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Effect of acrolein-based primer as collagen cross-linker on dentin adhesion
d e n t a l m a t e r i a l s 3 3 S ( 2 0 1 7 ) e1–e92
39 Improvement of physical properties of MTA incorporated by ELP J.-Y. Choi ∗ , H.-J. Kim, C.-O. Lee, S. Oh, S.-Y. Kim Department of Conservative Dentistry, Kyung Hee University, Seoul, Republic of Korea Purpose/aim: The aim of this study is to investigate the effect of elastin-like polypeptide (ELP) based matrix on the physical properties of MTA. Materials and methods: ELP synthesis: The pET28b vectors containing ELP sequences synthesized by genetic engineering were expressed in E. coli BLR (DE3) bacteria. The elastin-like polypeptide (ELP; V125, V125-E8) was then purified. The 10 wt% ELP solution was made with deionized water. Microhardness: Samples were prepared by mixing MTA (ProRoot MTA; Dentsply Tulsa Dental, OK) powder with three types of liquid (deionized water, 10 wt% V125, 10 wt% V125E8). Microhardness was measured with Vickers tester (HMV-2, Shimadzu Corp., Tokyo, Japan). Compressive strength: Each mixed sample was immediately transferred into the Teflon molds (3.0 mm in diameter and 7.0 mm in height) and compressive strength was then measured by using a universal tester (UH-X, Shimadzu Corp., Tokyo, Japan) at 0.5 mm/min of speed. Anti-wash out: The specimen placed into a simulated body fluid (HEPES) at 37 ◦ C. After shaking the three specimens for 5 min, 1 h, and 24 h, washout ratio of the specimen was evaluated by measuring the weight. Results: Microhardness, Compressive strength: As L/P decreased, the value of microhardness and compressive strength increased. At all L/P ratios, values were given in order of V125E8 > V125 > DW (P < 0.05). Anti-wash out: After 24 h, washout resistance of the samples increased in order of MTA + DW, MTA + V125, and MTA + V125E8 (P < 0.05). Conclusions: The ELP supplemented MTA showed a significantly enhanced handling property, microhardness, compressive strength, anti-washout property. This study indicates that ELP can be used to develop the inorganic dental repairing cement to have improved physical properties. http://dx.doi.org/10.1016/j.dental.2017.08.040
are a class of zinc- and calcium-dependent endopeptidases that are trapped within the mineralized dentin matrix during tooth development. Since type I collagen fibril network represents the backbone of dentin, the collagenolytic/gelatinolytic activity of these endogenous enzymes has been shown to be responsible for the in vitro and in vivo hybrid layer degradation causing slow hydrolysis of collagen fibrils over time. The aim of this study was to evaluate the effect of an acrolein-based primer pretreatment, used as a cross-linker, on the hybrid layer created by a two-step etch-and-rinse adhesive system. Materials and methods: Dentin surfaces were etched with 35% phosphoric acid for 15 s, rinsed and blot dried. Specimens were then assigned to: Group 1: dentin was pretreated with 0.01% acrolein (ACR) water solution for 1 min, then bonded with Adper Scotchbond 1 XT (SB1XT), a 2-step etch-and-rinse adhesive system; Group 2: SB1XT was applied on untreated etched dentin (control group). Composite buildups were made using Filtek Z250. Specimens were subjected to microtensile bond strength test and stressed to failure immediately or after 1 year of storage in artificial saliva at 37 ◦ C. To investigate dentinal matrix metalloproteinase activity (MMPs), zymographic assay was also performed on protein extracts obtained from etched dentin powder treated with or without ACR before SB1XT adhesive application. Finally, in situ zymographic assay was performed to investigate endogenous MMPs activity within the hybrid layer in accordance with Mazzoni et al., 2014. Results were statistically analyzed with ANOVA tests and statistical significance was set for p < 0.05. Results: The use of 0.01% ACR as conditioning primer did not affect immediate bond strength (Group 1: 44.6 ± 14.2 MPa; Group 2: 40.1 ± 8.2 MPa) but contributed to stabilizing bond strength over time. After 1yr storage in artificial saliva, ACR bonded specimens showed no significant reduction of bond strength (Group 1: 46.4 ± 6.1 MPa), while the control group resulted in significant loss of bond strength values. Zymographic and in situ zymographic assays showed that when acrolein was used before adhesive application, dentinal MMPs activity was significantly reduced. Conclusions: Dentinal collagen cross-linking induced by acrolein-based primer increased the durability of resin–dentin bonds by the reinforcement of the adhesive interface and inhibition of dentinal MMPs. Further studies are needed to evaluate the potential acrolein cytotoxicity both in vitro and in vivo.
