An innovative cell-based transplantation therapy for an immature permanent tooth in an adult: a case report.

BACKGROUND: Immature teeth with necrotic pulps present multiple challenges to clinicians. In such cases, regenerative endodontic procedures (REPs) may be a favorable strategy. Cells, biomaterial scaffolds, and signaling molecules are three key elements of REPs. Autologous human dental pulp cells (hDPCs) play an important role in pulp regeneration. In addition, autologous platelet concentrates (APCs) have recently been demonstrated as effective biomaterial scaffolds in regenerative dentistry, whereas the latest generation of APCs-concentrated growth factor (CGF), especially liquid phase CGF (LPCGF)-has rarely been reported in REPs. CASE PRESENTATION: A 31-year-old woman presented to our clinic with the chief complaint of occlusion discomfort in the left mandibular posterior region for the past 5 years. Tooth #35 showed no pulp vitality and had a periodontal lesion, and radiographic examination revealed that the tooth exhibited extensive periapical radiolucency with an immature apex and thin dentin walls. REP was implemented via transplantation of autologous hDPCs with the aid of LPCGF. The periodontal lesion was managed with simultaneous periodontal surgery. After the treatment, the tooth was free of any clinical symptoms and showed positive results in thermal and electric pulp tests at 6- and 12-month follow-ups. At 12-month follow-up, radiographic evidence and three-dimensional models, which were reconstructed using Mimics software based on cone-beam computed tomography, synergistically confirmed bone augmentation and continued root development, indicating complete disappearance of the periapical radiolucency, slight lengthening of the root, evident thickening of the canal walls, and closure of the apex. CONCLUSION: hDPCs combined with LPCGF represents an innovative and effective strategy for cell-based regenerative endodontics.

Deciduous pulp tissue implantation into the root canal of mandibular incisor resulted in pulp revascularization: a case report with a 5-year follow-up.

To explore a new method to implant deciduous tooth pulp into the canal of young permanent teeth with necrotic pulps and apical periodontitis for the regenerative endodontic treatment of tooth no: 41 in a 7-year-old male. Briefly, 1.5% Sodium Hypochlorite (NaOCl) irrigation and calcium hydroxide-iodoform paste were used as root canal disinfectant at the first visit. After 2 weeks, the intracanal medication was removed, and the root canal was slowly rinsed with 17% Ethylene Diamine Tetraacetic Acid (EDTA), followed by flushing with 20 mL saline and then drying with paper points. Tooth no: 72 was extracted, and its pulp was extracted and subsequently implanted into the disinfected root canal along with induced apical bleeding. Calcium hydroxide iodoform paste was gently placed over the bleeding clot, and after forming a mineral trioxide aggregate (MTA) coronal barrier, the accessed cavities were restored using Z350 resin composite. The root developments were evaluated via radiographic imaging at 6 months, 1 year and 5 years after treatment. Imaging and clinical analysis showed closure of the apical foramen, thickening of the root canal wall, and satisfactory root length growth. Autologous transplantation might be useful to regenerate dental pulp in necrotic young permanent teeth.

GelMA-based hydrogel biomaterial scaffold: A versatile platform for regenerative endodontics.

Endodontic therapy, while generally successful, is primarily limited to mature teeth, hence the pressing need to explore regenerative approaches. Gelatin methacryloyl (GelMA) hydrogels have emerged as pivotal biomaterials, promising a bright future for dental pulp regeneration. Despite advancements in tissue engineering and biomaterials, achieving true pulp tissue regeneration remains a formidable task. GelMA stands out for its injectability, rapid gelation, and excellent biocompatibility, serving as the cornerstone of scaffold materials. In the pursuit of dental pulp regeneration, GelMA holds significant potential, facilitating the delivery of stem cells, growth factors, and other vital substances crucial for tissue repair. Presently, in the field of dental pulp regeneration, researchers have been diligently utilizing GelMA hydrogels as engineering scaffolds to transport various effective substances to promote pulp regeneration. However, existing research is relatively scattered and lacks comprehensive reviews and summaries. Therefore, the primary objective of this article is to elucidate the application of GelMA hydrogels as regenerative scaffolds in this field, thereby providing clear direction for future researchers. Additionally, this article provides a comprehensive discussion on the synthesis, characterization, and application of GelMA hydrogels in root canal therapy regeneration. Furthermore, it offers new application strategies and profound insights into future challenges, such as optimizing GelMA formulations to mimic the complex microenvironment of pulp tissue and enhancing its integration with host tissues.

