to scarify the tissue by making a number of deep accessory incisions or to bring in a tissue graft from the palate.

Through experience I have found much better and rapid healing in the maxilla than in the mandible. Pre-existing oroantral fistulas must be avoided both with the scalpel and with the implant itself. The sinus must first be irrigated thoroughly with saline or plain water, the polyps removed from its walls and sometimes a gold plate placed across the opening and sutured with surgical silk. The patient should be placed on an antibiotic. Implants must be avoided until the soft tissue healing has been completed. It is imperative that any implants to be inserted should be far enough away from the healed site in order to avoid any penetration of the bony walls of the sinus. (The pterygoid implant avoids these areas magnificently.)

Exostoses, although directly affecting a removable conventional denture since they exist in areas of the denture base such as on the lingual aspects of the posterior ridges in the mandible must be removed. With implants, however, these may remain since implants do not go into those areas.

In areas of fibrous hyperplasia it sometimes becomes necessary to remove the tissue before or during insertion of the blades, especially if it appears on the ridge crests. If hyperplasia was caused by an ill fitting denture, the denture should be relined with a soft tissue conditioner until the tissue "tones up" and possibly no surgery will be necessary.

The conservation of teeth has always been important. How-ever, teeth that might be considered to a periodontist totally unsaveable making a case hopeless for fixed restorative dentistry does by no means contraindicate implants. For example, the lower six anterior teeth may have as little as 1/10th the bone remaining around their apices. However, below these apices there is usually a tremendous amount of dense bone to insert very well supported blades. It is the bone beneath the apices of the teeth that exists between them and the underlying vital structures that concerns the implantologist.

        I used to try to save all loose teeth or periodontally involved teeth by apicoectomies, root resection, endodontic stabilizers with or without reimplantation of the teeth, removing at the same time any pockets. I do not often save them since the advent of blades.
       An entire arch or mouth of periodontally involved teeth that
are removed, once the bone has grown back, eliminates the peri-

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