。得到的测量距离为 M1-P1、M2-P2、P1-P2 和 M1-M2。调查包括 6 个 IOS：TRIOS 3 (TRI)、Cerec Omnicam (OC)、iTero Element (ITE)、CS 3600 (CS)、Planmeca Emerald (EME) 和 GC Aadva (AAD)。对于每个 IOS，在不同照度（100、500、1000 和 5000 勒克斯）下进行了 17 次扫描（N = 408）。确定所有距离的精度和正确度，并记录扫描时间。对于统计分析，计算了 Levene 检验（精度）和具有事后 Tukey 诚实显着差异和 Games-Howell 检验（真实性）的单向方差分析。

结果

照度显着影响 OC、EME 和 AAD 4 单位扫描的真实性。TRI、OC、ITE 和 CS 表现出类似的结果。AAD (>96 ±22 μm; 1000 lux) 和 EME (>248 ±88 μm; 500 lux) 显示出更大的偏差。对于全弓扫描，照度不影响 TRI 和 AAD，但检测到 ITE、CS、EME 和 AAD 的显着变化。TRI 和 OC 的偏差最小。除 ITE 外，所有 IOS 的扫描时间都延长了 500 lux 以上。OC 和 EME 的最短扫描时间记录为 100 lux；TRI、CS 和 AAD 在 500 勒克斯下；和 ITE 在 100 和 5000 勒克斯。在所有照度下，使用 TRI 获得最快的扫描。

结论

发现环境光会影响 IOS 的准确性和扫描时间。这种影响因设备而异。对于 4 单位扫描，效果与临床无关，但对于完整牙弓扫描，通过适当的照明可以提高准确性和扫描时间。