Treatment Outcomes of Apexification or Revascularization in Nonvital Immature Permanent Teeth: A Retrospective Study

Intraradicular reinforcement of traumatized immature anterior teeth after MTA apexification

This review article describes the methods and clinical recommendations for reinforcing traumatized anterior immature teeth with pulp necrosis treated with mineral trioxide aggregate (MTA) apexification. Traumatic injury can cause pulp necrosis and incomplete root formation in immature teeth. MTA apexification is the treatment of choice for necrotic immature teeth, particularly during the middle or late stages of root development. MTA apexification has a high success rate; however, failures due to cervical or root fractures occasionally occur. The risk of fracture is higher in immature teeth with thin root dentin, particularly those with external root resorption. Furthermore, the loading force from any parafunctional habit also increases fracture risk. Therefore, intra-radicular reinforcement may be necessary after MTA apexification. In vitro, intraradicular restoration with a resin composite/core build-up material or a prefabricated fiber post demonstrated better root reinforcement than root canal obturation materials (i.e., gutta-percha and sealer). However, the root-reinforcement effect of MTA orthograde filling in the entire root canal remains unclear. In vivo, the survival of fractured teeth with intraradicular restorations (resin composite/core build-up material or prefabricated fiber posts) is extremely high. Moreover, the survival of teeth with gutta-percha/sealer obturation or MTA orthograde filling and restoration with resin composite extending into the cervical third of the root canal approximately 1-2 mm below the cemento-enamel junction is acceptably high. Based on this evidence, the remaining tooth/root structure and loading force should be carefully examined when considering intra-radicular reinforcement of immature anterior teeth treated with MTA apexification.

Regenerative endodontic treatment and traumatic dental injuries

Pulp necrosis is the most common complication following dental trauma and is often associated with apical periodontitis. The management of these teeth is challenging in terms of large root canals, open apices, thin dentinal walls, and short roots. Over decades the conventional treatment for these teeth was calcium hydroxide apexification, a time-consuming procedure despite high success rates. Subsequently after the introduction of mineral trioxide aggregate and hydraulic calcium silicate materials single visit apical plug procedures became increasingly practiced with comparable success rates to the conventional apexification. The search continued afterward for a clinical procedure that may stimulate further root development and apical closure to avoid the long-term complication of root fracture after apexification. Regenerative procedures using stem cells derived from the apical papilla and blood clots as scaffolds were then introduced for the management of immature teeth, with variable protocols and success rates. This review will cover the evidence available and current position of regenerative endodontic procedures in traumatized immature teeth with apical periodontitis, in terms of clinical protocols, outcome, and potential prognostic factors.

Root Canal Dentin Microhardness after Contact with Antibiotic Medications: An In Vitro Study

Background: Antibiotic pastes used as intracanal medication in cases of revascularization therapy might cause negative effects on tooth properties, such as a reduction in dentin microhardness. This in vitro study investigated dentin microhardness in three different locations distancing from the canal lumen after 20 days of treatment with a tri-antibiotic paste (ciprofloxacin, metronidazole, and minocycline), and with a double-antibiotic paste (ciprofloxacin and metronidazole), with calcium hydroxide [Ca(OH)2] UltracalTM XS-treated dentin as comparison. Material and Methods: Human mandibular premolars (n = 48) had the root canals cleaned and shaped and were used to produce dentin slices. Dentin slices remained immersed in the medications for 20 days. The Knoop microhardness (KHN) test was performed before (baseline/Day-0) and after treatment (Day-20) with the medications. Indentations were made at 25 µm, 50 µm, and 100 µm distances from the root canal lumen. The KHN was compared intra-group using Wilcoxon's test. Independent groups were compared using Mann-Whitney's and Kruskal-Wallis' tests, at α = 5%. Results: The microhardness in all the tested groups was reduced at Day-20 in comparison with Day-0 (p < 0.001) (intra-group comparison/same distances). The Day-0 values were similar, and the Day-20 values were higher for the Ca(OH)2 group (p < 0.05) (comparison between groups/same distances). Conclusions: Calcium hydroxide for 20 days would be preferred rather than antibiotic pastes to minimize the expected reduction in dentin microhardness during regenerative procedures.

Pulp regeneration treatment using different bioactive materials in permanent teeth of pediatric subjects

Background and Objectives

The present systematic review aims to assess the success rate of the pulp regeneration treatment, according to the American Association of Endodontists (AAE) criteria, using different bioactive materials in permanent teeth of pediatric subjects (6-17 years of age).

Materials and Methods

The study protocol was registered on PROSPERO and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. The question formulation was accomplished using the PICO model, and an electronic search was carried out on Scopus, MEDLINE/PubMed, Web of Science, and Cochrane databases till April 1, 2023. A total of 30 studies were established to fulfill the inclusion criteria of this systematic review.

Results

A total of 273 teeth have been treated with pulp regeneration treatment. By comparing different biomaterials and the success criteria defined by the AAE, the material associated with a higher success rate was found to be the white mineral trioxide aggregate. However, the overall success rate of pulp regeneration treatment was reported for 248 out of 273 teeth (91.20%).

Conclusions

Data obtained support the potential that regenerative endodontics aids in continuing root development in permanent immature teeth. Further studies are needed for a more extensive evaluation of the use of different biomaterials and the success rate in regenerative endodontics.

Evaluation of Outcomes in Immature Teeth After Revitalization or Apexification Procedures: A Systematic Review and Meta-Analysis

There are two main treatment options for immature teeth with necrotic pulp and apical periodontitis. Apexification creates a mineralized tissue barrier, while revitalization aims to regenerate vital tissue in the canal space. There is no conclusive evidence to determine the most effective procedure regarding root length and dentin wall thickness. The objective of this systematic review was to compare the outcomes of revitalization and apexification procedures in immature non-vital teeth in terms of root length and dentin wall thickness. A literature search was conducted using the PubMed, ScienceDirect, Google Scholar, and Embase databases. Articles relevant to the study topic were gathered according to the selection criteria, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The included studies had to be published in English, conducted over a six-year period, and compared the outcomes of revitalization and apexification procedures in immature non-vital teeth. Data were collected using appropriate keywords from the eligible studies. Six articles were included for qualitative and quantitative analysis. The eligible studies showed a low risk of bias. In all revitalization cases, the root length increased significantly (mean difference (MD) (%) = 5.91; 95% confidence interval (CI) = 2.39-9.43; p = 0.0010; MD (mm) = 2.43; 95% CI = 2.05-2.80; p < 0.00001). The dentin wall thickness was statistically significant in most cases (MD (%) = 10.94; 95% CI = 7.01-14.88; p < 0.00001), MD (mm) = 0.16; 95% CI = 0.07-0.25; p = 0.0007). The systematic review and meta-analysis showed both procedures to be credible treatment options for necrotic immature teeth. Apexification had a positive impact, to some extent, on the development of root length. Revitalization yielded a significantly greater increase in root length and root dentin wall thickness and appeared to be superior in promoting root development.

