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Effect of multiple sintering cycles on the translucency parameter of dental ceramics
e47
d e n t a l m a t e r i a l s 2 6 S ( 2 0 1 0 ) e1–e84
Disks of composite resin2 were used as substrate. Cementations were performed with a self-etch/self-adhesive resin cement3 in 5 different colors with a standardized seating force. In the control group, glycerin was used instead of cement. The specimen were measured in CIELab* system with a spectrophotometer equipped with an integrating sphere.
Table 1 – .
2
L∗2 + a∗2 + b∗2 was used to calcuThe formula E = late the differences in color between samples and the control group. Results: Thickness
0.5 mm
Surface treatment
No metal primer II [MPa]
PF (%)
[MPa]
PF (%)
Sandblasting (S) Hot etching 30 min (ST) SIE (SIE) No treatment (C)
14.98 (7.97) A 17.97 (8.57) B
0 11.11
24.49 (7.89) B 18.70 (8.13) A
0 11.11
12.25 (10.96) A 10.66 (9.89) A
30.00 31.25
19.37 (9.59) A 16.0 (10.34) A
5.16 26.66
Different capital letters indicate groups that are statistically different (p < 0.05).
1 mm
1.5 mm
Sign. total shade
Shade
Mean
SD
Sign.
Mean
SD
Sign.
Mean
SD
Sign.
Clear White Yellow Brown White Op Tot. mean
1.154 1.426 2.567 3.503 2.207 2.171
0.489 0.140 0.670 0.405 0.557 0.200
a b c d bc B
0.879 1.955 3.049 2.659 3.911 2.490
0.506 0.577 0.670 0.600 0.656 0.066
a b c c d C
0.971 1.048 1.269 1.953 3.376 1.723
0.494 0.216 0.509 0.801 0.229 0.241
a a a b c A
The Two Way ANOVA was applied, followed by the Tukey test for post hoc comparisons (p < 0.05). Conclusions: For the ceramic tested, and in relation with its thickness the color of the cement is able to influence the final color of the restoration. doi:10.1016/j.dental.2010.08.107 100 Effect of surface conditioning on bonding to zirconium-oxide ceramic A. Casucci 1 , C. Goracci 1 , F. Sedda 1 , M. Ferrari 1 1 2
Monticelli 2 , N.
Chieffi 1 , M.
University of Siena, Italy University of Huesca, Spain
Objectives: To evaluate the influence of different surface treatments and metal primer application on the microtensile bond strength of zirconia ceramic to cured resin cement. Materials and methods: Twenty-four cylinder-shaped (Ø 12 mm × 5.25 mm high) of zirconia sintered CAD/CAM blocks (Aadva Zirconia, GC, Tokyo, Japan) were randomly divided into 4 groups (n = 6), based on the surface treatment to be performed: (1) airborne particle abrasion with 125 m Al2 O3 particles (S); (2) experimental hot etching solution applied for 30 min (ST); (3) selective infiltration etching (SIE); (4) no treatment (C). Paradigm MZ100 blocks (3M ESPE) were cut into 24 cylinders of 4 mm in thickness. Half of the zirconia specimens of each group received the application of Metal Primer II. Conditioned Zirconia and composite cylinders were luted using a resin cement (G-Cem), in combination with the proprietary adhesive system. After 24 h bonded
2
Herculite XRV Ultra Dentine #A2, Kerr. Maxcem Elite #Clear, White, White Opaque, Yellow and Brown, Kerr. 3
Metal primer II
A B C D E
