Size for Immediate Implant

The tooth #7 was fractured in a 67-year-old lady (Fig.1).  Treatment plan is extraction of the affected tooth and placement of immediate implant.  The question is how to close the extraction socket with a proper sized implant without exposure of implant threads (rough surface).

CT taken before the fracture shows that the mesiodistal and buccolingual widths of the tooth at the crest in axial section are 4.61 mm and 5.98 mm, respectively (Fig.2). 

Coronal section shows the height of the alveolus is 21.05 mm (Fig.3); the widths are 7.66 mm and 5.65 mm at the crest and the narrowest area, respectively.

Which of Tatum tapered implants is the most appropriate, 4x17 mm (Fig.4), 4.5x14 (Fig.5) or 5x11 (Fig.6)?

I took a look at the case.  I think that the 4.0 or 4.5 diameter implant is more appropriate.   The 17 length is ideal .  I suggest the smaller diameter implant due to fact that we are replacing a lateral.  I would graft the superior threads with bone allograft.   Bernee Dunson

Xin Wei, DDS, PhD, MS 1st edition 10/27/2011, last revision 10/31/2011