Peptide KN-17-Loaded Supramolecular Hydrogel Induces the Regeneration of the Pulp-Dentin Complex

Regenerating the pulp-dentin complex remains a decisive factor during apexification for immature permanent teeth. Peptide KN-17, which was modified based on the structure of cecropin B, could effectively interfere with bacterial growth and induce the migration of human bone marrow stromal cells (hBMSCs). This study aimed to investigate the effect of KN-17 on the tissue regeneration. To our surprise, KN-17 can significantly stimulate angiogenesis in vitro and in vivo, which may provide a guarantee for apical closure. Herein, a novel peptide/KN-17 coassembled hydrogel is developed via a heating-cooling process. Npx-FFEY/KN-17 supramolecular hydrogel can induce vessel development, stimulate odontogenic differentiation of human dental pulp stem cells (hDPSCs), and exert an antibacterial effect on Enterococcus faecalis (E. faecalis). Furthermore, coronal pulp excised rat molars are supplied with KN-17 or KN-17-loaded hydrogel and transplanted subcutaneously in BALB/c-nu mice. After 4 weeks, the hydrogel Npx-FFEY/KN-17 stimulates the formation of multiple odontoblast-like cells and dentin-like structures. Our findings demonstrate that the KN-17-loaded hydrogel can promote the regeneration of the pulp-dentin complex for continued root development.

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.

The capability of regenerative endodontics to promote the complete root formation in immature permanent teeth with different initial pre-operative conditions

OBJECTIVES

To describe the potential possibility of complete root formation after regenerative endodontic procedures (REPs) in immature permanent teeth with different initial pre-operative conditions.

MATERIALS AND METHODS

Children who underwent REPs in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China, from January 2013 to December 2022 were enrolled. Whether the tooth achieved complete root formation was determined using post-operative periapical radiography. The potential possibility of complete root formation after REPs in immature permanent teeth with different initial conditions is discussed.

RESULTS

A total of 428 teeth from 401 patients were included, of which 258 (60.2%) achieved complete root formation. In cases that achieved complete root formation, the most serious type of trauma was avulsion, the teeth with the worst initial root development were less than one-third of the development (stages 6-7), and the longest duration of the presence of apical lesions in the tooth before the first visit was more than 180 days. There is a significant difference in the root formation of teeth with different initial developmental stages and diagnoses.

CONCLUSIONS

The active period of continued root formation was 5-21 months post-operatively. The higher the initial stage of root development and the shorter the duration of the presence of apical lesions in the tooth before the first visit, the greater the possibility of root formation. However, complete root formation may still be expected after REPs in severely injured immature permanent teeth and teeth with poor initial pre-operative root development conditions (less than stage 7) at the first visit. This is also true for teeth with long-term and large-scale apical lesions.

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.

Combination of metformin and double antibiotic paste for the regeneration of non-vital immature teeth: a preliminary randomized clinical study

BACKGROUND

The present study aimed to investigate whether incorporating metformin in double antibiotic paste (DAP) can promote the regeneration process of non-vital immature teeth.

METHODS

Out of 32 pediatric patients undergoing regenerative endodontic procedures (REPs), 6 cases with a follow-up period of less than 12 months or lack of documentation were excluded then the remaining 26 were analyzed. 15 cases received DAP, and 11 cases received a DAP + metformin as the intra-canal medicament, kept for an average of 23 days. During 18 months of follow-up, clinical and radiographic examinations were performed to evaluate the treatment outcomes based on the resolution of apical periodontitis, root development, and the occurrence of intracanal calcification. The chi-square test was used for the statistical analysis (P < 0.05).

RESULTS

All patients demonstrated resolution of apical periodontitis; however, complete apical closure was only seen in 50% of the patients. The rate of apical closure and root length was significantly higher in the DAP + metformin group (P = 0.047), although the two groups were not significantly different in terms of root width (P = 0.184). Canal obliteration was seen in 15% of cases, all of which were in the DAP group.

CONCLUSIONS

According to the present findings, metformin could promote root development in the regeneration process when incorporated in DAP.

TRIAL REGISTRATION

This clinical trial was registered on the Iranian Registry of Clinical Trials (IRCT20200120046197N1) on 26.2.2021.

Synergistic effect of ion-releasing fillers on the remineralization and mechanical properties of resin-dentin bonding interfaces

In modern restorative dentistry, adhesive resin materials are vital for achieving minimally invasive, esthetic, and tooth-preserving restorations. However, exposed collagen fibers are found in the hybrid layer of the resin-dentin bonding interface due to incomplete resin penetration. As a result, the hybrid layer is susceptible to attack by internal and external factors such as hydrolysis and enzymatic degradation, and the durability of dentin bonding remains limited. Therefore, efforts have been made to improve the stability of the resin-dentin interface and achieve long-term clinical success. New ion-releasing adhesive resin materials are synthesized by introducing remineralizing ions such as calcium and phosphorus, which continuously release mineral ions into the bonding interface in resin-bonded restorations to achieve dentin biomimetic remineralization and improve bond durability. As an adhesive resin material capable of biomimetic mineralization, maintaining excellent bond strength and restoring the mechanical properties of demineralized dentin is the key to its function. This paper reviews whether ion-releasing dental adhesive materials can maintain the mechanical properties of the resin-dentin bonding interface by supplementing the various active ingredients required for dentin remineralization from three aspects: phosphate, silicate, and bioactive glass.

Treatment of pulpal and apical disease: The European Society of Endodontology (ESE) S3-level clinical practice guideline

BACKGROUND

The ESE previously published quality guidelines for endodontic treatment in 2006; however, there have been significant changes since not only in clinical endodontics but also in consensus and guideline development processes. In the development of the inaugural S3-level clinical practice guidelines (CPG), a comprehensive systematic and methodologically robust guideline consultation process was followed in order to produce evidence-based recommendations for the management of patients presenting with pulpal and apical disease.

AIM

To develop an S3-level CPG for the treatment of pulpal and apical disease, focusing on diagnosis and the implementation of the treatment approaches required to manage patients presenting with pulpitis and apical periodontitis (AP) with the ultimate goal of preventing tooth loss.

METHODS

This S3-level CPG was developed by the ESE, with the assistance of independent methodological guidance provided by the Association of Scientific Medical Societies in Germany and utilizing the GRADE process. A robust, rigorous and transparent process included the analysis of relevant comparative research in 14 specifically commissioned systematic reviews, prior to evaluation of the quality and strength of evidence, the formulation of specific evidence and expert-based recommendations in a structured consensus process with leading endodontic experts and a broad base of external stakeholders.

RESULTS

The S3-level CPG for the treatment of pulpal and apical disease describes in a series of clinical recommendations the effectiveness of diagnosing pulpitis and AP, prior to investigating the effectiveness of endodontic treatments in managing those diseases. Therapeutic strategies include the effectiveness of deep caries management in cases with, and without, spontaneous pain and pulp exposure, vital versus nonvital teeth, the effectiveness of root canal instrumentation, irrigation, dressing, root canal filling materials and adjunct intracanal procedures in the management of AP. Prior to treatment planning, the critical importance of history and case evaluation, aseptic techniques, appropriate training and re-evaluations during and after treatment is stressed.

