Clinical and Radiographic Outcomes in Immature Permanent Necrotic Evaginated Teeth Treated with Regenerative Endodontic Procedures

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL RELEVANCE

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

Current Management of Dens Evaginatus Teeth Based on Pulpal Diagnosis

INTRODUCTION

Dens evaginatus (DE) is a dental anomaly with a supernumerary tubercle projection that typically contains dentin and pulp tissue. However, the tubercle projection can fracture, exposing the dentin and potentially the dental pulp, which induces pulpal diseases. Managing DE should be primarily based on the clinical diagnosis of the pulp.

METHODS

The literature search in prevalence, prophylaxis, and management of dens evaginatus was performed in PubMed database as well as by manual search, in which the related contents were collected and descriptively analyzed.

RESULTS

Of the 264 searched literatures, 62 articles were included for this scoping review. The prophylactic management of the tubercle of DE teeth with a normal pulp should be performed as early as possible by the prep-and-fill technique or the reinforcement technique to preserve tooth vitality and continued root development, with the former reported to be superior compared with the latter. Furthermore, DE teeth with reversible pulpitis should be managed with the prep-and-fill technique. For DE teeth with irreversible pulpitis, vital pulp therapy, ie, partial or full/coronal pulpotomy, should be considered when the pulpal inflammation is limited to the coronal pulp to preserve the vitality of the radicular pulp that induces apexogenesis. A pulpectomy should be performed if the pulpal inflammation has progressed into the radicular pulp. For DE teeth with pulpal necrosis (or after pulpectomy) and immature roots, mineral trioxide aggregate apexification or regenerative endodontic procedures are the treatment options. For DE teeth with pulpal necrosis and complete root formation, nonsurgical root canal treatment is the treatment of choice. A flow chart of the decision-making for managing DE teeth based on pulpal diagnosis is proposed.

CONCLUSION

DE teeth should be properly managed, by prophylaxis or treatment, depending on pulpal diagnosis and related factors.

Artificial intelligence in diagnosing dens evaginatus on periapical radiography with limited data availability

This study aimed to develop an artificial intelligence (AI) model using deep learning techniques to diagnose dens evaginatus (DE) on periapical radiography (PA) and compare its performance with endodontist evaluations. In total, 402 PA images (138 DE and 264 normal cases) were used. A pre-trained ResNet model, which had the highest AUC of 0.878, was selected due to the small number of data. The PA images were handled in both the full (F model) and cropped (C model) models. There were no significant statistical differences between the C and F model in AI, while there were in endodontists (p = 0.753 and 0.04 in AUC, respectively). The AI model exhibited superior AUC in both the F and C models compared to endodontists. Cohen's kappa demonstrated a substantial level of agreement for the AI model (0.774 in the F model and 0.684 in C) and fair agreement for specialists. The AI's judgment was also based on the coronal pulp area on full PA, as shown by the class activation map. Therefore, these findings suggest that the AI model can improve diagnostic accuracy and support clinicians in diagnosing DE on PA, improving the long-term prognosis of the tooth.

Is Etiology a Key Factor for Regenerative Endodontic Treatment Outcomes?

INTRODUCTION

This study aimed to evaluate treatment outcomes of regenerative endodontic treatment (RET) in nonvital immature permanent teeth due to developmental malformation and trauma, and to analyze the influence of etiology on the prognosis.

METHODS

Fifty-five cases were included and divided into a malformation group (n=33) and a trauma group (n=22). Treatment outcomes were classified as healed, healing and failure. Root development was evaluated in terms of root morphology and the percentage changes in root length, root width and apical diameter during a follow-up period of 12 to 85 months (mean 30.8 months).

RESULTS

The mean age and the mean degree of root development in the trauma group were significantly younger than that in the malformation group. The success rate of RET was 93.9% (81.8% healed, 12.1% healing) in the malformation group and 90.9% (68.2% healed, 22.7% healing) in the trauma group, showing no statistically significant difference. The proportion of type I-III root morphology in the malformation group (97%, 32/33) was significantly higher than that in the trauma group (77.3%, 17/22) (P<0.05), whereas there was no significant difference in the percentage changes of root length, root width and apical diameter between the two groups. Six cases (6/55, 10.9%) showed no significant root development (type IV-V) (1 in the malformation group and 5 in the trauma group). Six cases (6/55, 10.9%) revealed intracanal calcification.

