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Physicochemical properties of epoxy resin-based root canal sealers
d e n t a l m a t e r i a l s 3 0 S ( 2 0 1 4 ) e1–e180
(p > 0.05). Regarding the qualitative analysis, there were a larger number of cracks in the final specimens of MTA Fillapex and loss of structure in the specimens of all sealers. The spectrometry results showed significantly (p < 0.05) greater release of Ca2+ , K+ and Na+ ions from MTA Fillapex and Zn2+ ions from Endofill. Conclusion: AH Plus and Endofill fulfilled the ANSI/ADA recommendations for solubility when the percentage of mass variation was analyzed and presented lower volumetric variation and ion release. It may be suggested that CT and atomic absorption spectrometry are important research tools to complement the solubility test.
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Results: The addition of rhodamine at 0.05% (426.20 ± 1.30) and 0.01% (422.00 ± 7.58) concentrations did not alter the setting time of AH Plus pure (468.00 ± 10.20), being similar to each other (p > 0.05). For the flow, no statistically significant difference (p > 0.05) was observed between AH Plus pure (38.51 ± 0.36) and added with the fluorescent agent at 0.1% (43.15 ± 0.70), 0.05% (40.39 ± 1.42) and 0.01% (38.32 ± 0.47). For the solubility test, only the 0.01% concentration (0.49 ± 0.06) was statistically similar (p > 0.05) to AH Plus pure (0.21 ± 0.10). Regarding the addition of fluorescein, the 0.01% concentration presented statistically similar (p > 0.05) setting time (480.84 ± 17.44) and solubility (0.25 ± 0.10) to those
Keywords: Solubility; MicroCT; Root canal sealers
http://dx.doi.org/10.1016/j.dental.2014.08.121 121 Influence of fluorescent agents on physicochemical properties of resin sealer F.J.A. Rached-Júnior ∗ , M.A.L. Ferraz, L.M. Macedo, C.S. Miranda, Y.T.C. Silva-Sousa University of Ribeirão Preto, School of Dentistry, Ribeirão Preto, SP, Brazil Purpose: The objective of this study was to assess whether the addition of the fluorescent agents rhodamine and fluorescein, used in confocal laser microscopy, alters the physicochemical properties of AH Plus epoxy resin-based sealer. Methods and materials: Samples of AH Plus epoxy resinbased sealer, pure and with addition of the fluorescent agents rhodamine and fluorescein at 0.1%, 0.05% and 0.01% concentrations, were prepared for evaluation of the setting time, flow and solubility, in accordance with ANSI/ADA Specification 57. To determine the setting time, molds (10 mm diameter and 2 mm thick) were filled with cement. After 150 s, the cements were tested with a Gilmore needle (100 g), every 60 s until no more indentations on the surface were found. For the flow test, 0.5 mL of cement was placed on a glass plate and, after 180 s, another plate and additional weight was placed over the sealer (total 120 g). After 10 min, the larger and smaller diameter of the formed discs was measured. For the solubility test, 10 specimens (1.5 mm thick and 7.75 mm diameter) were prepared for each group. After weighing two specimens at a time, they were immersed in 7.5 mL of distilled water for 7 days and weighed again, to determine the percentage of mass loss. Data were subjected to ANOVA and Tukey’s test (a = 5%).
