CLINICAL MARGINAL FIT AND PATIENT'S PREFERENCES IN IMPRESSION TECHNIQUE USING DIGITAL INTRAORAL SCANNER VERSUS POLYVINYLSILOXANE MATERIAL

Abstract

Objective: The purpose of this in vivo study was to compare the clinical marginal fit of monolithic zirconia crowns and patients’ preferences using digital impressions versus polyvinyl siloxane (PVS) impressions. Materials and Methods: Sixteen participants with indications for single molar crowns were included. After crown preparation, digital impressions by intraoral scanner (3M True Definition Scanner; 3M ESPE) and PVS impression (full-arch stock tray, Express; 3M ESPE) were made. The patients were asked to complete a 6-item questionnaire with a visual analog scale (VAS) related to perceptions of each of the following topics: time involved, taste/smell, bite registration, size of impression tray/scanner head, gag reflex, and overall preference. CAD/CAM monolithic zirconia crowns (Lava Plus High Translucency Zirconia; 3M ESPE) were fabricated from both impressions. The crowns were tried, and silicone replicas were made for clinical marginal gap measurements on 4 sides (mesial, buccal, distal, and lingual) under a steromicroscope 3 times by blinded examiner. Intra-examiner reliability was evaluated by calculating the intraclass correlation coefficient (ICC). Data on patients’ preferences and marginal gaps were analyzed by Wilcoxon’s signed-rank test. All of the analyses were performed using a 95% confidence level. Results: VAS scores for digital impressions were statistically significant higher than those for PVS impressions in every topic (P<.05). The results showed excellent reliability of the examiner with an ICC of .996. There was no significant difference between marginal gap widths between the PVS group and the digital group on all sides (P>.05). Conclusion: There was no difference in the clinical marginal fit of zirconia crowns fabricated from either digital impressions or PVS impressions. Furthermore, patients’ satisfaction with digital impressions was significantly higher than with conventional impressions.