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Experts Corner
6 (
1
); 5-11
doi:
10.4103/2321-1407.173725

The development of submucosal injection of platelet rich plasma for accelerating orthodontic tooth movement and preserving pressure side alveolar bone

Department of Craniofacial Orthodontics, Craniofacial Research Center, Chang Gung memorial Hospital, Graduate Institute of Craniofacial Medicine, Chang Gung University, Taoyuan, Taiwan
Address for Correspondence: Dr. Eric J. W. Liou, 6F 199 Tung Hwa North Road, Taipei, 105, Taiwan. E-mail: lioueric@ms19.hinet.net
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How to cite this article: Liou EJ. The development of submucosal injection of platelet rich plasma for accelerating orthodontic tooth movement and preserving pressure side alveolar bone. APOS Trends Orthod 2016;6:5-11.

Abstract

Although the surgical-assisted accelerated orthodontic tooth movement has been proved to be the most effective one currently, its disadvantages are it is a bone surgery, and it causes loss of alveolar bone that undermines the periodontal support of the target teeth. The submucosal injection of platelet rich plasma (PRP) is a technique developed for accelerating orthodontic tooth movement by simulating the effects of bone insult without surgery and loss of alveolar bone. We have revealed clinically that submucosal injection of PRP accelerated the mandibular or maxillary alignment 1.7 folds faster in average, and the acceleration was dose-dependent when the PRP fold (platelet count in PRP/platelet count in blood) was <12.5. The optimal PRP fold for a more than 2-fold acceleration of orthodontic alignment ranged from 9.5 to 12.5 folds. On the other hand, the injection of PRP on the pressure side of en masse anterior retraction decreased 71–77% of alveolar bone loss, and this was dose-dependent. The pressure side of en masse anterior retraction had no alveolar bone loss when the PRP fold was higher than 11.0. In conclusion, the optimal PRP fold for the best performance in acceleration of orthodontic tooth movement and preservation of the pressure side alveolar bone is 11.0–12.5.

Keywords

Bone
orthodontic tooth movement
platelet rich plasma

INTRODUCTION

Several noninvasive or invasive techniques have been proposed clinically or experimentally for accelerating orthodontic tooth movement. The noninvasive techniques include the biomechanical approach such as the self-ligation brackets,[1-6] the physiological approach such as the direct electric current stimulation,[7-9] low dose laser therapy,[10-17] vibration,[18-22] or photobiomodulation,[23,24] and the pharmacological approach such as the injection of prostaglandin[25-27] or relaxin.[28-32]

Vibration or photobiomodulation is among the latest noninvasive developments that could be the most feasible and practical methods for accelerating orthodontic tooth movement, but they still need more experimental and clinical studies to prove their clinical effectiveness.[33,34] Currently, the surgical-assisted approaches have been proved experimentally and clinically to be the most effective technique in accelerating orthodontic tooth movement.[35] These invasive techniques include the rapid canine retraction through distraction of periodontal ligament,[36-40] rapid canine retraction through distraction of dentoalveolus,[41-43] periodontally accelerated osteogenic orthodontics (PAOO),[44,45] corticision,[46] orthognathic surgery,[47] piezocision,[48,49] piezopuncture,[50] and micro-osteoperforation.[51] In comparison to the noninvasive approaches, they all have surgical insults to the bone that trigger a higher osteoclastic activity, resorption of the alveolar bone, decrease of the alveolar bone density, and loss of alveolar bone of the target teeth.[44-51] Their disadvantages are the surgery is not friendly to both of the patients and orthodontists, and the loss of alveolar bone that undermines the periodontal support of the target teeth.

It is, therefore, the PAOO included the bone allograft materials to expand the alveolar bone volume to compensate the extensive loss of alveolar bone after the corticotomy, and the other surgical-assisted techniques tried to reduce the surgery from a radical and extensive surgical insult toward a conservative and limited surgical insult. This could be elucidated sequentially by the change of surgical technique of bone insult from an extensive insult of bone through flap surgery in PAOO to a flapless and moderate insult of bone in corticision or piezocision, and then toward a minimal insult of bone in piezopuncture or micro-osteoperforation.

