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.

The potential use of ascorbic acid to recover the cellular senescence of lipopolysaccharide-induced human apical papilla cells: an in vitro study.

OBJECTIVES: To examine the effect of lipopolysaccharide (LPS) on cellular senescence induction of human apical papilla cells (hAPCs) and evaluate the potential use of 50 µg/ml ascorbic acid to recover cellular senescence and regenerative functions. MATERIALS AND METHODS: hAPCs were treated with LPS at 1 and 10 µg/ml either with or without 50 µg/ml ascorbic acid for 48 h. The cellular senescence biomarkers were analyzed by senescence-associated ß-galactosidase (SA-ß-gal) staining and senescence-related gene expression, p16 and p21. Cell migration, at 12 h and 24 h, was evaluated using a scratch wound assay. Mineralization potential was assessed at 21 days using Alizarin red S staining and dentine sialophosphoprotein (DSPP) and bone sialoprotein (BSP) gene expression. RESULTS: 1 µg/ml and 10 µg/ml LPS stimulation for 48 h induced cellular senescence, as shown by remarkable SA-ß-gal staining and p16 and p21 gene expression. The percentage of wound closure and mineralized formation was reduced. The co-incubation with ascorbic acid significantly down-regulated the level of SA-ß-gal staining. The reduction of senescence-associated gene expressions was observed. Ascorbic acid improved cell migration, mineralized nodule formation, and the expression of DSPP and BSP genes in LPS-treated hAPCs. CONCLUSIONS: LPS significantly promoted cellular senescence on hAPCs and diminished the cell function capacity. Co-presence of ascorbic acid could impede cellular senescence and possibly improve the regenerative capacity of LPS-induced senescent hAPCs in vitro. CLINICAL RELEVANCE: The data support the in vitro potential benefit of ascorbic acid on cellular senescence recovery of apical papilla cells.

Histologic and radiological observations of a human immature premolar with pulp necrosis treated with regenerative endodontic procedure - A case report of a four-year follow-up.

Background: Reports are found on long-term radiographic follow-up of teeth treated with regenerative endodontic techniques, but scarce literature is observed regarding the tissue formed in the root canal. A four-year radiographic follow-up with histologic findings in an immature mandibular premolar with dens evaginatus that underwent a regenerative endodontic procedure (REP) is presented here. After four years following REP, the tooth was extracted for orthodontic purposes thereby presenting an opportunity to report the histologic findings. Summary: The radiographic changes included a slight root lengthening and thickening and apex closure. Histologic evaluation revealed a fibrous connective tissue with an inflammatory infiltrate in the canal space. In the apical region, cementum-like irregular mineralization developed toward the center, giving the appearance of a closed apex. Root thickening, increase in length, and radiographic closure of the apex occurred due to cemental hyperplasia. Conclusion: After 4 years following REP in an immature mandibular premolar with apical periodontitis, granulation tissue had formed in the root canal, indicating repair and not regeneration.

Apexification with a bioceramic reparative cement: a case report.

The aim of this case report is to describe the treatment of a maxillary right central incisor with pulpal necrosis and incomplete root formation. The 14-year-old patient had experienced trauma to both maxillary central incisors approximately 2 years earlier. Therapy consisted of apexification with a bioceramic reparative cement to form an apical plug. After the clinical and radiographic evaluations, the clinician opened the crown, performed the chemical-mechanical preparation, and placed calcium hydroxide-based medication. At the next appointment, 24 days later, the intracanal medication was removed through passive ultrasonic instrumentation; the canal was dried; and the bioceramic cement was inserted into the apical portion with the aid of a mineral trioxide aggregate holder. A sterile cotton ball, moistened with distilled water, was used to maneuver the material in the apical region, and a periapical radiograph was exposed to confirm the correct placement of the bioceramic reparative cement. The canal was filled with gutta percha cones and a bioceramic root canal sealer. All procedures were performed with the aid of microscopic magnification. Clinical and radiographic evaluations at the 18-month follow-up visit showed that the treated tooth was asymptomatic, suggesting that the bioceramic reparative cement is effective for apexification.

Different endodontic treatments induced root development of two nonvital immature teeth in the same patient: A case report.

