Efficacy of non-instrumental Endodontic treatment in primary teeth: a systematic review of clinical randomized trials.

BACKGROUND: Endodontic therapy in pediatric dentistry is a challenging procedure, especially for special needs, uncooperative, and very young patients. A new conservative approach which is the non-instrumental endodontic treatment (NIET) has been developed to simplify the management of primary teeth requiring pulpectomy. This review aimed to compare the efficiency of NIET and conventional endodontic treatment in primary teeth. METHODS: Electronic databases including MEDLINE (via PubMed), Cochrane Library (CENTRAL), and Scopus without restrictions on publication year or publication language were searched. Only randomized clinical trials reporting clinical and radiographical outcomes of NIET and conventional pulpectomy on primary teeth were considered eligible. Two reviewers extracted the data according to the PRISMA statement and assessed the bias risk using the revised Cochrane risk-of-bias tool and a meta-analysis was performed. RESULTS: From 3322 screened articles, seven articles meeting the inclusion criteria were included. The selected studies included 283 primary molars, of 213 children aged between 3 and 9 years, treated by NIET and conventional pulpectomy, and had follow-up periods ranging from 1 month to tooth exfoliation. Two studies reported good success rates for both the NIET technique and endodontic therapy with no statistically significant difference while three studies showed radiographical significant differences with a low success rate for the NIET technique. Only one study reported better outcomes in the pulpectomy group with statistically significant differences. The quantitative grouping of the included studies showed no significant differences between NIET and conventional endodontic therapy regarding clinical and radiographical success (p value > 0.05). CONCLUSION: No difference between the NIET technique and the conventional endodontic therapy in primary molars requiring pulpectomy could be confirmed. Results of the present review need to be interpreted with caution since the quality of evidence according to the GRADE was considered as moderate to very low. Therefore, additional clinical trials on the NIET technique are recommended.

Laser Applications in Regenerative Endodontics: A Review.

Introduction: Developing regenerative endodontic treatment (RET) is an exciting approach to managing immature permanent teeth with pulp necrosis. RET is usually performed in two clinical steps: disinfection (first step) and tissue engineering (second step). Recently, laser therapy has entered the field of RET. This study aimed to provide an overview of the literature that employed laser therapy for root regeneration. Methods: A comprehensive search was performed on four databases, including PubMed, Web of Science, Scopus, and Google Scholar. The searched keywords were laser, regenerative endodontics, immature permanent teeth, and dental pulp necrosis, and related English-published articles were included up to October 2023. Results: Thirteen studies utilized a laser for RET. In the first step of RET, both high-power and low-level lasers (through photodynamic therapy [PDT]) may be applied for canal disinfection. In contrast, regenerative procedures in the second step of RET are just accelerated by low-power lasers (biostimulation). The literature does not support the benefit of laser-assisted irrigation in improving the clinical success of RET. There is some evidence that laser-assisted disinfection with a diode laser may provide comparable results to triple antibiotic paste in reducing bacterial counts in root canals while providing slightly better clinical and radiographic outcomes. PDT may be an effective and suitable adjunct to conventional disinfection methods in immature, necrotic teeth. Conclusion: Low-power lasers may be beneficial tools for improving the results of regenerative endodontics through chemical disinfection in the first step (PDT) or by biostimulation in the second step of RET.

Regenerative Endodontic Procedures in Immature Teeth Affected by Regional Odontodysplasia.

INTRODUCTION: Regional odontodysplasia (ROD) is a rare developmental disorder characterized by hypo-mineralization and hypoplasia of enamel and dentin. Symptoms include poorly developed tooth buds, delayed eruption of permanent teeth in affected quadrants, and ghost teeth. The affected teeth often become necrotic, due to abnormal enamel and dentin development, making them susceptible to caries and infection. The aim of this case report is to describe the treatment of ROD through pulp revascularization. CASE REPORT: A 13-year-old girl was referred for endodontic treatment. The mandibular left incisors and first premolar, which were affected by regional odontodysplasia, lost their vitality because of the impaired structure of the enamel. Due to the teeth's early developmental stage, a regenerative endodontic treatment was attempted. All three teeth were treated using the same protocol following the AAE guidelines. After 4 weeks treatment of the premolar was completed, whereas the incisor teeth remained symptomatic and were and therefore, intracanal dressing with calcium hydroxide was repeated and left in place for five months. Finally, the regenerative procedure was completed, and the crowns restored. The patient was scheduled for follow-up examinations after 6 months, and then yearly for the next 3 years. After one year, the periapical lesion around the central incisor and premolar had resolved, the lesion around the apex of the lateral incisor was healing, and the roots had continued to develop. After three years, complete healing and pulp canal obliteration were observed in the central incisor and in the premolar. However, the root of the lateral incisor tooth was split, and it was recommended to extract this tooth. CONCLUSION: The positive outcomes of regenerative endodontics in the central incisor and premolar suggest that revascularization of the pulp may be optional for the treatment of immature necrotic teeth affected by developmental disorders, such as ROD, amelogenesis imperfecta or dentinogenesis imperfecta.

