Platelet Rich Fibrin in the revitalization of tooth with necrotic pulp and open apex

Regenerative endodontic treatment and traumatic dental injuries

Pulp necrosis is the most common complication following dental trauma and is often associated with apical periodontitis. The management of these teeth is challenging in terms of large root canals, open apices, thin dentinal walls, and short roots. Over decades the conventional treatment for these teeth was calcium hydroxide apexification, a time-consuming procedure despite high success rates. Subsequently after the introduction of mineral trioxide aggregate and hydraulic calcium silicate materials single visit apical plug procedures became increasingly practiced with comparable success rates to the conventional apexification. The search continued afterward for a clinical procedure that may stimulate further root development and apical closure to avoid the long-term complication of root fracture after apexification. Regenerative procedures using stem cells derived from the apical papilla and blood clots as scaffolds were then introduced for the management of immature teeth, with variable protocols and success rates. This review will cover the evidence available and current position of regenerative endodontic procedures in traumatized immature teeth with apical periodontitis, in terms of clinical protocols, outcome, and potential prognostic factors.

Platelet-Rich Fibrin: A Self-Derived Biomaterial for Surgical Treatment of a Periapical Lesion

This case report explores the application of platelet-rich fibrin (PRF) as an autologous biomaterial in the surgical management of a periapical cyst in an 18-year-old female patient. The patient presented with pain, discoloration, and swelling in the maxillary left central incisor region, indicative of an asymptomatic periapical lesion associated with a history of trauma. Despite initial endodontic treatment with calcium hydroxide, the lesion persisted, necessitating surgical intervention. PRF, prepared from the patient's blood, was utilized during periapical surgery to promote healing and tissue regeneration. The surgical procedure included enucleation of the cyst, apicoectomy, and retrograde filling with Biodentine. Clinical and radiographic assessments at follow-up visits (three, six, and nine months post-surgery) revealed successful healing with no signs of inflammation or discomfort. The use of PRF demonstrated favorable outcomes in enhancing wound healing and maintaining a favorable environment for tissue remodeling. This case underscores the potential of PRF as an effective biomaterial in periapical surgery, advocating for its integration into dental therapeutic strategies for its regenerative properties and cost-effectiveness.

Revascularization of a Permanent Tooth with Necrotic Pulp and Apical Periodontitis

This case report details a pulp revascularization treatment administered to a mature permanent tooth exhibiting pulp necrosis. A 22-years old female patient complained of the recurrence of a sinus tract labial of the maxillary right central incisor; which was tender on biting. Diagnosis of pulp necrosis and symptomatic apical periodontitis. Preoperative periapical and CBCT radiographs showed root with wide apical foramen and large apical radiolucency. Pulp revascularization procedure was performed using 1.3% sodium hypochlorite irrigation, 17% Ethylenediaminetetraacetic acid irrigation, and calcium hydroxide intracanal dressing for 2 weeks. During the last visit, intentional bleeding was induced, collagen matrix was set over the blood clot, 2 mm of mineral trioxide aggregate and glass-ionomer filling was placed. A year of follow-up, the tooth showed no signs or symptoms and responded normally to the sensibility tests. Intra-oral periapical radiograph and the CBCT showed significant reduction in the periapical lesion's size, slight reduction in the apical foramen's size, and hard radiopaque material deposition at the root's middle third.

Two-Dimensional Radiographs and Cone-beam Computed Tomography Assessment of Concentrated Growth Factor and Platelet-Rich Fibrin Scaffolds in Regenerative Endodontic Treatment of Immature Incisors with Periapical Radiolucency: A Randomized Clinical Trial

INTRODUCTION

The primary aim of this study was to compare the radiographic changes of immature incisors with periapical radiolucency after treatment with platelet-rich fibrin (PRF) and concentrated growth factor (CGF) platelet concentrate scaffolds as well as assessment of the clinical success rate over 12 months. The secondary aim was to monitor the radiographic changes in terms of reduction of periapical lesion diameter (PALD), root dentine thickness (RDT), root length (RL), and apical foramen width (AFW). The tertiary aim was to assess and pulp responses, after 12 months.

METHODS

Fifty six children with seventy necrotic, single-rooted maxillary incisors with periapical radiolucency were treated with either CGF or PRF scaffolds (35 teeth per group). Two patients with 4 teeth (2 teeth in each group) failed to attain the follow-up recalls. Radiographic changes in terms of reduction of PALD, RDT, RL, and AFW were monitored using a 2-dimensional (2D) radiograph and cone-beam computed tomography (CBCT) scan. The clinical performance of teeth receiving both scaffolds was assessed after 6 and 12 months. Categorical and continuous data were analyzed using the chi-square test and the t test, respectively. The time and group effects on the means of different radiographic dimensions were tested using the general linear model. Bland-Altman plots were used to assess the level of agreement between the 2D radiographs and CBCT. The level of significance was defined at 0.05 and a 95% confidence interval.

RESULTS

The means of PALD and RL showed significant enhancement in the CGF group compared to the PRF group (P < .05). While the difference between the 2 scaffolds in terms of RDT and AFW was not significant (P > .05). The findings of the 2D radiograph and CBCT were consistent. Clinically, both scaffold success rates were similar (93.9%) over the follow-up intervals. The influence of study independent variables had no significant effect on the success of the regenerative endodontic procedures outcome (P > .05). There was no significant difference in the positive pulp responses to the thermal and electric pulp tests after one year of treatment (P > .05).

CONCLUSIONS

According to the short-term follow-up, PRF and CGF were successful in treating immature teeth with periapical radiolucency by regenerative endodontics. Both scaffold systems induced periapical healing and root lengthening with significant superiority of CGF.

Role of Platelet Concentrates in Dental-Pulp Regeneration: A Systematic Review of Randomized Clinical Trials

Statement of the Problem

Treatment of immature necrotic teeth is a problematic situation. Conventional root canal therapy is challenging and leaves a weak, fragile, and undeveloped tooth for lifetime.

Purpose

This review was aimed to assess the outcome of available randomized clinical trials (RCTs) on the efficacy of platelet concentrates (PC) in dentine-pulp complex regeneration.

Materials and Method

In this systematic review, an electronic search was conducted on MEDLINE, EMBASE, Cochrane, and Google scholar databases. A further manual search was performed on the list of related articles in order to ensure inclusion of potentially missed articles in earlier electronic search. Those proved RCTs matched with the standard criteria were included following an initial assessment of abstracts and the text independently by the reviewers.

Results

From the total 602 harvested articles, only 13 met the criteria and were evaluated with 11 having parallel design and 2 split mouth. Only one study featured low risk of bias, while three had moderate risk and the rest were at high risk of bias. Six studies had used platelet rich plasma (PRP), 4 employed platelet rich fibrin (PRF), one utilized injectable platelet rich fibrin (I-PRF), and three used both PRF and PRP for their experimental groups while blood clot (BC) was used as the control group for all. The success rate was reported at 87.3% judged by the absence of pathologic signs and symptoms.

