Regenerative Endodontic Treatment Research Articles

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

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

A Combined Endodontic Management Approach in immature Permanent Molar tooth with Periapical Lesion: Case Report

Immature dental pulp, which has a highly cellular structure and a rich vascular nutrition system, is highly resistant to inflammation, In these teeth, determining the treatment option based on clinical and radiographic findings alone may result in the removal of diseased pulp tissue as well as vital pulp tissue. In order to increase the prognosis of these teeth, vital pulp treatments are highly recommended to preserve pulp vitality. By evaluating the condition of the root pulps of young permanent molars separately, it is possible to increase the prognosis of the tooth by combining regenerative endodontic treatment and pulpotomy treatment according to the condition of the pulps. In this case report, regenerative endodontic treatment and pulpotomy treatment were applied to different root canals of the first molar, which became necrotic before completing its maturation due to caries and had an apical lesion, and excellent healing was demonstrated. Key words: Biodentine, immature permanent teeth, periapical lesions, pulpotomy, regenerative endodontic treatment.

Effect of Low-Level Diode Laser and Red Light-Emitting Diode on Survival and Osteogenic/Odontogenic Differentiation of Human Dental Pulp Stem Cells.

Background: This investigation set out to compare the impacts of low-level diode laser (LLDL) and red light-emitting diode (LED) on the survival of human dental pulp stem cells (hDPSCs) and osteogenic/odontogenic differentiation. Methods and materials: In this ex vivo experimental study, the experimental groups underwent the irradiation of LLDL (4 J/cm2 energy density) and red LED in the osteogenic medium. Survival of hDPSCs was assessed after 24 and 48 h (n = 9) using the methyl thiazolyl tetrazolium (MTT) assay. The assessment of osteogenic/odontogenic differentiation was conducted using alizarin red staining (ARS; three repetitions). The investigation of osteogenic and odontogenic gene expression was performed at two time points, specifically 24 and 48 h (n = 12). This analysis was performed utilizing real-time reverse-transcription polymerase chain reaction (RT-PCR). The groups were compared at each time point using SPSS version 24. To analyze the data, the Mann-Whitney U test, analysis of variance, Tukey's test, and t-test were utilized. Results: The MTT assay showed that LLDL significantly decreased the survival of hDPSCs after 48 h, compared with other groups (p < 0.05). The qualitative results of ARS revealed that LLDL and red LED increased the osteogenic differentiation of hDPSCs. LLDL and red LED both upregulated the expression of osteogenic/odontogenic genes, including bone sialoprotein (BSP), alkaline phosphatase (ALP), dentin matrix protein 1 (DMP1), and dentin sialophosphoprotein (DSPP), in hDPSCs. The LLDL group exhibited a higher level of gene upregulation (p < 0.0001). Conclusions: The cell survival of hDPSCs was reduced, despite an increase in osteogenic/odontogenic activity. Clinical relevance: Introduction of noninvasive methods in regenerative endodontic treatments.

Regenerative Endodontic Procedures in Immature Teeth Affected by Regional Odontodysplasia

IntroductionRegional odontodysplasia (ROD) is a rare developmental disorder characterized by hypo-mineralization and hypoplasia of enamel and dentin. Symptoms include poorly developed tooth buds, delayed eruption of permanent teeth in affected quadrants, and ghost teeth. The affected teeth often become necrotic due to abnormal enamel and dentin development, making them susceptible to caries and infection. The aim of this case report is to describe the treatment of ROD through pulp revascularization. Case reportA 13-year-old girl was referred for endodontic treatment. The mandibular left incisors and first premolar, which were affected by regional odontodysplasia, lost their vitality because of the impaired structure of the enamel. Due to the teeth's early developmental stage, a regenerative endodontic treatment was attempted. All 3 teeth were treated using the same protocol following the AAE guidelines. After 4 weeks, treatment of the premolar was completed, whereas the incisor teeth remained symptomatic and were and therefore, intracanal dressing with calcium hydroxide was repeated and left in place for 5 months. Finally, the regenerative procedure was completed, and the crowns were restored. The patient was scheduled for follow-up examinations after 6 months, and then yearly for the next 3 years. After 1 year, the periapical lesion around the central incisor and premolar had resolved, the lesion around the apex of the lateral incisor was healing, and the roots had continued to develop. After 3 years, complete healing and pulp canal obliteration were observed in the central incisor and in the premolar. However, the root of the lateral incisor tooth was split, and it was recommended to extract this tooth. ConclusionThe positive outcomes of regenerative endodontics in the central incisor and premolar suggest that revascularization of the pulp may be optional for the treatment of immature necrotic teeth affected by developmental disorders, such as ROD, amelogenesis imperfecta, or dentinogenesis imperfecta.