CONCLUSION

The first S3-level CPG in endodontics informs clinical practice, health systems, policymakers, other stakeholders and patients on the available and most effective treatments to manage patients with pulpitis and AP in order to preserve teeth over a patient's lifetime, according to the best comparative evidence currently available.

Endodontic Tissue Regeneration: A Review for Tissue Engineers and Dentists

The paradigm shift in the endodontic field from replacement toward regenerative therapies has witnessed the ever-growing research in tissue engineering and regenerative medicine targeting pulp-dentin complex in the past few years. Abundant literature on the subject that has been produced, however, is scattered over diverse areas of knowledge. Moreover, the terminology and concepts are not always consensual, reflecting the range of research fields addressing this subject, from endodontics to biology, genetics, and engineering, among others. This fact triggered some misinterpretations, mainly when the denominations of different approaches were used as synonyms. The evaluation of results is not precise, leading to biased conjectures. Therefore, this literature review aims to conceptualize the commonly used terminology, summarize the main research areas on pulp regeneration, identify future trends, and ultimately clarify whether we are really on the edge of a paradigm shift in contemporary endodontics toward pulp regeneration.

Effectiveness of revitalization in treating apical periodontitis: A systematic review and meta-analysis

BACKGROUND

Revitalization procedures primarily aim to eliminate clinical symptoms and heal periapical lesions.

OBJECTIVES

The objective of the study was to elucidate the effectiveness of revitalization in treating apical periodontitis in necrotic mature and immature permanent teeth based on the following PICO question: In patients with permanent immature or mature teeth and pulp necrosis with or without signs of apical periodontitis (P) what is the effectiveness of revitalization (I) in comparison with calcium hydroxide apexification, apical plug and root canal treatment (C) in terms of tooth survival, pain, tenderness, swelling, need for medication (analgesics and antibiotics), radiographic evidence of reduction of apical lesion size, radiographic evidence of normal periodontal ligament space, radiographic evidence of increased root thickness and length (not for mature teeth), tooth function (fracture and restoration longevity), need for further intervention, adverse effects (including exacerbation, restoration integrity, allergy and discolouration), oral health-related quality of life (OHRQoL), presence of sinus tract and response to sensibility testing (O). (T) = Defined as a minimum of 1 year and maximum of as long as possible for all outcome measures, except 'pain, tenderness, swelling, need for medication (analgesics)', which is a minimum of 7 days and maximum of 3 months and OHRQoL which is minimum of 6 months and a maximum of as long as possible.

METHODS

Three databases (PubMed, Embase and Cochrane Library) were searched for human, experimental and observational studies in English, complemented with hand search, until 31/10/2021. Studies recruiting teeth with pulp necrosis (with/without apical periodontitis), with minimum 10 teeth/arm at the end of the study and with a follow-up of at least 1 year, were included. Records without an abstract and a full text were excluded. The qualitative analysis of the included (non-) randomized controlled clinical trials was performed with the Revised Cochrane risk-of-bias tools (RoB 2 and ROBINS-I). Meta-analysis for survival and success (including a subgroup analysis for mature/immature permanent teeth) was performed using the Mantel-Haenszel method. The certainty of evidence was assessed using GRADE (Grades of Recommendation, Assessment, Development and Evaluation).

RESULTS

From the 365 identified records, five met the inclusion criteria. The 12 months survival rate was 100% for all (im)mature permanent teeth in all groups (3 studies). The success rate at 12 months was 100% for immature permanent teeth for I and C (1 study), however, reduced to 92% and 80% for mature teeth in I and C respectively (1 study, p > .05). The risk of bias for the most critical outcome (survival) was high for two studies and low for one. For the critical outcome success, all assessed studies were highly biased. Meta-analyses provided pooled relative risk with no statistically significant difference between I and C for both survival (RR = 1.00, 95%CI = 0.96-1.04, p = 1.00) and success (RR = 1.06; 95%CI = 0.83-1.35, p = .66). The evidence level for survival was kept 'low' and for success was downgraded to 'very low' due to inconsistency and imprecision.

DISCUSSION

The survival and success rates were favourable in all included studies and for all groups; however, these outcomes are not reliable due to the low certainty level. Clinically, the most reported adverse event was tooth discolouration, hence the application of bismuth oxide containing calcium silicate cements should be avoided in revitalization. Radiographically, caution is needed when assessing periapical bone healing and further root development with periapical radiographs, due to multifactorial inaccuracies of this imaging technique. Methodological and assessment concerns need to be addressed in future clinical trials. Long-term results are necessary for studies reporting revitalization of mature permanent teeth, as they seem to be experimental so far.

CONCLUSIONS

No robust evidence was discovered to support that revitalization is effective to treat apical periodontitis in (im)mature permanent teeth. The success and survival rates of revitalized and fully pulpectomized (im)mature permanent teeth did not differ significantly.

REGISTRATION

Prospero: CRD42021262466.

Evaluation of concentrated growth factor and blood clot as scaffolds in regenerative endodontic procedures: A retrospective study

The study aims to investigate and compare the success rate of concentrated growth factor (CGF) and blood clot (BC) as scaffolds in regenerative endodontic procedures (REPs). Immature permanent necrotic teeth treated by REPs with at least a 6-month follow-up were included. These teeth were divided into the CGF (53 teeth) and BC (68 teeth) groups. Treatment outcomes were assessed using a combined clinical and radiographic scoring system. The total success rate was 91.74% over a mean follow-up period of 23.15 months. There was no significant difference between the CGF group (86.79%) and BC group (95.59%). The success rate of traumatic teeth (84.31%) was significantly lower than that of teeth with developmental dental anomalies (98.39%) (p < 0.05). CGF may be a suitable alternative scaffold in REPs when adequate bleeding cannot be achieved. Moreover, compared to developmental dental anomalies, traumatic teeth treated by REPs may be more vulnerable to failure.

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.

Gelatin methacryloyl hydrogel as an injectable scaffold with multi-therapeutic effects to promote antimicrobial disinfection and angiogenesis for regenerative endodontics

Regenerative endodontics represents a paradigm shift in dental pulp therapy for necrotic young permanent teeth. However, there are still challenges associated with attaining maximum root canal disinfection while supporting angiogenesis and preserving resident stem cells viability and differentiation capacity. Here, we developed a hydrogel system by incorporating antibiotic-eluting fiber-based microparticles in gelatin methacryloyl (GelMA) hydrogel to gather antimicrobial and angiogenic properties while prompting minimum cell toxicity. Minocycline (MINO) or clindamycin (CLIN) was introduced into a polymer solution and electrospun into fibers, which were further cryomilled to attain MINO- or CLIN-eluting fibrous microparticles. To obtain hydrogels with multi-therapeutic effects, MINO- or CLIN-eluting microparticles were suspended in GelMA at distinct concentrations. The engineered hydrogels demonstrated antibiotic-dependent swelling and degradability while inhibiting bacterial growth with minimum toxicity in dental-derived stem cells. Notably, compared to MINO, CLIN hydrogels enhanced the formation of capillary-like networks of endothelial cells in vitro and the presence of widespread vascularization with functioning blood vessels in vivo. Our data shed new light onto the clinical potential of antibiotic-eluting gelatin methacryloyl hydrogel as an injectable scaffold with multi-therapeutic effects to promote antimicrobial disinfection and angiogenesis for regenerative endodontics.