40 Effect of acrolein-based primer as collagen cross-linker on dentin adhesion A. Comba 1,∗ , T. Maravic 1 , A. Mazzoni 1 , M. Cadenaro 2 , C. Nucci 1 , N. Scotti 3 , L. Breschi 1 1
DIBINEM, University of Bologna, Italy University of Trieste, Italy 3 University of Turin, Department of Surgical Sciences, Dental School, Italy 2
Purpose/aim: In adhesive dentistry, the stability and integrity of collagen fibrils within the hybrid layer is crucial for the maintenance of bond effectiveness over time. MMPs
e21
http://dx.doi.org/10.1016/j.dental.2017.08.041
39 Improvement of physical properties of MTA incorporated by ELP J.-Y. Choi ∗ , H.-J. Kim, C.-O. Lee, S. Oh, S.-Y. Kim Department of Conservative Dentistry, Kyung Hee University, Seoul, Republic of Korea Purpose/aim: The aim of this study is to investigate the effect of elastin-like polypeptide (ELP) based matrix on the physical properties of MTA. Materials and methods: ELP synthesis: The pET28b vectors containing ELP sequences synthesized by genetic engineering were expressed in E. coli BLR (DE3) bacteria. The elastin-like polypeptide (ELP; V125, V125-E8) was then purified. The 10 wt% ELP solution was made with deionized water. Microhardness: Samples were prepared by mixing MTA (ProRoot MTA; Dentsply Tulsa Dental, OK) powder with three types of liquid (deionized water, 10 wt% V125, 10 wt% V125E8). Microhardness was measured with Vickers tester (HMV-2, Shimadzu Corp., Tokyo, Japan). Compressive strength: Each mixed sample was immediately transferred into the Teflon molds (3.0 mm in diameter and 7.0 mm in height) and compressive strength was then measured by using a universal tester (UH-X, Shimadzu Corp., Tokyo, Japan) at 0.5 mm/min of speed. Anti-wash out: The specimen placed into a simulated body fluid (HEPES) at 37 ◦ C. After shaking the three specimens for 5 min, 1 h, and 24 h, washout ratio of the specimen was evaluated by measuring the weight. Results: Microhardness, Compressive strength: As L/P decreased, the value of microhardness and compressive strength increased. At all L/P ratios, values were given in order of V125E8 > V125 > DW (P < 0.05). Anti-wash out: After 24 h, washout resistance of the samples increased in order of MTA + DW, MTA + V125, and MTA + V125E8 (P < 0.05). Conclusions: The ELP supplemented MTA showed a significantly enhanced handling property, microhardness, compressive strength, anti-washout property. This study indicates that ELP can be used to develop the inorganic dental repairing cement to have improved physical properties. http://dx.doi.org/10.1016/j.dental.2017.08.040
are a class of zinc- and calcium-dependent endopeptidases that are trapped within the mineralized dentin matrix during tooth development. Since type I collagen fibril network represents the backbone of dentin, the collagenolytic/gelatinolytic activity of these endogenous enzymes has been shown to be responsible for the in vitro and in vivo hybrid layer degradation causing slow hydrolysis of collagen fibrils over time. The aim of this study was to evaluate the effect of an acrolein-based primer pretreatment, used as a cross-linker, on the hybrid layer created by a two-step etch-and-rinse adhesive system. Materials and methods: Dentin surfaces were etched with 35% phosphoric acid for 15 s, rinsed and blot dried. Specimens were then assigned to: Group 1: dentin was pretreated with 0.01% acrolein (ACR) water solution for 1 min, then bonded with Adper Scotchbond 1 XT (SB1XT), a 2-step etch-and-rinse adhesive system; Group 2: SB1XT was applied on untreated etched dentin (control group). Composite buildups were made using Filtek Z250. Specimens were subjected to microtensile bond strength test and stressed to failure immediately or after 1 year of storage in artificial saliva at 37 ◦ C. To investigate dentinal matrix metalloproteinase activity (MMPs), zymographic assay was also performed on protein extracts obtained from etched dentin powder treated with or without ACR before SB1XT adhesive application. Finally, in situ zymographic assay was performed to investigate endogenous MMPs activity within the hybrid layer in accordance with Mazzoni et al., 2014. Results were statistically analyzed with ANOVA tests and statistical significance was set for p < 0.05. Results: The use of 0.01% ACR as conditioning primer did not affect immediate bond strength (Group 1: 44.6 ± 14.2 MPa; Group 2: 40.1 ± 8.2 MPa) but contributed to stabilizing bond strength over time. After 1yr storage in artificial saliva, ACR bonded specimens showed no significant reduction of bond strength (Group 1: 46.4 ± 6.1 MPa), while the control group resulted in significant loss of bond strength values. Zymographic and in situ zymographic assays showed that when acrolein was used before adhesive application, dentinal MMPs activity was significantly reduced. Conclusions: Dentinal collagen cross-linking induced by acrolein-based primer increased the durability of resin–dentin bonds by the reinforcement of the adhesive interface and inhibition of dentinal MMPs. Further studies are needed to evaluate the potential acrolein cytotoxicity both in vitro and in vivo.
40 Effect of acrolein-based primer as collagen cross-linker on dentin adhesion A. Comba 1,∗ , T. Maravic 1 , A. Mazzoni 1 , M. Cadenaro 2 , C. Nucci 1 , N. Scotti 3 , L. Breschi 1 1
DIBINEM, University of Bologna, Italy University of Trieste, Italy 3 University of Turin, Department of Surgical Sciences, Dental School, Italy 2
Purpose/aim: In adhesive dentistry, the stability and integrity of collagen fibrils within the hybrid layer is crucial for the maintenance of bond effectiveness over time. MMPs
e21
http://dx.doi.org/10.1016/j.dental.2017.08.041