Risk of pulp necrosis and related complications in the permanent anterior teeth with lateral luxation: A systematic review and meta-analysis.

This systematic review aimed to evaluate the evidence related to the occurrence of pulp necrosis and related complications in permanent anterior teeth with lateral luxation. It was envisaged to address the ambiguity related to the recommendation for pulp extirpation in teeth with mature root apex. An a priori protocol was formulated as per the best practices of evidence-based medicine and registered in PROSPERO. A comprehensive search was performed electronically in PubMed, LILACS, Web of Science, EMBASE, Scopus, and Cochrane on July 10,2023 without any restriction of language or year of publication. The screening of titles and abstracts and later the full-text articles were performed. Later, the data extraction was performed by using a self-designed sheet, risk of bias (ROB) assessment was done, meta-analysis was performed, and the GRADE approach was used to assess the quality of evidence. The qualitative synthesis was performed on 13 studies done from 1985 to 2020 in hospital settings. There was variability in the minimum and total observation periods, sample sizes, and characteristics of the sample population. The overall pooled prevalence of pulp necrosis was found to be 57% (95% CI: 42, 72%). It was 12% (95% CI: 8%, 18%, I2 = 0%) in immature teeth, and 58% (95% CI: 42, 73%, I2 = 86%) in mature teeth. The pooled prevalence of EIRR was found to be 11% (95% CI: 4, 27%, I2 = 95%) with greater risk in teeth with mature root apex (RR: 1.26, 95% CI: 1.12, 1.42, I2 = 0%). The ROB was moderate or high in nine studies and the GRADE of evidence was very low in 14 of 15 outcomes. There are greater chances of pulp necrosis in teeth with lateral luxation, especially with mature apex. However, it can still be less than 60% in most cases with the prevalence of EIRR less than 20%. Hence, an absolute recommendation for endodontic intervention in mature teeth with lateral luxation must be interpreted with slight caution.

Use of Endodontic Procedures in Young Permanent Teeth.

Background: Regenerative endodontic procedures (REPs) have emerged as a promising treatment option for young permanent teeth with pulp necrosis, offering the potential for tissue repair and preservation. Materials and Methods: A retrospective analysis was conducted on a cohort of 30 patients aged 8 to 16 years with pulp necrosis in young permanent teeth. The patients underwent REPs, including disinfection, triple antibiotic paste application, and a coronal barrier. Clinical and radiographic data were collected at baseline and follow-up appointments at 6, 12, and 24 months. Radiographs were analyzed for root lengthening, apical closure, and resolution of periapical lesions. Results: The mean increase in root length after 24 months was 3.42 mm (SD ± 1.12 mm), and 90% of cases demonstrated complete apical closure. The overall success rate, defined as the absence of clinical symptoms and radiographic evidence of pathology, was 80. Conclusion: REPs show promising outcomes in young permanent teeth with pulp necrosis, promoting root development, and apical closure.

Regeneración / revitalización pulpar en dientes permanentes inmaduros / Pulp regeneration / revitalization in immature permanent teeth

Introducción: El tratamiento pulpar de dientes inmaduros es un procedimiento desafi ante. Los dientes inmaduros tienen unos conductos anchos, paredes dentinarias delgadas y ápices abiertos, además de ser más propensos a la fractura y con mal pronóstico a largo plazo. La revascularización de un diente inmaduro intenta preservar los dientes el mayor tiempo posible, pero hay fracasos porque es difícil lograr una desinfección óptima del sistema de conductos radiculares. Métodos: Se realizó una búsqueda bibliográfi ca consultando las bases de datos electrónicas PubMed y Web of cience de los últimos 10 años, utilizando palabras clave y criterios de elegibilidad. Resultados: El proceso de búsqueda arrojó 635 artículos totales. Tras aplicar fi ltros, eliminar duplicados y seleccionar artículos por título y resumen, solo 27 fueron para el estudio. Conclusiones: La revitalización pulpar tiene altas tasas de supervivencia en el tratamiento de dientes permanentes inmaduros necróticos. Son necesarios ensayos clínicos aleatorios para comparar el efecto de la fi brina rica en plaquetas, el plasma rico en plaquetas y el sangrado inducido sobre la revitalización de un diente con pulpa necrótica. Uno de los principales problemas de la revitalización pulpar es la decoloración coronal. La triple pasta antibiótica es un agente antimicrobiano muy efi caz, pero las altas concentraciones podrían tener un efecto perjudicial sobre la supervivencia de las células madre. (AU)

