Key Words

Platelet rich plasma [PRP], Osseous defects, Osteoinduction, Osteoconduction, Bone regeneration, Centrifugation

Introduction

Local defects in bone arising as a result of trauma or surgery are frequently restored by bone graft1,2 substitutes, preferably by autografts and allografts.

Allografts and xenografts may be toxic, chemically unstable, cause inflammatory or antigenic reaction3 . Another important property is that its microstructure can not be controlled to promote the formation of pores that can allow the migration of blood vessels and bone tissues into the material4

Platelet Rich Plasma[PRP] is r graft material for restoration of bone defects . It can be used alone or in combination with other alloplast or xenograft materials. Autogenous PRP has advantages over allografts in many aspects5 . It initiates the osteoinduction process which is mediated by growth factors present in platelets. When these platelets are present in higher number, it can produce large amount of growth factors initiating bone formation6 . Platelets can be taken from patients own blood in labs via different procedures. PRP initiates bone regeneration and healing of surrounding tissues also.

Material & Methods

This study was carried out on 25 children aged 8 to 13 years, having no acute infection. or medical compromise. The cases of peri apical cyst, peri apical pathology and bone defects after extraction were selected and grafting was done in all cases. The surgical procedure was performed to remove pathologies or tooth. 20 ml of blood was withdrawn from each patient and centrifuged at 15000 rpm for 10 minutes to separate RBCs and plasma. The plasma was recentrifuged for 15 minutes, Calcium chloride [0.5%] added and hot water bath given for 20 minutes, to achieve Platelet rich Plasma.

PRP is now collected from the top layer for packing into the defect [Fig.1]. The flap was closed and medications prescribed

Fig. 1 PRP packed in defect

The postoperative evaluation of all the patients was done at 1st, 2nd and 6th month to assess bone swelling, formation and graft rejection by Radiographic and clinical observation at recalls.

Results

After recording the clinical and radiographic data following results were tabulated :

Table I

Incidence of Swelling

1 st month follow up 2 nd month follow up 6 th month follow up
Yes % No. % No. %
Present 25 100 00 00 00 00

Swelling was observed in 1st month only.

Table II

Radiographic evidences of bone formation

1 st month follow up 2 nd month follow up 6 th month follow up
No. % YES % YES %
Present 25 100 25 100 25 100

Bone formation was observed at the end of 2nd month which is higher than the normal healing rate. Assessment of radiograph was done on the basis of radio-pacity and trabeculi pattern of bone [Fig.2]

Discussion

Bone substitutes are in great demand in the treatment of various disorders like periodontal diseases, dental periapical abscess, bone tumors, trauma and other bone defects7 . The use of autogenous bone has remained the gold standard in restoring bone defects8 , but it is not always possible to obtain enough bone or the amount of bone needed may exceed than that may be available9 .

For these reasons, biomaterials have been investigated as an alternative to autogenous bone grafts10 . Bone substitute materials are grafted to serve as a filler and scaffold to promote wound healing11 and facilitate bone formation.

The present study was done to determine the efficacy of PRP grafted into the osseous defects in pediatric patients ranging from 8-13 years . Hypothesis behind early bone formation in PRP is as a result of the effect of different growth factors, namely mitogenesis , angiogenesis, fibroblastic and osteoblastic activity, macrophage activation, maturation of bone and osteoclast mediated resorption8 are the processes which take place to initiate bone formation. Bone is formed from all aspects of bone available at site.

These results indicated that the PRP can be used as graft material in bone defects for early bone formation.

Conclusion

Bone grafts are used for treatment of various osseous defects but PRP holds the potential for bone formation similar to natural bone healing pattern in a faster way. The use of autogenous bone has remained the gold standard in restoring bone defects since long time and PRP continues the same phenomenon without any complication.

Following conclusion can be drawn that Post surgical healing with good clinical and radiographic values without adverse complication can be done by PRP.