Twenty-four Astra titanium dental implants were inserted bilaterally, three on each side, into the mandibles of four dogs to study mucosal and bone-implant junctions. After a healing period of 6 months, the dogs were sacrificed and bone sections with implants were removed and processed for histologic evaluation. All implants were stable, and radiographs disclosed complete bone healing. The surrounding mucosa closely resembled that surrounding natural teeth. Histometric analysis of the alveolar bone revealed that, on average, 61.3% of the implant surface interface was integrated in the bone at the light-microscopic level. Palabras clave: dog, histomorphometry, implantology, light microscopy, mandible, osseointegration, screw implants, transmission electron microscopy