Indian Journal of Dental Research

: 2011  |  Volume : 22  |  Issue : 3  |  Page : 497--498

A comparative evaluation of healing with a computed tomography scan of bilateral periapical lesions treated with and without the use of platelet-rich plasma

Bruhvi Parikh1, S Navin2, P Vaishali1,  
1 Department of Conservative Dentistry and Endodontics, K. M. Shah Dental College and Hospital, Sumandeep Vidyapeeth University, Baroda, India
2 Department of Oral and Maxillofacial Surgery, K. M. Shah Dental College and Hospital, Sumandeep Vidyapeeth University, Baroda, India

Correspondence Address:
Bruhvi Parikh
Department of Conservative Dentistry and Endodontics, K. M. Shah Dental College and Hospital, Sumandeep Vidyapeeth University, Baroda


Periradicular surgery aims to achieve complete wound healing and regeneration of the periodontal unit. Platelet-rich plasma (PRP) is a platelet concentrate that is widely used to promote tissue healing, and bone induction through its various growth factors has been used in this study. This case report describes the use of PRP unilaterally in a bilateral periapical lesion in the same patient. The site treated with PRP showed better healing than the untreated site. This was confirmed with computed tomography (CT) scan readings. It was hypothesized that PRP could promote tissue regeneration and alveolar bone repair.

How to cite this article:
Parikh B, Navin S, Vaishali P. A comparative evaluation of healing with a computed tomography scan of bilateral periapical lesions treated with and without the use of platelet-rich plasma.Indian J Dent Res 2011;22:497-498

How to cite this URL:
Parikh B, Navin S, Vaishali P. A comparative evaluation of healing with a computed tomography scan of bilateral periapical lesions treated with and without the use of platelet-rich plasma. Indian J Dent Res [serial online] 2011 [cited 2020 Jan 23 ];22:497-498
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Full Text

The goal of dental treatment is to protect and maintain the patient's natural dentition over his/her lifetime for optimal comfort, function and esthetic appearance. After periodontal therapy or oral surgical procedures, healing proceeds by repair and regeneration. Repair is healing of a wound by tissues that do not fully restore the architecture or function of an affected unit. Regeneration, on the other hand, is reproduction or reconstitution of lost or injured part. Regenerative surgery, including the use of barrier membranes and graft materials, can reduce probing depths, support formation of periodontal ligament and allow regenerative rehabilitation and functional reconstruction.

Also, successful treatment of periapical inflammatory lesions depends on the reduction and elimination of the causative microorganisms. In cases where this cannot be achieved by conventional root canal therapy, periapical surgery might be an alternative. Periapical surgery includes the curettage of all periapical soft tissues and sometimes application of different biomaterials to enhance new bone formation at a defective site. The early stages of bone regeneration are characterized by the formation of a blood clot where platelet released signaling molecules accumulate, thereby providing a microenvironment that stimulates the immigration and proliferation of osteogenic progenitor cells. [1]

Platelet-rich plasma (PRP), an autologous modification of fibrin glue, is a simple strategy to concentrate platelets or to enrich the natural blood clot, which forms in normal surgical wounds, to initiate a more rapid and complete healing process apart from homeostasis. PRP was first introduced by Whitman et al. in 1997. The first clinical dental results with PRP were reported by Marx et al. in 1998, who strongly suggested that adding PRP to bone grafts accelerated the rate of bone formation and the degree of bone maturation was enhanced by a factor of 1.62-2.16. [2] It is now used in various applications with apparent clinical success without any risk of disease transmission.

The present paper narrates a case of bilateral periapical defects that were treated with and without the use of PRP in the same patient and followed over a period of 2 years. Postoperative healing was compared by radiograph and spiral computed tomography.

