Implants

Accurate Placement of Implant Abutments Using Acrylic Resin Jig

Dentistry Today September 1, 20093 Mins read3.6k Views

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Figure 1. Implant abutments placed on the correct position.

Figure 2. Acrylic resin jig engaging all implant abutments. Note screw hole in the jig.

Figure 3. Implant abutments placed on dental implants using an acrylic resin jig.

Figure 4. Frontal view of dental implant abutments placed in the correct position, after removal of the acrylic resin jig.

Figure 5. Final restorations placed onto the dental implant abutments.

All cementable implant systems are designed to accommodate abutments in several different positions. Usually dental implant abutments are designed to accommodate the final restoration in only one position, especially if a custom abutment is used. When the abutments are placed in an undesirable position, the restoration will not fit properly; and in many cases it will not fit at all.

This could be annoying and inconvenient to the clinician, especially if several implant abutments are to be placed. To prevent this problem from happening, an acrylic resin jig can be fabricated that will simply and correctly locate the proper position of the implant abutments.

The fabrication process of the jig is simple. Once the implant abutments are placed on the implant replicas embedded in the casts (Figure 1), a separating agent (petrolatum lubricant) is placed on the abutment surfaces. Then an acrylic resin material (such as Triad [DENTSPLY Trubyte]) can be used to fabricate the jig (Figure 2). An important point is to allow access to the screw holes by fabricating a hole on the jig on top of the screw access area. With the custom abutment on the model, the placement jig is placed on top of it. (The jig can be removed and replaced easily.)

The jig is used as a placement device to deliver the custom abutment to the mouth in the correct position. It is always advisable for the dentist to evaluate the positioning on the model first. Unscrew the custom abutments from the model and then place them inside the jig. It can fit only in one position.

Then use the jig to transfer the abutment to the mouth (Figure 3). The jig should engage the abutment. The placement jig will guide correct positioning by allowing the angulated abutment to be locked inside the jig. There is one occlusal hole built into the jig for each implant abutment. This allows the abutment screw to be screwed into the implant through the jig.

After the dental implant abutments are placed, the screws can be tightened, and the jig removed (Figure 4). To confirm correct positioning of the abutment, remove, and then reattach the jig to the implant. The screw can be torqued with the torque driver. It is imperative that a radiograph be taken to ensure the correct seating on top of the implants. After radiographic verification is performed, the restorations can be placed onto the implant abutments.

CONCLUSION
The correct placement of dental abutments is imperative to achieve the proper cementation of the restorations. When multiple abutments are being placed, the smallest discrepancy in positioning of the implant abutment will prevent the restoration from fitting properly. In many cases without a jig, the treating dentist can spend valuable time figuring out the correct positioning of the dental abutments. With the use of a placement jig, these concerns can be alleviated and a much smoother placement appointment can be realized (Figure 5).

Dr. Abbo earned his dental degree from Santa Maria University in Caracas, Venezuela, in 2002. He completed a 3-year master program in prosthodontics at the University of Michigan in 2006 and was then appointed clinical lecturer for its prosthodontic department. While teaching, he practiced dentistry in a private dental practice as well as in the University Prosthodontic Clinic for a period of 2 years. He has published numerous articles in various dental journals and has lectured and conducted workshops both nationally and internationally. His topics of interest have included dental implants, all-ceramic restorations, and aesthetics. Currently, Dr. Abbo owns a private practice in North Miami Beach, Fla, has state-of-the-art technology, and is committed to excellence—providing his patients with optimal dental care in a warm and caring environment. He can be reached at bill@drabbo.com or bill_abbo@hotmail.com.

Disclosure: Dr. Abbo reports no conflict of interest.