Comparative effects of 17% ethylenediaminetetraacetic acid and 9% etidronic acid applied with different irrigant activation techniques on the release of growth factors from dentin: in vitro study.

BACKGROUND: Growth factors embedded in the extracellular matrix of the dentin play an important role in the migration, proliferation, and differentiation of dental pulp stem cells in regenerative endodontics. In regenerative endodontic treatments, the type of irrigation solution used is crucial for the release of growth factors (GFs) from the dentin matrix. This study evaluated the effectiveness of different irrigant activation techniques (IAT) using two different chelating agents, 17% ethylenediaminetetraacetic acid (EDTA) and 9% etidronic acid (HEDP), in terms of their GF release. METHODS: Seventy-two mandibular premolar teeth were prepared to simulate an open apex. The root fragments were irrigated with 20 ml of 1.5% sodium hypochlorite and 20 ml of saline solution. Eight root fragments were randomly separated for the control group, and the remaining 64 fragments were randomly separated into eight groups based on two different chelating agents (17% EDTA and 9% HEDP) and four different IAT ((conventional needle irrigation (CNI), passive ultrasonic irrigation (PUI), sonic activation with EDDY, and XP-endo Finisher (XPF)). TGF-ß1, VEGF-A, BMP-7 and IGF-1 release levels were determined using an ELISA, and statistical analysis was performed using the Kolmogorov-Smirnov test, ANOVA, and the Tukey test (p < .05). RESULTS: Compared to the control group, the experimental groups showed significantly higher GF release when using EDTA or HEDP. Among the activation groups, the EDDY group triggered the highest GF release, and the CNI group triggered the lowest. CONCLUSIONS: IAT with EDTA and HEDP can increase GF release, with EDDY being the most effective IAT method. Using chelating agents with IAT may be beneficial in regenerative endodontic treatments.

Understanding the multi-functionality and tissue-specificity of decellularized dental pulp matrix hydrogels for endodontic regeneration.

Dental pulp is the only soft tissue in the tooth which plays a crucial role in maintaining intrinsic multi-functional behaviors of the dentin-pulp complex. Nevertheless, the restoration of fully functional pulps after pulpitis or pulp necrosis, termed endodontic regeneration, remained a major challenge for decades. Therefore, a bioactive and in-situ injectable biomaterial is highly desired for tissue-engineered pulp regeneration. Herein, a decellularized matrix hydrogel derived from porcine dental pulps (pDDPM-G) was prepared and characterized through systematic comparison against the porcine decellularized nerve matrix hydrogel (pDNM-G). The pDDPM-G not only exhibited superior capabilities in facilitating multi-directional differentiation of dental pulp stem cells (DPSCs) during 3D culture, but also promoted regeneration of pulp-like tissues after DPSCs encapsulation and transplantation. Further comparative proteomic and transcriptome analyses revealed the differential compositions and potential mechanisms that endow the pDDPM-G with highly tissue-specific properties. Finally, it was realized that the abundant tenascin C (TNC) in pDDPM served as key factor responsible for the activation of Notch signaling cascades and promoted DPSCs odontoblastic differentiation. Overall, it is believed that pDDPM-G is a sort of multi-functional and tissue-specific hydrogel-based material that holds great promise in endodontic regeneration and clinical translation. STATEMENT OF SIGNIFICANCE: Functional hydrogel-based biomaterials are highly desirable for endodontic regeneration treatments. Decellularized extracellular matrix (dECM) preserves most extracellular matrix components of its native tissue, exhibiting unique advantages in promoting tissue regeneration and functional restoration. In this study, we prepared a porcine dental pulp-derived dECM hydrogel (pDDPM-G), which exhibited superior performance in promoting odontogenesis, angiogenesis, and neurogenesis of the regenerating pulp-like tissue, further showed its tissue-specificity compared to the peripheral nerve-derived dECM hydrogel. In-depth proteomic and transcriptomic analyses revealed that the activation of tenascin C-Notch axis played an important role in facilitating odontogenic regeneration. This biomaterial-based study validated the great potential of the dental pulp-specific pDDPM-G for clinical applications, and provides a springboard for research strategies in ECM-related regenerative medicine.

