Regenerative endodontic treatment of necrotic permanent teeth with pre-eruptive intracoronal radiolucency: a case report.

Pre-eruptive intracoronal radiolucency is a rare dental anomaly with unclear aetiology, generally asymptomatic and diagnosed through routine radiographs. Failure to diagnose and treat it early can lead to rapid pulp damage, potentially compromising root development. The presented clinical report describes a mandibular second premolar with pre-eruptive intracoronal radiolucency that caused early pulp necrosis with arrest of root formation and emphasises the endodontic management using regenerative endodontic therapy.

Revascularization of a Previously Treated Mandibular First Molar with Open Apices: A Case Report.

In this case report, the regeneration method was used to treat the previously treated first molar, which presented with symptoms of pain during chewing and secondary acute apical periodontitis. Due to the importance of preserving the patient's permanent teeth in order to maintain optimal space and function, the regeneration treatment was performed in two visits and according to the American Association of Endodontists (AAE) guidelines. The continuation of tooth root development, healing of periapical radiolucency and positive response to sensibility test (cold test) were observed during follow-up radiographs at intervals of 6 months, 1 year & 2 year.

Modified single-step apexification and strengthening of thin dentinal walls with Biodentine.

Apexification is a technique used to create a mineralized barrier in a root having an open apex or to continue the apical growth of a root that is still not fully developed in teeth with necrotic pulps. Biodentine is a versatile material which can help in achieving apical closure as well as reinforcement of thin dentinal walls, thus improving the overall prognosis and preserving the natural dentition. In the present case, the radiographic evaluation showed thinner dentinal walls and an open apex with periapical radiolucency in relation to the upper right central incisor. The large open root apex and thin dentin walls of immature permanent teeth render them challenging to treat with root canal therapy. This case report describes a modified single-step apexification procedure and strengthening of the dentinal walls of the root canal using Biodentine.

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

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

Endodontic treatments on permanent teeth in pediatric patients aged 6-12 years old.

Backgroud/purpose: The prevalence of carious lesions and traumatic injury in individuals between ages 6 and 12 is high. This study aimed to characterize pediatric patients aged 6-12 treated in the endodontic clinic and investigate the prevalence and patterns of their provided endodontic treatments. Materials and methods: Clinical and radiographic records of patients (ages 6-12) referred to the postgraduate Endodontics clinic from June 2017 to June 2020 were reviewed. Demographics, pre-and post-operative conditions, type of endodontic treatment, and behavioral management were collected. Results: A total of 6350 teeth from 6089 patients were treated in this period, and 425 teeth (6.7%) from 405 patients were included. Ages 9-11 were the most commonly treated age group. Significantly more lower molars (41.9%) and upper anterior teeth (36.7%) were treated (P < 0.05). The majority of teeth were diagnosed with pulp necrosis (39.5%), and the most common periapical diagnosis was normal apical tissues (39.8%), then symptomatic apical periodontitis (38.8%). The most common etiological factor was caries (63.5%). Two hundred six teeth (48.5%) were treated with root canal therapy, 161 teeth (37.9%) with vital pulp therapy, 46 teeth (10.8%) with apexification or regenerative endodontic procedure, 12 teeth (2.8%) with non-surgical retreatment. A statistically high number of patients (87.8%) tolerated the endodontic procedures without any sedation (P < 0.0001). Conclusion: Pediatric patients aged 6-12 compose around 7% of the population treated at the postgraduate Endodontics clinic, reflecting the high demand for endodontic treatment in a pediatric mixed dentition population.