However, the effect of a minimal insult is not equal to that of an extensive insult. It has been revealed experimentally that the intensity and extensity of accelerating tooth movement depend on the intensity and extensity of the surgical insult.[52] The bigger the intensity and extensity the surgical insult the higher the intensity and extensity of the acceleration. In other words, a minimal insult of bone might not be able to trigger a strong and long lasting effect on accelerating orthodontic tooth movement. To simulate the effects of surgical insult without surgery, the local injection of cytokines or hormone could be a substitute for the surgical insults,[25-27] but it is not practical clinically due to its systemic effects and the need of frequent injections. Injection of autologous platelet rich plasma (PRP) could be a better substitute for bone surgery.

THE PLATELET RICH PLASMA

Platelets are one of the initiators both in the soft and hard tissue wound healing processes. Platelets contain growth factors such as the platelet-derived growth factor, transforming growth factor, endothelium growth factor, and the others. These growth factors are critical in the regulation and stimulation of the wound healing process, and they play an important role in regulating cellular processes such as mitogenesis, chemotaxis, differentiation, and metabolism.[53] Peripheral blood contains 94% of red blood cells (RBCs), 6% of platelets, and <1% of white blood cells (WBCs), while PRP contains 5% of RBCs, 1% of WBC, and 94% of platelets. PRP has been applied in dentistry for its capability of enhancing osseointegration of a dental implant and augmentation of alveolar bone height in maxillary sinus lift.[54-60]

In contrast to the other medical professions, the PRP in dentistry is always prepared by mixing with calcium chloride (CaCl2) and thrombin to coagulate the platelets into a gel form and activate the containing growth factors before being applied to the region of interest through a full thickness flap operation. The CaCl2 and thrombin initiate a burst release and activation of all the growth factors of PRP all at once. It is, therefore, the duration of action of PRP is short. On the other hand, the flap surgery is invasive in nature and causes the regional acceleratory phenomenon that induces a severe alveolar bone resorption and, therefore, might diminish some of the osteogenic effects of PRP. However, due to its gel form, flap operation, and short duration of action, this preparation for PRP is not suitable for orthodontic purposes.

A suitable PRP for orthodontic purposes should be injectable and has a long lasting effect. To develop an injectable PRP with a prolong effect on the target tissue, a simple approach is to prepare the PRP without mixing with CaCl2 and thrombin, so that it could be maintained in a liquid form and be injectable.

THE PREPARATION OF PLATELET RICH PLASMA FOR ORTHODONTIC PURPOSES

The autologous PRP should be prepared under aseptic processing procedures [Figure 1].

Figure 1: The preparation of platelet rich plasma. (1a-c): The blood sample is first centrifuged under 1000 rpm for 12 min and separated into the red blood cells at the bottom, the buffy coat (platelets) in the middle, and the platelet poor plasma at the top. (2a-c): The buffy coat and platelet poor plasma are pipetted and collected with care, and centrifuged again under 3000 rpm for 8 min. (3a-c): After the second centrifugation, the platelet poor plasma is removed until 4 ml remained and then the remaining platelet poor plasma is mixed with the buffy coat to become platelet rich plasma.

  • A volume of 60 ml of whole blood is drawn from the medial cubital vein of a patient using three 30 ml syringes that each contained 3 ml of 10% sodium citrate solution as an anticoagulant. Heparin is not recommended for using as the anticoagulant due to its systemic effects and inducing alveolar bone resorption. One ml of the blood is used for checking the platelet counts.

  • The remaining 59 ml of whole blood is first centrifuged under 1000 rpm for 12 min at room temperature. The blood is then separated into its 3 basic components as the RBCs at the bottom, the buffy coat (platelets) in the middle, and the platelet poor plasma (PPP) at the top.

  • The RBCs is discarded, and the remaining buffy coat and PPP are collected and centrifuged again under 3000 rpm for 8 min. After the second centrifugation, the PPP is removed until 4 ml remained and then the remaining PPP is mixed with the buffy coat to become PRP. One ml of the PRP is analyzed for its platelet count.

Under such a preparation, the PRP contains anticoagulant, high concentration of platelets, and a few of RBCs and WBCs, and it has to be injected shortly after its preparation.