specimens were cut into microtensile sticks and loaded in tension until failure. Data were analyzed with two-way ANOVA and Tukey test for multiple comparisons (p < 0.05). Failure mode distribution was recorded and the interfacial morphology of debonded specimens was analyzed using a scanning electron microscope (SEM). Results: Means of bond strength are reported in Table 1. Both surface treatment and the application of Metal Primer II improved significantly bond strength values (p < 0.05). When Metal Primer II was not applied on to the zirconia surface ST treatment achieved highest bond strength values (p < 0.05). Sandblasting in combination with metal primer obtained the highest bond strength values. Premature failures were mostly recorded in the C group. Conclusions: Conditioning the high-strength ceramic surfaces with metal primer II significantly improved the zirconia bond strength with all surface treatment tested. doi:10.1016/j.dental.2010.08.108 101 Effect of multiple sintering cycles on the translucency parameter of dental ceramics P.F. Cesar 1 , C.C. Gonzaga 2 , C.F.S. Pereira 1 , M.M. Pinto 3 , H.N. Yoshimura 4 1
University of São Paulo, Brazil Positivo University, Brazil 3 UNINOVE, Brazil 4 Federal University of ABC, Brazil 2
Objectives: The objective of this study was to determine the translucency parameter (TP) of dental enamel and eight commercial veneering ceramics. The effect of multiple sintering cycles on the TP of the ceramics was also investigated. Materials and Methods: Disk specimens (n = 10, Ø 12 mm × 1 mm) were produced with the ceramics shown in Table 1. Specimens were sintered and both sides were mirror-polished. Enamel samples (1 mm-thick) were obtained from seven sound human molars. A spectrophotometer was used to measure the L*, a* and b* coordinates using two
e48
d e n t a l m a t e r i a l s 2 6 S ( 2 0 1 0 ) e1–e84
Table 1 – . Ceramic
Brand/ Number of firing cycles manufacturer 1 4 7
CO-ZR
Cerabien ZR/Noritake Duceram Kiss/Degudent E.max ceram/Ivoclar Vintage AL/Shofu Vintage Halo/Shofu VM7/Vita VM9/Vita Vintage ZR/Shofu
DK EMAX VAL VH VM7 VM9 VZR
25.4 ± 3.0a
22.8 ± 1.8a
29.5 ± 1.8a
28.1 ± 3.0a,b 25.0 ± 2.2b
17.3 ± 1.4a
20.4 ± 2.1a
19.1 ± 0.8a
27.0 ± 1.0a
27.0 ± 1.0a
26.5 ± 0.5a
18.8 ± 4.1a
19.1 ± 2.9a
18.5 ± 1.9a
17.0 ± 2.6a 25.3 ± 1.0a 16.8 ± 1.1b
19.4 ± 1.9a 27.1 ± 2.2a 27.2 ± 0.6a
17.6 ± 1.1a 24.3 ± 2.1a 25.1 ± 0.8a
21.8 ± 2.2a
*
Within the same line, values followed by the same superscript are statistically similar (p > 0.05).
standard cards as background: black (CIE L* = 24.58, a* = 0.27, b* = 2.58) and white (CIE L* = 92.95, a* = −0.78, b* = 3.57). All measurements were performed after 1, 4 and 7 firing cycles in the diffuse reflectance mode (range of between 400 and 700 nm and intervals of 10 nm). Fixed parameters were: illumination of CIE D65 (day light, 6500 K) and observer at 2◦ . TP was deter2
2
2 1/2
mined by: TP = [(L∗b − L∗w ) + (a∗b − a∗w ) + (b∗b − b∗w ) ] , where the subscripts b and w indicate the color of the background (black and white, respectively). Results were analyzed by ANOVA and Tukey’s test (˛ = 0.05). Results: The mean TP value obtained for dental enamel was 18.4 (±2.7). The values of TP as a function of the ceramic material and number of firing cycles are shown in Table 1. The results indicated that these materials can be divided in 3 distinct groups: (a) those for which the TP was not significantly affected by the multiple firing cycles and all values were similar to that of the enamel (EMAX, VH and VM7), (b) those for which TP was not significantly affected by the multiple firing cycles but the values were statistically different from that of the enamel (CO-ZR, VAL, and VM9); and (c) those for which the TP values were significantly affected by the multiple firing cycles (DK and VZR). Conclusions: Only two materials showed the same translucency level compared to dental enamel, regardless of the number of firing cycles. The effect of multiple sintering cycles on the TP values depended on the ceramic material studied.