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

BACKGROUND: The aim of this retrospective study was to compare the efficacy of concentrated growth factor (CGF) and platelet-rich fibrin (PRF) as scaffolds in regenerative endodontic therapy (RET). METHODS: Necrotic immature permanent teeth treated with regenerative endodontic therapy during January 2018 to August 2022 were divided into the CGF and PRF groups according to the scaffold. The CGF and PRF groups included 7 and 6 teeth, respectively. The efficacy of regenerative endodontic therapy was analyzed based on the clinical and radiological outcomes at three different follow up periods: T1 (3-6 months), T2 (6-12 months) and T3 (12-24 months). Statistical analysis was performed using the independent T test, Mann-Whitney test and Fisher's exact test at a significance level of 0.05. RESULTS: The success rate of each stage in both groups was 100%. Through quantitative comparison of radiographic outcomes, there was no statistically significant difference between the two groups in terms of root development and periapical lesion healing at each stage, except that the increase rate of radiographic root area in PRF group in the T3 stage was above one in CGF group with statistically significance. CONCLUSIONS: Both CGF and PRF had a similar clinical performance regarding resolution of clinical signs and symptoms, periapical lesion healing, and continued root development as scaffolds in RET. Further prospective studies with large samples for longer follow-up periods are needed.

Effects of an Nd:YAP laser used for root canal disinfection in pulp regenerative therapy: a pilot study.

This study aimed to compare the disinfection effects between a triple antibiotic paste and neodymium-doped yttrium aluminum perovskite (Nd:YAP) laser in pulp regenerative therapy and evaluate corresponding therapeutic effects based on apical radiographs and cone-beam computed tomography (CBCT). Sixty-six immature permanent teeth in 66 patients diagnosed with acute or chronic apical periodontitis were analyzed. All teeth were given pulp regenerative therapy. The patients were categorized into a control (triple antibiotic paste) and an experimental (Nd:YAP laser) group. Teeth in the experimental group were disinfected using an Nd:YAP laser, while those in the control group were disinfected using a triple antibiotic paste. Clinical and radiological examinations were performed every 3-6 months after treatment and followed up for 24 months. Statistical analysis was performed after clinical examination and showed that after one week of treatment, symptoms persisted in two teeth in the control group and two teeth in the experimental group. Two weeks later, the clinical symptoms disappeared in all teeth (p > 0.05). After 24 months of follow-up, the clinical symptoms recurred in two teeth in the control group and one tooth in the experimental group. On radiographic examination, 31 and 27 teeth showed continued root development, and three and two teeth showed no obvious root development in the control and experimental groups, respectively. The pulp sensibility test was positive in four teeth in both groups, with no significant difference between the two groups (p > 0.05). The results of this study suggest that endodontic irradiation with an Nd:YAP laser could be an effective alternative to triple antibiotic paste during disinfection of pulp regenerative therapy. Treatment outcomes were assessed using apical radiographs and CBCT, and no negative prognostic effects of the Nd:YAP laser on pulp regenerative therapy were found.

Enhancement of acellular biomineralization, dental pulp stem cell migration, and differentiation by hybrid fibrin gelatin scaffolds.

OBJECTIVE: The current in vitro study aims to evaluate cross-linked hydrogels with and without the addition of fibrin that could potentially be used in endodontic regeneration as a scaffold material. METHODS: Synthesis of gelatin/fibrin scaffold, and performing nanoscale characterization using cryo-electron microscopy, dynamic rheology, and XRF for structure property relations; plating dental pulp stem cells and determining mineralization, migration, and differentiation using rt-PCR, XRF, and Raman spectroscopy. RESULTS: Cryo electron imaging shows gelatin and fibrin, when gelled separately to form classical rectangular cross-linked networks, where the modulus scales inversely with the cube root of the mesh size. When gelled together, a network with a fundamentally different structure is formed, which has higher ductility and when placed as a scaffold in osteogenic media, produces twice the mineral content. Immunofluorescence, RT-PCR and Rahman Spectroscopy indicate that the hybrid gel enhances cell migration, induces odontogenic differentiation of dental pulp stem cells, and promotes formation of dentin. SIGNIFICANCE: The mechanical properties of the hybrid gel scaffold enhance in-migration of stem cells and subsequent differentiation, which are critical for regenerative procedures. Under acellular conditions, placement of the hybrid gel enhances biomineralization, which would strengthen the root if used as a scaffold for endodontic regeneration. Our in vitro findings are consistent with previous in vivo studies which show improved mineralization when bleeding is induced into the canal, given that fibrin is a primary component in blood clotting. Therefore, insertion of the hybrid gelatin-fibrin scaffold could enable more reproducible and consistent outcomes if used for regenerative endodontic treatment (RET).

