Apical Barrier Research Articles

Three-dimensional printed apical barrier model technology for pre-clinical dental education.

Clinically, apical barrier procedure can be adopted to create an immediate artificial barrier for tooth with an open apex. Given that the quality of the barrier is crucial, the apical barrier procedure is known for its high technical sensitivity, posing significant learning challenges for dental students. Therefore, a new dental teaching model not only effectively enhances the future clinical skills of dental students but also benefits a wider range of patients. A new dental model for simulating apical barrier procedure in vitro, is helpful for dental students to practice apical barrier procedure. This study aims to design, assess, and evaluate the feasibility of a three-dimensional (3D) printed apical barrier model for pre-clinical dental education. A novel 3D-printed apical barrier model was developed, consisting of a tooth model and a matching blind box. Total 200 3D-printed apical barrier models were used to train dental students, and fifty fifth-year dental students participated in this voluntary hands-on course. Each student performed apical barrier procedures on four 3D-printed models. The outcome of the first model served as the representative result for the "direct barrier group", whereas the outcome of the fourth model represented the result of the "post-training barrier group". The quality of the apical barrier procedure was assessed through X-ray examination, and a questionnaire was used to evaluate the 3D-printed model's benefits, with scores ranging from 1 (strongly agree) to 5 (strongly disagree). The overall rating for the 3D-printed model was 2.0 ± 0.6. The model was noted for its high degree of realism, ease of use, and practical applicability. Post-training assessments showed significant improvements in the density of apical barrier fillings (P< 0.05), reduction in underfilling rates (P< 0.05), and decrease in overfilling distances (P< 0.05). Students overwhelmingly agreed that the model was beneficial for training in apical barrier procedures (1.06 ± 0.24), helped identify their shortcomings (1.62 ± 0.53), and improved their operational skills (1.90 ± 0.51). Both the questionnaire feedback and the quality of the fillings confirmed the feasibility and efficacy of the 3D-printed apical barrier model for dental education. The students had the possibility to learn the correct apical barrier procedure on printed dental models.

A Case Report of Root Resorption after Tooth Dislocation Replantation

The complete dislocation of the right upper central incisor lasted for more than 2 hours. After 2 weeks of replantation, the ligature was removed. After 1.5 months of reexamination, it was found that the internal and external root absorption of the affected tooth could be slowed down through infection control in the root canal and apical barrier. Reexamination 2.5 months later showed increased bone density around the root of the affected tooth.

Evaluation of microleakage of mineral trioxide aggregate and biodentine as apical barriers in simulated young permanent teeth

BackgroundApexification is a procedure that promotes apical closure by forming mineralized tissue in the apex region of a nonvital young permanent tooth. Calcium silicate-based cement like Mineral trioxide aggregate (MTA) and Biodentine are commonly employed as apical barriers to facilitate this process. Microleakage, defined as the leakage along the junction between the canal wall and filling material, is a crucial aspect to assess in MTA and Biodentine applications as apical barriers, as it directly impacts the prevention of bacterial seepage and maintenance of structural integrity. The current study aims to assess the microleakage of MTA and Biodentine when used as apical barriers in simulated young permanent teeth.MethodsFrom a total of 128 extracted teeth, 114 were selected for the study and randomly allocated into three groups: G1 (MTA), G2 (Biodentine), and G3 (Control), with 38 teeth per group. After excluding 5 teeth from each group due to issues such as canal calcification, breakage during sectioning, and procedural errors, 33 teeth were analyzed to ensure equal distribution. To simulate young permanent teeth, samples were instrumented using a person-reamer with a diameter of 1.7 mm. A 4 mm thick apical plug of MTA and Biodentine was placed in G1 and G2, respectively, while G3 was the control group. Apical microleakage in all experimental groups was assessed using a dye penetration method. Specimens were longitudinally sectioned and examined under a stereomicroscope with graded eyepiece.ResultsThe Kruskal-Wallis test revealed variations in mean apical microleakage among the groups: G1 recorded 0.67, G2–0.16, and G3–1.62, with G2 showing the lowest value and G3 group exhibiting the highest.ConclusionsBiodentine was found to excel in its ability to create a secure seal and function effectively as an apical barrier in simulated young permanent teeth. These results underscore its potential as a highly efficient material for dental applications, particularly in scenarios requiring reliable sealing and barrier formation in the root canal system of developing permanent teeth.