Materials and methods: The software ANSYS version 10.0 was used to develop a FEA mesh consisting of 23,974–42,291 elements and 73,037–128,941 nodes. Two different preparation designs were tested: incisal shoulder finish line (FI) and incisal shoulder finish line with a palatal chamfer margin (FIP). The materials used in this study were pressable ceramics (IPS Empress) and resin-based luting agents (RelyX Veneer). The maximum principal stress ( max ) in all models was calculated from four interincisal load angulations: 90◦ , 120◦ , 135◦ and 160◦ to the long axis of the tooth. A 120-N, which is the maximum human bite force for maxillary anterior teeth (Kumagai et al. J Oral Rehabil 1999;26:932), was applied on the palatal surfaces of ceramic veneers at 2 mm from the incisal edges. The risks of ceramic fracture (RCF) were calculated by dividing the tensile ( max ) stress (registered in material) by its tensile strength (TS) as described in the literatures. The tensile and shear stresses in the ceramic and resin cement interfaces were analyzed to determine the risks of cement failures (RCEF). Results: Models Ceramic
FI-90 FIP-90 FI-120 FIP-120 FI-135 FIP-135 FI-160 FIP-160
Cement
max TS
RCF max TS RCEF
138.2 152.2 125.5 113.1 100.4 91.3 94.6 85.1
1.02 1.13 0.93 0.84 0.74 0.68 0.70 0.63
135.0 135.0 135.0 135.0 135.0 135.0 135.0 135.0
109.5 93.1 74.5 45.2 43.5 26.9 13.9 12.0
77.6 77.6 77.6 77.6 77.6 77.6 77.6 77.6
1.41 1.20 0.96 0.58 0.56 0.35 0.18 0.15
Maximum crown displacement (mm) 1.65 1.45 1.36 1.14 1.08 0.87 0.44 0.35
Conclusions: Interincisal load angulation has effects on the biomechanical behavior of ceramic veneers in terms of stress distribution, risks of ceramic fracture and cement failures. In most loading conditions, the shoulder finish line is susceptible to tensile stress in ceramic 10–15% higher than the other samples, suggesting higher risks of ceramic fracture. This trend, however, excludes interincisal load angulation at 90◦ . Increasing interincisal load angulation contributes to lower tensile stress in cements, suggesting lower risks of cement failures for both preparation designs. As the interincisal load angle increases, the maximum displacement of the crown decreases. doi:10.1016/j.dental.2010.08.110 103
doi:10.1016/j.dental.2010.08.109
Shade match of two ceramic systems with 3D-Master Toothguide
102
G. Corciolani, A. Vichi, M. Sedda, C. Goracci, M. Ferrari
Risks of ceramic veneer fracture under different occlusal loading conditions
University of Siena, Italy
Y. Chaiyabutr 1 , J.C. Kois 1 , V. Isvilanonda 2 1 2
Kois Center, USA University of Washington, USA
Objectives: This study used 2D finite element analysis to investigate the risks of ceramic fracture and cement failures on maxillary central incisors when different ceramic veneer preparation designs and occlusal conditions were applied.
Objectives: The purpose of this study was to test the ability of two different dental porcelains to correctly reproduce the selected color with reference to 3D-Master Toothguide by using a clinical spectrophotometer. Materials and methods: Two ceramic systems were selected for this study, Vita Omega 900 and Vita VM13. Three shades in Vita 3D-Master Toothguide were selected for each system, 2M3, 3M2 and 4M2. 30 ceramic discs, 15 mm in diameter, were fabricated with 2 different layering schemes (LS)
d e n t a l m a t e r i a l s 2 6 S ( 2 0 1 0 ) e1–e84
Disks of composite resin2 were used as substrate. Cementations were performed with a self-etch/self-adhesive resin cement3 in 5 different colors with a standardized seating force. In the control group, glycerin was used instead of cement. The specimen were measured in CIELab* system with a spectrophotometer equipped with an integrating sphere.
Table 1 – .
2
L∗2 + a∗2 + b∗2 was used to calcuThe formula E = late the differences in color between samples and the control group. Results: Thickness
0.5 mm
Surface treatment
No metal primer II [MPa]
PF (%)
[MPa]
PF (%)
Sandblasting (S) Hot etching 30 min (ST) SIE (SIE) No treatment (C)
14.98 (7.97) A 17.97 (8.57) B
0 11.11
24.49 (7.89) B 18.70 (8.13) A
0 11.11
12.25 (10.96) A 10.66 (9.89) A
30.00 31.25
19.37 (9.59) A 16.0 (10.34) A
5.16 26.66
Different capital letters indicate groups that are statistically different (p < 0.05).
1 mm
1.5 mm
Sign. total shade
Shade
Mean
SD
Sign.
Mean
SD
Sign.
Mean
SD
Sign.
Clear White Yellow Brown White Op Tot. mean
1.154 1.426 2.567 3.503 2.207 2.171
0.489 0.140 0.670 0.405 0.557 0.200
a b c d bc B
0.879 1.955 3.049 2.659 3.911 2.490
0.506 0.577 0.670 0.600 0.656 0.066
a b c c d C
0.971 1.048 1.269 1.953 3.376 1.723
0.494 0.216 0.509 0.801 0.229 0.241
a a a b c A
The Two Way ANOVA was applied, followed by the Tukey test for post hoc comparisons (p < 0.05). Conclusions: For the ceramic tested, and in relation with its thickness the color of the cement is able to influence the final color of the restoration. doi:10.1016/j.dental.2010.08.107 100 Effect of surface conditioning on bonding to zirconium-oxide ceramic A. Casucci 1 , C. Goracci 1 , F. Sedda 1 , M. Ferrari 1 1 2
Monticelli 2 , N.
Chieffi 1 , M.
