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.

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.

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.

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.

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.

Effect of EDTA Activation on Blood Clot Structure in Regenerative Endodontics: A Scanning Electron Microscopy Study

INTRODUCTION

EDTA plays a crucial role in regenerative endodontic therapy (RET) because of its significant biological effects. However, EDTA is also recognized as the preferred anticoagulant for hematologic tests. Thus, this study aimed to assess the influence of different EDTA activation techniques on the morphology of blood clots after conditioning the root canal dentin.

METHODS

Forty extracted human teeth were prepared to simulate immature teeth and divided into the following 5 groups: (1) saline solution (negative control), (2) EDTA 17% + saline solution (CNI), (3) CNI + ultrasonic activation, (4) CNI + Easy clean activation, and (5) CNI + XP-endo Finisher activation. After irrigation, the roots were cleaved, and the root canals were filled with human blood to clot formation. The morphology and density of erythrocytes, platelets, and the fibrin network were observed using a scanning electron microscope. The fibrin network density was classified using a 4-point scale. Data were analyzed using the Friedman test and the Kruskal-Wallis test with Bonferroni adjustment (α = 5%).

RESULTS

All groups exhibited consistent blood clot morphology characterized by a high density of erythrocytes, platelets, and white blood cells throughout the entire length of the root canal. The negative control group showed statistically significant high scores of fibrin density compared with the CNI group in all root thirds (P < .05). However, there was no statistical difference in the scores for the fibrin network density between the groups irrigated with EDTA with and without activation (P > .05).

CONCLUSIONS

EDTA may impair the fibrin network formation compared with the saline group. However, EDTA activation did not significantly change the effects on the blood clot in contact with the conditioned intraradicular dentin.

Citric Acid Conditioning as an Alternative to EDTA for Growth Factors Release and Stem Cell Response in Regenerative Endodontics: A Systematic Review of In Vitro Studies

INTRODUCTION

Citric acid (CA) conditioning may be a promising alternative to ethylenediaminetetraacetic acid (EDTA) in regenerative endodontic procedures, as reported to improve growth factors' release from dentin. This review systematically investigated the effect of CA conditioning on the growth factors release from dentin and cell behavior compared to EDTA conditioning.

METHODS

Searches were conducted (PubMed/MEDLINE, Scopus, Web of Science, Embase, SciELO, Cochrane Library, and grey literature) until May-2023. Only in vitro studies that evaluated the effects of CA on growth factors' release from dentin and cell behavior outcomes compared to EDTA were included. The studies were critically appraised using a modified Joanna Briggs Institute's checklist. Meta-analysis was unfeasible.

RESULTS

Out of the 335 articles screened, nine were included. Among these, three studies used dentin discs/roots from permanent human teeth; the rest combined them with stem cells. 10% CA for 5 or 10 minute was the most used protocol. Meanwhile, EDTA concentrations ranged from 10% to 17%. In eight studies examining the release of growth factors, five reported a significant release of transforming growth factor-β after dentin conditioning with 10% CA compared to 17% EDTA. Regarding cell behavior (6 studies), three studies assessed cell viability. The findings revealed that 10% CA conditioning showed cell viability similar to those of 17% EDTA. Additionally, in two out of three studies, it was observed that 10% CA conditioning did not affect cell morphology. The studies had a low risk of bias.

CONCLUSIONS

The use of 10% CA to condition dentin for 5-10 minutes resulted in a notable transforming growth factor -β1 release, but its cell responses were similar to those of EDTA.

Current Trends in Regenerative Endodontics: A Web-based Survey

INTRODUCTION

The aim of this study was to ascertain the current trends in regenerative endodontic procedures (REPs) among clinicians, including case selection criteria and clinical protocols.

METHODS

An online questionnaire consisting of provider demographics, case selection criteria for REPs, and clinical protocols was made available to members of the American Association of Endodontists and members of the Endolit website. Data were analyzed using the Fisher exact test.

RESULTS

Two hundred seventy-two responses were analyzed (64.6% were men and 34.7% were women). Of those, 44.5% of respondents practiced in the United States, and 55.5% practiced outside of the Unites States. Most respondents (85.4%) reported performing REPs in their practice, and 92.2% were using sodium hypochlorite as one of their disinfecting irrigants. Calcium hydroxide was the most commonly used intracanal medicament (68.4%), and the majority of respondents use a blood clot alone as the scaffold (73.5%). Most (93%) of the providers reported using a bioceramic material for coronal capping. Practitioners outside the United States were found to be more likely to use adjunctive irrigation activation (P = .003). Younger practitioners preferred REPs over apexification (P = .01). Practitioners outside the United States were more likely to perform an REP in 1 visit (P = .006). Men were found to be more likely to always instrument the canal walls (P = .031). Women were found to be more likely to use manual irrigant activation, whereas men were more likely to use sonic activation (P = .043).

CONCLUSIONS

There is significant heterogeneity within REPs regarding case selection and clinical protocol. Notable differences were observed from the reported findings of REPs from 5 years ago.

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.

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.

Effect of photobiomodulation therapy on TGF-β release from dentin, migration and viability of dental pulp stem cells in regenerative endodontics treatment: An ex vivo study

BACKGROUND AND AIM

Regenerative endodontic procedures (REPs) are oriented by the principles of tissue engineering, incorporating dental pulp stem cells (DPSC), crucial growth factors like Transforming growth factor-β (TGF-β1), and scaffolds to facilitate the regeneration of dental pulp tissues. The present study aimed to investigate the effect of photobiomodulation (PBM) therapy, using an 808 nm diode laser on cellular modulation mechanisms in REPs.

METHOD AND MATERIAL

A total of 108 human dentin discs obtained from intact single root teeth were randomly assigned into six groups (n = 8): 1. Positive control (EDTA), 2. PBM-1 (3 J/cm2), 3. PBM-2 (5 J/cm2), 4. EDTA+PBM-1, 5. EDTA+PBM-2, and 6. Negative control (NaOCl). Then, an extract solution was prepared from each disc and the concentration of released TGF-β1 from the discs was measured using enzyme-linked immunosorbent assay (ELISA). Moreover, the extract solution was added to DPSC culture medium to evaluate cell viability and migration through MTT assay and scratch test, respectively.

RESULT

The group exposed to PBM-1 showed the highest cell viability, while treatment with EDTA and EDTA+PBM-2 decreased cellular viability. Also, the PBM-treated groups showed significantly higher release of TGF-β1 compared to the negative control. EDTA and EDTA+PBM-1 showed the highest release among all the groups. No significant difference was found between EDTA and EDTA+PBM-1, as well as between PBM-1 and PBM-2. Moreover, the PBM-1 group exhibited the highest migration after 24 h, which was significantly greater than other groups, except for the PBM-2 group.

CONCLUSION

According to the obtained data, 808 nm mediated-PBM (3 J/cm2), both independently and in conjunction with EDTA, enhanced the release of TGF-β1 from dentin and improved cell viability and migration of DPSCs. It seems that, PBM under the specific parameters employed in this study, could be an effective adjunctive therapy in REPs.

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.

Clinical, Radiographic, and Histologic Outcomes of Regenerative Endodontic Treatment in Human Immature Teeth Using Different Biological Scaffolds: A Systematic Review and Meta-analysis

BACKGROUND

Biological scaffolds such as blood clot (BC), platelet-rich plasma (PRP), platelet- rich fibrin (PRF), and platelet pellet (PP) are used in regenerative endodontic treatments (RETs).

OBJECTIVE

To systematically and quantitatively evaluate clinical, radiographic, and histologic outcomes of RET studies using different biological scaffolds.

