Platelet Rich Plasma to Facilitate Wound Healing Following Tooth Extraction
Following tooth removal bone formation normally takes 16 weeks and may result in less than adequate volume for the necessary reconstruction. Platelet rich plasma (PRP) has been promoted as an effective method for improving bone formation. Its use is often expensive, time consuming, or not clinically convenient for the patient and/or clinician. This study examines a simple method for obtaining a “Buffy Coat”-PRP (BC-PRP) and its effect on bone healing following the removal of bilateral mandibular 3rd molars. Subtraction digital radiography and CT scan analysis were used to track changes in radiographic density at PRP treated sites in comparison to ipsilateral non-PRP treated sites. PRP treated sites demonstrated early and significant increased radiographic density over baseline measurements following tooth removal. The greatest benefit of PRP is during the initial 2-week postoperative healing time period (P < .001). During weeks 3 though 12, BC-PRP treatment resulted in significant (P < .0001) increases in bone density compared to control, but there was no significant interaction between time and treatment (P > .05). For the entire time period (0–25 weeks) PRP treatment was significant (P < .0001) and time was significant (P < .0001) but there was no significant interaction (P > .05) between the effect of PRP treatment and time. It required 6 weeks for control extraction sites to reach comparable bone density that PRP treated sites achieved at week 1. Postoperative pain, bleeding, and numbness were not significantly affected by BC-PRP application. Results suggest that this simple technique may be of value to clinicians performing oral surgery by facilitating bone regeneration following tooth extraction.Abstract
Placement of custom label for consistent retrieval of Buffy Coat platelet rich plasma (PRP). The dotted line is placed at the interface of the red blood cells and the platelet poor plasma (PPP)—between these 2 layers is the PRP layer. The PPP is removed down to the top solid line. The PRP layer is between the top solid line and the bottom solid line.
Anticoagulated whole blood after centrifugation. Close-up of pelleted anticoagulated whole blood separated into the 3 layers. Note the placement of the label on the outside of the tube is dictated by matching the dotted line to the plasma/cell pellet interface. PPP indicates platelet poor plasma; PRP, platelet rich plasma; RBC, red blood cell.
Percent radiographic density change of surgical ±platelet rich plasma (PRP) treatment compared to control radiograph taken immediately following tooth removal. All 6 patients are represented in this graph with each point representing the mean ±SEM percent change in bone density for each week for either the PRP-treated site or control site. Comparisons between treated and untreated sites were made using a two-tailed paired t test. Significance was defined as P < .05, where a = P < .01; b = P > .05 for individual time points. For the span of time-periods, a two-way ANOVA was performed and significance was defined as P < .05. For the time period 0 to 2 weeks PRP treatment was significant (P < .0001); time was not significant (P > .05); but there was a significant interaction (P < .001) between the benefits of PRP treatment and time, therefore the beneficial effects of the PRP-treatment and time were related for the initial 2 week postoperative healing time period. For weeks 3 though 12 treatment was significant (P < .0001), but time was not (P > .05) and there was no significant interaction between time and treatment (P > .05). For the time period 0 to 25 weeks PRP treatment was significant (P < .0001); time was significant (P < .0001); but there was not a significant interaction (P > .05) between the benefits of PRP treatment and time, therefore the effect of the PRP treatment was independent of time for the entire 25 week time period. The marked difference in bone density during the initial 2-week postoperative period denotes the accelerated bone formation of the site that received the PRP treatment. The early increase in bone density at the PRP treated sites contrasts with the control sites that have a decrease in bone density indicating bone loss during the same time period. Note that the control sites took 6 weeks to reach the same degree of bone density that the PRP-treated sites reached at week 1.
Computerized tomogram scan analysis: (a) Percent bone fill. Where a = P < .05 revealed that platelet rich plasma (PRP) treatment significantly enhanced the percent bone fill when compared to non-PRP-treated sites (control). For b = P < .01 Time elapsed since tooth removal was significant. (b) Newly formed bone density (NFBD). NFBD with PRP treatment was not significant (P > .05) in comparison to the control sites. Time elapsed was not a significant (P > .05) factor for NFBD. (c) Total formed bone density (TFBD). TFBD with PRP treatment was not significant (P > .05) in comparison to the control sites. Time elapsed did have a significant effect (P < .0001) on TFBD. Graphs represent 3 patients over the 3 time points and analyzed by two-way ANOVA where significance was defined as P < .05.
Effect of NSAIDs on bone formation. The use of NSAIDs blocks the formation of prostaglandin E2 (PGE2) initiated by the release of arachidonic acid. The lack of PGE2 formation associated with the inflammatory response interferes with bone formation. The use of platelet rich plasma (PRP), which contains white blood cells (WBCs) that release interleukin-1α (IL-1α) and platelets, which release IL-1α, transforming growth factor β1 (TGF-β1), platelet-derived growth factor BB (PDGF-BB), vascular endothelial growth factor (VEGF), and osteoprotegrin (OPG), may potentially mitigate the adverse effects that NSAID use has on bone development.
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