Effects of EDTA and saline as the final irrigation in regenerative endodontic procedures on the migration, proliferation, and differentiation of human stem cells from the apical papilla

OBJECTIVES

To evaluate the effect of EDTA and saline as the final irrigation in regenerative endodontic procedures (REPS) on the attachment, proliferation, migration, and differentiation of stem cells from the apical papilla (SCAPs).

MATERIALS AND METHODS

Dentin specimens from 140 human third molars were irrigated with various protocols-group 1: normal sterile saline (NSS), group 2: EDTA, group 3: EDTA then 5 mL NSS, or group 4: EDTA then 20 mL NSS. The specimens were used in cell assays. For cell proliferation, SCAPs were seeded on dentin, and the cell viability on days 1, 3, and 7 was determined using an MTT assay. At day 3, the attached cells' morphology was observed using SEM, and cell migration was investigated using a transwell migration assay. The ALP activity and odonto/osteogenic differentiation gene expression were evaluated at days 7, 14, and 21 using an ALP activity assay and RT-qPCR.

RESULTS

On days 3 and 7, group 4 demonstrated more viable cells than group 1 (p < 0.01). The amount of migrated cells in groups 2, 3, and 4 was greater compared with group 1 (p < 0.05). Moreover, SCAP differentiation was similar between groups.

CONCLUSIONS

Irrigating dentin with EDTA alone or with EDTA then NSS promoted SCAP migration. However, a final irrigation with 20 mL NSS after EDTA promoted SCAP proliferation without affecting their differentiation.

CLINICAL RELEVANCE

When using a blood clot as a scaffold, a final flushing with 20 mL NSS after EDTA could be beneficial for clinical REP protocols.

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.

Assessment of bone quality of apical periodontitis treated with MTA plug and regenerative endodontic techniques

Fractal analysis (FA) is a quantitative, objective and non-invasive method that facilitates the characterisation of the tissue architecture. This study aims to compare the periapical healing at 1-year follow-up by evaluating newly generated trabecular bone with FA after Mineral trioxide aggregate (MTA) plug and regenerative endodontic treatment (RET). A total of 55 asymptomatic teeth with a single-canal, open apex and periapical lesion, treated with MTA plug or RET, were evaluated retrospectively. After considering the inclusion/exclusion criteria, FA was conducted on 30 periapical images using the box-counting method. In both groups, a significant decrease was observed in the periapical lesion size at 1-year follow-up (p < 0.01). However, there was no significant difference between the MTA plug and RET (p > 0.01). Significantly higher fractal dimension values were detected at 1-year follow-up in both MTA plug and RET cases (p < 0.01). However, the difference was not significant between the groups (p > 0.01). Both procedures seem to improve periapical healing with a new resistant bone of similar density and complexity.

Expert consensus on regenerative endodontic procedures

Regenerative endodontic procedures (REPs) is a biologic-based treatment modality for immature permanent teeth diagnosed with pulp necrosis. The ultimate objective of REPs is to regenerate the pulp-dentin complex, extend the tooth longevity and restore the normal function. Scientific evidence has demonstrated the efficacy of REPs in promotion of root development through case reports, case series, cohort studies, and randomized controlled studies. However, variations in clinical protocols for REPs exist due to the empirical nature of the original protocols and rapid advancements in the research field of regenerative endodontics. The heterogeneity in protocols may cause confusion among dental practitioners, thus guidelines and considerations of REPs should be explicated. This expert consensus mainly discusses the biological foundation, the available clinical protocols and current status of REPs in treating immature teeth with pulp necrosis, as well as the main complications of this treatment, aiming at refining the clinical management of REPs in accordance with the progress of basic researches and clinical studies, suggesting REPs may become a more consistently evidence-based option in dental treatment.

An Updated Review on Properties and Indications of Calcium Silicate-Based Cements in Endodontic Therapy

Regarding the common use of calcium silicate cements (CSCs) in root canal therapy, their position in the context of past and present dentistry agents can provide a better understanding of these materials for their further improvement. In this context, the present review article addresses a wide range of recent investigations in the field of CSC-based products and describes details of their composition, properties, and clinical applications. The need for maintaining or reconstructing tooth structure has increased in contemporary endodontic treatment approaches. This research thus discusses the attempts to create comprehensive data collection regarding calcium ion release, bond strength, alkalinizing activity and bioactivity, and the ability to stimulate the formation of hydroxyapatite as a bioactive feature of CSCs. Sealing ability is also highlighted as a predictor for apical and coronal microleakage which is crucial for the long-term prognosis of root canal treatment integrity. Other claimed properties such as radiopacity, porosity, and solubility are also investigated. Extended setting time is also mentioned as a well-known drawback of CSCs. Then, clinical applications of CSCs in vital pulp therapies such as pulpotomy, apexification, and direct pulp capping are reviewed. CSCs have shown their benefits in root perforation treatments and also as root canal sealers and end-filling materials. Nowadays, conventional endodontic treatments are replaced by regenerative therapies to save more dynamic and reliable hard and soft tissues. CSCs play a crucial role in this modern approach. This review article is an attempt to summarize the latest studies on the clinical properties of CSCs to shed light on the future generation of treatments.

Trends of calcium silicate biomaterials in medical research and applications: A bibliometric analysis from 1990 to 2020

Background: Calcium silicate biomaterials (CSB) have witnessed rapid development in the past 30 years. This study aimed to accomplish a comprehensive bibliometric analysis of the published research literature on CSB for biomedical applications and explore the research hotspot and current status.

Methods: Articles related to CSB published in the last three decades (1990–2020) were retrieved from Web of Science Core Collection. The R bibliometrix package and VOSviewer were used to construct publication outputs and collaborative networking among authors, their institutes, countries, journals’ matrices and keywords plus.

Results: A total of 872 publications fulfilling the search criteria were included. CSB is mainly reported for bone tissues and dental applications. Among researchers, Chang J from Chinese Academy of Sciences and Gandolfi MG from the University of Bologna are the most productive author in these two fields, respectively. China was the leading contributor to the research on CSB in the medical field. A total of 130 keywords appeared more ten or more times were identified. The term “mineral trioxide aggregate” ranked first with 268 occurrences. The co-occurrence analysis identified three major clusters: CSB in dentistry, bone tissue and vitro bioactivity.