THE SUBMUCOSAL INJECTION OF PLATELET RICH PLASMA FOR ORTHODONTIC PURPOSES

The PRP together with the containing anticoagulant is injected submucosally. Due to the presence of anticoagulant, we surmised that after injection of PRP, only part of the platelets adhere and aggregate little by little on the surfaces of collagen fibers, the intrinsic and extrinsic pathways of hemostasis initiate to generate thrombin gradually, platelet clots lay down little by little above the periosteum, and then the growth factors release and infiltrate little by little into the periosteum and alveolar bone. The procedures of injection are summarized as follows [Figure 2]:

Figure 2: The platelet rich plasma is injected through the attached gingivae into oral mucosa to avoid leakage using a 27-gauge dental needle. (a): The submucosal injection of platelet rich plasma for the anterior teeth. (b): The submucosal injection of platelet rich plasma for the posterior teeth.

  • Before the injection of PRP, local anesthesia (Xylocaine) should be injected at the target sites for the pain control.

  • For each target site, 0.7 ml of PRP could be injected. It is better to inject through the attached gingivae into the oral mucosa using a 27-gauge dental needle to avoid leakage of the PRP.

  • It is a submucosal injection rather than a sub-periosteal injection. It is just similar to the injection of local anesthesia, and it has no certain injection pattern.

  • Acetaminophen (500 mg) could be prescribed for the postinjection pain control. Nonsteroidal anti-inflammatory drug will neutralize the effects PRP and is not appropriated for the postinjection pain control.

Eighty-five percent of the patients reported 6–12 h of acceptable postinjection discomfort including intraoral mucosal swelling, itching sensation and mild to moderate pain, but 15% of the patients reported severe pain. The intensity of postinjection discomfort varies with the concentration of PRP. It has been observed clinically that the higher the concentration of PRP the more the postinjection discomfort.

THE CLINICAL APPLICATIONS FOR PLATELET RICH PLASMA SUBMUCOSAL INJECTION

The injection of PRP could be applied for accelerating orthodontic tooth alignment and leveling in anterior crowding [Figure 3], and space closure in en masse anterior retraction [Figure 3] or molar protraction [Figure 4]. It could also be used for preserving the pressure side alveolar bone of en masse anterior retraction.

Figure 3: The platelet rich plasma application for accelerating the alignment of anterior crowding and space closure in a case treated with upper and lower premolar extraction. (1a-e): The first platelet rich plasma injection in the upper and lower anterior teeth. (2a-e): 3 months after the first platelet rich plasma injection. (3a-e): 6 months after the first platelet rich plasma application and the second boost of platelet rich plasma injection. (4a-e): The extraction space was closed 3 months after the second boost of platelet rich plasma injection.
Figure 4: The platelet rich plasma application for upper and lower molars protraction with temporary anchorage devices. (1a-e): The first application of platelet rich plasma at the #36, 46, and #16. (2a-e): The upper space was closed 6 months after the first platelet rich plasma injection, and the second platelet rich plasma was injected for the further space closure in the lower. (3a-e): The lower space was closed 2 months after the second injection of platelet rich plasma.

  • The target sites of injection are the labial and lingual/palatal sides of the anterior teeth when the purpose of injection is to accelerate the alignment and leveling.

  • The target site is the lingual/palatal side of anterior teeth when the purpose is to accelerate anterior retraction or to preserve the pressure side alveolar bone.

  • The target sites could be the buccal, lingual/palatal, and mesial sides of the posterior teeth when the purpose is to accelerate the protraction of posterior teeth or preserve the alveolar bone of the protracted posterior teeth.

THE DOSAGE AND EFFECTS OF SUBMUCOSAL INJECTION OF PLATELET RICH PLASMA

A single injection of PRP lasts for 5–6 months clinically. It has been observed clinically that the fastest rate of acceleration is during the second to fourth month after the injection. The applied regimen for different purposes is summarized:

  • Single injection of PRP in the beginning of treatment for the purpose of alignment and leveling.

  • One injection of PRP in the beginning and another boost of injection 6 months after the first injection for the purpose of anterior retraction.

  • One injection of PRP in the beginning and another boost of injection 6 months after the first injection for the purpose of protraction of posterior teeth.

Our clinical data revealed that the submucosal injection of PRP accelerated orthodontic tooth alignment and decreased the alveolar bone loss on the pressure side of orthodontic tooth movement. The injection of PRP accelerated the mandibular or maxillary anterior teeth alignment 1.7 folds in average (range from 1.3 to 2.1 folds), and the acceleration was dose-dependent when the PRP fold (platelet count in PRP/platelet count in blood) was <12.5. The optimal PRP fold for a more than 2-fold of acceleration of orthodontic alignment was found to be 9.5 to 12.5 folds.

