In vivo study of intraoral scanner trueness in partial edentulism

Abstract

The purpose of this study was to evaluate the trueness of complete-arch intraoral scanning of maxillary partially edentulous patients. Sixty-four patients with partially edentulous upper jaws were recruited. The intraoral digital impressions were obtained by Trios 3 scanner. Conventional impression procedure was performed with polyether silicone rubber as reference models. The trueness of intraoral digital impressions for dentition, edentulous area, and palate was calculated by aligning digital scanning data to conventional impression data using Geomagic Studio 2013. Data were classified according to arch width, palatal vault height, Kennedy classification, as well as number and distribution of missing teeth. There were significant differences among the average absolute deviations of dentition (61.9 ± 36.8 μm), palate (115.9 ± 44.3 μm), and edentulous area (63.0 ± 37.1 μm) (P < 0.001). There was no significant effect of arch width, Kennedy Classification, or number and distribution of missing teeth on the trueness of digital impressions (P > 0.05), while the intraoral scanning trueness of edentulous area tended to decrease in patients with higher palatal vault (P = 0.003). Thus, it is feasible to use intraoral scanner to obtain the digital impressions for the fabrication of RPDs. The trueness of patients with higher palatal vault needs more attention and verification.

Keywords: Best-fit alignment; Edentulous area; Intraoral scanning; Palate; Removable partial dentures; Trueness.

Fig. 1

Flow diagram of the study.

Fig. 2

Scanning sequence of intraoral scanner.

Fig.3

Trueness of intraoral digital impression of dentition, palate, edentulous area, and entire maxilla. The black dots represent outliers, and “ + ” denotes the mean value. ***P < 0.001.

Fig.4

Color-coded maps of whole maxilla.