Fig. 9. Plot showing the correlation between the Integral (I) measured at implant placement and the bone density at the sites of implant placement. Best fitting lines are also shown. Legend: squares and full line, undersized sites; circles and dash-dot line, standard-prepared sites. triangles and dot line, tapped sites. The slope of the line corresponding to the undersized sites is significantly greater than those of the other two lines, which don't differ significantly between each other.