Evaluation of the marginal and internal fit of provisional crown fabricated with two different 3D printing technologies

Abstract

CAD/CAM technology represents a well-established and always improving tool for the realization of dental prosthetics, appliances and clinical devices. The aim of this paper is to evaluate the marginal and internal fit of provisional crowns realized with two different technology modern 3D printers. 60 patients needing a single crown prosthetic restoration were enrolled for the study and for each case two resin 3D Printed temporary crowns were produced on the same CAD project file realized on an intraoral digital scan. All digital impressions were taken with Trios 3 Color Pod Scanner (3 Shape) and the two 3D Printers tested were: DLP-SLA (Moonray D75) and MSLA (Structo Velox).Assessment of marginal and internal fit was carried out by a single blind VAS quality assessment by the operator fitting the temporaries on the patients and by a qualitative analysis of the gap thickness in sections obtained from silicon imprints of the fitted temporary crown on the relative tooth measured in four different points.Both 3D printing technologies gave promising results with measured gaps always under 130 μm but failed the comparison with traditional techniques in terms of cost-effectiveness and time saving. In every case, adjustments and finishing was always needed for a correct fitting a clinical function of the temporary restoration. Nowadays, other 3D CAM procedures such as precured resin blocks milling, appear to be more indicated for the fabrication of temporary prosthetic crowns.