BACKGROUND: Pulp revascularization is a novel way to treat immature teeth with periapical disease, and the technique has become increasingly well established in recent years. By puncturing the periapical tissue, bleeding is induced, and a blood clot is formed in the root canal. The blood clot acts as a natural bioscaffold onto which mesenchymal stem cells from periapical tissue can be seeded and restore pulp vascularity, thus promoting root development as well as apical closure. Although the effect of pulp revascularization is ideal, there are certain requirements for the apical condition of the teeth. The apical barrier technique and apexification are still indispensable for teeth that cannot achieve ideal blood clot formation. In addition, a meta-analysis of several clinical studies concluded that pulp revascularization has no significant advantages over other treatments. CASE SUMMARY: A 10-year-old girl complained of pain in the right upper and lower posterior teeth for 2 d. Clinical and radiological examinations revealed that both the right maxillary and mandibular second premolars were immature with periapical radiolucency. The right maxillary second premolar was treated by pulp revascularization, while the right mandibular second premolar was treated by conventional apical barrier surgery after revascularization failed. The purpose of this report is to compare the different root maturation processes induced by the pulp revascularization and apical barrier techniques in the same patient in homonymous teeth from different jaws. Twelve months of follow-up showed that the apical foramen of both teeth presented a clear tendency to close; however, the tooth treated with pulp revascularization showed a significant increase in root length as well as root canal wall thickness. CONCLUSION: For the treatment of nonvital immature teeth, pulp revascularization showed a superior therapeutic effect in comparison with the apical barrier technique.

Outcome of Regenerative Endodontic Procedures in Nonvital Immature Permanent Teeth Using 2 Intracanal Medications: A Prospective Randomized Clinical Study.

INTRODUCTION: This randomized clinical trial aimed to assess and compare the long-term clinical and radiographic outcomes of regenerative endodontic procedures (REPs) in treating nonvital immature permanent teeth using 2 intracanal medicaments. METHODS: Forty-five patients yielding a total of 50 anterior and posterior nonvital immature teeth were randomly divided into 2 groups. REPs using either nonsetting calcium hydroxide (Ca[OH]2) (n = 25) or modified triple antibiotic paste (TAP) (n = 25) as intracanal medicaments were performed. NeoMTA Plus (Avalon Biomed Inc) was applied for coronal sealing. Cases were followed up clinically and radiographically for 36 months. The survival rate, success rate, and clinical outcome measures were analyzed. Preoperative and recall radiographs were evaluated for dimensional changes in root length, dentin thickness, apical diameter, and periapical radiolucency. RESULTS: At the 36-month follow-up, the success and survival rates were 81.6% and 100%, respectively, in which 79.4% of cases showed complete resolution of periapical radiolucency with no significant difference between the nonsetting Ca(OH)2 and modified TAP groups (P > .050). The cumulative changes in root length, root dentin thickness, and apical diameter throughout the study period were observed in 47.9%, 77.1%, and 89.6% of cases, respectively, with no significant differences between groups (P ≥ .39). Intracanal calcifications were detected in 60% of cases with no significant difference between groups (P = .77). CONCLUSIONS: REPs, using either nonsetting Ca(OH)2 or modified TAP as the intracanal medicament, exhibited high success and survival rates over a follow-up period of 36 months with equally favorable clinical and radiographic outcome data.

The Effect of General Anesthesia on the Outcome of Root Canal Treatment in Pediatric Patients-A Retrospective Cohort Study.

This study aimed to evaluate the effect of general anesthesia (GA) on the 1-year outcome of Root Canal Treatment (RCT) performed in pediatric patients and to compare it to the outcome of RCT in pediatric patients without GA. Patients admitted for RCT in permanent dentition in a public hospital, dated 2015 to 2020, age 8-15 with a minimum of one year follow-up period, were included in the study. The sample consisted of 326 teeth from 269 patients treated by a single operator, with a recall rate of 81%. Overall, 124 teeth were treated under GA and 142 teeth were without GA. The mean follow-up time was 31.5 months. Data underwent statistical analysis and the significance threshold was set for p < 0.05. Of the total cases, 90% showed favorable outcomes. A significantly higher favorable outcome was seen in the GA group than in the non-GA group (98% and 85%, respectively, p < 0.001). The outcome was significantly affected by the type and quality of the coronal restoration, degree of root development, and lesion size (p < 0.05). According to the current study, in uncooperative pediatric patients, a more favorable outcome of root canal treatment can be obtained under GA than LA if the procedure is carried out with immediate restoration.

