The study modifies an adhesive system with hydroxyapatite nanoparticles as load, characterizing it and evaluate the effectiveness of its bond to dental structure. The middle thirds of healthy premolar tooth crowns wer...The study modifies an adhesive system with hydroxyapatite nanoparticles as load, characterizing it and evaluate the effectiveness of its bond to dental structure. The middle thirds of healthy premolar tooth crowns were obtained, and each crown was sectioned vertically, resulting in two sections. The sections were divided into ten groups (n = 15), in which resin composite restorations were simulated: (G1E and G1D) conventional adhesive system (SAC);(G2E and G2D) SAC modified with HAP;(G3E and G3D) Primer modified with HAP;(G4E and G4D) monocomponent adhesive system;(G5E and G5D) self-etching adhesive system. The specimens were submitted to the microshear test and characterization technique. There was statistically significant difference (Kruskal-Wallis) between the groups (p 0.01). G3 presented the highest bond strength to enamel (64.40 MPa, ±7.36) and dentin (39.59 MPa, ±21.46). The majority of specimens were found adhesive fractures. Bond strength to enamel and dentin of the primer modified with HAP of SAC showed higher values.展开更多
The aim of this study was to evaluate the bond strength of orthodontic brackets bonded to tooth enamel with different polymer composites after simulated clinical aging, and analyze the enamel/ bond system fracture int...The aim of this study was to evaluate the bond strength of orthodontic brackets bonded to tooth enamel with different polymer composites after simulated clinical aging, and analyze the enamel/ bond system fracture interface. 80 human premolars, were randomly divided into five groups (n = 16). G1: CO (Concise Ortodontica—3M ESPE), G2: SB (SuperBond—Ortho Source), G3: FMO (Fill Magic Ortodontico—Vigodent), G4: TXT (Transbond XT—3M ESPE) and G5: TP (Transbond Plus Self Etching Primer + Transbond Plus Color Change—3M ESPE). In all groups, the metal orthodontic bracket was bonded to the tooth enamel surface. The specimens were submitted to 3000 thermal cycling baths for 30 s, at temperatures of 5°C, 37°C and 55°C (±1°C). Afterwards they were subjected to shear testing and the results were analyzed by the Student’s-t test (p < 0.05). G1 presented the highest bond strength value, followed by G4 > G5 > G2 > G3. In all groups the majority of the fractures at the interface of the specimens were cohesive, except in G3, which presented the largest number of adhesive fractures. After clinical aging, the chemically activated material (CO) showed higher bond strength than the light activated types (FMO, TXT and TP). The self-etching adhesive system (TP) showed similar bond strength to that of conventional systems (FMO and TXT).展开更多
文摘The study modifies an adhesive system with hydroxyapatite nanoparticles as load, characterizing it and evaluate the effectiveness of its bond to dental structure. The middle thirds of healthy premolar tooth crowns were obtained, and each crown was sectioned vertically, resulting in two sections. The sections were divided into ten groups (n = 15), in which resin composite restorations were simulated: (G1E and G1D) conventional adhesive system (SAC);(G2E and G2D) SAC modified with HAP;(G3E and G3D) Primer modified with HAP;(G4E and G4D) monocomponent adhesive system;(G5E and G5D) self-etching adhesive system. The specimens were submitted to the microshear test and characterization technique. There was statistically significant difference (Kruskal-Wallis) between the groups (p 0.01). G3 presented the highest bond strength to enamel (64.40 MPa, ±7.36) and dentin (39.59 MPa, ±21.46). The majority of specimens were found adhesive fractures. Bond strength to enamel and dentin of the primer modified with HAP of SAC showed higher values.
文摘The aim of this study was to evaluate the bond strength of orthodontic brackets bonded to tooth enamel with different polymer composites after simulated clinical aging, and analyze the enamel/ bond system fracture interface. 80 human premolars, were randomly divided into five groups (n = 16). G1: CO (Concise Ortodontica—3M ESPE), G2: SB (SuperBond—Ortho Source), G3: FMO (Fill Magic Ortodontico—Vigodent), G4: TXT (Transbond XT—3M ESPE) and G5: TP (Transbond Plus Self Etching Primer + Transbond Plus Color Change—3M ESPE). In all groups, the metal orthodontic bracket was bonded to the tooth enamel surface. The specimens were submitted to 3000 thermal cycling baths for 30 s, at temperatures of 5°C, 37°C and 55°C (±1°C). Afterwards they were subjected to shear testing and the results were analyzed by the Student’s-t test (p < 0.05). G1 presented the highest bond strength value, followed by G4 > G5 > G2 > G3. In all groups the majority of the fractures at the interface of the specimens were cohesive, except in G3, which presented the largest number of adhesive fractures. After clinical aging, the chemically activated material (CO) showed higher bond strength than the light activated types (FMO, TXT and TP). The self-etching adhesive system (TP) showed similar bond strength to that of conventional systems (FMO and TXT).