of AH Plus pure (468 ± 10.20 and 0.21 ± 0.10, respectively). Regarding the flow, the addition of 0.05% (35.50 ± 1.09) and 0.01% (36.99 ± 1.48) concentrations resulted in similar results (p > 0.05) to those of AH Plus (38.36 ± 0.36). Conclusion: It may be concluded that the addition of the fluorescent agents rhodamine and fluorescein at 0.01% concentration did not alter the setting time, flow and solubility of AH Plus epoxy resin-based sealer. Keywords: Endodontics; Physicochemical properties; Fluorescent agents http://dx.doi.org/10.1016/j.dental.2014.08.122 122 Physicochemical properties of epoxy resin-based root canal sealers G.B. Leoni 1,∗ , J.F.M. Chaves 1 , B.M. Crozeta 1 , V.L.C. Araújo 1 , R.P.F. Rosa 1 , F.J.A. Rached-Junior 2 , Y.T.C. Silva-Sousa 2 , M.D. Sousa-Neto 1 1 2
University of Sao Paulo, Brazil University of Ribeirao Preto, Brazil
Purpose: The aim of this study was to evaluate the following physicochemical properties of the epoxy resin-based root canal sealers MM Seal and AH Plus, according to the ANSI/ADA standards: setting time (ST), flow (F), radiopacity (RP), dimensional change (DC) and solubility (SB). Methods and materials: For analysis of ST, the sealers were placed inside cylindrical stainless steel molds and tested with a Gilmore needle (100 g). For F, the sealers were placed on a glass plate and, 180 s after start of mixing, another plate with 120 g mass was pressed against the material. Diameters were
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d e n t a l m a t e r i a l s 3 0 S ( 2 0 1 4 ) e1–e180
Table 1 – Physical properties of the sealers (mean ± standard deviation). MM Seal Setting time (min) Flow (mm) Radiopacity (mm Al) Dimensional change (%) Solubility (%)
72.60 52.75 2.32 8.47 0.94
± ± ± ± ±
AH Plus 1
4.39 0.601 0.901 2.411 0.171
463.6 36.42 7.52 0.06 0.41
± ± ± ± ±
13.222 0.402 1.592 0.122 0.212
Lowercase letters indicate statistically significant difference in columns (p < 0.05).
recorded 10 minutes after the start of mixing. For RP, the sealers were placed inside circular Teflon molds, radiographed and the radiographic density (mm Al) was measured using Digora software. For DC, the sealers were placed inside cylindrical molds, measured for length, immersed in distilled water for 30 days, dried and measured again to determine the percentage of the dimensional alterations. For SB, circular molds were filled with the sealers, weighed, immersed in water, reweighed after 7 days, and the liquids were analyzed by atomic absorption spectrometry. Data were analyzed statistically by ANOVA and Tukey’s test (a = 5%). Results: The ST means for MM Seal and AH Plus were 72.60 ± 4.39 and 463.6 ± 13.22, respectively. The F means for MM Seal and AH Plus were 52.75 ± 0.60 and 36.42 ± 0.40, respectively. For RP, AH Plus presented higher mean value (7.52 ± 1.59) than MM Seal (2.32 ± 0.90). For DC (MM Seal 8.47 ± 2.41; AH Plus 0.06 ± 0.12) and SB (MM Seal 0.94 ± 0.17; AH Plus 0.41 ± 0.21), AH Plus presented better results. There was statistically significant difference between the sealers for the physicochemical properties ST, F, RP, DC and SB, with lower F, DC and SB values for AH Plus (p < 0.05). The results of the atomic absorption spectrometry showed greater release of Ca2+ , K+ , Na+ , Ni+ and Zn2+ ions from MM Seal (p < 0.05) (Table 1). Conclusion: Only AH Plus fulfilled all ANSI/ADA recommendations relative to the physicochemical properties evaluated in this study. Keywords: Epoxy resin-based sealer; Root canal sealers; Physical properties http://dx.doi.org/10.1016/j.dental.2014.08.123 123 Flexural strength of bis-acrylic resin reinforced with experimental nylon fiber T.J.A. Paes-Junior ∗ , H. Yamada, C.S. Almeida, R.N. Tango, F.C.P. Gonc¸alves UNESP, Univ. Estadual Paulista, Brazil Purpose: Bis-acrylic resins have shown appropriate applications in Dentistry, but this kind of polymer-based provisional restorative materials are weak and, even well-made restorations can fail due to fractures in prosthodontics devices. The proposal of this research was to study the flexural strength of a bis-acrylic resin (Structur 2 SC, Voco), when an experimental nylon fiber is added to its structure.
