Treatment of Periapical Inflammatory Lesion with the Combination of Platelet-Rich Plasma and Tricalcium Phosphate: A Case Report

Application of platelet-rich fibrin and freeze-dried bone allograft following apicoectomy: A comparative assessment of radiographic healing

Background

Apicoectomy conceptualizes surgically maintaining a tooth with an endodontic lesion that cannot be resolved by conventional endodontic (re-) treatment. To achieve this, continuous improvement in surgical techniques, materials and instruments is being done to enhance the outcome of periapical endodontic surgeries. The purpose of this study was to compare, radiographically, the healing kinetics of platelet-rich fibrin (PRF) and mineralized freeze-dried bone allograft (FDBA) in patients undergoing apicoectomy.

Materials and Methods

Nineteen patients (aged 18-40 years) were included in the study and randomly assigned to groups A or B, where they received PRF or FDBA, respectively. Following apicoectomy, PRF gel and FDBA graft were prepared and placed in the osseous defect followed by placement of PRF membrane for graft stabilization and flap closure. Radiographic follow-up was done at the 1^st, 3^rd, 6^th and 12^th months for evaluation of healing using Molven's criteria. Statistical analysis was done with Pearson's and McNemar's Chi-square tests.

Results

A highly significant difference (P = 0.002) in radiographic healing was observed at 6 months. Complete healing was observed in 50% of cases in Group A whereas in Group B, none of the cases presented with complete radiographic healing. However, at the end of 12 months, complete radiographic healing was observed in both groups.

Conclusion

Our data suggest that PRF accelerates bone healing as compared to FDBA and is both time and cost-efficient.

Protective Actions in Apical Periodontitis: The Regenerative Bioactivities Led by Mesenchymal Stem Cells

Resulting from bacterial infection, apical periodontitis (AP) is a common inflammatory disease of the periapical region of the tooth. The regeneration of the destroyed periapical alveolar bone and the surrounding periodontium tissues has long been a difficult task in clinical practice. These lesions are closely related to pathogen invasion and an overreactive immune response. It is worth noting that the protective healing process occurs simultaneously, in which mesenchymal stem cells (MSCs) have a crucial function in mediating the immune system and promoting regeneration. Here, we review the recent studies related to AP, with a focus on the regulatory network of MSCs. We also discuss the potential therapeutic approaches of MSCs in inflammatory diseases to provide a basis for promoting tissue regeneration and modulating inflammation in AP. A deeper understanding of the protective action of MSCs and the regulatory networks will help to delineate the underlying mechanisms of AP and pave the way for stem-cell-based regenerative medicine in the future.

Plasma Rich in Growth Factors in the Treatment of Endodontic Periapical Lesions in Adult Patients: A Narrative Review

Platelet concentrates have been widely used in regenerative medicine, including endodontics. The aim of this manuscript was to assess critically the efficacy of PRF in the treatment of endodontic periapical lesions in adult patients on the basis of the literature. The PICO approach was used to properly develop literature search strategies. The PubMed database was analyzed with the keywords: "((PRP) OR (PRF) OR (PRGF) OR (CGF)) AND (endodontic) AND ((treatment) OR (therapy))". After screening of 155 results, 14 articles were included in this review. Different types of platelet concentrates are able to stimulate the processes of proliferation and differentiation of mesenchymal stem cells. Platelet rich fibrin (PRF) releases growth factors for at least 7 days at the application site. Growth factors and released cytokines stimulate the activity of osteoblasts. Moreover, the release of growth factors accelerates tissue regeneration by increasing the migration of fibroblasts. It was not possible to assess the efficacy of PRF supplementation in the treatment of endodontic periapical lesions in permanent, mature teeth with closed apexes, due to the lack of well-designed scientific research. Further studies are needed to analyze the effect of PRF on the healing processes in the periapical region.