METHODS

MEDLINE, Scopus, Cochrane library, and Embase were searched to identify studies on RET procedures with any scaffold type performed on immature non-vital human teeth, employing any type of biological scaffold. Clinical, radiographic, and histologic outcomes were extracted. Cochrane collaboration risk of bias tool and Newcastle-Ottawa scale were used for quality assessment. Random and fixed model meta-analysis was carried out with 95% confidence interval.

RESULTS

Thirty-two studies were included in the qualitative analysis from the primarily retrieved 1895 studies. Only one study had high risk of bias and 71.8% of the studies had high quality. None of the studies reported any histologic findings. Thirty studies were included in meta-analysis. Clinical success rate of RET using either BC, PRP, or PRF was >99%. Furthermore, 32%, 23%, and 27% of BC, PRP, and PRF cases regained vitality, respectively. Periapical healing was seen in 67%, 75%, and 100% of BC, PRP, and PRF cases, respectively. There was no statistical difference between BC, PRP, or PRF regarding clinical success or any radiographic outcomes.

CONCLUSION

There was no significant difference between BC, PRP, and PRF in terms of clinical and radiographic outcomes. When it is difficult or dangerous to induce bleeding in root canals, PRP and PRF may be employed instead.

Effects of Growth Factors on the Differentiation of Dental Stem Cells: A Systematic Review and Meta-analysis (Part I)

INTRODUCTION

To evaluate the biological interaction between dental stem cells (DSCs) and different growth factors in the field of regenerative endodontics.

METHODS

A systematic search was conducted in the electronic databases up to October 2021. This study followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Ex vivo studies evaluating the biological interactions of DSCs and growth factors were included. The meta-analysis was performed according to the type of growth factor. The outcomes were cell viability/ proliferation and mineralization. Standardized mean differences (SMDs) were estimated using the random-effect maximum-likelihood method (P < .05). Additional analysis was performed to find any potential source of heterogeneity.

RESULTS

Twenty articles were included in the systematic review; meta-analysis was performed for fibroblast growth factor-2 (FGF-2) and Transforming growth factor-ß1 (TGF-β1) (n = 5). Results showed that use of FGF-2 significantly increased cell proliferation on day 1-(SMD = 3.56, P = 0.00), 3-(SMD = 9.04, P = 0.00), 5-(SMD = 8.37, P = 0.01), and 7 (SMD=8.51, P=0.00) than the control group. TGF-ß1 increased alkaline phosphatase (ALP) activity more than control only on day 3 (SMD = 3.68, P = 0.02). TGF-β1 had no significant effect on cell proliferation on days 1 and 3 (P > 0.05) and on ALP activity on days 5 and 7 (P > 0.05). Meta-regression analysis showed that different covariates (i.e., cell type, passage number, and growth factors' concentration) could significantly influence the effect sizes at different follow- ups (P < 0.05).

CONCLUSION

Specific growth factors might enhance the proliferation and mineralization of DSCs; however, the obtained evidence was weak. Due to the high heterogeneity among the included studies, other growth factors' inhibitory/stimulatory effects on DSCs could not be evaluated.

Treatment outcomes of regenerative endodontic procedures in nonvital mature permanent teeth: a retrospective study

OBJECTIVES

This retrospective study was undertaken to clinically and radiographically evaluate the long-term outcomes of regenerative endodontic procedures (REPs) for nonvital mature permanent teeth, to analyze predictors influencing treatment outcomes.

METHODS

Nonvital mature permanent teeth treated by REPs with a minimum follow-up period of 6 months were included from 2015 to 2017. Treatment outcomes were categorized as success and failure. The periapical status and lesion healing were assessed in terms of the periapical index (PAI) and the percentage changes in periapical radiolucency (PARL) area. The clinical and radiographic outcomes of REPs were assessed by Mann-Whitney test at different follow-up period. Kaplan-Meier curves and Univariate Cox regression analysis were conducted to assess the success and identify potential predictors affecting outcomes, respectively.

RESULTS

A total of 37 mature teeth with an average follow-up of 4.3 years satisfied the criteria, and 89.2% of the teeth had a successful outcome. Significant differences in PAI scores were found between each period with respect to the baseline (p < .05). Among different periods, there was a significant difference between intervals of 3-6 months and 7-12 months (p = .039) and no significant difference between each interval of more than 12 months (p > .05). Eighty-seven percent of teeth with preoperative PARL presented completely healed. REPs significantly decreased the PARL area at the interval of 7-12 months compared to 3-6 months (p = .025), with no significant difference between each interval of more than 12 months (p > .05). No significant predictor was found for the success of outcome (p > .05). Thirteen teeth (35.1%) regained pulp sensibility, and 40.5% of the teeth exhibited intracanal calcification.

CONCLUSIONS

Within the limitations of this study, REPs provided a high long-term success rate and promoted the resolution of PARL as a biologically-based alternative treatment option for nonvital mature teeth.

CLINICAL RELEVANCE

REPs provide a high long-term success rate and promoted healing of apical periodontitis comparable with reported outcomes for root canal therapy of mature teeth.

3D finite element analysis of stress distribution as a result of oblique and horizontal forces after regenerative endodontic treatment part II: comparison of material thickness

AIM

This study aimed to evaluate the stress distribution caused by secondary trauma forces after regenerative endodontic treatment (RET) using different thicknesses of coronary barrier material with three-dimensional finite element analysis(FEA).

METHOD

A control model was created using the tomography image of the immature maxillary central tooth with computer software.Study models were created with the modulus of elasticity and Poisson's ratio of the materials used in RET.Enamel, dentin, cementum, periodontal ligament, cortical, and cancellous bone were modeled. Coronary barrier materials were applied in 3 mm and 5 mm thicknesses (Model 1: control model, model 2:3 mm/Calcium Enriched Mixture(CEM), model 3:3 mm/Mineral Trioxide Aggregate(MTA), model 4:3 mm/Biodentin, model 5:5 mm/CEM, model 6:5 mm/MTA, model 7:5 mm/Biodentin). For the trauma force simulation, 300 N force in the horizontal direction was applied to the buccal surface of the tooth in the first scenario. For the second scenario, maximum bite force simulation, a force of 240 N in the oblique direction was applied to the palatal surface of the tooth. FEA was performed with Algor Fempro. The resulting stresses were recorded as Von Mises, maximum, and minimum principal stresses.

RESULTS

Lower stress values were obtained in 5 mm models compared to 3 mm models. However, the difference between them was insignificant. Lower stress values were obtained in all RET models compared to the control model. The lowest stress values in dental tissues and bone tissue were obtained in the CEM models.

CONCLUSION

This is the first study in which the stress caused by different thicknesses of CEM on dental tissues was evaluated with FEA. RET strengthens immature teeth biomechanically. CEM and Biodentin are more successful materials in stress distribution than MTA. Considering the cost of treatment, 3 mm material thickness is ideal for RET since there is no significant difference between the stress values resulting from the use of 5 mm and 3 mm coronary barrier material.

Pulp regeneration: follow the guide

Introduction

What if we changed our point of view? What if we approached endodontics from a biological perspective rather than a mechanistic one? What if, in the case of pulpal tissue necrosis, we were to consider an alternative to apexification therapies? Is pulp tissue regeneration now possible?

