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Notchless trianguler prism fracture toughness of new indirect composite
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d e n t a l m a t e r i a l s 3 2 S ( 2 0 1 6 ) e1–e103
68 Notchless trianguler prism fracture toughness of new indirect composite H. Kato ∗ , D. Machida, T. Ueno, T. Kumagai GC Corporation, R&D Center, Tokyo, Japan Purpose/Aim: We developed new indirect composite system, GRADIA PLUS LB (Light Body)/HB (Heavy body). GRADIA PLUS overcomes weaknesses of Micro-Filled Resin (MFR) by adopting nano-filler technology same as G-aenial universal flo (GC) and CERASMART (GC), demonstrating high wear resistance and high mechanical properties. Fracture toughness of dental materials is evaluated as a method to measure a resistance level of the destruction. Recently, notchless trianguler prism (NTP) fracture toughness test has been paid attention as an effective method for measuring fracture toughness of composite resin. The purpose of this study is to evaluate the NTP fracture toughness of GRADIA PLUS and other indirect composites. Materials and methods: GRADIA PLUS LB/HB, GRADIA (GC), Signum ceramis (Heraeus Kulzer), crea.lign flow (Bredent), crea.lign paste (Bredent) and SR nexco paste (Ivoclar/Vivadent) as indirect composites were examined in this study. NTP specimens of each indirect composite were formed for each material using metal mold and cured according to the manufacturers’ instructions for use. All specimens were stored in 37 ◦ C water for 24 hours. NTP fracture toughness test was performed with multi testing machine (Autograph, SHIMADZU), and a fracture morphology of each prism was inspected by scanning electron microscope (SEM, HITACHI). KIC was calculated by following equation, KIC = Pmax × Y*min/(DW0.5) where Pmax = the maximum load at fracture (N), D = the specimen diameter (12 mm), W = the specimen length (10.5 mm), and Y*min = the minimum of the dimensionless stress intensity factor coefficient (= 28). Results were analyzed by one-way ANOVA (p < 0.05). Results: Evaluation of NTP fracture toughness needs that the fracture morphology is indicative of plane strain conditions, so fracture surface was observed by SEM. GRADIA PLUS LB and HB exhibited significantly higher NTP fracture toughness compared to the other indirect composite (shown
Fig. 1
in Fig. 1). Fracture toughness was influenced with many factors which are by size, form and content rate of glass filler and strength of resin matrix in composite resin. Results of this study suggested that GRADIA PLUS shows higher fracture toughness due to nano-filler technology. Conclusions: New indirect composite, GRADIA PLUS LB and HB, showed higher NTP fracture toughness than the other indirect composite, and it may suggest that GRADIA PLUS is not easily fractured for clinical use. http://dx.doi.org/10.1016/j.dental.2016.08.069 69 New calcium sulphate powder-binder system for 3D printing J. Barrera ∗ , C.A. Morales, C. Álvarez Universidad Nacional Autónoma De México, Mexico Purpose/Aim: Develop a new powder-binder system for 3D printing used in maxillofacial prosthesis. Materials and methods: The SEM and EDS study of zp® 151 3DSYSTEMS® was performed with the scanning electron microscopy low vacuum. The infrared spectroscopy study of zp® 151 powder and liquid ZB TM 61 Clear Binder Solution 3DSYSTEMS® were performed on a spectrometer Fourier transform. For the thermogravimetric analysis the sample was placed in the thermobalance in air atmosphere and heated at a rate of 10 ◦ C per minute. Subsequently the bands databases that marks the literature were compared. For the synthesis of the binder solution, polyacrylic acid (PAA) at 1.5%, 1%, 0.75%, 0.5% and 0.25% and deionized water were mixed using a magnetic stirrer until the polymer completely dissolved. For the powder, Dental® mdc, NICSTONE, and Zhermack®, dental stones elite®, were tested. Subsequently, samples in stainless steel molds, 4 mm diameter by 6 mm height were made and it allowed dry the samples at room temperature, 24 exact times were subjected to a load of 50 ± 16 N/min, the resistance and modulus of elasticity values were obtained as averages. Results: The composition of the sample according EDS were: 48.10% O, 27.32% Ca, 8.14% S, 9.02% Si, 1.16% Na, and 0.32% Mg. Also the shape of the powder particles was: mostly irregular prisms of 50–80 m. In the IR analysis of the powder, concordant bands with molecules of calcium sulphate as the link S-O between 1100 and 1400 were detected. In the IR liquid the three water bands characteristics (3225, 1625, 994) were found, and a small band 2124 corresponding to a triple bond who corresponds to an acetylene-based acrylic polymer. As a result of the mechanical tests an average value of compressive strength of the original material of 15.4 MPa and an elastic modulus of 1997 MPa was achieved, taking into account the different formulations were tested, which came closest to the original powder and binder was dental gypsum elite® with PAA to 0.25%. Conclusions: With this study the components and characteristics of the material used in stereolithography were identified, the powder is a calcium sulphate and the binder comprises a polymer dissolved in water. With the previously mentioned data, was developed a new formula for the benefit
