Publications by authors named "Andreas Dominik Schwitalla"

Objective: Achieving a strong bond between Polyetheretherketone (PEEK) and veneering composites is challenging due to PEEKs low surface energy. This study examined the effects of sandblasting and bonding on the shear bond strength (SBS) between veneering composite and pigmented PEEK, considering artificial aging.

Methods: Of three pigmented PEEK compounds (DC4420R, DC4450R, DC4470R; Evonic Operations GmbH, Marl, Germany), 40 specimens each were milled and polished up to 2500 grit.

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Material extrusion of thermoplastic polymers enables the realization of complex specific designs with high performance composites. The present study aims at evaluating the mechanical properties of carbon fiber-reinforced semi-crystalline thermoplastic polymer polyether ether ketone (CFR-PEEK) manufactured by material extrusion and correlating them with results obtained by micro-CT. Samples in the shape of small bars were provided by Kumovis (Munich, Germany).

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Objective: Due to its favorable properties, the high-performance polymer polyetheretherketone (PEEK) is used as a metal-free alternative for the fabrication of denture frameworks. For dental applications, PEEK is available in different colors, such as red or white, by compounding with different fillers. In order to permanently bond such different dental PEEK types together in a denture framework, ultrasonic welding could be a viable process.

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Objective: Telescopic crowns are suitable components of partial dentures to efficiently anchor dental supra-structures to teeth or dental implants and achieve high chewing performance and wear comfort. Usually alloy- or metal-based structures are used for the primary and the secondary crowns. The advantage is the possibility to produce precise structures with a high perfection and sufficient friction force, but the disadvantage is the corrosion instability.

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of experiments was employed to investigate the combinations of 3D-printing parameters for Polyether ether ketone (PEEK) with a fused filament fabrication (FFF) process and to quantitatively evaluate the quality of 3D printed parts. This research was conducted using a newly developed FFF 3D printer and PEEK filament. Standard PEEK parts were 3D printed for bending and compression tests.

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Objective: Plasma treatment can be used as surface treatment of PEEK (poly-ether-ether-ketone) to increase the bonding strength between veneering composite and dental prosthetic frameworks of PEEK or enhance biocompatibility of PEEK implants. These improvements are probably based on chemical changes of the PEEK surface. However, the aim of the study was to evaluate the impact of different low-pressure plasma treatments on surface properties of PEEK, such as roughness, hydrophilicity, micro-hardness, crystallinity and biological activity of PEEK.

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Due to its elastic modulus close to bone, the high-performance material PEEK (polyetheretherketone) represents an interesting material for implant-supported dental prostheses. Besides a damping effect of masticatory forces, it might have a sealing effect against bacterial leakage of the implant-abutment interface (IAI). So far, PEEK has only been used for provisional implant crowns.

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Objective: The aim of this study was to assess the degradation behavior by measuring the H release of a biodegradable composite consisting of a polylactic acid matrix reinforced with 30% wt. spherical magnesium microparticles (PLA/Mg) as potential bone augmentation material in combination with dental implants of either titanium or polyetheretherketone (PEEK) in order to evaluate the potential influence of the titanium dental implants on the corrosion behavior of the Mg particles within the PLA matrix.

Methods: Three PEEK dental implants and three titanium dental implants were put into a central perforation of six PLA/Mg-discs.

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Objective: The aim of this study was to evaluate the impact of oxygen and argon/oxygen low-pressure plasma on the shear bond strength (SBS) between dental PEEK compounds and veneering composites as a function of plasma process time.

Methods: Of an unfilled PEEK ("Juvora") and two pigment powder filled PEEK compounds ("DC4420", "DC4450"), 273 rectangular plates were prepared and polished up to 1200 grit. Afterwards the samples were sandblasted and randomly assigned to five different surface pre-treatment groups (1.

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Frequent reports attest to the various advantages of tapered implant/abutment interfaces (IAIs) compared to other types of interfaces. For this reason, a conical IAI was designed as part of the development of a PEEK (polyetheretherketone)-based dental implant. This IAI is equipped with an apically displaced anti-rotation lock with minimal space requirements in the form of an internal spline.

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Objective: The aim of the study was to evaluate the impact of low-pressure argon/oxygen plasma with and without previous sandblasting on the shear bond strength (SBS) between dental PEEK compounds and a veneering composite.

Methods: Of one type of unfilled PEEK and two pigment powder filled PEEK compounds, forty rectangular plates each were prepared and polished up to 4000 grit. The samples were randomly assigned to four surface pre-treatment groups, each consisting of ten specimens (1.

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The increasing use of PEEK (poly-ether-ether-ketone) as a substitute for metal implant components has led to the suggestion that it could also be used as an alternative to titanium in the field of dental implants. A major requirement for dental implant materials is their resistance to cyclic loading due to mastication. A special fatigue test was designed to evaluate the elastic behavior and long-term form stability of cylindrically shaped PEEK specimens of 4, 5 and 6mm in diameter, using 11 different PEEK materials of various grades: unfilled, filled with titanium dioxide or barium sulfate powder, reinforced with short carbon fibers or short glass fibers, and reinforced with continuous carbon fibers.

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The high-performance polymer PEEK (poly-ether-ether-ketone) is more and more being used in the field of dentistry, mainly for removable and fixed prostheses. In cases of screw-retained implant-supported reconstructions of PEEK, an abutment screw made of PEEK might be advantageous over a conventional metal screw due to its similar elasticity. Also in case of abutment screw fracture, a screw of PEEK could be removed more easily.

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Bacterial leakage from the implant-abutment-interface (IAI) is suspected of contributing to the development of peri-implantitis. The aim of the study was to develop a straightforward test setup to evaluate the bacterial leakage of the IAI of 2-piece implant systems under laboratory conditions. A test suspension of Enterococcus faecium was injected into 7 implants (PerioType Rapid Implants) prior to abutment fixation.

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Due to its mechanical properties, the biocompatible high-performance material PEEK (polyetheretherketone) and PEEK-based compounds may represent viable alternatives to titanium in the field of dental implantology. Therefore we performed static pressure tests with 11 PEEK materials (two unfilled grades, two grades filled with titanium-dioxide-powder, two grades filled with barium-sulfate-powder, two grades reinforced with short carbon fibers, one grade reinforced with glass fibers and two grades reinforced with continuous carbon fibers) in the form of cylindrical specimens with a diameter of 4, 5 and 6mm. The specimens had a height to diameter ratio of 2:1 and were therefore 8, 10 and 12mm high.

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Objectives: The high-performance thermoplastic polymer PEEK (poly-ether-ether-ketone) is used as alternative implant material to metals since 1998 in many medical fields due to its bone-like mechanical properties. These iso-elastic characteristics of PEEK lead to the assumption, that it could represent a viable alternative to conventional materials also in the field of dentistry. Therefore the mechanical properties of different PEEK-compounds should be eavuated vie the three-point bending test.

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