Fig.3: Osteotomy is initiated with a 2 mm pilot drill ( D).  In fact, the position of the osteotomy is a little too distal, which is not noticed until a 4.5x20 mm tap is inserted.  The sequence of osteotomy is 2 mm pilot drill, 2.5 and 3 mm reamers and 4.5x20 mm tap at the depth of 20 mm.

Probably due to low density bone and/or over prep, insertion torque of a 4.5x20 mm implant (Fig.4 I) is between 30/35 Ncm.  The implant/abutment (A) remains palatal, but slightly distal. 

After surgery, the patient reveals that he has been on diet to control his weight because of family history of stroke.  It appears that this 74-year-old man has a type of osteoporosis.  Attention should be paid to bone density while osteotomy is being made for every immediate implant, in addition to position and trajectory.  If the bone feels soft, the osteotomy should be less deep than expected.  Under prep is mandatory. 

Low Bone Density or Over Prep Last Next

Xin Wei, DDS, PhD, MS 1st edition 07/08/2015, last revision 02/03/2019