Do you consider the Trefoil system to be an efficient solution?
Yes, the Trefoil system is an efficient way to get a high-quality immediate prosthesis. Since starting immediately loaded bridges about 18 years ago, reductions in time and cost have improved treatment acceptance dramatically, and the Trefoil system is an important continuation of this.
What are the key stages in the Trefoil system where you save time in comparison with conventional fixed full-arch treatments?
The real time-saver is the fact that there is no temporary bridge in the Trefoil system workflow and that there are fewer steps required than for a conventional custom bridge. With the Trefoil system you cut out all of the appointments required to produce a definitive bridge, e.g., impressions, jaw relations, tooth try-in, framework try-in and definitive bridge insertion. This is significant for the clinician as well as the patient. We treat many patients that live a considerable distance from our practice and the ability to provide a definitive bridge almost immediately will save them airfares, travel costs and time off work.
The impression procedure is much quicker than other treatments – it takes me around 10 minutes. I don’t do a wax-rim type of jaw relation, so my jaw relations take about 5 minutes. Then the insertion of the bridge typically takes about 15 minutes; but I allocate about 30 minutes to have a chat with the patient and go through various things such as oral hygiene instructions.
An estimation of active working time based on median time observed in clinical use.*
In total, how much time do you spend on treatment with a case using the Trefoil system?
In total, an experienced clinician and lab will require around six hours of working time.
I spend around 2.5 clinical hours on treatment at the practice, including both surgical and restorative procedures. Compared with conventional full-arch treatments, I can save around 4.5 clinical hours. If the surgical and restorative steps are carried out separately, and if you do a wax rim and a try-in before bridge insertion, treatment takes around 3.5 clinical hours.
A clinician that does both surgical and restorative work will immediately save a lot of time with the Trefoil system. I spend a similar amount of time on the surgery as with conventional treatments and, like with learning any new surgical technique, this has gradually reduced with the learning curve. It’s important to note that comprehensive training is recommended before starting with the Trefoil system.
Fig. 1. Mandibular residual ridge
Fig 2. The central implant is inserted using the positioning template.
Fig 3. The Transfer Abutments and a non-engaging temporary abutment are placed to construct the verification index. The Transfer Abutments are luted with light-cured resin to fix the verification index.
From a laboratory perspective there is a time saving as well as a cost saving. With the pre-manufactured bar there is no need to design the bridge framework. The fit is determined in the lab utilizing the fixation mechanism, so a surprise is less likely than when receiving a custom framework from a third party, where there can be scanning or milling errors. The biggest factor is the time saving in waiting for the framework – the lab can get on with the production of the bridge and not have to wait and track framework delivery.
Fig.4. Verifying the fit of the Trefoil bar.
Fig. 5. Fixation of the mechanism using either laser welding or resin. The bar shown here is laser welded.
Fig. 6. Articulation of the bar to the opposing arch.
Fig. 7. Conventional wax-up and processing for a wrap-around hybrid acrylic / titanium fixed prosthesis.
How would you describe the prosthetic workflow of the Trefoil system?
The flexibility of the Trefoil system allows for variations in prosthetic workflow to suit the clinicians involved and their respective practices – it can be managed a number of ways.** For instance, because I do the surgery and prosthetics, I combine the impression and jaw relation at the time of surgery then provide the bridge at a separate appointment. If the treatment is divided, then there could be more prosthetic appointments for jaw relations and try-in for example. The impression or verification part of the treatment is very efficient. A surgeon with little experience in implant impressions could provide this at the time of surgery, save significant time and improve patient comfort by lessening the need for manipulation of tissues immediately after the operation.
Fig.8. Delivery of the final bridge on the day of surgery. Occlusion is checked for even contact and anterior guidance. Accessibility for cleaning is verified and screws are tightened to 35 Ncm. Access holes are sealed with Teflon and composite.
How do you expect the introduction of the Trefoil system to affect your dental practice?
The most significant impact comes from the time- and cost-efficiency of the Trefoil system. With pre-manufactured components, no multiple customization and no provisional phase, it will allow me to treat more patients with a fixed, full-arch solution. That is a big growth potential for the practice, but also more importantly for the community at large to be better served.
How would you describe the main patient benefits of the Trefoil system?
Getting a definitive prosthesis is fast: there is no provisional phase, a simplified workflow and less active working time for both practice and lab.
Not only is the time-efficiency convenient for the patient, but it has the potential to translate into greater affordability. This is consolidated further by the efficiency of pre-manufactured, pre-assembled components. It forms a great alternative to fixed-removable treatments and gives more people access to something that feels like a third dentition.
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*Data on file from use by experienced clinicians and labs.
**For more information please see the Trefoil Procedures Manual.
Case images courtesy of Dr. Glen Liddelow and Michael Standish Dental Laboratories.