International Journal of Computerized Dentistry, 02/2016

This study evaluated the fracture loads of different threeunit fixed dental prostheses (FDPs) for temporary restorations. In total, three CAD/CAM materials (VITA CADTemp [CT], Telio CAD [TC], and ZENO ProFix [ZP]) and two chairside materials (Protemp 4 [PT], and Dentalon Plus [DP]) were used for the fabrication of the FDPs. Sixteen FDPs were fabricated from each material in an anatomical shape and stored in 0.9% NaCl solution at 37°C for 14 days. Thereafter, one half of the specimens from each group (n = 8) were additionally mechanically and thermally loaded (240,000 chewing cycles, 50 N, 5°/55°C, 2,100 thermal cycles). Fracture loads were measured and data analyzed using two- and one-way ANOVA, followed by Scheffé's post hoc test. ZP showed the highest mean fracture loads, regardless of the aging regime. Significantly lowest values were identified for DP and TC within the non-thermal loaded group, and for PT and CT within the thermal loaded group. No negative impact of aging regimes could be observed. Keywords: chewing simulation, fracture load, PMMA, polymeric CAD/CAM materials, temporary restorations

Nowadays, dental numerical controlled (NC) milling machines are available for dental laboratories (labside solution) and dental production centers. This article provides a mechanical engineering approach to NC milling machines to help dental technicians understand the involvement of technology in digital dentistry practice. The technical and economic criteria are described for four labside and two production center dental NC milling machines available on the market. The technical criteria are focused on the capacities of the embedded technologies of milling machines to mill prosthetic materials and various restoration shapes. The economic criteria are focused on investment cost and interoperability with third-party software. The clinical relevance of the technology is discussed through the accuracy and integrity of the restoration. It can be asserted that dental production center milling machines offer a wider range of materials and types of restoration shapes than labside solutions, while labside solutions offer a wider range than chairside solutions. The accuracy and integrity of restorations may be improved as a function of the embedded technologies provided. However, the more complex the technical solutions available, the more skilled the user must be. Investment cost and interoperability with third-party software increase according to the quality of the embedded technologies implemented. Each private dental practice may decide which fabrication option to use depending on the scope of the practice. Keywords: dental milling, CAD/CAM, surface integrity, Cerec, DMG MORI, Kavo, CharlyDental, Roland

Objectives: To evaluate the effect of immediate dentin sealing and optical powder removal method on the fracture resistance of CAD/CAM-fabricated ceramic endocrowns. Materials and methods: Seventy-eight extracted premolars were endodontically treated. Standardized endocrown preparations were done in 60 teeth. Teeth were divided equally (n = 10) depending on the treatment of dentin (delayed sealing [DS] or immediate sealing [IS]), and the methods of optical powder removal (air-water spray washing [AW]; microabrasion [MA]; or aqueous suspension of pumice [PB], followed by air-water spray washing). After cementation, specimens were thermocycled (5,000 cycles, 5°C/50°C) and stored in distilled water for 1 week. Specimens were loaded in compression using a universal testing machine until failure. Failure load was recorded, and modes of failure were examined under a stereomicroscope. Micromorphological evaluation of different dentin treatments was done under SEM (n = 3). Results were analyzed using two-way ANOVA and Bonferroni post hoc multiple comparison tests (α = 0.05). Results: Fracture resistance of all IS groups was significantly lower than DS groups, except for AW. There was no statistically significant difference between powder removal methods. Conclusion: Immediate dentin sealing does not improve the fracture resistance of endocrown restorations. Air-water spray washing is adequate to remove the optical powder after optical scanning impression taking. Keywords: adhesion, endocrown, immediate sealing, fracture resistance

"Digitality" (as opposed to "digitalization" - the conversion from the analog domain to the digital domain) will open up a whole new world that does not originate from the analog world. Contemporary research in the field of neural concepts and neuromorphic computing systems will lead to convergences between the world of digitality and the world of neuronality, giving the theme "Knowledge and Culture" a new meaning. The simulation of virtual multidimensional and contextual spaces will transform the transfer of knowledge from a uni- and bidirectional process into an interactive experience. We will learn to learn in a ubiquitous computing environment and will abandon conventional curriculum organization principles. The adaptation of individualized ontologies will result in the emergence of a new world of knowledge in which knowledge evolves from a cultural heritage into a commodity. Keywords: digitization, digitality, knowledge system, knowledge culture, ubiquitous computing, simulation, virtual patient, digital disease development simulation, digital treatment simulation, wisdom of community, ontological knowledge space, deep learning

The importance of monolithic ceramic restorations is growing, given the safe and cost-effective options for fabrication of such dental crowns and fixed dental prostheses. The optical characteristics of traditional zirconia do not suffice for this purpose. Improved restorative materials that can achieve satisfactory results in posterior restorations have been proposed to solve the problem. In the anterior region, however, even "esthetic" zirconia ceramic is unable to attain results comparable to those of glass-ceramic. Microveneering is a simple, reliable, and timesaving solution. Minimal reduction and veneering can significantly improve the results. A characteristic case is presented here. Keywords: all-ceramic, CAD/CAM, esthetics, fixed dental prostheses, zirconia