Experimental study of the effect of autologous platelet-rich plasma on the early phases of osteoinduction by allogenic demineralized bone matrix

Influence of platelet-derived growth factor on osseous remodeling properties of a variable-thread tapered dental implant in vivo

OBJECTIVES

To evaluate the effect of platelet-derived growth factor (rhPDGF-BB) on the promotion of osteogenesis around variable-thread tapered implants in an animal model.

MATERIAL AND METHODS

Twenty-four variable-thread tapered implants were inserted in the tibia of 12 rabbits. Twelve sites received additional rhPDGF-BB released from a presoaked xenogenic bone block that was fixed supracrestally. Primary outcomes were bone-to-implant contact (BIC; in % ± SD) and percentage of medullary bone fill around the implants (PMF; in % ± SD) after 3 weeks (PDGF n = 6, no PDGF n = 6) and 6 weeks (PDGF n = 6, no PDGF n = 6).

RESULTS

Considerable crestal and medullary bone remodeling could be found around all implants. After 3 weeks, both BIC and PMF values were higher in the no PDGF group (BIC: 63% ± 10 with PDGF vs. 85% ± 5 with no PDGF; PMF: 57% ± 10 with PDGF vs. 74% ± 4 with no PDGF). After 6 weeks, the BIC difference between the two groups was less distinct (BIC: 78% ± 17 with PDGF vs. 72% ± 25 with no PDGF), whereas the PDGF group showed higher PMF values (PMF: 77% ± 5 with PDGF vs. 56% ± 10 with no PDGF).

CONCLUSIONS

The addition of rhPDGF-BB decreases early osseous crestal and medullar healing properties around dental implants. In a later phase, an increase in the cortical area as well as an increased medullar bone formation was seen. This response is likely to provide stronger secondary stability and stability in suboptimal situations involving poor-quality bone.

Enhancement of bone regeneration with the combination of platelet-rich fibrin and synthetic graft

INTRODUCTION

Platelet-rich fibrin (PRF) is a relatively new developed platelet concentrate with several benefits over platelet-rich plasma. The aim of this study was to compare healing properties of PRF and its combination with a ceramic synthetic material (graft) composed of hydroxyapatite and b-tricalcium phosphate in an animal model.

METHODS

A bone deficit was surgically created in each femoral condyle of 15 New Zealand white rabbits. In each animal, 1 limb had (a) PRF only and the other (b) PRF plus synthetic graft material randomly implanted. Experimental animals were killed 3 months postoperatively. Histological and radiological examinations were made by means of computed tomography and peripheral quantitative computed tomography.

RESULTS

Mean density of the healed bone was statistically significantly greater when synthetic material was used (P < 0.0005). Moreover, combination of PRF with the synthetic material resulted in more cortical and subcortical bone formation (P = 0.038 and P = 0.037, respectively).

CONCLUSIONS

The addition of the ceramic material significantly increased the formation of new bone, providing a better substrate for bone regeneration.

Bone regenerative medicine: classic options, novel strategies, and future directions

This review analyzes the literature of bone grafts and introduces tissue engineering as a strategy in this field of orthopedic surgery. We evaluated articles concerning bone grafts; analyzed characteristics, advantages, and limitations of the grafts; and provided explanations about bone-tissue engineering technologies. Many bone grafting materials are available to enhance bone healing and regeneration, from bone autografts to graft substitutes; they can be used alone or in combination. Autografts are the gold standard for this purpose, since they provide osteogenic cells, osteoinductive growth factors, and an osteoconductive scaffold, all essential for new bone growth. Autografts carry the limitations of morbidity at the harvesting site and limited availability. Allografts and xenografts carry the risk of disease transmission and rejection. Tissue engineering is a new and developing option that had been introduced to reduce limitations of bone grafts and improve the healing processes of the bone fractures and defects. The combined use of scaffolds, healing promoting factors, together with gene therapy, and, more recently, three-dimensional printing of tissue-engineered constructs may open new insights in the near future.

Bone regenerative medicine: classic options, novel strategies, and future directions

This review analyzes the literature of bone grafts and introduces tissue engineering as a strategy in this field of orthopedic surgery. We evaluated articles concerning bone grafts; analyzed characteristics, advantages, and limitations of the grafts; and provided explanations about bone-tissue engineering technologies. Many bone grafting materials are available to enhance bone healing and regeneration, from bone autografts to graft substitutes; they can be used alone or in combination. Autografts are the gold standard for this purpose, since they provide osteogenic cells, osteoinductive growth factors, and an osteoconductive scaffold, all essential for new bone growth. Autografts carry the limitations of morbidity at the harvesting site and limited availability. Allografts and xenografts carry the risk of disease transmission and rejection. Tissue engineering is a new and developing option that had been introduced to reduce limitations of bone grafts and improve the healing processes of the bone fractures and defects. The combined use of scaffolds, healing promoting factors, together with gene therapy, and, more recently, three-dimensional printing of tissue-engineered constructs may open new insights in the near future.