Conclusion

Dentin wall thickening, root lengthening and apex closure were higher in PC groups, however, these differences were not statistically significant in reported studies. It can be concluded that PCs promote the pulp tissue revitalization and continuation of root development. However, a consensus on its potency for true pulp regeneration is yet to be reached.

Mines of cytokine: A treasure trove in pulpal and periapical diseases

Pulpitis is a special disease of dental pulp. It causes localized inflammation, due to various inflammatory mediators such as cytokines and chemokines. These inflammatory mediators are responsible for various reparative and resorptive processes in the dental pulp. The balance between these processes ultimately determines the viability of the tooth. Due to the important properties of various inflammatory markers, the correlation of cytokinin gene expression in various stages of inflammation becomes necessary to focus on. Several studies in the past have focused on the importance of such correlation to help in diagnostic applications. The nature of these inflammatory mediators can help us in diagnostic evaluation. Several attempts have been made to focus on these associations so that it can assist in making clinical decisions effectively. The data available are vast but are the most neglected topic. This review article briefly outlines and summarizes the importance of various inflammatory mediators such as cytokinin and chemokines in various pathways of pulpal and periapical inflammation in explanatory and diagrammatic forms. Knowledge gained about pulpal inflammatory response may aid in understanding the molecular level of inflammatory pulpal and periapical diseases, which shall modify our future diagnostic modalities. Several medicaments are used in the treatment of minimal to advanced dental caries which leads to periapical infections. Thorough understanding of these medicaments can resolve secondary infection and can improve the prognosis of the treated tooth.

Platelet-Rich Fibrin (PRF) and its Application in Dentistry: A Literature Review

Platelet-rich fibrin (PRF) is a biocompatible fibrin matrix that acts as a resorbable membrane, collecting platelet cytokines, growth factors, and cells and releasing them. It is easily extracted from blood. Many dentists use PRF, a concentrated growth factor solution, to treat various lesions and regenerate tooth and oral tissues. This research examines the pros, cons, and suggestions of using PRF in dentistry.

Autologous Concentrate Growth Factor for the Treatment of Endo-Perio Lesion - A Case Report

INTRODUCTION

The success of a combined periodontal and endodontic lesion depends on the elimination of both these disease processes. In the case of a combined endo-perio lesion, endodontic therapy results in healing of the endodontic component of involvement, while the prognosis of teeth would finally depend on the healing of the periodontal structure.

TREATMENT

This case report evaluates the efficacy of autologous fibrin glue and bone graft, that is, sticky bone in the management of bone defects associated with endo-perio lesion. The endo-perio lesion is first treated endodontically, followed by periodontal therapy. Conclusion: The patient was kept on follow-up for 9 months, and satisfactory results in terms of bone fill and reduction in pocket depth were obtained.

TAKEAWAY LESSONS

The sticky bone enhances regeneration in treatment of endo-perio lesions.

Macro, Micro, and Nano-Inspired Bioactive Polymeric Biomaterials in Therapeutic, and Regenerative Orofacial Applications

Introducing dental polymers has accelerated biotechnological research, advancing tissue engineering, biomaterials development, and drug delivery. Polymers have been utilized effectively in dentistry to build dentures and orthodontic equipment and are key components in the composition of numerous restorative materials. Furthermore, dental polymers have the potential to be employed for medication administration and tissue regeneration. To analyze the influence of polymer-based investigations on practical medical trials, it is required to evaluate the research undertaken in this sector. The present review aims to gather evidence on polymer applications in dental, oral, and maxillofacial reconstruction.

Evaluation of postoperative pain and healing following regenerative endodontics using platelet-rich plasma versus conventional endodontic treatment in necrotic mature mandibular molars with chronic periapical periodontitis. A randomized clinical trial

AIM

To evaluate the post-operative pain and the healing of necrotic mature permanent mandibular molar teeth with peri-apical periodontitis after conventional endodontic treatment versus after platelet-rich plasma (PRP) revascularization.

METHODOLOGY

The protocol of this randomized clinical trial was registered at www.

CLINICALTRIALS

gov with identification number NCT03350841. Twenty-eight patients were included in the study after confirming the diagnosis clinically and radiographically. In the first visit, mandibular molar teeth of both groups were mechanically prepared. Double antibiotic paste was prepared and injected then the cavity that was sealed with glass ionomer. At the second visit, the patients were randomized either to control group where standard endodontic treatment was completed by lateral condensation technique or assigned to intervention group where PRP revascularization technique. The degree of spontaneous pain was assessed using numerical rating scale (NRS) pre-operatively, then post-operatively after 6, 12 h and daily for 5 days. Patients were given a placebo to be administrated in case of pain. An analgesic (ibuprofen 400mg) was prescribed in case of persistent pain. Clinical and radiographic healing was assessed after 6 and 12 months. All demographic, baseline and outcome data were collected and statistically analysed.

RESULTS

Regarding the post revascularization/obturation pain, there was no statistically significant difference between severity of pain in the two groups at all time intervals except after 12 h, revascularization group showed statistically significantly higher prevalence of no pain than endodontic treatment group. Regarding the healing; the periapical lesions decrease in size significantly from the pre-operative lesion size in both groups without significant difference between the both groups.

CONCLUSION

Within the limitation of this study, PRP revascularization could be an alternative treatment to root canal treatment but further randomized clinical trials with standardized techniques and long follow up periods are recommended for more reliable results.

Surgical Management of Radicular Cyst With the Application of a Natural Platelet Concentrate: A Case Report

Traumatic dental injuries usually involve the dentoalveolar region, and they readily affect the teeth and their surrounding soft and hard tissues. The common sequelae of traumatic dental injuries lead to pulpal necrosis and apical periodontitis along with cystic changes. The current case report describes the surgical management of a radicular cyst in the periapical region of maxillary incisors and highlights the efficacy of natural platelet concentrate [platelet-rich fibrin (PRF)] used for postoperative healing. A 38-year-old male patient presented to the department with pain and mild swelling in the upper front tooth region. On radiographic examination, a radiolucent periapical lesion was evident in relation to the right maxillary central and lateral incisor. In the maxillary anterior region, root canal therapy was performed, followed by periapical surgery and retrograde filling with mineral trioxide aggregate (MTA), and PRF was placed in the surgical site to initiate the healing at a faster rate. The patient was recalled for follow-ups after 12 weeks, 24 weeks, and 36 weeks; he was found to be asymptomatic, and significant periapical healing was observed in the radiograph with almost adequate bone formation.

Are platelet concentrate scaffolds superior to traditional blood clot scaffolds in regeneration therapy of necrotic immature permanent teeth? A systematic review and meta-analysis

BACKGROUND

The effectiveness of platelet concentrates in promoting root development of necrotic immature permanent teeth is unclear. The present study evaluated whether the platelet concentrate protocol was superior to the traditional blood clot protocol in regeneration therapy.

