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Properties of a model composite with submicron glass fillers
e49
d e n t a l m a t e r i a l s 2 7 S ( 2 0 1 1 ) e1–e84
and LEDs (UltraBlueIS and UltraLume5). With a Power meter and a spectrometer (USB 2000) the total and emitted irradiance were measured. The absorption curve of the PI was evaluated by a spectrophotometer (Varian Cary 5G). The DC was measured by FTIR (n = 4). Rectangular specimens (7 mm × 2 mm × 1 mm, n = 10) were made for the FS and FM tests in a universal testing machine (Instron, 0.5 mm/min). Data were submitted to ANOVA and Tukey test at a pre-set alpha of 0.05. Results: The CQ has the light absorption narrowed on the light region of the visible light with the maximum absorption at 468 nm, while PPD initiates the curve on the UV region with maximum absorption at 398 nm terminating in the visible light. For the DC, the combination UltraLume/CQ showed the highest values (74.1%), while the combination XL2500/PPD promoted the lower values (61.0%). For the FS, XL500 and UltraBlueIS showed the highest values for the resins with the association CQ/PPD (96.0 and 91.1 MPa) or PPD only (90.1 and 89.3 MPa). However, for the FM, there were not statistical differences among the tested groups. Conclusions: The photoinitiator system and light curing unit influenced the physical and mechanical properties of the experimental resins. Generally, PPD showed a good potential to initiate the polymerization reaction. doi:10.1016/j.dental.2011.08.515 113 Influence of bleaching on color, opacity and fluorescence of composites C.R.G. Torres ∗ , C.F. Ribeiro, E. Bresciani, A.B. Borges São Paulo State University – UNESP, São José dos Campos, São Paulo, Brazil Objectives: The aim of the present study was to evaluate the effect of 20 and 35% hydrogen peroxide bleaching gels on color, opacity and fluorescence of composite resins. Materials and methods: Seven composite resin brands were tested1,2,3,4,5,6,7 and 30 specimens (3 mm in diameter and 2 mm thick) of each material were fabricated, totalizing 210 specimens. Specimens of each tested material were divided into three subgroups (n = 10) according to tested bleaching therapy, 20 and 35% hydrogen peroxide gels8 and the control group. The baseline color, opacity and fluorescence were assessed by spectrophotometry9 using the Lab system. Four 30-min bleaching gel applications, 2 h in total, were performed. The control group did not receive bleaching treatment, being stored in deionized water. Final assessments were performed and data analyzed by two-way ANOVA and Tukey’s tests, at 5% significance level.
Results: Color changes were statistically influenced by different tested bleaching therapies (p < 0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p < 0.0001) and bleaching therapy (p = 0.0016). No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey’s test. The greatest fluorescence alteration was detected on Z350. Conclusions: It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables and significant fluorescence changes were material and bleaching therapy dependent, regardless the gel concentration. doi:10.1016/j.dental.2011.08.516 114 Properties of a model composite with submicron glass fillers L.L. Valente ∗ , S.L. Peralta, R.R. Moraes Federal University of Pelotas, Brazil Objectives: This study evaluated the incorporation of a submicron inorganic filler matrix with narrow grain size distribution on selected properties of a model dimethacrylatebased dental composite. Materials and methods: A model comonomer based on BisGMA, Bis-EMA, UDMA e TEGDMA was loaded with a 70% mass fraction of the submicron inorganic system. A microhybrid glass filler system was tested as a reference. Degree of C C conversion (DC) was assessed using infrared spectroscopy. Flexural strength (FS) and flexural modulus (Ef) were measured on three-point bending mode. Knoop hardness number (KHN) was measured using a microindenter. Data were separately analyzed using t-tests (P < 0.05). Results: Means (standard deviations) for all evaluations are shown in the Table. Filler system
DC, %
Microhybrid Submicron
66 (7) a 60 (4) b
FS, MPa
104 (9) a 78 (5) b
2 3 4 5 6 7 8 9
Admira, Voco. Amaris, Voco. Estelite Sigma,Tokuyama. Esthet X, Dentsply. Venus, Heraeus Kulzer. Filtek Z350, 3M ESPE. Grandio SO, Voco. Whiteness HP, FGM. CM-2600d, Konica Minolta.
KHN, kgf mm−2
5.4 (0.8) a 4.1 (1.0) b
45 (6) a 45 (5) a
Different letters in the same column indicate significant differences.