Low‐intensity pulsed ultrasound induces proliferation of human neural stem cells

AbstractBackgroundLow‐intensity pulsed ultrasound (LIPUS) has been highlighted as a potential therapy for tissue repair and regeneration. However, little is known about LIPUS effects on neuromodulation. This research was conducted to study LIPUS effect on the proliferation of human neural stem cells.Materials and methodsThe human SH‐SY5Y neuroblastoma cell line was used as a neural stem cell model. The well‐documented SH‐SY5Y neurogenic protocol, which involves treatment with all trans‐retinoic acid (ATRA) for 5 days and then brain‐derived neurotrophic factor (BDNF) for 7 days, was used to synchronise the growth cell cycle to G1 phase of the cell cycle before proliferation testing. Subsequently, the neural stem cells were then treated with single or triple 20‐min LIPUS exposures (Intensity ISATA: 60 mW/cm2, frequency: 1.5 MHz, pulse repetition: 100 Hz, and duty cycle: 20%). Cell proliferation was analysed using cell counting of β‐tubulin and neurofilament medium‐positive neural stem cells, Ki67‐cell proliferation marker and metabolic‐based assays (cell counting kit‐8 and alamarBlue). The involvement of ERK signalling was investigated by quantification of phospho‐ERK1/2 levels and cell proliferation with and without MEK/ERK inhibitor (U0126).ResultsThe results show that LIPUS exposure(s) induced cell proliferation, as evidenced by an increase in the numbers of neural stem cells. ERK signalling is involved in LIPUS‐induced neural stem cell proliferation, as evidenced by concurrent inhibition of LIPUS‐induced phospho‐ERK levels and cell proliferation in the presence of the MEK/ERK inhibitor.ConclusionThis study provides original evidence that LIPUS can stimulate neural stem/progenitor cell proliferation. LIPUS may be suggested as a sole or an adjunct therapeutic application to promote the neural stem cell pool in stem cell therapies and tissue engineering approaches for nerve repair and regeneration for the management of traumatic nerve injuries and regenerative endodontic treatment.

Effect of magnesium oxide nanoparticles and LED irradiation on the viability and differentiation of human stem cells of the apical papilla.

Currently, regenerative endodontic treatments are gaining more and more attention, and stem cells play a significant role in these treatments. In order to enhance stem cell proliferation and differentiation, a variety of methods and materials have been used. The purpose of this study was to determine the effects of magnesium oxide nanoparticles and LED irradiation on the survival and differentiation of human stem cells from apical papilla. The MTT test was used to measure the cell survival of SCAPs that had been exposed to different concentrations of magnesium oxide nanoparticles after 24 and 48h, and the concentration with the highest cell survival rate was picked for further studies. The cells were classified into four distinct groups based on their treatment: (1) control, which received no exposure, (2) exposure to magnesium oxide nanoparticles, (3) exposure to light emitting diode (LED) irradiation (635nm, 200mW/cm2) for 30s, (4) exposure simultaneously with magnesium oxide nanoparticles and LED irradiation. A green approach was employed to synthesize magnesium oxide nanoparticles. Quantitative real time PCR was used to measure the gene expression of osteo/odontogenic markers such as BSP, DSPP, ALP and DMP1 in all four groups after treatment, and Alizarin red S staining (ARS) was used to determine the osteogenic differentiation of SCAPs by demonstrating the Matrix mineralization. The highest viability of SCAPs was observed after 24h in concentration 1 and 10µg/mL and after 48h in concentration 1µg/mL, which were not significantly different from the control group. In both times, the survival of SCAPs decreased with increasing concentration of magnesium oxide nanoparticles (MgONPs). According to the results of Real-time PCR, after 24 and 48h, the highest differentiation of BSP, DMP1, ALP and DSPP genes was observed in the LED + MgONPs group, followed by MgONPs and then LED, and in all 3 experimental groups, it was significantly higher than control group (P < 0.05). Also, after 24 and 48h, the density of ARS increased in all groups compared to the control group, and the highest density was observed in the MgONPs + LED and MgONPs groups. This research concluded that exposure to SCAPs, MgONPs, and LED irradiation has a significant effect on enhancing gene expression of odontogenic/osteogenic markers and increasing matrix mineralization.

