What are Rosen and Powerball screws?
Direct to MUA screws, like Rosen screws and Powerball screws, allow direct to MUA connection without the titanium base (titanium chimney). These screws ideally allow for the elimination of the titanium base or titanium chimney in an all on x prosthesis.
Why direct to MUA?
The argument for these direct screws is that they eliminate the chance of the ti bases coming unluted from the prosthesis. Depending on whether the lab uses a ti base or a to chimney and which ti base they use this can be an issue. Not all ti bases are the same and not all luting materials are the same. Titanium bases from different companies make different claims but in general the shorter they are the more likely they are to have luting issues. If you look at the bottom of the page on our zirconia framework page, you’ll see a study showing that different resin cements have different bonding strengths. Therefore, not everyone is going to have these issues at the same percentages. This video explains things really well.
Who is using Rosen screws and Powerball screws?
These are mostly in use by dentists that are milling their own prosthesis. They are still experimental and will likely take awhile to find out what drawbacks they may have. The individuals using the screws tend to be very knowledgeable and well trained doctors that deliver excellent results. Below is a case from LSK. Another dentist put the post on another fb group. The treating dentist actually doing the case saw it and said he didn’t like it and went back to traditional method. It’s an all too familiar example of someone showing something really sexy and looks cool on instagram but failing to work out in the real world.
Why not use direct to MUA screws?
They are new and not many labs or dentists know about them. This is an issue in and of itself. However, the bigger issue is they have not been around long enough to start showing what their problems will be. Everything ends up having some kind of issue and it takes time for those issues to rear their ugly head. You can see that labs are working to try to figure these things out and some are hesitant until others try them out for awhile.