Objective

Regenerative endodontic therapy (RET) aims to regenerate the pulp-dentin complex damaged by infection, trauma, or developmental anomaly of immature permanent teeth with necrotic pulp. The new intracanal tissue formation is expected to display pulp-like architecture and functions. There are two different based to tissue engineering approaches described to perform RET: cell-free CF-RET that attempt to induce host endogenous cells or stem cells to migrate into the root canal for regeneration or cell-based CB-RET which introduce exogenously prepared cells or stem cells into the canal for regeneration.

Material and Method

CB-RET is the basis of current protocols recommended by the American Association of Endodontists (AAE) and the European Society of Endodontology (ESE) for the treatment of necrotic immature permanent teeth, with or without LIPOE. In this article, after defining the above-mentioned concepts, we will describe the ESE protocol and discuss the key steps for "getting started with endodontic regeneration".

Conclusion

Each stage of the protocol must be carried out rigorously so as not to compromise the stages of the various biological processes involved. The practitioner has to stay informed of advances in knowledge resulting from research and new protocols to be published.

Treatment outcomes of immature permanent necrotic evaginated teeth: A retrospective study comparing regenerative endodontic procedures with apexification

BACKGROUND

Few studies have compared the outcomes of regenerative endodontic procedures (REPs) and calcium hydroxide apexification focusing on necrotic teeth with dens evaginatus.

AIM

To qualitatively and quantitatively compare the treatment outcomes of REPs and calcium hydroxide apexification in teeth with dens evaginatus.

DESIGN

Immature permanent necrotic evaginated teeth treated with REPs or calcium hydroxide apexification for a follow-up period of at least 12 months were included. Tooth success and survival rates were analyzed. Changes in radiographic root length, apical diameter, and radiographic root area (RRA) were quantified. Prognostic factors that might influence RRA were identified via multivariate linear regression analysis.

RESULTS

A total of 112 teeth (50 REP cases and 62 apexification cases) with a median follow-up period of 26.5 months were included. Regenerative endodontic procedures and calcium hydroxide apexification exhibited similar satisfactory success and survival rates (p > .05). Additionally, 88 teeth were quantitatively analyzed. The REP group presented a significantly greater percentage increase in RRA and less decrease in apical diameter than the calcium hydroxide apexification group (p < .05). Teeth treated with REPs and with Stages 7 and 8 of root development showed a better gain in RRA (p < .05).

CONCLUSION

While REP and calcium hydroxide apexification had similar success and survival rates, teeth with REPs showed an increase in RRA, indicating that REP is the preferred choice.

Short fiber reinforced composite on fracture strength of immature permanent anterior teeth with simulated regenerative endodontic procedures: an in vitro study

The aim of the present study was to evaluate the effect of short fiber reinforced composite on the fracture strength of anterior immature teeth treated with regenerative endodontic procedures. A total of 120 permanent maxillary central incisors were selected, and root lengths were standardized. Except for the positive control group (n = 20), the root canals were instrumented to simulate immature teeth with incomplete root development, and the regenerative endodontic procedure was performed. Twenty instrumented teeth acted as negative controls (n = 20), and the remaining 80 teeth were randomly divided into 4 groups according to the chosen coronal restoration material: bulk fill, short fiber reinforced composite (SFRC), polyethylene fiber (Ribbond Ultra), and flowable composite resin. Each specimen was then subjected to fracture testing using a universal testing machine (AGS-X, Shimadzu, Japan). The load to fracture was recorded. Data were subjected to statistical analysis using analysis of variance and the Tukey Honestly Significant Difference test. A significant difference was detected between the groups (p < 0.05), with the positive control group showing the highest mean fracture strength. The SFRC group had significantly higher values than the bulk fill, polyethylene fiber, flowable composite resin and negative control groups. In conclusion, SFRC has a relatively high fracture strength compared to other materials used in regenerative endodontic procedures. The use of SFRC enhanced the fracture strength of immature permanent teeth.

Expression of Toll-like Receptors in Stem Cells of the Apical Papilla and Its Implication for Regenerative Endodontics

Regenerative therapies to replace cells and tissues damaged due to trauma and dental infections require temporal and spatial controlled recruitment and the differentiation of progenitor/stem cells. However, increasing evidence shows microbial antigens can interfere with this process. Toll-like receptors (TLRs) are crucial in recognizing pathogen-associated molecular patterns. Stem cells of the apical papilla (SCAP) are required for normal dental development and are intimately involved in the reparative and regenerative capacity of developing teeth. We hypothesized that TLRs are expressed in SCAP and that the activation of TLR2/TLR4 or TLR3 by different ligands results in differential cellular fate, impacting their differentiation into a mineralizing phenotype. We found that most TLRs are expressed as detected by PCR except TLR7 and TLR8; exposure to heat-killed E. coli results in upregulating TLR2 and TLR4 and reducing mineralization capacity. In addition, bacterial exposure resulted in the upregulation of 11 genes, of which 9 were chemokines whose proteins were also upregulated and released, promoting in vitro macrophage migration. On the other hand, TLR3 activation resulted in increased proliferation and a dramatic inhibition of osteogenic and odontoblastic differentiation, which was reversed by inhibition or the knockdown of TLR3 expression. The profound effects of TLR activation resulting in different cell fates that are ligand and receptor-specific warrants further evaluation and represents an important therapeutic target to make regenerative approaches more predictable following dental infections.

Role of Dental Pulp Stem Cells to Promote Angiogenesis in Cell-based Regenerative Endodontics

Maintaining the viability and avoiding necrosis of dental pulp are crucial to preserving the structural integrity and functioning of teeth. In recent years, cell-based regenerative endodontics has emerged as a promising approach to achieve this goal and has gained increasing attention in scientific research; however, in the confined space of the root canal system, hypoxic conditions can be both beneficial and detrimental, as they may promote angiogenesis in the graft to some extent but also lead to tissue necrosis if prolonged. Dental pulp stem cells (DPSCs) have been verified as multipotent cells that can promote angiogenesis and are therefore ideal candidates for realising real dental pulp regeneration within root canals. Thus, we focus on the underlying mechanisms of DPSCs to promote angiogenesis and summarise some preclinical studies and clinical trials involving transplanting of DPSCs to achieve real dental pulp regeneration, in the hope that this intractable source of perplexity in regenerative endodontics may be resolved sooner.

Regenerative endodontic treatment of an immature incisor tooth with a novel platelet-rich product: A five-year follow-up case report

This case report presents a five-year follow-up and the management of a necrotic, immature incisor tooth treated by a novel platelet-rich plasma/platelet extract solution and platelet-rich fibrin (PRP-PES/PRF) and the restoration by using a stress-reduced direct composite restoration (SRDC) technique. The patient with a broken maxillary lateral tooth was referred to our clinic. Extra/intra-oral examinations were within normal limits. The nonvital tooth having an apical lesion and open-apical apex was treated with a regenerative endodontic treatment procedure (REP), and further root development with continued apical closure was shown in the follow-ups up to 60 months. In conclusion, the SRDC and PRP-PES/PRF combination can be an opportunity for the teeth requiring post-restoration. In contrast to the treatment strategy susceptible to weakening or fracturing the patient's tooth root, the REP approach may lead to a better prognosis for the patient's tooth.

Attitude and practice of regenerative endodontic procedures among endodontists and paediatric dentists: A multinational survey from 13 countries

BACKGROUND

Regenerative endodontics (RET) refers to biologically based procedures that aim to restore damaged tooth structures and reinstate the pulp-dentine complex to its normal physiological state.

AIM

The purpose of this study was to examine the attitudes and practices of endodontists and paediatric dentists regarding RET.