CONCLUSIONS

RET achieved reliable outcomes regarding the healing of apical periodontitis and continued root development. The etiology seems to influence the outcome of RET. Malformation cases presented with a better prognosis than trauma cases after RET.

Bioceramics in Endodontics: Updates and Future Perspectives

Bioceramics, with excellent bioactivity and biocompatibility, have been widely used in dentistry, particularly in endodontics. Mineral trioxide aggregate (MTA) is the most widely used bioceramic in endodontics. Recently, many new bioceramics have been developed, showing good potential for the treatment of endodontic diseases. This paper reviews the characteristics of bioceramics and their applications in various clinical endodontic situations, including root-end filling, root canal therapy, vital pulp therapy, apexification/regenerative endodontic treatment, perforation repair, and root defect repair. Relevant literature published from 1993 to 2023 was searched by keywords in PubMed and Web of Science. Current evidence supports the predictable outcome of MTA in the treatment of endodontic diseases. Although novel bioceramics such as Biodentine, EndoSequence, and calcium-enriched mixtures have shown promising clinical outcomes, more well-controlled clinical trials are still needed to provide high-level evidence for their application in endodontics. In addition, to better tackle the clinical challenges in endodontics, efforts are needed to improve the bioactivity of bioceramics, particularly to enhance their antimicrobial activity and mechanical properties and reduce their setting time and solubility.

Effect of Intracanal Scaffolds on the Success Outcomes of Regenerative Endodontic Therapy - A Systematic Review and Network Meta-analysis

INTRODUCTION

The scaffolds used in regenerative endodontic therapy (RET) provide structural support for cells so that they can adhere to the scaffolds and also are crucial for cellular proliferation and differentiation. The objective of this network meta-analysis was to compare effects of different intracanal scaffolds on success outcomes of RET.

METHODS

PubMed/Medline, EMBASE, Cochrane, CINAHL, Scopus, and Web of Science databases were searched. Studies evaluating and/or comparing clinical and/or radiographic success of RET using different scaffolds with a minimum of 12 months follow-up were included. The Cochrane Collaboration risk of bias (ROB) tool and appropriate tools from Joanna Briggs Institute were used for the assessment of ROB. A network meta-analysis was performed to compare the primary outcome (clinical success) and other success outcomes (root maturation, and pulpal sensibility) using different scaffolds.

RESULTS

Twenty-seven studies fulfilled the desired inclusion criteria of which 25 had a low ROB whereas 2 had a moderate ROB. Clinical success of RET using platelet-rich plasma (PRP), blood clot (BC), and platelet-rich fibrin (PRF) scaffolds ranged between 91.66%-100%, 84.61%-100%, and 77%-100% respectively. The different scaffolds did not show any statistically significant difference in clinical success (PRF vs BC [P = 1.000], PRP vs BC [P = 1.000], and PRF vs PRP [P = .999]), apical root closure (PRF vs BC [P = 1.000], PRP vs BC [P = .835], PRF vs PRP [P = .956]), and pulp sensibility (PRF vs BC [P = .980], PRP versus BC [P = .520], and PRF vs PRP [P = .990]).

CONCLUSION

The intracanal scaffolds used during RET did not result in significant differences in regard to clinical success, root maturation, and pulpal sensibility.

Modified pulpotomy procedure in immature permanent teeth with apical periodontitis: a randomised controlled trial

OBJECTIVES

The objective of this study was to evaluate the effectiveness of a modified pulpotomy (MP) procedure in immature permanent teeth with apical periodontitis (AP).

DESIGN

Randomised controlled trial.

