In order to test the soft tissue response to contaminated titanium components, 20 clinically retrieved abutment cylinders were inserted in the abdominal wall of 5 rats. Prior to insertion, 10 of the abutments had been contaminated for 1 min and the remaining components for 2 weeks. Five abutments of either group were ultrasonically cleaned in butanol and ethanol, whereas the remaining abutments were only rinsed in saline before being implanted. As controls, 5 newly manufactured abutments were used. After 6 weeks of healing, specimens were prepared of the components and surrounding tissues for morphological analysis. This showed an accumulation of macrophages and a reduction of the number of fibroblasts around the abutments that had been contaminated, irrespective of cleaning procedure, compared with the controls. It was concluded that the contaminated components induced an altered tissue response and that a similar reaction may occur in the clinical situation.