DESIGN

A survey was conducted among endodontists and paediatric dentists from 13 countries. A number of factors were evaluated, including frequency of RET application, followed guidelines, disinfection techniques, intracanal medication type, scaffold type, preferred coronal seal material, and follow-up period.

RESULTS

Among the 1394 respondents, 853 (61.2%) and 541 (38.8%) were endodontists and paediatric dentists, respectively. Almost half (43%) of participants have not performed RET yet. The American Association of Endodontics guideline (47.3%) was selected as the primary source for the clinical protocol. The most frequently selected irrigant solution was 1.5%-3% NaOCl at the first (26.1%) and second (13.6%) sessions. A blood clot (68.7%) and MTA (61.9%) were the most frequently selected scaffold type and coronal barrier. Most participants preferred a 6-month follow-up period.

CONCLUSION

According to this survey, deviations exist from current RET guidelines regarding all aspects evaluated. Standardizing clinical protocols and adhering to available guidelines would help to ensure more predictable outcomes.

Regenerative endodontic procedures: are they more successful in mature permanent teeth with necrotic pulp than in immature teeth?

DATA SOURCES

Five scientific databases were electronically searched: PubMed, EMBASE, OpenGrey, Web of Science and Cochrane Library.  The search was conducted until 17 February 2022 without any restriction on date of publication but was restricted to English language. Relevant studies were also screened for related publications. The aim of this systematic review and meta-analysis was to evaluate the effectiveness of regenerative endodontic procedures (REPs) in mature and immature permanent teeth with necrotic pulp and to evaluate if the success rate was affected by the stage of root development.

STUDY SELECTION

Types of studies: all of the included studies were randomised controlled trials (RCTs).

TYPES OF PARTICIPANTS

people with necrotic permanent teeth (immature or mature) treated with regenerative endodontic procedures. Types of interventions: regenerative endodontic procedures. Language: RCTs published in English.

EXCLUSION CRITERIA

Types of studies: (1) case reports, (2) retrospective cohort trials, (3) prospective cohort trials, (4) animal trials, (5) in-vitro trials, (6) non-randomised trials.

POPULATION

primary teeth. Types of interventions: no details about the clinical procedures. Follow-up period: <6 months.

DATA EXTRACTION AND SYNTHESIS

The titles and abstracts of the RCTs identified by the search strategies were independently screened by two reviewers. After the initial screening, the full text of the relevant trials were reassessed against the inclusion and exclusion criteria. Discrepancies and disagreements were resolved by consensus after including a third reviewer.

RESULTS

Following the initial electronic and manual searches, a total of 3766 articles were initially identified. This was reduced to 2739 articles after duplicates were removed. However, after the initial screening phase, 35 articles were considered potentially relevant and qualified for full-text scrutiny. Out of the 35 articles, only 27 were considered eligible for inclusion. The differences in the success rate and the asymptomatic rate between the mature and immature permanent teeth with necrotic pulp were not statistically significant. However, the differences between the two groups were statistically significant in the rate of positive response to electrical pulp testing.

CONCLUSIONS

Based on the results of this systematic review and meta-analysis, the authors concluded that REPs are an effective therapy and can achieve high success rates for both mature and immature necrotic permanent teeth. It was also concluded that the REPs were more successful in regaining vitality responses for mature compared with immature permanent teeth with necrotic pulps.

Efficacy of disinfection procedures performed prior to regenerative endodontic therapy: An integrative review

The aim of this integrative review was to identify whether the disinfection procedures performed prior to regenerative endodontic treatment were effective on biofilm removal from the root canals. The research was based on PubMed, Latin American and Caribbean Health Sciences Literature (Lilacs) and Scientific Electronic Library Online (SciELO) databases. Four articles were selected; one of the studies was in vivo and the others ex vivo. Different disinfection procedures were studied, characterised mainly by the use of intracanal medication, highlighting the double antibiotic paste, triple antibiotic paste and calcium hydroxide paste. Disinfection ability was evaluated against Enterococcus faecalis and multispecies biofilms by using the fluorescence technique and colony forming unit counting, for 7 to 21 days. Double antibiotic paste and triple antibiotic paste demonstrated excellent antibiofilm activity, unlike CH paste that showed limited disinfection, even when associated with different antimicrobial agents. Triple antibiotic paste was the most effective medication against biofilm.

Evaluation of the effectiveness of different treatment approaches in preventing coronal discoloration caused by regenerative endodontic treatment

OBJECTIVES

This study aimed to evaluate the effectiveness of Teethmate desensitizer, a dentin bonding agent (DBA), Nd:YAG laser, and Er:YAG laser, which provides dentin tubule occlusion in the pulp chamber with different mechanisms, in preventing tooth discoloration due to regenerative endodontic treatment.

MATERIALS AND METHODS

One hundred five extracted maxillary human incisors with single roots and single canals were included in the study. The apical third of each tooth was resected below the enamel-cementum junction (CEJ) to obtain a standard root length as 10 ± 1 mm. Root canal preparation was performed using the ProTaper Next files up to X5. Root canals were prepared with Gates Glidden (# 2-4) burs to simulate the immature root apex and an apical diameter of 1.1 ± 0.1 mm was obtained. The teeth were randomly divided into 7 groups (n = 15): DBA, Teethmate, Nd:YAG, Er:YAG, Biodentine, Blood, and Negative Control. Relevant dentin tubule occlusion methods were applied to DBA, Teethmate, Nd:YAG, and Er:YAG groups. Following dentin tubule occlusion procedures, Biodentine was placed on the blood clot after filling the root canals with blood up to 4 mm below the CEJ. No dentin tubule occlusion procedure was applied for Blood and Biodentine groups. Color measurement was performed with the spectrophotometer Vita Easyshade Advance before treatment, immediately after treatment, and at days 7, 30, and 90. Data were converted to L*a*b color values of Commission International de I'Eclairage (CIE L*a*b) and ΔE values were calculated. Two-way ANOVA and post hoc Tukey test (p = 0.05) were performed for statistical analysis.

RESULTS

A clinically detectable color change was observed in all groups except for the negative control (ΔE ≥ 3,3). It was observed that Biodentine used alone has a potential for discoloration. It was determined that as the contact time with blood increased, tooth discoloration increased. However, no significant difference was found between dentin tubule occlusion methods in preventing color change (p > 0.05).

CONCLUSIONS

It was determined that no dentin tubule occlusion method could 100% prevent discoloration caused by RET.

CLINICAL RELEVANCE

DBA and Teethmate, which do not have a significant difference in terms of preventing color change, are considered to be suitable for dentin tubule occlusion due to their ease of application and low cost compared to Nd:YAG laser and Er:YAG laser.

Regenerative endodontic treatment using autologous blood from alveolar bone for mature permanent premolar with apical periodontitis: a case report

OBJECTIVE

The formation of blood clot, achieved through periapical bleeding or the use of peripheral venous blood, platelet-rich plasma (PRP) or platelet-rich fibrin (PRF), has been widely utilized in regenerative endodontic procedures (REPs). Except for inducing periapical bleeding, the scaffolds obtained from PRP, PRF, and venous blood are not derived from oral and maxillofacial tissues. In this case report, autologous blood clots from alveolar bone were described, which involved puncturing the maxillary terminal alveolar bone. The purpose of this case report was to assess the efficacy of the alveolar-derived blood clot in regenerative endodontic procedures in a mature permanent premolar.

METHODS

A mature premolar had a fractured central cusp, one of the developmental aberrations of tooth, without a proper treatment, resulting in chronic periapical lesion. To address this condition, REPs were employed, utilizing blood obtained through aspiration from the maxillary terminal alveolar bone aspiration.

