선택적 침투 부식법(Selective infiltration etching technique)이 지르코니아와 비니어 세라믹의 전단결합강도에 미치는 영향

박다령(Da-Ryeong Park),김정미(Jeong-Mi Kim),정수하(Su-Ha Jeoung),배지명(Ji-Myung Bae),오승한(Seunghan Oh) 대한치과재료학회 2014 대한치과재료학회지 Vol.41 No.2

The purpose of this research was to treat the surface of zirconia via glass infiltration etching technique and estimate the effect of this etching technique on the shear bond strength of zirconia and veneering ceramic. 3 mol% Y2O3 stabilized zirconia powder and glass powder used in preparing veneering ceramic were mixed with various amounts (20, 40, 60, 80, and 100 wt%). The shear bond strength and failure mode of veneering ceramic which was produced on the etched zirconia surface were analysed. From the results of bond strength test showed that the value of 80 wt% glass group (35.52 ± 5.24 MPa) was significantly higher than that of other experimental groups (p < 0.05). The observation of fractured surfaces of experimental specimens indicated that 80 and 100 wt% glass groups showed cohesive failure and other groups illustrated adhesive and mixed failure mostly. Therefore, glass infiltration etching technique was expected to enhance the bond strength of zirconia and veneering ceramic and be feasible in clinical usage.

글리세린이 coloring liquid의 침투와 지르코니아 경도에 미치는 영향

박다령(Da-Ryeong Park),배지명(Ji-Myung Bae),오승한(Seunghan Oh) 대한치과재료학회 2013 대한치과재료학회지 Vol.40 No.4

The purpose of this study was to evaluate the effect of glycerine on the penetration of coloring liquid on zirconia and hardness of zirconia. Three A2 coloring liquids (Prettau Aquarell Colour liquid, D.max coloring liquid, and Bruxzir coloring liquid) were used to perform this study. Glycerine were mixed with each coloring liquid at the ratio of 1 : 1 by volume. The immersion periods of zirconia specimen in the mixing solution were 1, 3, 6, 9, and 12 hrs, respectively. The penetration depth of coloring liquid were measured by vernier calliper. Color characterization of experimental specimen was performed by spectrophotometer, and hardness of the specimen was measured by Vickers hardness tester. From the results of penetration depth measurement, glycerine was supposed to affect the penetration depth of coloring liquid on zirconia regardless of immersion periods. By color analysis, L^* value of glycerine treated specimen was significantly higher than that of control group(P<0.05), but b^*and ?jE^*values of glycerine treated specimen were significantly lower than that of control group regardless of immersion periods(P>0.05). In terms of the results of Vickers hardness test, there were no significant statistical differences between control group and experimental groups. Therefore, glycerine was expected to affect the penetration of coloring liquid on zirconia and the shade of zirconia.

Silane Coupling Agent가 의치상 수리강화에 미치는 효과

박다령(Da-Ryeong Park),유상희(Sang-Hui Yu),배지명(Ji-Myung Bae),오승한(Seung-Han Oh) 대한치과재료학회 2012 대한치과재료학회지 Vol.39 No.3

The purpose of this study was to evaluate the effect of the surface treatment of silane coupling agents on the reinforcement of repaired denture and find the optimal condition of silane coupling agent showing highest 3-point flexural strength. Base plate was prepared by heat curing denture base resin, and the region to be repaired was fabricated at the form of Butt Joint. Three kinds of silane coupling agent (3-Methacryloxypropyltrimethoxysilane; MPS, Vinyltriethoxy silane; VTS, 3-Aminopropyltriethoxysilane; APS) was added to the monomer of denture repair resin with 0.1, 0.5, 1.0 and 2.0 % of silane coupling agent. The results of 3-point flexural strength showed that the value of 0.5 % MPS experimental group was higher than that of other MPS groups( P<0.05). The value of 3-point flexural strength of 0.1% VTS group was higher than that of other VTS groups( P<0.05). However, there was no significant difference between the values of each APS experimental group( P>0.05). Therefore, we could conclude that the kinds and concentrations of silane coupling agent are supposed to affect the bond of repaired denture and repair resin.

