Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) Complete Dentures for Atrophic Alveolar Ridges: Workflow Combining Conventional and Novel Techniques

Intaglio surface trueness of dentures bases fabricated with 3D printing vs. conventional workflow: a clinical study

The latest generation of intraoral scanners can record the prosthetic field with relative ease, high accuracy and comfort for the patient, and have enabled fully digital protocols for designing and manufacturing complete dentures. The present study aims to examine the intaglio surface trueness of 3D printed maxillary dentures produced by fully digital workflow in comparison with dentures produced by analogue clinical and laboratory prosthetic workflow. The edentulous maxillary arch of 15 patients was scanned with an intraoral scanner as well as the intaglio of the delivered conventional denture. The scan of the edentulous arch was imported into a dental design software to produce the denture base which was then 3D printed. The intaglio surface of the finished 3D printed denture bases was digitized and used to assess the trueness of the printed denture bases compared to the intaglio surface of the conventional dentures as well as performing a trueness comparison in relation to the scanned edentulous arches. The dataset (n = 30) was subjected to Kruskal-Wallis test analysis, the significance level being established at α = 0.05. The results of the study showed that the printed group displayed better trueness values with a median of 176.9 μm while the analogue group showed a median of 342 μm. Employing a fully digital workflow to produce 3D-printed denture bases yields a consistent and precise manufacturing method when accounting for the intaglio surface of the denture.

Ceramic and Composite Polishing Systems for Milled Lithium Disilicate Restorative Materials: A 2D and 3D Comparative In Vitro Study

Purpose: This study aims to evaluate the effectiveness of two ceramic and two composite polishing systems for a novel chairside computer-aided design/computer-aided manufacturing (CAD/CAM) lithium disilicate ceramic with three-dimensional and two-dimensional microscopy images. This ceramic material can be used for implant-supported or tooth-borne single-unit prostheses. Materials and Methods: Sixty flat samples of novel chairside CAD/CAM reinforced lithium disilicate ceramic (Amber Mill, Hass Bio) were divided into five groups (n = 15/group) and treated as follows: Group 1 (NoP), no polished treatment; group 2 (CeDi), polished with ceramic Dialite LD (Brasseler USA); group 3, (CeOp) polished with ceramic OptraFine (Ivoclar Vivadent); group 4, (CoDi) polished with composite DiaComp (Brasseler USA), and group 5 (CoAs), polished with composite Astropol (Ivoclar Vivadent). The polished ceramic surface topography was observed and measured with three-dimensional and two-dimensional images. Results: All polishing systems significantly reduced the surface roughness compared with the non-polished control group (Sa 1.15 μm). Group 2 (CeDi) provided the smoothest surface arithmetical mean eight with 0.32 μm, followed by group 3 (CeOp) with 0.34 μm. Group 5 (CoAs) with 0.52 μm provided the smoothest surface among the composite polishing kits. Group 4 (CoDi) with 0.66 μm provided the least smooth surface among all polishing systems tested. Conclusions: Despite the effectiveness of ceramic polishing systems being superior to composite polishing systems of the CAD/CAM lithium disilicate restorative material, both polishing systems significantly improved the smoothness.