Root Maturation of an Immature Dens Invaginatus Despite Unsuccessful Revitalization Procedure: A Case Report and Recommendations for Educational Purposes.

BACKGROUND: The clinical management of teeth with complex dens invaginatus (DI) malformations and apical periodontitis may be challenging due to the lack of routine. The aim of this case report is to describe the endodontic treatment of an immature tooth with DI and to discuss strategies for preclinical training for teeth with such malformations. CASE REPORT: A 9-year-old male presented with an immature maxillary incisor with DI (Oehlers Type II) and apical periodontitis which was diagnosed by cone beam computed tomography (CBCT). Revitalization was initially attempted but then abandoned after failure to generate a stable blood clot. Nevertheless, considerable increase in both root length and thickness could be detected after medication with calcium hydroxide followed by root canal filling with MTA as an apical plug. CONCLUSIONS: The endodontic management of teeth with DI requires thorough treatment planning. In immature teeth, under certain conditions, root maturation may occur even with conventional apexification procedures. From an educational perspective, different strategies including CBCT and 3D-printed transparent tooth models for visualization of the complex internal morphology and redesigned 3D-printed replica with various degrees of difficulty for endodontic training, can be used to overcome the challenges associated with endodontic treatment of such teeth.

Success and Complication Rates of Revascularization Procedures for Immature Necrotic Teeth: A Systematic Review.

Frequently, adolescents exhibit instances of immature necrotic teeth, which are identifiable by their slender root walls and unclosed root tips. The lack of a natural narrowing near the root's end creates difficulty when using standard endodontic procedures, making the effective sealing of the immature root canal difficult or impractical. Revascularization therapy surfaces as a prospective strategy for addressing the management of undeveloped, non-vital, immature, necrotic teeth. Notwithstanding this, apexification continues to hold prominence in the preferences of clinicians owing to its perceived predictability in treatment outcomes. A systematic investigation was conducted involving various search engines and databases, covering the period from 2001 to 2023. The main aim of this investigation was to find randomized clinical trials that compared the efficacy of revascularization therapy to apexification for treating immature necrotic teeth. The evaluation included a thorough examination of both clinical and radiographic outcomes assessing the success rates and complications. Out of the 850 identified articles, 15 studies were chosen for comprehensive analysis. Notable dissimilarities were not identified between the revascularization therapy and apexification groups concerning parameters such as rates of periapical healing, overall effectiveness/invalidation, and apical closure. However, concentrating on measurable factors, it became clear that the revascularization treatment group displayed a notable rise in root length compared to the apexification group. Both revascularization endodontic therapy and apexification demonstrated effectiveness in addressing periapical periodontitis healing and open apex closure. Pulp revascularization stood out for its notable efficacy in enhancing root elongation and thickening, all while having a reduced likelihood of treatment being deemed ineffective overall.

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

BACKGROUND: The effectiveness of platelet concentrates in promoting root development of necrotic immature permanent teeth is unclear. The present study evaluated whether the platelet concentrate protocol was superior to the traditional blood clot protocol in regeneration therapy. METHODS: We searched Electronic databases, such as PubMed, Cochrane Library, ClinicalTrials and EMBASE. Randomized controlled trial studies, cohort studies, case-control studies and cross-sectional studies were included, in which platelet-rich concentrates were tested for periapical healing and root development, with the blood clot treatment protocol as the control group. Clinical and radiographic outcomes were considered. Selected articles were assessed for risk of bias. Pooled risk ratios (risk ratio, RR) were calculated for clinical success, responses to cold and electric pulp tests, periapical lesions, apex closure, root lengthening, and thickening of the dentin walls. Subgroup meta-analysis were conducted according to the type of platelet concentrate used. RESULTS: Of the 1272 screened studies, 13 randomized controlled studies, 2 case-control studies and 1 cohort study were selected, in which 465 immature necrotic permanent teeth, particularly incisors and premolars, were treated. Of these 465 teeth, 457 (98.2%) in both the control and experimental groups remained clinically asymptomatic for the entire study duration, whereas eight (1.8%) showed signs and symptoms of failure, including spontaneous pain, sensitivity to percussion or reinfection. Compared with control teeth, teeth treated with PRP achieved better apical healing than BC group (RR 1.13, 95% CI 1.01-1.26, P = 0.03), and teeth treated with platelet concentrates showed improved apical closure (RR 1.04, 95% CI 0.86-1.25, P = 0.69), root lengthening (RR 1.01, 95% CI 0.74-1.39, P = 0.93), and thickening of the dentin walls (RR 1.35, 95% CI 0.95-1.93, P = 0.09), although these differences were not statistically significant. CONCLUSIONS: Platelet concentrates can be used as successful scaffolds for regenerative endodontic treatment of necrotic immature permanent teeth, and PRP as a scaffold may achieve better periapical healing of teeth with periapical inflammation, although they did not differ significantly from conventional blood clot scaffolds in development of the root.