Milk Exosome-Liposome Hybrid Vesicles with Self-Adapting Surface Properties Overcome the Sequential Absorption Barriers for Oral Delivery of Peptides.

Milk exosomes (mExos) have demonstrated significant promise as vehicles for the oral administration of protein and peptide drugs owing to their superior capacity to traverse epithelial barriers. Nevertheless, certain challenges persist due to their intrinsic characteristics, including suboptimal drug loading efficiency, inadequate mucus penetration capability, and susceptibility to membrane protein loss. Herein, a hybrid vesicle with self-adaptive surface properties (mExos@DSPE-Hyd-PMPC) was designed by fusing functionalized liposomes with natural mExos, aiming to overcome the limitations associated with mExos and unlock their full potential in oral peptide delivery. The surface property transformation of mExos@DSPE-Hyd-PMPC was achieved by introducing a pH-sensitive hydrazone bond between the highly hydrophilic zwitterionic polymer and the phospholipids, utilizing the pH microenvironment on the jejunum surface. In comparison to natural mExos, hybrid vesicles exhibited a 2.4-fold enhancement in the encapsulation efficiency of the semaglutide (SET). The hydrophilic and neutrally charged surfaces of mExos@DSPE-Hyd-PMPC in the jejunal lumen exhibited improved preservation of membrane proteins and efficient traversal of the mucus barrier. Upon reaching the surface of jejunal epithelial cells, the highly retained membrane proteins and positively charged surfaces of the hybrid vesicle efficiently overcame the apical barrier, the intracellular transport barrier, and the basolateral exocytosis barrier. The self-adaptive surface properties of the hybrid vesicle resulted in an oral bioavailability of 8.7% and notably enhanced the pharmacological therapeutic effects. This study successfully addresses some limitations of natural mExos and holds promise for overcoming the sequential absorption barriers associated with the oral delivery of peptides.

Treatment outcomes and prognostic factors of the apical barrier technique with premixed calcium silicate-based putty in necrotic permanent teeth with open apices: a retrospective cohort study with up to six years follow-up.

To evaluate treatment outcomes of the apical barrier technique with premixed calcium silicate-based putty for treating necrotic permanent teeth with open apices and to identify prognostic factors. Permanent teeth with necrotic pulps and open apices treated by the apical barrier technique with premixed calcium silicate-based putty, with a minimum follow-up of 12 months, were included. Treatment outcomes were based on clinical signs, symptoms, and radiographic evaluation. The treatment outcome was dichotomized into success or failure according to strict and loose criteria. The chi-square test (or Fisher's exact test) and multiple logistic regression analysis were used to evaluate possible prognostic factors associated with treatment outcomes. Seventy-four teeth with a follow-up time of 12-72 months (mean, 25.74 ± 14.36 months) were included in the final evaluation. The success rate was 97.30% using the loose criteria and 66.22% using the strict criteria. Multiple logistic regression analysis indicated that the size of pre-operative periapical lesion (≥ 5mm) (odds ratio [OR]: 18.96; P = 0.0153) and root canal underfilling (OR: 8.341; P = 0.0448) were significant predictors for treatment failure under the strict criteria. The apical barrier technique with premixed calcium silicate-based putty is a highly successful procedure for treating necrotic permanent teeth with open apices after an observation period of up to 6 years. Treatment success under the strict criteria is primarily affected by the size of the pre-operative periapical lesion and the apical extent of root-filling. Careful case selection and ensuring adequate root filling quality are essential to the successful outcome of the apical barrier technique with premixed calcium silicate-based putty.