SETTING

One public hospital in Shanghai, China PARTICIPANTS: A total of 33 teeth (31 patients) with a definitive diagnosis of AP with radiographic periapical radiolucency were recruited in this study. All the patients (teeth) completed the study accordingly.

METHODS AND INTERVENTION

Patients were randomly assigned to either MP or apexification treatment groups and were followed up for 12 months. Clinical symptoms and complications were recorded, and parallel periapical radiographic images were used to measure changes in root length and apical diameter. Wilcoxon's rank sum test and Fisher's exact test were used to compare the clinical and radiographic outcomes between MP and apexification, and analysed with analysis of variance.

MAIN OUTCOME MEASURE

The primary outcome was increase in root length at 12 months. The secondary outcomes included tooth survival, clinical success and decrease in apical diameter.

RESULTS

MP group showed a significant increase in root length (10.05%±2.14% vs 1.16%±0.79%, p<0.05) at 12 months and a decrease in apical diameter (48.88%±10.42% vs 15.90%±8.88%, p<0.05) as compared with the apexification group. The tooth survival rate was 100%, and 90.91% (30/33) of teeth were asymptomatic with apical healing in both treatment groups (p>0.05).

CONCLUSIONS

MP can be an option for treating immature permanent teeth with AP. MP showed better performance in terms of continued root maturation than apexification. MP and apexification achieved comparable outcomes with regard to the resolution of clinical symptoms and apical healing.

TRIAL REGISTRATION NUMBER

ChiCTR-INR-17012169.

Neural Regeneration in Regenerative Endodontic Treatment: An Overview and Current Trends

Pulpal and periapical diseases are the most common dental diseases. The traditional treatment is root canal therapy, which achieves satisfactory therapeutic outcomes-especially for mature permanent teeth. Apexification, pulpotomy, and pulp revascularization are common techniques used for immature permanent teeth to accelerate the development of the root. However, there are obstacles to achieving functional pulp regeneration. Recently, two methods have been proposed based on tissue engineering: stem cell transplantation, and cell homing. One of the goals of functional pulp regeneration is to achieve innervation. Nerves play a vital role in dentin formation, nutrition, sensation, and defense in the pulp. Successful neural regeneration faces tough challenges in both animal studies and clinical trials. Investigation of the regeneration and repair of the nerves in the pulp has become a serious undertaking. In this review, we summarize the current understanding of the key stem cells, signaling molecules, and biomaterials that could promote neural regeneration as part of pulp regeneration. We also discuss the challenges in preclinical or clinical neural regeneration applications to guide deep research in the future.

Tissue Characteristics in Endodontic Regeneration: A Systematic Review

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

Biomaterial scaffolds for clinical procedures in endodontic regeneration

Regenerative endodontic procedures have been rapidly evolving over the past two decades and are employed extensively in clinical endodontics. These procedures have been perceived as valuable adjuvants to conventional strategies in the treatment of necrotic immature permanent teeth that were deemed to have poor prognosis. As a component biological triad of tissue engineering (i.e., stem cells, growth factors and scaffolds), biomaterial scaffolds have demonstrated clinical potential as an armamentarium in regenerative endodontic procedures and achieved remarkable advancements. The aim of the present review is to provide a broad overview of biomaterials employed for scaffolding in regenerative endodontics. The favorable properties and limitations of biomaterials organized in naturally derived, host-derived and synthetic material categories were discussed. Preclinical and clinical studies published over the past five years on the performance of biomaterial scaffolds, as well as current challenges and future perspectives for the application of biomaterials for scaffolding and clinical evaluation of biomaterial scaffolds in regenerative endodontic procedures were addressed in depth.

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Overview of biomaterials for scaffolding in regenerative endodontics are presented.

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Findings of preclinical and clinical studies on the performance of biomaterial scaffolds are summarized.

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Challenges and future prospects in biomaterial scaffolds are discussed.