University of Siena, Italy University of Huesca, Spain
Objectives: To evaluate the influence of different surface treatments and metal primer application on the microtensile bond strength of zirconia ceramic to cured resin cement. Materials and methods: Twenty-four cylinder-shaped (Ø 12 mm × 5.25 mm high) of zirconia sintered CAD/CAM blocks (Aadva Zirconia, GC, Tokyo, Japan) were randomly divided into 4 groups (n = 6), based on the surface treatment to be performed: (1) airborne particle abrasion with 125 m Al2 O3 particles (S); (2) experimental hot etching solution applied for 30 min (ST); (3) selective infiltration etching (SIE); (4) no treatment (C). Paradigm MZ100 blocks (3M ESPE) were cut into 24 cylinders of 4 mm in thickness. Half of the zirconia specimens of each group received the application of Metal Primer II. Conditioned Zirconia and composite cylinders were luted using a resin cement (G-Cem), in combination with the proprietary adhesive system. After 24 h bonded
2
Herculite XRV Ultra Dentine #A2, Kerr. Maxcem Elite #Clear, White, White Opaque, Yellow and Brown, Kerr. 3
Metal primer II
A B C D E
specimens were cut into microtensile sticks and loaded in tension until failure. Data were analyzed with two-way ANOVA and Tukey test for multiple comparisons (p < 0.05). Failure mode distribution was recorded and the interfacial morphology of debonded specimens was analyzed using a scanning electron microscope (SEM). Results: Means of bond strength are reported in Table 1. Both surface treatment and the application of Metal Primer II improved significantly bond strength values (p < 0.05). When Metal Primer II was not applied on to the zirconia surface ST treatment achieved highest bond strength values (p < 0.05). Sandblasting in combination with metal primer obtained the highest bond strength values. Premature failures were mostly recorded in the C group. Conclusions: Conditioning the high-strength ceramic surfaces with metal primer II significantly improved the zirconia bond strength with all surface treatment tested. doi:10.1016/j.dental.2010.08.108 101 Effect of multiple sintering cycles on the translucency parameter of dental ceramics P.F. Cesar 1 , C.C. Gonzaga 2 , C.F.S. Pereira 1 , M.M. Pinto 3 , H.N. Yoshimura 4 1
University of São Paulo, Brazil Positivo University, Brazil 3 UNINOVE, Brazil 4 Federal University of ABC, Brazil 2
Objectives: The objective of this study was to determine the translucency parameter (TP) of dental enamel and eight commercial veneering ceramics. The effect of multiple sintering cycles on the TP of the ceramics was also investigated. Materials and Methods: Disk specimens (n = 10, Ø 12 mm × 1 mm) were produced with the ceramics shown in Table 1. Specimens were sintered and both sides were mirror-polished. Enamel samples (1 mm-thick) were obtained from seven sound human molars. A spectrophotometer was used to measure the L*, a* and b* coordinates using two
e48
d e n t a l m a t e r i a l s 2 6 S ( 2 0 1 0 ) e1–e84
Table 1 – . Ceramic
Brand/ Number of firing cycles manufacturer 1 4 7
CO-ZR
Cerabien ZR/Noritake Duceram Kiss/Degudent E.max ceram/Ivoclar Vintage AL/Shofu Vintage Halo/Shofu VM7/Vita VM9/Vita Vintage ZR/Shofu
DK EMAX VAL VH VM7 VM9 VZR
25.4 ± 3.0a
22.8 ± 1.8a
29.5 ± 1.8a
28.1 ± 3.0a,b 25.0 ± 2.2b
17.3 ± 1.4a
20.4 ± 2.1a
19.1 ± 0.8a
27.0 ± 1.0a
27.0 ± 1.0a
26.5 ± 0.5a
18.8 ± 4.1a
19.1 ± 2.9a
18.5 ± 1.9a
17.0 ± 2.6a 25.3 ± 1.0a 16.8 ± 1.1b
19.4 ± 1.9a 27.1 ± 2.2a 27.2 ± 0.6a
17.6 ± 1.1a 24.3 ± 2.1a 25.1 ± 0.8a
21.8 ± 2.2a
*
Within the same line, values followed by the same superscript are statistically similar (p > 0.05).
