Cardanol acts to stabilize asphaltene particles in crude oil, but its derivative polycardanol, synthesized with BF3.O(C2H5)2 as initiator, exhibits divergent behavior, acting as both asphaltenes stabilizer and flocculant. This behavior could be related to structural differences in polycardanol samples. Therefore, in this work, we study the influence of some polymerization conditions (monomer purity, initiator concentration, and reaction time) on the structures and molar masses of the reaction products, and the reaction conversion. The materials were characterized by size exclusion chromatography and hydrogen and carbon nuclear magnetic resonance. When reacting with distilled cardanol, the conversion, the molar mass, and the homogeneity of structures increased as increasing initiator concentration in the range tested (1-3% m/m). For both monomers (different purity degrees), when using a lower initiator concentration (1% m/m), the product contained a larger amount of unreacted monomer and different structures were obtained due to the occurrence of rearrangements. The presence of triolefinic molecules in the monomer provoked crosslinked structures for higher initiator concentration (2-3% m/m). This study elucidated the differences among the reaction products of polycardanol.

Our work presents a comparative study of morphological characteristics and the osteogenic potential of MC3T3-E1 cells on different modified surfaces of titanium: nanostructured TiO2 with 20 and 100 nm nanotube diameter, and sandblasting and acid etching, commercially known as SLA. Nanostructured TiO2surface was prepared by anodizing of titanium plates, while SLA surface was provided by commercial supplier. Surfaces were characterized by SEM, EDS, AFM, and water contact angle measurements. In order to evaluate cell response,in vitrotests of MTT, alkaline phosphatase and staining with alizarin red were performed. From the results ofin vitro tests, 100 nm nanotubular surface showed lower levels of cell mineralization, differentiation and adhesion. In general, 20 nm TiO2nanotubular and SLA surfaces promoted similar response from osteoblasts. As a result, 20 nm nanotubular surface proved to be a possible alternative to SLA surface with potential for use in oral implantology market.

The study of dental implant surfaces is relevant in order to better understand the interaction of the titanium surface and the surrounding tissues. Clinical success is achieved not only because of implant material but also because of other properties as implant design, surface treatment and quality. In this work, we report a detailed surface investigation of three major Brazilian made implants and compared them to a world-known implant. The surface composition and morphology were investigated by using X-ray photoelectron spectroscopy and scanning electron microscopy. Results of a biological test implemented in order to verify the bioactivity of the implant surface are also presented.