METHODS

We searched Electronic databases, such as PubMed, Cochrane Library, ClinicalTrials and EMBASE. Randomized controlled trial studies, cohort studies, case-control studies and cross-sectional studies were included, in which platelet-rich concentrates were tested for periapical healing and root development, with the blood clot treatment protocol as the control group. Clinical and radiographic outcomes were considered. Selected articles were assessed for risk of bias. Pooled risk ratios (risk ratio, RR) were calculated for clinical success, responses to cold and electric pulp tests, periapical lesions, apex closure, root lengthening, and thickening of the dentin walls. Subgroup meta-analysis were conducted according to the type of platelet concentrate used.

RESULTS

Of the 1272 screened studies, 13 randomized controlled studies, 2 case-control studies and 1 cohort study were selected, in which 465 immature necrotic permanent teeth, particularly incisors and premolars, were treated. Of these 465 teeth, 457 (98.2%) in both the control and experimental groups remained clinically asymptomatic for the entire study duration, whereas eight (1.8%) showed signs and symptoms of failure, including spontaneous pain, sensitivity to percussion or reinfection. Compared with control teeth, teeth treated with PRP achieved better apical healing than BC group (RR 1.13, 95% CI 1.01-1.26, P = 0.03), and teeth treated with platelet concentrates showed improved apical closure (RR 1.04, 95% CI 0.86-1.25, P = 0.69), root lengthening (RR 1.01, 95% CI 0.74-1.39, P = 0.93), and thickening of the dentin walls (RR 1.35, 95% CI 0.95-1.93, P = 0.09), although these differences were not statistically significant.

CONCLUSIONS

Platelet concentrates can be used as successful scaffolds for regenerative endodontic treatment of necrotic immature permanent teeth, and PRP as a scaffold may achieve better periapical healing of teeth with periapical inflammation, although they did not differ significantly from conventional blood clot scaffolds in development of the root.

Neural Regeneration in Regenerative Endodontic Treatment: An Overview and Current Trends

Pulpal and periapical diseases are the most common dental diseases. The traditional treatment is root canal therapy, which achieves satisfactory therapeutic outcomes-especially for mature permanent teeth. Apexification, pulpotomy, and pulp revascularization are common techniques used for immature permanent teeth to accelerate the development of the root. However, there are obstacles to achieving functional pulp regeneration. Recently, two methods have been proposed based on tissue engineering: stem cell transplantation, and cell homing. One of the goals of functional pulp regeneration is to achieve innervation. Nerves play a vital role in dentin formation, nutrition, sensation, and defense in the pulp. Successful neural regeneration faces tough challenges in both animal studies and clinical trials. Investigation of the regeneration and repair of the nerves in the pulp has become a serious undertaking. In this review, we summarize the current understanding of the key stem cells, signaling molecules, and biomaterials that could promote neural regeneration as part of pulp regeneration. We also discuss the challenges in preclinical or clinical neural regeneration applications to guide deep research in the future.

Comparative Evaluation of Platelet-rich Fibrin and Concentrated Growth Factor as Scaffolds in Regenerative Endodontic Procedure: A Randomized Controlled Clinical Trial

AIM

This randomized controlled trial evaluated the efficacy of platelet-rich fibrin (PRF) and concentrated growth factor (CGF) as scaffolds in the regenerative endodontic procedure (REP) using clinical and radiographic parameters along with cone-beam computed tomographic (CBCT) analysis.

MATERIALS AND METHODS

The apexogenesis procedure was performed in 16 teeth. They were randomly divided into two groups of eight teeth each: group I and group II. In group I PRF was used as the scaffold and in group II CGF was used as the scaffold. They were evaluated for pain, pulpal vitality, tenderness on percussion, and mobility, and also evaluated using digital radiographs at 3, 6, 12, and 18 months interval. The response of the teeth was graded using Chen and Chen criteria. Increase in root length, reduction in the apical foramen dimension, and reduction in periapical lesion volume were evaluated using CBCT scans taken preoperatively and at 18 months.

RESULTS

At the end of 3 months, 50% of teeth without periapical pathology were found to be vital in both groups. At the end of 18 months, 60% of the teeth in both groups showed increase in root length, all teeth showed closure of apical foramen, and reduction in the volume of periapical lesion. However, there was no statistically significant difference between the groups (p < 0.05).

CONCLUSION

The clinical and radiographic features reported in this study revealed that both PRF and CGF act as effective scaffolds in REP for regeneration of pulp-dentin complex with promising results.

CLINICAL SIGNIFICANCE

Apexogenesis by revascularization has not been used regularly for the treatment of nonvital teeth with open apex because the results are not reliable. Since platelet concentrates like PRF and CGF are rich in growth factors; when apexogenesis is performed by REP using these platelet concentrates, desirable results can be achieved in a short duration of time. They also accelerate the healing of periapical lesions present in such cases. With the increased success rate of apexogenesis with REP, many clinicians would prefer to use REPs as a treatment option for teeth with open apex.

Advanced Platelet-rich Fibrin-mediated Regeneration of Necrotic Immature Permanent Teeth: A Clinico-radiographic Observational Study

Aim

The objective of the study was to assess the regenerative potential of advanced platelet-rich fibrin (APRF) in the regenerative treatment of necrotic immature permanent teeth (NIPT) in the maxillary incisor region.

Study design

After institutional review board clearance, 10 children aged between 8 and 14 years with NIPT in the maxillary incisor region undergoing APRF treatment were enrolled in a prospective clinico-radiographic exploratory observational study. Baseline clinical, radiographic, and vitality testing before the start of treatment were noted. Patients were followed up at 3, 6, and 12 months posttreatment.

Results

After 3, 6, and 12 months of follow-up, all patients (100%) showed complete resolution of clinical signs and symptoms. All patients (100%) showed periradicular healing, and 9 out of 10 patients (90%) showed a clear hard tissue bridge formation at various levels in the root canal on postoperative radiographs. None of the patients (0%) showed a positive response to vitality testing.

Conclusion

APRF is a promising biomaterial in regenerative endodontic treatment (RET). Future randomized trials can be planned to establish superiority or equivalence to conventional PRF.

How to cite this article

Wakhloo T, Shukla S, Chug A, et al. Advanced Platelet-rich Fibrin-mediated Regeneration of Necrotic Immature Permanent Teeth: A Clinico-radiographic Observational Study. Int J Clin Pediatr Dent 2022;15(4):402-406.

Effect of citric acid versus ethylenediaminetetraacetic acid on radiographic root development in regenerative endodontic treatment: An animal study

INTRODUCTION

Regenerative endodontic treatment was introduced aiming to reinforce the root and enable further root development. In the process of dentin mineralization, bioactive molecules are entrapped in the dentin matrix, which can be later released by rinsing the dentin with chelating agents. This study aimed to compare the effects of citric acid and ethylenediaminetetraacetic acid (EDTA) on radiographic root development in regenerative endodontic treatment in an animal model.

METHODS

Premolars of three beagle dogs were used in this study. The teeth at one side of the jaw were irrigated with EDTA according to the regeneration protocol of the American Association of Endodontists (AAE). The teeth in the other quadrant were irrigated with citric acid in the second treatment session. Follow-up radiographs were obtained at six months, and the primary and final data were analyzed in SPSS using the Analysis of covariance (ANCOVA).