Plasma Rich in Growth Factors in the Treatment of Endodontic Periapical Lesions in Adult Patients: Case Reports

Platelet-rich fibrin (PRF) is an autologous blood concentrate obtained without anticoagulants by centrifugation of patients’ peripheral venous blood. PRF is considered to enhance the formation of new bone. The aim of this manuscript was to present two case reports of permanent teeth with closed apexes with periapical lesions, treated endodontically with the use of PRF. The root canals were mechanically cleaned and shaped with NiTi files and irrigated with 5.25% sodium hypochlorite (NaOCl), 40% citric acid (CA), and triple distillated water. Before the canal systems were obturated, A-PRF was used as a scaffold and was placed below the cementodentinal junction with hand pluggers. Cone beam computerized tomography (CBCT) was used to assess the resolutions of periapical radiolucencies. After 6 months, the measurements of both periapical lesions were significantly reduced. Although the performed root canal treatments (RCTs) can definitely be recognized as successful, it must be emphasized that mechanical shaping and cleaning of the root canals with special disinfecting solutions significantly affect the clinical efficacy of RCT. It seems impossible to state that PRF played a leading role in the healing process of the presented periapical lesions. Further studies must be performed to assess whether RCT of mature teeth with an additional PRF application is superior to RCT performed alone.

Treatment of apicomarginal defect with periapical surgery: A case report

An apicomarginal defect can be explained as a total loss of buccal alveolus extending from the original crestal bone to the apex of the tooth. This study presents a case of an apicomarginal defect in a first left molar subjected to periapical surgery with vestibular cortex block replacement and A-PRF + membrane coating approximately one year ago. One-year clinical follow-up was performed, with no evidence of recurrence. This case report discusses periapical surgical treatment and the importance of an interdisciplinary approach to the management of teeth with apicomarginal defects.

Key words:Periapical surgery, apicomarginal defect, A-PRF+, bone graft.

Use of bovine colostrum in periapical defects following surgical endodontics: Two case reports

Periapical lesions are the most common pathological conditions involving teeth which often require surgical intervention. To achieve optimal healing both clinically and radiographically, bone grafts and barrier membranes have been used to fill the periapical defect after degranulation of the lesion. Colostrum is one of the new materials, which has osteoinductive or regenerative potential. The present case reports describe the use of bovine colostrum in the treatment of periapical inflammatory lesion with a follow-up period of 12 months. These case reports suggest that colostrum can be used to fill the periapical defect after degranulation, which has a favorable outcome.

Combination of hydroxyapatite, platelet rich fibrin and amnion membrane as a novel therapeutic option in regenerative periapical endodontic surgery: Case series

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Our article was an attempt to focus on combined benefits of Bio-Gen mix^®, PRF and amnion membrane to provide a viable regenerative option in periapical surgery.

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To the best of our knowledge, there has been no evidence related to the application of a human placental membrane in periapical surgery. Our presented case reports provide an insight into this novel therapeutic option.

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The presented case reports confirm that the amnion membrane combined with bone graft and PRF have enhanced the healing outcomes and provided endodontists a sustainable tool while performing surgeries in the esthetic zone.

Introduction

Periapical surgery is the last resort in the arsenal of an endodontist to effectively deal with periapical lesions that result from necrosis of the pulp. Bone grafts, growth factors and membranes form an array of regenerative materials that influence the healing outcome of periapical surgery.

Presentation of case

The main purpose of the two cases reported here was to assess the potential benefits of a combination of bone graft, platelet-rich fibrin (PRF) and amnion membrane in terms of reduced post-operative discomfort, radiographic evidence of accelerated periapical bone healing and present a novel therapeutic option in the management of large periapical lesions. Two cases of radicular cysts were treated through a combined regenerative approachof Bio-Gen mix^®, PRF and amnion membrane. The patients were assessed for discomfort immediate post-operatively and after a week. The patients were recalled every month for the next 6 months for radiographic assessment of the periapical healing.

