Title: 3529 - Edentulous Jaw Impression Techniques: An In Vivo Comparison of Trueness
Najla Chebib (Presenter)
University Clinics of Dental Medicine, University of Geneva
Nicole Kalberer, University Clinics of Dental Medicine, University of Geneva
Murali Srinivasan, University Clinics of Dental Medicine, University of Geneva
Sabrina Maniewicz, University Clinics of Dental Medicine, University of Geneva
Thomas Perneger, Geneva University Hospitals
Frauke Müller, University Clinics of Dental Medicine, University of Geneva
Objectives: This study compared the trueness of edentulous jaw impressions taken with, alginate (ALG), polyvinyl siloxane (PVS), PVS modified (PVSM) with zinc-oxide eugenol (ZOE) and an intraoral scanner (TRI) with a conventionally border molded ZOE impression (Control).
Methods: Edentulous maxillary impressions of twelve patients were taken with the above-mentioned impression techniques. The analog impressions were scanned using a laboratory scanner. The scans were imported in a 3D comparison software and superimposed against the corresponding control. Trueness was evaluated by root mean squares (RMS) of the entire surface, and specific regions of interest including the peripheral border (PB) and inner seal (IS). Paired t-test were applied to compare the mean RMS for each group (α=0.05).
Results: The total impression surface superimposition revealed mean RMS of 1.21±0.348mm, 0.75±0.17mm, 0.75±0.19mm, and 0.70±0.18mm for ALG, PVS, PVSM, and TRI, respectively. There were significant differences when comparing ALG versus PVS (p=0.0016), PVSM (p=0.0012), and TRI (p=0.0006). The mean RMS at PB were 2.03±0.55mm, 1.12±0.32mm, 1.05±0.29mm, and 1.38±0.25mm for ALG, PVS, PVSM and TRI, respectively. There were significant differences for PB when comparing ALG versus PVS (p=0.0006), PVSM (p=0.0002), and TRI (p=0.0014). There were significant differences for PB when comparing TRI to PVS (p=0.0420) and to PVSM (p=0.0160). The mean RMS at IS were 0.74± 0.36mm, 0.55±0.144mm, 0.51±0.12mm, and 0.8±0.25mm for ALG, PVS, PVSM and TRI, respectively. There were significant differences for IS when comparing ALG versus PVS (p= 0.0383) and PVSM (p=0.0225), but no significant difference to TRI.
Conclusions: Edentulous impressions taken with the PVS, PVSM and the intraoral scanner had similar deviations and may yield clinically acceptable results. The relevance of these deviations needs to be interpreted in a clinical context in view of denture retention, pain and adjustment sessions. Alginate should be discouraged for final impression taking in completely edentulous patients.
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: None