RESULTS

There was no significant difference between the two irrigating solutions regarding the increase in root length (P=0.668); however, EDTA showed significantly superior efficacy in increasing the root dentin thickness compared with citric acid (P=0.022).

CONCLUSIONS

Within the limitations of this study, the use of citric acid versus EDTA was not superior on radiographic root development in regenerative endodontic treatment.

Platelet-Rich Fibrin Used in Regenerative Endodontics and Dentistry: Current Uses, Limitations, and Future Recommendations for Application

Regenerative endodontics has introduced numerous procedures such as pulp implantation, revascularization, and postnatal stem cell therapy. Revascularization has been successfully implemented clinically nowadays, thus providing dentists with outrageous results. Platelet-rich fibrin (PRF) used either alone or along with bone graft promotes bone growth and vascularization. This matrix promotes migration, cell attachment, and proliferation of osteoblast that leads to bone formation. PRF consists of a packed fibrin complex consisting of leukocytes, cytokines, and glycoproteins such as thrombospondin. The usage of PRF has reported high success rates in surgical cases such as sinus lift procedures, healing of extraction sockets, and management of periapical abscesses. Compared to platelet-rich plasma, PRF is more economical, easy to prepare, and feasible to use in daily clinical practices. Revascularization compromised the induction of a blood clot into the root canal space, which emerged as a clinical triumph. This further led to platelet concentrates as an autologous scaffold on which revascularization could occur. The applications of PRF in regenerative endodontics are numerous, such as an agent for repairing iatrogenic perforation of the pulpal floor and for the revascularization of immature permanent teeth with necrotic pulps. It acts as a matrix for tissue ingrowth. Evidence of progressive thickening of dentinal walls, root lengthening, regression in the periapical lesion, and apical closure was reported. Further studies are needed to clarify the precise mechanism of action of PRF for dental pulp regeneration both in vitro and in vivo. The current review aims at the present uses of PRF in regenerative endodontics dentistry and its application with future recommendations and limitations.

PRP and PRF-Subgroups and Divisions When Used in Dentistry

Blood derivates, such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), are autogenous sources of many growth factors that are involved in the healing and regeneration of tissues, and for this reason, are used in dentistry treatments. This fact also contributes to the growing interest in these biomaterials in regenerative personalized medicine. The multitude of platelet-rich forms creates many possibilities for their use. This semi-systematic review describes and compares the methods of obtaining properties and potential uses of these materials in personalized treatments.

Management of internal inflammatory root resorption using injectable platelet-rich fibrin revascularization technique: a clinical study with cone-beam computed tomography evaluation

OBJECTIVES

The current study evaluated clinically and radiographically the management of internal inflammatory root resorption (IIRR) in permanent anterior teeth with or without periapical lesions using injectable platelet-rich fibrin (i-PRF) regenerative approach.

METHODS

Ten systemically healthy patients, with thirteen anterior mature teeth diagnosed with IIRR were selected for the study. At the first visit, the tooth was anesthetized, access cavity opened, root canals were mechanically prepared then medicated with calcium hydroxide and temporarily sealed. After 2-4 weeks, regenerative endodontic procedures were performed by preparing and applying i-PRF inside the canal, then a freshly prepared PRF membrane was placed over it. White mineral trioxide aggregate was placed over the PRF matrix, and the tooth was restored with a glass ionomer cement base and resin composite restoration. The patients were recalled for clinical and radiographic evaluation and follow-up every 3 months for 12 months. Cone-beam computed tomography (CBCT) imaging was performed preoperatively and after 12 months.

RESULTS

Clinical evaluation results showed resolution of signs and symptoms through the follow-up period in all of the cases. Both CBCT imaging readings of IIRR lesions and periapical lesions revealed a volumetric significant difference (p = 0.00) between the preoperative and the 12-month follow-up period.

CONCLUSIONS

Usage of i-PRF could arrest and allow for healing of IIRR in permanent mature teeth and allow for periapical healing with successful clinical results.

CLINICAL RELEVANCE

i-PRF revascularization technique proved to be a successful REP in the treatment of the IIRR, reducing the number of appointments and increasing patient compliance.

A novel regenerative endodontic procedure in a traumatized immature tooth using amniotic membrane

Tooth nonvitality is one of the frequently seen consequences of dental trauma that causes the arrest of root development. Amniotic membrane has received a lot of attention for its use in transplantation and regeneration procedures. This article reports a unique and novel case of successful regenerative endodontic procedure done using amniotic membrane in a traumatized immature right maxillary central incisor of an 8-year-old girl. The clinical and radiographic evaluation done during the recall visits at 1, 3, 6, 9 and 12 months showed a progressive root growth with apical closure.

Regenerative Endodontic Procedures for the Treatment of Necrotic Mature Teeth with Apical Periodontitis: A Systematic Review and Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Regenerative endodontic procedures (REPs) are intended to repair and regenerate part of the pulp-dentin complex. The aim of this study was to systematically appraise the existing evidence on the effectiveness of REPs on mature teeth with pulp necrosis and apical periodontitis.

METHODS

Electronic database and hand searches were performed on 8 databases of published and unpublished literature from inception to January 3, 2021, for the identification of randomized controlled trials (RCTs) or prospective clinical trials. The related key words included "regenerative," "pulp revascularization," "revitalization procedure," and "necrotic mature teeth." A random effects meta-analysis was conducted assessing success as the main outcome treatment. Risk of bias was assessed through the Cochrane Risk of Bias 2.0 tool, and the quality of the evidence was assessed with the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Of the 337 initial hits, 4 RCTs were eligible for inclusion, whereas 3 were included in the quantitative synthesis. Overall, there was no difference in the relative risk for a successful/unsuccessful treatment outcome between REPs or conventional treatment (3 studies, relative risk = 1.03; 95% confidence interval, 0.92-1.15; P = .61; heterogeneity I² = 0.0%, P = .53; prediction interval = 0.51-2.09). Risk of bias ranged from low to raising some concerns, whereas the quality of the evidence was graded as moderate.

CONCLUSIONS

Based on moderate-quality evidence, REPs appear as a viable treatment alternative for mature necrotic teeth with periapical lesions at present. Furthermore, well-designed RCTs might also provide confirmatory evidence in this respect while also framing a backbone for standardization of the therapeutic protocol of REPs.

Pulp Regeneration in an Immature Maxillary Central Incisor Using Hyaluronic Acid Hydrogel

Pulp regenerative procedure is one of the treatment options for endodontically involved immature permanent teeth. The regenerative endodontic procedure was performed in a child of 9 years. After thorough canal disinfection using triple antibiotic paste for 21 days, bleeding was induced from the apex to provide for the stem cells. After that hyaluronic acid (HA) hydrogel was introduced into the canal space to act as injectable scaffold for pulp regeneration. This was followed by mineral trioxide aggregate placement to provide tight seal from the coronal aspect. Later, the tooth was restored with composite restoration. This approach offers the clinicians great opportunity to physiologically strengthen the immature root walls. The present report presents a regenerative endodontic procedure with HA hydrogel for a traumatized central incisor with arrested root development. The continued root development in the present case suggests that this treatment option may be able to resume the root maturation process in immature teeth with open apices.

