3D Printed Temporary Veneer Restoring Autotransplanted Teeth in Children: Design and Concept Validation Ex Vivo

Abstract

(1) Background: Three-dimensional printing is progressing rapidly and is applied in many fields of dentistry. Tooth autotransplantation offers a viable biological approach to tooth replacement in children and adolescents. Restoring or reshaping the transplanted tooth to the anterior maxilla should be done as soon as possible for psychological and aesthetic reasons. However, to avoid interfering with the natural healing process, reshaping of transplanted teeth is usually delayed three to four months after transplantation. This delay creates a need for simple indirect temporary aesthetic restoration for autotransplanted teeth. The aim of this study was to develop and validate a digital solution for temporary restoration of autotransplanted teeth using 3D printing. (2) Methods: Four dry human skulls and four dry human mandibles were scanned using cone beam computed tomography to create 3D models for 15 premolars. Digital impression of the maxillary arch of one of the skulls was captured by intra oral scanner. The digital work flow for the design and fabrication of temporary veneers is presented. The seating and adaptation of the 3D printed veneers were evaluated using stereomicroscopy and micro-computed tomography. (3) Results: Evaluation of the veneer seating using stereomicroscopy showed that the mean marginal gap at all of the sides was below the cut-off value of 200 µm. The overall mean marginal gap was 99.9 ± 50.7 µm (median: 87.8 (IQR 64.2⁻133 µm)). The internal adaptation evaluation using micro-computed tomography showed an average median gap thickness of 152.5 ± 47.7 (IQR 129⁻149.3 µm). (4) Conclusions: The present concept of using temporary veneers that are designed and fabricated with CAD/CAM (computer-aided design/computer-aided manufacturing) technology using a DLP (digital light processing) printer may present a viable treatment option for restoration of autotransplanted teeth.

Keywords: 3D printing; CAD/CAM; CBCT; DLP; tooth autotransplantation.

Figure 1

Digital flow for temporary veneer preparation. (A) Premolar segmentation; (B) designing temporary veneer based on the shape of the contralateral incisor (to mimic the clinical situation where one maxillary central incisor will be lost, a mirror image of the contralateral maxillary incisor was used to design the temporary veneer that will fit the transplanted premolar); (C) checking veneer thickness to ensure optimal printing; (D) final veneer design: removing undercuts, beveling the edges (green arrow), and inspecting the surface thickness is done to avoid print failure spots.

Figure 2

3D printed veneer and evaluation methods. (A) 3D printed veneer and fitting to premolar; (B) evaluation of veneer seating using stereomicroscopy; (C) internal gap evaluation using micro-computed tomography, D: quantitative analysis of gap thickness.

Figure 3

(A) stereomicroscopy gap measurements; (B) distribution of the gap thickness between the veneer and the tooth.