On the other hand, the submucosal injection of PRP in the pressure side of en masse anterior retraction decreased 71–77% of alveolar bone loss, and this was PRP dose-dependent. The pressure side was found having no alveolar bone loss when the PRP fold was higher than 11.0.

In summary, the optimal PRP fold for a higher than 2-fold acceleration of orthodontic tooth movement and no pressure side alveolar bone loss is 11.0–12.5.

THE PREPARATION OF OPTIMAL PLATELET RICH PLASMA DOSAGE

The easiest way to prepare an 11.0–12.5 folds of PRP is to dilute a known high concentration PRP with certain amount of PPP. The high concentration PRP could be prepared by removing most of the PPP without disturbing the buffy coat at the bottom after the second centrifuge. For example, we could prepare 1.0 ml of 22 folds of high concentration PRP and then dilute with 1.0 ml of PPP to obtain 2.0 ml of 11.0 folds of PRP.

CONCLUSIONS

The submucosal injection of PRP is a clinically feasible and effective technique to accelerate orthodontic tooth movement and at the same time, preserve the alveolar bone on the pressure side of orthodontic tooth movement, and the optimal dose of PRP for the best clinical performance is 11.0–12.5 folds.

Financial support and sponsorship

This report was granted by the Taiwan National Health Research Institute (NHRI-EX102-10250E), and the Ministry of Science and Technology of Taiwan (NSC-100-2314-B-182-058).

Conflicts of interest

There are no conflicts of interest.

