preparing the various grooves in the bone to accommodate the blade implants. Too often the carbide bur wears out after cutting only a few grooves. The result could overheat the bone by in-creased friction causing necrosis. Sometimes severe overheating may cause an osteitis or osteomyelitis. Thus, the 700 XL carbide bur must be changed after every two, three or four grooves. It is sometimes necessary to use two new burs for one groove.

2.  The water spray should not only be directed from the hand-piece attachment itself, but an additional water spray should be held and sprayed on the bur by an assistant.

Before inserting the implant, the groove should again be sprayed with a water syringe or with saline in order to remove all debris.

3.  The bone should never be spread or compressed beyond its physiologic capacity. Bone has a viscoelastic characteristic and as long as it is not abused, it will spring back to its original shape and form.

               If, for example the groove was not made deep enough so that the bone had to spread beyond its capacity to seat the blade to its proper depth, the bone will not be capable of springing back. The results end in loosening and loss of the implant with a sloughing off and sequestra of bone forming from the original implant site. In certain areas in the same arch the bone radically differs. For example, in the anterior regions of the mandible as the bur approaches the symphysis while making a groove, the bone becomes denser and denser. The bone in this area does not have the same spring action as the remaining viscoelastic characteristics of the rest of the lower arch and that of the maxilla. Therefore, the bur must be changed more often or it can overheat the dense bone. Also, the blade must never be forced into the groove in this area since it could more easily spread the bone beyond its physiologic capacity. Since there is a limited blood supply in this dense area, recovery would be more difficult. If a bur should break and remain in the groove the easiest way to remove it would be to spin out the broken one with another bur.

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