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Bond Strength Values (bond + strength_value)
Selected AbstractsInfluence of the mineral content and morphological pattern of artificial root caries lesion on composite resin bond strengthEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2004Anderson T. Hara Dentine substrates with different mineral contents and morphological patterns were created by submitting root slabs to the following treatments: (A) immersion in artificial saliva during the experimental period (control), (B) demineralization for 32 h to induce caries lesion (demineralized group), and (C) demineralization for 32 h followed by remineralization for 8 d (remineralized group). The slabs were longitudinally sectioned, the mineral content was determined by cross-sectional microhardness, and the bond strength of an adhesive system/composite resin was assessed using a microtensile bond strength test. The dentine morphology after the treatments as well as the failure pattern of the debonded specimens was examined by scanning electron microscopy. Statistically significant differences were found in mineral content. Morphological analysis showed marked differences between the patterns of demineralized and remineralized substrates. The bond strength mean value of the control A did not differ from the group B, but was statistically higher than the group C. Since no linear relationship was found between dentine mineral content and bond strength values, it could be suggested that the morphological pattern may be more relevant than the mineral content to explain the bond strength of composite resin to dentine. [source] Polymerization stress, flow and dentine bond strength of two resin-based root canal sealersINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2009S. F. C. Souza Abstract Aim, To compare two resin-based root canal sealers (AH Plus and dual cure Epiphany) in terms of flow, polymerization stress and bond strength to dentine. Methodology, Flow was evaluated by measuring the diameter of uncured discs of sealer (0.5 mL) after 7 min compression (20N) between two glass plates (n = 5). Polymerization stress was monitored for 60 min in 1-mm thick discs bonded to two glass rods (Ø = 5 mm) attached to a universal testing machine (n = 3). Bond strength was analyzed through micropush-out test (n = 10) and failure mode was examined with scanning electron microscope (100× and 2500×). Data were statistically analyzed using the Student's t -test (, = 0.05). Results, Polymerization stress was 0.32 ± 0.07 MPa for Epiphany self-cure, 0.65 ± 0.08 MPa for Epiphany light-cure and zero for AH Plus (P < 0.05). Flow data and bond strength values were 30.9 ± 1.1, 28.6 ± 0.7 mm and 6.3 ± 5.3, 17.8 ± 7.5 MPa for Epiphany and AH Plus, respectively (P < 0.001). Failure mode was predominantly cohesive in the sealer for both materials. Conclusions, Epiphany had higher flow and polymerization stress and lower bond strength values to dentine than AH Plus. In view of these findings it can be implied that AH Plus would provide a better seal. [source] Shear Bond Strength of Enamel Treated with Seven Carbamide Peroxide Bleaching AgentsJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 4 2004ROBERTA TARKAN. ABSTRACT Purpose:: Lower average values of bond strength of adhesive systems to enamel bleached with 10% carbamide peroxide agents have been reported, but the effects of higher concentrations of carbamide peroxide bleaching agents are still unknown. The aim of this in vitro study was to evaluate the shear bond strength of enamel treated with different concentrations of carbamide peroxide to an adhesive system after a postbleaching period of storage in artificial saliva for 15 days. Materials and Methods: Seven carbamide peroxide bleaching agents with concentrations varying from 10 to 22% were analyzed. A placebo agent was used as a control group. The agents were applied on the enamel fragments for 8 h/d for 42 days. During the remaining time, the specimens were stored in artificial saliva. After that time, the fragments were stored individually in artificial saliva for 15 days. An adhesive system was used to bond resin-based composite cylinders on the enamel surface. Shear bond strength tests were performed and the fractured surfaces of the specimens were visually examined with a stereomicroscope at ×30. Results: The analysis of variance did not show differences in shear bond strength among the treatment agents. The fractures for all treatment agents were predominantly adhesive. Conclusion: After 15 days storage in artificial saliva, different concentrations of carbamide peroxide bleaching agents and a placebo agent had the same enamel shear bond strength values. [source] Effect of Net Fiber Reinforcement Surface Treatment on Soft Denture Liner Retention and LongevityJOURNAL OF PROSTHODONTICS, Issue 4 2010MPhil, Muhanad M. Hatamleh BSc Abstract Purpose: To evaluate shear bond strength of Molloplast-B soft liner attached to different acrylic surfaces (smooth, rough, and Sticktech net fiber-reinforced interfaces) after 3000 thermal cycles. Materials and Methods: Sixty-nine specimens were fabricated by attaching Molloplast-B soft liner to acrylic bases of three interfaces (n= 23); smooth (Group 1, control), rough (Group 2), and Sticktech net fiber-reinforced interface (Group 3). The specimens underwent 3000 thermocycles (5 and 55°C) before being subject to a shear bond test at 2 mm/min crosshead speed. Debonding sites were investigated using an optical microscope at 40× magnification. Bond failures were categorized as adhesive, cohesive, or mixed. Results: Mean (SD) bond strength values (MPa) were: 0.71 (0.15); 0.63 (0.07); and 0.83 (0.12) for smooth, rough, and fiber-reinforced acrylic interfaces, respectively. The mean values were analyzed using one-way ANOVA and Bonferroni post hoc test for pairwise comparisons (p, 0.05). The net fiber-reinforced acrylic interface exhibited a statistically significantly higher bond strength value when compared to smooth and rough acrylic interfaces (P= 0.003 and P= 0.000, respectively). Modes of failure were mainly cohesive (91%), followed by mixed failures (9%). Conclusions: Molloplast-B exhibited a stronger bond to StickTech Net fiber-reinforced surfaces when compared to smooth and rough acrylic interfaces after thermocycling. This may enhance prosthesis serviceability during clinical use. [source] Tensile bond strength of a flowable composite resin to ER:YAG-laser-treated dentin,LASERS IN SURGERY AND MEDICINE, Issue 5 2005Juliana Donadio-Moura MSD Abstract Background and Objectives This in vitro study evaluated the influence of a flowable composite resin (FCR) on the tensile bond strength of resin to dentin treated with the Er:YAG Laser (L) and diamond bur (DB). Study Design/Materials and Methods Ninety dentin surfaces obtained from 45 third molars were ground and randomly divided into six groups (n,=,15): G1,DB, G2,DB+FCR, G3,L (100 mJ, 10 Hz, 37.04 J/cm2), G4,L (100 mJ, 10 Hz, 37.04 J/cm2)+FCR, G5,L (250 mJ, 2 Hz, 92.60 J/cm2), and G6,L (250 mJ, 2 Hz, 92.60 J/cm2)+FCR. After surface etching with 37% phosphoric acid and the application of an adhesive system, inverted conical specimens were prepared with a hybrid composite resin. In groups G2, G4, and G6 a FCR was placed before the hybrid composite resin. After 24 hours-storage in distilled water, the tensile test was performed in a universal testing machine (0.5 mm/minute, 500 N). Results Data were submitted to Kruskal Wallis test (P,=,0.01). The mean bond strength values (MPa±SD) were: G1,13.54 (±2.99), G2,14.67 (±2.32), G3,9.49 (±3.09), G4,14.60 (±2.76), G5,8.97 (±3.89), and G6,13.02 (±2.18). Groups G1 and G2 presented the highest bond strength values, which were statistically similar to those of G4 and G6. The groups treated with laser and without the FCR (G3 and G5) showed the lowest shear bond strength values. Conclusions FCR can increase the adhesion to dentin treated with Er:YAG laser within different parameters. © 2005 Wiley-Liss, Inc. [source] | ||||||||||