A Histological and Radiological Study of Bone Formation around Porous Resorbable β-Tricalcium Phosphate Used as Bone Defect Filling

Abstract:

The purpose of this study was to analyze the histological, histochemical and radiological findings gained from pre-clinical in vitro and in vivo tests and from implantation of ß-tricalcium phosphate PORESORB^®-TCP (P). (P) is a bioactive, resorbable, inorganic, crystalline, non-metallic material with osseoconductive properties intended for replacement of bone tissue. The (P) granules (size 1-2mm) were implanted into the tibia of dogs for 3 and 6 months. The formation of 53% and 72% of new bone was observed after 3 and 6 months respectively.Material (P) sized 0.3-0.6 mm was used to fill in the periodontal defect and also as a carrier of growth proteins. During the study period, no undesired response to the material used was observed. The values of the plaque index showed standard hygienic conditions – the values of PlI were 0.72, 0.65 and 0.62 before treatment and 6 and 12 months after treatment, respectively.A total of 72 two-stage sinus lifts were performed in 54 patients. The autologous bone was harvested from the mandibular ramus and mixed with the (P) material sized 1-2 mm. The materials were used in a proportion ranging between 1: 1 and 1: 3. The residual allograft area was 16.21 ± 8.78 %. The connective tissue was 44.16 ± 5.85 %.This has been a retrospective review of the healing of bone defects, due to benign tumours or tumour-like lesions, using (P) material sized 1.3 mm, 0.7 mm (0.6-2 mm) as bone graft substitutes. 87 patients with bone defects (average volume 15 cm³; interval 0.4 – 144 cm³) were included. Defects with a volume up to 4 cm³ had the same successful rate of healing both for autologous bone grafts and (P). (P) sized 1.3 mm; 0.7 mm (0.6-2 mm) was successfully used in defects with volume up to 4 cm³. However, it is evident that the ratio of the size of the defect and the size of the applied granule must be kept near to 10/1 for successful treatment.