의치상 수리방법이 의치상용 레진의 굴곡강도에 미치는 영향

박다령(Da-Ryeong Park),배지명(Ji-Myung Bae),오승한(Seung-Han Oh) 대한치과재료학회 2011 대한치과재료학회지 Vol.38 No.4

The purpose of this study was to examine the effect of repair method on the flexural strength of repaired denture base resin. Heat cured denture base resin (Vertex RS) was used to prepare denture base substrate based on the protocol of ISO 20795-1:2008. 3 kinds of repair methods (vertical method, 45˚ bevel method, complex method) were adopted to repair fractured denture base substrate, and 3 kinds of denture repair resins (Vertex SC, Luciton 199 Repair, Jet Dental Repair) were used in this study. 3 point flexural strength test was performed to evaluate the mechanical strength of repaired denture base resin in terms of 5 kinds of l oading directions. The f ailure mode of f ractured i nterface was o bserved after testing 3 p oint f lexural strength. With regard to the effect of repair methods, the results of flexural strength test indicated that the value of Inverse-directed complex method was significantly higher than that of other repair methods on the condition of Vertex SC and Luciton 199 Repair resin (P<0.05). However, Jet Dental Repair resin did not show a ny sig nificant d ifference between repair m ethods. From the o bservation of f ailure m ode, v ertical method did not show any unified consistency from the results of 3 denture repair resin. However, complex method indicated more cohesive and complex failure mode resulting in strong bond between denture base substrate and denture repair resin regardless of loading direction. Therefore, complex method among 3 repair methods is expected t o play c ritical role i n enhancing the mechanical streng th o f repaired d enture base resin.

형광영상분석기와 단색색상분석 소프트웨어를 이용한 복합레진의 형광성 평가

박다령(Da-Ryeong Park),김아진(Ah-Jin Kim),배지명(Ji-Myung Bae),오승한(Seung-Han Oh) 대한치과재료학회 2015 대한치과재료학회지 Vol.42 No.2

In the field of dental color research, there are observing color of natural teeth, analysing color spectrum of human natural teeth, researching discoloration of teeth, and researching shade-guide of teeth. However, there is less research for fluorescence which is optical shade than research for the color which can be seen. In this research, fluorescent standard materials in that 7-Diethylamino-4-methylcoumarin which is used universally to fluorescent high polymer dental restoration materials was blended were made in the concentration from 0.01% to 0.1%. 14 kinds of composite resin and fluorescent standard materials were observed on Bio Imaging systems and Fluor chern E which is Fluorescence image analyzer, and fluorescence of specimens was analysed measuring gray level of specimen by Image J and Photoshop which is Monochrome color analysis software. Analysing Standard curve graph, fluorescent concentration of specimen in the fluorescent standard materials concentration between 0.01∼0.1% in composite resin could be calculated. Depending on the combination of fluorescence image analyzer and monochromatic analysis software in all the experimental groups except the Filtek Z250 A3.5, showed a significant difference(P<0.05). Among them, in all experimental groups of GC GRADIA DIRECT, showed the highest difference significance of the fluorescence concentration due to monochromatic analysis software(P<0.05).

CAD/CAM 기법과 프레스 기법으로 제작된 코어의 적합도 평가

박다령(Da-Ryeong Park),오승한(Seunghan Oh) 대한치과재료학회 2016 대한치과재료학회지 Vol.43 No.4

In this study, comparing internal and marginal fit between simplified abutment die and zirconia cores prepared by five CAD/CAM systems vs. one press technique were preformed to (1) estimate the machinability of CAD/CAM systems compared to that of conventional technique and (2) investigate the applicability of simplified abutment die as a standard model for assessing internal and marginal fit assessed by silicone replica technique. The results were evaluated with one-way ANOVA, and the Duncanʹs multiple range test(α=0.05). From all results, Ceramill(46.10 ± 30.57 ㎛) and Cameleon(78.17 ± 20.65 ㎛) showed the best fitness in marginal gap point and cervical area point, respectively. In axio - occlusal angle a rea, Cameleon(52.87 ± 16.77 ㎛) and Luxen(45.45 ± 32.67 ㎛) resulted the best fitness compared to other experimental groups. Also, the internal and marginal gaps of all experimental groups resulted less than 120 ㎛(maximum allowable marginal gap between core and abutment in clinical use) so that all zirconia cores prepared by CAD/CAM system in this study are expected to be suitable for clinical application in dentistry.