Outcomes of Regenerative Endodontic Treatment Performed Using Different Magnification Devices: A Systematic Review.

In this systematic review, we assessed whether the effects of the usage of various devices help with magnification in endodontics and whether they resulted in any significant changes in the clinical result of treatment. An exhaustive search was performed across MEDLINE and Cochrane Registers for various clinical studies, which were focused on comparing regenerative endodontic treatment based on the usage of magnification devices. Various terms were used to search these clinical trials such as microscope, regenerative endodontic surgery, apicoectomy, endoscope, and loupes. After scrutinizing the studies, around three clinical trials based on magnification in endodontic surgeries were included in the present review. It was observed that no statistically noteworthy betterment of treatment outcome was seen in patients treated with either of the magnification devices such as loupes and microscope. It was evident that these magnification devices can alter the effectiveness of regenerative endodontic treatment in a very minimal way. However, we believe that more randomized clinical studies should be conducted in this area.

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

IntroductionModern tissue engineering strategies have elucidated the potential of regenerative endodontic treatment (RET) as an alternative for treating mature teeth. MethodsHere, 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. ResultsAfter 5 years of follow-up, the healing response was satisfactory in both cases, with evidence of pulp revitalization. ConclusionsThis 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.

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.

Management of Failed Regenerative Endodontic Treatment of a Necrotic Immature Molar: A Case Report With 12-Month Follow Up

Introduction: Management of necrotic immature permanent teeth has always posed a challenge to clinicians. Regenerative endodontic procedures (REPs) have been proposed as an alternative to apexification to treat necrotic immature teeth. However, few failed cases of REPs have been presented in the literature with different successful retreatment approaches. Case presentation: An eight-year-old boy reported spontaneous pain in the right permanent mandibular first molar. Regenerative endodontic treatment using platelet-rich fibrin (PRF) was the treatment method due to the open apices. At the 9-month follow-up, there was a periapical lesion around the distal root. Hence, apexification with Mineral trioxide aggregate (MTA) was carried out. In the twelve-month follow-up, the periapical lesion healed radiographically. Conclusions: MTA and bioceramic-based root canal sealers yielded satisfactory outcomes in lesion healing. Little is known about the biological and clinical aspects of regenerative endodontic treatment. Moreover, there are still unknown factors that govern the success of REPs.

Laser Applications in Regenerative Endodontics: A Review.

Introduction: Developing regenerative endodontic treatment (RET) is an exciting approach to managing immature permanent teeth with pulp necrosis. RET is usually performed in two clinical steps: disinfection (first step) and tissue engineering (second step). Recently, laser therapy has entered the field of RET. This study aimed to provide an overview of the literature that employed laser therapy for root regeneration. Methods: A comprehensive search was performed on four databases, including PubMed, Web of Science, Scopus, and Google Scholar. The searched keywords were laser, regenerative endodontics, immature permanent teeth, and dental pulp necrosis, and related English-published articles were included up to October 2023. Results: Thirteen studies utilized a laser for RET. In the first step of RET, both high-power and low-level lasers (through photodynamic therapy [PDT]) may be applied for canal disinfection. In contrast, regenerative procedures in the second step of RET are just accelerated by low-power lasers (biostimulation). The literature does not support the benefit of laser-assisted irrigation in improving the clinical success of RET. There is some evidence that laser-assisted disinfection with a diode laser may provide comparable results to triple antibiotic paste in reducing bacterial counts in root canals while providing slightly better clinical and radiographic outcomes. PDT may be an effective and suitable adjunct to conventional disinfection methods in immature, necrotic teeth. Conclusion: Low-power lasers may be beneficial tools for improving the results of regenerative endodontics through chemical disinfection in the first step (PDT) or by biostimulation in the second step of RET.

