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Content available Comparison of 3D printing MJP and FDM technology in dentistry
Taczała J., Czepułkowska W., Konieczny B., Sokołowski J., Kozakiewicz M., Szymor P.
Archives of Materials Science and Engineering
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2020
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Vol. 101, nr 1
32--40
EN
Purpose: Many printers are tempting at low prices, but later their accuracy turns out to be insufficient. The study has included checking the accuracy of printing and reproducing details of 3D printers used in dental technology and dentistry such as MultiJet Printing (ProJet MP3000, 3D Systems) and Fused Deposition Modelling (Inspire S2000, Tiertime). Design/methodology/approach: The 3D prints were created from scans of the maxillary gypsum model with the loss of left premolar. In the test, objects were set to the X and Y-axis. In order to check the dimensional differences after printing, scans of the printed models were superimposed on scans of the plaster model in the GOM Inspect V8 SR1 (Braunschweig, Germany). The focus was on the distance of scans from each other and a deviation map was created for each object. Findings: The average absolute value of deviations for each of models were equalled: FDM- for X-axis 0.06 ± 0.04 mm, for Y-axis 0.07 ± 0.04 mm; MJP- for X-axis- 0.04 ± 0.02 mm, for Y-axis- 0.06 ± 0.02 mm. A chart of arithmetic averages calculated for each tooth for the best printouts in each series show that higher deviation values exist in case of FDM printout. The models printed in the X-axis have smaller values of deviations from those printed in the Y-axis. Practical implications: MultiJet Printing technology can be used to create more precise models than the FDM, but these printouts meet the requirements of dimensional accuracy too. Originality/value: CAD / CAM technology in the future will exist in every dental technology laboratory so it is important to be aware of the way the 3D printers works. By paying attention to the quality of detail reproduction, a Dental Technician is able to choose the best 3D printer for them.
2
Content available remote The role of mechanical, chemical and physical bonds in metal-ceramic bond strength
Czepułkowska W., Wołowiec-Korecka E., Klimek L.
Archives of Materials Science and Engineering
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2018
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Vol. 92, nr 1
5--14
EN
Purpose: A review regarding the mechanisms of metal-ceramic join is presented. Design/methodology/approach: The impact of the air-abrasion parameters on the mechanical bond strength of the ceramic crowns was discussed. The presence of opaque on the chemical bond was analysed. Research of the influence of the difference in the coefficient of thermal expansion values on the metal-ceramic bond was included. The methods of testing the bond strength were analysed. Findings: The metal substructure-dental ceramic bond strength is affected by all types of bond. In bond strength, 3-point bending test and shear test are mainly used. Created samples simulate the ceramic crowns veneered on one side. The role of physical bond on ceramic crowns veneered around metal substructure is unknown. Research limitations/implications: The prosthetic restorations with the ceramic surrounding whole the metal substructure are commonly used. The impact of shrinkage in the cylindrical deposition of the ceramic on metal substructure should be analysed. Practical implications: Numerical analysis and FEM simulation can be helpful in the analysis of the physical bond between the metal substructure and the dental ceramic around it. Originality/value: The impact of the type of the bond to metal-ceramic bond strength is presented, taking into account the cognitive gap in the influence of the coefficient of thermal expansion on the cylindrical placement of ceramic on the substructure.
3
Content available remote Fretting in orthodontics and its test methods
Czepułkowska W., Jastrzębski W.
Archives of Materials Science and Engineering
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2018
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Vol. 94, nr 2
55--64
EN
Purpose: A review of the literature regarding the occurrence of fretting wear in orthodontics and its test methods have been presented. Design/methodology/approach: The influence of micro-movements occurring in the oral cavity on the occurrence of fretting wear in a fixed orthodontic appliance is discussed. The fretting test methods were analysed, taking into account tine shape of the samples and the amplitude of the movements, calculated according to the Hertz contact problem. Fretting-corrosion tests on tines wear of materials are included. Findings: Fretting occurs between the bracket and the orthodontic archwire in a fixed appliance. The test of the amount of wear material mainly uses samples created for the needs of the device. The test of ready-made components of a fixed appliance usually relate to the value of the coefficient of friction. The use of coatings increases the coefficient with the simultaneous reduction of the amount of wear material. Fretting-corrosion occurring in the oral environment has a negative impact on the wear of materials. The value of the total area of abraded material after fretting is unknown. Research limitations/implications: Particles of fretting wear
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