Integrated Abutment Crown™ (IAC): Seating Considerations

Tissue Considerations

Soft tissue or bony interferences, particularly palatal soft tissue in the maxillary anterior along with the inappropriate direction of the seating force are potential causes preventing the proper seating of an IAC.
A periapical radiograph or reflection of a soft tissue flap may be necessary to ascertain the cause of the seating interferences.
In addition to the use of a sulcus reamer and oblique crestal relieving incisions, it may be necessary to remove a semi-lunar piece of palatal tissue to facilitate seating of some maxillary anterior IACs.

IACs must only have passive interproximal contacts. If the contacts are too tight they will prevent proper orientation, seating, and engagement of the 1.5˚ locking taper.
An orientation jig will provide initial alignment of an IAC. However, prior to its final seating, precise alignment will depend upon aesthetics and functional considerations.
Maxillary anterior IACs require meticulous attention to achieve passive interproximal contacts and proper alignment of their cleaned post with the well of the implant. Tapping an inappropriately aligned post may distort the shape of the post or well of the implant.

Use of a caliper alignment device to fabricate a seating jig will significantly facilitate and assure the appropriate alignment of the seating forces. Their use is highly recommended for maxillary anterior IAC restorations.
Tap the crown into place with a few taps, using a 250g mallet. It is imperative that the tapping force be directed in the long axis of the abutment and the implant well.
Avoid applying seating forces to maxillary anterior IACs unless the seating forces are in the long axis of the implant well. Off axis seating forces can cause deformation of the abutment post and implant well possibly resulting in non-retentive restorations.

Avoid handling of the abutment post, since any change in the contour of the post or any contamination of the post prior to its insertion can result in a non-retentive unsplinted maxillary anterior restoration.
Inappropriate use of implant placement instrumentation may distort the integrity of the implant well which may result in a non-retentive maxillary anterior restoration.
Seating of an IAC other than in the precise long axis of the abutment post and implant well (possibly because of interproximal or bony interferences) may result in the deformation of the implant well, which may result in non-retentive unsplinted maxillary anterior restorations.
To achieve a more intimate metal contact and retention between the abutment post and the implant well, slightly rotate a meticulously cleaned abutment post back and forth in the clean and dry implant well prior to applying multiple gentle seating taps in the precise long axis of the implant well and abutment post.