Clinical Outcome and Comparison of Regenerative and Apexification Intervention in Young Immature Necrotic Teeth-A Systematic Review and Meta-Analysis.

This systematic review aimed to evaluate interventions individually and compare the clinical outcome of young, immature teeth treated with regenerative endodontic therapy (RET) and apexification procedure. The protocol was registered with PROSPERO (International Prospective Register of Systematic Reviews), bearing the registration number CRD42021230284. A bibliographic search in the biomedical databases was conducted in four databases-PubMed, CENTRAL, EMBASE and ProQuest-using searching keywords and was limited to studies published between January 2000 and April 2022 in English. The search was supplemented by manual searching, citation screening and scanning of all reference lists of selected paper. The study selection criteria were randomized clinical trial, prospective clinical studies and observational studies. The search found 32 eligible articles, which were included in the study. The quality assessment of the studies was performed using the Cochrane risk of bias tool for randomized control trials and non-randomized clinical studies. The meta-analysis was performed using Review Manager software (REVMAN, version 5). The results indicated that a clinicians' MTA apexification procedure was more successful compared to calcium hydroxide. In RET, apical closure and overall success rate is statistically same for both apical platelet concentrates (APCs) and blood clots (BC). Both interventions have similar survival rates; however, RET should be preferred in cases where the root development is severely deficient, there is insufficient dentine and the tooth's prognosis is hopeless even with an apexification procedure.

Regenerative Endodontic Procedures, Disinfectants and Outcomes: A Systematic Review.

AIMS: This systematic review aims to identify and synthesise available evidence to determine the clinical and radiographic outcomes of REP involving any disinfection irrigant together with a non-antibiotic intracanal medicament. METHODS: Experimental and observational studies evaluating the outcomes of REP in immature non-vital permanent teeth in 6-16 year olds, where the protocol used any type of disinfectant irrigant together with a non-antibiotic intracanal medicament (non-setting calcium hydroxide) were included. Data was narratively synthesised and presented in respect to the primary outcome (elimination of symptoms and infection) and secondary outcomes (increase in root length/width; positive response to vitality testing; patient-reported outcomes; adverse effects). MAIN FINDINGS: 1628 studies were identified, of which five met the eligibility criteria for inclusion in the review. Studies included one randomised control trial and four observational studies. All five studies showed an absence of clinical signs and symptoms for all teeth postoperatively with radiographic resolution or absence of pathology following the disinfection stages of the REP used. Choice of secondary outcomes were inconsistent but included further root development, coronal discolouration and root canal calcifications postoperatively. There was a high risk of bias in all five studies and subsequently the quality of the evidence base was judged to be low. PRINCIPLE CONCLUSIONS: REP using a non-antibiotic disinfectant approach appears capable of providing satisfactory outcomes for a non-vital immature permanent tooth. Further high-quality research is required before solid recommendations towards clinical practice guidelines for the disinfection portion of REP can be implemented.

12-year follow-up of regenerative endodontic treatment of immature permanent upper incisors with acute abscess