References

  1. , , . Self-ligating vs conventional brackets in the treatment of mandibular crowding: A prospective clinical trial of treatment duration and dental effects. Am J Orthod Dentofacial Orthop. 2007;132:208-15
    [Google Scholar]
  2. . SmartClip versus conventional twin brackets for initial alignment: Is there a difference? Aust Orthod J. 2005;21:123-7
    [Google Scholar]
  3. . Self-ligating vs conventional twin brackets during en-masse space closure with sliding mechanics. Am J Orthod Dentofacial Orthop. 2007;132:223-5
    [Google Scholar]
  4. , , . A clinical trial of Damon 2 vs conventional twin brackets during initial alignment. Angle Orthod. 2006;76:480-5
    [Google Scholar]
  5. , , , . Efficiency of mandibular arch alignment with 2 preadjusted edgewise appliances. Am J Orthod Dentofacial Orthop. 2009;135:597-602
    [Google Scholar]
  6. , , , . Alignment efficiency of Damon3 self-ligating and conventional orthodontic bracket systems: A randomized clinical trial. Am J Orthod Dentofacial Orthop. 2008;134:470.e1-8
    [Google Scholar]
  7. , , . Effect of constant currents on orthodontic tooth movement in the cat. J Dent Res. 1975;54:251-4
    [Google Scholar]
  8. , , , , , . Electric currents, bone remodeling, and orthodontic tooth movement. I. The effect of electric currents on periodontal cyclic nucleotides. Am J Orthod. 1980;77:14-32
    [Google Scholar]
  9. , , , , , . Electric currents, bone remodeling, and orthodontic tooth movement. II. Increase in rate of tooth movement and periodontal cyclic nucleotide levels by combined force and electric current. Am J Orthod. 1980;77:33-47
    [Google Scholar]
  10. , , , , , , et al. Low-energy laser irradiation accelerates the velocity of tooth movement via stimulation of the alveolar bone remodeling. Orthod Craniofac Res. 2009;12:289-98
    [Google Scholar]
  11. , , , , , . The effect of low-level laser therapy during orthodontic movement: A preliminary study. Lasers Med Sci. 2008;23:27-33
    [Google Scholar]
  12. , , . Effects of two low-intensity laser therapy protocols on experimental tooth movement. Photomed Laser Surg. 2010;28:757-62
    [Google Scholar]
  13. , , , , , , et al. Laser-induced alveolar bone changes during orthodontic movement: A histological study on rodents. Photomed Laser Surg. 2010;28:823-30
    [Google Scholar]
  14. , , , . Metrical and histological investigation of the effects of low-level laser therapy on orthodontic tooth movement. Lasers Med Sci. 2012;27:131-40
    [Google Scholar]
  15. , , , , , , et al. Low-energy laser irradiation facilitates the velocity of tooth movement and the expressions of matrix metalloproteinase-9, cathepsin K, and alpha(v) beta(3) integrin in rats. Eur J Orthod. 2010;32:131-9
    [Google Scholar]
  16. , . Use of laser technology in orthodontics: Hard and soft tissue laser treatments. Eur J Paediatr Dent. 2010;11:44-8
    [Google Scholar]
  17. , , , , , . Low-level laser irradiation facilitates fibronectin and collagen type I turnover during tooth movement in rats. Lasers Med Sci. 2010;25:25-31
    [Google Scholar]
  18. , , , , , . Effect of low-frequency mechanical vibration on orthodontic tooth movement. Am J Orthod Dentofacial Orthop. 2015;148:440-9
    [Google Scholar]
  19. , , , , . Vibratory stimulation increases interleukin-1 beta secretion during orthodontic tooth movement. Angle Orthod 2015. [Epub ahead of print]
  20. , , , , , , et al. Supplemental vibrational force during orthodontic alignment: A randomized trial. J Dent Res. 2015;94:682-9
    [Google Scholar]
  21. , , , , , , et al. Periodontal tissue activation by vibration: Intermittent stimulation by resonance vibration accelerates experimental tooth movement in rats. Am J Orthod Dentofacial Orthop. 2008;133:572-83
    [Google Scholar]
  22. , , , . Effects of pulsed electromagnetic field vibration on tooth movement induced by magnetic and mechanical forces: A preliminary study. Aust Dent J. 2007;52:282-7
    [Google Scholar]
  23. , , , , , , et al. Photobiomodulation accelerates orthodontic alignment in the early phase of treatment. Prog Orthod. 2013;14:30
    [Google Scholar]
  24. , , , . Effect of LED-mediated-photobiomodulation therapy on orthodontic tooth movement and root resorption in rats. Lasers Med Sci. 2015;30:779-85
    [Google Scholar]
  25. , , . Prostaglandin as a mediator of bone resorption induced by experimental tooth movement in rats. J Dent Res. 1980;59:1635-42
    [Google Scholar]
  26. , , . The effect of prostaglandins on experimental tooth movement in monkeys (Macaca fuscata) J Dent Res. 1982;61:1444-6
    [Google Scholar]
  27. , , , , , . Clinical application of prostaglandin E1 (PGE1) upon orthodontic tooth movement. Am J Orthod. 1984;85:508-18
    [Google Scholar]
  28. , , , . Does human relaxin-2 affect peripheral blood mononuclear cells to increase inflammatory mediators in pathologic bone loss. ? Ann N Y Acad Sci. 2005;1041:317-9
    [Google Scholar]
  29. , , , . Use of relaxin in orthodontics. Ann N Y Acad Sci. 2005;1041:379-87
    [Google Scholar]
  30. , , , , . Does human relaxin accelerate orthodontic tooth movement in rats. ? Ann N Y Acad Sci. 2005;1041:388-94
    [Google Scholar]
  31. , , , . Effects of human relaxin on orthodontic tooth movement and periodontal ligaments in rats. Am J Orthod Dentofacial Orthop. 2007;131:8.e1-10