Conclusion: Calcium silicate biomaterials have a promising scope for various biomedical applications ranging from regeneration of hard tissues (bone and teeth) to skin, tumor, cardiac muscle and other soft tissues. This study may help researchers further understand the frontiers of the field.

Antibacterial efficiency of adjuvant photodynamic therapy and high-power diode laser in the treatment of young permanent teeth with chronic periapical periodontitis. A prospective clinical study

BACKGROUND

The study aimed at determining antibacterial efficiency of adjuvant photodynamic therapy (PDT) and high-power diode laser (DL) in the treatment of chronic periapical periodontitis (CPP) in young permanent teeth.

METHODS

Forty-four young permanent teeth with CPP were randomly divided into three groups (PDT, DL and control). Each tooth underwent standard chemo-mechanical treatment, while within tested groups was additionally treated by PDT or DL. Bacterial identification and quantification were provided by MALDI-TOF spectrometry and plate counting assay, performed after accessing the canal, following chemo-mechanical preparation, and after PDT or DL procedure where applicable.

RESULTS

Thirty-nine young permanent teeth with CCP (patients age 9.77 ± 1.43) completed the study. Before the treatments, 202 isolates belonging to 13 genera/species, including Streptococcus (36), Actinomyces (34), Peptostreptococcus micros (27), Veillonella (25) and Enterococcus faecalis (22), were recovered. Chemo-mechanical treatment reduced CFU count in the all three groups (p < 0.001), but complete eradication was not observed for any of isolated species. Adjuvant PDT and DL completely eradicated isolates of 8 and 6 bacterial genera/species, resulting in complete bacterial elimination from 53.8% and 30.8% of root canals, respectively. In the rest canals, total Δlog CFUs were 4.71 and 4.58.

CONCLUSION

The results indicated that both PDT and DL could be performed as adjuvants to standard endodontic treatment of the young permanent teeth with CPP.

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.

Failure of regenerative endodontic procedures: case analysis and subsequent treatment options

INTRODUCTION

Regenerative endodontic procedures (REPs) are considered effective treatments for immature necrotic permanent teeth, with favorable outcomes. However, failed cases require subsequent treatment. This study aimed to review and analyze failed cases after REPs and suggest a treatment algorithm to aid clinical decision making.

METHODS

A total of 111 REP cases were selected that conducted between 2015-2020. Clinical outcomes were assessed based on clinical and radiographic evaluations. The criteria for failure included persistence of clinical signs or symptoms and/or periapical radiolucency showing persistent apical periodontitis. Cases requiring any treatment intervention, including extraction, were also considered failures.

RESULTS

Sixteen cases were included as failures. The etiology of pulpal disease was stratified into dental trauma (56%), dens evaginatus (25%), and dental caries (12.5%), with the remaining one case having an undocumented cause. The primary reasons for treatment failure were persistent infection (81.3%) and root resorption (18.7%). The identification time of failure varied, with six cases (37.5%) detected in less than six months and ten cases (62.5%) later than six months after REPs. Sixteen failed cases received five different interventions: second REPs, apexification, conventional root canal treatment, surgical approach, and extraction.

CONCLUSION

Interventions for failed REPs are challenging. Consideration of the treatability of the tooth, accessibility to the canal, and the presence of an apical seat might be key factors in clinical decision making to obtain a successful outcome.

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.

Physicochemical and biological properties of four calcium silicate-based endodontic cements

Background/purpose

Materials and methods

Results

Conclusion

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.

Intracanal calcification following regenerative endodontic treatment: a systematic review and meta-analysis

OBJECTIVES

Calcification is a common finding in endodontic cases after regenerative endodontic therapy (RET). We aimed to identify the prevalence of intracanal calcification after RET and to compare intracanal calcification outcomes in RET using either calcium hydroxide [Ca(OH)₂] or antibiotics.

MATERIALS AND METHODS

We searched PubMed, Web of Science, ProQuest Dissertations & Theses, and Scopus databases for clinical, cross-sectional, case-control, and cohort RET studies published until May 2020 in the English language and reporting a calcified case after RET. The Cochrane risk-of-bias tool for randomized trials and Risk of Bias In Non-randomized Studies of Interventions were used for bias assessment. Meta-analyses were performed, overall and separately, for intracanal medicaments using a random-effects model with weighted inverse variance methods. Subgroup analysis was performed according to the calcification type.

RESULTS

Eight studies were included. The overall prevalence of intracanal calcification after RET was 30.7% (95% confidence interval [CI]: 0.15-0.45,[Formula: see text]=92.6%), 46.5% with Ca(OH)₂ vs. 25.8% with antibiotic-based intracanal medicaments. Subgroup analyses for complete calcification outcome showed a higher prevalence of complete calcification in the Ca(OH)₂ group (46.5%, 95% CI: 0.17-0.68,[Formula: see text]%) than in the antibiotic group (10%, 95% CI: - 0.04-0.43,[Formula: see text]%).

CONCLUSIONS

Based on the studies included, available evidence shows a statistically significant association between complete calcification and Ca(OH)₂ paste as an intracanal medicament. Other contributing factors, such as blood clot formation and follow-up time, might also play an essential role in forming intracanal calcification.

CLINICAL RELEVANCE

This study highlights the significant association between complete calcification and Ca(OH)₂ paste.

Continued root development of immature permanent teeth after regenerative endodontics with or without a collagen membrane: A randomized, controlled clinical trial

BACKGROUND

Recent studies evaluated the efficacy of a collagen membrane (Bio-Gide) to promote root development in regenerative endodontics (REPs). However, the influence of etiology and tooth type on the results was not assessed.

AIMS

To evaluate the quantitative and qualitative effect of a collagen membrane (Bio-Gide), with and without the effect of etiology and tooth type, in promoting root development in immature teeth after REPs.

DESIGN

Eighty nonvital immature teeth were divided randomly into two groups (40 teeth in each group). REPs were performed with (experimental group) and without (control group) a collagen membrane. All teeth were subjected to regular clinical and radiographical follow-up.

RESULTS

Seventy-six teeth were included in the final analyses. The average follow-up periods were 33.1 ± 21.8 months for the control group and 28.1± 18.6 months for the experimental group. Quantitative analysis of root development in the experimental group showed a greater increase in dentin wall thickness in the middle one-third of the root compared to the control group, with or without the effect of etiology and tooth type. Six types of root development were observed. There was no significant difference in the type of tooth development between the two groups.

CONCLUSION

The use of a collagen membrane could promote an increase in dentin wall thickness in the middle one-third of the root, and it had no significant effect in terms of the type of subsequent root development.

Pulpotomy for treatment of complicated crown fractures in permanent teeth: A systematic review

Background

Consensus on the treatment of choice for complicated crown fractures of teeth is limited. Recent guidance recommends vital‐pulp‐therapy; however, the preferred type is not specified. Higher success rates for pulpotomy compared to pulp‐capping have been documented, which suggests pulpotomy may be a preferable option for complicated crown‐fractures.

