How to Place Neighboring Implants Parallel to Each Other (Part III)?

The implant at the site of #14 happens to be designed to be parallel to the tooth #13 and the drill at the site of  #15 without too much thinking (Fig.1).

When RT2, bone expanders 2.6, 3.0 (Fig.2) were used, they were intentionally oriented parallel to the the crown axis of the tooth #13.  The X-ray shows that the tip of the bone expander 3.0 is too close to the tip of #13 root.

Effort was exerted to correct the trajectory of bone expanders using the crown of the neighboring tooth as a guide.  There was not much improvement (Fig.3 E4.3: bone expander 4.3).

The final tap 6x17 seems to be parallel to the long axis of the crown of the neighboring tooth (Fig4: black line).  At that time it was not realized that the long axis of the root (red line) matters the most.  It is not the same as that of the crown!  The implant at the site of #15 does not give us any guidance since small portion of it is exposed (below arrowheads).

What will be the most reliable clinical guide?  It has been used before.  The answer will be found somewhere in this page.  Keep searching.

Xin Wei, DDS, PhD, MS 1st edition 09/30/2013, last revision 10/01/2013