Abstract This case report discusses the endodontic treatment of a 7-year-old girl who suffered trauma (intrusion) to the immature upper central incisors secondary to a fall from a bicycle. Thirty days after the accident the patient was brought by her mother for clinical and radiographic assessment with a chief complaint of swelling and tenderness to percussion and palpation. Acute apical abscess associated with immature teeth were diagnosed. A decision was made to perform regenerative endodontic treatment. Access cavities were made and the root canals were disinfected by irrigation with 2.5% sodium hypochlorite. Final irrigation was performed with 17% EDTA. Due to pain and presence of secretions, 2% chlorhexidine gel was applied as an intracanal medicament. Seven days later, at the second visit, the root canals were once again disinfected and the canals of the right and left permanent upper central incisors were filled with double antibiotic paste (metronidazole/ciprofloxacin) and calcium hydroxide paste, respectively. Zinc oxide was mixed in both pastes. At the third visit, after 21 more days, the pastes were removed and the periapical areas were stimulated with a #80 K-file to encourage clot formation within the pulp cavities. A mineral trioxide aggregate (MTA) paste cervical plug was placed and the teeth were restored with glass ionomer cement. Radiographs and CBCT scans demonstrated complete root formations. The patient has been followed for 12 years, with evidence of clinical success throughout.

Resumo Este relato de caso discute o tratamento endodôntico de uma menina de 7 anos que sofreu trauma nos incisivos centrais superiores imaturos, após queda de bicicleta. Trinta dias após o acidente, a paciente foi levada pela mãe para avaliação clínica e radiográfica com queixa principal de inchaço e sensibilidade à percussão e palpação. Foram diagnosticados abscessos apicais agudos em ambos os dentes. Foi decidido por realizar o tratamento endodôntico regenerativo. Após acessos coronários, os canais radiculares foram submetidos à protocolos de antissepsia com auxílio de irrigação com hipoclorito de sódio a 2,5% e EDTA 17%. Devido à dor e presença de secreções, foi utilizada medicação intracanal com clorexidina gel 2% por 7 dias. Na segunda sessão, os canais radiculares foram novamente submetidos aos procedimentos de antissepsia e os canais dos incisivos centrais superiores permanentes direito e esquerdo foram preenchidos com pasta antibiótica dupla (Metronidazol / Ciprofloxacina) e pasta de hidróxido de cálcio, respectivamente. Em ambas as pastas foi adicionado o óxido de zinco. Na terceira sessão, após mais 21 dias, as pastas foram removidas e as regiões periapicais foram estimuladas com lima K nº 80 para incentivar a formação de coágulos sanguíneos no interior das cavidades pulpares. Tampões cervicais de MTA foram adaptados e os dentes restaurados com cimento de ionômero de vidro resinoso. Radiografias e tomografias computadorizadas demonstraram formações radiculares completas. A paciente é acompanhada há 12 anos, com evidências clínicas e radiográficas de sucesso.

Regenerative Endodontic Therapy with Platelet Rich Fibrin: Case Series.

Regenerative endodontic therapy (RET) provides a novel treatment modality for the immature teeth with pulp necrosis. The aim of this case series was to evaluate RET of immature permanent teeth using platelet rich fibrin (PRF) at 36-month follow-up periods. In the present case series, three immature maxillary incisors diagnosed with pulp necrosis and apical periodontitis were treated with RET. The root canals were irrigated with 1.5% sodium hypochlorite (NaOCl) and medicated with triple antibiotic paste(TAP). At the second visit, TAP was removed and root canals were conditioned with 17% EDTA. PRF was used as a scaffold. MTA was placed over PRF and the teeth were restored with composite resin. Periapical radiographs and cone beam computerized tomography(CBCT) were used to evaluate the healing. At the end of the 36-month follow-up periods, there was no response to pulp sensibility tests with cold and electric pulp tester, but all teeth showed decreased periapical lesions or evidence of healing.

Regenerative Endodontic Procedures Using Contemporary Endodontic Materials.

Calcium hydroxide apexification and Mineral Trioxide Aggregate (MTA) apexification are classical treatments for necrotic immature permanent teeth. The first tend to fail for lack of compliance given the high number of sessions needed; the second has technical difficulties such as material manipulation and overfilling. With both techniques, the root development is interrupted leaving the tooth with a fragile root structure, a poor crown-to-root ratio, periodontal breakdown, and high risk of fracture, compromising long-term prognosis of the tooth. New scientific literature has described a procedure that allows complete root development of these specific teeth. This regenerative endodontic procedure (REP) proposes the use of a combination of antimicrobials and irrigants, no canal walls instrumentation, induced apical bleeding to form a blood clot and a tight seal into the root canal to promote healing. MTA is the most used material to perform this seal, but updated guidelines advise the use of other bioactive endodontic cements that incorporate calcium and silicate in their compositions. They share most of their characteristics with MTA but claim to have fewer drawbacks with regards to manipulation and aesthetics. The purpose of the present article is to review pertinent literature and to describe the clinical procedures protocol with its variations, and their clinical application.

