The buccolingual width of the ridge is 5 mm on the top (Fig.16 coronal section).  The ridge will be trimmed down ~ 2 mm so that the width will be 6 mm to accommodate 4 mm implant (Fig.17).  The trimming is oblique (lower buccal, higher lingual, parallel to the occlusal plane of the opposing tooth). 

The drawback of the narrow implant (4 mm) in the molar region is potential fracture of the thin coronal wall of the implant and/or abutment screw.  IBS implant is made of Titanium V, which is stronger than Titanium IV.  Furthermore Magicore is a type of 1-piece implant (Fig.17 green (implant portion) and pink (abutment portion)).  There is no issue of breakdown of implant wall or abutment screw.  A solid abutment is used to facilitate restoration (yellow).

Upright Last Implant Placement Xin Wei, DDS, PhD, MS 1st edition 01/23/2017, last revision 08/15/2018