RESULT

Follow-up examinations of tooth #29 revealed the absence of clinical symptoms, a progressive resolution of a periapical lesion area and thickening of the root canal walls.

CONCLUSION

This case demonstrated that blood clot obtained through paracentesis of the maxillary terminal alveolar bone could be successfully applied in REPs and has potential to manage periapical lesions. However, further and more clinical trials are required to verify the feasibility of the alveolar-derived blood clot in REPs and compare the outcome of alveolar-derived blood clot with currently used biological scaffolds.

CLINICAL RELEVANCE

In comparison to PRP or PRF from peripheral venous blood, blood clots obtained via paracentesis of the maxillary terminal alveolar bone could be administrated by dentists, eliminating the need for reliance on professional nurses. The use of blood clots from alveolar bone could simplify the REPs in cases where periapical blood was insufficient to brim the root canals.

Evaluation of concentrated growth factor and blood clot as scaffolds in regenerative endodontic procedures: A retrospective study

The study aims to investigate and compare the success rate of concentrated growth factor (CGF) and blood clot (BC) as scaffolds in regenerative endodontic procedures (REPs). Immature permanent necrotic teeth treated by REPs with at least a 6-month follow-up were included. These teeth were divided into the CGF (53 teeth) and BC (68 teeth) groups. Treatment outcomes were assessed using a combined clinical and radiographic scoring system. The total success rate was 91.74% over a mean follow-up period of 23.15 months. There was no significant difference between the CGF group (86.79%) and BC group (95.59%). The success rate of traumatic teeth (84.31%) was significantly lower than that of teeth with developmental dental anomalies (98.39%) (p < 0.05). CGF may be a suitable alternative scaffold in REPs when adequate bleeding cannot be achieved. Moreover, compared to developmental dental anomalies, traumatic teeth treated by REPs may be more vulnerable to failure.

The efficacy of concentrated growth factor and platelet-rich fibrin as scaffolds in regenerative endodontic treatment applied to immature permanent teeth: a retrospective study

BACKGROUND

The aim of this retrospective study was to compare the efficacy of concentrated growth factor (CGF) and platelet-rich fibrin (PRF) as scaffolds in regenerative endodontic therapy (RET).

METHODS

Necrotic immature permanent teeth treated with regenerative endodontic therapy during January 2018 to August 2022 were divided into the CGF and PRF groups according to the scaffold. The CGF and PRF groups included 7 and 6 teeth, respectively. The efficacy of regenerative endodontic therapy was analyzed based on the clinical and radiological outcomes at three different follow up periods: T1 (3-6 months), T2 (6-12 months) and T3 (12-24 months). Statistical analysis was performed using the independent T test, Mann-Whitney test and Fisher's exact test at a significance level of 0.05.

RESULTS

The success rate of each stage in both groups was 100%. Through quantitative comparison of radiographic outcomes, there was no statistically significant difference between the two groups in terms of root development and periapical lesion healing at each stage, except that the increase rate of radiographic root area in PRF group in the T3 stage was above one in CGF group with statistically significance.

CONCLUSIONS

Both CGF and PRF had a similar clinical performance regarding resolution of clinical signs and symptoms, periapical lesion healing, and continued root development as scaffolds in RET. Further prospective studies with large samples for longer follow-up periods are needed.

Treatment Outcome of Regenerative Endodontic Procedures for Necrotic Immature and Mature Permanent Teeth: A Systematic Review and Meta-Analysis Based on Randomised Controlled Trials

PURPOSE

To analyse whether the stage of apical development affects the effectiveness of regenerative endodontic treatment by comparing the outcomes for necrotic mature and immature permanent teeth treated with regenerative endodontic procedures.

MATERIALS AND METHODS

Multiple databases (PubMed, Cochrane Library, Web of Science, EMBASE and OpenGrey databases) were searched through February 17th, 2022. Inclusion criteria were randomised controlled trials that included treatment of necrotic immature or mature permanent teeth using any regenerative endodontic procedures (REPs) that aimed to achieve pulp revascularisation or regeneration. The Cochrane Risk of Bias 2.0 tool was used to assess risk of bias. The included indicators were asymptomatic sign, success, pulp sensitivity, and discolouration. The extracted data were expressed by percentage for statistical analysis. The random effect model was used to explain the results. Comprehensive Meta-Analysis Version 2 was used to perform the statistical analyses.

RESULTS

Twenty-seven RCTs were eligible for inclusion in the meta-analysis. The success rates of necrotic immature and mature permanent teeth were 95.6% (95% CI, 92.4%-97.5%; I2=34.9%) and 95.5% (95%CI, 87.9%-98.4%; I2=0%), respectively. The asymptomatic rates of necrotic immature and mature permanent teeth were 96.2% (95%CI, 93.5%-97.9%; I2=30.1%) and 97.0% (95%CI, 92.6%-98.8%; I2=0%), respectively. The treatment of immature and mature necrotic permanent teeth with REPs yields high success rates and low symptomatic rates. The incidence of positive sensitivity response for electric pulp testing in necrotic immature permanent teeth (25.2% [95% CI, 18.2%-33.8%; I2=0%]) was lower than that in necrotic mature permanent teeth (45.4% [95% CI, 27.2%-64.8%; I2=75.2%]), and this difference was statistically significant. The restoration of pulp sensitivity seems to be more evident in necrotic mature permanent teeth than in necrotic immature permanent teeth. The crown discolouration rate of immature permanent teeth was 62.5% (95% CI, 49.7%-73.8%; I2=76.1%). Necrotic immature permanent teeth have a considerable crown discolouration rate.

CONCLUSION

REPs for both immature and mature necrotic permanent teeth yield high success rates and promote root development. The vitality responses seem to be more evident in necrotic mature permanent teeth than in necrotic immature permanent teeth.

Gelatin methacryloyl hydrogel as an injectable scaffold with multi-therapeutic effects to promote antimicrobial disinfection and angiogenesis for regenerative endodontics

Regenerative endodontics represents a paradigm shift in dental pulp therapy for necrotic young permanent teeth. However, there are still challenges associated with attaining maximum root canal disinfection while supporting angiogenesis and preserving resident stem cells viability and differentiation capacity. Here, we developed a hydrogel system by incorporating antibiotic-eluting fiber-based microparticles in gelatin methacryloyl (GelMA) hydrogel to gather antimicrobial and angiogenic properties while prompting minimum cell toxicity. Minocycline (MINO) or clindamycin (CLIN) was introduced into a polymer solution and electrospun into fibers, which were further cryomilled to attain MINO- or CLIN-eluting fibrous microparticles. To obtain hydrogels with multi-therapeutic effects, MINO- or CLIN-eluting microparticles were suspended in GelMA at distinct concentrations. The engineered hydrogels demonstrated antibiotic-dependent swelling and degradability while inhibiting bacterial growth with minimum toxicity in dental-derived stem cells. Notably, compared to MINO, CLIN hydrogels enhanced the formation of capillary-like networks of endothelial cells in vitro and the presence of widespread vascularization with functioning blood vessels in vivo. Our data shed new light onto the clinical potential of antibiotic-eluting gelatin methacryloyl hydrogel as an injectable scaffold with multi-therapeutic effects to promote antimicrobial disinfection and angiogenesis for regenerative endodontics.