Impact of using XP-endo finisher and nanobubble water during EDTA dentin conditioning on TGF-ß1 release in regenerative endodontic procedures.

INTRODUCTION: Transforming Growth Factor-Beta 1 (TGF-ß1) plays a crucial role in the success of Regenerative Endodontic Procedures (REPs) as they directly impact the proliferation and differentiation of stem cells. TGF-ß1 is released by conditioning of the dentin matrix using 17% EDTA. EDTA was found to have deleterious effects on dentin especially in immature teeth with fragile dentin walls. Decreasing the irrigation time was reported to decrease these effects. Accordingly, enhancement and activation of the EDTA solution to maintain its efficiency in TGF-ß1 release from dentin and thus compensating the reduction in irrigation time was employed. EDTA solution was enhanced by adding Nanobubble (NB) water which contains oxygen filled cavities less than 200 nm in diameter. Additionally, EDTA was activated with XP-endo Finisher rotary file. The aim of this study was to assess the impact of NB enhancement and/or XP-endo Finisher activation of the EDTA solution on the TGF-ß1 release from dentin. METHODS: Fifty standardized root segments with open apex were allocated to two main groups according to whether EDTA was enhanced with NB water or not, and within each group whether XP-endo Finisher activation was used or not in addition to a Negative Control group. The concentration of the released TGF-ß1 in the root canal was measured using enzyme-linked immunosorbent assay (ELISA). The statistical analysis was done using the Shapiro- Wilk, Kolmogorov Smirnov, ANOVA and Post-hoc Tukey tests. RESULTS: All groups released a considerable amount of TGF-ß1 with the highest values in the EDTA/NB/XP group, followed by EDTA/NB, EDTA/DW/XP, EDTA/DW and Negative Control groups respectively. CONCLUSIONS: The results of this study suggest that NBs can promote the success of REPs since it revealed a significant increase in the TGF-ß1 release following its use in the enhancement of the EDTA solution. A comparable effect was obtained by XP-endo finisher activation of the EDTA solution. The combined use of NBs and XP-endo Finisher can be a promising addition in REPs. Accordingly, Enhancement and activation of the EDTA solution may compensate decreasing the EDTA irrigation time attempted to avoid the deleterious effect of EDTA on dentin.

Can a dentin bonding agent prevent color change in regenerative endodontic procedures? An in vitro evaluation.

This in vitro study aimed to determine the efficacy of dentin bonding agents in preventing color changes following Regenerative Endodontic Procedures. One hundred twenty bovine incisors were endodontically prepared and randomly assigned to a two main factors design: application of a dentin bonding agent (Scotchbond Adper, 3M ESPE, St Paul, MN, USA) in the pulp chamber (Group 1, n=60) versus no bonding intervention (Group 2, n=60), and five levels of intracanal medication (n=12/subgroup): Triple antibiotic paste (TAP), double antibiotic paste (DAB), calcium hydroxide (CH), modified triple antibiotic paste (TAPM), and Control (CTL). Color changes were measured over 28 days at multiple time points (1, 3, 7, 14, 21, and 28 days) using the CIEDE2000 formula to calculate the color difference (ΔE00) from baseline (T0). The ΔE00 quantifies the perceptible color difference between the initial and final tooth color, with lower values indicating less discoloration. The results were analyzed using repeated measures ANOVA-2 and post-hoc Holm-Sidak tests. The TAP subgroups, both with and without the bonding agent, exhibited the highest color variation. However, a pulp chamber seal with a bonding agent showed a protective effect against discoloration compared to no seal, even though complete prevention was not achieved. All groups demonstrated ΔE00 values beyond acceptable interpretation thresholds for clinical application, primarily driven by a reduction in lightness (L*) and a decrease in redness (a* value, shifting towards green). In conclusion, while the pulp chamber seal with a bonding agent mitigated TAP-induced discoloration, it did not eliminate it.

Influence of extracellular matrix scaffolds on histological outcomes of regenerative endodontics in experimental animal models: a systematic review.

