D Implant for Lower Molar? 

A Caucasian lady has a failing bridge in the lower right quadrant.  After sectioning the bridge, the tooth #31 is extracted and an immediate implant is placed (7X11 mm).  A 5x14 mm tapered implant is planned to be placed at the site of #30 six weeks later (Fig.1,2).   Since the top of the ridge is severely atrophic and the mesiodistal width is quite wide, I wonder whether we should place a D2 or 3 short implant instead.  My concern is how to create a D shaped osteotomy without offset D osteotomes, although bone scalpel and bone blade osteotomes can be used to create an initial osteotomy.  Thanks.

Xin Wei, DDS, PhD, MS 1st edition 09/21/2012, last revision 09/21/2012