Regenerative Endodontic Procedures in Teeth with Root Resorption: A Systematic Review

The purpose of this systematic review was to critically evaluate the available clinical literature on the use of regenerative endodontic therapy (RET) for the treatment of root resorption. All case reports, case series and clinical studies documenting the management of root resorption in mature or immature permanent teeth using RET were included. Review articles, animal studies, and RET in teeth showing developmental anomalies were excluded. A literature search was conducted in electronic databases MEDLINE, Scopus, Cochrane, and Google Scholar from 2001 to January 2022. The JBI Critical Appraisal Checklist Quality was used to appraise the included case reports and case series. The Methodological item for non-randomised studies (MINORS) tool was used to appraise the clinical study critically. After applying the inclusion and exclusion criteria, the search resulted in 14 studies (12 case reports, 1 case series, and 1 clinical study) accounting for root resorption in 34 teeth from 29 patients treated with RET. Despite the wide variation in RET protocols, the arrest of root resorption and resolution of symptoms was seen in all teeth except one (failure after 27 months). The clinical study's cone beam computed tomography (CBCT) imaging evalu- ation documented a significant volumetric decrease in resorptive and periapical lesions after RET. The clinical study was deemed as good quality using the MINORS scale. The JBI critical appraisal tool showed that the case series was of poor quality; 11 of the case reports were of good quality, while 1 case report was of fair quality. This systematic review revealed a low-to-moderate level of evidence for the use of RET in resorption cases. However, further well-designed, long-term clinical studies are required to recommend it as an alternative treatment option for root resorption management. Funding: None. The systematic review was registered in PROSPERO (CRD42021274569). (EEJ-2022-11-136).

Tissue Characteristics in Endodontic Regeneration: A Systematic Review

The regenerative endodontic procedure (REP) represents a treatment option for immature necrotic teeth with a periapical lesion. Currently, this therapy has a wide field of pre-clinical and clinical applications, but no standardization exists regarding successful criteria. Thus, by analysis of animal and human studies, the aim of this systematic review was to highlight the main characteristics of the tissue generated by REP. A customized search of PubMed, EMBASE, Scopus, and Web of Science databases from January 2000 to January 2022 was conducted. Seventy-five human and forty-nine animal studies were selected. In humans, the evaluation criteria were clinical 2D and 3D radiographic examinations. Most of the studies identified a successful REP with an asymptomatic tooth, apical lesion healing, and increased root thickness and length. In animals, histological and radiological criteria were considered. Newly formed tissues in the canals were fibrous, cementum, or bone-like tissues along the dentine walls depending on the area of the root. REP assured tooth development and viability. However, further studies are needed to identify procedures to successfully reproduce the physiological structure and function of the dentin–pulp complex.

Photocrosslinkable methacrylated gelatin hydrogel as a cell-friendly injectable delivery system for chlorhexidine in regenerative endodontics

OBJECTIVES

This work sought to formulate photocrosslinkable chlorhexidine (CHX)-laden methacrylated gelatin (CHX/GelMA) hydrogels with broad spectrum of action against endodontic pathogens as a clinically viable cell-friendly disinfection therapy prior to regenerative endodontics procedures.

METHODS

CHX/GelMA hydrogel formulations were successfully synthesized using CHX concentrations between 0.12 % and 5 % w/v. Hydrogel microstructure was evaluated by scanning electron microscopy (SEM). Swelling and enzymatic degradation were assessed to determine microenvironmental effects. Compression test was performed to investigate the influence of CHX incorporation on the hydrogels' biomechanics. The antimicrobial and anti-biofilm potential of the formulated hydrogels were assessed using agar diffusion assays and a microcosms biofilm model, respectively. The cytocompatibility was evaluated by exposing stem cells from human exfoliated deciduous teeth (SHEDs) to hydrogel extracts (i.e., leachable byproducts obtained from overtime hydrogel incubation in phosphate buffer saline). The data were analyzed using One- and Two-way ANOVA and Tukey's test (α = 0.05).

RESULTS

CHX/GelMA hydrogels were effectively prepared. NMR spectroscopy confirmed the incorporation of CHX into GelMA. The addition of CHX did not change the micromorphology (pore size) nor the swelling profile (p > 0.05). CHX incorporation reduced the degradation rate of the hydrogels (p < 0.001); whereas, it contributed to increased compressive modulus (p < 0.05). Regarding the antimicrobial properties, the incorporation of CHX showed a statistically significant decrease in the number of bacteria colonies at 0.12 % and 0.5 % concentration (p < 0.001) and completely inhibited the growth of biofilm at concentration levels 1 %, 2 %, and 5 %. Meanwhile, the addition of CHX, regardless of the concentration, did not lead to cell toxicity, as cell viability values were above 70 %.

SIGNIFICANCE

The addition of CHX into GelMA showed significant antimicrobial action against the pathogens tested, even at low concentrations, with the potential to be used as a cell-friendly injectable drug delivery system for root canal disinfection prior to regenerative endodontics.

Regenerative Endodontic Procedures: Management of Immature Necrotic Permanent Teeth

Immature permanent teeth are prone to pulpal necrosis due to dental caries, traumatic injury, or developmental malformation. These cases can lead to arrested root development, accompanied by thin root dentinal walls and open apices. Therefore, the efficient disinfection and adequate filling of root canals can often be challenging for clinicians.

[Biological basis and clinical exploration of regenerative endodontic therapy]

Regenerative endodontic therapy is a tissue engineering based approach of treatment for endodontic disease. Its purpose is to achieve the regeneration of the pulp-dentin complex, thus to promote root development of the immature permanent tooth with necrotic pulp. Like other treatments based on tissue engineering techniques, the success of regenerative pulp therapy depends on such three elements as seed cells, scaffold materials and growth factors. Since its inception 20 years ago, there have been various terminologies in the literature, with similarities and differences in connotation. The present article summarizes and analyzes the term evolution, biological basis, clinical considerations and future scientific research directions of regenerative endodontics, in order to find out the unsolved scientific problems and to promote the development and standardization of this technique in clinical practice.

Regenerative Endodontic Procedure of Immature Permanent Teeth with Leukocyte and Platelet-rich Fibrin: A Multicenter Controlled Clinical Trial

INTRODUCTION

The aim of this nonrandomized, multicenter controlled clinical trial was to evaluate the impact of leukocyte-platelet-rich fibrin (LPRF) on regenerative endodontic procedures (REPs) of immature permanent teeth in terms of periapical bone healing (PBH) and further root development (RD).

METHODS

Healthy patients between 6-25 years with an inflamed or necrotic immature permanent tooth were included and divided between the test (= REP + LPRF) and control (= REP-LPRF) group depending on their compliance and the clinical setting (university hospital or private practice). After receiving REP ± LPRF, the patients were recalled after 3, 6, 12, 24, and 36 months. At each recall session, the teeth were clinically and radiographically (by means of a periapical radiograph [PR]) evaluated. A cone-beam computed tomographic (CBCT) imaging was taken preoperatively and 2 and 3 years postoperatively. PBH and RD were quantitatively and qualitatively assessed.

RESULTS

Twenty-nine teeth with a necrotic pulp were included, from which 23 (9 test and 14 control) were analyzed. Three teeth in the test group had a flare-up reaction in the first year after REP. Except for 2 no shows, all the analyzed teeth survived up to 3 years after REP, and, in case of failure, apexification preserved them. Complete PBH was obtained in 91.3% and 87% of the cases based on PR qualitative and quantitative evaluation, respectively, with no significant difference between the groups with respect to the baseline. The PR quantitative change in RD at the last recall session with respect to the baseline was not significant (all P values > .05) in both groups. The qualitative assessment of the type of REP root healing was nonuniform. In the test group, 55.6% of the teeth presented no RD and no apical closure. Only 50% of the 14 teeth assessed with CBCT imaging presented complete PBH. Regarding volumetric measurements on RD 3 years after REP for the change with respect to the baseline in root hard tissue volume, mean root hard tissue thickness, and apical area, the control group performed significantly in favor of RD than the test group (P = .03, .003, and 0.05 respectively). For the volumetric change 3 years after REP with respect to the baseline in root length and maximum root hard tissue thickness, no significant difference (P = .72 and .4, respectively) was found between the groups. The correlation between the PR and CBCT variables assessing RD was weak (root lengthening) to very weak (root thickening).