Objectives

The purpose of this systematic review was to determine the success rate of pulpotomy (partial and complete) on teeth that suffered complicated crown fractures. Participants: patients who have suffered a complicated crown fracture to an anterior permanent tooth. Intervention: pulpotomy (partial or complete). Comparator: pulp‐capping or root canal treatment. Outcome: combined clinical and radiographic success at or after 12 months.

Methods

A systematic literature using key search terms was conducted using PubMed, Web of Science and Cochrane‐Central‐Register‐of‐Controlled‐Trials (CENTRAL) as well as a grey literature search from inception to May 2021 and without language restricted to English. Strict inclusion criteria were applied. A standardized tool with defined criteria to assess the risk of bias in each study was used. For non‐randomized comparative trials, the Robins‐I tool was used while the Newcastle‐Ottawa scale was used for non‐comparative non‐randomized studies.

Results

Seven retrospective clinical studies were included. The studies reported high success rates for pulpotomy with overall success ranges for partial or complete pulpotomy ranging from 75% to 96%. One study compared the success rates of pulpotomy to an alternative treatment option pulp capping (90.9% vs. 67%, respectively). Due to the lack of homogeneity in the included studies, a meta‐analysis was not possible.

Discussion

This review highlights the limited evidence based for the current guidance on treatment of complicated crown fractures. The findings of the review indicate high success rates for pulpotomy; however, there is a moderate risk of bias and small sample sizes in the included studies with the result that the overall results should be interpreted with caution.

Conclusion

Within the limitations of this review, the benefits and high success rates reported for partial pulpotomy suggest this procedure, rather than pulp‐capping, should be considered as the treatment of choice for both immature and mature teeth that have suffered complicated crown‐fractures.

Radiographic differences observed following apexification vs revascularization in necrotic immature molars and incisors: a follow-up study of 18 teeth

PURPOSE

To evaluate the effectiveness of apexification versus revascularization in the treatment of necrotic immature teeth and determine which strategy affords the greatest radiological success rate.

METHODS

An analysis was made of 18 teeth subjected to mineral trioxide aggregate (MTA) apical plugging and regenerative endodontic treatment, assessing healing of the apical lesions and the changes in root dimensions.

RESULTS

Significantly greater root growth was observed with revascularization in terms of the percentage change in length (12.75% at 6 months) and dentin thickness (34.57% at 6 months) (p < 0.05). There were no significant differences between the two treatments in terms of the apical healing scores after 6 months of follow-up (p > 0.05).

CONCLUSION

Apexification with an MTA apical plug and pulp regeneration are reliable treatments for non-vital immature teeth. The radiographic outcomes are comparable between the immature teeth subjected to MTA apexification versus those subjected to revascularization. The results of the present study indicate a greater increase in root length and width with regenerative endodontic treatment.

"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.

Patient centered outcomes among a cohort receiving regenerative endodontic procedures or apexification treatments

INTRODUCTION

This multi-centered cohort study evaluated factors associated with patient-centered outcomes of immature permanent teeth that received regenerative endodontic procedures (REPs) or apexification treatment (APEX).

METHODS

A record review identified teeth treated with REPs or APEX between September 2005-December 2014. Data regarding treatment and patient-centered outcomes were extracted from records with a 3-month minimum recall. When possible, participants presented for an in-person prospective research visit. Patient-centered success was defined as an asymptomatic, functional tooth, not requiring further endodontic or surgical intervention following completion of the original treatment during the study observation. Risk ratios and adjusted and unadjusted Cox proportional hazard ratios were calculated.

RESULTS

The analytic cohort of 187 individuals included 211 teeth (93 REPs; 118 APEX) with an average follow-up of 32 months. Most cases were successful (81% REPs; 92% APEX) and survived the observation period (96% REPs; 97% APEX). The success rate of REPs was lower than APEX and decreased more rapidly over time. Cox regression analysis demonstrated that when controlling for other variables, the association between treatment type and outcome is not significant. Preoperative infection, teeth with more immature roots, and REPs treatment are potentially important predictors. Among teeth receiving REPs, a lower failure rate was observed for teeth that received multi-antibiotic paste (3/43) compared to calcium hydroxide (11/45).

CONCLUSIONS

Teeth receiving REPs required clinical intervention earlier than teeth that received APEX treatment, although preoperative abscess and more immature root also affected this outcome. Using multi-antibiotic paste versus calcium hydroxide in REPs may improve success.

Effect of different coronal restorations on the fracture resistance of teeth with simulated regenerative endodontic treatment: An in vitro study

This study investigated the effect of different coronal restorations on the fracture resistance (FR) of immature teeth with simulated regenerative endodontic treatment. A total of 120 lower premolars were divided into eight groups. Except for negative control, the root canals were instrumented with rotary files and Peeso reamers. Fifteen instrumented teeth were acted as positive control (unrestorated). In the remaining 90 teeth, regenerative endodontic treatment procedures were performed. Ninety teeth were randomly divided into 6 groups according to coronal restoration type; Filtek Z550, Filtek Bulk fill Restorative (FBR), SDR+Filtek Z550, EverX+Filtek Z550, Ribbond+FBR and Ribbond+SDR+Filtek Z550. After thermal ageing, the restorated teeth were subjected to vertical loading force. FR values was obtained as follows: Negative control > Ribbond+FBR = Ribbond+SDR+Filtek Z550 > Filtek Z550 = FBR =SDR+Filtek Z550 = EverX+Filtek Z550 > Positive control, (P < 0.05). The use of Ribbond in combination with composite resin enhanced the FR of teeth.

Direct effect of transforming growth factor-beta 1 (TGF-β1) on human apical papilla cell proliferation and mineralisation

Firstly, this study investigated the direct effect of Transforming Growth Factor-beta 1 at 10, 5, 2.5 and 1.25 ng mL^-1 on human apical papilla cell proliferation and mineralisation. Cell proliferation was examined at 0, 2, 4, 6, 24, 48, 72, 96 and 120 h using Alamar Blue^TM assay. Cell mineralisation was examined at day 21 with a quantitative Alizarin Red S staining. Secondly, the study aimed to estimate the amount of Transforming Growth Factor-beta 1 (TGF-β1) released from the dentin after root canal irrigation. The solution collected from a root canal after rinsing with various protocols (normal saline solution, ethylenediaminetetraacetic acid or chlorhexidine) was analysed with an enzyme-linked immunosorbent assay. Data were statistically analysed using a one-way analysis of variance. The results, from the first part, revealed cell proliferation reduction in all experimental groups presented with TGF-β1. The higher concentration generated more deteriorating effects. Cell mineralisation was highest in a group with TGF-β1 at 1.25 ng mL^-1 (P < 0.05). For the growth factor released from dentin, the highest amount was detected only when ethylenediaminetetraacetic acid was associated with the irrigation (P < 0.05). In summary, the direct effects of TGF-β1 on cell proliferation and differentiation were diverse, depending on concentration. The release of TGF-β1 from root dentin can be achieved after rinsing with ethylenediaminetetraacetic acid.