A critical analysis of clinical research methods to study regenerative endodontics

Regenerative endodontic treatment such as revitalization provides a treatment option for immature teeth with pulp necrosis. The main difference to the alternative procedure, the apical plug, is the induction of a blood clot inside the canal as a scaffold for healing and new tissue formation. Due to the biology-based and minimally-invasive nature of the treatment, revitalization has raised considerable interest in recent years. Whereas the procedure is fairly new and recommendations from endodontic societies have been in place only for a few years, the treatment protocol has evolved over the past two decades. Evidence has been created, not only from laboratory and animal work, but also from clinical studies including case reports, cohort studies and eventually prospective randomized controlled clinical trials, systematic reviews and meta-analyses. However, the research methods and clinical studies with subsequent reports oftentimes present with methodical limitations, which makes it difficult to objectively assess the value of this treatment modality. Several open questions remain, including the need for a more differentiated indication of revitalization after different traumatic injuries, the long-term prognosis of treated teeth and the true benefits for the patient. Therefore, this review aims to identify and reflect on such limitations, scrutinizing study design, diagnostic tools, procedural details and outcome parameters. A core outcome set is also proposed in this context, which can be considered in future clinical investigations. These considerations may lead to a more detailed and stringent planning and execution of future studies in order to create high-quality evidence for the treatment modality of revitalization and thus provide more robust data, create a larger body of knowledge for clinicians and further specify current recommendations.

Novel Approaches for the Treatment of Necrotic Immature Teeth Using Regenerative Endodontic Procedures: A Systematic Review and Meta-Analysis

The induction of a blood clot allowing apical revascularization with a subsequent apical closure was reported several decades ago. Recent research has been focused on examining different scaffolds for regenerative endodontic procedures (REPs). The aim of this study was to analyze the main outcomes in novel REP reported in the literature. The search was conducted using six databases. Only clinical trials aiming at the study of scaffolds for REP in the treatment of necrotic immature teeth were included. The risk of bias was assessed by the Risk of Bias 2 tool. Additionally, the quality of the included studies was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. A summary of individual studies and a meta-analysis were performed. Relative risks of data from clinical success and root length changes were used from the studies, and these were combined using a random-effects meta-analysis. The meta-analysis results reveal that the main outcomes showed no differences between the patients who received REP with scaffolds or only REP. Limitations include that the certainty of evidence was low and that there was significant heterogeneity in the scaffolds used in the included studies. The data suggest that the blood clot remains as the gold standard for REP.

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

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

Treatment outcomes of pulp revascularization in traumatized immature teeth using calcium hydroxide and 2% chlorhexidine gel as intracanal medication

OBJECTIVE

Pulp revascularization is an effective treatment for immature necrotic teeth. Calcium hydroxide has been used in pulp revascularization as an intracanal medication due to its antimicrobial action and the non-exhibition of crown discoloration and cytotoxicity for stem cells from the apical papilla. Our study aimed to investigate the clinical success and quantitative radiographic changes of root development in immature traumatized teeth using calcium hydroxide plus 2% chlorhexidine gel as intracanal medication.

METHODOLOGY

In this retrospective study, 16 patients were treated with a standardized pulp revascularization protocol. Calcium hydroxide and 2% chlorhexidine gel were manipulated in a 1:1 (v/v) ratio and inserted into root canals with Lentulo spirals (Dentsply Maillefer, Baillaigues, Switzerland). Patients were followed up for a period from 9 to 36 months for the evaluation of clinical and radiological data. Radiographic measurements of root length, root width, apical diameter, and MTA placement from the apex were quantified using software ImageJ. Wilcoxon test and t-test were used, according to nonparametric or parametric data, respectively, for changes over time in root length, root width, and apical diameter.

RESULTS

Fifteen teeth survived during the follow-up period (93.75%) and met the criteria for clinical success. Although the changes seem to be very small in many cases, significant increases in the average root length (14.28%, p<0.0001), root width (8.12%, p=0.0196), and decrease in apical diameter (48.37%, p=0.0007) were observed. MTA placement from the apex and age at the time of treatment was not significantly associated with the quantitative radiographic outcomes.

CONCLUSIONS

Pulp revascularization in traumatized immature teeth treated with calcium hydroxide plus 2% chlorhexidine gel as intracanal medication had high success and survival rates, showing periodontal healing and resolution of signs and symptoms. However, concerning the continued root development, the outcomes can still be considered unpredictable.