Introduction: Treatment of affected immature teeth is a challenging procedure. Immature teeth have wide canals, thin dentin walls and open apices, in addition to being more prone to fracture and with a poor long-term prognosis. Revascularization of an immature tooth attempts to preserve the teeth as long as possible, but there are failures because it is diffi cult to achieve optimal disinfection of the root canal system. Methods: An exhaustive search was carried out by consulting the electronic databases PubMed and Web of Science of the last 10 years, using keywords and eligibility criteria. Results: The search process yielded 635 total articles. After applying fi lters, eliminating duplicates and selecting articles by title and abstract, only 27 were for the present study. Conclusions: Pulp revitalization has high survival rates in the treatment of necrotic immature permanent teeth. Randomized clinical trials are needed to compare the effect of platelet-richfi brin, platelet-rich plasma, and induced bleeding on the revitalization of a tooth with necrotic pulp. One of the main problems of pulp revitalization is coronal discoloration. Triple antibiotic paste is a very effective antimicrobial agent, but high concentrations could have a detrimental effect on stem cell survival. (AU)

Influence of systemic antibiotic therapy on the development and progression of induced apical periodontitis in Wistar rats.

The aim of this study was to investigate the influence of systemic antibiotic therapy on the development and progression of induced apical periodontitis (AP) in Wistar rats. Fifty-six rats were submitted to pulp exposure of the lower left first molar for the induction of AP. On the same day, intraperitoneal antibiotic therapy was administered once a day, for 15 days, until euthanasia. The groups were formed according to the different treatments (n = 8): C-control; GEN-treated with gentamicin (10 mg/Kg); AC-treated with amoxicillin (100 mg/Kg); MZ-treated with metronidazole (40 mg/Kg); AMP-treated with ampicillin (100 mg/Kg); AMC group-treated with amoxicillin + clavulanic acid (100 mg/kg); CLI-treated with clindamycin (60 mg/kg). After euthanasia, the jaws were collected and processed for (1) histological and histometric analysis using hematoxylin and eosin staining, (2) analysis of collagen fibers using Picrosirius Red staining and (3) bacteriological analysis using Brown-Brenn staining. The data were analyzed statistically (p < 0.05). AP induction was confirmed in all groups. The AMC group had the lower intensity of inflammatory infiltrate (p = 0.028) and less periapical bone resorption compared to control (p = 0.006). Regarding collagen maturation, PSR staining revealed a predominance of mature collagen fibers in all groups. The AC and AMC groups had the lower amount of mature fibers and the highest amount of immature fibers, compared to all other groups (p < 0.001). All groups showed bacterial contamination; however, the AC and AMC groups showed a lower extent of bacterial contamination compared to the control (p < 0.001). It can be concluded that systemic antibiotic therapy influences the development and progression of induced AP.

Healing and long-term prognosis of root-fractured permanent teeth: a retrospective longitudinal study.

