Tissue vs bone level for screw retained overdenture?

I`ve used many systems, bone level and single stage. For every system I`ve been exposed to there is an abutment that goes into the implant and a fixation screw that transfixes the overdenture. Single stage implants are simpler. Please ask your rep if the system he offers has tissue level implants or use a healing abutment from day one.

I'm not sure what you are asking in terms of a screw retained overdenture. There's no such thing. Either the prosthesis is screw retained and is totally implant supported and not removable, called a hybrid or fixed detachable prosthesis (ala branemark) or it's a removable overdenture that snaps onto a bar, locators etc. You don't need an intermediary abutment. Your prosthesis, bar or whatever you want to attach to the implant can go directly to implant level. It is more convenient to have an abutment that brings the platform to tissue level so you don't risk pinching the tissue every time you take prothesis/bar on and off and you can evaluate the fit of your framework more accurately when you can visualize the mating surfaces. The tissue level works nicely with the synOcta abutment screwed into it. The bone levels work fine too by using the Multi-base abutment. I prefer the bone level implant so I can position the finish line of the abutment whereas the surgeon positions the finish line on the tissue level implants.

The bone levels have 2 micro gaps to contend with. The tissue level implants have one. It is best to have one. What have two. Remember we are dealing with multidiciplinary providers. Some have the ability to do X-rays and some do not. To check

I like using the Straumann tissue level when I can and placing them just below the surface. The titanium framework can be milled so it fits directly to this. This will also save a couple hundred per unit for the multiabutment. If you need some angle correction you can use bone level with a multiabutment and combine with tissue level where needed.