Statement of problem. Clinicians have used disinfection materials to remove surface contaminants during cavity preparation. It has been postulated that disinfection materials may negatively affect shear bond strength of restorative materials. If so, large numbers of restorations may be predestined for early failure with the use of a disinfection protocol.Purpose. To determine whether there is a difference in the bond strength between dentin and composite resin with a 3-step disinfection technique compared to a conventional bonding technique without the additional disinfection protocol.Material and Methods. Sixty human molar teeth were sectioned parallel to the occlusal surface to expose mid-coronal dentin and mounted parallel to a bond shearing device on a universal testing machine (Instron) and randomly divided into 2 groups. In Group I (n=30), specimens were treated with chlorhexidine, tubulicid red, and sodium hypochlorite before dentin bonding, following the manufacturer's instructions for All Bond 2. In Group II (n=30), specimens were treated only with the bonding protocol of All Bond 2. To ensure a uniform bond surface area, core paste was syringed into a cylindrical mold (diameter 2.38mm, height 2.00mm) that was in contact with the dentin bonding surface of each specimen, and allowed to set under constant force. All specimens were subjected to fracture by shear loading in a universal testing machine (Instron) at a uniform crosshead speed of 0.02 inch per minute and expressed as MPa. Statistical analysis, using nonpaired student's t-test, was performed. Results. A statistically-significant higher shear bond strength was found for the 3-step disinfection group (mean shear bond strength, 25.3; STD, 4.6) compared to the conventional bonding group (mean shear bond strength, 20.5, STD, 3.4) (PConclusions. The 3-step disinfection technique group showed a significantly stronger dentin shear bond strength compared to the conventional bonding technique without disinfection.

Orientador: Marco Antonio Bottino / Banca: Luiz Felipe Valandro / Banca: Marcelo Giannini / Banca: Marcela Rocha de Oliveira Carrilho / Banca: Maximiliano Piero Neisser / Resumo: Esse estudo avaliou a performance de dois adesivos com condicionamento ácido prévio (All- Bond 2 e One-step Plus - Bisco) e dois sistemas adesivos autocondicionantes (Clearfil SE Bond- Kuraray e Xeno III- Dentsply) quanto à resistência de união à dentina coronária e do canal radicular, penetração do adesivo na dentina desmineralizada e influência sobre o grau de conversão do cimento resinoso. Também foi determinada, com mecânica da fratura, a tenacidade da interface pino/cimento/dentina formada com o adesivo All-Bond 2. O canal radicular de 80 dentes humanos anteriores superiores foi instrumentado e, em seguida, preparado com brocas do sistema de pinos FRC Postec (Ivoclar). A dentina foi tratada com um dos sistemas adesivos e o pino foi cimentado com cimento Duo-link (Bisco). Oito grupos foram formados de acordo com o sistema adesivo e o tempo de armazenagem em saliva artificial (7 d ou 4 m). Seis secções transversais (~1,0 mm) foram obtidas das regiões compreendidas entre 4 mm acima da JEC até 4mm do ápice radicular, isto é, dentina coronária e do canal radicular. Três destas seis secções foram submetidas ao teste de pushout em máquina de ensaio universal Instron (1 mm/min, 50 Kgf). Nas secções restantes foram avaliados o grau de conversão do cimento e a penetração do adesivo na dentina com μ-Espectroscopia Raman. As amostras de tenacidade consistiram de dois hemi-discos de resina reforçada por fibra (pino) cimentados a duas fatias de dentina da câmara pulpar, formando um sanduíche (espécime Brazil nut). Os resultados do teste Anova 3-fatores de medida repetida (p<0.05) indicam que, apenas, a "região" exerceu efeito significante sobre a resistência de união (MPa). Na porção coronária (4,20 MPa) a resistência foi maior que nas regiões média (3,45 MPa) e apical (3,26 MPa) (Tukey, 5%). A tenacidade de fratura da interface cimento-dentina foi maior... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study evaluated the performance of two etch-and-rinse (All-Bond 2 andOne-step Plus- Bisco) and two self-etch adhesive systems (Clearfil SE Bond- Kuraray and XenoIII-Dentsply) concerning their bonding durability to coronal and root canal dentin, infiltration onto dentin and influence on the degree of cure of a dual-cure cement. It was also determined the interfacial fracture toughness of the post/cement/dentin interface forme with All-Bond 2. The root canals of 80 human incisors and canines were instrumented and prepared with burs (FRC Postec System, Ivoclar). Dentin was treated with one of the four adhesives and FRC Postec posts (Ivoclar) were cemented to the root canal with Duo-link dual-cure resin cement (Bisco). Eight groups were formed according to the adhesive system employed and the aging time in water (7 or 4 m). Six transverse sections (~1.0 mm) were cut from 4 mm above the CEJ up to 4 mm short of the root canal apex, comprising coronal and root canal dentin. Three