AIM: The purpose of the present study was to evaluate permanent teeth with post-traumatic transversal root fractures, for their initial healing modality, the effect of candidate predictors and their long-term prognosis. METHODOLOGY: A retrospective longitudinal clinical study was conducted to evaluate records from patients bearing transversal root fractures in permanent teeth in order to radiographically assess short-term healing and non-healing events in the fracture line, their prognostic factors and their relationship with long term outcomes. The inter-fragmentary tissues were classified as healing: hard tissue (HT), connective tissue (CT) or connective tissue and bone (CT + B) and non-healing: interposition of granulation tissue (GT). A competing risk survival analysis was conducted to estimate the hazards of healing and non-healing events in the short-term and the effect of demographic, clinical, and treatment variables was assessed using the subdistribution regression model (Fine & Gray). RESULTS: Radiographic findings showed 61.4% of healing in the short-term being strongly influenced by the presence and type of concomitant injuries to the coronal fragment. Teeth with concomitant crown fractures (sHR 24.38, 95% CI [3.16-188.3], p = 0.0022), luxations with dislocations (sHR 10.58, 95% CI [1.37-81.9], p = 0.0240) and subluxations (HR 9.66, 95% CI [1.14-81.7], p = 0.0370) were more likely to present non-healing of root fractures in the short-term. The healing rate in the long-term was of 75.9%, most of them with interposition of bone and connective tissue. Kappa statistics demonstrated an overall agreement of 67.1% between short and long-term healing patterns, in special HT and CT + Bone modalities. CONCLUSION: Healing at the fracture site was the most frequent outcome, both in the short-term and in the long-term. Short-term healing modality was strongly influenced by the presence and type of concomitant injuries to the crown fragment, being the worst prognosis observed in root-fractured teeth with concomitant crown fractures, followed by concomitant luxations with dislocation. CLINICAL RELEVANCE: Post-traumatic transversal root fractures have a positive prognosis supporting therefore, a more conservative approach for these teeth before considering more radical treatments.

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

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

A retrospective cohort study of pulp prognosis in luxated permanent teeth: a competing risk analysis.

AIM: The present retrospective cohort study aimed to evaluate luxated permanent teeth for pulp prognosis and risk factors. METHODOLOGY: Case records and radiographs of 224 patients, involving 427 luxated permanent teeth, referred for treatment at the Dental Trauma Center-School of Dentistry, Universidade Federal de Minas Gerais, (DTC-SD-UFMG) from 2014 to 2022, were assessed for pulp prognosis classified as vitality, necrosis and pulp canal obliteration (PCO). A competing risk survival analysis estimated the hazards of the three outcomes, and the effect of demographic, clinical and treatment variables was tested using a cause specific Cox regression model. RESULTS: Pulp vitality was found in163 teeth (38.2%), pulp necrosis in 120 teeth (28.1%) and 55 teeth (12.9%) developed PCO. Pulp vitality decreased in the presence of concomitant crown fractures (HR 0.38 95% CI [0.2-0.8] p = 0.006). The risk of pulp necrosis (HR 0.62 95% CI [0.4-0.96] p = 0.03) was lower in cases with open apices but increased with concomitant crown fractures (HR 4.0 95% CI [2.6-6.1] p = 0.001) and intrusions (HR 2.3 95% CI [1.2-4.1] p = 0.007). Lateral or extrusive luxations (HR 3.0 95% CI [1.3-6.9] p = 0.001) and open apices (HR 2.4 95% CI [1.2-4.7] p = 0.01) showed higher rates of PCO. CONCLUSION: Type of luxation, the diameter of the apical foramen, and the presence of concomitant crown fractures were main determinants of pulp prognosis after luxation injuries in permanent teeth. CLINICAL RELEVANCE: Pulp prognosis after tooth luxation is dependent on the presence and direction of tooth displacement together with infection control. CLINICAL TRIAL REGISTRATION: Not applicable.

Evaluation of the modified 3Mix-Simvastatin combination in non-instrumental endodontic therapy of necrotic primary molars: A two-arm randomized controlled trial.

OBJECTIVE: This study aimed to assess the clinical and radiographic outcomes of non-instrumentation endodontic treatment (NIET) using a modified antibiotic mix of cefixime, ciprofloxacin and metronidazole with simvastatin (an anti-inflammatory, bone regeneration drug) on necrotic primary molars compared to conventional pulpectomy to help preservation of necrotic primary teeth until its natural exfoliation. MATERIALS AND METHODS: Forty mandibular primary second molars with necrotic pulp tissue from 38 healthy patients aged between 4 and 8 years were randomly assigned to two groups with a 1:1 allocation ratio. Group A teeth underwent conventional root canal treatment. The procedure involved a two-visit approach, employing k-files and h-files during the initial visit, followed by the application of calcium hydroxide paste as canal dressing between visits, while Group B teeth were treated with 3Mixtatin. All teeth were clinically evaluated after 1, 3, 6, and 12 months, and radiographically at 3, 6, and 12 months. Two external examiners assessed the results. Data analysis was conducted using a chi-square test at a 0.05 significance level. RESULTS: At the end of the follow-up interval, 90% of teeth in each group exhibited no clinical signs or symptoms. Additionally, inter-radicular radiolucency healing occurred in 75% of cases in the NIET group and 89.5% in the conventional pulpectomy group. However, no statistically significant difference was found between the two groups. CONCLUSION: NIET using 3Mixtatin seems to be a good alternative choice to conventional pulpectomy, offering a less complex treatment approach that may help avoid the complications associated with traditional pulpectomy and could be suitable for teeth with shorter roots.