Management of Ellis Class-IV Fractured Tooth With an Open Apex: A Case Report.

Dental professionals face difficulty in managing "immature non-vital teeth with an open apex." It is considered to be challenging because, in this situation, root canal filling material should be confined within the boundaries of the root canal without extruding peri-apically. Apexification tries to create a hard tissue barrier that will cause the open apex to close, allowing root filling to be compacted. The current case report describes the application of mineral trioxide aggregate (MTA) to create an apical plug in an open apex, as MTA is considered a versatile material for apexification, which was followed by the reinforcing of the weekend root using glass fiber post and core build-up to manage the Ellis class IV fracture.

Direct pulp capping of carious immature tooth using bioactive material: A case report.

The management of deep carious lesions in immature tooth and the preservation of its pulp vitality is a real challenge in daily dental practice. Bioactive cements are of interest to deal with such cases. Our case report describes the immediate management and the follow-up of an extensive carious lesion on an immature first right mandibular molar with pulp exposure by direct pulp capping using Biodentine. A 6-month clinical and radiographic follow up showed that the tooth was vital, with dentine-bridge formation in the pulp chamber with continuous root formation. This procedure allowed the protection of pulp complex, preserving at the same time its functional and biologic activities due to the capacities of Biodentine as an effective pulp capping material to induce pulp cells to form hard tissue. The aim of this article is to discuss through the report of this clinical case, the indications, advantages and disadvantages of different procedures and biomaterials used for direct pulp capping.

"Meta-analysis of regenerative endodontics outcomes with antibiotics pastes and calcium hydroxide. The apex of the iceberg".

PORPOSE: The aim of this study was to evaluate, through a meta-analysis, the predictability of Regenerative Endodontic therapies with antibiotic pastes and calcium hydroxide [Ca(OH)2], related to four variables as follows: root dentin wall thickening, apical closure, apical repair and root lengthening. METHODS: Literature electronic searches were performed in Pubmed - MEDLINE, Scopus and Lilacs-BVS platforms using appropriate search terms, Mesh (Medical Subject Headings), DeCS (Health Sciences Descriptors) and Boolean operators comprising articles published between 2009 and 2020. Thirty-two original indexed papers were included making a total of 758 regenerative endodontic procedures. A descriptive meta-analysis was performed. RESULTS: Dentin wall thickening was present in 66% (CI95: 58%-73%) of the cases treated with antibiotic paste, while when Ca(OH)2 was used, a percentage of 53% (CI95: 26%-78%), was obtained. When antibiotic paste was used, apical closure was found in the 66% (CI95: 58%-73%) of the regenerative endodontic procedures, while when Ca(OH)2 was used, 88% (CI95: 80%-93%) of the cases were found to reach apical closure. Root lengthening and apical repair were found satisfactory for both disinfection protocols. CONCLUSIONS: There could be differences between the two treatments since a higher percentage of root dentin wall thickening was found when using antibiotic pastes, while a higher percentage of apical closure was found when calcium hydroxide was used. Development of more clinical studies would be necessary in order to confirm the observed differences. The proposed approach could provide a useful contribution for endodontists when planning regenerative endodontic procedures, so as to guide decision-making to the best elective treatment and to select the appropriate disinfection method in accordance with preoperative radiographic diagnosis of root development stage, then increasing the predictability of regenerative endodontic treatment and reducing potential risk of root fractures.