out of the six sections were submitted to push-out testing in an Instron machine (1 mm/min, 50 Kgf). The degree of conversion of the cement and the infiltration of the adhesive were evaluated in the remaining sections through Raman μ-Spectroscopy. The fracture toughness specimens were made out of two half disks of fiber-reinforced composite (post) cemented to dentin pieces, forming the Brazil nut specimen. The analisys obtained with the 3-way Anova of repeated measures test (p<0.05) showed that only the "region" had statistically significant effects on the bond strengths (MPa). Comparison of the means achieved in each region (Tukey, p < 0.05) revealed that the coronal portion (4.20 MPa) was higher than the cervical (3.45 MPa) and middle portions (3.26 MPa) of the root, which were not statistically different. The interfacial fracture toughness was higher for the cement-dentin interface than... (Complete abstract click electronic access below) / Doutor

Made available in DSpace on 2014-06-11T19:35:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-05-08Bitstream added on 2014-06-13T20:06:14Z : No. of bitstreams: 1 melo_rm_dr_sjc.pdf: 3484297 bytes, checksum: 204bf95c70038c23b08cc2d82b5974c4 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Esse estudo avaliou a performance de dois adesivos com condicionamento ácido prévio (All- Bond 2 e One-step Plus - Bisco) e dois sistemas adesivos autocondicionantes (Clearfil SE Bond- Kuraray e Xeno III- Dentsply) quanto à resistência de união à dentina coronária e do canal radicular, penetração do adesivo na dentina desmineralizada e influência sobre o grau de conversão do cimento resinoso. Também foi determinada, com mecânica da fratura, a tenacidade da interface pino/cimento/dentina formada com o adesivo All-Bond 2. O canal radicular de 80 dentes humanos anteriores superiores foi instrumentado e, em seguida, preparado com brocas do sistema de pinos FRC Postec (Ivoclar). A dentina foi tratada com um dos sistemas adesivos e o pino foi cimentado com cimento Duo-link (Bisco). Oito grupos foram formados de acordo com o sistema adesivo e o tempo de armazenagem em saliva artificial (7 d ou 4 m). Seis secções transversais (~1,0 mm) foram obtidas das regiões compreendidas entre 4 mm acima da JEC até 4mm do ápice radicular, isto é, dentina coronária e do canal radicular. Três destas seis secções foram submetidas ao teste de pushout em máquina de ensaio universal Instron (1 mm/min, 50 Kgf). Nas secções restantes foram avaliados o grau de conversão do cimento e a penetração do adesivo na dentina com μ-Espectroscopia Raman. As amostras de tenacidade consistiram de dois hemi-discos de resina reforçada por fibra (pino) cimentados a duas fatias de dentina da câmara pulpar, formando um sanduíche (espécime Brazil nut). Os resultados do teste Anova 3-fatores de medida repetida (p<0.05) indicam que, apenas, a “região” exerceu efeito significante sobre a resistência de união (MPa). Na porção coronária (4,20 MPa) a resistência foi maior que nas regiões média (3,45 MPa) e apical (3,26 MPa) (Tukey, 5%). A tenacidade de fratura da interface cimento-dentina foi maior... / This study evaluated the performance of two etch-and-rinse (All-Bond 2 andOne-step Plus- Bisco) and two self-etch adhesive systems (Clearfil SE Bond- Kuraray and XenoIII-Dentsply) concerning their bonding durability to coronal and root canal dentin, infiltration onto dentin and influence on the degree of cure of a dual-cure cement. It was also determined the interfacial fracture toughness of the post/cement/dentin interface forme with All-Bond 2. The root canals of 80 human incisors and canines were instrumented and prepared with burs (FRC Postec System, Ivoclar). Dentin was treated with one of the four adhesives and FRC Postec posts (Ivoclar) were cemented to the root canal with Duo-link dual-cure resin cement (Bisco). Eight groups were formed according to the adhesive system employed and the aging time in water (7 or 4 m). Six transverse sections (~1.0 mm) were cut from 4 mm above the CEJ up to 4 mm short of the root canal apex, comprising coronal and root canal dentin. Three out of the six sections were submitted to push-out testing in an Instron machine (1 mm/min, 50 Kgf). The degree of conversion of the cement and the infiltration of the adhesive were evaluated in the remaining sections through Raman μ-Spectroscopy. The fracture toughness specimens were made out of two half disks of fiber–reinforced composite (post) cemented to dentin pieces, forming the Brazil nut specimen. The analisys obtained with the 3-way Anova of repeated measures test (p<0.05) showed that only the “region” had statistically significant effects on the bond strengths (MPa). Comparison of the means achieved in each region (Tukey, p < 0.05) revealed that the coronal portion (4.20 MPa) was higher than the cervical (3.45 MPa) and middle portions (3.26 MPa) of the root, which were not statistically different. The interfacial fracture toughness was higher for the cement-dentin interface than... (Complete abstract click electronic access below)