Evaluation of cytotoxicity of 3.8 % SDF and BioAKT solutions on the viability of dental pulp stem cells

IntroductionNonsurgical endodontic therapies have evolved from classic endodontic therapies to regenerative endodontic treatments (RETs) in recent years. In context of the cytotoxic activity of the most commonly used endodontic irrigant, NaOCl, newer endodontic irrigating solutions should be tested for its effective use in RETs. The aim of this trial was to examine and assess the cytotoxic response of 3.8 % SDF and BioAKT irrigating solutions on the viability of DPSCs. MethodsThe viability of DPSCs cultivated in 5.25 % NaOCl, 3.8 % SDF & BioAKT at dilutions of 1:100,1:20 &1:10 were evaluated through MTT assay after 10 min, 60 min and 24 h incubation, detection of apoptosis and ALP activity after 7,14 & 21-days incubation. A two-way analysis of variance (ANOVA) with post hoc Turkey HSD was performed to determine significant differences between the specimens tested. ResultsWhen compared to the control at all time periods, all test specimens at varied dilutions (1:100, 1:20, and 1:10) caused no cytotoxic effects. The maximum number of live cells and ALP activity was observed with DPSCs cultivated in BioAKT followed by 3.8 % SDF and 5.25 % NaOCl at all time intervals. ConclusionDifferent doses of 3.8 % SDF and BioAKT solution revealed encouraging outcomes when compared to 5.25 % NaOCl in terms of viability, proliferation and long-term ALP functioning potential when cultivated in DPSCs.

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

IntroductionThe 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. MethodsFifty 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. ResultsThe 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). ConclusionsAccording 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.

Regenerative Endodontic Treatment of Previously Treated Mature Permanent Tooth: A Case Report with 3-year Follow Up

Regenerative Endodontic Treatment of Previously Treated Mature Permanent Tooth: A Case Report with 3-year Follow Up

3-YEAR FOLLOW-UP OF REGENERATIVE ENDODONTIC TREATMENTS WITH THE APPLICATION OF CONCENTRATED GROWTH FACTOR AS SCAFFOLD: NINE CASES

The aim of this case series is to present 3-year clinical and radiographic follow-ups of nine regenerative endodontic treatment cases using concentrated growth factor in necrotic immature permanent teeth. Nine patients aged 8-21 years were referred to our clinic. According to clinical and radiographic examinations, it was decided to perform RET. After the working length determination, teeth were irrigated with 2.5% NaOCl and activated with EndoActivator. Root canals were instrumented with XP-endo Finisher-R file. 20 mL of 17% EDTA was used as final irrigation, and calcium hydroxide and temporary fillings were placed. Two weeks later, roots were irrigated with 17% EDTA and 5 mL distilled water and dried with paper points. Bleeding was induced into the coronal part of the root canal. Concentrated growth factor (obtained from the patient’s blood) was placed into the root canals. Biodentine was placed on the blood clot and permanent restorations were made with resin composite. At 3-year follow-up, clinical and radiographic healing was observed in 5 patients. In the other 4 patients, persistent infection and sinus-tract formation were detected at different time periods. Although RET is a promising treatment that aims to preserve teeth vitally, more randomized clinical research is needed due to its unpredictable results.