The efficacy of platelet-rich fibrin as a scaffold in regenerative endodontic treatment: a retrospective controlled cohort study.

BACKGROUND: Blood Clot (BC) or platelet concentrates have been used as scaffold in regenerative endodontic treatment (RET). The aim of this retrospective study was to compare the performance of platelet-rich fibrin (PRF) with BC in inducing root development and periapical lesion healing after tooth revascularization. METHODS: Five patients receiving RET using PRF as a scaffold were matched 1:1 to a previous cohort of 5 patients who underwent tooth revascularization by provoking periapical bleeding. Clinical signs and symptoms were examined at follow-ups. Periapical lesion healing and root development were monitored radiographically. The resolution of clinical signs and symptoms as well as periapical radiolucency was observed in all patients (100%). RESULTS: Root elongation, dentinal wall thickening and apex closure were found in most cases (80% in both groups). There was no significant difference between the groups in terms of clinical sign resolution, root development and periapical healing. CONCLUSIONS: Within the limits of this study, PRF achieved comparable outcomes to BC in terms of clinical sign and symptom resolution, periapical lesion healing and continued root development in RET.

[Effect of exogenous stem cells from apical papillae in the pulp revascularization treatment for the immature permanent tooth with periapical periodontitis].

Objective: To evaluate the effect of exogenous stem cells from apical papillae (SCAP) in the pulp revascularization treatment for the immature permanent tooth with periapical periodontitis in animal model. Methods: After the SCAP were isolated and cultured from the Beagle dogs, stem cell properties of these cells were characterized by analyzing their colony-forming ability, the expression of mesenchymal stem cell markers and the multidifferentiation characteristics including osteogenic, adipogenic, and chondrogenic potentials. Models of young permanent tooth with periapical periodontitis were established in dogs and the infection in each of the model tooth was eliminated by root canal irrigation and intracanal medication. After that, all of the model teeth were randomly divided into 4 groups: Group 1: normal developing teeth with no treatment applied;Group 2: teeth that periapical tissues were irritated to induce blood flowing into the root canals;Group 3: teeth that peripheral blood was delivered into the root canals;Group 4: teeth that SCAP were resuspended in peripheral blood and delivered into the root canals. In Group 2-4, firm coronal seal was performed after revascularization procedure and radiographs were taken periodically in order to observe the development of roots. After a 12-week-period, alveolar samples were collected and observed histologically. Results: The isolated SCAP showed clonogenic ability and multilineage differentiation ability including osteogenic, adipogenic and chondrogenic potentials. These cells also expressed the mesenchymal stem cell markers such as STRO-1 and CD146, while no cytokeratin was detected. The thickening of canal wall was observed radiographically 12 weeks after procedures of infection control and revascularization. Histologically, the newly formed tissues on the inner canal wall were found bone lacuna like structure in Group 2 and 3, and the new tissue formed in the Group 3 seemed easy to separate from the canal wall. The newly formed tissues in Group 4 were much thicker compare to those in the Group 2 and 3, and the dentine tubule like structure instead of bone lacuna was noticed although the orientation of these tubules were various. Conclusions: SCAP seem to play an important role in the tissue regeneration procedure when infection is well controlled in young permanent teeth with periapical periodontitis. It is difficult to achieve real tissue regeneration due to the lack of endogenous SCAP in apical area, therefore delivering adequate exogenous SCAP isolated and cultured in vitro could be a promising approach to overcome the challenge.

