Monday, October 24, 2011
At ROE, noble and non-precious porcelain-fused-to-metal copings are fabricated using the latest selective laser sintering (SLS) technology. SLS is an additive manufacturing technique that uses a highpower laser to fuse small particles of alloy powders into 3-dimensional shapes, i.e. into crown and bridge copings. Coupled with ROE’s sophisticated CAD software, this process produces extremely accurate and homogeneous copings. SLS has allowed us to set fixed-fee pricing on non-precious and noble crowns, which is particularly beneficial in this era of increasing alloy cost.
Fiber Force is a fiberglass mesh composite resin utilized to reinforce acrylic appliances. This very thin, lightcured mesh has many advantages over traditional reinforcement. It chemically and mechanically bonds to acrylic, provides rigidity and strength, is nearly invisible inside of the final acrylic prosthesis, and unlike metal, does not add weight. Fiber Force can strengthen any acrylic appliance, including repairs that require extra fortification. It is particularly beneficial in implant-supported appliances, which are often palate-free or have limited space over attachments or bars.
Cases created through our CAD/CAM iRIS process are digitally stored at our laboratory. We archive master and opposing models, as well as components of the final case, such as monolithic restorations, fixed copings, partial frameworks, CAD/CAM milled bars, and patient-specific implant abutments. We recently added a back-up system that stores these files for two years; implant abutments and bars are kept for 10 years. If needed, models and parts can be recreated for future use - just another benefit of working with ROE.
Implant-bar-supported cases have made a comeback in recent years. At ROE, frameworks for hybrids are designed with the latest CAD/CAM technology and milled from solid blocks of titanium. CAD bars are reverse-engineered from a virtual tooth arrangement, allowing our technicians to factor in space for adequate acrylic surrounding the teeth - this means teeth are less likely to ‘pop-out’. Titanium bars are more rigid than cast alloy, are lighter weight, and have higher tinsel strength. They are available at a much lower cost, regardless of the number of implants, and offer more design schemes than traditional alloy bars. Above are four of our popular bar designs. The first three, using ridge contact design, vary in metal exposure and finish line. The fourth, with space between the ridge and the prosthesis, is a more cleansable option. Patient specific designs are available upon request.
There are multiple steps to fabricate an implant-supported restoration. We thought it might be helpful to provide a list of the appointment sequence. We highly suggest that steps one through six are also followed for splinted implant-borne fi xed restorations.
1 Lab - Create custom trays for open tray impression technique
2 Dentist – Appointment #1 - Capture final impressions with impression posts, x-ray to ensure engagement
3 Lab – Make and return “Fit Verification Jig” and stabilized bite block
4 Dentist – Appointment #2 -Try-in the Fit Verification Jig to ensure the accuracy of the implant model; x-ray to ensure engagement; register bite. If the jig does not fully seat, section, re-seat, and re-duralay. Take a new open-tray pickup impression of the duralay jig and send to it to the lab for a new model.
5 Lab - Mount case and set teeth for try-in
6 Dentist – Appointment #3 - Verify tooth try-in, a reset appointment may be necessary
7 Lab - Fabricate bar and transfer set-up to bar for final try-in or finish
8 Dentist - Appointment #4 - Final seating