Evaluation of Marginal Adaptation of Three Biomaterials as Apical Barrier in Experimental Apexification Model

Aim: The purpose of this study was to compare the marginal adaptation of Mineral Trioxide Aggregate (MTA), Biodentine, and EndoSequence as apical plug materials after orthograde placement in an experimental apexification model using confocal laser scanning microscopy (CLSM). Material and Methods: The study was conducted with sixty single-rooted mature mandibular premolar teeth. These teeth were prepared as 12 mm root lengths, and apical regions of teeth were enlarged by using peeso reamers to give the open apex form likely with the immature teeth as an experimental apexification model. ProRoot MTA, Biodentine, and EndoSequence used as apical plug materials were placed into the apical region of samples with a thickness of 4 mm. After filling the remaining root canal with gutta-percha, each sample was divided into three transverse sections by using a hard tissue microtome to evaluate marginal adaptation between dentine walls and apical plug material using a confocal laser scanning microscopy. Then, gap areas of all microscope images were measured with Image J program. Results: MTA showed the highest marginal adaptation, followed by EndoSequence and Biodentine. Biodentine was significantly inferior to the other materials in marginal adaptation (p0.01). Conclusion: MTA and EndoSequence exhibited superior marginal adaptation as apical plugs compared to Biodentine. Biodentine had the poorest adaptation among the three materials.

Platelet-rich fibrin as an apical barrier for MTA placement in the treatment of teeth with open apices: a pilot study

ObjectiveThe aim of the present pilot study was to assess the effectiveness of the platelet-rich fibrin (PRF) apical barrier for the placement of MTA for the treatment of teeth with periapical lesions and open apices.MethodsA total of thirty teeth on twenty-eight patients with open apices and periapical periodontitis were enrolled and divided into two groups in the present pilot study. In the PRF group (fourteen teeth in thirteen patients), nonsurgical endodontic treatment was performed using PRF as an apical matrix, after which the apical plug of the MTA was created. For the non-PRF group (fourteen teeth in fourteen patients), nonsurgical endodontic therapy was performed using only the MTA for an apical plug with no further periapical intervention. Clinical findings and periapical digital radiographs were used for evaluating the healing progress after periodic follow-ups of 1, 3, 6, and 9 months. The horizontal dimension of the periapical lesion was gauged, and the changes in the dimensions were recorded each time. The Friedman test, Dunn-Bonferroni post hoc correction, and Mann-Whitney U test were used for statistical analysis, with P < 0.05 serving as the threshold for determining statistical significance.ResultsAll patients in both groups in the present pilot study had no clinical symptoms after 1 month, with a significant reduction in the periapical lesion after periodic appointments. The lesion width of the PRF group was significantly smaller than that of the non-PRF group in the sixth and ninth month after treatment.ConclusionsPRF is a promising apical barrier matrix when combined with MTA for the treatment of teeth with open apices and periapical periodontitis. Small number of study subjects and the short time of follow-up period limit the generalizability of these results.Trial registrationTCTR, TCTR20221109006. Registered 09 November 2022 - Retrospectively registered, https://www.thaiclinicaltrials.org/show/TCTR20221109006.

Histologic Assessment of a Fast-Set Mineral Trioxide Aggregate (MTA) and Two Novel Antibacterial-Enhanced Fast-Set MTAs for Apexification and Periapical Healing of Teeth With Incomplete Root Formation in a Rat Model: An In Vivo Animal Study.

Background Pulp necrosis in incomplete root formation halts dentine development, resulting in larger canals with fragile walls and an open apex, complicating canal instrumentation and apical stop formation. Bioactive endodontic cements such as mineral trioxide aggregate (MTA) are crucial for creating artificial apical barriers or inducing apical foramen closure, but challenges remain regarding their antimicrobial efficacy and cytotoxicity. Modifications to MTA formulations aim to address these concerns. Methods This in vivo animal study involved 80 Wistar albino rats, with incomplete root formation induced by pulp exposure. Rats were divided into four groups receiving different MTA formulations for apexification: conventional MTA, modified MTA, and MTA enhanced with metronidazole or doxycycline. Histopathological evaluations were conducted at seven and 28 days post-treatment to assess calcific barrier formation, inflammatory reactions, and antimicrobial efficacy. Results By day 7, modified MTA formulations exhibited enhanced antibacterial activity compared to conventional MTA(p = 0.000), with fewer inflammatory reactions and microorganisms. By day 28, modified formulations showed superior calcific barrier formation, particularly in the metronidazole-and doxycycline-enhanced groups compared to conventional MTA (p = 0.000). These outcomes suggest that modifications to MTA formulations improve antimicrobial efficacy and calcific barrier formation in vivo. Conclusion Novel modified MTA formulations, particularly those enhanced with metronidazole or doxycycline, exhibit superior antibacterial efficacy and calcific barrier formation compared to conventional MTA. Further long-term studies are warranted to validate these findings for potential clinical translation.

