implant. They have failed due to surgical, operative or prosthodontic procedures. I state this after 25 years of experience with every available type of implant as well as using most of the materials that have been utilized for implantology. To list some: cobalt-chrome, tantalum, various stainless steels, plastics, aluminum oxides, alloys of titanium and pure titanium. These materials have been used not only separately in an individual, but often used in combination with three or four different kinds of metal implants. Occasionally another metal such as gold for the prosthesis and amalgam fillings exist in the same mouth. Therefore, failure of implants occurs mostly from dentists with little experience and even less knowledge of the various aspects using the procedure.

In order for an implant to have an excellent chance for success I have formulated five basic rules:

1. The implant must be designed architecturally correct.

2. The operator must be able to place the properly designed implant correctly into the bone.

3. There must be enough available bone to be able to insert the implant properly into it.

4. From the moment the implant is inserted to the final cementation of the fixed prosthesis there must be careful handling of the implant as well as the hard and soft tissues. The type of impression materials during the various impression techniques must also be followed and well understood. Rubber or silicone must never be left inside the bony crypt or gingival sulcus since it can easily destroy bone. If copper bands are used then they should never be chilled while over the posts of the blades as some of the material can flow underneath the posts and around the underlying necks ruining the impression. Instead the warm compound must be lifted and placed over the implant post 5 or 6 times without chilling. This eliminates distortion and does not loosen the implant.

5. The final prosthesis must fit properly and occlude exactly and fit passively. It must not be forced over an unparalleled implant as it could move it out of its crypt.

Bone needs stimulation to carry on osteogenesis. Conversely bone will resorb for two reasons, not speaking pathologically, trauma and hypofunction. A full arch conventional denture or a free end partial re-movable prosthesis that only sits on the soft tissues cannot stimulate the bone and thus through hypofunction the bone atrophies. During this remodeling state, a venous, arterial and capillary stasis occurs causing a swelling, engorgement and edema of the blood vessels. This causes pressure to the bone beyond its physiologic capacity which ultimately leads to resorption.

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