BACKGROUND: Decellularized extracellular matrix (dECM) from several tissue sources has been proposed as a promising alternative to conventional scaffolds used in regenerative endodontic procedures (REPs). This systematic review aimed to evaluate the histological outcomes of studies utilizing dECM-derived scaffolds for REPs and to analyse the contributing factors that might influence the nature of regenerated tissues. METHODS: The PRISMA 2020 guidelines were used. A search of articles published until April 2024 was conducted in Google Scholar, Scopus, PubMed and Web of Science databases. Additional records were manually searched in major endodontic journals. Original articles including histological results of dECM in REPs and in-vivo studies were included while reviews, in-vitro studies and clinical trials were excluded. The quality assessment of the included studies was analysed using the ARRIVE guidelines. Risk of Bias assessment was done using the (SYRCLE) risk of bias tool. RESULTS: Out of the 387 studies obtained, 17 studies were included for analysis. In most studies, when used as scaffolds with or without exogenous cells, dECM showed the potential to enhance angiogenesis, dentinogenesis and to regenerate pulp-like and dentin-like tissues. However, the included studies showed heterogeneity of decellularization methods, animal models, scaffold source, form and delivery, as well as high risk of bias and average quality of evidence. DISCUSSION: Decellularized ECM-derived scaffolds could offer a potential off-the-shelf scaffold for dentin-pulp regeneration in REPs. However, due to the methodological heterogeneity and the average quality of the studies included in this review, the overall effectiveness of decellularized ECM-derived scaffolds is still unclear. More standardized preclinical research is needed as well as well-constructed clinical trials to prove the efficacy of these scaffolds for clinical translation. OTHER: The protocol was registered in PROSPERO database #CRD42023433026. This review was funded by the Science, Technology and Innovation Funding Authority (STDF) under grant number (44426).

Exosomes as Promising Therapeutic Tools for Regenerative Endodontic Therapy.

Pulpitis is a common and frequent disease in dental clinics. Although vital pulp therapy and root canal treatment can stop the progression of inflammation, they do not allow for genuine structural regeneration and functional reconstruction of the pulp-dentin complex. In recent years, with the development of tissue engineering and regenerative medicine, research on stem cell-based regenerative endodontic therapy (RET) has achieved satisfactory preliminary results, significantly enhancing its clinical translational prospects. As one of the crucial paracrine effectors, the roles and functions of exosomes in pulp-dentin complex regeneration have gained considerable attention. Due to their advantages of cost-effectiveness, extensive sources, favorable biocompatibility, and high safety, exosomes are considered promising therapeutic tools to promote dental pulp regeneration. Accordingly, in this article, we first focus on the biological properties of exosomes, including their biogenesis, uptake, isolation, and characterization. Then, from the perspectives of cell proliferation, migration, odontogenesis, angiogenesis, and neurogenesis, we aim to reveal the roles and mechanisms of exosomes involved in regenerative endodontics. Lastly, immense efforts are made to illustrate the clinical strategies and influencing factors of exosomes applied in dental pulp regeneration, such as types of parental cells, culture conditions of parent cells, exosome concentrations, and scaffold materials, in an attempt to lay a solid foundation for exploring and facilitating the therapeutic strategy of exosome-based regenerative endodontic procedures.

Does the use of different scaffolds have an impact on the therapeutic efficacy of regenerative endodontic procedures? A systematic evaluation and meta-analysis.

BACKGROUND: In the regenerative endodontic procedures, scaffolds could influence the prognosis of affected teeth. Currently, there is controversy regarding the postoperative evaluation of various scaffolds for pulp regeneration. The objective of this study was to access whether other scaffolds, used alone or in combination with blood clot (BC), are more effective than BC in regenerative endodontic procedures. METHODS: We systematically search the PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), Embase, and Google Scholar databases. Randomized controlled trials examining the use of BC and other scaffold materials in the regenerative endodontic procedures were included. A random effects model was used for the meta-analysis. The GRADE method was used to determine the quality of the evidence. RESULTS: We screened 168 RCTs related to young permanent tooth pulp necrosis through electronic and manual retrieval. A total of 28 RCTs were related to regenerative endodontic procedures. Ultimately, 12 articles met the inclusion criteria and were included in the relevant meta-analysis. Only 2 studies were assessed to have a low risk of bias. High quality evidence indicated that there was no statistically significant difference in the success rate between the two groups (RR=0.99, 95% CI=0.96 to 1.03; 434 participants, 12 studies); low-quality evidence indicated that there was no statistically significant difference in the increase in root length or root canal wall thickness between the two groups. Medium quality evidence indicated that there was no statistically significant difference in pulp vitality testing between the two groups. CONCLUSIONS: For clinical regenerative endodontic procedures, the most commonly used scaffolds include BC, PRP, and PRF. All the different scaffolds had fairly high clinical success rates, and the difference was not significant. For regenerative endodontic procedures involving young permanent teeth with pulp necrosis, clinical practitioners could choose a reasonable scaffold considering the conditions of the equipment and patients.