섬유의 종류와 배열방향에 따른 상악 총의치의 강화효과

유상희(Sang-Hui Yu),박다령(Da-Ryeong Park),오승한(Seung-han Oh),배지명(Ji-Myung Bae) 대한치과재료학회 2012 대한치과재료학회지 Vol.39 No.1

The fracture of denture base resin occurs due to repeated loading caused by masticatory forces or accidental dropping. One method strengthening denture base resin is the addition of reinforcing fibers to resin. The aim of this study was to evaluate the effect of glass and aramid fibers according to the fiber orientation on maxillary complete denture. In the study of denture model, maxillary complete denture was fabricated with auto-polymerized resin(Vertex SC). Glass fiber and polyaromatic polyamide fiber (aramid) were used in unidirectional and bidirectional orientation to reinforce the maxillary complete denture. The maxillary complete denture without fibers was used as a control. The flexural strengths, moduli and toughness of the denture were measured with and without silicone maxillary cast, respectively. The specimens of each group were stored in distilled water at 37℃ for 50 hours before test, The flexural strengths, moduli and toughness were measured with a universal testing machine at a crosshead speed of 5 ㎜/min in a three-point bending mode. For flexural strengths, there were no significant differences according to the fiber type and orientation. The flexural strength of bidirectional glass fiber and unidirectional aramid fiber with silicone cast denture were significantly higher than those without silicone cast denture. However, the flexural modulus of unidirectional aramid fiber was significantly higher than those of other experimental groups and the control at test without silicone cast. The flexural modulus of unidirectional aramid fiber and bidirectional glass fiber without silicone cast denture were significantly higher than those without silicone cast denture. For the toughness, the bidirectional glass fiber with silicone cast were significantly higher than those of other experimental groups and the control, with the exception of unidirectional aramid fiber. The toughness of control, bidirectional glass fiber and unidirectional aramid fiber with silicone cast denture were significantly higher than those without silicone cast denture. In this study, bidirectional glass fiber and unidirectional aramid fiber showed the significant reinforcing effect on maxillary complete denture in terms of flexural modulus and toughness.

피착재와 자가접착 레진시멘트의 종류에 따른 우치 상아질과의 전단결합강도

김아진(Ah-Jin Kim),박다령(Da-Ryeong Park),오승한(Seunghan Oh),배지명(Ji-Myung Bae) 대한치과재료학회 2015 대한치과재료학회지 Vol.42 No.4

The purpose of this study was to evaluate the shear bond strengths of self-adhesive resin cements that was applied similar to clinical condition between bovine dentin and four types of adherend. The self-adhesive resin cements, which were used in this study, included U-Cem Premium (U-Cem, Vericom), Rely X Unicem II Automix (Rely X, 3M ESPE), Maxcem Elite (Maxcem: Kerr) and Clearfil SA luting Cement (Clearfil, Kuraray). Four types of adherends, which were used in the research, included composite resin block for CAD-CAM (Polyglass Blank, Vericom), base metal (Vera Bond 2V, Albadent), zirconia (Mazic zir, Vericom) and lithium disilicate (IPS E.max, Ivoclar/Vivadent). The block of adherend was made with breadth 3 mm × length 3 mm × height 3 mm. It adhered adherend to bovine dentin, repeated photopolymerization twice by 20 seconds per surface in the status of applying the load in 5 N, added 30minutes to the holding time following the polymerization instructed by a maker, and then kept it in 37°C dry oven. The adhered specimen was kept for 24 hours in 37°C distilled water until before the experiment. The shear bond strength was measured with 0.75 mm/min cross-head speed by using a universal testing machine(Z020, Zwick, Ulm, Germany). The blade of the used jig was a straight line. The bond strength with resin adherend was the highest in Rely X. U-cem and Clearfil were significantly higher than Maxem.(p<0.05). As for the bond strength with zirconia, Rely X and U-Cem were significantly higher than other self-adhesive resin cements(p<0.05). In terms of the bond strength with metal and lithium disilicate, Rely X, U-Cem, Clearfil were significantly higher than Maxcem(p<0.05). Hence, Rely X is recommended to the adhesion with the composite resin adherend. Rely X and U-Cem are recommended to the adhesion of zirconia. Maxem, which shows the lowest bond strength in all adherends, needs to be paid a great attention given being used in a clinical trial.