 Case Report

A 24-year-old male patient reported to the Department of Conservative Dentistry and Endodontics with the chief complaint of pain in relation to the upper central incisors that had fractured (Ellis class III) 10 years back. The fractured incisors had been treated with full coverage restorations, then by a general dentist, without any evidence of root canal therapy. On further examination, an intraoral sinus was observed in relation to the upper left central incisor. Pain on percussion was positive in relation to both his upper central incisors. The upper central incisors were discolored and crown preparation was evident. Vitality test showed negative response. On radiographic examination, bilateral periapical radiolucency was noticed. Thus, conventional root canal therapy was initiated [Figure 1]a. The canals were negotiated with K files ISO no. 15 (Mani,Togichi, Japan). Working length was determined using an electronic apex locator, Root ZX (J Morita, Koyoto, Japan). Using the crown down approach, chemomechanical preparation of the canals were completed with ISO no. 60 K files (Mani,Tochigi, Japan) in both the teeth. The canals were irrigated with 3% sodium hypochlorite intermittently and 17% ethylenediaminetetraacetic acid (EDTA) (Glyde, De Trey Dentsply , Konstanz, Germany) was used as a lubricant. The canals were dried with sterile paper points (Dentsply Maillefer, Addlestone, UK). Calcium hydroxide (Ultracal, Ultradent, Utah, USA) was placed as an intracanal medication for 3 weeks for two consecutive times. The pain persisted in both the incisors and the sinus tract did not heal in relation to upper left central incisor. Hence, a decision was taken to surgically treat the lesion. Obturation was completed using gutta-percha (Maillefer, Dentsply) and AH-plus sealer (De Trey Dentsply, Konstanz, Germany) with the lateral condensation method just prior to surgery. The access cavity was sealed with Cavit (3M ESPE, Seefeld, Germany). {Figure 1}

Periapical surgery was then performed by raising a full-thickness mucoperiosteal flap. The loss of labial cortical plate was evident in relation to the left central incisor periapically where the sinus tract was present. The cystic lining was enucleated bilaterally and sent for biopsy. (The biopsy confirmed the cystic lesion later.) Retrograde cavity preparations were done along the long axis of the tooth to a depth of 3-4 mm in both the central incisors. Mineral Trioxide Aggregate -MTA (ProRoot, Tulsa Dental, Johnson city,TN, USA) was used as a root-end filling material and was condensed with MTA pluggers (Rubinstein, Jedmed, St. louis, MO, USA) in the apical 3-4 mm.

PRP was prepared using the procedure described by Okuda et al. [3] Forty-five minutes before surgery, 8.5 ml of whole blood was drawn by venipuncture of the anticubital vein. Blood was collected in a 10-ml sterile glass tube coated with an anticoagulant (acid-citrate-dextrose). The amount of PRP derived was 2 ml. We used the Tisseel system for the preparation of PRP (Baxter Heath Corp., Deerfield, IL, USA). This system can be used for chair side preparation of PRP and even a small quantity of PRP (2 ml) can be prepared.

PRP was stored at 24°C until use for not more than 45 min. PRP gel was prepared by combining an equal volume of sterile saline solution containing 10% calcium chloride (calcium chloride nullifies the effect of the citrate anticoagulant used) and 100 U/ml of sterile bovine thrombin (an activator that allows polymerization of the fibrin into an insoluble gel, which causes the platelet to degranulate and release the indicated mediators and cytokines) to 2 ml of PRP. Since the defects were not continuous with each other, the PRP gel was carried with a periosteal elevator and placed at the site of larger defect (left side) unilaterally [Figure 2]. Wound closure was achieved with 4-0 Mersilk sutures (Ethicon, J and J, Livingston, Scotland). Analgesics and antibiotics were prescribed and the patient was instructed to gargle gently with chlorhexidine mouthwash for a week. The sutures were removed on the fourth day after surgery.{Figure 2}

The patient was recalled after 8 weeks, 1 year and 2 years postoperatively. Evaluation was done with radiographs and computed tomography (CT) scan. There was definite healing seen in the lesion treated with PRP on the radiograph [Figure 1]c. Thus, the amount of bone formation was more in relation to the periapical region of the left central incisor.


The exact mechanism by which periapical lesions are formed is not clearly understood. An inflammatory reaction may be evoked due to the persistence of intraradicular infections even after meticulous chemomechanical preparation and intraradicular medicaments or when the periapical region is colonized by microorganisms (extraradicular) which do not respond well to nonsurgical endodontic treatment. [4] Since in this case such chronic lesions were present (later confirmed with biopsy), surgical treatment was planned. During the process of PRP preparation, it is seen that each cubic millimeter of PRP solution contains a concentration of 1.5-2 million platelets (super concentrated). The main component of PRP solution is the high concentration [2] of growth factors present in alpha granules of platelets, which are required for wound healing.

