DISCUSSION.
The idea of close adaptation of the superstructure to the alveolar crest is aimed at getting an improved esthetic solution and improving the phonetic function of the patient. The patients in our study were able to function well socially and felt that the prostheses were a natural continuation of the alveolar process. Another important functional improvement is that there is no food impaction between the alveolar process and the superstructure. The difficulty with the present design of bridge construction is that it is difficult to make a visual examination of the fixtures without removing the bridge. Logically, it should be much more difficult to clean the area, but the patients did not experience difficulty. The patients performed 90% of their dental oral hygiene with rotating brushes and the rest with superfloss instruments. None of the patients have had pain from the gingival tissue. Instead, they experienced a very comfortable situation.
Visual inspection of the areas performed annually for up to six years has demonstrated gingival mucosal health. The reconstruction of the alveolar crest to a normal configuration to compensate for the loss of bone tissue with a superstructure closely adapted to the soft tissues has had a positive effect on the patients. The very low failure rate, despite difficult cases with deficient bone volume in both the mandible and the maxilla, is favorable for our method.
When measuring the marginal bone height in the radiographs, we found that marginal bone loss was more advanced in the maxilla and that even in five-year follow-up the bone reduction was almost negligible in the mandible. The bone situations in our maxillary cases consisted of very thin narrow ridges with just enough bone to perform conventional implant surgery. In many cases, threads were left exposed on the palatal side. Exposed threads could explain a more rapid marginal bone loss. Remodeling of the bone could account for some of the bone loss in these cases. However, major loss was found in just a couple of patients, indicating that perhaps systemic factors could be influential. The close adaptation of the superstructures does not mean that we create an impossible situation for the patient. However, when comparing the results in our study with longitudinal 15-year studies, the figures are compatible. The clinical and radiographic examinations support this prosthetic design. It also seems that the patients were more able to keep the closely adapted reconstructions hygienic than they were when a space was created between the alveolar crest and the superstructure (Fig. 1). Since the beginning of our study, making these superstructures it has become more routine.

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