Clinical study of iRoot-BP combined with collagen sponge in treatment of periapical inflammation

The purpose of this research was to observe the clinical effect of iRoot-BP combined with collagen sponge for the treatment of periapical inflammation with lesions larger than 10 mm and undeveloped apical foramen. 26 teeth from 25 patients with periapical inflammation meeting the inclusion criteria were randomly assigned into two groups with 13 teeth per group. In collagen sponge group, the apical barrier was performed using iRoot-BP combined with collagen sponge, and in non-collagen sponge group was only treated with iRoot-BP. Patients in two groups were followed up at 3, 6 and 12 months respectively, and the therapeutic effect was judged according to the clinical and imaging findings. The prognosis of periapical lesions indicated that there were 13 of treated teeth in collagen sponge group and 11 of treated teeth in non-collagen sponge group show no signs of clinical or radiographic failure (χ2 = 2.167, p = 0.14). The observation results of continued root growth suggested that the average root growth of collagen group was 2 mm, while no continuous root growth was observed in non-collagen sponge group (p &lt; 0.05). Application of iRoot-BP combined with collagen sponge has obvious advantages in treatment of large-scale periapical inflammation with undeveloped apical foramen, which can promote the formation of immature roots closer to the normal roots.

Platelet rich fibrin and MTA in the treatment of teeth with open apices

BackgroundThe present study aimed to evaluate the effectiveness of using platelet-rich fibrin (PRF) as the apical matrix for the placement of MTA in nonsurgical endodontic therapy for teeth with periapical lesions and open apices.MethodsTwelve teeth from eleven patients with periapical periodontitis and open apices were enrolled in the study. Nonsurgical endodontic therapy was performed with the PRF used as an apical barrier and the MTA manipulated as an apical plug for further thermoplasticized gutta percha in the remaining part of the root canal. Clinical signs and periapical digital radiographs were recorded and analyzed to evaluate the curing progress after periodical follow-ups of 1, 3, and 6 months. The horizontal dimension of the periapical lesion was determined, and the changes in the dimensions were recorded each time. The Friedman test was used for statistical analysis, with P < .05 serving as the threshold for determining statistical significance.ResultsAll patients had no clinical symptoms after the first month of treatment, with a significant reduction in the periapical lesion after periodical appointments.ConclusionsPRF is an effective barrier when combined with MTA for the treatment of teeth with periapical periodontitis and open apices.

Management Strategies for Immature Teeth with Pulp Necrosis: An Umbrella Review of Systematic Reviews.

This review evaluates the effectiveness of treatment modalities for immature teeth with pulp necrosis, focusing on calcium hydroxide (CH) and mineral trioxide aggregate (MTA) apexification, as well as regenerative endodontic treatments (RETs). Recent advancements and clinical outcomes are highlighted. A comprehensive search of MEDLINE (PubMed), Embase, Cochrane Library, Scopus, and grey literature was conducted from inception to July 2024. Systematic reviews and meta-analyses (SR/MAs) assessing apexification and RET outcomes in immature teeth with pulp necrosis were included. Studies were selected based on predefined criteria, and data on study design, interventions, and outcomes were extracted. Methodological quality was evaluated using the AMSTAR-2 tool. 31 SR/MAs were included. The quality ranged from critically low to low, except one rated as high. MTA apexification was more effective than CH for faster apical barrier formation, though overall success rates were similar. MTA is preferred for its efficiency, but standardized protocols are needed, and tooth discoloration was noted as a potential complication. RET generally outperforms apexification in root maturation, with platelet concentrates like platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) showing promising results; PRP was associated with greater root length, while PRF showed superior apical healing. Variability in RET outcomes was noted due to the lack of standardized protocols. Comparative studies of RET versus apexification showed no significant differences in survival or overall success rates. RET often provides better apical closure and root development, though results vary. Both approaches are viable, but more research with standardized protocols and larger samples is needed to establish definitive clinical advantages. MTA apexification and RET are viable alternatives to CH apexification, with RET showing greater potential for root development and apical healing. Future research should focus on developing standardized protocols and uniform RET guidelines, and evaluating long-term outcomes to establish efficacy and safety.