Discussion

Literature is replete with articles that have substantiated the role of demineralized bone matrix comprising a mixture of cancellous and cortical bone graft particles in enhancing regeneration. To the best of our knowledge, there has been no evidence related to the application of a human placental membrane in periapical surgery. Hence, the rationale of using a combined approach of Bio-Gen mix^®, PRF and amnion membrane was to combine the individual advantages of these materials to enhance clinical and radiographic healing outcomes. Our present case reports provide an insight into this novel therapeutic option.

Conclusion

The results of this case seriessubstantiatesthe credibility of using a combination ofamnion membrane with a bone graft and PRF to enhance radiographic healing outcome with decreased post-operative discomfort and present a viable regenerative treatment modality in periapical surgery.

The impact of autologous platelet concentrates on endodontic healing: a systematic review

The current literature was reviewed to determine the impact of autologous platelet concentrates (APCs) on endodontic healing. All types of clinical study designs concerning any kind of endodontic treatment involving the application of APCs were included. Two independent reviewers searched three databases (PubMed, Embase, and Cochrane Library) for studies, complemented by hand search, until 16/1/2016. From the 423 identified records, 48 articles met the inclusion criteria. Selected randomized controlled clinical trials (RCTs) underwent Cochrane Collaboration's risk-of-bias assessment and data extraction. Only two RCTs showed low risk of bias. There was considerable heterogeneity between the RCTs with regard to the type of therapy, type of APCs, assessment method, and study quality, and therefore the data could not be analyzed quantitatively. The included case reports/series and non-randomized comparative studies underwent qualitative analysis with the revised Methodological Index for Non-Randomized Studies (MINORS) and data extraction. The two comparative non-randomized studies scored qualitatively high, though the MINORS-scores of the case series and reports were dispersed. APCs were involved in five endodontic treatment modalities, namely apexification, regenerative endodontic procedures, pulpotomy, apical surgery, and treatment of endo-perio/perio-endo lesions. APCs seem to accelerate postoperative bone healing, augment the patients' postoperative quality of life, aid further root development, and support maintenance/regaining of pulp vitality. No adverse events were reported. APCs in endodontic treatments seem to contribute to the healing of soft and hard tissues, though there is a lack of long-term high quality clinical trials and standardized treatment protocols.

Management of a Previously Treated, Calcified, and Dilacerated Maxillary Lateral Incisor: A Combined Nonsurgical/Surgical Approach Assisted by Cone-beam Computed Tomography

Teeth with calcified canals, dilacerated roots, and associated large periradicular lesions involving both cortical plates pose a challenge to dentists. In addition to the nonsurgical endodontic treatment, such teeth may require surgical intervention with concomitant use of bone grafting materials and barrier techniques. These techniques, when combined with the use of a host modulating agent such as platelet-rich fibrin (PRF), may improve the chances of success. A 26-year-old woman was referred for dental treatment with a recurrence of an intraoral sinus tract 2 months after periradicular surgery in the upper anterior region. Clinical and radiographic examinations revealed a calcified and perforated maxillary left lateral incisor with a severely dilacerated root as well as an associated large radiolucent lesion surrounding the roots of the maxillary left central and lateral incisors. A cone-beam computed tomographic scan of the anterior maxilla showed erosion of the labial and palatal cortical plates in the same region. A calcified canal in the lateral incisor was negotiated up to the straight line portion of the canal. Periradicular surgery with root-end resection was performed, and root-end filling was performed with mineral trioxide aggregate. The perforation present on the middle third of the labial surface of the root was repaired with mineral trioxide aggregate, and the canal was cleaned, shaped, and obturated. A PRF scaffold was prepared and used with a collagen membrane and a freeze-dried bone allograft. Follow-up visits after 3 months, 6 months, and 1 year revealed satisfactory clinical and radiographic healing. The combined use of nonsurgical and surgical modes of treatment cannot be overemphasized in this case. The use of PRF along with a bone graft and a barrier membrane may have enhanced the speed of healing and the resolution of periradicular radiolucency by enhancing bone regeneration.