Management of necrotic immature permanent maxillary incisors using a modified technique of revascularisation

The management of necrotic immature permanent teeth has always been a challenge to endodontists. Various treatment modalities have been tried and tested for achieving a successful outcome. Revascularisation is one among these treatment options, which is gaining widespread attention among endodontists. The growing body of evidence demonstrating the success of revascularisation has led to different variations of this treatment option. Clinicians have over time used different scaffolds such as blood clot, collagen, platelet-rich fibrin (PRF) and platelet-rich plasma for revascularisation. This case report outlines the management of immature maxillary central incisors with pulp necrosis and large periapical lesions in a 19-year-old female patient with a modified technique of revascularisation by combining PRF and blood clot. At the end of 12 months, the patient was completely asymptomatic along with regression of the periapical lesions.

Improving pulp revascularization outcomes with buccal fat autotransplantation

Several techniques have been introduced to improve the pulp revascularization outcomes. The use of the tissue graft can create more practical tissue regeneration, provide vascular supply, and enhance tissue healing. The aim of the present study was to investigate the histologic and molecular outcomes of pulp revascularization with buccal fat autotransplantation. Fifty-six open apex roots from four dogs aged 4-6 months were randomly allocated to five groups of endodontic regeneration models: Group 1 (negative control, n = 4); Group 2 (control and without intervention, n = 4); Group 3 (blood clot, n = 16); Group 4 (buccal fat autotransplantation, n = 16); and Group 5 (blood clot plus buccal fat autotransplantation, n = 16). After 3 months, the extracted dog teeth were analyzed by histological and immunohistochemical techniques. Furthermore, real-time quantitative polymerase chain reactions were implemented to assess the gene expression profiles of dentin sialophosphoprotein (DSPP), dentin matrix protein (DMP), collagen I (COL1), and alkaline phosphatase (ALP) on regenerated tissue in the root canals. There were no significant differences in the severity of inflammation and necrosis between intervention groups. Immunohistochemical analysis showed significant differences among the study groups in expression level of extracellular glycoproteins such as fibronectin, laminin, and tenascin C. Group 5 showed an increase in the expression of DMP1 and COL1 genes. The expression of DSPP gene increased significantly in Group 4. The expression of ALP gene increased significantly in Group 3. Using this procedure may open new fields of research for regenerative endodontic procedure in which tissue autotransplant, particularly adipose tissue, may improve the outcomes of pulp revascularization.

A Comparative Evaluation of Revascularization Done in Traumatized Immature, Necrotic Anterior Teeth with and without Platelet-rich Fibrin: A Case Report

The aim of this paper is to present two methods of revascularization done in traumatized immature, nonvital anterior teeth using platelet-rich fibrin (PRF) and natural blood clot as a scaffold material. This was performed after disinfection of the root canal space using tri-antibacterial paste. In one tooth, PRF prepared from autologous blood was placed in the canal and in the other tooth, natural bleeding was induced to obtain a fresh blood clot. The patient was recalled regularly at 1, 3, 6, 9, and 12 months’ interval for evaluation. After 12 months, on clinical examination, both teeth showed negative response to percussion and palpation tests but positive response to cold and electric pulp tests. On radiographic examination, the tooth treated with PRF exhibited comparatively faster root lengthening, complete closure of the root apex, more thickening of the root dentinal walls, and narrowing of root canal space compared to conventionally revascularized tooth.

How to cite this article: Nagaveni NB, Poornima P, Mathew MG, et al. A Comparative Evaluation of Revascularization Done in Traumatized Immature, Necrotic Anterior Teeth with and without Platelet-rich Fibrin: A Case Report. Int J Clin Pediatr Dent 2020;13(1):98–102.

Injectable Biomaterials for Dental Tissue Regeneration

Injectable biomaterials scaffolds play a pivotal role for dental tissue regeneration, as such materials are highly applicable in the dental field, particularly when compared to pre-formed scaffolds. The defects in the maxilla-oral area are normally small, confined and sometimes hard to access. This narrative review describes different types of biomaterials for dental tissue regeneration, and also discusses the potential use of nanofibers for dental tissues. Various studies suggest that tissue engineering approaches involving the use of injectable biomaterials have the potential of restoring not only dental tissue function but also their biological purposes.

Polymeric scaffolds for dental pulp tissue engineering: A review

OBJECTIVES

The purpose of this review is to describe recent developments in pulp tissue engineering using scaffolds and/or stem cells. It is crucial to understand how this approach can revitalize damaged dentin-pulp tissue. Widespread scaffold materials, both natural and synthetic, and their fabrication methods, and stem-progenitor cells with the potential of pulp regeneration will be discussed.

DATA AND SOURCES

A review of literature was conducted through online databases, including MEDLINE by using the PubMed search engine, Scopus, and the Cochrane Library.

STUDY SELECTION

Studies were selected based on relevance, with a preference given to recent research, particularly from the past decade.

CONCLUSIONS

The use of biomaterial scaffolds and stem cells can be safe and potent for the regeneration of pulp tissue and re-establishment of tooth vitality. Natural and synthetic polymers have distinct advantages and limitations and in vitro and in vivo testing have produced positive results for cell attachment, proliferation, and angiogenesis. The type of biomaterial used for scaffold fabrication also facilitates stem cell differentiation into odontoblasts and the resulting biochemistry of tissue repair for each polymer and cell type was discussed. Multiple methods of scaffold design exist for pulp tissue engineering, which demonstrates the variability in tissue engineering applications in endodontics. This review explains the potential of evidence-based tissue engineering strategies and outcomes in pulp regeneration.

Comparative Study between Revitalization of Necrotic Immature Permanent Anterior Teeth with and without Platelet Rich Fibrin: A Randomized Controlled Trial

OBJECTIVES

This study was conducted to evaluate the effect of platelet rich fibrin (PRF) during revitalization of necrotic immature permanent anterior teeth after 6 months and 1 year follow up period. The following treatment protocols; Group A: revitalization using blood clot scaffold only, and Group B: revitalization using blood clot and PRF.

STUDY DESIGN

twenty-two patients (7-12 years old) suffering from immature necrotic permanent maxillary central incisors were randomly selected and randomly allocated into 2 groups. Clinical examinations were performed to detect any pain or swelling during the follow up period. Standardized radiographs were digitally evaluated for changes in root length, periapical radiolucency size, presence of apical or cervical calcific bridges.

RESULTS

After a follow-up period of 12 months, most of the cases showed radiographic evidence of periapical healing and showed calcific bridges either cervical and/or apical. No significant differences were shown between both groups.

CONCLUSIONS

The revitalization procedures succeeded to show continued development of roots in teeth with necrotic pulps. The use of PRF was not essential for repair but it helped during the procedures.

Personalized Cell Therapy for Pulpitis Using Autologous Dental Pulp Stem Cells and Leukocyte Platelet-rich Fibrin: A Case Report

INTRODUCTION

Regenerative endodontic procedures have emerged as a new treatment. The aim of this case report was to describe a regenerative autologous cellular therapy using mesenchymal stem cells from inflamed dental pulp and leukocyte platelet-rich fibrin (L-PRF) in a mature tooth.

