Fabrication of complete dentures (CDs) utilizing computer-aided design and computer-aided manufacturing (CAD/CAM) methods has attracted a lot of attention. The purpose of this paper was to summarize current knowledge about digital CDs and the relevant technology, and to present the application of the new technology in a dental geriatrics case. Initially, some of the challenges regarding digitization of the oral mucosa as a supporting surface of the CDs’ intaglio surface are listed. Next, a brief introduction of the CAD software capabilities regarding CDs is presented. The latest CAM additive and subtractive techniques for CDs are following. Subsequently, the consecutive steps for the construction of a digital CD as part of the prosthodontic treatment of a 90-year-old ambulative female patient are presented. Finally, some considerations about the digital workflow in CD manufacturing are discussed. In conclusion, the new digital technology has clear advantages; however, implementation requires careful planning. The digital workflow is applicable and versatile.

One of the key arguments in favor of digitally produced complete dentures (CDs) is the requirement for less patient visits in comparison to the conventional workflow. However, it is not yet clear if this argument is accurate; nor, if indeed the insertion of the complete dentures is achieved in fewer appointments, how many are required. The purpose of this literature review was to investigate the reported number of required patient visits for the production of digitally fabricated CDs. An electronic search was performed in PubMed/MEDLINE using three groups of keywords: “complete dentures”, “CAD/CAM”, and “Appointments” with their alternative forms. Out of the initial 157 results, 36 articles were automatically selected utilizing exclusion keywords. After consensus between the two examiners, eight articles were finally analyzed and presented in a table. The majority (75%) of the reports came from institutions, and the average number of appointments up to complete denture insertion was 4.1, not always including try-in dentures. In this study, it can be concluded that, with a digital workflow, the insertion appointment is reached in fewer visits than the conventional five-visit procedure which is commonly taught in dental schools.

Newly developed 3D-printed polymer materials are used for denture base fabrication. The aim of the present study was to evaluate the color stability of two new 3D-printed resins, a hard PPMA-based and a soft Urethane-based resin, in relation to a traditional heat-polymerized PMMA resin, which was used for comparison purposes. Specimens of the materials were immersed in five solutions (distilled water, red wine, black tea, coffee, and Coke^®) for definite periods of time (one day, one week, and one month). The color measurements were carried out utilizing a spectrometer supported by a microscope and using special software. Color changes between immersion periods were calculated and statistically compared. The results showed that all types of resins were influenced during immersion periods. The heat-polymerized resin was influenced less than the others but with no significant difference to the 3D-printed hard PMMA resin. In respect to the materials compared, the discoloration effect for the 1 month immersion time was significantly more intense for the soft 3D-printed resin. In respect to the solutions’ staining effects, black tea and red wine significantly discolored all materials regardless of immersion periods. The new 3D-printed materials need further improvements for dental use.

This study examines how porcelain firing cycles and fabrication methods impact the microstructure and the marginal and internal fit of implant‐cemented Co–Cr frameworks. Two fabrication processes for Co–Cr specimens were used: hard milling or soft milling. Each type of framework was then allocated to use either as‐fabricated or as porcelain‐fired. The microstructural analysis employed x‐ray diffraction (XRD) and scanning electron microscopy with energy‐dispersive x‐ray spectroscopy (SEM/EDX). A total of ten Co–Cr frameworks were fabricated for each method, and discrepancies in margin and internal fit were evaluated using X‐ray microtomography (micro‐CT) before and after the porcelain firing. Statistical analysis was performed using two‐way ANOVA and Tukey's multiple comparison tests (α = 0.05). The findings indicated a combination of γ‐fcc and ε‐hcp cobalt‐based phases, with porcelain firing notably enhancing the ε‐Co content, particularly among soft milled specimens. Soft milled specimens exhibited a diffuse presence of pores, while hard milled specimens revealed a random distribution of small pores. The soft milled specimens exhibited a significant reduction in discrepancies after the application of firing cycles. Although not statistically significant, the hard milled specimens also showed a trend toward reduced discrepancies post‐firing. All subgroups maintained clinically acceptable marginal adaptation, with soft milled frameworks outperforming their hard milled counterparts in overall fit.

This study investigated the effect of porcelain firing cycles and fabrication techniques on the microstructure, marginal, and internal fit of implant‐cemented cobalt‐chromium alloys (Co‐Cr) frameworks. Two groups of Co‐Cr specimens were prepared: one using selective laser melting (SLM) and the other through the lost wax‐casting technique (C). Each group was further divided into two subgroups: as‐manufactured and porcelain‐fired specimens. The microstructure was analyzed using x‐ray diffraction (XRD) and scanning electron microscopy with energy‐dispersive x‐ray spectroscopy (SEM/EDX). Ten Co‐Cr frameworks per manufacturing technique were fabricated, with marginal and internal discrepancies measured using micro‐CT before and after the firing cycles. The results were analyzed by two‐way ANOVA and Tukey multiple‐comparison tests. The results showed a mixed microstructure of γ‐fcc and ε‐hcp cobalt‐based phases, with porcelain firings increasing ε‐Co content, especially in group C. The C specimens exhibited distribution of small pores, while no pores/defects were found in the SLM group. The SLM group, although not at a statistically significant level, showed reduced marginal and internal discrepancy values after firings. In the same behavior pattern, the C group exhibited statistically significantly lower discrepancy values. Ultimately, all subgroups demonstrated clinically acceptable marginal adaptation, but the SLM frameworks exhibited superior marginal and internal fit which remained unaffected by the firing cycles.

Objectives: This in vitro study aimed to evaluate the effects of three framework orientation (FO) positions on an SLM building platform (Horizontal [H], Diagonal-45° [D45°], Diagonal-60° [D60°]) and two designs (with [B] or without [NB] stabilizing bars) on the fitting accuracy of digitally fabricated Co-Cr RPD frameworks. Materials and Methods: A custom RPD framework CAD was performed on a 3D-printed resin-model of an edentulous maxilla with three geometric tooth forms. A Co-Cr alloy was processed via SLM processing into 24 framework specimens, divided into three FO groups (n = 8: H, D45°, D60°) and two subgroups each (n = 4: B, NB). Qualitative/quantitative fit-evaluation was assessed using virtual framework-to-model seating and a custom digital protocol with GOM Inspect software (2018-Hotfix5, Rev.115656). Mean fitting distances were calculated from 220 equidistant points per specimen. Statistical comparisons were performed using ANOVA-on-ranks, Kruskal–Wallis multiple comparisons, and Bonferroni adjustment. Results: FO Sub-Group medians (Q1, Q3: 25% and 75% Quartiles) (mm) were: H/NB 0.150 (0.140, 0.164), H/B: 0.136 (0.121, 0.152), D45°/NB: 0.230 (0.219, 0.241), D45°/B: 0.144 (0.137, 0.154), D60°/NB:0.238 (0.232, 0.247), D60°/B: 0.171 (0.166,0.176). Pairwise comparisons indicated the following statistically significant (p < 0.05) FO Sub-Group differences: H/B-D45°/NB, H/B-D60°/NB, D45°/B-D45°/NB, D45°/B-D60°/NB, H/NB-D45°/NB, H/NB- D60°/NB. Conclusions: Horizontal orientation improved RPD fit accuracy regardless of bar presence. D45° accuracy is enhanced by stabilizing bars, while D60° accuracy is unaffected by bar addition.