its entire depth, even in porous bone, to facilitate insertion in difficult seating situations.

The implant is tried in the site, and the post's angulation compared with that of the teeth to be prepared and included in the restoration. The neck must be bent to parallel the post (12) with these teeth, not necessarily perpendicular (13) to the arch. If the socket is angled across the dental arch line, the neck must be twisted (14) to follow the arch (15).

The single-headed inserting instrument is used with the narrow, single-tooth implant. Because the post is parallel to prepared teeth in most short-span situations, it is not usually acutely angled. There-fore, it is relatively easy to direct the taps along the axis of the socket with the single-headed inserting instrument.

As normal operative precaution, gentle taps are appropriate. A supporting finger safeguards the labial plate, and both fingers should brace a narrow ridge or one in which the implant will closely approach either plate.

The implant is correctly seated when all faces of the bottom of the post meet the crest. Countersinking is usually unnecessary be-cause the implant post is aligned with the teeth, and thus the axial inclination of the ridge.

However, in a few cases only the lingual face of the post may touch the crest, and a notch should be made in the lingual side of the crest to correctly seat the post. As the operator gains experience, he will be able to predict the necessity for countersinking and make the necessary socket adjustment with the implant in or out of the mouth, prior to tapping.

Caution: If the implant remains in its socket during countersinking, copious amounts of water must be used to keep the bone cool and prevent heat transfer from the metal implant.

The single-tooth implant is the only bladevent design that should be immediately stabilized after insertion. The type of support will depend upon the condition of neighboring teeth.

Midline Implant

Usually the ridge is sufficiently wide and tall at the midline to accept a bladevent. The bone is extremely dense in this area requiring the operator to frequently change the cutting burs. The

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