METHODS

A healthy 50-year-old man consulting for spontaneous dental pain was referred for endodontic treatment in tooth #28, which was diagnosed with symptomatic irreversible pulpitis. Inflamed dental pulp was extracted and transported to a good manufacturing practice laboratory for the isolation and culture of dental pulp stem cells (DPSCs). L-PRF was obtained from the patient's blood and was introduced into the instrumented and disinfected root canal, and expanded DPSCs were inoculated into the clot. The cervical part of the root canal was sealed with Biodentine (Septodont, Saint-Maur-des-Fosses, France) and a composite resin.

RESULTS

Follow-up examinations were performed 6 months and 3 years later. The examinations included periapical radiographs (to measure the periapical index [PAI]), cone-beam computed tomographic (CBCT) imaging, sensitivity, and vitality tests. Clinical evaluations revealed normal responses to percussion and palpation tests. The tooth had a delayed response to cold, and the electric pulp test was responsive. The PAI and CBCT imaging revealed that the periapical area remained normal with a PAI score of 1 and a CBCT PAI score of 0. The vitality test performed indicated low blood perfusion units.

CONCLUSIONS

This case study reveals the potential use of a patient's own DPSCs and L-PRF as an alternative procedure for the treatment of pulpitis in mature permanent teeth. It also paves the way for the design of personalized cell-based clinical trials in regenerative endodontics.

Direct and Indirect Effect of Chlorhexidine on Survival of Stem Cells from the Apical Papilla and Its Neutralization

INTRODUCTION

Several irrigants have been used for disinfection in regenerative endodontic procedures including chlorhexidine (CHX). In this context, the antibacterial properties of disinfectants are mainly in focus of research even though they may have an undesirable impact on the fate of stem cells. In this study, we hypothesized that CHX has both a direct effect when applied to stem cells of the apical papilla (SCAPs) and an indirect effect when SCAPs are exposed to dentin previously conditioned with CHX.

METHODS

Cell toxicity was evaluated in vitro using the CellTox green fluorescence assay (Promega, Madison, WI) and CellTiter-Glo (Promega) after SCAPs were exposed directly to a dynamic concentration range of CHX; apical papilla explant cultures were stained with ApopTag (Merck Millipore, Billerica, MA) after culture with CHX. Furthermore, standardized slabs from human dentin were treated with CHX and consecutively rinsed in EDTA, L-α-lecithin (Sigma-Aldrich, St Louis, MO), or L-α-lecithin followed by EDTA. After that, SCAPs were cultured on the slabs for 5 days, and cellular viability was determined (indirect effect). Data were treated nonparametrically and analyzed using the Krukal-Wallis test (P ≤ .05).

RESULTS

Direct exposure of SCAPs to CHX highly affected cell viability at concentrations above 10^-3%, whereas lower concentrations had no adverse effect. During the initial 60 minutes, concentrations of 10^-2% CHX or higher resulted in early pronounced toxicity with a maximum effect within 15 minutes after exposure. Likewise, CHX-conditioned dentin slabs were detrimental to SCAP survival; however, the deleterious effects were completely reversed by neutralization with L-α-lecithin.

CONCLUSIONS

Chlorhexidine is toxic to SCAPs when applied directly or indirectly via conditioned dentin. If applied for a short time and neutralized by L-α-lecithin, it can be a gentle and cell-preserving disinfectant before endodontic regeneration.

Comparative evaluation of angiogenesis using a novel platelet-rich product: An in vitro study

Background:

In vivo angiogenesis is normal and vital process in growth and development, wound healing, and formation of granulation tissue wherein new blood vessels form from preexisting vessels as part of revascularization. Platelet-rich products promote wound healing associated with angiogenesis. Biomaterials such as titanium were found to be angiogenic. Unlike in vivo situations, in vitro angiogenesis, study cells, within a controlled environment.

Aims:

The aim of this study is to evaluate the angiogenic potential of a novel platelet-rich product.

Materials and Methods:

Blood was drawn from volunteers with informed consent. Blood samples were centrifuged to obtain platelet-rich products. Platelet concentrates prepared were platelet-rich plasma (PRP), platelet-rich fibrin, and a novel platelet-rich product which is titanium-prepared PRP (TPRP), obtained using titanium. The study which compared platelet concentrate was divided into four groups subjected to tissue culture. Phase-contrast microscope was used to determine the rate of growth by cell counting.

Statistical Analysis:

ANOVA was used for comparison within groups and post hoc for multiple comparisons.

Results:

TPRP group showed granular ground substance. Group with platelet-rich fibrin (PRF) shows a high rate of growth whereas those with TPRP showed better growth rate when compared to its counterpart, PRP.

Conclusions:

This is the first study which introduces TPRP. Previous studies have proved that titanium-prepared PRF has better structural quality than its counterpart platelet-rich fibrin. This study concludes that TPRP has better angiogenic potential than its counterpart PRP. Further in vivo studies are needed to promote TPRP as a new generation of platelet products.

Efficacy of Autologous Platelet Concentrates in Regenerative Endodontic Treatment: A Systematic Review of Human Studies

INTRODUCTION

The latest research concerns the use of platelet concentrates, which are introduced into the root canal. The aim of this study was to examine the effectiveness of platelet-rich fibrin and platelet-rich plasma in regenerative endodontics.

METHODS

This literature review was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The literature search included all publications without a year limit. The last search was performed on January 31, 2018. An electronic search was performed using MEDLINE (PubMed), Cochrane, and Scopus. Articles were selected that addressed the following research question: Is the use of platelet concentrates effective in regenerative endodontics? The necessary information was extracted by 2 authors independently using a standardized form.

RESULTS

The search resulted in 426 titles from all databases, and 26 studies met the inclusion criteria. Five were randomized trials, and the others were case reports. All described cases were asymptomatic. Only 3 cases from randomized trials were unsuccessful. Ten of the case reports found positive results for pulp vitality. In randomized trials, the teeth treated with platelet concentrates showed better results for pulp vitality. In almost all cases, they also described thickening and lengthening of the root wall and closure of the apical foramen, which are important for successful treatment of permanent teeth.

CONCLUSIONS

This review showed that procedures using autologous platelet concentrates were successful in treating permanent teeth with root development. However, more long-term clinical studies are needed.

Alternative to Avoid Tooth Discoloration after Regenerative Endodontic Procedure: A Systematic Review

Abstract This systematic review aimed to evaluate whether alternative materials to conventional triple antibiotic paste (TAP - metronidazole, ciprofloxacin, and minocycline) and grey mineral trioxide aggregate (GMTA) could avoid tooth discoloration in teeth submitted to Regenerative Endodontic Procedure (REP). It was also investigated if dental bleaching is able to reverse the color of darkened teeth due to REP. The search was conducted in four databases (Medline via PubMed, Scopus, ISI Web of Science and BVS - Virtual health library), following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The retrieved papers were uploaded in the software EndNoteTM and two reviewers independently selected the studies and extracted the data. Only studies in humans (case reports, case series, clinical trials) were included in the review. From 1,122 potentially eligible studies, 83 were selected for full-text analysis, and 38 were included in the review. The included studies were mainly case reports (76.3 %). The studies described a total of 189 teeth submitted to REP. From these, about 54% of teeth presented some degree of discoloration. Most teeth presenting color alteration were treated with TAP, especially when combined with GMTA. Only three studies performed dental bleaching to restore the color of teeth and neither bleaching technique was able to restore the original color of the crowns. The use of alternative materials to TAP and GMTA, such as double antibiotic paste or Ca(OH)2 pastes and white mineral trioxide aggregate or BiodentineTM, reduces the occurrence of tooth discoloration.