Methods and materials: Bar shaped specimens were prepared (20 mm × 3 mm × 10 mm) and groups were formed as follows (n = 10): S-bis-acrylic resin (control), SN-bis-acrylic resin with nylon mesh; SNS-bis-acrylic resin with a nylon and silica, three other groups were formed similarly to the above groups but with additional thermal cycling (SC, SNC and SNSC). Nylon fibers were incorporated into the median region of specimens. After finishing, polishing and or thermal cycling, the specimens were tested in a flexural strength by three points bending test using a universal testing machine EMIC. Results: Data in MegaPascal (MPa) were compiled and submitted to ANOVA and Tukey’s tests (5%). Means and standard deviation were: S-60.93/1.34a; SC-54.39/1.70b; SN-72.9/1.68c; SNC-64.56/1.66d; SNS-91.10/0.79e; SNSC-84.30/1.43f. Different letters show statistical difference between groups. Conclusion: It was concluded that the addition of nylon fibers improved the flexural strength of bis-acrylic resins, but thermal cycling resulted in a decrease of these values for all groups. Keywords: Bis-acrylic resin; Flexural strength; Nylon fiber http://dx.doi.org/10.1016/j.dental.2014.08.124 124 Preparation and characterization of radio-opaque E-glass fiber reinforced composite J. He 1,2,3,∗ , L.V. Lassila 1,2 , P.K. Vallittu 1,2 1
Department of Biomaterials Science, Institute of Dentistry and Biocity Turku Biomaterials Research Program, University of Turku, Turku, Finland 2 Turku Clinical Biomaterials Centre – TCBC, University of Turku, Turku, Finland 3 College of Materials Science and Engineering, South China University of Technology, Guangzhou, China Purpose: The purpose of this research is to endow E-glass fiber reinforced composite (FRC) with radio-opacity with a synthesized iodine containing methacrylate. The double bond conversion (DC), flexural strength (FS) and modulus (FM), and radio-opacity of prepared FRC were evaluated and compared with the FRC without iodine containing methacrylate. Methods and materials: Iodine containing methacrylate 2-hydroxy-3-methacryloyl-oxypropyl(2,3,5-triiodobenzoate) (IMB) was synthesized in our lab and mixed with Bi-GMA at the mass ratio of (IMB:Bis-GMA) 10:90, 20:80,40:60, and 60:40 as resin matrix for FRC. 0.7 wt.% of CQ and DMAEMA were added as photoinitiation system. Unidirectional E-glass fiber R338-2400 was purchased from Ahlstrom Co., Finland. DC was determined by FT-IR analysis. The FS and FM were measured using three-point set up. Radiograph was taken to determine the radio-opacity of the FRC. Results: The values of DC, FS, and FM were summarized in Table 1. As shown in Table 1, when mass content of IBM in resin matrix was 10% and 20%, the DCs of corresponding FRCs were nearly the same as the DC of control FRC (p > 0.05), when
(p > 0.05). Regarding the qualitative analysis, there were a larger number of cracks in the final specimens of MTA Fillapex and loss of structure in the specimens of all sealers. The spectrometry results showed significantly (p < 0.05) greater release of Ca2+ , K+ and Na+ ions from MTA Fillapex and Zn2+ ions from Endofill. Conclusion: AH Plus and Endofill fulfilled the ANSI/ADA recommendations for solubility when the percentage of mass variation was analyzed and presented lower volumetric variation and ion release. It may be suggested that CT and atomic absorption spectrometry are important research tools to complement the solubility test.
e61
Results: The addition of rhodamine at 0.05% (426.20 ± 1.30) and 0.01% (422.00 ± 7.58) concentrations did not alter the setting time of AH Plus pure (468.00 ± 10.20), being similar to each other (p > 0.05). For the flow, no statistically significant difference (p > 0.05) was observed between AH Plus pure (38.51 ± 0.36) and added with the fluorescent agent at 0.1% (43.15 ± 0.70), 0.05% (40.39 ± 1.42) and 0.01% (38.32 ± 0.47). For the solubility test, only the 0.01% concentration (0.49 ± 0.06) was statistically similar (p > 0.05) to AH Plus pure (0.21 ± 0.10). Regarding the addition of fluorescein, the 0.01% concentration presented statistically similar (p > 0.05) setting time (480.84 ± 17.44) and solubility (0.25 ± 0.10) to those
Keywords: Solubility; MicroCT; Root canal sealers
http://dx.doi.org/10.1016/j.dental.2014.08.121 121 Influence of fluorescent agents on physicochemical properties of resin sealer F.J.A. Rached-Júnior ∗ , M.A.L. Ferraz, L.M. Macedo, C.S. Miranda, Y.T.C. Silva-Sousa University of Ribeirão Preto, School of Dentistry, Ribeirão Preto, SP, Brazil Purpose: The objective of this study was to assess whether the addition of the fluorescent agents rhodamine and fluorescein, used in confocal laser microscopy, alters the physicochemical properties of AH Plus epoxy resin-based sealer. Methods and materials: Samples of AH Plus epoxy resinbased sealer, pure and with addition of the fluorescent agents rhodamine and fluorescein at 0.1%, 0.05% and 0.01% concentrations, were prepared for evaluation of the setting time, flow and solubility, in accordance with ANSI/ADA Specification 57. To determine the setting time, molds (10 mm diameter and 2 mm thick) were filled with cement. After 150 s, the cements were tested with a Gilmore needle (100 g), every 60 s until no more indentations on the surface were found. For the flow test, 0.5 mL of cement was placed on a glass plate and, after 180 s, another plate and additional weight was placed over the sealer (total 120 g). After 10 min, the larger and smaller diameter of the formed discs was measured. For the solubility test, 10 specimens (1.5 mm thick and 7.75 mm diameter) were prepared for each group. After weighing two specimens at a time, they were immersed in 7.5 mL of distilled water for 7 days and weighed again, to determine the percentage of mass loss. Data were subjected to ANOVA and Tukey’s test (a = 5%).
