Adhesive bonding of alumina air-abraded Ag-Pd-Cu-Au alloy with 10-methacryloyloxydecyl dihydrogen phosphate.

The aim of this paper is to study changes in the Ag-Pd-Cu-Au alloy surfaces by alumina air-abrasion process and effect of those changes on the adhesive bonding characteristic. Surface roughness, surface composition and chemical state of the alumina air-abraded alloys were analyzed by a confocal laser scanning microscope, an energy dispersive X-ray spectroscopy and an X-ray photoelectron spectroscopy. The results showed that the alumina air-abrasion changed the alloy surface by mechanical roughening, alumina remain and copper oxidation. Effect of the changes in the alloy surface on the adhesive bonding characteristic was examined by using a methyl methacrylate/tri-n-butylborane derivative (MMA/TBB) resin cement with the 10-methacryloyloxydecyl dihydrogen phosphate (MDP) contained primer. The shear bond strength test results indicated that the surface oxidation by the abrasion is the main contributor that improved the adhesive bonding rather than other effects such as mechanical roughening or alumina remain.

Chemical alteration of Ag-Pd-Cu-Au alloy surface by alumina air-abrasion and its effect on bonding to resin cement.

The goal of this study was to investigate the chemical alteration of a dental alloy surface by alumina air-abrasion and its effect on bonding to resin cement. Alumina air-abrasion was carried out on an Ag-Pd-Cu-Au alloy. The surface morphology and chemical state of the abraded alloy were characterized. The effect of the air-abrasion on the shear bond strength between the alloy and a methyl methacrylate/tri-n-butyl borane (MMA/TBB) resin cement with some primers was evaluated. The surface characterization revealed that the alumina air-abrasion mechanically roughened and chemically altered the surface. The chemical alterations had two effects: (1) abraded alumina particles remained on the alloy surface and (2) copper ions were oxidized in the alloy surface. As the result, the shear bond strength test indicated that 10-methacryloyloxydecyl dihydrogen phosphate (MDP) contained primer worked with the abraded alloy surface, whereas it did not work with the non-abraded alloy surface.

Estudo comparativo in vivo da osseointegração em duas diferentes superfícies de implantes em liga TiAlV: caracterização topográfica, análise de frequência por ressonância e histométrica / Comparative study in vivo of osseointegration on two different surfaces of TiAlV alloy implants: topographic characterization, resonance frequency and histometric analyzes

Objetivo: Avaliar o comportamento biológico do tecido ósseo ao redor de implantes manufaturados em liga Ti-6Al-4V diante das superfícies modificadas por jateamento de óxido de alumínio seguido condicionamento ácido (SBAS) e a superfície usinada (MS). Material e Métodos: Dez coelhos receberam aleatoriamente 20 implantes de hexágono externo com dimensões de 4,0 mm de diâmetro e 10 mm de comprimento em suas tíbias direita e esquerda, sendo um implante de cada superfície em cada tíbia. Os implantes de ambos os grupos foram analisados através de microscopia eletrônica de varredura (MEV-EDX) e microscopia de força atômica (AFM). Discos com as mesmas superfícies foram submetidos à análise de rugosidade média (Ra) e secção transversal. Nos períodos de 3 e 6 semanas foi mensurado o coeficiente de estabilidade primária por meio da análise de frequência por ressonância (ISQ), seguido da eutanásia dos animais. As peças obtidas foram submetidas ao processamento de inclusão em resina fotopolimerizável e levadas ao micrótomo para corte calcificado. Foi mensurada em porcentagem a extensão linear de contato entre tecido ósseo mineralizado e implante (ELCOMI) e área óssea neoformada (AON). Os dados foram submetidos à análise de variância e ao teste t de Tukey. Resultados: MEV e AFM mostraram diferenças na topografia das superfícies. Os valores médios obtidos pelas análises de frequência por ressonância, Ra e secção transversal para SBAS foram estatisticamente superiores (p<0,05) quando comparados a MS. Os valores médios em porcentagem de ELCOMI para SBAS foram de 69,65 e 71,56 respectivamente para 3 e 6 semanas, enquanto para MS os valores médios foram de 54,06 e 55,99 respectivamente para os mesmos períodos. Os valores médios de AO no grupo SBAS foram de 69,85 e 79,60 para os períodos de 3 e 6 semanas, enquanto para MS os valores médios foram de 59,59 e 74,32 respectivamente nos mesmos grupos. Houve diferenças estatisticamente superiores (p<0,05) nos implantes SBAS para a ELCOMI nos períodos de 3 e 6 semanas e AON no período de 3 semanas. Conclusão: A modificação na superfície nos implantes SBAS proporcionou alterações na topografia dos implantes, promovendo um maior contato entre tecido ósseo e a liga de titânio, permitindo melhores níveis de osseointegração. Relevância clínica: Implantes manufaturados em liga de Ti-6Al-4V modificados por jateamento de óxido de alumínio seguido condicionamento ácido (SBAS) apresentam bons níveis de osseointegração e podem ser usados com segurança para reabilitação protética de pacientes(AU)

Objective: Evaluate the biological behavior of bone tissue around implants manufactured in Ti-6Al-4V alloy before surfaces modified by aluminum oxide blasting followed by acid etching (SBAS) and machined surface (MS). Material and Methods: Ten rabbits randomly received 20 external hexagon implants with dimensions of 4.0 mm in diameter and 10 mm in length on their right and left tibiae, one implant of each surface on each tibia. The implants of both groups were analyzed by scanning electron microscopy (SEM-EDX) and atomic force microscopy (AFM). Disks with the same surfaces were submitted to analysis of average roughness (Ra) and cross section. In the periods of 3 and 6 weeks, the primary stability coefficient was measured by means of resonance frequency analysis (ISQ), followed by euthanasia of the animals. The obtained pieces were submitted to the inclusion processing in photopolymerizable resin and taken to the microtome for cutting without decalcification. The bone interface contact (BIC) and neoformed bone area (NBA) was measured in percentage. Data were submitted to analysis of variance and Tukey t test. Results: SEM and AFM showed differences in surface topography. The mean values obtained by the resonance, Ra and cross section analyzes for SBAS were statistically higher (p <0.05) when compared to MS. The mean values in percentage of BIC for SBAS were 69.65 and 71.56 respectively for 3 and 6 weeks, while for MS the mean values were 54.06 and 55.99 respectively for the same periods. The mean values of NBA in the SBAS group were 69.86 and 79.59 for the 3 and 6 week periods, while for MS the mean values were 59.59 and 74.32, respectively, in the same groups. There were statistically superior differences (p <0.05) in SBAS implants for BIC in the 3 and 6 week periods and AON in the 3 week period. Conclusion: The surface modification of the SBAS implants provided changes in the topography of the implants, promoting a better contact between bone tissue and titanium alloy, allowing better levels of osseointegration. Clinical Relevance: Implants manufactured in Ti-6Al-4V alloy modified by aluminum oxide etching followed by acid etching (SBAS) present good levels of osseointegration and can be safely used for prosthetic rehabilitation of patients(AU)