Management of Inflammatory Root Resorption of Maxillary Central Incisors following Traumatic Avulsion

Background

Avulsion is among the most severe types of dental trauma, which often occurs at young ages and can compromise the long-term prognosis of the traumatized tooth. Case Report. Herein, we report replantation of two avulsed teeth. Our patient was an 11-year-old boy with two avulsed maxillary central incisors due to a bicycle fall 2 months earlier. The patient was referred to us after rigid splinting of his teeth by a surgeon. Long-term calcium hydroxide (CH) therapy was performed for the patient, and after healing of periodontal ligament (PDL), apexification was performed for both teeth followed by root canal therapy. During the 2-year follow-up, both teeth were functional and had no radiographic or clinical evidence of resorption or ankylosis.

Conclusion

The reported case highlights the favorably high tissue healing potential following severe dental trauma, given that appropriate treatment is performed. Correct endodontic management can guarantee the long-term prognosis of teeth following severe dental trauma.

Regenerative Endodontic Therapy in the Management of Nonvital Immature Permanent teeth: A Systematic Review and Meta-analysis

This meta-analysis is intended to evaluate the reliability of evidences published in current regenerative endodontic publications in a critical way. This meta-analysis is used to summarize and analyze the various clinical and radiographic findings associated with nonvital immature permanent teeth which have been treated with regenerative endodontic techniques. We also intend to significantly evaluate the worth of facts provided in the previous published literature. A structured electronic search by authors was undertaken in August 2020 using MEDLINE and PubMed search engine. The chosen parameters studied in this systematic review were presented in flowcharts and were summarized. We observed a good accomplishment rates in terms of survival of the treated tooth and also in resolution of any associated pathology in the apical areas; on contrary, our results in relation to apex closure along with constant root development, our findings from various studies were quiet variable. Regenerative endodontic procedures are constantly being restructured and enhanced to benefit present-day dentistry in all likely ways. Still, many factors that are important for the success of regenerative endodontic treatment outcomes still remain unexplained. There are still numerous gaps in our expertise at the present stage of this study.

Efficacy of i-PRF in regenerative endodontics therapy for mature permanent teeth with pulp necrosis: study protocol for a multicentre randomised controlled trial

BACKGROUND

Dental pulp necrosis, a common health problem, is traditionally treated with root canal therapy; however, it fails in restoring the vitality of damaged pulp. Most studies regarding regenerative endodontic therapy (RET) are limited to the treatment of immature necrotic teeth. Given that injectable platelet-rich fibrin (i-PRF) has shown great potential in regenerative medicine as a novel platelet concentration, this study is designed to explore whether i-PRF can serve as a biological scaffold, extending the indications for RET and improving the clinical feasibility of RET in mature permanent teeth with pulp necrosis.

METHODS

This is a randomised, double-blind, controlled, multicentre clinical trial designed to evaluate the clinical feasibility of RET for mature permanent teeth with pulp necrosis and to compare the efficacy of i-PRF and blood clots as scaffolds in RET. A total of 346 patients will be recruited from three centres and randomised at an allocation ratio of 1:1 to receive RET with either a blood clot or i-PRF. The changes in subjective symptoms, clinical examinations, and imaging examinations will be tracked longitudinally for a period of 24 months. The primary outcome is the success rate of RET after 24 months. The secondary outcome is the change in pulp vitality measured via thermal and electric pulp tests. In addition, the incidence of adverse events such as discolouration, reinfection, and root resorption will be recorded for a safety evaluation.

DISCUSSION

This study will evaluate the clinical feasibility of RET in mature permanent teeth with pulp necrosis, providing information regarding the efficacy, benefits, and safety of RET with i-PRF. These results may contribute to changes in the treatment of pulp necrosis in mature permanent teeth and reveal the potential of i-PRF as a novel biological scaffold for RET.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04313010 . Registered on 19 March 2020.

The effect of intracanal medication variations on microhardness of simulated immature root dentin

The effect of different medicaments and irrigation solutions on root dentin microhardness (MH) was evaluated depending on time. After initial measurements, MH of 60 maxillary incisors (n = 15 per group) was measured after 3 steps: irrigation with 2.5% sodium hypochlorite, exposure to medicaments [triple antibiotic (TAP) or calcium hydroxide (CH) pastes, 1 week or 1 month)] and final irrigation [20 mL of 17% EDTA or 20 mL 1% phytic acid (PA)]. The percentage of MH reduction was calculated. Data were analysed statistically at P < 0.05. Treatments caused a significant decrease in MH values compared to baseline and pre-measurements (P < 0.05). TAP significantly reduced the MH values of the samples over time (P < 0.05). Removal of TAP after 1 month with PA resulted in a significant reduction in MH compared to removing TAP after 1 week and CH removing after 1 month (P < 0.05). Considering the chemical preparation steps, the most hazardous effect on MH was observed after the first irrigation.

Antimicrobial and immunomodulatory in vitro profile of double antibiotic paste

AIM

To evaluate the antimicrobial and immunomodulatory activity of double antibiotic paste (DAP) in an in vitro infection model.

METHODOLOGY

The minimum inhibitory and bactericidal concentrations (MIC and MBC) and the antibiofilm activities (TTC assay) of DAP and its components (ciprofloxacin and metronidazole) were evaluated against Staphylococcus aureus and Enterococcus faecalis compared with triple antibiotic paste (TAP). The cellular viability of RAW 264.7 macrophages (24 and 72 h) and L929 fibroblasts (48 and 72 h) was evaluated by MTT. Furthermore, the production of TNF-α, IL-12, IL-6, IL-1α, IL-10 and NO (on RAW 264.7), besides IL-6, TGF-β and NO (on L929), stimulated with DAP in baseline and associated with heat-killed microbial-antigen conditions was measured by ELISA and Griess reaction. Data were analysed using the one-way ANOVA test with Bonferroni's corrections.

RESULTS

The MBC of pharmacopoeia DAP was similar to TAP for E. faecalis (0.25 μg.  mL^-1 ) and lower for S. aureus (DAP 1 μg. mL^-1 and TAP 2 μg. mL^-1 ; p < .001). Ciprofloxacin was the most effective antibiofilm drug from the pastes (35% of reduction for E. faecalis and S. aureus; p < .0001), and both pastes had a similar antibiofilm eradication against both biofilm species (29% and 35% for S. aureus and 76% and 85% for E. faecalis; p < .0001). DAP was cytotoxic against the tested cells. DAP significantly upregulated IL-1α (p < .001), IL-6 (p < .0001), TNF-α (p < .01) and IL-12 (p < .05; in the absence of antigens) and significantly reduced IL-6 (p < .0001; in the presence of HK-S. aureus) and IL-10 (p < .05; in the presence of both antigens) on macrophages. Furthermore, DAP upregulated IL-6 (p < .001) and NO (p < .05; in the absence of antigens), IL-6 (p < .001; in the presence of HK-S. aureus) and reduced NO (p < .001; in the presence of HK-S. aureus).