Characterization of cells in blood evoked from periapical tissues in immature teeth with pulp necrosis and their potential for autologous cell therapy in Regenerative Endodontics.

OBJECTIVE: The objectives of this study were to isolate, characterize progenitor cells from blood in the root canals of necrotic immature permanent teeth evoked from periapical tissues and evaluate the applicable potential of these isolated cells in Regenerative Endodontics. DESIGN: Ten necrotic immature permanent teeth from seven patients were included. Evoked bleeding from periapical tissues was induced after chemical instrumentation of the root canals. Cells were isolated from the canal blood and evaluated for cell surface marker expression, multilineage differentiation potential, proliferation ability, and target protein expression. Cell sheets formed from these cells were transferred into human root segments, and then transplanted into nude mice. Histological examination was performed after eight weeks. Data analysis was conducted using one-way ANOVA followed by Tukey's post-hoc comparison, considering p < 0.05 as statistically significant. RESULTS: The isolated cells exhibited characteristics typical of fibroblastic cells with colony-forming efficiency, and displayed Ki67 positivity and robust proliferation. Flow cytometry data demonstrated that at passage 3, these cells were positive for CD73, CD90, CD105, CD146, and negative for CD34 and CD45. Vimentin expression indicated a mesenchymal origin. Under differentiation media specific differentiation media, the cells demonstrated osteogenic, adipogenic, and chondrogenic differentiation potential. Subcutaneous root canals with cell sheets of isolated cells in nude mice showed the formation of pulp-like tissues. CONCLUSIONS: This study confirmed the presence of progenitor cells in root canals following evoked bleeding from periapical tissues of necrotic immature teeth. Isolated cells exhibited similar immunophenotype and regenerative potential with dental mesenchymal stromal cells in regenerative endodontic therapy.

Correlation between pulp sensibility and magnetic resonance signal intensity following regenerative endodontic procedures in mature necrotic teeth- a retrospective cohort study.

BACKGROUND: With increasing studies being published on regenerative endodontic procedures (REPs) as a treatment modality for mature necrotic teeth, the assessment of outcomes following regenerative endodontic procedures has become more challenging and the demand for a better understanding of the regenerated tissues following this treatment is rising. The study aimed to correlate cold, electric pulp testing (EPT), and magnetic resonance imaging (MRI) signal intensity (SI) in mature necrotic teeth treated with regenerative endodontic procedures. METHODOLOGY: This retrospective cohort study included eighteen adult patients who experienced tooth necrosis in mature maxillary anterior teeth recruited from the outpatient clinic, Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Alexandria, Egypt from July 2017 until December 2018 with 12 months of follow-up. regenerative endodontic procedures via blood clot were performed. The canals were instrumented by ProTaper Next (PTN) files until final sizes X3 or X5. Biodentine was used as cervical plug material. Pre and post-operative clinical follow-up was done where the patients' responses to cold and electric pulp testing were given a scoring system and were compared to the normal contralateral tooth. Pre and post-operative magnetic resonance imaging signal intensity of both the involved tooth and its contralateral at the middle and the apical thirds of the root canals were assessed after 3, 6, and 12 months. Data was analyzed using the ANOVA, Friedman and Bonferroni tests. Significance was set at a p-value < 0.05. RESULTS: All 18 teeth scored a baseline score of "2" for cold and electric pulp testing. There was a significant difference between scores of the cold test at baseline and 12-month follow-up (p < 0.001). There was a significant difference between scores of the electric pulp testing of baseline and 12-month follow-up (p < 0.001). There was a moderately significant indirect (inverse) correlation between magnetic resonance imaging signal intensity and cold test in both the middle and apical thirds at 12 months. No significant correlations were detected between magnetic resonance imaging signal intensity and electric pulp testingat any of the time intervals (p > 0.05). CONCLUSION: Magnetic resonance imaging is a successful non-invasive method to assess outcomes of regenerative endodontic procedures and correlating it with another reliable method of assessing pulpal responses, cold test, could validate these outcomes. CLINICAL TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov (ID: NCT03804450).