Conclusions: Except for KHN, all properties were significantly lower for the composite with submicron glass particles. Efforts to improve the mechanical strength of the material are necessary. doi:10.1016/j.dental.2011.08.517
1
Ef, GPa
d e n t a l m a t e r i a l s 2 7 S ( 2 0 1 1 ) e1–e84
and LEDs (UltraBlueIS and UltraLume5). With a Power meter and a spectrometer (USB 2000) the total and emitted irradiance were measured. The absorption curve of the PI was evaluated by a spectrophotometer (Varian Cary 5G). The DC was measured by FTIR (n = 4). Rectangular specimens (7 mm × 2 mm × 1 mm, n = 10) were made for the FS and FM tests in a universal testing machine (Instron, 0.5 mm/min). Data were submitted to ANOVA and Tukey test at a pre-set alpha of 0.05. Results: The CQ has the light absorption narrowed on the light region of the visible light with the maximum absorption at 468 nm, while PPD initiates the curve on the UV region with maximum absorption at 398 nm terminating in the visible light. For the DC, the combination UltraLume/CQ showed the highest values (74.1%), while the combination XL2500/PPD promoted the lower values (61.0%). For the FS, XL500 and UltraBlueIS showed the highest values for the resins with the association CQ/PPD (96.0 and 91.1 MPa) or PPD only (90.1 and 89.3 MPa). However, for the FM, there were not statistical differences among the tested groups. Conclusions: The photoinitiator system and light curing unit influenced the physical and mechanical properties of the experimental resins. Generally, PPD showed a good potential to initiate the polymerization reaction. doi:10.1016/j.dental.2011.08.515 113 Influence of bleaching on color, opacity and fluorescence of composites C.R.G. Torres ∗ , C.F. Ribeiro, E. Bresciani, A.B. Borges São Paulo State University – UNESP, São José dos Campos, São Paulo, Brazil Objectives: The aim of the present study was to evaluate the effect of 20 and 35% hydrogen peroxide bleaching gels on color, opacity and fluorescence of composite resins. Materials and methods: Seven composite resin brands were tested1,2,3,4,5,6,7 and 30 specimens (3 mm in diameter and 2 mm thick) of each material were fabricated, totalizing 210 specimens. Specimens of each tested material were divided into three subgroups (n = 10) according to tested bleaching therapy, 20 and 35% hydrogen peroxide gels8 and the control group. The baseline color, opacity and fluorescence were assessed by spectrophotometry9 using the Lab system. Four 30-min bleaching gel applications, 2 h in total, were performed. The control group did not receive bleaching treatment, being stored in deionized water. Final assessments were performed and data analyzed by two-way ANOVA and Tukey’s tests, at 5% significance level.
Results: Color changes were statistically influenced by different tested bleaching therapies (p < 0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p < 0.0001) and bleaching therapy (p = 0.0016). No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey’s test. The greatest fluorescence alteration was detected on Z350. Conclusions: It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables and significant fluorescence changes were material and bleaching therapy dependent, regardless the gel concentration. doi:10.1016/j.dental.2011.08.516 114 Properties of a model composite with submicron glass fillers L.L. Valente ∗ , S.L. Peralta, R.R. Moraes Federal University of Pelotas, Brazil Objectives: This study evaluated the incorporation of a submicron inorganic filler matrix with narrow grain size distribution on selected properties of a model dimethacrylatebased dental composite. Materials and methods: A model comonomer based on BisGMA, Bis-EMA, UDMA e TEGDMA was loaded with a 70% mass fraction of the submicron inorganic system. A microhybrid glass filler system was tested as a reference. Degree of C C conversion (DC) was assessed using infrared spectroscopy. Flexural strength (FS) and flexural modulus (Ef) were measured on three-point bending mode. Knoop hardness number (KHN) was measured using a microindenter. Data were separately analyzed using t-tests (P < 0.05). Results: Means (standard deviations) for all evaluations are shown in the Table. Filler system
DC, %
Microhybrid Submicron
66 (7) a 60 (4) b
FS, MPa
104 (9) a 78 (5) b
2 3 4 5 6 7 8 9
Admira, Voco. Amaris, Voco. Estelite Sigma,Tokuyama. Esthet X, Dentsply. Venus, Heraeus Kulzer. Filtek Z350, 3M ESPE. Grandio SO, Voco. Whiteness HP, FGM. CM-2600d, Konica Minolta.
KHN, kgf mm−2
5.4 (0.8) a 4.1 (1.0) b
45 (6) a 45 (5) a
Different letters in the same column indicate significant differences.
Conclusions: Except for KHN, all properties were significantly lower for the composite with submicron glass particles. Efforts to improve the mechanical strength of the material are necessary. doi:10.1016/j.dental.2011.08.517
1
Ef, GPa