• The Journal of Korean Academy of Prosthodontics
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• v.39 no.6
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• pp.659-681
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• 2001

Platelet-rich plasma(PRP) has been known to increase the rate and degree of bone formation by virtue of growth factors in concentrated platelets. Although its great healing effect on bone defect or pre-implantation site preparation in conjunction with bone substitute has been reported, the effect associated with implant is unknown. The purpose of this study was to investigate the effect of PRP on rapid osseointegration of endosseous dental implants in the rabbit tibiae. Twenty two adult female New Zealand white rabbits, weighing approximately 2.7-3.3kg, were used for this study. Twelve of the 22 animals were used for histomorphometric analysis and ten of the 22 were for removal torque test. Each animal received two implants in each tibia (two treated with PRP and two as control) and was given fluorochrome intramuscularly. For histomorphometric analysis, rabbits were divided into four groups according to the healing period. At 1 week, 2 weeks, 4 weeks and 8 weeks postoperatively, each three animals were sacrificed serially and the amount and rate of bone formation around dental implant were examined on the undecalcified sections under fluorescent microscope, polarized microscope and light microscope connected to a personal computer equipped with image analysis system. For removal torque test, rabbits were divided into two groups and removal torque tests were performed at 4 weeks, 10 weeks after implant placement. In total, 88 screw shaped, commercially pure titanium implants (Neoplant, Neobiotech, Seoul, Korea) were used in this study. Labeling pattern reflected differences of two groups in bone formation rate at each period. Histomorphometrically, PRP group showed significantly higher bone volume within threads compared to control group at 2 weeks ($70.30{\pm}4.96%$ vs. $50.68{\pm}6.33%$; P < .01) and 4 weeks ($82.59{\pm}5.94%$ vs. $72.94{\pm}4.57%$; P < .05 ). PRP group at 1, 2 and 4 weeks revealed similar degree of bone volume formation comparable to control group at 2, 4 and 8 weeks, respectively. On the other hand, while PRP group showed higher bone-implant contact ($47.37{\pm}8.09%$) than control group ($33.16{\pm}13.47%$) at 2 weeks, there were no significant differences between PRP group and control group for any experimental period. Removal torque values also showed no significant differences between PRP group and control group at any experimental period (P > .05). These findings imply that PRP could induce rapid, more bone formation around implant during early healing period and get faster secondary stability for reducing healing period, though it has not induced bone maturation enough to resist functional loading.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.4 no.2
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• pp.111-122
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• 2011

Platelet rich plasma (PRP) has been widely used nowadays for several common orthopaedic-related sports medicine conditions with the theoretical basis that PRP supplies numerous autologous growth factors from concentrated platelets needed to promote the healing process of injured tissue. Even though there are many basic sciences, animal studies and some clinical studies regarding PRP injections for musculoskeletal injuries which suggested good results, it is difficult to compare these various studies due to marked methodological differences such as PRP preparation method, the timing, volume and number of injection, and the outcome measurement tool. In addition, many studies have no control groups or a limited sample size, and there are few prospective randomized controlled trials assessing the efficacy of PRP injections. Therefore, well designed high-quality randomized studies are required to confirm the preliminary results until now and provide scientific evidence to support its use, and the paucity of scientific clinical evidence suggest that the administration of PRP on humans for musculoskeletal injuries should be performed with caution.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.6
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• pp.474-484
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• 2007

Purpose: The effect of platelet-rich plasma(PRP) on osteogenesis of marrow-derived osteoblasts on histomorphometric analysis in the mandible of rabbit was assessed. Materials and Method: Bone marrow cells were obtained from iliac bone of rabbits and were cultured in a Dulbecco's Modified Eagle's Medium(DMEM) with Dexamethasone, L-Ascortic acid, ${\beta}$-Glycerophosphate to proliferate and differentiate into osteoblasts for $4{\sim}5$ weeks. The expression of osteogenic mar-kers was detected by reverse transcription-polymerase chain reaction(RT-PCR) and silver nitrate stain. Then we prepared bony defects in the mandible of rabbit, 10.0mm in diameter and 4.0mm deep, by trephine bur. In the control group, the defects were filled with autogenous bone and cultured osteoblasts. In the experimental group, the defects were filled with autogenous bone, cultured osteoblasts and PRP. 2 weeks, 4 weeks, 8 weeks later, each group was evaluated with histological and histomorphometric analyses. Results: In vitro, osteoblasts were identified on RT-PCR and silver nitrate stain. According to histological observation, at 2 weeks well-developed anasto-mosing newly-formed woven bone was observed, at 4 weeks anastomosing newly-formed woven bone having osteoblastic activation was observed, and at 8 weeks thick newly-formed woven bone was observed in both control and experimental groups. According to histomorphometric analysis, there were 1.5% more newly-formed bone volume in experimental group than control group at 2 weeks, 28.4% more at 4 weeks, 4.3% more at 8 weeks. Particularly there were significant differences in bone volume at 4 weeks and 8 weeks new bone. Conclusion: Our results demonstrated PRP may enhance osteogenesis of marrow-derived osteoblasts at 4 weeks, 8 weeks.