Management of large preiapical lesion with the combination of second generation platelet extract and hydroxyapatite bone graft: a report of three cases

The pulp tissue necrosis and extensive periodontal diseases leads to the development of the inflammatory periapical lesion which causes a local response of bone around the apex of the tooth. Depends upon the nature of wound and available biological growth factors the outcome will be either regeneration or repair. Being a rich source of growth factors, platelet rich fibrin (PRF) posses many advantages in bone regeneration. The purpose of this case report is to present an attempt to evaluate the healing potential of the combination of PRF and Hydroxyapatite bone graft as opposed to using these materials alone. A periapical endodontic surgery was performed on three patients with a large periapical inflammatory lesion and a large bony defect. The defect was then filled with a combination of PRF and Hydroxyapatite bone graft crystals. Clinical examination exhibited uneventful wound healing. The HA crystals have been replaced by new bone radiographically at the end of two years in Case 1 and Case 2, Case 3 were followed upto one year. On the basis of our cases outcome, we conclude the use of PRF in combination with HA crystals might have accelerate the bone regeneration.

Platelet-rich plasma in bone regeneration: engineering the delivery for improved clinical efficacy

Human bone is a tissue with a fairly remarkable inherent capacity for regeneration; however, this regenerative capacity has its limitations, and defects larger than a critical size lack the ability to spontaneously heal. As such, the development and clinical translation of effective bone regeneration modalities are paramount. One regenerative medicine approach that is beginning to gain momentum in the clinical setting is the use of platelet-rich plasma (PRP). PRP therapy is essentially a method for concentrating platelets and their intrinsic growth factors to stimulate and accelerate a healing response. While PRP has shown some efficacy in both in vitro and in vivo scenarios, to date its use and delivery have not been optimized for bone regeneration. Issues remain with the effective delivery of the platelet-derived growth factors to a localized site of injury, the activation and temporal release of the growth factors, and the rate of growth factor clearance. This review will briefly describe the physiological principles behind PRP use and then discuss how engineering its method of delivery may ultimately impact its ability to successfully translate to widespread clinical use.

Combination of platelet rich fibrin, hydroxyapatite and PRF membrane in the management of large inflammatory periapical lesion

Periapical inflammatory lesion is the local response of bone around the apex of tooth that develops after the necrosis of the pulp tissue or extensive periodontal disease. The final outcome of the nature of wound healing after endodontic surgery can be repair or regeneration depending on the nature of the wound; the availability of progenitor cells; signaling molecules; and micro-environmental cues such as adhesion molecules, extracellular matrix, and associated non-collagenous protein molecules. The purpose of this case report is to add knowledge to the existing literature about the combined use of graft material [platelet rich fibrin (PRF) and hydroxyapatite (HA)] and barrier membrane in the treatment of large periapical lesion. A periapical endodontic surgery was performed on a 45 year old male patient with a swelling in the upper front teeth region and a large bony defect radiologically. The surgical defect was filled with a combination of PRF and HA bone graft crystals. The defect was covered by PRF membrane and sutured. Clinical examination revealed uneventful wound healing. Radiologically the HA crystals have been completely replaced by new bone at the end of 2 years. On the basis of the results obtained in our case report, we hypothesize that the use of PRF in conjunction with HA crystals might have accelerated the resorption of the graft crystals and would have induced the rapid rate of bone formation.

