• Title/Summary/Keyword: Flowable composite

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A NEW METHOD TO MEASURE THE LINEAR POLYMERIZATION SHRINKAGE OF COMPOSITES USING A PARTICLE TRACKING METHOD WITH COMPUTER VISION (컴퓨터 시각과 입자 추적 방법을 이용한 복합레진의 선형중합수축 측정의 새로운 방법)

  • Lee, In-Bog;Min, Sun-Hong;Seo, Deog-Gyu;Kim, Sun-Young;Kwon, Young-Chul
    • Restorative Dentistry and Endodontics
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    • v.35 no.3
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    • pp.180-187
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    • 2010
  • Since the introduction of restorative dental composites, their physical properties have been significantly improved. However, polymerization shrinkage is still a major drawback. Many efforts have been made to develop a low shrinking composite, and silorane-based composites have recently been introduced into the market. In addition, many different methods have been developed to measure the polymerization shrinkage. In this study, we developed a new method to measure the linear polymerization shrinkage of composites without direct contact to a specimen using a particle tracking method with computer vision. The shrinkage kinetics of a commercial silorane-based composite (P90) and two conventional methacrylate-based composites (Z250 and Z350) were investigated and compared. The results were as follows: 1. The linear shrinkage of composites was 0.33-1.41%. Shrinkage was lowest for the silorane-based (P90) composite, and highest for the flowable Z350 composite. 2. The new instrument was able to measure the true linear shrinkage of composites in real time without sensitivity to the specimen preparation and geometry.

Evaluation of polymerization ability of resin-based materials used for teeth splinting (레진계 치아 스플린팅 재료들의 중합능력 평가)

  • Lee, Jeong-Gil;Kim, Soo-Yeon;Lee, Jae-Kwan;Kim, Jin-Woo;Park, Se-Hee;Cho, Kyung-Mo
    • Journal of Dental Rehabilitation and Applied Science
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    • v.34 no.4
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    • pp.290-296
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    • 2018
  • Purpose: The aim of this study was to evaluate the polymerization ability of resin-based materials used for teeth splinting according to the thickness of cure. Materials and Methods: For this study, the Light-Fix and G-FIX developed for resinous splinting materials and the G-aenial Universal Flo, the high-flowable composite resin available as restorative and splinting material, were used. Ten specimens of the thickness of 2, 3, 4 and 5 mm and 5 mm in diameter for each composite resin (total 120) were prepared. The microhardness of top and bottom surfaces for each specimen was measured by the Vickers hardness testing machine. The polymerization ability of the composite resin for each thickness was statistically analyzed using independent T-test at a 0.05 level of significance. Results: There was no difference of polymerization ability regardless of the thickness in the Light-Fix and G-FIX. The G-aenial Universal Flo showed significantly low polymerization ability from the thickness of the 3 mm (P < 0.05). Conclusion: The Light-Fix and G-FIX, which are resin-based materials used for teeth splinting, are expected to be suitable for light curing up to 5 mm in thickness.

Fracture Resistance of Incisal Tooth Fragment reattached with different Materials and Preparation (레진재료와 치아형성 방법에 따른 파절편 재부착치아의 파절저항성)

  • Kim, Jongsung;Kim, Gimin;Lee, Jaesik;Kim, Hyunjung;Nam, Soonhyeun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.49 no.1
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    • pp.104-112
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    • 2022
  • The purpose of this study is to analyze the fracture resistance of reattached tooth according to the resin materials and tooth preparation type under physiological conditions. Uncomplicated crown fracture in the oblique direction was reproduced on the extracted 64 anterior teeth. Depending on the composite resin material, reattachment was performed using a flowable resin and a packable resin. Depending on retentive forms, reattachment was performed using simple reattachment, 1.0 mm × 1.0 mm labial chamfer bevel, 1.0 mm × 1.0 mm lingual chamfer bevel and 1.0 mm × 1.0 mm circumferential bevel. A load was applied to the palatal surface of the tooth using a universal testing machine at an angle of 125 degree, which is the interincisal angle of normal children. Under the masticatory pressure condition, fracture resistance of lingual chamfer groups was 28.28 ± 7.41 MPa and 27.54 ± 4.45 MPa, which was significantly higher than those of simple reattachment groups, 17.21 ± 5.87 MPa and 20.10 ± 6.00 MPa, in both flowable and packable resin groups. When considering the lingual force similar to masticatory pressure, the fragment retention was significantly improved when the lingual chamfer was formed compared to the simple reattachment. Clinicians may consider the design of the lingual chamfer in order to improve fracture resistance to masticatory pressure during fragment reattachment.