The efficacy of platelet-rich fibrin as a scaffold in regenerative endodontic treatment: a retrospective controlled cohort study

Background

Blood Clot (BC) or platelet concentrates have been used as scaffold in regenerative endodontic treatment (RET). The aim of this retrospective study was to compare the performance of platelet-rich fibrin (PRF) with BC in inducing root development and periapical lesion healing after tooth revascularization.

Methods

Five patients receiving RET using PRF as a scaffold were matched 1:1 to a previous cohort of 5 patients who underwent tooth revascularization by provoking periapical bleeding. Clinical signs and symptoms were examined at follow-ups. Periapical lesion healing and root development were monitored radiographically. The resolution of clinical signs and symptoms as well as periapical radiolucency was observed in all patients (100%).

Results

Root elongation, dentinal wall thickening and apex closure were found in most cases (80% in both groups). There was no significant difference between the groups in terms of clinical sign resolution, root development and periapical healing.

Conclusions

Within the limits of this study, PRF achieved comparable outcomes to BC in terms of clinical sign and symptom resolution, periapical lesion healing and continued root development in RET.

Microbial Modulation of Stem Cells and Future Directions in Regenerative Endodontics

Regenerative endodontic procedures (REPs) have been shown to promote the resolution of signs and symptoms of disease and increase survival compared with traditional treatment procedures. However, there is still variable predictability of continued root development and evidence that the tissues formed do not recapitulate the native pulp-dentin complex. There is growing evidence that the apical papilla is capable of surviving prolonged endodontic infection and apical periodontitis and that it represents a rich source of undifferentiated mesenchymal stem cells in REPs. The survival and proper differentiation of stem cells transferred into infected root canals are fraught with challenges. Residual antigens, such as lipopolysaccharides, have been shown to be present in dentin even after adequate chemomechanical debridement. These antigens have a profound effect on stem cell fate by modulating their proliferative capacity and postdifferentiation phenotype. Thus, root canals must be detoxified in addition to disinfection. There is a strong need for translational studies that incorporate all aspects of tissue engineering in endodontics in models that include an existing infection to promote further advancement of the field. This is particularly important to make REPs more predictable when treating immature teeth in young patients. Importantly, regenerative procedures could eventually promote tooth longevity in our aging population. Lessons learned from translational studies that best mimic the clinical challenges could be evaluated in pragmatic clinical trials to determine the effectiveness of these procedures to promote desirable patient-centered outcomes.

Hyaluronic acid hydrogels incorporating platelet lysate enhance human pulp cell proliferation and differentiation

The restoration of dentine-pulp complex remains a challenge for dentists; nonetheless, it has been poorly addressed. An ideal system should modulate the host response, as well as enable the recruitment, proliferation and differentiation of relevant progenitor cells. Herein was proposed a photocrosslinkable hydrogel system based on hyaluronic acid (HA) and platelet lysate (PL). PL is a cocktail of growth factors (GFs) and cytokines involved in wound healing orchestration, obtained by the cryogenic processing of platelet concentrates, and was expected to provide the HA hydrogels specific biochemical cues to enhance pulp cells' recruitment, proliferation and differentiation. Stable HA hydrogels incorporating PL (HAPL) were prepared after photocrosslinking of methacrylated HA (Met-HA) previously dissolved in PL, triggered by the Ultra Violet activated photoinitiator Irgacure 2959. Both the HAPL and plain HA hydrogels were shown to be able to recruit cells from a cell monolayer of human dental pulp stem cells (hDPSCs) isolated from permanent teeth. The hDPCs were also seeded directly over the hydrogels (5 × 10⁴ cells/hydrogel) and cultured in osteogenic conditions. Cell metabolism and DNA quantification were higher, in all time-points, for PL supplemented hydrogels (p < 0,05). Alkaline phosphatase (ALPL) activity and calcium quantification peaks were observed for the HAPL group at 21 days (p < 0,05). The gene expression for ALPL and COLIA1 was up-regulated at 21 days to HAPL, compared with HA group (p < 0,05). Within the same time point, the gene expression for RUNX2 did not differ between the groups. Overall, data demonstrated that the HA hydrogels incorporating PL increased the cellular metabolism and stimulate the mineralized matrix deposition by hDPSCs, providing clear evidence of the potential of the proposed system for the repair of damaged pulp/dentin tissue and endodontics regeneration.

Regenerative endodontics: a comprehensive review

The European Society of Endodontology and the American Association for Endodontists have released position statements and clinical considerations for regenerative endodontics. There is increasing literature on this field since the initial reports of Iwaya et al. (Dental Traumatology, 17, 2001, 185) and Banchs & Trope (Journal of Endodontics, 30, 2004, 196). Endogenous stem cells from an induced periapical bleeding and scaffolds using blood clot, platelet rich plasma or platelet-rich fibrin have been utilized in regenerative endodontics. This approach has been described as a 'paradigm shift' and considered the first treatment option for immature teeth with pulp necrosis. There are three treatment outcomes of regenerative endodontics; (i) resolution of clinical signs and symptoms; (ii) further root maturation; and (iii) return of neurogenesis. It is known that results are variable for these objectives, and true regeneration of the pulp/dentine complex is not achieved. Repair derived primarily from the periodontal and osseous tissues has been shown histologically. It is hoped that with the concept of tissue engineering, namely stem cells, scaffolds and signalling molecules, that true pulp regeneration is an achievable goal. This review discusses current knowledge as well as future directions for regenerative endodontics. Patient-centred outcomes such as tooth discolouration and possibly more appointments with the potential for adverse effects needs to be discussed with patients and parents. Based on the classification of Cvek (Endodontics and Dental Traumatology, 8, 1992, 45), it is proposed that regenerative endodontics should be considered for teeth with incomplete root formation although teeth with near or complete root formation may be more suited for conventional endodontic therapy or MTA barrier techniques. However, much is still not known about clinical and biological aspects of regenerative endodontics.

The use of platelet-rich fibrin with platelet-rich plasma support meniscal repair surgery

Introduction

Platelet-rich fibrin (PRF) is the only autologous blood product that releases growth factors and has scaffolding properties. We hypothesized that the use of PRF and Platelet-rich plasma (PRP) would improve operative results, including the recovery of function and repaired meniscus.

