Every thing starts from planning. It is proven by many researches that a minimum distance between the implants, and between implants and teeth should be kept. Too lingual or too buccal position of the implant resulting soft tissue trauma or hygiene problems. The solution is guided surgery. A surgical guide produced from a CBCT allows to use maximum of the bone by placing bigger implant in length and diameter with better capacity to withstand heavy load.
The next challenge is to create a restoration that has a passive fit. Monitoring marginal seal and absence of micro-gap using a simple x-ray is not a serious approach.
Up to this moment, there is no mean to check a fit of a framework of fixed restoration in vivo. The only way to achieve a passive fit and a marginal accurate seal is to eliminate from the working process bad factors that were proven, in vitro, and found to be harmful for the accuracy. These factors are: impression transfers, impression copings and lab analogs.
Direct impression with G-Cuff eliminates these three elements and assures a passive fit.
According to Zipprich study about interface micro-gap I don't see any justification to use other connections but tapered. Flat connections infection around the implant, continuous bone lose and implant loss.
Finally, the preservation of the Peri-implant zone from contamination with remains of cement is very important. Using the G-cuff for cementation, prevents the cement from going into the peri-implant area and prevents peri-implantitis.
In order to guarantee a long survival rate for our implants we need three things:
1. Planning and guided implant surgery
2. Direct impression with G-cuff
3. Clean cementation using G-cuff
4. Implants with tapered connection