Evaluation of Cavity Wall Adaptation of Bulk-fill Resin Composites in Class II Cavities of Primary Molar (유구치 2급 와동에서 bulk-fill 복합레진의 와동적합성 평가)

  • Bae, Youngeun;Shin, Jonghyun;Kim, Shin;Jeong, Taesung;Kim, Jiyeon
    • Journal of the korean academy of Pediatric Dentistry
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    • v.44 no.4
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    • pp.446-454
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    • 2017
  • Recently, there have been many studies on bulk-fill resin composites. However, studies on the proper materials for pediatric patients are rare. The aim of this study was to compare the cavity wall adaptation of bulk-fill resin composites with conventional resin composite in class II cavities of primary molars using microcomputed tomography (micro-CT). Standardized class II slot cavities were prepared in 80 exfoliated primary molars and randomly divided into 4 groups. The control group was restored with conventional resin composite, Filtek Z-350 XT (FZ), and the three groups were restored with bulk-fill resin composites, Filtek bulk-fill posterior (FB), Tetric N-Ceram Bulk Fill (TNC), Filtek bulk-fill flowable (FBF). All specimens were thermocycled and then immersed in 50% silver nitrate ($AgNO_3$) solution. Micro-CT was used to measure the penetration volume of the total silver nitrate and the degree of cervical marginal leakage and the number, size, and position of the voids were evaluated. The results revealed that the volume of silver nitrate were significantly different between FB and FZ (p < 0.05). The results also revealed that the penetration length of silver nitrate FBF showed statistically lower than the FZ and FB (p < 0.05). There was no significant difference between the groups in number and size of voids. In conventional resin composite, most of the voids were present inside the restoration (83.3%), but the voids in the bulk-fill resin composites incidence were higher in the gingivoaxial angle. The cavity wall adaptation demonstrated in class II restorations of primary molar by new bulk fill resin composites was similar to conventional incremental technique. Bulk-fill resin composites might be an clinical option for a faster restoration in deciduous teeth.

EFFECT OF STEP CURING ON THE CONTRACTION STRESS AND MARGINAL ADAPTATION OF RESIN RESTORATION (단계별 광중합 방식이 복합레진 수복물의 수축 응력과 변연 접합도에 미치는 영향)

  • Park, Jong-Whi;Lee, Nan-Young;Lee, Sang-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.33 no.2
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    • pp.221-232
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    • 2006
  • The purpose of this study was to investigate the effect of step-curing mode on polymerization shrinkage and contraction of composite resin restoration. Class I cavities were prepared on the extracted human premolars. The cavities were ailed with Filtek $Z-250^{TM}$ (hybrid resin, 3M ESPE, USA) and Filtek $flow^{TM}$ (flowable resin, 3M ESPE, USA) and cured with one of the following irradiation modes; Halogen 40sec with continuous curing, LED 10sec with continuous curing, and LED 13sec with step-curing. Contraction stress was measured with strain gauge which was connected to TML $Datalogger^{TM}$ (TDS-102, SOKKI, Japan) and resin-dentin interfaces were observed by scanning electron microscope. The results of present study can be summarized as follows : 1. Composite resin restoration showed transient expansion just after irradiation of curing light. Contraction stress was increased rapidly at the early phase of polymerization and reduced slowly as time elapsed (P<0.05) 2. $Filtek\;flow^{TM}$ showed lower contraction stress than Filtek $Z-250^{TM}$ regardless of curing modes. 3. LED step-curing mode showed lowest contraction stress in Filtek $Z-250^{TM}$ compared with other curing modes(P<0.05). 4. LED step-curing mode showed lowest contraction stress in $Filtek\;flow^{TM}$ compared with other curing modes(P<0.05), but difference in contraction stress was not so greate as in $Filtek\;Z-250^{TM}$. 5. Polymerization of composite resin by LED light with step-curing mode and halogen light with continuous ode resulted in better marginal sealing than LED light with continuous mode.