Six-year clinical evaluation of iRoot BP Plus as apical barrier in permanent teeth of periapical periodontitis.

The apical barrier technique in permanent teeth with extensive destruction of the periapical tissue and a long infection time is much more difficult to succeed, which is a clinical challenge. This study aimed to evaluate the long-term effects of iRoot BP Plus as an apical material in adult teeth. Fifty incisors and premolars were chosen for this study. All teeth were performed apical barrier with the same operator. After treatment, the teeth were clinically and radiographically evaluated at 1, 2 and 6 years. At the 1-year follow-up, 35 teeth had healed, and three patients developed an apical abscess due to root fracture at the 2-year follow-up. Six years postoperatively, one tooth showed root resorption, which was considered a failure. The long clinical evaluation confirmed that iRoot BP Plus is a suitable material for the apical barrier of mature teeth with open apices and periapical lesions.

Microstructural Evaluation of the Mineralized Apical Barrier Induced by a Calcium Hydroxide Paste Containing Iodoform: A Case Report

IntroductionA 65-year-old man had nonsurgical retreatment using an iodoform and calcium hydroxide paste in a maxillary left canine with persistent apical periodontitis. An apical mineralized barrier (AMB) was observed 3-months postoperatively. Unfortunately, the tooth was extracted due to a cementum tear. This provided an opportunity to analyze the AMB histologically, as there is a lack of previous reports on its microstructure. MethodsAfter extraction and removal of the granulation tissue from the root surface, the canine was processed, and observed using micro–computed tomography (μCT) and light microscopy. Thereafter, the specimen was resin-embedded specimen was evaluated by scanning electron microscopy, micro–X-ray fluorescence spectroscopy and Raman spectroscopy to understand the mechanism and nature of the AMB formation during apical healing. ResultsNonsurgical retreatment was clinically successful based on the absence of clinical symptoms of apical periodontitis and the radiographic presence of an AMB. The AMB was opaque and could be readily differentiated from dentin under a light microscope. Micro–computed tomography analysis revealed that the AMB had the same mineral density as dentin. Scanning electron microscopy revealed that the AMB had two distinct layers based on the size of the calcified particles. Elemental mapping using micro–X-ray fluorescence spectroscopy showed that the localization of calcium and phosphorus differed between AMB and other areas of biomineralization. Raman spectral mapping revealed that the surface layer of the AMB consisted of collagen, calcium carbonate, and hydroxyapatite. ConclusionsThis study explored new analytical methods for elucidating the apical wound-healing process and the nature of the mineralized repair. The findings provided detailed information on the AMB highlighting a bilaminar structure with high calcium components higher on the inside and a brightness similar to cementum not dentin and the presence of hydroxyapatite.

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.

Management of an Ellis Class IV fracture with open apex using MTA -A case report

Management of immature necrotic permanent teeth imposes a challenge to the clinician as they cannot be managed with routine endodontic treatment. To treat such a tooth; thorough disinfection of the root canal system followed by an apical barrier to obturate the canal is required. This case report demonstrates management of an anterior necrotic tooth with an open apex using Mineral Trioxide Aggregate (MTA) for apexification. The tooth was thoroughly disinfected using antimicrobial irrigants. Calcium hydroxide dressing was given for a period of 1 week followed by an apical plug of 4-5 mm of MTA. A fiber post and composite core were given to finally restore the tooth with a full coverage crown. The positive clinical outcome of the case supports the use of MTA apexification for the management of open apex.

Regenerative endodontic treatment of immature permanent teeth after mechanical instrumentation with XP-Endo Finisher.

The traditional treatment of immature permanent teeth with necrotic pulp involves creating an apical barrier by using calcium hydroxide or an MTA plug for an extended period of time. A novel therapeutic approach called regenerative endodontic procedures (REP) is used to allow root development to continue.

Clinical applications of calcium silicate-based materials: a narrative review.