Luxação extrusiva de um incisivo central Permanente jovem: relato de caso clínico / Extrusive luxation of an immature permanent central incisor: clinical case report

Objetivo: O objetivo deste artigo é apresentar o relato de um caso clínico de luxação extrusiva de dente permanente com rizogênese incompleta, onde não foi necessária a realização de intervenção endodôntica. Relato de caso: Paciente de 6 anos de idade compareceu ao serviço de urgência da Policlínica Odontológica da Universidade do Estado do Amazonas (UEA) para atendimento após queda durante atividade de lazer, apresentando traumatismo direto na boca. Foi informado durante a consulta inicial que o incidente havia ocorrido há cerca de três dias, e que o atendimento imediato logo após o trauma foi realizado em um Serviço de Pronto Atendimento, porém, nenhum tipo de procedimento na cavidade oral foi realizado. Após exames clínico e radiográfico observou-se que o dente 21 apresentava deslocamento parcial para fora do alvéolo dentário no sentido axial, com alteração da oclusão, dor local à palpação e mobilidade dentária. Foi realizada profilaxia da área afetada, e anestesia do dente luxado e tecidos adjacentes. O reposicionamento do dente foi realizado em seguida, pressionando-o e tracionando-o de forma suave e contínua até a sua correta posição dentro do alvéolo. A área afetada foi limpa com gaze estéril embebida em soro fisiológico, e foi instalada uma contenção rígida confeccionada com fio ortodôntico e resina composta. Conclusão: O reposicionamento da maneira adequada do dente traumatizado dentro do alvéolo dentário, num período de tempo hábil, seguido de sua proservação, permitiram a manutenção da vitalidade do tecido pulpar, e consequentemente, o desenvolvimento do segmento radicular.

Objective: The objective of this article is to present a clinical case of extrusive luxation of an immature permanent tooth, with no endodontic management. Case report: A 6-year-old patient was provided to emergency treatment at the State University of Amazonas, as a result of a fall, with a direct trauma to the mouth. It was informed during the initial consultation that the incidente has occurred three days after. Emergency examination had been carried out by an Emergency Service; however, any type of procedure in the oral cavity was performed in ths occasion. After clinical and radiographic examinations, it was observed that tooth 21 presented partial displacement from the alveolar socket in the axial direction, with occlusion alteration, local pain to palpation and dental mobility. Cleaning of the affected area and anesthesia of the dislocated tooth and adjacent tissues were performed. Then, tooth repositioning was performed by pressing and tracing it smoothly and continuously until its correct position within the alveolar socket. The affected area was cleaned with sterile gauze soaked in saline solution, and a rigid containment made of orthodontic wire and composite resin was installed. Conclusion: A proper repositioning of the traumatized tooth within the alveolar socket, followed by its clinical followup, allowed the pulp tissue to remain vital, and consequently, the complete development of the root portion

Effect of exogenous stem cells from apical papillae in the pulp revascularization treatment for the immature permanent tooth with periapical periodontitis / 中华口腔医学杂志

