Zirconia was introduced to dentistry a little more than ten years ago and has been the go-to material in our dental lab for some time.
We like it for its versatility, due to its strength and esthetics. When it comes to implant restorations, screw-retained zirconia crowns have become the favorite of our customers, surpassing cemented restorations.
Let’s go over a few different areas to compare and contrast screw-retained zirconia crowns, including: Retrievability, clearance and angulation, complications, cost savings, and screwmentable options.
An implant is a large investment, and we can help to make sure that your patient leaves your office with a smile.
One of the main advantages of screw-retained zirconia crowns is the ease of retrieval.
If the crown needs to be recovered, or the screw needs to be changed or tightened, the restoration can be removed by accessing the screw through the screw channel. Once you have made adjustments or tightened a screw, you can fill the channel with Teflon tape, and seal the opening with composite or acrylic material.
With cement-retained crowns , you will need to use a temporary or implant cement in order to make the crown easier to retrieve. In many instances, a cement-retained crown must be cut off if access to the abutment or screw is needed.
Clearance and angulation
Screw-retained zirconia restorations require a minimum of 6 mm of restorative space, making them an ideal option when clearance is tight.
Cement-retained crowns, on the other hand, need 7-8 mm of clearance. These measurements must be taken from the implant platform.
With off-angled implants, custom abutments and cement retained crowns used to be the best option and they still sometimes are. A custom abutment can be fabricated to bring the abutment inline with the adjacent teeth and the crown made to cement on.
But, for many cases, we now have Angled Screw Channel (ASC) options for different implants that allow us to correct for situations where the screw channel comes through an esthetic area like the buccal or facial of a crown. It is important to note that using an ASC requires a different driver than is normally used for an implant.
Please contact us at First Choice Dental Lab if you would like to discuss our ASC options.
Excess cement being left behind is one of the leading causes of peri-implantitis.
Screw-retained zirconia crowns are cemented in the lab under ideal conditions, so all cement is able to be cleaned up before insertion.
Custom abutments can be designed with supragingival margins making it easier to completely remove all cement. However, this may create a less esthetic outcome for the patient.
Cost savings for screw-retained restorations
Both screw-retained and cement-retained crowns are fabricated using CAD/CAM production.
Screw-retained crowns usually provide a cost savings over cement retained crowns because of the use of pre-fabricated titanium bases and a 1-step design process. A cement-retained crown over a custom abutment has the additional cost of the abutment fabrication and additional design work.
A screwmentable crown is a cemented crown over a custom abutment that has a screw access channel designed into it.
This allows for the benefits of a custom abutment, such as angle correction and emergence profile, while still providing an access hole for retrievability. It is important to look at path of insertion on these types of cases as it could prevent removing the crown/abutment later if the insertion angle is different between the implant and crown.
If you would like to order a screwmentable crown, simply fill out our lab slip for a custom abutment and cement-retained crown, and request a screw access hole in the crown.
Your Implant Experts
At First Choice Dental Lab, we pride ourselves on having over 150 years of technical experience in our implant department.
This experience, combined with our CAD/CAM technology for design and production, allows us to fabricate high-quality implant restorations. Our resume includes, but is not limited to, screw-retained crowns, custom abutments, temporary implant crowns, full-arch zirconia restorations, hybrid screw-retained dentures, and locator dentures.
If you are looking for technical help and options to make sure your patient walks out with a smile, please contact us at 866-791-7025, or complete the form below!