Calcium silicate-based materials are hydrophilic materials with biocompatibility and bioactivity properties. Despite many advantages, they might present some problems related to discolouration, setting time, manipulation and solubility depending on the composition of the product and the type of clinical application. Calcium silicate-based materials can be evaluated under two types according to their intended use: calcium silicate-based cements (CSCs) and calcium silicate-based sealers (CSSs). CSCs can be used in many endodontic procedures including perforation repair, resorption repair, apical barriers, guided endodontic repair, vital pulp treatment, endodontic surgery, root fractures and root canal filling as a core obturation material. CSSs are available for use with gutta-percha to obturate root canals using cold and warm techniques, including the sealer-based obturation technique. The purpose of this review is to evaluate the available literature on CSCs and CSSs and to provide up-to-date information and recommendations for their clinical applications.

SURGICAL REMOVAL OF SUPERNUMERARY TOOTH FOLLOWED BY ORTHODONTIC TRACTION OF PERMANENT CENTRAL INCISOR BY FIXED APPLIANCE THERAPY

Management of immature root with a necrotic pulp and apical periodontitis is a challenging task. Obturation of the root canal is difficult because of lack of apical barrier for containing the root filling material. Treatment of choice in such cases is the apexification procedure, i.e., establishing an apical barrier. Calcium hydroxide has been widely used for the induction of hard tissue barrier. However, this material requires 5-20 months to form the hard tissue barrier. It has also been shown that the use of calcium hydroxide weakens the resistance of the dentin to fracture. In recent times, mineral trioxide aggregate (MTA) has gained widespread popularity for the apexification procedure. It produces apical hard tissue formation with significantly greater consistency than calcium hydroxide.MTA, a biocompatible material, can be used to create a physical barrier. It also helps in the formation of bone and periodontium around its interface.

The Differences of the Calcium Hydroxide and the Mineral Trioxide Aggregate in the Apical Closure of Immature, Non-Vital Permanent Teeth

When an immature tooth comes into contact with trauma, the dental pulp in the developing tooth can die, which can cause the absence of root and apical closure. Apexification is a technique used to repair these abnormalities. This method allows us to promote the growth of a hardened root end block. MTA and Ca (OH)2 are two materials that can be used in this process. Either MTA or calcium hydroxide have a good chance of producing positive clinical results. MTA is favored over calcium hydroxide for its significantly shorter time for apical barrier formation, low solubility, easy approach, and ability to prevent root fracture, while calcium hydroxide is preferred over MTA for root length elongation in open apex teeth. The limitations of calcium hydroxide include the fact that it takes more time and multiple visits to form the root-end barrier, is more prone to fracture, and has the potential for reinfection. The goal of this review is to collect revisions on inducing root formation and synthetic barrier approaches and consider the advantages and disadvantages of calcium hydroxide versus MTA.

Effects of Apical Barriers and Root Filling Materials on Stress Distribution in Immature Teeth: Finite Element Analysis Study

PurposeA finite element analysis (FEA) study was performed to determine whether the material of apical barrier used for root apexification and/or the use of canal reinforcement affect the stress distribution in an endodontically treated immature permanent tooth in order to infer in which clinical scenarios a fracture is more likely to occur based on the ultimate tensile strength threshold of dentin. Methods and MaterialsAn extracted human immature mandibular premolar was selected as the reference model and scanned by micro-computed tomography (micro-CT). The digital model was segmented and converted to STL (Standard Tessellation Language) using Simpleware Scan-IP and exported in IGES (Initial Graphics Exchange Specification) to Ansys 19. Six experimental models were designed with different combinations of composite, mineral trioxide aggregate (MTA), and Biodentine (BIO). Using FEA, a static 300 N load at a 135 angle with respect to the axis of the tooth was applied to each model and von Mises stress values (MPa) were measured at the sagittal, apical 8-mm, 5-mm, 2-mm, and 1-mm levels. ResultsIn all regions examined, the control (NT model) had lower stress in the root compared WITH experimental models. At the mid-root level, models with composite, MTA, and BIO reinforcement exhibited lower stresses in the root dentin than those with pulp or gutta-percha. BIO models had equal or greater average von Mises stress values than those of MTA models in all regions. Both, MTA and BIO, caused increases in stress of surrounding root dentin, with BIO causing a greater increase than MTA. ConclusionsStress distribution in immature permanent teeth treated by apexification is affected by the types of materials used. Root dentin's stress was lower when the mid-root canal was reinforced by composite, MTA, or BIO, which provided similar stress reduction to the root dentin. MTA is a more favorable apical barrier material from a mechanical standpoint because it induces less stress on apical root dentin than BIO.