The implant is bent to follow the curve of the groove and inserted with manual pressure to determine the proper angulation of the posts. The implant is withdrawn, post adjustments made, and reinserted in a cleansed socket.

The implant is finally seated by tapping it to the correct depth. Care must be taken to keep the shoulders level with the occlusal plane. The deeper end is tapped first (14), with a finger on the shallow end's post to prevent it from popping up.

Caution: Special attention should be paid when tapping the shallower end to avoid knocking the implant into the sinus.

An irregularly flared sinus may have dropped so low that there is insufficient bone under it to extend a bladevent's shoulder. However, it may be possible to place a special blade on either or both sides of the flared area, depending upon the overall shape of the sinus.

The same design may be used posteriorly (15) or anteriorly (16) by reversing it. This special design also comes in a double-posted variation (17), the two posts sharing the pressure that would otherwise be brought to bear on one post. However, the double-posted variation is for anterior use only. Posteriorly, the more distal post and its restoration could interfere with the ascending ramus.

When the post sinus portion of the ridge resorbs upward from the occlusal plane (18), the bladevent — if correctly inserted — is angled (19) into bone. Its post must be bent forward (20) so that it will be parallel to the other abutments (21), and perpendicular to the occlusal plane. Countersinking (22) will probably be necessary under the mesial face of the post.

Caution: The small sinus-circumventing bladevent is one of the few that should rarely be altered. It has been carefully balanced in design to serve in precarious situations. Choosing another site or type of implant is preferable to reducing the body of this particular bladevent.

Problem Ridge:

Maxillary Tuberosity Bladevent

When less than 7 mm of bone separates the sinus from the crest, the maxillary tuberosity (1) may serve as the posterior blade-vent site — if there is adequate bone behind the sinus and if the

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