standard cards as background: black (CIE L* = 24.58, a* = 0.27, b* = 2.58) and white (CIE L* = 92.95, a* = −0.78, b* = 3.57). All measurements were performed after 1, 4 and 7 firing cycles in the diffuse reflectance mode (range of between 400 and 700 nm and intervals of 10 nm). Fixed parameters were: illumination of CIE D65 (day light, 6500 K) and observer at 2◦ . TP was deter2
2
2 1/2
mined by: TP = [(L∗b − L∗w ) + (a∗b − a∗w ) + (b∗b − b∗w ) ] , where the subscripts b and w indicate the color of the background (black and white, respectively). Results were analyzed by ANOVA and Tukey’s test (˛ = 0.05). Results: The mean TP value obtained for dental enamel was 18.4 (±2.7). The values of TP as a function of the ceramic material and number of firing cycles are shown in Table 1. The results indicated that these materials can be divided in 3 distinct groups: (a) those for which the TP was not significantly affected by the multiple firing cycles and all values were similar to that of the enamel (EMAX, VH and VM7), (b) those for which TP was not significantly affected by the multiple firing cycles but the values were statistically different from that of the enamel (CO-ZR, VAL, and VM9); and (c) those for which the TP values were significantly affected by the multiple firing cycles (DK and VZR). Conclusions: Only two materials showed the same translucency level compared to dental enamel, regardless of the number of firing cycles. The effect of multiple sintering cycles on the TP values depended on the ceramic material studied.
Materials and methods: The software ANSYS version 10.0 was used to develop a FEA mesh consisting of 23,974–42,291 elements and 73,037–128,941 nodes. Two different preparation designs were tested: incisal shoulder finish line (FI) and incisal shoulder finish line with a palatal chamfer margin (FIP). The materials used in this study were pressable ceramics (IPS Empress) and resin-based luting agents (RelyX Veneer). The maximum principal stress ( max ) in all models was calculated from four interincisal load angulations: 90◦ , 120◦ , 135◦ and 160◦ to the long axis of the tooth. A 120-N, which is the maximum human bite force for maxillary anterior teeth (Kumagai et al. J Oral Rehabil 1999;26:932), was applied on the palatal surfaces of ceramic veneers at 2 mm from the incisal edges. The risks of ceramic fracture (RCF) were calculated by dividing the tensile ( max ) stress (registered in material) by its tensile strength (TS) as described in the literatures. The tensile and shear stresses in the ceramic and resin cement interfaces were analyzed to determine the risks of cement failures (RCEF). Results: Models Ceramic
FI-90 FIP-90 FI-120 FIP-120 FI-135 FIP-135 FI-160 FIP-160
Cement
max TS
RCF max TS RCEF
138.2 152.2 125.5 113.1 100.4 91.3 94.6 85.1
1.02 1.13 0.93 0.84 0.74 0.68 0.70 0.63
135.0 135.0 135.0 135.0 135.0 135.0 135.0 135.0
109.5 93.1 74.5 45.2 43.5 26.9 13.9 12.0
77.6 77.6 77.6 77.6 77.6 77.6 77.6 77.6
1.41 1.20 0.96 0.58 0.56 0.35 0.18 0.15
Maximum crown displacement (mm) 1.65 1.45 1.36 1.14 1.08 0.87 0.44 0.35
Conclusions: Interincisal load angulation has effects on the biomechanical behavior of ceramic veneers in terms of stress distribution, risks of ceramic fracture and cement failures. In most loading conditions, the shoulder finish line is susceptible to tensile stress in ceramic 10–15% higher than the other samples, suggesting higher risks of ceramic fracture. This trend, however, excludes interincisal load angulation at 90◦ . Increasing interincisal load angulation contributes to lower tensile stress in cements, suggesting lower risks of cement failures for both preparation designs. As the interincisal load angle increases, the maximum displacement of the crown decreases. doi:10.1016/j.dental.2010.08.110 103
doi:10.1016/j.dental.2010.08.109
Shade match of two ceramic systems with 3D-Master Toothguide
102
G. Corciolani, A. Vichi, M. Sedda, C. Goracci, M. Ferrari
Risks of ceramic veneer fracture under different occlusal loading conditions
University of Siena, Italy
Y. Chaiyabutr 1 , J.C. Kois 1 , V. Isvilanonda 2 1 2
Kois Center, USA University of Washington, USA
Objectives: This study used 2D finite element analysis to investigate the risks of ceramic fracture and cement failures on maxillary central incisors when different ceramic veneer preparation designs and occlusal conditions were applied.
Objectives: The purpose of this study was to test the ability of two different dental porcelains to correctly reproduce the selected color with reference to 3D-Master Toothguide by using a clinical spectrophotometer. Materials and methods: Two ceramic systems were selected for this study, Vita Omega 900 and Vita VM13. Three shades in Vita 3D-Master Toothguide were selected for each system, 2M3, 3M2 and 4M2. 30 ceramic discs, 15 mm in diameter, were fabricated with 2 different layering schemes (LS)