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Bond strength durability of resin cements to Y-TZP ceramic
d e n t a l m a t e r i a l s 2 6 ( 2 0 1 0 ) e125–e157
Ortholux LED Curing Light (3M Unitek) was used to cure the adhesive with a 5-s curing time interval on the mesial and distal sides of each bracket The bonded teeth were stored overnight in 37 ◦ C water. Bond strength was tested in a shearpeel mode or tensile mode at a crosshead speed of 0.20 in./min using a MTS QTest/5 Universal Test Machine (MTS Systems Corporation) until failure was observed. The maximum force (in lb) was recorded. Bond strength was converted to MPa by dividing the force by the bracket base area. Results: Brackets
Untreated Rocatec treated
Shear peel bond strength
Tensile bond strength
lb/bracket
MPa
lb/bracket
MPa
40.7 57.2
17.1 24.0
13.5 16.7
5.7 7.0
Rocatec treated brackets provided increased shear peel and tensile bond strengths compared to untreated brackets. Analysis of Variance showed that both shear peel and tensile bond strengths of Rocatec treated brackets were statistically different from those of untreated brackets (p = 0.000 for shear peel bond strength and p = 0.003 for tensile bond strength). Conclusions: Rocatec treatment of bracket bases provided enhanced shear peel and tensile bond strengths on uncut bovine enamel. doi:10.1016/j.dental.2009.11.146
polycrystalline tetragonal zirconia ceramic (YTZP) considering 3 factors (cement in 4 levels [Panavia F2.0, Variolink II, Relyx U100, Maxcem]; surface treatment in 2 levels [cleaning with alcohol, silicatization + silanization = SS]; storage condition in 2 levels (test in 24 h, aging]) (factorial 4 × 2 × 2 = 16 groups). Materials and Methods: 192 specimens of YTZP ceramic (InCeram YZ) were manufactured and allocated in 16 groups (n = 12), according to study factors. Cements were applied in a bipartite cylindrical matrix (Ø = 3 mm) after surface treatments. Half of specimens were submitted to shear test after 24 h, while the other half was tested after aging (TC) (90 days in H2 O 37 ◦ C and thermocycling [12,000 cycles, 5–55 ◦ C]). Bond strength data (n = 12) were submitted to ANOVA 3-factors and Tukey’s test. Results: Independent of the cement type, when surface was cleaned with alcohol (control groups) (0–5.9 MPa), bond strength was significantly lower, compared to respective groups submitted to SS (7.6–35.6 MPa). Besides, in control groups, specimens suffered spontaneous failure (0 MPa) during TC (30–100%) SS enhanced significantly the bond strength for all cements. However, Maxcem cement showed significant reduction after TC, even after silicatization condition. Conclusions: Physico-chemical activation of YTZP seems to be essential to create high and stable adhesion of both conventional and self-etch adhesives when restorations lack mechanical retention. Yet the results may vary depending on the cement type.
68 doi:10.1016/j.dental.2009.11.147 Bond strength durability of resin cements to Y-TZP ceramic L.F. Valandro a,b,∗ , S.P. Pestana a , D.C. Barca a , L.G. May a,b , M. Özcan c , M.A. Bottino a a
São Paulo State University-UNESP, Brazil Federal University of Santa Maria, Brazil c University of Zürich, Switzerland b
Objectives: To evaluate the bond strength of conventional and self-adhesive resin cements to a yttrium-oxide-stabilized
e157
Ortholux LED Curing Light (3M Unitek) was used to cure the adhesive with a 5-s curing time interval on the mesial and distal sides of each bracket The bonded teeth were stored overnight in 37 ◦ C water. Bond strength was tested in a shearpeel mode or tensile mode at a crosshead speed of 0.20 in./min using a MTS QTest/5 Universal Test Machine (MTS Systems Corporation) until failure was observed. The maximum force (in lb) was recorded. Bond strength was converted to MPa by dividing the force by the bracket base area. Results: Brackets
Untreated Rocatec treated
Shear peel bond strength
Tensile bond strength
lb/bracket
MPa
lb/bracket
MPa
40.7 57.2
17.1 24.0
13.5 16.7
5.7 7.0
Rocatec treated brackets provided increased shear peel and tensile bond strengths compared to untreated brackets. Analysis of Variance showed that both shear peel and tensile bond strengths of Rocatec treated brackets were statistically different from those of untreated brackets (p = 0.000 for shear peel bond strength and p = 0.003 for tensile bond strength). Conclusions: Rocatec treatment of bracket bases provided enhanced shear peel and tensile bond strengths on uncut bovine enamel. doi:10.1016/j.dental.2009.11.146
polycrystalline tetragonal zirconia ceramic (YTZP) considering 3 factors (cement in 4 levels [Panavia F2.0, Variolink II, Relyx U100, Maxcem]; surface treatment in 2 levels [cleaning with alcohol, silicatization + silanization = SS]; storage condition in 2 levels (test in 24 h, aging]) (factorial 4 × 2 × 2 = 16 groups). Materials and Methods: 192 specimens of YTZP ceramic (InCeram YZ) were manufactured and allocated in 16 groups (n = 12), according to study factors. Cements were applied in a bipartite cylindrical matrix (Ø = 3 mm) after surface treatments. Half of specimens were submitted to shear test after 24 h, while the other half was tested after aging (TC) (90 days in H2 O 37 ◦ C and thermocycling [12,000 cycles, 5–55 ◦ C]). Bond strength data (n = 12) were submitted to ANOVA 3-factors and Tukey’s test. Results: Independent of the cement type, when surface was cleaned with alcohol (control groups) (0–5.9 MPa), bond strength was significantly lower, compared to respective groups submitted to SS (7.6–35.6 MPa). Besides, in control groups, specimens suffered spontaneous failure (0 MPa) during TC (30–100%) SS enhanced significantly the bond strength for all cements. However, Maxcem cement showed significant reduction after TC, even after silicatization condition. Conclusions: Physico-chemical activation of YTZP seems to be essential to create high and stable adhesion of both conventional and self-etch adhesives when restorations lack mechanical retention. Yet the results may vary depending on the cement type.
68 doi:10.1016/j.dental.2009.11.147 Bond strength durability of resin cements to Y-TZP ceramic L.F. Valandro a,b,∗ , S.P. Pestana a , D.C. Barca a , L.G. May a,b , M. Özcan c , M.A. Bottino a a
São Paulo State University-UNESP, Brazil Federal University of Santa Maria, Brazil c University of Zürich, Switzerland b
Objectives: To evaluate the bond strength of conventional and self-adhesive resin cements to a yttrium-oxide-stabilized
e157