Effect of Platelet-Rich Plasma on the Outcome of Early Loaded Dental Implants: A 3-Year Follow-up Study

This study evaluated the effect of local application of platelet-rich plasma (PRP) on the outcome of early loaded implants. Two implants were placed in the posterior region or bilaterally symmetric to the median line of the maxilla. Then, PRP was either applied or not applied to the implant sockets. Outcome measures were prosthesis and implant success as well as biological and prosthetic complications. Stability of individual implants was assessed manually and with a resonance frequency analysis device. The implant stability quotient (ISQ) was recorded on the operation day, on postoperative day 4, and at postoperative week 1. At the end of the first postoperative week, implants with ISQ values >60 were early loaded on day 7 with metal-ceramic crowns. Measurements were repeated at postoperative weeks 2, 3, and 4 and at postoperative months 6, 12, 24, and 36. One of the 64 implants was dropped out after 3 months of loading. No prosthesis failed. There were no prosthetic complications. Statistical analysis revealed significant differences between ISQ values of PRP and non-PRP implants on the operation day. Moreover, no statistically significant differences were found between ISQ values of PRP and non-PRP implants in the follow-up periods (P > .05). No appreciable clinical effect was observed when using PRP in the maxilla.

Autologous platelet rich plasma after third molar surgery: a comparative study

PURPOSE

This study is an attempt to evaluate the use of autologous platelet rich plasma (PRP) to promote wound healing and osseous regeneration in human third molar extraction sockets.

MATERIALS AND METHOD

PRP was prepared after two centrifugation and the gelling agent used was freshly prepared 10% calcium chloride.PRP gel was placed in one of the extracted sockets of bilateral impacted mandibular third molars. IOPA Xrays were used to evaluate the wound dehiscence, probing depth, bone density & alveolar bone level after 1st, 2nd and 7th day and 3rd & 6th month respectively.

RESULTS

On evaluation, it was found that PRP grafted sockets showed dehiscence in 8% cases. The decrease in alveolar bone level was highly significant in PRP grafted sockets in 3rd and 6th month post operatively. There was significant difference between pre-operative density of adjacent bone and bone formed in extraction sockets at 3rd and 6th month in PRP grafted sockets. There was significant reduction in probing depth from initial period to 3 and 6 months in both the groups, but PRP grafted sockets showed greater decrease in probing depth.

CONCLUSION

PRP is an inexpensive and widely available modality to minimize postoperative complication and enhance both hard and soft tissue healing potentials. This autologous product eliminates concern about immunogenic reaction and disease transmission. Its beneficial outcomes in dental clinic, including decrease in bleeding and rapid wound healing hold promise for further procedures.PRP is thus a new application in tissue engineering and developing area for clinician and researchers.

Regenerative therapy as an adjunct to periapical surgery: a case report

Large periapical defects may adversely affect the success rate of endodontic surgery. Use of regenerative therapy may enhance the prognosis of such teeth. A case of traumatized upper anterior teeth with infected radicular cyst and associated sinus tract reported to the dental hospital. A periradicular surgical procedure was performed to remove the nonhealing pathological tissue. To augment the repair a bioactive bone graft material was placed. Six months interim results showed positive outcome of application of graft.

How to cite this article: Chaturvedy V, Chaturvedy S. Regenerative Therapy as an Adjunct to Periapical Surgery: A Case Report. Int J Clin Pediatr Dent 2012;5(1):75-77.

Treatment of endodontically induced periapical lesions using hydroxyapatite, platelet-rich plasma, and a combination of both: An in vivo study

Aim and Objectives:

To evaluate bone regeneration in endodontically induced periapical lesions using Hydroxyapatite, Platelet-Rich Plasma (PRP), and a combination of Hydroxyapatite and Platelet-Rich Plasma for a period of one year.

Materials and Methods:

Twenty systemically healthy patients of both genders between the ages 20 and 40 years were included. To qualify, the patient had to have a tooth where non-surgical root canal therapy had failed, periapical radiolucency was present, and periapical root end surgery was required. The bony defect had to be confined to the apical area, with the bone covering the entire root surface coronally, with an intact lingual cortical plate. Patients were randomly divided into four groups, with five patients each, as follows: Group I — Replacement with Hydroxyapatite, Group II — Replacement with PRP, Group III — Replacement with PRP and Hydroxyapatite, and Group IV — Control group with no substitutes. The patients were evaluated both clinically and radiographically.