Effect of hydrogel-based antibiotic intracanal medicaments on crown discoloration.

OBJECTIVES: This study evaluated the effects of low and moderate concentrations of triple antibiotic paste (TAP) and double antibiotic paste (DAP) loaded into a hydrogel system on crown discoloration and explored whether application of an adhesive bonding agent prevented crown discoloration. MATERIALS AND METHODS: Intact human molars (n = 160) were horizontally sectioned 1 mm apical to the cementoenamel junction. The crowns were randomized into 8 experimental groups (calcium hydroxide, Ca[OH]2; 1, 10, and 1,000 mg/mL TAP and DAP; and no medicament. The pulp chambers in half of the samples were coated with an adhesive bonding agent before receiving the intracanal medicament. Color changes (ΔE) were detected by spectrophotometry after 1 day, 1 week, and 4 weeks, and after 5,000 thermal cycles, with ΔE = 3.7 as a perceptible threshold. The 1-sample t-test was used to determine the significance of color changes relative to 3.7. Analysis of variance was used to evaluate the effects of treatment, adhesive, and time on color change, and the level of significance was p < 0.05. RESULTS: Ca(OH)2 and 1 and 10 mg/mL DAP did not cause clinically perceivable tooth discoloration. Adhesive agent use significantly decreased tooth discoloration in the 1,000 mg/mL TAP group up to 4 weeks. However, adhesive use did not significantly improve coronal discoloration after thermocycling when 1,000 mg/mL TAP was used. CONCLUSIONS: Ca(OH)2 and 1 and 10 mg/mL DAP showed no clinical discoloration. Using an adhesive significantly improved coronal discoloration up to 4 weeks with 1,000 mg/mL TAP.

A three-dimensional finite element analysis of permanent maxillary central incisors in different stages of root development and trauma settings.

BACKGROUND AND OBJECTIVES: Differences in dental maturation may affect the prognosis and clinical management of traumatized teeth. However, evaluation of the outcomes of dental trauma to the tooth and support structures in an in vivo model involves major methodological and ethical implications. Thus, the aim of the present study was to perform a three-dimensional finite element analysis of permanent maxillary central incisors in different stages of root development under different trauma settings. METHODS: The study factors included two trauma conditions (B, buccal; I, incisal) on upper permanent central incisors showing three different stages of root development (CR, complete rhizogenesis; IRA; incomplete rhizogenesis in the apical third of the root; and IRM, incomplete rhizogenesis in the middle third of the root) to yield six models. The complete rhizogenesis model was obtained with a cone-beam computed tomography examination of an extracted tooth. The two incomplete rhizogenesis models were modeled on the basis of similar examinations of patients. Trauma was simulated by applying a 300 N static surface to surface load on the incisal edge or perpendicular to the buccal surface of the tooth. The displacement and equivalent von Mises (σvM) stress values were obtained for alveolar bone, periodontal ligament, apical papilla, and dentin for the quantitative analysis. A σvM color-coded scale was used for qualitative analysis. RESULTS: The force direction had a greater influence on the stress than the root-formation stage. Buccal forces resulted in higher stress concentration in the bone and periodontal ligament, especially in B-CR. Lower stress was found on the periodontal ligament as the root formation progressed (decrease of 8% from B-IRA to B-CR and 11% from B-IRM to B-CR). The incomplete rhizogenesis models showed higher σvM stress peak values in dentin in comparison with complete rhizogenesis (increase of 52% from B-CR to B-IRA and 56% from B-CR to B-IRM). CONCLUSIONS: Buccal forces yielded greater stress values regardless of the stage of rhizogenesis. Teeth with fully formed roots showed a higher stress concentration in the alveolar bone and periodontal ligament in comparison with immature teeth, with the latter presenting high stresses in the tooth crown.

Apical pressures generated by several canal irrigation methods: A laboratory study in a maxillary central incisor with an open apex.