• Journal of Veterinary Clinics
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• v.40 no.2
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• pp.93-103
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• 2023

The tendon is a dense connective tissue that connects muscle to bone and plays an essential role in joint motion. The injured tendon heals slowly owing to its low cellularity and vascularity. This study aimed to evaluate and compare the effects of regenerative injection therapy (RIT), 20 % dextrose prolotherapy (DP), and platelet-rich plasma (PRP) injections that can promote tendon healing. Twenty-one New Zealand white rabbits were divided into the control, DP, and PRP treatment groups. The superficial digital flexor tendon (SDFT) of the right hindlimb of each rabbit was used. A round defect of 2 mm was induced. Approximately 0.2 mL of 20% dextrose and autologous PRP were injected into the proximal and distal ends of the SDFT mass. Radiographic and ultrasonographic examination and cross-sectional area (CSA) calculations were performed pre-operatively and at 2, 4, and 8 weeks. The SDFT of both limbs was transected for biomechanical and histomorphometric evaluations. The SDFT of the left limb was transected for intact control. Semi-quantitative analysis was performed to evaluate the histomorphometric properties. Additional analysis was performed using H&E, Masson's trichrome, and immunohistochemical staining. The biomechanical evaluation showed that the treatment groups had higher tensile strength compared to the defect control group, while the PRP group had higher tensile strength than the DP group. On histological examination, the treatment groups appeared to be relatively closer to the remodeling phase of the healing process than the defect control group; the characteristics of the PRP group were closer to the remodeling phase than those of the DP group. The ultrasonographic examination showed different tendencies. Increased values in the CSA were observed during the early period in the treatment groups. This study suggests that PRP and DP can promote the healing of tendon injury, and these effects were superior with PRP than that with DP.

• Journal of Periodontal and Implant Science
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• v.53 no.1
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• pp.2-19
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• 2023

Purpose: Surgical techniques in orthodontics have received widespread attention in recent years. Meanwhile, biomaterials with high molecular content have been introduced, such as platelet concentrates (PCs), which may accelerate orthodontic tooth movement (OTM) and reduce periodontal damage. The present systematic review aimed to answer the following PICO question: "In patients in whom orthodontic surgical techniques are performed (P), what is the effectiveness of using PCs over the surgical site (I) when compared to not placing PCs (C) to achieve faster tooth movement (O)?" Methods: A search was performed in 6 databases. The criteria employed were those described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses declaration. The present review included studies with a control group that provided information about the influence of PCs on the rate of OTM. Results: The electronic search identified 10 studies that met the established criteria. Conclusions: The included studies were very diverse, making it difficult to draw convincing conclusions. However, a tendency was observed for OTM to be accelerated when PCs were used as an adjuvant for canine distalization after premolar extraction when distalization was started in the same session. Likewise, studies seem to indicate an association between PC injection and the amount of canine retraction. However, it is not possible to affirm that the use of PCs in corticotomy shortens the overall treatment time, as this question has not been studied adequately.

• Proceedings of the KSLP Conference
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• 2012.03a
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• pp.23-23
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• 2012

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.216-216
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• 2009

• Journal of Veterinary Clinics
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• v.40 no.3
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• pp.242-242
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• 2023

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.69-69
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• 1997

In the screening of tropical medicinal plants using PAE receptor binding assay, the ether extract of Ardisia crispa showed the potent antagonistic activity. Ardisia crispa have been used to heal the scurf, earache, orchitis, fever and diarrhoea, cough and given to the mother after childbirth to ‘wash out dirty blood’ in Malaysia. By means of activity guided isolation, compound AC7-1 was isolated as the potent PAF antagonist. In this study, antiplatelet effects of compound AC7-1 were examined in vitro platelet aggregation assay using the chronolog aggregometer. Compound AC7-1 inhibited PAF-, collagen-, ADP-, thrombin-induced platelet aggregation in human, rabbit and rat platelet rich plasma. In vitro rabbit platelet aggregation, the IC$\_$50/ value of compound AC7-1 was 5 ${\times}$ 10$\^$-6/ M against PAF(5 ${\times}$ 10$\^$-7/M)-induced aggregation. The IC$\_$50/ values of AC7-1 on PAF-induced platelet aggregation increased with increase of the concentration of PAF used. This result suggested the competitive nature of the AC7-1 antagonism. In vitro rat platelet aggregation, the IC$\_$50/ values of AC7-1 on collagen-, ADP-induced platelet aggregation were 4 ${\times}$ 10$\^$-6/ M, 2 ${\times}$ 10$\^$-5/ M, respectively. Also in vitro human platelet aggregation, AC7-1 potently inhibited both the primary phase and secondary phase of thrombin-induced aggregation.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.879-884
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• 2002

Previous study showed that an amidrazonophenylalanine derivative, LB30057, which has high water solubility, inhibited the catalytic activity of thrombin potently by interaction with the active site of thrombin. In the current investigation, we examined whether LB30057 inhibited platelet aggregation and vascular relaxation induced by thrombin. Treatment with LB30057 to plateletrich plasma (PRP) isolated from human blood resulted in a concentration-dependent inhibition of thrombin-induced aggregation. Values for $IC_{50}$ and $IC_{100}$ were $54{\pm}4$ nM and $96{\pm}3$ nM, respectively. This inhibition was agonist (thrombin) specific, since $IC_{50}$ values for collagen and ADP were \much greater than those for thrombin. In addition, concentration-dependent inhibitory effects were observed on the serotonin secretion induced by thrombin in PRP. Consistent with these findings, thrombin-induced increase in cytosolic calcium levels was inhibited in a concentration-dependent manner. When LB30057 was treated with aortic rings isolated from rats, LB30057 resulted in a concentration-dependent inhibition of thrombin-induced vascular relaxation. All these results suggest that LB30057 is a potent inhibitor of platelet aggregation and blood vessel relaxation induced by thrombin.