Failed Regenerative Endodontic Case Treated by Modified Aspiration-irrigation Technique and Apexification.

AIM: This report addresses the management of a large persistent discharging lesion in an 11-year-old boy. The report describes the use of aspiration-irrigation technique for the management of immature necrotic tooth with persistent discharge after a failed regenerative procedure. BACKGROUND: Regenerative endodontics aim to provide an increase in root canal width, length, and in apical closure. Alternative procedures, such as apexification, should be attempted when regeneration fails. If the canal cannot be dried to persistent discharge, the aspiration-irrigation technique can be used. The technique relies on using aspiration along with irrigation to remove pus from the periapical area. CASE DESCRIPTION: This is a case for an 11-year-old patient who had trauma to tooth #11, which resulted in the complicated crown fracture. He had an emergency management that included pulpectomy and intracanal medication at another clinic. Two years later, the patient was presented to our clinic. Upon examination, the diagnosis was previously initiated therapy with asymptomatic apical periodontitis in immature tooth #11. Regeneration was attempted first but failed. The mineral trioxide aggregate (MTA) plug was removed, and the canal had persistent pus discharge. The canal was filled with intracanal medication, and then 2 weeks later, the canal was filled with triple antibiotic paste (TAP). Next visit, and due to continuous discharge, tooth #11 was treated conservatively with an intracanal aspiration-irrigation technique. An IrriFlex needle attached to a high-volume suction was used to aspirate the cystic fluid. Mineral trioxide aggregate plug apexification was performed in a later visit and the tooth was restored. CONCLUSION: During the 3-month and 16-month follow-up, there was resolution of the symptoms, a decrease in the periapical lesion size, and soft tissues appeared within normal limits. CLINICAL SIGNIFICANCE: Regenerative procedures are a good option for immature necrotic teeth. These procedures may fail due to persistent pus discharge from the root canals. The aspiration-irrigation technique is a good treatment option in cases of consciously discharging canals. How to cite this article: Alsofi L, Almarzouki S. Failed Regenerative Endodontic Case Treated by Modified Aspiration-irrigation Technique and Apexification. J Contemp Dent Pract 2024;25(1):92-97.

Final irrigation with bioglass solution in regenerative endodontic procedure induces tissue formation inside the root canals, collagen maturation, proliferation cell and presence of osteocalcin.

AIM: To evaluate the influence of an experimental solution of cobalt-doped F18 bioactive glass (F18Co) on tissue repair following regenerative endodontic procedure (REP) in rat molars. METHODOLOGY: The F18Co solution was prepared at a ratio of 1:5 F18Co powder to distilled water. The right or left upper first molars of 12 Wistar rats were used, where the pulps were exposed, removed, and irrigated with 2.5% sodium hypochlorite (NaOCl), followed by 17% ethylenediaminetetraacetic acid (EDTA) (5 min each). Subsequently, the molars were divided into two groups (n = 6): REP-SS and REP-F18Co, where they received a final irrigation (5 min) with saline solution (SS) or F18Co solution, respectively. Then, intracanal bleeding was induced, and the tooth was sealed. Untreated molars were used as controls (n = 3). At 21 days, the rats were euthanized, and the specimens were processed for analysis of mineralized tissue and soft tissue formation inside the root canal using haematoxylin-eosin. The presence and maturation of collagen were evaluated by Masson's trichrome and picrosirius red staining. Immunolabelling analyses of proliferating cell nuclear antigen (PCNA) and osteocalcin (OCN) were performed. The data were submitted to the Mann-Whitney U-test (p < .05). RESULTS: There was a similar formation of mineralized tissue in thickness and length in REP-SS and REP-F18Co groups (p > .05). Regarding the presence of newly formed soft tissue, most specimens of the REP-F18Co had tissue formation up to the cervical third of the canal, whilst the REP-SS specimens showed formation up to the middle third (p < .05), and there was higher maturation of collagen in REP-F18Co (p < .05). The number of PCNA-positive cells found in the apical third of the root canal was significantly higher in the F18Co group, as well as the OCN immunolabelling, which was severe in most specimens of REP-F18Co, and low in most specimens of REP-SS. CONCLUSION: The final irrigation with F18Co bioactive glass solution in REP did not influence mineralized tissue formation but induced soft tissue formation inside the root canals, with higher collagen maturation, and an increase in PCNA-positive cells and OCN immunolabelling.