CONCLUSIONS

REP-LPRF seems to be a viable treatment option to obtain PBH and aid further RD of necrotic immature permanent teeth. Caution is needed when evaluating REP with PR.

Antibacterial Effect and Bioactivity of Innovative and Currently Used Intracanal Medicaments in Regenerative Endodontics

INTRODUCTION

The purpose of this study was to determine the antibacterial effect and bioactivity of triple antibiotic paste (TAP), calcium hydroxide (Ca[OH]₂), and calcium hypochlorite (Ca[OCl]₂).

METHODS

Root canals were infected with 3-week-old Enterococcus faecalis biofilm and then medicated for 7 days with TAP, Ca(OH)₂, or Ca(OCl)₂ (n = 10/group). Untreated and uninfected canals were used as positive and negative controls. The antibacterial effect was determined using colony-forming units and a Live/Dead bacterial viability kit. Dental pulp stem cells were seeded on medicated dentin surfaces for 7 days. Sodium thiosulfate and various concentrations of ascorbic acid (1%, 5%, and 10%) were also used to neutralize the samples treated with Ca(OCl)₂ before cell seeding (n = 3 in triplicate). Cell viability and morphology were evaluated using a viability assay and Live/Dead cell analysis. Alkaline phosphatase (ALP) activity was also measured to determine the cells' mineralization activity.

RESULTS

All medicaments decreased the initial bacterial load (P < .05). The highest bacterial reduction in the main canal and dentinal tubules was observed in the Ca(OCl)₂ group (P < .05). TAP- or Ca(OH)₂-treated dentin surface improved cell viability and ALP activity compared with the untreated dentin surface (P < .05), whereas Ca(OCl)₂ decreased cell viability and ALP activity (P < .05). Ten percent ascorbic acid neutralized the effect of Ca(OCl)₂ on the treated dentin surface, showing higher cell viability (P < .05) and similar ALP activity with the untreated dentin surface and the other groups (P > .05).

CONCLUSIONS

Ca(OCl)₂ medication improved root canal disinfection against E. faecalis biofilm compared with TAP and Ca(OH)₂. The adverse effects caused by Ca(OCl)₂ on cell viability and mineralization activity can be neutralized with 10% ascorbic acid.

Regenerative Endodontic Procedures: An Umbrella Review

The Regenerative Endodontic Procedure (REP) is a biologically based method in which a damaged pulp-dentin complex is replaced by a new vital tissue. This umbrella review aimed to critically assess the available systematic reviews (SRs) on REP. An electronic database search was conducted (PubMed-Medline, CENTRAL, Scielo, Web of Science, and LILACS) until December 2020. Studies were included if they were an SR on REP. The Risk of Bias (RoB) of SRs was analyzed using the Measurement Tool to Assess SRs criteria 2 (AMSTAR2). The primary outcome was the methodological quality in each specific section of REP protocols and outcomes. From 403 entries, 29 SRs were included. Regarding the methodological quality, ten studies were of critically low, three of low, fourteen of moderate, and two were rated as high quality. The quality of evidence produced by the available SRs was not favorable. Future high standard SRs and well-designed clinical trials are warranted to better elucidate the clinical protocols and outcomes of REP.

Nonsurgical Retreatment Using Regenerative Endodontic Protocols: A Case Report

AIM AND OBJECTIVE

The aim of this case report was to describe regenerative endodontic procedures (REPs) of the previously treated mature teeth with long-term results.

BACKGROUND

Regenerative endodontic procedures are aimed to treat apical periodontitis and regenerate the pulp-dentin complex in necrotic teeth. However, there is no consensus in using REPs in the previously treated mature teeth. The aim of this case report was to describe REPs of the previously treated mature teeth with long-term results.

CASE DESCRIPTION

A 25-year-old woman presented pain on chewing on 15 and swelling (WHO numbering system). The tooth had been endodontically treated and restored 4 years ago. After removing the old root canal filing, the roots were irrigated with 2.5% sodium hypochlorite and 17% EDTA using sonic activation. Calcium hydroxide (CH) was used as medicament for 3 weeks. At the second visit, CH was removed, and canals were irrigated as like as the first visit. Apical bleeding was induced, and concentrated growth factors (CGFs) were placed inside the root canal. The tooth has been followed up to 3 years.

CONCLUSION

The tooth was functional and asymptomatic at the recall visits. Since the first-year follow-up, the tooth responded to the electric pulp test and the thermal test. Radiological examinations revealed healing of apical lesion and hard tissue deposition.

CLINICAL SIGNIFICANCE

Regenerative endodontic procedures can offer an advantage over traditional endodontic procedures in terms of tertiary healing, with a predictable, user-friendly procedure also for retreatment cases.

Effect of mineral trioxide aggregate plug location on root development in regenerative endodontic procedure

This retrospective study investigated the effect of mineral trioxide aggregate (MTA) plug location on treatment outcome and root maturation after regenerative endodontic procedures (REP) in immature permanent teeth. Thirty-three roots (n = 33) in cohort that underwent REP consistently according to AAE guideline were included to trace radiographic changes for the root and canal dimensions. Based on intraoral radiographs, roots were divided into two groups depending on the location of MTA plug within whole root length: coronal group (n = 14), within the upper half; apical group (n = 19), within the lower half. Periapical radiographs were standardized to assess treatment outcomes and root maturation including root development stages and digital measurements on the change ratios of root length, apex width, radiographic root area (RRA), modified RRA (mRRA), and periapical rarefaction area. The data were statistically analysed using the Mann-Whitney test. The patients' average age was 11 years and 10 months, with no significant between-group difference in sex. Premolars were the most prevalent tooth type (62.1%), followed by incisiors and molars. Pre-existing symptoms and signs subsided within 6 months in all cases. The teeth showed similar radiographic root development in both groups (P > 0.05). However, mRRA increase ratio was significantly higher in apical group than that in coronal group at early (< 6 months) and late (< 24 months) periods of follow-up (P < 0.05). Significant changes of root development stage were observed at early period for apical group and at late period for coronal group (P < 0.05). All the observed cases showed continuing root development after REP. Significant changes in root developments occurred at different follow-up periods according to the location of MTA plugs.

Three-dimensional qualitative and quantitative analyses of the effect of periradicular lesions on the outcome of regenerative endodontic procedures: A prospective clinical study

OBJECTIVES

Qualitative and quantitative evaluation of the outcomes of regenerative endodontic procedure (REP) on human immature necrotic teeth with apical periodontitis using cone-beam computed tomography (CBCT) MATERIALS AND METHODS: Immature permanent teeth (n = 50) with necrotic pulp and periradicular pathosis were treated with a cell-homing concept-based REP. Following the procedure, a limited field-of-view CBCT scan was obtained. At each recall session (6, 12, 18 months), clinical tests were performed, and a digital periapical radiograph was taken. When significant radiographic changes were evident in the follow-up, a final CBCT scan was taken for qualitative and quantitative assessment. These initial and follow-up CBCT scans were assessed for quantification of changes in root length, pulp space diameter and periradicular lesion size. The data were statistically analysed using t test, one-way ANOVA, post hoc test and paired t test (P = 0.05).