AIM: A laboratory study to determine the apical pressure generated by seven canal irrigation methods in an anterior tooth with an open apex. METHODOLOGY: Canal irrigation was performed on a 3D-printed central maxillary incisor with an open apex (maximum diameter of 2.1 mm). Ultrasonically activated irrigation (UAI), sonic activation (EDDY), negative pressure irrigation (EndoVac), the self-adjusting file (SAF) and the XP-endo Finisher were employed at tooth length (TL), TL-1 mm, TL-2 mm and TL-3 mm. UAI was tested at three intensity levels additionally. Hydrodynamic irrigation with RinsEndo was performed in the pulp chamber, at the canal orifice, the coronal third, the middle of the canal and at TL. Er:YAG laser activation, at four frequency settings, was performed in the pulp chamber and at the orifice of the canal. The pressure of the fluid towards the canal terminus generated by activation was directly transferred to a pressure sensor with a range of 0 to 120 mmHg and a response time of ≤0.5 ms. The critical threshold for apical extrusion of the irrigant was set at 5.73 mmHg (lower limit of the central venous pressure: 5.88 ± 0.15 mmHg). Each experiment was repeated ten times. The tests were followed by descriptive analyses (maximum, mean, standard deviation, 95% confidence interval). RESULTS: EndoVac, the SAF, the XP-endo Finisher, and UAI never exceeded the critical threshold at any insertion depth or intensity level. Er:YAG laser activation exceeded the critical threshold exclusively at frequency settings that varied from the manufacturer's recommendation. EDDY at TL and RinsEndo at any insertion depth exceeded the critical threshold in 100% of the measurements. EDDY at TL-1,-2, and-3 mm crossed the critical threshold in 30%, 10%, and 20% of the measurements, respectively. CONCLUSIONS: In a simulated maxillary central incisor with an open apex, irrigation with EndoVac, Er:YAG laser activation, UAI, the SAF, and the XP-endo Finisher generated apical pressures below the critical threshold of 5.73 mmHg. By contrast, using EDDY and RinsEndo for irrigation produced higher apical pressures that exceeded the critical threshold.

Clinical and Radiographic Outcomes of Immature Teeth Treated with Different Treatment Protocols of Regenerative Endodontic Procedures: A Retrospective Cohort Study.

Regenerative endodontic procedure (REP) is a progressive treatment modality for immature permanent teeth with necrotic pulp. The ambiguousness about the predictability of REP outcome in relation to complete disinfection of the root canal system and the occurrence of discoloration still exists. The aim of this retrospective study was to analyze two treatment protocols on clinical success rate, radiographic root development and the occurrence of discoloration. Eighteen patients were treated by a single operator by either treatment protocol according to the American Association of Endodontists (AAEP, n = 9) or a modified protocol (MP, n = 9) with the use of 5% sodium hypochlorite and sandblasting. Patients were followed up after 3, 6, 9, 12, 18 and 24 months and clinical success, radiographic root development and the occurrence of discoloration were assessed. The clinical success of MP was significantly higher in two years follow-up (p = 0.015), but the change in radiographic root area was higher for AAEP (p = 0.017) and the occurrence of discoloration was higher in AAEP (p = 0.029). The use of 5% sodium hypochlorite for a longer period of time leads to a higher success rate. The sandblasting of the access cavity reduces the occurrence of discoloration.

Effect of revascularisation and apexification procedures on biomechanical behaviour of immature maxillary central incisor teeth: a three-dimensional finite element analysis study.