Dental Pulp Cell Transplantation Combined with Regenerative Endodontic Procedures Promotes Dentin Matrix Formation in Mature Mouse Molars.

Regenerative endodontic procedures (REPs) are promising for dental pulp tissue regeneration; however, their application in permanent teeth remains challenging. We assessed the potential combination of an REP and local dental pulp cell (DPC) transplantation in the mature molars of C57BL/6 mice with (REP + DPC group) or without (REP group) transplantation of DPCs from green fluorescent protein (GFP) transgenic mice. After 4 weeks, the regenerated tissue was evaluated by micro-computed tomography and histological analyses to detect odontoblasts, vasculogenesis, and neurogenesis. DPCs were assessed for mesenchymal and pluripotency markers. Four weeks after the REP, the molars showed no signs of periapical lesions, and both the REP and REP + DPC groups exhibited a pulp-like tissue composed of a cellular matrix with vessels surrounded by an eosin-stained acellular matrix that resembled hard tissue. However, the REP + DPC group had a broader cellular matrix and uniquely contained odontoblast-like cells co-expressing GFP. Vasculogenesis and neurogenesis were detected in both groups, with the former being more prominent in the REP + DPC group. Overall, the REP was achieved in mature mouse molars and DPC transplantation improved the outcomes by inducing the formation of odontoblast-like cells and greater vasculogenesis.

Revolutionizing Endodontics: Innovative Approaches for Treating Mature Teeth With Closed Apices and Apical Lesions: A Report of Two Cases.

INTRODUCTION: Modern tissue engineering strategies have elucidated the potential of regenerative endodontic treatment (RET) as an alternative for treating mature teeth. METHODS: Here, we report two cases in which cell-based RET (CB-RET) using encapsulated allogeneic umbilical cord mesenchymal stem cells (UC-MSCs) in a platelet-poor plasma (PPP)-based scaffold was used in two mature teeth with pulp necrosis and apical periodontitis. RESULTS: After 5 years of follow-up, the healing response was satisfactory in both cases, with evidence of pulp revitalization. CONCLUSIONS: This is the first study to report the success of an extended, 5-year follow-up for allogeneic CB-RET. This report presents an innovative and sustainable solution to challenging endodontic scenarios.

In vitro and in vivo evaluation of iRoot BP Plus as a coronal sealing material for regenerative endodontic procedures.

OBJECTIVES: To investigate in vitro effects of a nanoparticle bioceramic material, iRoot BP Plus, on stem cells from apical papilla (SCAP) and in vivo capacity to induce pulp-dentin complex formation. MATERIALS AND METHODS: The sealing ability of iRoot BP Plus was measured via scanning electron microscopy (SEM). SCAP were isolated and treated in vitro by iRoot BP Plus conditioned medium, with mineral trioxide aggregate (MTA) conditioned medium and regular medium used as controls, respectively. Cell proliferation was assessed by BrdU labeling and MTT assay and cell migration was evaluated with wound healing and transwell assays. Osteo/odontogenic potential was evaluated by Alizarin red S staining and qPCR. Pulp-dentin complex formation in vivo was assessed by a tooth slice subcutaneous implantation model. RESULTS: iRoot BP Plus was more tightly bonded with the dentin. There was no difference in SCAP proliferation between iRoot BP Plus and control groups (P > 0.05). iRoot BP Plus had a greater capacity to elevated cell migration (P < 0.05) and osteo/odontogenic marker expression and mineralization nodule formation of SCAP compared with MTA groups (P < 0.05). Furthermore, the new continuous dentine layer and pulp-like tissue was observed in the iRoot BP Plus group in vivo. CONCLUSIONS: iRoot BP Plus showed excellent sealing ability, promoted the migration and osteo/odontogenesis of SCAP and induced pulp-dentin complex formation without affecting the cell proliferation, which indicated iRoot BP Plus was a promising coronal sealing material in REPs. CLINICAL RELEVANCE: The coronal sealing materials play crucial roles for the outcomes of REPs. This study showed that iRoot BP Plus has good coronal sealing and promote pulp-dentin complex formation compared with MTA, providing experimental evidences for the clinical application of iRoot BP Plus as a promising coronal seal material in REPs.