Effectiveness of the static-guided endodontic technique for accessing the root canal through MTA and its effect on fracture strength

OBJECTIVES

(1) To evaluate the effectiveness of the static-guided (SG) endodontics technique for accessing the root canal through the mineral trioxide aggregate (MTA) and (2) to evaluate the effect of this technique on the fracture strength of teeth.

MATERIALS AND METHODS

Thirty mandibular premolars were used in the present study. After standard coronal access cavity preparation, root canals were prepared up to size #80 to simulate an immature root apex. White MTA was placed approximately 3 mm below the cementoenamel junction (CEJ), as placed in regenerative endodontic procedures. After the MTA had set, the cavity was restored with a resin composite material. The teeth were randomly divided into two groups (n = 15). In the control group, the composite resin and MTA were removed without any guide. In the SG-access group, a cone beam computed tomography (CBCT) scan was performed, 3D-printed guides were designed and fabricated, and then the composite resin and MTA were removed with a guide. One inexperienced operator performed the removal of the composite resin and MTA in all groups. Pre- and post-operative periapical radiographs were taken. The mishaps and time to penetration to root canal were recorded. After that, the root canals were filled, and the access cavities were restored. The samples were subjected to a fracture strength test. Data were analyzed using Mann-Whitney U, independent samples of T test, and chi-square tests at 95% confidence level (P = 0.05).

RESULTS

There were significant differences between the control and SG-access groups in terms of mishaps and time to penetration to the root canal through the MTA barrier (P < 0.05). The SG-access group required the shorter time as compared with the control group. Mishaps did not occur in the SG-access group. The SG-access group exhibited the significantly preserved fracture resistance of the teeth as compared with the control group (P < 0.05). Non-restorable failure occurred more frequently in the control group than in the SG-access group.

CONCLUSIONS

Within the limitations of the present study, the SG endodontic technique yielded favorable results with respect to time, mishaps, and fracture strength.

CLINICAL RELEVANCE

The static-guided endodontics technique may provide advantages to the clinician for MTA removal.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Histologic Evaluation of Regenerated Tissues in the Pulp Spaces of Teeth with Mature Roots at the Time of the Regenerative Endodontic Procedures

INTRODUCTION

Recently, regenerative endodontic procedures (REPs) have been used to treat mature permanent teeth with apical periodontitis. Although animal studies with regard to histopathological findings after REPs exist, there is a paucity of studies on mature human teeth. As yet, the nature of tissues formed in the root canal of such teeth has not been established. This report presents histologic findings with regard to regenerative tissues in the pulp spaces exposed after dental trauma in human mature maxillary incisor teeth successfully treated with REPs.

METHODS

A 20-year-old girl was referred to our clinic for the treatment of her central incisors (#8 and #9). The incisors had apical periodontitis. REPs were performed on both maxillary central incisors. Three years 5 months after the initial treatment, the teeth had a horizontal crown fracture and needed a fiber post as well as root canal treatment. Mineral trioxide aggregate was carefully removed, and the tissue that had formed in the canal space was processed for routine histologic and immunohistochemical examination.

RESULTS

Histologic findings of the present case showed that the vital tissue formed in the canal space was fibrous connective tissue that contains bonelike tissue, vascular structures, and inflammation. These histologic findings obtained from mature teeth were similar to the findings of previous reports relating to immature teeth.

CONCLUSIONS

Based on the present case, the vital tissue formed in the canal space is fibrous connective tissue that contains bonelike tissue, vascular structures, and inflammation. These histologic findings with regard to mature teeth were similar to the findings of previous reports relating to immature teeth.

Regenerative Endodontic Procedures Posttrauma: Immunohistologic Analysis of a Retrospective Series of Failed Cases

INTRODUCTION

Regenerative endodontic procedures (REP) are a novel treatment modality to restore the function of necrotic pulp tissue via stimulation or transplantation of stem cells into the root canal. This study aimed to investigate the immunohistologic outcome of 3 extracted teeth because of sequelae of trauma and unsatisfactory REP outcomes.