OBJECTIVES: This study aimed to assess the effects of revascularisation and apexification procedures on biomechanical behaviour of immature teeth using 3-dimensional finite element analysis (3D FEA). MATERIALS AND METHODS: Five 3D FEA permanent maxillary incisor models were developed from CBCT scans and available literature data: Model MT: Mature tooth, Model IT: Immature tooth (Cvek's stage 3), Model AT: Apexified tooth-mineral trioxide aggregate (MTA) apexification, Model RTB: Revascularised tooth with blood, and Model RTS: Revascularised tooth with supplementary scaffold. Using FEA, a masticatory load of 240N at 120° was simulated, and the Von Mises and maximum principal stresses within the models were evaluated. Failure index (FI) and weakening% were also calculated for each model. RESULTS: On dentinal stress analysis, model MT (96.16MPa) and IT (158.38MPa) had lowest and highest stress values, respectively. Among the experimental groups, model RTS (131.12MPa) had lower stresses than AT (136.33MPa) and RTB (133.7MPa), with no significant difference among the three. Peak dentinal stresses in all the models were observed in the cervical third of the root and near the apical opening in model IT. The extent of high dentinal stress area in model RTB and RTS was lesser than that of AT. The FI and weakening% values were highest for model AT followed by RTB and RTS, among the experimental groups. However, all these treatments strengthened an immature tooth by more than 20%. CONCLUSIONS: AT, RTB, and RTS treatments lowered the stress values and risk of fracture in immature teeth with no significant difference among the three groups. CLINICAL RELEVANCE: Stress distribution evaluation following revascularisation/apexification was essential, with potential to influence clinical decision-making. MTA apexification and revascularisation with blood clot/supplementary scaffold lowered the stresses in immature teeth, with no significant difference among the three.

Effect of apexification on occlusal resistance of immature teeth.

BACKGROUND: Strain distribution was investigated to assess the occlusal resistance alterations in immature teeth under different occlusal force. METHODS: In vitro apexification models of teeth with a funnel-shaped immature apex were obturated with mineral trioxide aggregate (MTA; ProRoot MTA) using different combinations of core materials (10/group): group 1, full-length orthograde obturation of MTA; group 2, a 5-mm MTA apical plug with a composite core; group 3, a 5-mm MTA apical plug and back-filling with warm gutta-percha. Teeth with calcium hydroxide (CH)-medicated canals and untreated teeth with normal apices were tested as controls. The teeth were arranged between two adjacent normal-apex teeth, embedded in a resin mold with a simulated periodontal ligament space. Strain data were recorded from the 3-unit teeth assembly under static compressive occlusal forces (50, 100, 200, and 300 N). Measurements were repeated 20 times for each condition, and the data were statistically analyzed. RESULTS: The immature teeth showed altered occlusal force resistance, placing increased strain on adjacent teeth. Teeth with CH-medicated canals showed significantly inferior occlusal resistance under all tested forces (P < 0.05). Application of an MTA plug with deep composite resin core resulted in significantly better stress-bearing capacity especially under forces of 50 and 300 N (P < 0.05). CONCLUSIONS: The pattern of occlusal force distribution in immature teeth differed according to the canal obturation materials used for apexification. Immature teeth with an MTA apical plug showed more favorable occlusal force resistance than those with CH-medicated canals.

Comparative evaluation of calcium release of the apical plugs formed by mineral trioxide aggregate, Biodentine, and EndoSequence root repair material with and without 2% triple antibiotic powder: An in vitro study.

BACKGROUND: Apical plug formation by mineral trioxide aggregate (MTA), Biodentine, and EndoSequence root repair material (RRM) is an excellent alternative technique to the conventional apexification procedure. Several antimicrobial agents have been incorporated in MTA and Biodentine to boost their antimicrobial efficacy. Considering the polymicrobial nature of root canal infection, a combination of potent antimicrobials like triple antibiotic powder (TAP) would be needed to address the diverse flora encountered. Calcium release is the consequential factor in the clinical excellence of these cements. AIM: The aim of the study was to evaluate and compare the calcium released from the apical plugs formed by MTA, Biodentine, and EndoSequence RRM with and without incorporation of 2% TAP. METHODS: Ninety single-rooted teeth were divided into (n = 15) Group A: MTA + 2% TAP, Group B: MTA, Group C: Biodentine + 2% TAP, Group D: Biodentine, Group E: EndoSequence RRM + 2% TAP, and Group F: EndoSequence RRM to form the 4 mm apical plugs. Each sample tooth was then immersed in 10 ml of deionized water. Evaluation of calcium release was done on days 7, 15, and 30 using an atomic absorption spectrophotometer. Data were analyzed using one-way analysis of variance, post hoc test, and unpaired t-test. RESULTS: Calcium released was maximum for Group E compared to Group F (P < 0.05), maximum for Group C compared to Group D, and was maximum for Group A compared to Group B (P < 0.05) at days 7, 15 and 30. CONCLUSION: Incorporation of 2% TAP resulted in increased calcium ions released from MTA, Biodentine, and EndoSequence RRM.