of AH Plus pure (468 ± 10.20 and 0.21 ± 0.10, respectively). Regarding the flow, the addition of 0.05% (35.50 ± 1.09) and 0.01% (36.99 ± 1.48) concentrations resulted in similar results (p > 0.05) to those of AH Plus (38.36 ± 0.36). Conclusion: It may be concluded that the addition of the fluorescent agents rhodamine and fluorescein at 0.01% concentration did not alter the setting time, flow and solubility of AH Plus epoxy resin-based sealer. Keywords: Endodontics; Physicochemical properties; Fluorescent agents http://dx.doi.org/10.1016/j.dental.2014.08.122 122 Physicochemical properties of epoxy resin-based root canal sealers G.B. Leoni 1,∗ , J.F.M. Chaves 1 , B.M. Crozeta 1 , V.L.C. Araújo 1 , R.P.F. Rosa 1 , F.J.A. Rached-Junior 2 , Y.T.C. Silva-Sousa 2 , M.D. Sousa-Neto 1 1 2
University of Sao Paulo, Brazil University of Ribeirao Preto, Brazil
Purpose: The aim of this study was to evaluate the following physicochemical properties of the epoxy resin-based root canal sealers MM Seal and AH Plus, according to the ANSI/ADA standards: setting time (ST), flow (F), radiopacity (RP), dimensional change (DC) and solubility (SB). Methods and materials: For analysis of ST, the sealers were placed inside cylindrical stainless steel molds and tested with a Gilmore needle (100 g). For F, the sealers were placed on a glass plate and, 180 s after start of mixing, another plate with 120 g mass was pressed against the material. Diameters were
e62
d e n t a l m a t e r i a l s 3 0 S ( 2 0 1 4 ) e1–e180
Table 1 – Physical properties of the sealers (mean ± standard deviation). MM Seal Setting time (min) Flow (mm) Radiopacity (mm Al) Dimensional change (%) Solubility (%)
72.60 52.75 2.32 8.47 0.94
± ± ± ± ±
AH Plus 1
4.39 0.601 0.901 2.411 0.171
463.6 36.42 7.52 0.06 0.41
± ± ± ± ±
13.222 0.402 1.592 0.122 0.212
Lowercase letters indicate statistically significant difference in columns (p < 0.05).