METHODS

Three immature permanent maxillary central incisors of 3 female patients (6-9 years) were extracted 5.5-22 months after REP. Additionally, 1 sound permanent immature central maxillary incisor of 1 of the included patients was extracted for orthodontic reasons. The teeth were immunohistologically stained with Masson's trichrome, neurofilament (NF), pan cytokeratin, dentin sialophosphoprotein, and Gram+/-.

RESULTS

The REP-teeth presented intracanalar vascularized connective/mineralized reparative tissue (RT), which was less organized than the pulp tissue of the sound tooth. Moderate to considerable calcification was observed below the Portland cement used during REP. In 1 case, the RT was NF+; in the 2 other cases, the periodontal ligament and apical granuloma/papilla were NF+. All teeth were Gram+/- negative; nevertheless, inflammatory cells were present in 2 cases. The pan cytokeratin and dentin sialophosphoprotein stainings were not specific enough for 2 cases.

CONCLUSIONS

This immunohistologic study of failed REP cases resulted in bacteria-free intracanalar RT and biomaterial-induced calcification. Nevertheless, the presence of inflammatory cells revealed a persistent inflammation. Hence, the clinical and radiographic signs were decisive for tooth survival and multidisciplinary outcome determination.

Mineral trioxide aggregate and other bioactive endodontic cements: an updated overview - part II: other clinical applications and complications

Mineral trioxide aggregate (MTA) is a dental material used extensively for vital pulp therapies (VPT), protecting scaffolds during regenerative endodontic procedures, apical barriers in teeth with necrotic pulps and open apices, perforation repairs as well as root canal filling and root-end filling during surgical endodontics. A number of bioactive endodontic cements (BECs) have recently been introduced to the market. Most of these materials have calcium and silicate in their compositions; however, bioactivity is a common property of these cements. These materials include the following: BioAggregate, Biodentine, BioRoot RCS, calcium-enriched mixture cement, Endo-CPM, Endocem, EndoSequence, EndoBinder, EndoSeal MTA, iRoot, MicroMega MTA, MTA Bio, MTA Fillapex, MTA Plus, Neo MTA Plus, Ortho MTA, Quick-Set, Retro MTA, Tech Biosealer, and TheraCal LC. It has been claimed that these materials have properties similar to those of MTA but without the drawbacks. In Part I of this review, the available information on the chemical composition of the materials listed above was reviewed and their applications for VPT was discussed. In this article, the clinical applications of MTA and other BECs will be reviewed for apexification, regenerative endodontics, perforation repair, root canal filling, root-end filling, restorative procedures, periodontal defects and treatment of vertical and horizontal root fractures. In addition, the literature regarding the possible drawbacks of these materials following their clinical applications is reviewed. These drawbacks include their discolouration potential, systemic effects and retreatability following use as a root filling material. Based on selected keywords, all publications were searched regarding the use of MTA as well as BECs for the relevant clinical applications. Numerous publications were found regarding the use of BECs for various endodontic applications. The majority of these investigations compared BECs with MTA. Despite promising results for some materials, the number of publications using BECs for various clinical applications was limited. Furthermore, most studies had several methodological shortcomings and low levels of evidence.

Regenerative Endodontics

Regenerative endodontics has been defined as “biologically based procedure designed to replace damaged structures, including dentin and root structures, as well as cells of the pulp–dentin complex.” This is an exciting and rapidly evolving field of human endodontics for the treatment of immature permanent teeth with infected root canal systems. These procedures have shown to be able not only to resolve pain and apical periodontitis but continued root development, thus increasing the thickness and strength of the previously thin and fracture-prone roots. In the last decade, over 80 case reports, numerous animal studies, and series of regenerative endodontic cases have been published. However, even with multiple successful case reports, there are still some remaining questions regarding terminology, patient selection, and procedural details. Regenerative endodontics provides the hope of converting a nonvital tooth into vital one once again.