Statement of problem

Photogrammetry has been reported to be a reliable digital alternative for recording implant positions; however, the factors that may impact the accuracy of photogrammetry techniques remain unknown.

Purpose

The purpose of this in vitro study was to assess the influence of the implant reference on the accuracy of complete arch implant scans acquired by using a photogrammetry system.

Material and methods

An edentulous cast with 6 implant abutment analogs (MultiUnit Abutment Plus Replica) was obtained and digitized by using a laboratory scanner (T710; Medit). A photogrammetry system (PIC System) was selected to obtain complete arch implant scans. An optical marker (PIC Transfer, HC MUA Metal; PIC Dental) was positioned on each implant abutment of the reference cast. Each optical marker code and position was determined in the photogrammetry software program. Three groups were created based on the implant reference selected before acquiring the photogrammetry scans: right first molar (IPR-3 group), left canine (IPR-11 group), and left first molar (IPR-14 group) (n=30). Euclidean linear and angular measurements were obtained on the digitized reference cast and used to compare the discrepancies with the same measurements obtained on each experimental scan. One-way ANOVA and the Tukey tests were used to analyze the trueness data. The Levene test was used to analyze the precision values (α=.05 for all tests).

Results

One-way ANOVA revealed significant linear (P=.003) and angular (P=.009) trueness differences among the groups tested. Additionally, the Tukey test showed that the IPR-11 and IPR-14 groups had significantly different linear (P<.001) and angular trueness (P<.001). The Levene test showed no significant precision linear (P=.197) and angular (P=.235) discrepancies among the groups tested. The IPR-3 group obtained the highest trueness (P<.001) and precision (P<.001) values among the groups tested.

Conclusions

Implant reference impacted the accuracy of complete arch implant scans obtained by using the photogrammetry system tested. However, a trueness ±precision linear discrepancy of 6 ±3 µm and an angular discrepancy of 0.01 ±0.01 degrees were measured among the groups tested; therefore, the impact of the discrepancy measured should not be clinically significant.

中文翻译：

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种植体参考对使用摄影测量系统捕获的完整牙弓种植体扫描的扫描精度的影响

问题陈述

据报道，摄影测量是记录种植体位置的可靠数字替代方案。然而，可能影响摄影测量技术准确性的因素仍然未知。

目的

这项体外研究的目的是评估种植体参考对使用摄影测量系统获得的完整牙弓种植体扫描准确性的影响。

材料与方法

使用实验室扫描仪（T710；Medit）获得具有 6 个种植体基台类似物（MultiUnit Abutment Plus Replica）的无牙颌模型并进行数字化。选择摄影测量系统（PIC 系统）来获得完整的牙弓植入物扫描。将光学标记（PIC Transfer、HC MUA Metal；PIC Dental）定位在参考模型的每个种植体基台上。每个光学标记代码和位置均在摄影测量软件程序中确定。根据在获取摄影测量扫描之前选择的种植体参考创建三组：右侧第一磨牙（IPR-3 组）、左侧尖牙（IPR-11 组）和左侧第一磨牙（IPR-14 组）（n=30） 。在数字化参考铸件上获得欧几里德线性和角度测量值，并用于将差异与每次实验扫描中获得的相同测量值进行比较。使用单向方差分析和 Tukey 检验来分析真实性数据。Levene 检验用于分析精度值（所有检验的 α=.05）。

结果

单向方差分析显示测试组之间存在显着的线性 ( P =.003) 和角度 ( P =.009) 真实性差异。此外，Tukey 检验显示 IPR-11 和 IPR-14 组的线性准确度 ( P <.001) 和角度准确度 ( P <.001) 存在显着差异。Levene 检验显示，测试组之间没有显着的线性精度 ( P = .197) 和角度精度 ( P = .235) 差异。在测试组中，IPR-3 组获得了最高的正确度 ( P <.001) 和精确度 ( P <.001) 值。

结论

种植体参考影响通过使用测试的摄影测量系统获得的完整牙弓种植体扫描的准确性。然而，测试组之间测得的真实度±精度线性差异为 6 ±3 µm，角度差异为 0.01 ±0.01 度；因此，所测量的差异的影响不应具有临床显着性。