Results:

The radiographic evaluation revealed that Group I patients showed complete bone regeneration with evidence of a trabecular pattern, at the end of one year, Group II patients showed complete bone regeneration at the end of nine months, Group III patients showed complete bone regeneration at the end of six months, and Group IV patients showed bone regeneration, which was not satisfactory even after one year.

Conclusions:

The PRP and Hydroxyapatite combination facilitated better and faster bone regeneration when compared to PRP alone.

Revitalization of tooth with necrotic pulp and open apex by using platelet-rich plasma: a case report

INTRODUCTION

A growing body of evidence is demonstrating the possibility for regeneration of tissues within the pulp space and continued root development in teeth with necrotic pulps and open apexes. The purpose of this case report is to add a regenerative endodontic case to the existing literature about using platelet-rich plasma (PRP).

METHODS

An 11-year-old boy whose maxillary second premolar tooth had been accidently extracted and immediately replanted developed pulpal necrosis and symptomatic apical periodontitis. After preparing an access cavity, its necrotic pulp was removed. The canal was irrigated with 5.25% NaOCl solution and dried with paper points. A triple antibiotic mixed with distilled water was packed in the canal and left for 22 days. Twenty milliliters of whole blood was drawn from the patient's forearm for preparation of PRP. After removal of the antibiotic mixture, the PRP was injected into the canal space up to the cementoenamel junction level. Three millimeters of grey mineral trioxide aggregate was placed directly over the PRP clot. Three days later, the tooth was double-sealed with permanent filling materials.

RESULTS

Clinical examination 5 1/2 half months later revealed no sensitivity to percussion or palpation tests. Radiographic examination of this tooth showed resolution of the periapical lesion, further root development, and continued apical closure. Sensitivity tests with cold and an electric pulp test elicited a positive response similar to those found in the first premolar tooth.

CONCLUSIONS

On the basis of short-term results of the present case, it appears that regeneration of vital tissues in a tooth with necrotic pulp and a periapical lesion is possible; PRP is potentially an ideal scaffold for this procedure.

Periodontal wound healing with and without platelet-rich plasma: histologic observations and assessment of flap tensile strength

BACKGROUND

Platelet-rich plasma (PRP) has been promoted as a surgical adjunct to enhance hard and soft tissue wound healing. Although anecdotally reported to be of value, the results of controlled studies examining the added effects of PRP on surgical procedures have been mixed. The purpose of this study was to test the effect of PRP on flap strength at various post-surgical time points in a minipig animal model.

METHODS

Twelve Yucatan minipigs provided four sites per animal. PRP was prepared from each animal at the time of surgery. Following reflection of a mucoperiosteal flap in each quadrant, subgingival plaque and calculus were removed. Each surgical site was irrigated with sterile saline; prior to suturing, one randomly selected test quadrant in each arch was treated with PRP. Four animals were euthanized at day 14, and two animals were euthanized at 2, 7, 10, and 28 days. The flap strength in each quadrant was tested by attaching to a loop of 3-0 silk suture through the tissue; the force required to separate the flap from the tooth/bone interface was recorded for each site. A separate portion of each flap site was prepared for descriptive histologic examination, including inflammation, hemorrhage, and new bone growth.

RESULTS

Flap strength was significantly less on day 2 compared to later time points, and there were no significant differences between the test and control groups. No histologic differences in healing between test and control sites were seen at any time point.

CONCLUSIONS

PRP did not seem to contribute to greater flap strength at any post-surgical time point, nor was it associated with any histologic differences in wound healing in this Yucatan minipig model. The time points chosen for observation post-surgery, as well as the variability in the PRP platelet count, may have contributed to the lack of positive findings in this study.

