Graduate student, Esthetic Restorative and Implant Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
Associate Professor and Program Director, Esthetic Restorative and Implant Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
J Prosthet Dent. 2017 Sep;118(3):386-391. doi: 10.1016/j.prosdent.2016.10.019. Epub 2017 Feb 17.
The use of digital intraoral scanners is increasing; however, evidence of its precision in making crown impressions clinically remains scarce. Patients should also feel more comfortable with digital impressions, but only a few studies evaluating this subject have been performed.
The purpose of this clinical study was to evaluate the marginal fit of monolithic zirconia crowns and patients' preferences for digital impressions versus polyvinyl siloxane (PVS) impressions.
Sixteen participants with indications for single molar crowns were included. After crown preparation, digital impressions by intraoral scanner and PVS impressions were made. The participants were asked to complete a 6-item questionnaire with a visual analog scale related to perceptions of each of the following topics: time involved, taste/smell, occlusal registration, size of impression tray/scanner, gag reflex, and overall preference. Computer-aided design and computer-aided manufacturing monolithic zirconia crowns were fabricated from both impressions. The crowns were evaluated intraorally, and a blinded examiner measured the marginal discrepancy of silicone replicas under a stereomicroscope. Intraexaminer reliability was evaluated by calculating the intraclass correlation coefficient. Data for patients' preferences and marginal discrepancies were analyzed using the paired t test (α=.05).
Visual analog scale scores for digital impressions were statistically significantly higher than those for PVS impressions in every topic (P<.05), except for occlusal registration. The results showed excellent reliability of the examiner with an intraclass correlation coefficient of .996. No significant difference was found in marginal discrepancies between the PVS group and the digital group on all sides (P>.05).
No differences were found in the clinical marginal fit of zirconia crowns fabricated from either digital impressions compared with PVS impressions. Furthermore, patients' satisfaction with digital impressions was significantly higher than with conventional impressions.
数字化口内扫描仪的使用正在增加；然而，其在临床制取牙冠印模方面的精确性的证据仍然很少。患者也应该对数字化印模感到更舒适，但只有少数评估这一主题的研究。
本临床研究的目的是评估整体氧化锆牙冠的边缘适合性以及患者对数字化印模与聚硅氧烷（PVS）印模的偏好。
纳入 16 名有单磨牙牙冠修复指征的参与者。牙冠预备后，使用口内扫描仪和 PVS 进行数字化印模。要求参与者完成一份包含 6 个项目的问卷，每个项目都与以下主题的感知相关，采用视觉模拟量表进行评估：所涉及的时间、味道/气味、咬合记录、印模托盘/扫描仪的大小、恶心反射和总体偏好。使用两种印模制作计算机辅助设计和计算机辅助制造的整体氧化锆牙冠。在口腔内评估牙冠，并由一名经过盲法的检查者在立体显微镜下测量硅橡胶代型的边缘差异。通过计算组内相关系数评估检查者的内一致性。使用配对 t 检验（α=.05）分析患者偏好和边缘差异的数据。
在每个主题（P<.05），除了咬合记录外，数字化印模的视觉模拟量表评分均显著高于 PVS 印模。结果表明，检查者的可靠性非常高，组内相关系数为.996。在所有侧面，PVS 组和数字组之间的边缘差异均无统计学差异（P>.05）。
数字化印模和 PVS 印模制取的氧化锆牙冠在临床边缘适合性方面没有差异。此外，患者对数字化印模的满意度明显高于传统印模。