Effect of core surface treatment on the fracture resistance of zirconia restoration

Su-Ha Jeoung(정수하),Jeong-mi Kim(김정미),Da-Ryeong Park(박다령),Ji-Young Park(박지영),Ji-Myung Bae(배지명),Seung-Han Oh(오승한) 대한치과재료학회 2014 대한치과재료학회지 Vol.41 No.3

The purpose of this study was to examine the effect of acid-base surface treatment on the fracture resistance, which is one of main mechanical property, of zirconia restoration in order to improve the bonding characterization between zirconia core and ceramic veneer in bi-layered all ceramic restoration system. 10% hydrofluoric acid (HF) and 1 M sodium hydroxide (NaOH) were used as acid and base chemical solutions for surface treatment, respectively. Fracture-resistance tests were performed to investigate the effects of acid and liner treatment on the improvement of the bonding strength between veneer ceramics and zirconia. Specimens were divided into five groups (n = 4) according to the type of surface treatment: (1) Group A, no treatment (control); (2) Group B, liner treatment; (3) Group C, 10% HF etching for 60 s; (4) Group D, 10% HF etching for 60 s and liner treatment. All results of fracture resistance test showed that there were no significant differences between surface treatment types. Failure mode observation indicated that most specimens of Cerasys, Zmatch, and ICE groups showed cohesive failure mode regardless of the method of surface treatment. From the results of study, the short (1 min) treatment of zirconia in HF solution is supposed to be suitable for improving bond strength of zirconia restoration, but long (more than 30 min) treatment of zirconia in HF solution is expected to deteriorate the zirconia structure. Also, several factors such as liner and acid treatment, which improve the fracture resistance of zirconia restoration, seemed to depend on the type of zirconia materials.

지르코니아 표면 처리와 인공타액의 pH에 따른 지르코니아와 레진시멘트의 전단결합강도

신성진(Seong-Jin Shin),오동석(Dong-Suk Oh),박다령(Da-Ryeong Park),오승한(Seung-Han Oh),배지명(Ji-Myung Bae) 대한치과재료학회 2016 대한치과재료학회지 Vol.43 No.4

Surface treatment of zirconia is important for the adhesion with adhesive resin cement. Solubility of resin cement is affected to the intraoral pH condition. The aim of the present study was to evaluate the effect of the pH of artificial saliva and the surface treatment of zirconia on shear bond strengths between zirconia and resin cement. Zirconia blocks (Mazic Zir, Vericom) were sintered at 1500˚C for 2 hours. The surface of zirconia was treated by sandblasting (SB), 48% hydrofluoric acid (HF), and combination of sandblasting and HF (SB+HF). Self-adhesive resin cement (Rely X U200, 3M ESPE) was applied on the zirconia surface and the specimens were stored under the different pH of 4, 7 and 10 at 37˚C for 24 hours. The shear bond strengths between zirconia and resin cement were measured with a universal testing machine (Z020, Zwick) at a cross-head speed of 1 mm/min. Results were statistically analyzed with two-way ANOVA, Kruskall-Wallis test, Duncan’s multiple range test (α=0.05) and Pearson correlation analysis. The shear bond strengths were significantly affected by different surface treatments and by pH conditions (P<0.05). For the surface treatment of zirconia, the shear bond strengths of SB+HF were higher than other groups (P<0.05). For pH condition, DW, pH4 and pH7 showed higher shear bond strengths than pH 10 (P<0.05). Therefore, when an adhesive resin cement is applied to a zirconia surface, it is recommended to treat the zirconia with sandblasting followed by HF etching.