In this blog update we are going to look at a new technology that allows us to bend the access holes in screw retained restorations.
Screw retained implant units have always been popular with our surgeons for many reasons but I think a main advantage is the lack of cementation needed at fit, which negates any associated risks of retained cement causing issues sub gingivally later on.
However the access hole can be a problem in certain situations where the emergence angle leaves the hole coming through the aesthetic facings of the crowns, which often then means we have to switch to an abutment and cement retained restoration.
As our regular followers will know we have a belief that CAD/CAM restorations really are the only way to go when designing and producing implant sub structures to ensure the best clinical results, but this did mean there was no solution to the access hole problem as these structures are milled from a solid block of material and therefore the burs had to have a line of sight the section of the element that was being milled.
For a while we have been able to offer angle correction on the access holes for multiple unit cases but nothing was available for single units in CAD/CAM due to the complexity of the milling strategies required.
Thanks to new milling strategies and partnerships it is now possible to offer angle corrected screw retained CAD/CAM crowns on most of the popular implant systems, even down to some narrow platforms such as this Nobel Biocare Replace NP fixture that we restored with Dr Pav Khaira
Angle corrected design
The red tube illustrates the original access hole direction, which would have been coming through the buccal of the crown and the green shows where the access hole was corrected to come out of the centre of the occlusal surface of the crown.
Once we have approved the new correction design the abutment can be milled from chrome with the access hole now corrected to come out of the occlusal of the crown, rather than the buccal where it would have been previously.
By using this new technology we can now have screw retained units with the clinical benefits they bring, without the compromise to aesthetics or the very challenging prospect of the surgeon having to fill the hole and blend the composite to match the surrounding crown in an aesthetic area of the restoration.
This image of the final crown back on the model shows that we have been able to bring the access hole well clear of the buccal of the crown (we will post up final fitted pictures when the patient comes back in for a review with Dr Khaira)
Fitting an angle corrected screw retained crown
For the surgeon these are to be fitted following the same protocols as any other screw retained crown, the only exception is that they must have a specially designed screwdriver, which we will look at below.
To fit these crowns you need a specially designed screwdriver that has a thin shank to allow the head of the driver to engage with the head of the screw but a large head which is similar in design to a rosehead bur, this allows the grooves to stay engaged with the hex in the head of the screw, even if the shank of the driver is angled back.
the engaging head of screwdriver in action
The benefits of using this new solution are :-
All the traditional benefits of screw retained restorations (easy retrievability, no risk of retained cement etc.)
No change to the restorative procedure (you simply need a new screwdriver)
Control of where the access hole will emerge from our restorations
Incredibly cost effective as there is no need for a separate abutment and cement retained crown
Consistency and cost efficiency of CAD/CAM technology
We have also covered the difference between cement and screw retained and the advantages of CAD/CAM technology over traditional lab cast methods in this previous article which we wrote for the dental site Dentinal Tubules, and may be useful if you are unfamiliar with these types of restorations
We just thought we'd share a link to an article we wrote for Dentinal Tubules which tackled the importance of providing a stump shade to the laboratory whenever you deal in all ceramic restorations.
We made a demonstration model and some blank e.max pressings to show how the underlying shade can throw the final match.
We use a painted model (there are ND shade guide resins available for labs to use as shown in this picture) but we have mixed some paints to match the ND shades exactly, which allows us to work on the model systems and crown stones that we know give us great fit results.
Dr Sehmi gave us a stump shade using a standard shade tab
Which allowed Rachelle to match the prep using the paints in our lab which is another advantage of using paints, we can tailor it exactly.
Below is the model that has the same shade as the ND guide painted onto the model
3 blanks pressed from the same emax pellet and all are the same thickness
And as you can see, even with a slight change in ND shade it has an impact on the colour of the emax blanks when they are placed on the model, it's only slight but it's definitely visible.
We have shared this blogpost as it is a very common problem with all ceramic work. If you send the stump shade it really helps to ensure we get the shade right for you.
Better still would be a picture with every case you send. We have all the ceramic technician benches setup with iPads to ensure they can all work with your images in front of them in clear detail. If you take the time to provide the images then they will be used and it will have a positive effect on the final outcome of the case.
We have always believed that the only way to offer our surgeons the very best in quality and value is to stay at the leading edge or technology.
As we have continued to invest in new equipment, technology and training we have hit a bit of a problem. We needed more room to house it all!
Mark has recently had a re design that allows us more room to accommodate our 2 newest team members (Andrius and Lauren) so that we can drive our standards and service levels even higher.
We now have 2 dedicated CAD/CAM stations (with room for the latest scanner that is still to come)
Add along with the scanners we see here there's also the Procera scanner along with a backup storage unit and central CAD file storage drive, and one of our hubs that brings this section of the network together with our other systems in the porcelain department. There's also a wireless storage unit here for connection to the iPad's, but I'll cover them in a bit....
And all of this is at the far end of the new behemoth of a bench that we've affectionately named the Battleship, and here she was on Sunday when just finished.
And here it is in all it's working glory!
But this is only one side of the story. Our ceramists have also been enjoying the fruits of a huge investment too.
All our ceramists now have their own ipad on which the can view all the patient images that as sent in to us. When we are asking for digital photographs of the patient, this is the reason.
Using the crisp, clear and vibrant screens of their ipads the ceramists can really see the detail in your photography, and transfer that into their restorations for you. Up until now we had to share a couple of monitors that were of a good enough quality to display the detail in these images but now it's always there as they work.
On top of this we have also purchase the very best ceramic furnaces available to ensure the cramics do not lose any vitality and clarity when they are fired.
The black furnace on the right is a Dekema Oral Design Furnace, they simply don't get any better.
And of course all this technology and equipment is reliant upon the very best asset we have, some of the most talented and dedicated technicians in the UK.
Of course all this technology and equipment has a very clear purpose, we don't just have it because it's cool (although it definitely is)
The Wireless server that was next door in the CAD department stores images and files that any of the ceramists can access at any time, along with a private network that allows us to share information amongst the group instantly, ensuring we have as close to perfect communication on all our cases as possible,
This is certainly a laboratory you would be happy to send your patients to, we get great feedback from patients that have seen just what we do in the lab and the level of technology involved.
We have even more exciting developments in the pipeline and will update over the coming weeks.
Due to our long experience with a new ceramic alternative material for implant restorations from Bredent we were fortunate to be requested to write an article on it. We have since been asked for permission to reproduce the article and it has now gone on to be published around the world!
We're thrilled that the article has created such interest and it's definitely due to the skills and hard work of the team and in particular Iain Baldwin on this case.
Here's a video of the demonstration case we restored for that magazine article (In Private Laboratory magazine) using the new material visio.lign from Bredent.
This new system is ideal for implant bar restorations due to it's stain resistance, ability to add/adjust in situ, cost efficiency and shock absorbing properties. This combined with the high aesthetics achieved makes Visio.lign a fantastic alternative to ceramic bonded full arch restorations.
This has become the full arch implant restoration of choice with our clients due to it's ideal properties.