The aim of the present study is to evaluate the regenerative capacity of PRF© with Bio-Oss® particulate heterologous bone grafts mixed with 50% of cortical and medullary grafts and 50% of pure-phase beta-tricalcium phosphate (ß-TCP) and SintOss, compared with the use of Bio-Oss® mixed with 50% of cortical and medullary grafts and 50% of ß-TCP and SintOss, in the treatment of maxillary atrophy with Tatum’s sinus lift technique.

Methods
32 patients aged between 42 and 75 years were selected, 12 females and 20 males. 37 sinus lift surgeries were performed (with placement of 84 fixtures), which can be classified into two groups according to the graft material used: in the study group (21 patients with placement of 59 fixtures) the combination of PRF / Bio-Oss (equally mixed with cortical and medullary grafts and pure ß-TCP) and SintOss was used, while in the control group (11 patients and with placement of 25 fixtures) only Bio-Oss and SintOss (ß -TCP) were used.

Results
Healing was assessed by clinical and radiological examinations (OPT x-ray, CT, DentaScan) . The 12-month X-ray control revealed the presence of well integrated new bone tissue, as well as an intimate contact of implants with the newly formed bone.
The histological report showed that the bone tissue specimens taken from the site treated with the association PRF/ Bio-Oss and ß-TCP after only 4 months consisted of lamellar bone tissue with an intensely-eosinophilic bone matrix to be ascribed to the newly-formed bone tissue; osteocytes were disposed horizontally. The stroma was relaxed and richly vascularized.

Specimens from the control group taken after 8 months fragments were constituted by trabeculae of lamellar bone tissue with inhabited osteocyte lacunae, immersed in a dense poorly-cellular fibrous stroma, in which are included fragments of lamellar bone with empty osteocyte lacunae as a result of the granules of Bio-Oss not yet integrated into the bone matrix, and with an intensely-eosinophilic bone matrix

Histomorphometric analysis showed the presence of mineralized trabecular bone in both groups. In the study group there was the presence of osteocytes, osteoblasts and osteoyd materials, in small quantity but higher than specimens taken from the group control.

Conclusion
The use of Bio-Oss mixed with ß-TCP and associated with the growth factors of PRF reduced the healing time and resulted in a faster bone regeneration, which allowed to place implants already after 4 months. Bovine bone grafts (equally mixed with cortical and medullary grafts and pure ß-TCP) and PRF allowed to place fixtures in sinus lift with basal bone measuring less than 5 mm. Moreover, its gelatinous consistency favors clot stability and the membranous shape allows to create a natural “barrier effect” on the bone breaches that were opened in the surgical areas, and it also improves tissue healing. Clinical and radiographic controls were performed every 12 months for 48 months and DentaScan CT every 24 months. Only one fixture failed out of 59 placed in the study group.

Authors
INCHINGOLO Francesco, IMPEDOVO ANNA LUCIA MARIA, INGROSSO Marianna Pia, INGROSSO Angela Maria, PIGNATARO Chiara, SCHINCO Fabio, INCHINGOLO Alessio Danilo, MARRELLI Massimo, DEL CORSO Marco, INCHINGOLO Angelo Michele, TATULLO Marco, MALCANGI Giuseppina, PADUANELLI Gregorio, MURA Stefano, MUOLLO Ferdinando, DIPALMA Gianna.