Materials and Methods

Seventeen patients underwent arthroscopic meniscus repair with PRF and PRP (PRF group) using our novel device for the injection of the PRF into the joint. Another five patients as a control group underwent meniscal repair without PRF and PRP (non-PRF group). The groups were compared in terms of clinical results (Tegner Activity Level Scale, Lysholm Knee Scoring Scale, and International Knee Documentation Committee [IKDC] scores) and changes in magnetic resonance imaging (MRI) findings before surgery and 6 months after surgery.

Results

The Lysholm and IKDC scores improved in all patients postoperatively. However, there was no significant differencies in the postoperative score between the PRF group and the non-PRF group. Follow-up MRI findings did not clearly show improvements.

Conclusions

PRF and PRP are autologous, safe, and cost-effective sources of growth factors. Therefore, we propose a new application of PRF and PRP for autologous transplantation in meniscus repair surgery.

A Comparative Evaluation of Concentrated Growth Factor and Platelet-rich Fibrin on the Proliferation, Migration, and Differentiation of Human Stem Cells of the Apical Papilla

INTRODUCTION

Concentrated growth factor (CGF) is considered to be a natural biomaterial that is better than platelet-rich fibrin (PRF) in bone regeneration, but there is little information acquired in regenerative endodontics. Therefore, the purpose of this study was to evaluate their effects on the proliferation, migration, and differentiation of human stem cells of the apical papilla (SCAPs).

METHODS

CGF- and PRF-conditioned medium were prepared using the freeze-dried method. SCAPs were isolated and identified. The proliferative potential of SCAPs was investigated using the Cell Counting Kit-8 (KeyGen Biotech, Nanjing, China). The migration capacity was analyzed using transwell assays, and the mineralization ability was determined by alizarin red S staining. The expression levels of alkaline phosphatase, bone sialoprotein, dentin matrix protein 1, and dentin sialophosphoprotein were determined by quantitative polymerase chain reaction.

RESULTS

The cultured cells exhibited mesenchymal stem cell characteristics. The growth rate and migratory cell numbers of the CGF and PRF groups were significantly greater than those of the control group. The mineralized areas in the CGF and PRF groups were significantly larger than those in the control group after incubation for 7 days and 14 days. The expression levels of osteogenic/odontoblast-related genes were reduced on day 7, but they were dramatically enhanced on day 14, and the related gene expression levels in the PRF group were higher than those in the CGF group.

CONCLUSIONS

Both CGF and PRF can promote the proliferation, migration, and differentiation of SCAPs. CGF may be a promising alternative in regenerative endodontics.

Effect of Platelet-rich Fibrin on Odontoblastic Differentiation in Human Dental Pulp Cells Exposed to Lipopolysaccharide

INTRODUCTION

Platelet-rich fibrin (PRF), as an autologous fibrin matrix, is known to contain platelets, leukocytes, and growth factors to control inflammation and to facilitate the healing process. The purpose of this study was to investigate the effects of PRF on odontoblastic differentiation in human dental pulp cells (HDPCs) treated with lipopolysaccharide (LPS).

METHODS

Gene expression of inflammatory cytokines and adhesion molecules on the HDPCs cultured with or without LPS and PRF extract (PRFe) were evaluated by reverse-transcription polymerase chain reaction and Western blot analysis. In addition, odontoblastic differentiation was determined by measuring alkaline phosphatase (ALP) activity using ALP staining, the expression of odontogenesis-related genes, and the extent of mineralization using alizarin red S staining.

RESULTS

Treatment with PRFe significantly attenuated the LPS-stimulated expression of interleukin (IL)-1β, IL-6, and IL-8 in HDPCs. In addition, PRFe inhibited the up-regulation of vascular cell adhesion molecule 1 and the production of intracellular adhesion molecule 1 in HDPCs exposed to LPS. Expression of dentin sialophosphoprotein and dentin matrix acidic phosphoprotein 1, ALP activity, and mineralization were enhanced by PRFe in LPS-treated HDPCs.

CONCLUSIONS

These results suggest that PRF has effects associated not only with inhibition of inflammation in HDPCs exposed to LPS but also stimulation of odontoblastic differentiation.

Comparison of the Effect of PRP, PRF and Induced Bleeding in the Revascularization of Teeth with Necrotic Pulp and Open Apex: A Triple Blind Randomized Clinical Trial

INTRODUCTION

Treatment of a tooth with necrotic pulp and open apex is a special challenge to the clinicians. Apexification with calcium hydroxide and MTA barrier technique fails to induce continued root maturation which makes the tooth susceptible to root fracture. Hence, an ideal outcome for such a tooth should be regeneration of pulp like tissue into the root canal capable of continuing normal root maturation.

AIM

This study aims to compare the effect of Platelet Rich Fibrin (PRF), induced bleeding technique and Platelet Rich Plasma (PRP) in the revascularization of tooth with necrotic pulp and open apex. The main objectives of the study were to: (a) Radiographically evaluate the continuation of root development, increase in the dentin wall thickness and narrowing of canal space, apical closure and resolution of the periapical lesion; and to (b) To clinically evaluate the response to pulp sensibility testing and response to percussion and palpation tests.

MATERIALS AND METHODS

Sixty patients (6 to 28 years) with necrotic immature permanent tooth were randomly categorised into three groups after the root canal disinfection procedure. PRF as scaffolding material (Group A: n=20), revascularization with conventional induced bleeding technique (Group B: n=20), and PRP as the biomaterial (Group C: n=20). The primary outcome variable was measured using Periapical Index (PAI) (for periapical healing), Chen and Chen index (for apical responses), Schei's ruler (for root lengthening and root thickening) and other clinical parameters. The Chi-square test was used to interpret the data among the three groups at the end of 12 months for the variables root lengthening and lateral wall thickness. ANOVA test was performed to compare the mean of the PAI scores of the three groups at preoperative stage and 12 months. If statistically significant, Bonferroni test was done to compare the outcome among the three groups. The significant level was set at p<0.05. Kappa agreement was used to see whether the clinical criteria of success (asymptomatic) were in agreement with radiographic criteria.

RESULTS

At the end of 12 months, patients presented with no pain and no signs of reinfection or no radiographic enlargement of the pre-existing apical pathosis in all the three groups. PRP was better than PRF and induced bleeding technique with respect to periapical wound healing when used in the regenerative endodontic procedures. The groups were comparable on grounds of root lengthening and lateral wall thickening. Type 3 apical response was the most common apical response in all the three groups.

CONCLUSION

On analysing the pros and cons of the techniques performed, it is wise to establish induced bleeding technique as the standard endodontic procedure for revascularization of a non vital immature permanent tooth.

Regenerative Endodontic Procedures: Clinical Outcomes

Immature teeth are at risk for pulp necrosis, resulting in arrested root development and poor long-term prognosis. There is growing evidence that regenerative endodontic procedures promote desirable clinical outcomes. Despite significant advances in the field of regenerative endodontics and acceptable clinical outcomes, current evidence suggests that the tissues formed following currently used procedures do not completely recapitulate the former pulp-dentin complex. Further research is needed to identify prognostic factors and predictors of successful outcomes and to develop different treatment strategies to better predictably achieve all identified clinical outcomes, while favoring tissue formation that more closely resembles the pulp-dentin complex.