Clinical, radiographic and histological findings of seven teeth from two California sea lions (Zalophus californianus) housed under professional care.

Seven teeth extracted from two adult California sea lions (Zalophus californianus) due to pulp exposure and/or to gain access to the mandibular canine teeth were histologically evaluated, and the findings were compared with clinical and radiographic findings. Three teeth were diagnosed with pulp exposure, and two of these showed no radiographic signs of endodontic disease and were histologically vital with prominent coronal pulpitis and a pulp polyp. Another tooth with pulp exposure was showing clinical and radiographic signs of endodontic disease and was histologically confirmed with pulp necrosis. A discoloured incisor tooth was showing radiographic signs of endodontic disease and was also histologically non-vital. Two clinically and radiographically healthy mandibular first premolar teeth and one second incisor tooth had no evidence of pulpitis or pulp necrosis but had pulp canal obliteration. Regular clinical and radiographic follow-up for 5 months to 3 years after the procedures confirmed uneventful healing of the extraction sites, despite initial flap's dehiscence. Although extractions of affected teeth in California sea lions are considered the most practical and beneficial therapy, these are associated with the risks of extensive trauma and anaesthesia and the need to perform these surgical procedures on-site under variable conditions. As California sea lions can be trained to allow conscious dental radiographic re-checks, monitoring teeth with clinical signs of pulp polyp formation and without radiographic signs of endodontic disease warrant further evaluation/reconsideration from previous recommendations. Endodontic treatment of abscessed teeth in California sea lions is reportedly unsuccessful and is discouraged. However, vital pulpectomy could be an alternative treatment to extraction in teeth with pulp polyps as it was found to be highly successful in humans, but the possibility of endodontic failure and need for further treatments should be weighted in the treatment choice.

Effect of root immaturity and depth of intrusion on spontaneous re-eruption and healing complications: A retrospective analysis.

BACKGROUND/AIMS: Dental trauma resulting in tooth intrusion is a severe injury of permanent dentition, with a prevalence of 0.5%-1.9% among traumatic dental injuries. Currently, treatment guidelines for intruded permanent teeth depend on root development and the degree of intrusion. However, the categorization of tooth maturity as mature or immature simplifies a complex continuum of root development stages. This study aims to investigate the impact of various stages of root development on the success of spontaneous re-eruption (SRE) of intruded teeth. MATERIALS AND METHODS: This retrospective study analysed data from 80 children (125 teeth) aged 6-12 years who experienced dental intrusion between 2018 and 2022. Root maturation was classified based on Cvek's classification, eight were categorized as stage 1, 29 as stage 2, 44 as stage 3, 25 as stage 4, and 19 as stage 5. Intruded teeth with immature roots (Cvek's class 1-4) underwent SRE, while mature teeth (Cvek's class 5) were treated with SRE, orthodontic repositioning, or surgical repositioning based on the degree of intrusion. Primary outcome measures were successful re-eruption and secondary outcomes included observed complications during follow-up. RESULTS: Regression analysis revealed that the patient's age, degree of root maturation, and degree of intrusion significantly affected spontaneous re-eruption (p < .05). SRE was more successful in teeth with Cvek's stages 1 and 2 compared to stages 3 and 4. Complications were associated with the treatment method, degree of root immaturity, and degree of intrusion. CONCLUSION: The study demonstrates that as root maturation progresses, the likelihood of re-eruption decreases, and the risk of pulp necrosis and infection increases. Therefore, teeth in later stages of immaturity (Cvek stage 4) should be repositioned orthodontically or surgically without waiting for spontaneous re-eruption.

The consequences of orthodontic extrusion on previously intruded permanent incisors-A retrospective study.

