Statement of problem

Although computer-aided design has become popular, restorations are typically designed from static occlusion and dynamically by using an average-value virtual articulator. Patient-specific motion recorded by using an intraoral scanner has rarely been used to design restorations, and its design ability has not been analyzed.

Purpose

The purpose of this clinical study was to record patient-specific motion by using an intraoral scanner and to analyze its ability to design the morphology of the wear facets on mandibular first molar crowns.

Material and methods

An intraoral scanner was used to scan complete arch digital casts and to record patient-specific motion of 11 participants. Right and left mandibular first molars were selected as the target teeth. The complete crown preparations of the target teeth were virtually prepared on the digital mandibular casts by using the Geomagic Studio 2013 software program. High points were created by elevating the wear facets of the target teeth by 0.3 mm in the occlusal direction to generate digital wax patterns. The Dental System software program was used to design crowns with the anatomic coping design method. Occlusal adjustment with static occlusion (STA crown), with the average-value virtual articulator (DYN crown), and with patient-specific motion (FUN crown) was carried out. The crowns adjusted with these 3 methods were compared with the original wear facets. The mean value and root mean square (RMS) of 3D deviation were measured. One-way ANOVA was used to analyze the influence of the occlusal surface design methods on the morphology of the wear facets (α=.05).

Results

The STA crowns had the poorest results with the mean ±standard deviation 3D deviation value of 0.15 ±0.05 mm and RMS value of 0.19 ±0.04 mm. The best results occurred in the FUN group, with the mean ±standard deviation 3D deviation value of 0.05 ±0.06 mm and RMS value of 0.13 ±0.03 mm. Significant differences were found among the 3 groups (P<.01). Except for the RMS value between the STA and DYN groups, significant differences were found between groups from the pairwise comparisons.

Conclusions

The occlusal surface of the crowns designed by using the patient-specific motion recorded with the intraoral scanner had the best coincidence with the morphology of the wear facets on the original teeth.

中文翻译：

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通过使用口腔内扫描仪的患者特定运动设计下颌第一磨牙冠的磨损面：一项临床研究

问题陈述

虽然计算机辅助设计已变得流行，但修复体通常是从静态咬合和使用平均值虚拟咬合架动态设计的。使用口内扫描仪记录的患者特定运动很少用于设计修复体，其设计能力也未被分析。

目的

本临床研究的目的是通过使用口内扫描仪记录患者的特定运动，并分析其设计下颌第一磨牙冠磨损面形态的能力。

材料与方法

使用口内扫描仪扫描完整的牙弓数字模型并记录 11 名参与者的特定患者运动。选择左右下颌第一磨牙作为目标牙。使用 Geomagic Studio 2013 软件程序在数字下颌模型上虚拟准备目标牙齿的完整牙冠预备体。通过将目标牙齿的磨损面沿咬合方向提升 0.3 毫米以生成数字蜡模来创建高点。Dental System 软件程序用于采用解剖帽设计方法设计牙冠。进行了静态咬合（STA 冠）、平均值虚拟咬合架（DYN 冠）和患者特定运动（FUN 冠）的咬合调整。将用这 3 种方法调整后的牙冠与原始磨损刻面进行比较。测量了 3D 偏差的平均值和均方根 (RMS)。使用单向方差分析分析咬合面设计方法对磨损面形态的影响 (α=.05)。

结果

STA 牙冠的结果最差，平均±标准偏差 3D 偏差值为 0.15 ±0.05 毫米，RMS 值为 0.19 ±0.04 毫米。最好的结果发生在 FUN 组，平均±标准偏差 3D 偏差值为 0.05 ±0.06 mm，RMS 值为 0.13 ±0.03 mm。3 组之间存在显着差异 ( P <.01)。除了 STA 和 DYN 组之间的 RMS 值外，从成对比较中发现组间存在显着差异。

结论

利用口内扫描仪记录的患者特定运动设计的牙冠咬合面与原牙磨损面的形态最吻合。