Astra Tech Implants has a very unique restorative system. Their abutments do not cover the collar of the implant fixture. Instead there is a gap between the implant and the abutment. Many companies are advocating this “platform loading” type of restoration to improve gingival health and decrease bone necrosis around the collar of the implant fixture. I believe this principle helps distribute the forces away from the edge of the implant collar. Some implant companies are using this principle and design in their own implant restorations. I have noticed that this type of connection with their Conical Seal Design has shown great tissue results. At times I can still see some bone loss around the fixture head over time. However, it seems to be less than some other systems.
The abutment selection is rather simple for their Direct Abutment restorations. They have a wide assortment of widths and lengths. Since their abutment attachment is very unique from the traditional attachments it does take some time to adjust to the size of abutment you will need. The company does offer a simple chart system with gingival heights from the implant collar that is very beneficial. One big downfall of the system is that if the implant is not placed deep enough the “gap” in the abutment system may be to coronal and become a plaque trap. Astra provides convenient Direct Abutment packages that include the abutment, analog, impression pick up, and two burnout cylinders. One of the cylinders can be used to fabricate a temporary. The fit of the size 6 direct abutment burnout has some issues at the fixture margin. The burnout doesn’t fit the margin cleanly. I was told that the company is improving its machining and your lab technician may need to make a direct duralay pattern for the 6 direct abutment coping. All other burnout cylinders seem to work well with the other sizes. The abutment carriers are made from plastic in the packages. This carrier is sometimes difficult to remove after the abutment is torqued down and can slip during torqueing. I believe they do have metal carriers that can be bought separately and I would recommend using those.
I have worked with other systems that have a direct type abutment with a scalloped margin to help replicate the gingival form. This makes restoring the teeth much easier and simplifies cement removal. Astra says they are working on a scalloped type abutment. This would greatly expand and improve their restorative system. Their angled abutment comes only in 20 degrees and I do not use it often. The abutment needs to be prepared on a fixture analog or in the mouth and a standard impression taken. If an angle is needed in the prosthesis I would use their uni-abutment system or make a custom abutment. However, this does increase the cost of the prosthesis. Astra has recently made an all ceramic zirconia abutment that can be prepared in the laboratory. It is unique because it is one solid piece of zirconia. Some of the other implant companies have a ceramic abutment but, they are connected in two pieces and are prone to separate.
In 2005 Astra has released all their implants with indexing capabilities with an internal hex. Previously their smallest implant, 3.5 size, did not have indexing ability. This gives the clinician the ability to restore the case in the laboratory and accurately transfer the case intraorally. I find that the indexing of implant is important for larger and more esthetic cases. I use the direct abutment system and take a closed tray technique whenever possible.
The Astra prosthetic instrument set and torque wrench kit are simple and easy to use. It would benefit to have some sort of container to keep all the small parts. The torque wrench is fully adjustable from 10-25 Ncm and is simple to use. The complete restorative set is very simple and easily understood by the novice implant restorative dentist. The company has convenient try-in kits for the profile bi-abutment, uni-abutment, and angled abutment. The uni-abutment adapter is slightly unusual and may take some practice to become proficient.
Although the system is not perfect I would still not have any problems recommending Astra for your restorative needs. In many ways they are innovators in their designs. With this ingenuity there is a learning curve to become fully efficient with all their products. But, like any new product you will have the same learning curve. The company seems to be continuing to improve their restorative abutment, temporaries, and instruments to make implant dentistry as simple as possible.
Review Synopsis
Product
Astra Tech Restorative
The Good
Astra Implants show great clinical studies with hard and soft tissue healing. The placements of their prosthetic components are very simple to master. They are a company with deep pockets and should continue to improve on their implant system
The Bad
Since Astra has a unique restorative design from the traditional implant there is a learning curve. The costs of the components are not inexpensive and it would be beneficial if they had a wider variety of restorative abutments.
The Bottom Line
Overall I would recommend this system. The cost if very standard for the components and the restorative options sufficient for most cases. The best thing about the system is the soft tissue response around the fixture and abutments.