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EFFECT OF INSTRUMENT COMPLIANCE ON THE POLYMERIZATION SHRINKAGE STRESS MEASUREMENTS OF DENTAL RESIN COMPOSITES (측정장치의 compliance 유무가 복합레진의 중합수축음력의 측정에 미치는 영향)

  • Seo, Deog-Gyu;Min, Sun-Hong;Lee, In-Bog
    • Restorative Dentistry and Endodontics
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    • v.34 no.2
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    • pp.145-153
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    • 2009
  • The purpose of this study was to evaluate the effect of instrument compliance on the polymerization shrinkage stress measurements of dental composites. The contraction strain and stress of composites during light curing were measured by a custom made stress-strain analyzer, which consisted of a displacement sensor, a cantilever load cell and a negative feedback mechanism. The instrument can measure the polymerization stress by two modes: with compliance mode in which the instrument compliance is allowed, or without compliance mode in which the instrument compliance is not allowed. A flowable (Filtek Flow: FF) and two universal hybrid (Z100: Z1 and Z250: Z2) composites were studied. A silane treated metal rod with a diameter of 3.0 mm was fixed at free end of the load cell, and other metal rod was fixed on the base plate. Composite of 1.0 mm thickness was placed between the two rods and light cured. The axial shrinkage strain and stress of the composite were recorded for 10 minutes during polymerization. and the tensile modulus of the materials was also determined with the instrument. The statistical analysis was conducted by ANOVA. paired t-test and Tukey's test (${\alpha}<0.05$). There were significant differences between the two measurement modes and among materials. With compliance mode, the contraction stress of FF was the highest: 3.11 (0.13). followed by Z1: 2.91 (0.10) and Z2: 1.94 (0.09) MPa. When the instrument compliance is not allowed, the contraction stress of Z1 was the highest: 17.08 (0.89), followed by FF: 10.11 (0.29) and Z2: 9.46 (1.63) MPa. The tensile modulus for Z1, Z2 and FF was 2.31 (0.18), 2.05 (0.20), 1.41 (0.11) GPa, respectively. With compliance mode. the measured stress correlated with the axial shrinkage strain of composite: while without compliance the elastic modulus of materials played a significant role in the stress measurement.

Stress distribution of Class V composite resin restorations: A three-dimensional finite element study (5급 복합레진수복물의 응력분포에 관한 3차원 유한요소법적 연구)

  • Park, Jeong-Kil;Hur, Bock;Kim, Sung-Kyo
    • Restorative Dentistry and Endodontics
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    • v.33 no.1
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    • pp.28-38
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    • 2008
  • This study was to investigate the influence of composite resins with different elastic modulus, cavity modification and occlusal loading condition on the stress distribution of restored notch-shaped noncarious cervical lesion using 3-dimensional (3D) finite element (FE) analysis. The extracted maxillary second premolar was scanned serially with Micro-CT. The 3D images were processed by 3D-DOCTOR. ANSYS was used to mesh and analyze 3D FE model. A notch-shaped cavity and a modified cavity with a rounded apex were modeled. Unmodified and modified cavities were filled with hybrid or flowable resin. After restoration, a static load of 500N was applied in a point-load condition at buccal cusp and palatal cusp. The stress data were analyzed using analysis of principal stress. The results were as follows: 1. In the unrestored cavity, the stresses were highly concentrated at mesial CEJ and lesion apex and the peak stress was observed at the mesial point angle under both loading conditions. 2. After restoration of the cavity, stresses were significantly reduced at the lesion apex, however cervical cavosurface margin, stresses were more increased than before restoration under both loading conditions. 3. When restoring the notch-shaped lesion, material with high elastic modulus worked well at the lesion apex and material with low elastic modulus worked well at the cervical cavosurface margin. 4. Cavity modification the rounding apex did not reduce compressive stress, but tensile stress was reduced.