recorded 10 minutes after the start of mixing. For RP, the sealers were placed inside circular Teflon molds, radiographed and the radiographic density (mm Al) was measured using Digora software. For DC, the sealers were placed inside cylindrical molds, measured for length, immersed in distilled water for 30 days, dried and measured again to determine the percentage of the dimensional alterations. For SB, circular molds were filled with the sealers, weighed, immersed in water, reweighed after 7 days, and the liquids were analyzed by atomic absorption spectrometry. Data were analyzed statistically by ANOVA and Tukey’s test (a = 5%). Results: The ST means for MM Seal and AH Plus were 72.60 ± 4.39 and 463.6 ± 13.22, respectively. The F means for MM Seal and AH Plus were 52.75 ± 0.60 and 36.42 ± 0.40, respectively. For RP, AH Plus presented higher mean value (7.52 ± 1.59) than MM Seal (2.32 ± 0.90). For DC (MM Seal 8.47 ± 2.41; AH Plus 0.06 ± 0.12) and SB (MM Seal 0.94 ± 0.17; AH Plus 0.41 ± 0.21), AH Plus presented better results. There was statistically significant difference between the sealers for the physicochemical properties ST, F, RP, DC and SB, with lower F, DC and SB values for AH Plus (p < 0.05). The results of the atomic absorption spectrometry showed greater release of Ca2+ , K+ , Na+ , Ni+ and Zn2+ ions from MM Seal (p < 0.05) (Table 1). Conclusion: Only AH Plus fulfilled all ANSI/ADA recommendations relative to the physicochemical properties evaluated in this study. Keywords: Epoxy resin-based sealer; Root canal sealers; Physical properties http://dx.doi.org/10.1016/j.dental.2014.08.123 123 Flexural strength of bis-acrylic resin reinforced with experimental nylon fiber T.J.A. Paes-Junior ∗ , H. Yamada, C.S. Almeida, R.N. Tango, F.C.P. Gonc¸alves UNESP, Univ. Estadual Paulista, Brazil Purpose: Bis-acrylic resins have shown appropriate applications in Dentistry, but this kind of polymer-based provisional restorative materials are weak and, even well-made restorations can fail due to fractures in prosthodontics devices. The proposal of this research was to study the flexural strength of a bis-acrylic resin (Structur 2 SC, Voco), when an experimental nylon fiber is added to its structure.
Methods and materials: Bar shaped specimens were prepared (20 mm × 3 mm × 10 mm) and groups were formed as follows (n = 10): S-bis-acrylic resin (control), SN-bis-acrylic resin with nylon mesh; SNS-bis-acrylic resin with a nylon and silica, three other groups were formed similarly to the above groups but with additional thermal cycling (SC, SNC and SNSC). Nylon fibers were incorporated into the median region of specimens. After finishing, polishing and or thermal cycling, the specimens were tested in a flexural strength by three points bending test using a universal testing machine EMIC. Results: Data in MegaPascal (MPa) were compiled and submitted to ANOVA and Tukey’s tests (5%). Means and standard deviation were: S-60.93/1.34a; SC-54.39/1.70b; SN-72.9/1.68c; SNC-64.56/1.66d; SNS-91.10/0.79e; SNSC-84.30/1.43f. Different letters show statistical difference between groups. Conclusion: It was concluded that the addition of nylon fibers improved the flexural strength of bis-acrylic resins, but thermal cycling resulted in a decrease of these values for all groups. Keywords: Bis-acrylic resin; Flexural strength; Nylon fiber http://dx.doi.org/10.1016/j.dental.2014.08.124 124 Preparation and characterization of radio-opaque E-glass fiber reinforced composite J. He 1,2,3,∗ , L.V. Lassila 1,2 , P.K. Vallittu 1,2 1
Department of Biomaterials Science, Institute of Dentistry and Biocity Turku Biomaterials Research Program, University of Turku, Turku, Finland 2 Turku Clinical Biomaterials Centre – TCBC, University of Turku, Turku, Finland 3 College of Materials Science and Engineering, South China University of Technology, Guangzhou, China Purpose: The purpose of this research is to endow E-glass fiber reinforced composite (FRC) with radio-opacity with a synthesized iodine containing methacrylate. The double bond conversion (DC), flexural strength (FS) and modulus (FM), and radio-opacity of prepared FRC were evaluated and compared with the FRC without iodine containing methacrylate. Methods and materials: Iodine containing methacrylate 2-hydroxy-3-methacryloyl-oxypropyl(2,3,5-triiodobenzoate) (IMB) was synthesized in our lab and mixed with Bi-GMA at the mass ratio of (IMB:Bis-GMA) 10:90, 20:80,40:60, and 60:40 as resin matrix for FRC. 0.7 wt.% of CQ and DMAEMA were added as photoinitiation system. Unidirectional E-glass fiber R338-2400 was purchased from Ahlstrom Co., Finland. DC was determined by FT-IR analysis. The FS and FM were measured using three-point set up. Radiograph was taken to determine the radio-opacity of the FRC. Results: The values of DC, FS, and FM were summarized in Table 1. As shown in Table 1, when mass content of IBM in resin matrix was 10% and 20%, the DCs of corresponding FRCs were nearly the same as the DC of control FRC (p > 0.05), when