Dr. Wang's Response

OVERALL:

Reasons for the failure:

In both of these cases (1,2), provisional crowns were used. This most likely led to movement of the implant during the healing process and consequently, to the failures. In addition, both cases were immediate placements, which led to even less bone for the implant and its threads to grab.  Furthermore, in both cases, the expander was used (BEB and tapping instrument), in which case, not even a healing abutment should be used. 

Solutions for next time:

Remember that there is significantly more bone damage with malleting procedures, and 2-stage surgery MUST be performed. A healing abutment, or even worse, a temporary crown, leads to movement of the implant, and failure. Cover the wound completely so as to prevent any kind of load unto the implant. If a healing cap is absolutely necessary, place the healing cap deeper (shorter cuff), to reduce load unto the implant. 

It is vital to fully understand the Magic Fin Thread, and the factors that lead to failure when using the Fin threads. The bone between the threads must be preserved for the positive effects of the FIN thread to take place (faster healing, balance of physical properties) etc. If the bone between the threads are damaged during placement, then longer healing time (at least 5 months) must be given. The reason for the additional healing time is due to the large bone volume that needs to be replaced in comparison to other implant systems. 

More specifically to the cases:

When Sinus Floor is Thin, Place Implant as Large as Possible..

The process of the provisional coming off and putting it back on at home (experienced by the patient herself), then the process of putting on an angled abutment, healing abutment, etc., led to failure. The bone was healing still, and all of the movement and pressure onto the bone between the threads and around the implant leads to too much force and load than the implant at that point in time could have handled. Should have put closing screw and let heal. 

Keep Sinus Floor Intact..

Firstly, this immediate implantation should have been placed deeper into the sinus due to the fact that the implant threads had very little bone to grab onto. The triangular socket and the thin sinus floor gave only the apical portion of the implant to grab hold. A longer implant should have been used, placed deeper with sinus lift.

Second, Correct use of the BEB technique when lifting the sinus calls for the bone to be drilled up to 1mm from the floor, then, an Expander 1 size smaller than the drill used to begin the lifting process. Make sure that the BEB protocol is exactly understood and the process of the lift with the expanders explained thoroughly. Other reasons for failure in this case are explained in the OVERALL section. 

Pointed Ridge..

The Magicore implant is designed to take care of the pointed ridge without the need to remove the thin portion of the ridge. In this case, the implant could have been placed at the same depth within the bone but with the use of a 3~4mm cuff. Be sure to understand the protocol for Magicore implant size selection. 

1.       Designate the location of the implant within the bone. 

2.       Determine the desired prosthetic margin

IBS Xin Wei, DDS, PhD, MS 1st edition 04/08/2017, last revision 09/06/2018