EFFECT OF VARIOUS LINERS ON THE POLYMERIZATION SHRINKAGE OF COMPOSITE RESIN (수종의 이장재가 복합레진의 중합수축에 미치는 영향)

  • Choi, Ji-Won;Lee, Sang-Ho;Lee, Nan-Young
    • Journal of the korean academy of Pediatric Dentistry
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    • v.33 no.4
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    • pp.606-614
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    • 2006
  • The purpose of this study was to evaluate the polymerization contraction of composite resin(Tetric $ceram^{(R)}$, Ivoclar Vivadent Liechtenstein) according to various liners(Tetric $flow^{(R)}$, Ivoclar Vivadent, Liechtenstein/$Ionosit^{(R)}$, DMG, German/ $Vitrebond,^{TM}$ 3M-ESPE, USA). The strain gauge method was used for measurement of polymerization shrinkage strain. Specimens were divided by 8 groups according to curing units and liners. Group A, E: Tetric $ceram^{(R)}$ bulk filing, Group B, F: Tetric $flow^{(R)}$ lining, Tetric $ceram^{(R)}$ filling, Group C, G: $Ionosit^{(R)}$ lining, Tetric $ceram^{(R)}$ filling, Group D, H: $Vitrebond^{TM}$ lining, Tetric $ceram^{(R)}$ filling. Group A, B, C and D were cured using the conventional halogen light($XL3000^{TM}$ 3M ESPE, USA) for 40 seconds at $400mW/cm^2$. Group E, F G and H were cured using light emitted diode(LED) light(Elipar Freelight $2^{TM}$, 3M-ESPE, USA) for 15 seconds at 800 $mW/cm^2$. Strain gauge attached to each sample was connected to a strainmeter. Measurements were recorded at each second for the total of 750 seconds including the periods of light application. Obtained data were analyzed statistically using Repeated measures ANOVA and Tukey test. The results of this were as follows : 1. Contraction stresses in flowable resin and glass ionomer lining group were lower than that in compomer lining group(p<0.05). 2, Contraction stresses in LED curing light groups were higher than that in halogen curing light groups, but there was no significant difference (p>0.05).

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The influence of combining composite resins with different elastic modulus on the stress distribution of class V restoration: A three-dimensional finite element study (탄성계수가 다른 복합레진의 혼합수복이 5급 수복물의 응력분포에 미치는 영향에 관한 3차원 유한요소법적 연구)

  • Park, Jeong-Kil;Hur, Bock;Kim, Sung-Kyo
    • Proceedings of the KACD Conference
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    • 2008.05a
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    • pp.184-197
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    • 2008
  • This study was to investigate the influence of combining composite resins with different elastic modulus, and occlusal loading condition on the stress distribution of restored notch-shaped non-carious cervical lesion using 3D finite element (FE) analysis. The extracted maxillary second premolar was scanned serially with Micro-CT. The 3D images were processed by 3D-DOCTOR. ANSYS was used to mesh and analyze 3D FE model. A notch-shaped cavity was modeled and filled with hybrid, flowable resin or a combination of both. After restoration, a static load of 500N was applied in a point-load condition at buccal cusp and palatal cusp. The stress data were analyzed using analysis of principal stress. Results showed that combining method such that apex was restored by material with high elastic modulus and the occlusal and cervical cavosurface margin by small amount of material with low elastic modulus was the most profitable method in the view of tensile stress that was considered as the dominant factor jeopardizing the restoration durability and promoting the lesion progression.

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The influence of combining composite resins with different elastic modulus on the stress distribution of class V restoration: A three-dimensional finite element study (탄성계수가 다른 복합레진의 혼합수복이 5급 수복물의 응력분포에 미치는 영향에 관한 3차원 유한요소법적 연구)

  • Park, Jeong-Kil;Hur, Bock;Kim, Sung-Kyo
    • Restorative Dentistry and Endodontics
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    • v.33 no.3
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    • pp.184-197
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    • 2008
  • This study was to investigate the influence of combining composite resins with different elastic modulus, and occlusal loading condition on the stress distribution of restored notch-shaped non-carious cervical lesion using 3D finite element (FE) analysis. The extracted maxillary second premolar was scanned serially with Micro-CT. The 3D images were processed by 3D-DOCTOR. ANSYS was used to mesh and analyze 3D FE model. A notch-shaped cavity was modeled and filled with hybrid, flowable resin or a combination of both. After restoration, a static load of 500N was applied in a point-load condition at buccal cusp and palatal cusp. The stress data were analyzed using analysis of principal stress. Results showed that combining method such that apex was restored by material with high elastic modulus and the occlusal and cervical cavosurface margin by small amount of material with low elastic modulus was the most profitable method in the view of tensile stress that was considered as the dominant factor jeopardizing the restoration durability and promoting the lesion progression.