    [Google Scholar]
  32. , , , , . A randomized, placebo-controlled clinical trial on the effects of recombinant human relaxin on tooth movement and short-term stability. Am J Orthod Dentofacial Orthop. 2012;141:196-203
    [Google Scholar]
  33. , , , . Effectiveness of non-conventional methods for accelerated orthodontic tooth movement: A systematic review and meta-analysis. J Dent. 2014;42:1300-19
    [Google Scholar]
  34. . Accelerating orthodontic tooth movement using surgical and non-surgical approaches. Evid Based Dent. 2014;15:114-5
    [Google Scholar]
  35. , , . Efficacy of surgical and non-surgical interventions on accelerating orthodontic tooth movement: A systematic review. Eur J Oral Implantol. 2015;8:9-24
    [Google Scholar]
  36. , . Rapid canine retraction through distraction of the periodontal ligament. Am J Orthod Dentofacial Orthop. 1998;114:372-82
    [Google Scholar]
  37. . Distraction of the periodontal ligament: Rapid canine retraction. In: Samchukov M, Cope J, editors. Craniofacial Distraction Osteogenesis. Ch. 53. St. Louis: Mosby.
  38. . Dental distraction for an adult patient. Am J Orthod Dentofacial Orthop. 2003;123:683-9
    [Google Scholar]
  39. . Nonsurgical treatment with rapid mandibular canine retraction via periodontal ligament distraction in an adult with a Class III malocclusion. Am J Orthod Dentofacial Orthop. 2005;128:388-96
    [Google Scholar]
  40. , , , . Rapid canine distalization using distraction of the periodontal ligament: A preliminary clinical validation of the original technique. Angle Orthod. 2004;74:304-15
    [Google Scholar]
  41. , , , . Dentoalveolar distraction osteogenesis for rapid orthodontic canine retraction. J Oral Maxillofac Surg. 2002;60:389-94
    [Google Scholar]
  42. , , , . Rapid canine retraction and orthodontic treatment with dentoalveolar distraction osteogenesis. Am J Orthod Dentofacial Orthop. 2005;127:533-41
    [Google Scholar]
  43. , , , . Rapid canine distalization through segmental alveolar distraction osteogenesis. Angle Orthod. 2007;77:226-36
    [Google Scholar]
  44. , , , . Rapid orthodontics with alveolar reshaping: Two case reports of decrowding. Int J Periodontics Restorative Dent. 2001;21:9-19
    [Google Scholar]
  45. , , , . Rapid orthodontic decrowding with alveolar augmentation: Case report. World J Orthod. 2003;4:197-205
    [Google Scholar]
  46. , , . Effects of Corticision on paradental remodeling in orthodontic tooth movement. Angle Orthod. 2009;79:284-91
    [Google Scholar]
  47. , , , , , . Surgery-first accelerated orthognathic surgery: Postoperative rapid orthodontic tooth movement. J Oral Maxillofac Surg. 2011;69:781-5
    [Google Scholar]
  48. , , . Piezocision: A minimally invasive, periodontally accelerated orthodontic tooth movement procedure. Compend Contin Educ Dent. 2009;30:342-4
    [Google Scholar]
    :346-4
    [Google Scholar]
    :348-4
    [Google Scholar]
  49. , , . Accelerated orthodontic treatment with piezocision: A mini-invasive alternative to conventional corticotomies. Orthod Fr. 2011;82:311-9
    [Google Scholar]
  50. , , , , , . Effect of piezopuncture on tooth movement and bone remodeling in dogs. Am J Orthod Dentofacial Orthop. 2013;144:23-31
    [Google Scholar]
  51. , , , , , , et al. Effect of micro-osteoperforations on the rate of tooth movement. Am J Orthod Dentofacial Orthop. 2013;144:639-48
    [Google Scholar]
  52. , , , , . How does the amount of surgical insult affect bone around moving teeth. ? Am J Orthod Dentofacial Orthop. 2014;145:S92-9
    [Google Scholar]
  53. . The use of platelet-rich plasma to enhance the success of bone grafts around dental implants. Dent Implantol Update. 2000;11:17-21
    [Google Scholar]
  54. , , , , , . Bone conditioning to enhance implant osseointegration: An experimental study in pigs. Int J Oral Maxillofac Implants. 2003;18:505-11
    [Google Scholar]
  55. , , , , . Use of particulate dentin-plaster of Paris combination with/without platelet-rich plasma in the treatment of bone defects around implants. Int J Oral Maxillofac Implants. 2002;17:86-94
    [Google Scholar]
  56. , , , . A comparative study of osseointegration of Avana implants in a demineralized freeze-dried bone alone or with platelet-rich plasma. J Oral Maxillofac Surg. 2002;60:1018-25
    [Google Scholar]
  57. , , , , . Maxillary sinus augmentation with deproteinated bovine bone and platelet rich plasma with simultaneous insertion of endosseous implants. J Oral Maxillofac Surg. 2003;61:157-63
    [Google Scholar]
  58. , , , , , , et al. Influence of platelet-rich plasma on osseous healing of dental implants: A histologic and histomorphometric study in minipigs. Int J Oral Maxillofac Implants. 2003;18:15-22
    [Google Scholar]
  59. , , , , , , et al. Platelet-rich plasma contains high levels of platelet-derived growth factor and transforming growth factor-beta and modulates the proliferation of periodontally related cells in vitro. J Periodontol. 2003;74:849-57
    [Google Scholar]
  60. , , . Is platelet-rich plasma the perfect enhancement factor? A current review. Int J Oral Maxillofac Implants. 2003;18:93-103
    [Google Scholar]
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