[Autogenous bone versus beta-tricalcium phosphate graft alone for bilateral sinus elevations (2-3D CT, histologic and histomorphometric evaluations)].

INTRODUCTION

When the maxilla is edentulous and the alveolar process is extensively absorbed, a dental root can be implanted only after the implantation of bone or a bone-substitute. Only in this way can the subjective and objective negative features associated with a removable prosthesis be avoided. Many forms of bone-substitutes are known. Freely taken bone from the patient generally serves as the gold standard for the classification of bone-substitutes.

AIMS: The aim of our work was to compare two materials (the patient's own bone and beta-tricalcium phosphate) in the same patient.

METHODS

Ten patients were selected who for some reason did not want or could not wear a removable prosthesis. The maxilla was so atrophied that bone or bone-substitute implantation was necessary before the dental root could be implanted. The maxilla had to be elevated from inside (sinus elevation) and thickened from outside (onlay-plasty). Bone was taken in the usual manner from the hipbone. For the internal elevation, such autogenous bone was utilized on one side, and beta-tricalcium phosphate granulate on the other. The formation of new bone and the rate of bone formation were followed by clinical methods and by radiological, histological, and histomorphometric examinations.

RESULTS

The implantation succeeded clinically in all ten patients: one year later they all received a fixed bridge. The radiological and histological examinations demonstrated good bone formation on both sides. As concerns the rate of formation of new bone, there was practically no difference after the implantation of autogenous bone or beta-tricalcium phosphate.

CONCLUSIONS

This study has therefore provided further evidence that, when certain bone deficiencies are to be eliminated, the unpleasant phenomena accompanying the removal of the patient's own bone can be avoided through the use of new synthetic materials. Accordingly, when comparing the present results with the findings of other authors, beta-tricalcium phosphate may be considered a good graft material even without autogenous bone.