d e n t a l m a t e r i a l s 3 2 S ( 2 0 1 6 ) e1–e103
68 Notchless trianguler prism fracture toughness of new indirect composite H. Kato ∗ , D. Machida, T. Ueno, T. Kumagai GC Corporation, R&D Center, Tokyo, Japan Purpose/Aim: We developed new indirect composite system, GRADIA PLUS LB (Light Body)/HB (Heavy body). GRADIA PLUS overcomes weaknesses of Micro-Filled Resin (MFR) by adopting nano-filler technology same as G-aenial universal flo (GC) and CERASMART (GC), demonstrating high wear resistance and high mechanical properties. Fracture toughness of dental materials is evaluated as a method to measure a resistance level of the destruction. Recently, notchless trianguler prism (NTP) fracture toughness test has been paid attention as an effective method for measuring fracture toughness of composite resin. The purpose of this study is to evaluate the NTP fracture toughness of GRADIA PLUS and other indirect composites. Materials and methods: GRADIA PLUS LB/HB, GRADIA (GC), Signum ceramis (Heraeus Kulzer), crea.lign flow (Bredent), crea.lign paste (Bredent) and SR nexco paste (Ivoclar/Vivadent) as indirect composites were examined in this study. NTP specimens of each indirect composite were formed for each material using metal mold and cured according to the manufacturers’ instructions for use. All specimens were stored in 37 ◦ C water for 24 hours. NTP fracture toughness test was performed with multi testing machine (Autograph, SHIMADZU), and a fracture morphology of each prism was inspected by scanning electron microscope (SEM, HITACHI). KIC was calculated by following equation, KIC = Pmax × Y*min/(DW0.5) where Pmax = the maximum load at fracture (N), D = the specimen diameter (12 mm), W = the specimen length (10.5 mm), and Y*min = the minimum of the dimensionless stress intensity factor coefficient (= 28). Results were analyzed by one-way ANOVA (p < 0.05). Results: Evaluation of NTP fracture toughness needs that the fracture morphology is indicative of plane strain conditions, so fracture surface was observed by SEM. GRADIA PLUS LB and HB exhibited significantly higher NTP fracture toughness compared to the other indirect composite (shown
Fig. 1
in Fig. 1). Fracture toughness was influenced with many factors which are by size, form and content rate of glass filler and strength of resin matrix in composite resin. Results of this study suggested that GRADIA PLUS shows higher fracture toughness due to nano-filler technology. Conclusions: New indirect composite, GRADIA PLUS LB and HB, showed higher NTP fracture toughness than the other indirect composite, and it may suggest that GRADIA PLUS is not easily fractured for clinical use. http://dx.doi.org/10.1016/j.dental.2016.08.069 69 New calcium sulphate powder-binder system for 3D printing J. Barrera ∗ , C.A. Morales, C. Álvarez Universidad Nacional Autónoma De México, Mexico Purpose/Aim: Develop a new powder-binder system for 3D printing used in maxillofacial prosthesis. Materials and methods: The SEM and EDS study of zp® 151 3DSYSTEMS® was performed with the scanning electron microscopy low vacuum. The infrared spectroscopy study of zp® 151 powder and liquid ZB TM 61 Clear Binder Solution 3DSYSTEMS® were performed on a spectrometer Fourier transform. For the thermogravimetric analysis the sample was placed in the thermobalance in air atmosphere and heated at a rate of 10 ◦ C per minute. Subsequently the bands databases that marks the literature were compared. For the synthesis of the binder solution, polyacrylic acid (PAA) at 1.5%, 1%, 0.75%, 0.5% and 0.25% and deionized water were mixed using a magnetic stirrer until the polymer completely dissolved. For the powder, Dental® mdc, NICSTONE, and Zhermack®, dental stones elite®, were tested. Subsequently, samples in stainless steel molds, 4 mm diameter by 6 mm height were made and it allowed dry the samples at room temperature, 24 exact times were subjected to a load of 50 ± 16 N/min, the resistance and modulus of elasticity values were obtained as averages. Results: The composition of the sample according EDS were: 48.10% O, 27.32% Ca, 8.14% S, 9.02% Si, 1.16% Na, and 0.32% Mg. Also the shape of the powder particles was: mostly irregular prisms of 50–80 m. In the IR analysis of the powder, concordant bands with molecules of calcium sulphate as the link S-O between 1100 and 1400 were detected. In the IR liquid the three water bands characteristics (3225, 1625, 994) were found, and a small band 2124 corresponding to a triple bond who corresponds to an acetylene-based acrylic polymer. As a result of the mechanical tests an average value of compressive strength of the original material of 15.4 MPa and an elastic modulus of 1997 MPa was achieved, taking into account the different formulations were tested, which came closest to the original powder and binder was dental gypsum elite® with PAA to 0.25%. Conclusions: With this study the components and characteristics of the material used in stereolithography were identified, the powder is a calcium sulphate and the binder comprises a polymer dissolved in water. With the previously mentioned data, was developed a new formula for the benefit