Comparison of the removal of intracanal medicaments used in regenerative endodontics from root canal system using needle, ultrasonic, sonic, and laser-activated irrigation systems.

This study aimed to compare the syringe-needle irrigation (SNI), passive ultrasonic irrigation (PUI), EDDY, and shock wave-enhanced emission photoacoustic streaming (SWEEPS) techniques regarding calcium hydroxide and double antibiotic paste removal from the root canal in regenerative endodontic treatments. Eighty single-rooted human teeth were decoronated and enlarged up to #100 to stimulate the immature tooth model. Root canals were irrigated with 1.5% sodium hypochlorite followed by saline solution according to the regenerative endodontic treatment protocol. Dressed teeth were divided into 2 main groups regarding the used intracanal medicaments. Calcium hydroxide and double antibiotic paste were introduced to the canals, and teeth were stored for 3 weeks. Each medicament group was divided into 4 subgroups according to the activation techniques. Medicaments were removed using a 17% EDTA solution. Teeth were split longitudinally into two parts. The remaining medicaments were evaluated under a stereo microscope with a scoring system. Data were analyzed with the Kruskal-Wallis and Mann-Whitney U tests. Regardless of the used irrigation activation systems, there was no statistically significant difference between the removal of the CH and DAP from the root canal (P>0.05). While SWEEPS had the highest ability regarding the removal of intracanal medicaments, syringe-needle irrigation had the lowest (P<0.05). There was no statistically significant difference between PUI and EDDY (P>0.05). Complete removal of intracanal medicaments could not be achieved with any techniques. SWEEPS technology was more effective in removing intracanal medicaments in regenerative endodontic treatments compared to the sonic and ultrasonic irrigation activation systems.

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.

Treatment outcomes of regenerative endodontic therapy in immature permanent teeth with pulpal necrosis: A systematic review and network meta-analysis.

AIM: The aim of this study was to assess which treatment modality regarding scaffold selection for immature permanent teeth with pulpal necrosis will be the most successful for regenerative endodontic treatment (RET). METHODOLOGY: PubMed, Cochrane, Web of Science and Embase, and additional records until August 2022 were searched providing a total of 3021 articles, and nine of these articles were included for quantitative synthesis. The reviewers selected eligible randomized controlled trials and extracted pertinent data. Network meta-analysis was conducted to estimate treatment effects for primary outcomes (clinical and radiographic healing) and secondary outcomes (apical closure, root length and root wall thickness increase) following RET [mean difference (MD); 95% credible interval (CrI) and surface under the cumulative ranking curve (SUCRA)]. The quality of the included studies was appraised by the revised Cochrane risk of bias tool, and the quality of evidence was assessed using the GRADE approach. RESULTS: Six interventions from nine included studies were identified: blood clot scaffold (BC), blood clot scaffold with basic fibroblast growth factor, blood clot scaffold with collagen, platelet pellet, platelet-rich plasma (PRP) and platelet-rich fibrin (PRF). The PRP scaffold showed the greatest increase in root lengthening at 6-12 months (MD = 4.2; 95% CrI, 1.2 to 6.8; SUCRA = 89.0%, very low confidence). PRP or PRF achieved the highest level of success for primary and secondary outcomes at 1-6 and 6-12 months. Blood clot scaffold (with collagen or combined with basic fibroblast growth factor (bFGF)) achieved the highest level of success for secondary outcomes beyond 12 months follow-up. A very low to low quality of evidence suggests that both PRP and PRF exhibit the greatest success evaluating primary and secondary outcomes within 12 months postoperatively compared to the traditional blood clot scaffold protocol. CONCLUSION: Limited evidence suggests both PRP and PRF exhibit success in the short-term, not long-term. The value of this information stems in its recommendation for future randomized trials prioritizing both of these materials in their protocol.