RESULTS

Of the teeth, 94.6% were clinically successful based on the lack or regression of signs and symptoms after 48 months follow-up. REP resulted in a statistically significant increase in root length, decrease in pulp space diameter and periradicular radiolucency (P < 0.05). CBCT images illustrated various patterns of root maturation including an increased thickening of the canal walls and continued root maturation (37.1%), continued root development with the apical foramen remaining open (57.1%), severe calcification (obliteration) of the canal space (2.9%) and hard tissue barrier formation in the canal space between the coronal plug and the root apex (2.9%).

CONCLUSION

This study highlighted that the expected outcome of radiographic root development was less predictable when immature permanent teeth with periradicular pathosis were treated with REP.

CLINICAL RELEVANCE

The size and extent (expansion/destruction of the cortical plate) of periradicular lesions and abscesses influence the outcome of REP. These factors must be taken into consideration during treatment planning.

Regenerative endodontic therapy of immature permanent molars with pulp necrosis: a cases series and a literature review

AIM

To present the application and the outcome of the regenerative endodontic therapy (RET) in a series of symptomatic immature mandibular molars with pulp necrosis and apical periodontitis and to review the relevant literature for the documentation of the procedure as a potential treatment option.

METHODS

Three young male patients were referred with pain in the left mandibular region resulting from pulp necrosis and apical periodontitis of the first permanent molar. Regenerative endodontic approach was performed for the complete resolution of the lesions and the thickening of the apical root canal walls. The databases of Medline, Pubmed and Google Scholar were also searched for articles in which a regenerative approach has been undertaken for the endodontic management of immature permanent molars with pulp necrosis and apical periodontitis.

RESULTS

Follow-up examinations showed that the teeth remained functional without any signs or symptoms. Final radiographic examination at 12, 18 and 36 months, respectively, revealed complete resolution of the lesions and complete apical closure in the two out of three cases. The search of the literature revealed the existence of only 25 clinical articles in which necrotic immature molars were treated by the regenerative approach. The total number of the treated teeth were 46.

CONCLUSIONS

Regenerative endodontic approach may be applied in posterior non-vital molar teeth with a possible favorable outcome. However, the literature support for the documentation of the procedure as a predictable and reproducible treatment option in posterior immature molar teeth is at present limited.

Clinical Outcomes of Immature Teeth Treated with Regenerative Endodontic Procedures-A San Antonio Study

INTRODUCTION

Factors that influence clinical outcomes for regenerative endodontic procedures (REPs) are unknown. This retrospective study aimed to assess tooth healing, root development, pulp vitality, and esthetics post-REPs and categorize them into clinician- and patient-centered outcomes. Furthermore, this study identified significant predictors affecting such outcomes.

METHODS

Immature permanent teeth diagnosed with pulp necrosis treated with REPs between 2008 and 2018 with a minimum of 1-year follow-up were included. Outcomes included success and survival rates, changes in root development using 2-dimensional radiographic root area (RRA) and 3-dimensional measurements, pulp vitality, and tooth discoloration. Predictor variables of success included age, sex, etiology of pulp necrosis (PN), type of medicament, sodium hypochlorite (NaOCl) concentration, type of biomaterial used over the blood clot, and preoperative apical diagnosis. Statistical analyses included Cox proportional hazard analyses and generalized regression models.

RESULTS

Fifty-one teeth with an average of 2.1 years of follow-up satisfied the criteria. The survival rate was 92%. The success rate was 84.3% with age, etiology of PN, type of medicament, and NaOCl concentration being significant predictors of failure. Root development occurred in 91.4% of cases with age, sex, etiology of PN, type of medicament, NaOCl concentration, and apical diagnosis being significant predictors for RRA change. Positive pulp sensibility responses were associated with greater RRA change, and, finally, the type of biomaterial was a significant predictor for tooth discoloration after treatment.

CONCLUSIONS

REPs provide a high survival rate. Patient and clinical factors may affect outcomes, and this knowledge may help to define the criteria for optimal treatment planning of REPs.

Regenerative endodontics procedure of an immature permanent mandibular molar with a necrotic pulp using biodentine: a 16 months radiographic follow-up

An ideal scenario for a tooth in necrosis with immature root would be to continue root development after the regeneration of pulp tissue. We report a case, where the regenerative endodontic procedure (REP) was done using biodentine as a scaffold in an immature mandibular molar tooth.

Regenerative Endodontics for Upper Permanent Central Incisors after Traumatic Injury: Case Report with a 3-year Follow-up

AIM

The aim of this article is to describe a one-visit approach to attempt revascularization in the upper right and left central incisors after traumatic injury.

BACKGROUND

A single-visit conservative revascularization approach can be used to promote root growth and maturation following traumatic dental injury and loss of pulpal tissues.

CASE DESCRIPTION

An eight-year-old female patient presented in Dentalia Clinics, Jeddah, Kingdom of Saudi Arabia, in 2016 with traumatic dental injury. Upon clinical and radiographic examination, it was found that the trauma resulted in loss of pulp vitality in two upper central incisors. Local anesthesia was administered, and a rubber dam was placed. Access cavity was done for each tooth separately. 2% chlorhexidine followed by sterile saline was used for irrigation with no instrumentation. Mineral trioxide aggregate (MTA) was used as the sealing material after blood clot formation. Follow-up showed continuous root maturation in the right central incisor, at 6 months, one year, two years, and three years. Root canal treatment was done in 2019 due to the development of periapical lesion. The 6-month follow-up radiograph also showed loss of the crown of the left central incisor due to a second trauma with retained apical root fragment. The fragment was embedded inside the bone and showed continuous maturation during the three years.

CONCLUSION

A single-visit regenerative endodontic approach showed successful results in revascularizing the upper permanent central incisor after loss of pulpal tissue.

CLINICAL SIGNIFICANCE

Immature permanent teeth can be treated by a single-visit revascularization procedure to promote root maturation and increase in radicular dentin length and width.

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.

Enhanced Capability of Bone Morphogenetic Protein 2-loaded Mesoporous Calcium Silicate Scaffolds to Induce Odontogenic Differentiation of Human Dental Pulp Cells

INTRODUCTION

Calcium silicate bioceramics have been broadly used as reparative or grafting materials with good bioactivity and biocompatibility in dental application. It has been shown that applying a mesoporous process to calcium silicate gives it great potential as a controlled drug delivery system.

METHODS

The aim of this study was to investigate a novel osteoinductive scaffold by loading bone morphogenetic protein 2 (BMP-2) to mesoporous calcium silicate (MesoCS) and fabricating it as 3-dimensional scaffolds using fused deposition modeling combined with polycaprolactone.

RESULTS

The MesoCS/BMP-2 scaffold showed similar patterns to that of a calcium silicate scaffold in releasing calcium and silicon ions in a simulated body fluid (SBF) immersion test for 7 days, but BMP-2 continued releasing from the MesoCS/BMP-2 scaffold significantly more than the CS scaffold from 48 hours to 7 days. Adhesion and proliferation of human dental pulp cells cultured on a MesoCS/BMP-2 scaffold were also more significant than scaffolds without BMP-2 or mesoporous as well as the results of the test on alkaline phosphatase activity.

CONCLUSIONS

The results support that the novel 3-dimensional-printed MesoCS scaffold performed well as BMP-2 delivery system and would be an ideal odontoinductive biomaterial in regenerative endodontics.