Objective@#To evaluate the effect of exogenous stem cells from apical papillae (SCAP) in the pulp revascularization treatment for the immature permanent tooth with periapical periodontitis in animal model.@*Methods@#After the SCAP were isolated and cultured from the Beagle dogs, stem cell properties of these cells were characterized by analyzing their colony-forming ability, the expression of mesenchymal stem cell markers and the multidifferentiation characteristics including osteogenic, adipogenic, and chondrogenic potentials. Models of young permanent tooth with periapical periodontitis were established in dogs and the infection in each of the model tooth was eliminated by root canal irrigation and intracanal medication. After that, all of the model teeth were randomly divided into 4 groups: Group 1: normal developing teeth with no treatment applied;Group 2: teeth that periapical tissues were irritated to induce blood flowing into the root canals;Group 3: teeth that peripheral blood was delivered into the root canals;Group 4: teeth that SCAP were resuspended in peripheral blood and delivered into the root canals. In Group 2-4, firm coronal seal was performed after revascularization procedure and radiographs were taken periodically in order to observe the development of roots. After a 12-week-period, alveolar samples were collected and observed histologically.@*Results@#The isolated SCAP showed clonogenic ability and multilineage differentiation ability including osteogenic, adipogenic and chondrogenic potentials. These cells also expressed the mesenchymal stem cell markers such as STRO-1 and CD146, while no cytokeratin was detected. The thickening of canal wall was observed radiographically 12 weeks after procedures of infection control and revascularization. Histologically, the newly formed tissues on the inner canal wall were found bone lacuna like structure in Group 2 and 3, and the new tissue formed in the Group 3 seemed easy to separate from the canal wall. The newly formed tissues in Group 4 were much thicker compare to those in the Group 2 and 3, and the dentine tubule like structure instead of bone lacuna was noticed although the orientation of these tubules were various.@*Conclusions@#SCAP seem to play an important role in the tissue regeneration procedure when infection is well controlled in young permanent teeth with periapical periodontitis. It is difficult to achieve real tissue regeneration due to the lack of endogenous SCAP in apical area, therefore delivering adequate exogenous SCAP isolated and cultured in vitro could be a promising approach to overcome the challenge.

Ratio and Rate of Induced Root Growth in Necrotic Immature Teeth / 대한소아치과학회지

The purpose of this study was to analyze the ratio and rate of apical closure when inducing root growth of necrotic immature permanent teeth using alternative triple antibiotics. 24 permanent teeth in the treatment group and 27 premolars in the control group were retrospectively studied using periapical radiographs for more than 300 days after the first visit. The difference in the growth rate between the two groups was statistically compared using the Mann-Whitney test at a significance level of 0.05. There were no statistically significant differences between the two groups in the first month and during months 1 – 3, 3 – 6, and 6 – 12. After 12 months, the cumulative rate of decrease in the apical foramen width in the treatment group was 50.59% and that in the control group was 71.82%, which revealed a significant difference between the two groups. There were significant differences in the rates of decrease in the apical foramen width after 3, 6 months, and later period in the treatment group, respectively. The cumulative rate of increase in the root dentin area presented no statistically significant differences between the treatment group and control group during the entire period of examination.

Histologic Evaluation of Regenerative Endodontic Procedures with the Use of Chitosan Scaffolds in Immature Dog Teeth with Apical Periodontitis.

INTRODUCTION: The aim of this study was to evaluate histologically the newly formed tissues after regenerative endodontic procedures (REPs) in dogs using either a blood clot (BC) or 2 different formulations of a chitosan hydrogel as scaffolds. METHODS: Apical periodontitis was induced by inoculating immature teeth with oral plaque in 4 beagle dogs. Teeth (n = 96) were divided into 2 control (n = 20) and 4 test groups (n = 76) according to the treatment: apexification and REPs with BC, sodium hyaluronate:chitosan (HA:CS) scaffolds, or pectin:chitosan (P:CS) scaffolds. All root canals were disinfected with 2.5% sodium hypochlorite and a triple antibiotic paste intracanal medicament before evoked bleeding, clot formation, or scaffold placement. Thirteen weeks after treatment, the animals were sacrificed and the jaw blocks harvested for histologic processing, histomorphometric analysis, and statistical analysis. RESULTS: The lumens of the root canals were completely filled with mineral trioxide aggregate with evidence of a mineralized apical bridge between the root canal walls in 83% of the samples in the apexification group. Vital vascularized tissue was found in the REP groups; apical closure happened in 66.7% of these treatments, and root growth was detected more often as an increase in thickness (85.6%) than in length (45.6%). The greatest amount of mineralized tissue inside the canal was observed in the BC group, with statistical significance compared with the HA:CS and P:CS groups (P < .05). Further histologic evaluation revealed the presence of apical papilla. CONCLUSIONS: The addition of chitosan scaffolds to blood in regenerative procedures in dogs did not improve the formation of new mineralized tissues along the root canal walls or the histologic evidence of the regeneration of a pulp-dentin complex.