A prospective multicenter randomized clinical trial of autogenous bone versus beta-tricalcium phosphate graft alone for bilateral sinus elevation: histologic and histomorphometric evaluation.

PURPOSE: Two different graft materials, beta-tricalcium phosphate (Cerasorb) and autogenous bone, were used in the same patient. The objective was to determine whether donor site morbidity could be avoided by using pure-phase beta-tricalcium phosphate (Cerasorb). MATERIALS AND METHODS: Bilateral sinus grafting was performed on 20 selected patients; Cerasorb was used on the experimental side, and autogenous bone was used on the control side. In each patient, one side was randomly designated the experimental side. In 10 of the 20 patients, the maxilla reconstruction included sinus grafting and onlay bone grafting. Implants were placed 6 months after the procedure. In addition to routine panoramic radiographs, in 10 of the 20 patients, 2- and 3-dimensional computerized tomographic examinations were performed pre- and postoperatively and after implantation. Eighty bone biopsy specimens were taken at the time of implant placement. RESULTS: Histologically and histomorphometrically, there was no significant difference between the experimental and control grafts in terms of the quantity and rate of ossification. For each histologic sample, the total surface area, the surface area that consisted of bone, and the surface area that consisted of graft material were measured in mm2, and bone and graft material were analyzed as percentages of the total. The mean percentage bone areas were 36.47% +/- 6.9% and 38.34% +/- 7.4%, respectively; the difference was not significant (P = .25). DISCUSSION AND CONCLUSION: Comparisons with other studies reveal that beta-tricalcium phosphate (Cerasorb) is a satisfactory graft material, even without autogenous bone.

[Histologic and histomorphometric study of bone regeneration induced by beta-tricalcium phosphate (multicenter study)]. / A beta-trikalcium-foszfát graft csontregeneráló hatásának hisztológiai és hisztomorfometriai vizsgálata (multicentrikus tanulmány).

INTRODUCTION: Autogenous bone graft insertion can effectively enhance the regeneration of the debilitated bone. However, bone graft can be harvested only by a second surgery, which is inconvenient for the patient and raises the possibility of many complications. AIMS: The effect of an alloplastic bone-replacing material, beta-tricalcium phosphate and that of the autogenous bone graft were compared. The studies were performed on patients deriving from four European centers. METHODS: In 20 edentulous patients, the alveolar ridge was extremely atrophied, so fixation of the denture was impossible. The base of the maxillary sinus was surgically elevated bilaterally by insertion of Cerasorb (beta-tricalcium phosphate) (experimental side) and by autogenous bone graft (control side). After surgery the recovery was controlled clinically and radiologically. After 6 months bone cylinders were excised from the grafted areas and implants were inserted into their place. 80 bone samples were embedded into resin, and the osteointegration of the grafts was studied histologically. The new bone density was measured by histomorphometry. RESULTS: Beta-tricalcium phosphate proved to be an effective bone replacing material with osteoconductivity, and was capable of gradual disintegration, providing space to the regenerating bone. The new bone density was similar on both sides without significant differences. CONCLUSIONS: After 6 months, insertion of the beta-tricalcium phosphate graft resulted in formation of stable bony bed apt to anchor of dental implants.

Repair of bony defect with combination biomaterials.

BACKGROUND: Numerous possibilities are available for the reconstruction of facial bone defects. The materials used to fill such defects must satisfy various requirements. One of the most important is that they must undergo transformation into autologous bone tissue in the process of remodeling. AIM: A report is given of the long-term results of augmentations of large bone defects performed with different bone-substitute materials in two patients. PATIENTS AND METHODS: In one case, augmentation was carried out with beta-tricalcium phosphate after the removal of a fibromyxoma. In the second case, three large cystic lesions in the mandible of a patient with Gorlin-Goltz syndrome were filled with beta-tricalcium phosphate, with a mixture of beta-tricalcium phosphate and platelet concentrate, or with hydroxyapatite of algal origin. The process of ossification was checked at 6-month intervals by means of clinical, radiologic (orthopantomograms and two-dimensional and three-dimensional computer tomograms), and histologic methods. RESULTS: At 1 year after the intervention, the site of the augmentation was in all cases occupied by hard tissue of good quality. With the given imaging procedures, it was difficult to distinguish between the original bone and the region filled with bone-substitute material. The three-dimensional computer tomogram images indicated that the contours and quality of the new bone corresponded with the physiologic and anatomical conditions. The histologic examinations show the remodeling of the bone-substitute materials. DISCUSSION: The bone-substitute materials applied in these cases fully satisfied the demands of transformation into bone (remodeling). The speed of remodeling seemed to be the fastest when the mixture of beta-tricalcium phosphate and platelet concentrate was used.

[Correction of maxillary atrophy with onlay-plasty]. / Maxilla atrophia korrekciója onlay plasztikával.

Following tooth loss, augmentation of the extensively atrophized alveolar ridge of the maxilla may be necessary, in order to restore the masticatory function by the replacement of teeth anchored on implants. A number of bone augmentation methods are available for the acceptance of implants. The aim of the presented report is to summarize our experience relating to the use of free monocortical bone grafts originating from the hip (spina iliaca anterior superior) for purposes of onlay-plasty.

[Gardner syndrome. Case reports]. / Gardner-szindróma. Esetismertetés.

The authors discuss 3 cases of Gardner-syndrome, outlining malignized large intestine polyposis, multiplex osteomas and the different skin tumours as the main features. The earliest symptoms suspecting the clinical picture are usually dental and/or mandibular lesions and draw the attention to the highly malignant polyposis.

[Autogenous bone versus beta-tricalcium phosphate graft alone for bilateral sinus elevations (2-3D CT, histologic and histomorphometric evaluations)]. / Autológ csont és beta-trikalcium-foszfát alkalmazásának összehasonlító vizsgálata kétoldali sinuselevatio kapcsán (2-3D CT, hisztológiai-hisztomorfometriai kiértékelés).

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.