Amongst the thirty growth factors that PRP contains, platelet-derived growth factor (PDGF), transforming growth factor-β (TGFβ-1 and β-2), and insulin-like growth factor (IGF), epidermal growth factor, vascular endothelial factor, and fibroblast growth factors are believed to play a major role in bone metabolism and potential regulation of cell proliferation. PDGF is known to be characteristic for monocytes and macrophages, and during wound healing, it is an activator of collagenase which promotes the strength of healed tissue. TGF-β activates fibroblasts to form procollagen, which results in the deposition of collagen within the wound. An osteoblast-specific transcription factor (cbfa1) which is essential for osteoblast differentiation is expressed by PRP. Furthermore, osteoprotegrin, inhibitor of osteoclastogenesis, is also present in PRP. It also acts as an anti-inflammatory agent by the production of RANTES/CCL5 (Regulated upon Activation, Normal T-cell Expressed and Secreted chemokine). CCL 5(chemokine ligand 5) is chemotactic for T cells, eosinophils and basophils, and plays an active role in recruiting leukocytes into inflammatory sites, blocking monocyte chemotactic protein-1 release from monocytes and its concentration of lipoxinA4, suggesting that PRP facilitates healing by controlling the local inflammatory response. [2] However, platelet effects are restricted to early stages of bone regeneration until the blood clot is replaced by granulation tissue, which is rich in osteogenic progenitor cells and blood vessels.

It has been found that PRP helps in healing even as early as 8 weeks. [2] Marx et al. reported successful healing of the mandibular segments using PRP. They assessed the bone density on X-ray films in a qualitative analysis. In this case, we have checked the amount of periapical bone regeneration with CT scan. It was found that the site treated with PRP showed better healing as early as 8 weeks compared to the other site. The CT scan measures the bone density in Hounsfield Unit (HU) at various sections. The CT scan after 1 year [Figure 3] shows increased bone density periapically in relation to the site treated with PRP (left central incisor). In the present case, the normal bone density was averaged to 750 HU in the maxillary anterior region (a difference of 50 units is insignificant in HU). The bone at the periapex of upper left central incisor showed an average density of 559 HU and the right central incisor had an average density of 398 HU (average of densities was calculated from CT scan at various sections and regions). The scan was done with a multidetector CT scanner (GE Healthcare, Milwaukee, USA, 16 slices/second). The exposure parameters were: field of vision - 17.1 cm; tube voltage - 120 kV; tube current - 100 mA (approx.). Several quantitative assessments based on CT scans have been reported, such as orbital measurements in enophtholmos, intracranial volume in craniosynostosis, and volume of mandible after distraction. [5] In contrary to this, certain reports have suggested that PRP when used alone does not benefit bone regeneration. [6] {Figure 3}

MTA was used in this case as a root-end filling material, as MTA prevents leakage better than glass ionomer cement and composite. The setting and subsequent leakage of MTA are not affected by the presence of blood. A layer of MTA would enhance the integrity of the apical barrier, making it more resistant to penetration by microorganisms, in effect, establishing a biologic barrier. MTA also augments the formation of new cementum which is essential for periodontal healing. [7]

In this study, a comparison between PRP-aided healing and normal healing process has been made on the same individual, which has led to the standardization of various factors, as various parameters like healing potential and immune responses of different individuals have been eliminated, thus reducing the potential of error. The interaction of MTA with PRP also needs to be assessed. At this point, sufficient long-term evidence and further controlled in vivo and in vitro studies are essential to understand the effect of PRP on osseous regeneration and the interaction of PRP with MTA.


1Gruber R, Kandler B, Fischer MB, Watzek G. Osteogenic differentiation induced by bone morphogenetic proteins can be suppressed by platelet-released supernatant. Clin Oral Implants Res 2006;17:188-93.
2Marx RE, Carlson ER, Eishstaed RM, Schimmele SR, Strauss JE, Georgeff KR. Platelet - rich plasma; Growth factor enhancement for bone grafts. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;96:638-46.
3Okuda K, Tai H, Tanabe K, Suzuki H, Sato T, Kawase T, et al. Platelet rich plasma combine with porous hyroxyapatite graft for the treatment of infrabony periodontal defects in humans: a comparative controlled clinical study. J Periodontol 2005;76:890-8.
4Nair PN. New perspectives on radicular cysts: do they heal? Int Endod J 1998;31:155-60.
5Carlson NE, Roach RB Jr. Platelet -rich plasma:clinical applications in dentistry. J Am Dent Assoc 2002;133:1383-6.
6Choi BH, Im CJ, Huh JY, Lee SH, Suh JJ. Effect of platelet rich plasma on bone regeneration in autogenous bone graft. Int J Oral Maxillofac Surg 2004;33:56-9.
7Torabinejad M, Watson TF, Pitt Ford TR. Sealing ability of a mineral trioxide aggregate when used as a root end filling material. J Endod 1993;19:591-5.