The aim of this study was to make a comparative analysis between the bone response to machined and sandblasted implants. The sandblasting was done with 150-ìm aluminum oxide particles. Under scanning electron microscopic examination, the machined implants presented typical machining grooves, while a very rough, highly irregular surface with depressions and indentations was present on the sandblasted implants. Light microscopy showed a different bone growth pattern on machined (implantopetal growth) and sandblasted (implantofugal growth) implants. No negative effects on the rate of bone growth were observed in spite of the presence of aluminum ions. The histomorphometric analysis showed that sandblasted implants presented, from the third week onwards, a significantly higher contact percentage (P .0001). These values could point to higher osteoconductivity as a result of the higher surface roughness of sandblasted surfaces. Schlagwörter: bone growth, sandblasting, surface roughness, titanium implants