December 1, 2006
by Astley E. Smith, B.Sc.(Chem), M.Sc.(Biochem), DMD
I wish to bring to your attention that a paper written by myself has been published in the Journal of Oral Health, May 2006, page 79-88. It is also available on the Journal’s website www.oralhealthjournal.com. The title is “Procedure for Autologous Thrombin Activation of Platelets in Platelet Rich Plasma (PRP).” This procedure allows a dentist or physician to use the patient’s pure autologous thrombin to activate the patient’s concentrated platelets to release proteins (growth factors) which stimulate, accelerate and enhance the body’s natural healing processes in localized surgical sites.
When PRP gel is mixed with autogenous bone or any bone substitute material, the handling characteristics are excellent for all bone grafting procedures, and patient’s post operative discomfort and swelling are minimized. Since 1990 it has been shown in Europe and North America that PRP enhances both hard and soft tissue wound healing primarily in the areas of angiogenesis (in growth of new blood vessels from host vessels) and mitogenesis of mesenchymal stem cells, osteoprogenitor and endothelial cells. The effectiveness of highly concentrated recombinant platelet derived growth factor and bone morphogenetic protein is a validation of the potential effectiveness of PRP when properly produced and activated. However, the two above mentioned recombinant growth factors are not autologous.
When xenogeneic bovine thrombin became unavailable in Canada in January 2004, an alternative had to be found for platelet activation. The development of this procedure for platelet activation with pure autologous human thrombin (as published) is that needed alternative. In this procedure the pure autologous thrombin is obtained from the patient’s serum at the same time the PRP is produced. The thrombin obtained will activate PRP produced by any manual or automated centrifuge. Although this procedure was developed for Canadian dentists and physicians, it will have global applications particularly in places where there is concern about the development of disease transition and immune response.
The procedure for the production and activation of PRP with pure autologous human thrombin is technique sensitive and therefore appropriate training is advised. A PRP Certification Seminar involving manual and automated centrifuges is offered by the author. The seminar covers phlebotomy and the applications of PRP to bone grafting and implantology using pure autologous human thrombin for platelet activation.
The different results that a minority of researchers are getting when PRP is used with bone grafting is probably highly related to technique sensitivity. In order to help remedy this situation I am proposing the following guidelines in the form of twelve questions which should be thoroughly reviewed and answered before PRP is used with bone grafting.
For further information, contact: Dr. Astley E. Smith, Belmont Dental Centre, New Westminster, Greater Vancouver, BC, Canada. V3L 3C2. Phone: (604) 521-6313, Fax: (604) 521-6322 or e-mail: firstname.lastname@example.org
12 QUESTIONS TO CONSIDER WHEN USING PRP WITH BONE GRAFTING
1. Is the patient hematologically compromised?(No)
* A PTT and PT (INR) outside normal range.
* Clotting factor deficiency.
* Clotting factor inhibition.
* Taking anticoagulants.
2. Does your procedure produce viable platelets?(Yes)
3. Is your PRP produced under maximally sterile conditions?(Yes)
4. Can the platelets be activated in vitro?(Yes)
5. Is your bone grafting material thoroughly mixed into the PRP before activation?(Yes)
6. Does your bone grafting material contain a percentage of autogenous bone?(Yes)
7. When increments of PRP gel-bone material are taken, is the PRP gel separated from the bone material? (No)
8. Do the PRP gel with growth factors and bone grafting material have access to host existing vascularity? (Yes)
9. Is there adequate decortication and removal of all soft tissue from hard tissue recipient site?(Yes)
10. Is the PRP gel – bone graft material adequately covered with a cellocclusive resorbable membrane barrier? (Yes)
11. Is there tentionless and complete primary closure accompanied by sealing of surgical incision line and suture entry points? (Yes)
12. Is there an absence of micromovement and pressure irritation?(Yes)
(If any answer is different than that suggested, then appropriate correction should be made.)