Bioactive materials in endodontics

Endodontic treatment in dentistry is a delicate procedure and many treatment attempts fail. Despite constant development of new root canal filling techniques, the clinician is confronted with both a complex root canal system and the use of filling materials that are harmful for periapical tissues. This paper evaluates reported studies on biomaterials used in endodontics, including calcium hydroxide, mineral trioxide aggregate, calcium phosphate ceramics and calcium phosphate cements. Special emphasis is made on promising new biomaterials, such as injectable bone substitute and injectable calcium phosphate cements. These materials, which combine biocompatibility, bioactivity and rheological properties, could be good alternatives in endodontics as root canal fillers. They could also be used as drug-delivery vehicles (e.g., for antibiotics and growth factors) or as scaffolds in pulp tissue engineering.

Single-step apical barrier placement in immature teeth using mineral trioxide aggregate and management of periapical inflammatory lesion using platelet-rich plasma and hydroxyapatite

We present here a case report of a tooth with an immature root with a large periapical lesion. The open apex was managed by placing an apical barrier using mineral trioxide aggregate, and the periapical lesion was treated surgically. A combination of platelet-rich plasma (PRP) and hydroxyapatite graft (HA) was used to achieve faster healing of the periapical lesion. The case was followed up for 11 months. The indications and advantages of apical barrier placement, periapical surgery, and the role of PRP and HA in postsurgical healing are discussed.

Use of platelet gel with connective tissue grafts for root coverage: a randomized-controlled trial

BACKGROUND

Platelet-rich plasma (PRP) was speculated to be a promoter of periodontal regeneration. There are only a few clinical comparative studies using PRP in the treatment of gingival recession.

AIM

The aim of the present study was to compare connective tissue graft (CTG)+PRP with CTG alone in the treatment of gingival recession.

MATERIAL AND METHODS

Forty patients with Miller I/II recessions were included. Each recession was randomly treated with either CTG+PRP or CTG. Clinical variables were recorded at baseline and at 6 weeks, 6 and 12 months. Root coverage (RC) and attachment gain (AG) were also calculated.

RESULTS

Probing depth, recession depth, clinical attachment level, keratinized tissue width and recession width (RW) were improved in both study groups. However, no difference was observed between groups, except RW. RW in the control group was statistically lower than the test group at all follow-up periods.

CONCLUSION

Treatment of recession with CTG or a CTG-PRP combination resulted in favourable clinical outcomes. However, no difference could be found between CTG and CTG+PRP. Whether much longer follow-up studies with higher statistical power may change these results remains questionable.

Correlation Between Platelet-derived Growth Factor B Chain and Bone Resorption in Rat Periapical Lesions

The purpose of this study was to examine the relationship between platelet-derived growth factor B chain (PDGF-B) and bone resorption in rat periapical lesions. Periapical lesions were induced in Sprague-Dawley rats by occlusal exposure of the pulp of their mandibular first molars. Animals were sacrificed randomly at 0, 7, 14, 21, and 28 days after the exposure, and frontal sections were prepared for immunohistochemistry and enzymehistochemistry. PDGF-B-positive cells and osteoclasts could be observed on day 7. From day 7 to day 14, the number of PDGF-B-positive cells and osteoclasts were ascending, and a significant correlation was found between them; from day 21 to day 28, more PDGF-B-positive cells and fewer osteoclasts could be observed, and the positive expression of PDGF-B was negatively correlated with osteoclasts. These findings showed that PDGF-B could be observed, which might be associated with the bone resorption of periapical lesions.

Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part I: technological concepts and evolution

Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates geared to simplified preparation without biochemical blood handling. In this initial article, we describe the conceptual and technical evolution from fibrin glues to platelet concentrates. This retrospective analysis is necessary for the understanding of fibrin technologies and the evaluation of the biochemical properties of 3 generations of surgical additives, respectively fibrin adhesives, concentrated platelet-rich plasma (cPRP) and PRF. Indeed, the 3-dimensional fibrin architecture is deeply dependent on artificial clinical polymerization processes, such as massive bovine thrombin addition. Currently, the slow polymerization during PRF preparation seems to generate a fibrin network very similar to the natural one. Such a network leads to a more efficient cell migration and proliferation and thus cicatrization.