June 2010, Volume 6, Issue 6
Published by AEGIS Communications
Atlantis™ Patient-Specific Abutments
These abutments are individually designed to meet each patient’s unique needs as well as exceed their expectations.
Implant dentistry has evolved to become a predictable, cost-efficient, and effective way to replace missing or unrestorable teeth. Many implants are now being placed in between existing natural teeth as well as into extraction sites at the same visit as tooth extraction. Implants placed in these locations present esthetic and functional challenges for the restorative dentist that are different from those found with conventionally placed implants. In cases where a cement-retained implant solution is required, the Atlantis™ Abutment solution (Astra Tech) can be used to meet these more challenging situations easily, economically, and with great success.
When implants were first offered to patients, they were used to replace complete arches of missing teeth. The resulting prostheses were so different in appearance and function compared to conventional fixed and removable prostheses that they required new nomenclature (ie, fixed hybrid, high-water bridge) to describe them. While patients were pleased with the functional results of their implant-retained prostheses, the esthetic results were often less than ideal.
Patients have now come to expect that their implant restorations will not only function like natural teeth but also will look like and blend in with the natural teeth that are adjacent to and opposing them. Ceramic abutments, improved laboratory techniques, and the use of cement-over restorations that eliminate the screw access chamber have all helped to accomplish this goal. However, the foundation of the restoration, the abutment, is the single most critical factor in creating a natural-looking implant-supported crown.
The emergence profile, or the way the implant emerges through the soft tissue into the oral cavity, determines whether the implant restoration will look like a natural tooth; this contour is determined by the prosthetic abutment. Abutments can be purchased from the implant manufacturer and used in their stock state, or the dental laboratory can modify them before the prosthetic crown is fabricated.
Regardless of the type of abutment that is used, the basic shape of the abutment is circular. While the circular shape mates properly with the implant body interface, it does not develop the soft tissue into the shape of a natural tooth. The shape of the emergence profile may need to be trapezoidal, ovoid, or oblong depending on the tooth being replaced; however, it is never circular.
To compound the problem, stock abutments are manufactured according to the diameter of the implant platform that is being restored, not according to the size and shape of the tooth that is being replaced or the replacement crown that it needs to support. As such, dentists have no choice but to use the same abutment whether restoring a mandibular lateral incisor (a small, ovoid tooth) or a maxillary molar (a large, trapezoidal tooth).
Another trend that has been observed in current implant dentistry is that immediately placed implants tend be located much further subgingivally than implants placed in well-healed post-extraction bone. This results in the prosthesis–implant interface being so far subgingival as to make the complete removal of cement difficult or near impossible. Residual cement left at the prosthetic interface often results in red, irritated soft tissue which, if left untreated, will lead to bone loss and subsequent loss of the implant.
Fortunately, there is a simple solution that addresses both the functional and esthetic issues presented with using a modified stock abutment. Atlantis Abutments are uniquely designed for each implant in each individual patient’s mouth. Through the utilization of 3D imaging and the sophisticated Atlantis VAD™ (Virtual Abutment Design) software, Atlantis Abutments are designed based on the final tooth shape and incorporates the clinician’s design parameters within the process.
For example, the clinician can specify the margin design, the subgingival depth, and whether the abutment should have a retentive surface or not. The Atlantis VAD software will then design the abutment in a virtual environment for the manufacture of an ideal, patient-specific abutment. Because the abutment design process is done completely digitally, there is no waxing, milling, or hands-on work required by the dental technician. Conventionally fabricated custom abutments are unique products of the technician’s work and, as such, are impossible to accurately duplicate.
Alternatively, because Atlantis Abutments are designed using digital technology, it is possible to order multiple abutments that are exactly the same as the original abutment should a replacement abutment be needed at a later date without the need for a new impression. Another benefit of the Atlantis solution is that, if necessary, the duplicate abutment can be altered to compensate for changes in the soft tissue margin surrounding the implant, thus eliminating the need for a new impression or for the abutment to be modified intraorally.
Once the abutment is designed, the laboratory technician and/or dentist can elect to receive a digital representation of the abutment. The image is not just a static view of the abutment; rather it is a 3D image that can be easily manipulated on the screen to show every angle of the abutment and how it relates to adjacent and opposing teeth (Atlantis™ 3D Viewer).
The completed abutment can be milled in titanium, GoldHue (gold-shaded titanium), or a white or shaded zirconia depending on the clinician’s preference. Turnaround time for the design and manufacture of Atlantis Abutments are, in some cases, as quick as 1 day. Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, show a case completed with the Atlantis Abutment.
Getting started with the Atlantis solution is easy and straightforward for both the clinician and the laboratory alike. All that is needed to order an Atlantis Abutment is simply an fixture-level impression of the implant, a model of the opposing arch, and a bite registration. As an added benefit, the dentist can continue to use the laboratory of his/her choice; there is no need to alter long-term relationships between the dentist and the technician.
In today’s competitive dental marketplace, Atlantis is a surprisingly cost-effective solution compared to conventionally fabricated custom abutments, with costs for an Atlantis Abutment being oftentimes less expensive than a technician-cast or milled custom abutment. One of the key differences between Atlantis and other CAD/CAM systems on the market is that there is no investment in materials, hardware, or software for the dentist or the laboratory technician. More importantly, because the abutments are designed by the intelligent Atlantis VAD software rather than by a technician, there is no learning curve necessary for ideal abutments to be created every time—starting with your very first case. For further flexibility for both the clinician and laboratory, Atlantis is compatible with all major implant systems including Astra Tech, Nobel Biocare (including the NobelActive line of implants) as well as Straumann (tissue and bone-level implants), Biomet 3i, and Zimmer Dental.
This article was written by Ethan A. Pansick, DDS, MS; and Ralph C. Attanasi, Jr, DDS, MS.
For more information, contact:
The preceding material was provided by the manufacturer. The statements and opinions contained therein are solely those of the manufacturer and not of the editors, publisher, or the Editorial Board of Inside Dentistry. The preceding is not a warranty, endorsement, or approval for the aforementioned products or services or their effectiveness, quality, or safety on the part of Inside Dentistry or AEGIS Communications. The publisher disclaims responsibility for any injury to persons or property resulting from any ideas or products referred to in the preceding material.