CONCLUSIONS

Double antibiotic paste and TAP had similar antimicrobial activity against S. aureus and E. faecalis. DAP upregulated pro-inflammatory cytokines mainly in the absence of antigens and had pro- and anti-inflammatory activity in RAW 264.7 macrophages and L929 fibroblasts in the presence of antigens involved in pulp infections.

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.

The Apical Extent of Mineral Trioxide Aggregate Apical Barrier Does not Influence the Treatment Outcome in a Nonvital Immature Permanent Anterior Tooth: A Split-Mouth Clinical Study

Objective:

The study aimed to compare treatment outcomes when MTA apical plugs are placed to different apical extents in nonvital immature permanent anterior teeth with an open apex.

Methods:

Six participants (five male & one female) between the age group of 8-18 years exhibiting bilateral traumatized nonvital immature permanent maxillary anterior teeth (n=12) with non-blunderbuss canal (Cvek’s stage 4) were included. Standardized endodontic procedures were performed, and an inter-appointment calcium hydroxide medicament placed for one week. Based on the apical position of the MTA apical barrier, two study groups were defined. Accordingly, Group I {(n=6) (4mm MTA plug up to the radiographic root end)} and Group II {(n=6) (4 mm MTA plug 2 mm short of the radiographic root-end)}. Teeth were obturated after twenty-four hours with thermoplasticized gutta-percha technique. They were evaluated clinically and radiographically at 12 and 24 months. Radiographs were assessed for periapical healing based on the periapical index (PAI) scores that were dichotomized as score <3 as healed and ≥3 as not healed. The data were compared using Mann Whitney U test, Kruskal Wallis and post hoc analysis.

Results:

At 24 months, all teeth in Group I and II were healed clinically and radiographically. On inter-group comparison, radiographically, all teeth (n=12) exhibited a PAI score <3 and were categorized as healed (P=1.00).

Conclusion:

The apical extent of MTA plug does not influence the treatment outcome. The clinician can place MTA apical plug either up to or 2 mm short of the radiographic root-end.

What is the best long-term treatment modality for immature permanent teeth with pulp necrosis and apical periodontitis?

PURPOSE

To evaluate and assess the current knowledge about apexification and regenerative techniques as a meaningful treatment modality and to map the scientific evidence for the efficacy of both methods for the management of traumatised immature teeth with pulp necrosis and apical periodontitis.

METHODS

This systematic review searched five databases: PubMed, Web of Science, Cochrane Library, Ovid (Medline), and Embase. Published articles written in English were considered for inclusion. The following keywords were used: Regenerative endodontic treatment OR regenerat* OR revital* OR endodontic regeneration OR regenerative endodontics OR pulp revascularization OR revasculari* OR 'traumatized immature teeth'. Only peer-reviewed studies with a study size of at least 20 cases followed up for 24 months were included. Eligibility assessment was performed independently in a blinded manner by three reviewers and disagreements were resolved by consensus. Subgroup analyses were performed on three clinical outcomes: survival, success, and continued root development.

RESULTS

Seven full texts out of 1359 citations were included and conventional content analysis was performed. Most of the identified citations were case reports and case series.

CONCLUSIONS

In the present systematic review, the qualitative analysis revealed that both regenerative and apexification techniques had equal rates of success and survival and proved to be effective in the treatment of immature necrotic permanent teeth. Endodontic regenerative techniques appear to be superior to apexification techniques in terms of stimulation of root maturation, i.e. root wall thickening and root lengthening. Knowledge gaps were identified regarding the treatment and follow-up protocols for both techniques.

Development of fibronectin-loaded nanofiber scaffolds for guided pulp tissue regeneration

Fibronectin (FN)-loaded nanofiber scaffolds were developed and assessed concerning their bioactive potential on human apical papilla cells (hAPCs). First, random (NR) and aligned (NA) nanofiber scaffolds of polycaprolactone (PCL) were obtained by electrospinning technique and their biological properties were evaluated. The best formulations of NR and NA were loaded with 0, 5, or 10 μg/ml of FN and their bioactivity was assessed. Finally, FN-loaded NR and NA tubular scaffolds were prepared and their chemotactic potential was analyzed using an in vitro model to mimic the pulp regeneration of teeth with incomplete root formation. All scaffolds tested were cytocompatible. However, NR and NA based on 10% PCL promoted the highest hAPCs proliferation, adhesion and spreading. Polygonal and elongated cells were observed on NR and NA, respectively. The higher the concentration of FN added to the scaffolds, greater cell migration, viability, proliferation, adhesion and spreading, as well as collagen synthesis and gene expression (ITGA5, ITGAV, COL1A1, COL3A1). In addition, tubular scaffolds with NA loaded with FN (10 μg/ml) showed the highest chemotactic potential on hAPCs. It was concluded that FN-loaded NA scaffolds may be an interesting biomaterial to promote hAPCs-mediated pulp regeneration of endodontically compromised teeth with incomplete root formation.

Outcomes of traumatised immature teeth treated with apexification or regenerative endodontic procedure: a retrospective study

This study compares the clinical success rate and continued radiographic root development of apexification and regenerative endodontic procedure in traumatised immature permanent teeth, and proposes a method to evaluate apical convergence, namely apical angle. Clinical and radiological data were collected from 44 treated teeth (22 with apexification and 22 with regenerative endodontic procedure). The preoperative and follow-up periapical radiographs were analysed to calculate the percentage changes in root length, root width, apical diameter and apical angle. The success rates for complete healing with apexification and regenerative endodontic procedure were 86.36% and 95.45%, respectively. Radiographically, regenerative endodontic procedure showed significantly greater percentage changes in root width only (P < 0.05). Apexification and regenerative endodontic procedure provide satisfactory outcomes concerning clinical success rates. Continued root development in regenerative endodontic procedure was similar to apexification, except for root width. Apical angle allowed us to assess the convergence of the root canal walls.

Regeneration of Pulp-Dentin Complex in a Tooth with Symptomatic Irreversible Pulpitis and Open Apex Using Regenerative Endodontic Procedures

Regenerative endodontic procedures are undertaken on permanent teeth with necrotic pulps and open apices in an attempt to resolve symptoms, to allow the continued development of the root(s), and to reestablish vitality. The available histologic analysis of these teeth has, in the majority of studies, shown that true regeneration of the pulp-dentin complex is not achieved. A recent investigation using an animal model outlined a procedure wherein pulpal amputation a few millimeters short of the apex followed by evoked bleeding allowed the complete regeneration of the normal pulp-dentin complex in immature vital teeth of ferrets. By implementation of this procedure, we report successful pulp regeneration outcome evidenced by continued root development and a positive response to pulp vitality tests in a maxillary central incisor with an open apex diagnosed with symptomatic irreversible pulpitis.