Zimmer has announced release of their Angled Tapered Abutments. These abutments compensate for off-axis implants for expanded surgical options, such as All-On-4 type situations, to maximize the use of available bone, avoid the alveolar nerve and sinus, and minimize cantilevers for prostheses.
Angulation correction: 15° Angled Tapered Abutment: Corrects up to 30° of divergence 30° Angled Tapered Abutment: Corrects up to 45° of divergence
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 aredigitally stored at our laboratory. We archive master andopposing models, as well as components of the final case,such as monolithic restorations, fixed copings, partialframeworks, CAD/CAM milled bars, and patient-specificimplant abutments. We recently added a back-up systemthat stores these files for two years; implant abutmentsand bars are kept for 10 years. If needed, models andparts can be recreated for future use - just another benefitof 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
It is the mutual goal of both dentist and laboratory to create lifelike restorations that seat efficiently and satisfy patients. When seating posterior restorations, the primary determinants of success are interproximal and occlusal contact, contour, shade, and marginal integrity. Of these, interproximal contact is a subject we often discuss with our clients. We thought it would be helpful to share our “standard” for contact design in the following drawings and descriptions, which we have found satisfi es the majority of our clients. If you prefer a different design please use this reference as a guide to communicate your preferences. This information, added to your “customer profile,” will enable us to always meet your expectations. 1. Contacts should be football-shaped and located below the marginal ridge. The ROE standard is to establish broad, rather than point contact. Note how the surface area of the contact is approximately 1/3 the width of the occlusal table. The ROE standard for tightness is for the restoration to “hold” shim stock (12 microns) when fully seated on the solid model.
2. Some dentists request extra broad contacts and want contours as shown from this occlusal view. X and Z show ideal contour while W and Y show “extra-broad” contact. The image to the lower left shows the proximal view, and the outline in red indicates the broadened contact.
3. From an occlusal perspective, contact between the cuspids, bicuspids and 1st molars should be placed 1/3 lingual and 2/3 buccal so the embrasures are deeper on the lingual than the buccal. The contact between the 2nd and 3rd molars is placed approximately 1/2 buccal and 1/2 lingual.
4. Proximal surfaces gingival to the contacts should be contoured so the embrasure is symmetrical and triangular in shape, as indicated in red.
5. This diagram shows an under-contoured buccal embrasure as indicated by Y. Proper contour is shown with the dotted line indicated by X.
6. From a gingival–occlusal perspective, contacts are positioned as shown. Maxillary posterior contacts move progressively towards the gingiva as they move away from the midline, while mandibular posterior contact points are at the same general level or plane.
Special thanks to Dr. William Sweeney Jr. for his contribution to this article.
Precious metal costs continue to skyrocket. In an effort to simplify our pricing we now offer fl at-fee pricing on two more of our C&B restorations. Semi-precious PFM’s (Pd 25% Co 42%, Cr 20%, Mo 6%, Mo 12% ) are now $185 per unit ,and our yellow, full-cast crown (Pd 79%, Au 2%, Sn 8.4%, Co 5%) is just $150. We offer a fi xed-fee for all our non-precious, semi-precious, and all-ceramic restorations.
It is accepted practice that during an implant impression an x-ray should be taken to ensure the transfer post is fully seated in the implant. Lately, we have had discussions with dentists regarding the benefi t of an additional x-ray at the seating appointment to ensure the abutment is fully engaged. An abutment not properly seated will produce high occlusion or post-placement screw loosening. It is recommended that x-rays be taken at both the impression and seating appointments.
HemCon Dental Dressing is a hemostatic product that was invented for U.S. forces on the battlefield.The company, HemCon Medical Technologies Inc., introduced their product to the dental fi eld becauseof its multiple benefits such as sutureless surgery, reduced chairtime, and quicker healing. The dressingis available in 10mm x 12mm blocks or 1” x 2” strips that are easily trimmed and set in place. The effects are almost immediate and the dressing dissolves within 48 hours. The Portland-based company can be reached by visiting www.hemcon.com.
Thommen, a Cleveland, Ohio based implant company, has two announcements. Now, due toThommen’s compatibility with our scanning and milling equipment, we can create custom titaniumand zirconia abutments. Until recently we have been limited to restoring Thommen implants with stockabutments. Also, Thommen now offers a multi-unit abutment (straight or angled) compatible with Nobel Biocare’s design, which allows us to fabricate titanium bars for Thommen overdenture cases.
When non-vital roots are present, consider the Zaag attachment from Zest Anchors. Zaag is a partial denture or overdenture root-borne abutment that is cemented into a prepared site. Once seated, a conventional pick-up and curing technique is used to attach the Zaag into the prosthesis. When a stable root is present, Zaag is a wonderful alternative for stabilizing removable prosthetics. Visit the website www.zestanchors.com.
Easy Abutments, such as Zimmer’s Short, Nobel’s Snappy and Straumann Solid Abutments, are popular options due to their ease-of-use and decreased component cost. The simple impression technique works by snapping an implant replica onto the fi nal abutment (placed at surgery), instead of using the traditional impression post. In most systems, the abutment and screw are separate, allowing the abutment to be torqued post transfer. The one-piece Straumann Solid Abutment is different because the abutment does not have an independent screw. The abutment must not be re-tightened at any time after the impression. If it is turned, the impression will not be accurate, and consequently the crown will not fi t. The process for Easy Abutments is straight forward, and the possibility of laboratory error has been virtually eliminated by this implant design.