Effect of Platelet Rich Plasma in Regenerative Endodontic Treatment: A Review of Clinical Trials

Endodontic treatments are emerging solutions using biological materials in the field of reconstructive dentistry. Platelet-rich plasma (PRP) with numerous properties in the repair of body tissues has attracted the attention of many researchers. Hence, this systematic review study was carried out to evaluate the effect of PRP in regenerative endodontic treatment. The present systematic review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statements. Until April 2023, PubMed/Medline, Web of Science, Scopus, and Google Scholar databases were searched using the relevant keywords including “Platelet Rich Plasma”, “Plasma, Platelet-Rich”, “Regenerative Endodontic”, “Endodontic, Regenerative”, and “Endodontics, Regenerative”. Of 186 identified records through database searching, 5 randomized controlled trials (RCTs) were included in this systematic review. The sample size in RCTs varied between 53 and 338. The range of subject’s age was from 13 to 67. Overall, the evidence of this review revealed that PRP plays an important role in healing of teeth with endodontic problems through regeneration of their soft and hard tissues. Overall, PRP seems to be effective in regeneration and healing of damaged dental tissues. However, further high quality assessments are required for demonstrating therapeutic role of PRP in regenerative endodontic.

Exploring the impact of oral bacteria remnants on stem cells from the Apical papilla: mineralization potential and inflammatory response.

Bacterial persistence is considered one of the main causal factors for regenerative endodontic treatment (RET) failure in immature permanent teeth. This interference is claimed to be caused by the interaction of bacteria that reside in the root canal with the stem cells that are one of the essentials for RET. The aim of the study was to investigate whether prolonged exposure of stem cells from the apical papilla (SCAP) to bacterial remnants of Fusobacterium nucleatum, Actinomyces gerensceriae, Slackia exigua, Enterococcus faecalis, Peptostreptococcaceae yurii, commonly found in infected traumatized root canals, and the probiotic bacteria Lactobacillus gasseri and Limosilactobacillus reuteri, can alter SCAP's inflammatory response and mineralization potential. To assess the effect of bacterial remnants on SCAP, we used UV-C-inactivated bacteria (as cell wall-associated virulence factors) and bacterial DNA. Histochemical staining using Osteoimage Mineralization Assay and Alizarin Red analysis was performed to study SCAP mineralization, while inflammatory and osteo/odontogenic-related responses of SCAPs were assessed with Multiplex ELISA. We showed that mineralization promotion was greater with UV C-inactivated bacteria compared to bacterial DNA. Immunofluorescence analysis detected that the early mineralization marker alkaline phosphatase (ALP) was increased by the level of E. coli lipopolysaccharide (LPS) positive control in the case of UV-C-inactivated bacteria; meanwhile, DNA treatment decreased the level of ALP compared to the positive control. SCAP's secretome assessed with Multiplex ELISA showed the upregulation of pro-inflammatory factors IL-6, IL-8, GM-CSF, IL-1b, neurotrophic factor BDNF, and angiogenic factor VEGF, induced by UV-C-killed bacteria. The results suggest that long term stimulation (for 21 days) of SCAP with UV-C-inactivated bacteria stimulate their mineralization and inflammatory response, while DNA influence has no such effect, which opens up new ideas about the nature of RET failure.

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

AimThis 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).MethodA 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.ResultsLower 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.ConclusionThis 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.

Discussion on the common issue about regenerative endodontic treatment, apexification or apical barrier

Regenerative endodontic treatment, apexification or apical barrier can all eliminate the signs and symptoms induced by pulp necrosis with or without apical periodontitis of young permanent teeth, and promote the healing of bone lesions. Although regenerative endodontic treatment may promote the continued development of the root in affected teeth, it is difficult to predict the prognosis as influenced by various factors. And calcification is common after regenerative endodontic treatment. Moreover, the views that apexification may increase the risk of root fracture and that apexification or apical barrier cannot promote the further development of the roots are biased. For some cases, apexification or apical barrier are still good choices. In clinic, when the treatment plan is made, the factors such as the medical condition of the patients, the degree of root development of the affected teeth, the cause and the course of diseases, the amount of residual dental tissues should be fully considered to obtain the best prognosis for the affected teeth.

A Comparative Evaluation of Biological Scaffold in Regenerative Endodontic Treatment of Immature Non-Vital Permanent Teeth

Endodontic treatments techniques for immature necrotic teeth include: surgical endodontics, apexification, and singlevisit MTA plug. Regenerative endodontic therapy (RET) is a newer concept that involves restoring the pulp-dentin complex in an infected tooth with an open apex. The aims of this paper were to evaluate RET of immature permanent teeth using biological scaffold and the distinctions between them, with a focus on their ease of manipulation and regenerative potential.