AIM: The aim of this study is to compare the adverse effects that occur after orthodontic extrusion of teeth that have been traumatically intruded with those of similar teeth that have not experienced any trauma. BACKGROUND: The outcome of incisors intrusion can be affected by the patient's age, extent of injury, root development, and malocclusion. Orthodontic extrusion is a potential solution, but it may also cause complications. MATERIALS AND METHODS: A retrospective study of the effects of extrusion of traumatically intruded teeth was carried out. The study group included 21 teeth in 14 patients. The control group included 32 teeth in 10 patients that underwent orthodontic extrusion with no history of trauma. Patients' age, gender, and stage of root development were recorded. The severity of the intrusion was classified as mild (<3 mm), moderate (3-6 mm), and severe (≥7 mm). A comparison of signs of pulp necrosis and root resorptions between the groups was made. RESULTS: The central incisor is the tooth that is most injured in 80.9% of cases. A majority of these incidents involve severe intrusion, which was found in 42.9% of cases. 90% of the traumatized teeth had already lost their vitality prior to orthodontic treatment. Various forms of root resorption were observed in the study group. In the control group, 31.2% of teeth showed signs of external root resorption, but no endodontic intervention was carried out during the follow-up period, as these teeth remained vital. CONCLUSIONS: Following intrusion, there is a high risk for root resorption and pulp necrosis. Orthodontic repositioning should be carried out with caution and mild force to prevent complications. Long-term follow-ups are required to ensure the best possible outcome.

The Incidence of Devitalization of Vital Teeth Associated with Pathologies of the Jaws Following Surgical Intervention: A Mixed-case Study.

AIM: The purpose of this mixed-case study is to explore the incidence of pulp necrosis of vital teeth after surgical treatment of adjacent lesions of the jaws. MATERIALS AND METHODS: The records of 341 biopsies submitted to the institute's histopathology laboratory were reviewed to include cases that met the inclusion criteria. About 84 biopsies collected from patients during surgical enucleation of lesions in proximity to healthy vital teeth were included of which 22 patients were recalled. Adjacent teeth were examined clinically and radiographically to assess their pulpal and periapical status after at least 8 months of follow-up. RESULTS: There were 7 different pathological lesions diagnosed histologically. The follow-up period ranged between 8 and 72 months; 12 cases (54.6%) have developed pulpal necrosis for at least one tooth after surgical enucleation of the lesion. The other 10 cases (45.4%) showed normal responses to sensibility testing for all the teeth adjacent to the lesion. Ten out of the 12 cases (83%) that underwent pulpal necrosis were associated with odontogenic cysts, whereas the remaining 2 were associated with periapical granuloma and fibrous dysplasia. CONCLUSION: Pulp necrosis is high in vital teeth associated with lesions without pulpal involvement. These teeth may benefit from root canal treatment prior to surgical enucleation of the lesion, which may prevent impaired healing or recurrence of infection. CLINICAL SIGNIFICANCE: Careful treatment planning and thorough discussion should take place between the surgeons, endodontists, and patients prior to executing the treatment. The patient should be aware that there is a possibility that they may need root canal treatment as a preventative measure to enhance the chances of healing following the surgical procedures and in case the patients opted not to perform root canal treatment beforehand, close follow-up in the future should take place to monitor the vitality of the teeth in the follow-up visits.

Indications for root canal treatment following traumatic dental injuries to permanent teeth.

The dental pulp may respond favourably or unfavourably to traumatic dental injuries. The most serious unfavourable responses are pulp necrosis and infection of the root canal system. These cause apical periodontitis and/or external inflammatory resorption of the tooth. The following injuries require root canal treatment as part of their emergency management-(A) complicated crown fractures (but some may be suitable for conservative pulp treatments, such as pulp capping, partial pulpotomy or pulpotomy), (B) complicated crown-root fractures, (C) supra-crestal coronal third root fractures and (D) injuries where pulp necrosis is predictable or highly likely to occur AND where there has been damage to the root surface and/or periodontal ligament with the aim of preventing external inflammatory resorption. This latter group of injuries are avulsion, intrusion, lateral luxation with a crown fracture, extrusion with a crown fracture (all in fully developed teeth) plus avulsion with a crown fracture and intrusion with a crown fracture (both in incompletely developed teeth). All other injuries should not have root canal treatment commenced as part of the emergency management, but they must be reviewed regularly to monitor the pulp for any adverse changes to its status, particularly pulp necrosis and infection of the root canal system.

Pulp regeneration: follow the guide / Régénération pulpaire : suivez le guide

Introduction: What if we changed our point of view? What if we approached endodontics from a biological perspective rather than a mechanistic one? What if, in the case of pulpal tissue necrosis, we were to consider an alternative to apexification therapies? Is pulp tissue regeneration now possible? Objective: Regenerative endodontic therapy (RET) aims to regenerate the pulp-dentin complex damaged by infection, trauma, or developmental anomaly of immature permanent teeth with necrotic pulp. The new intracanal tissue formation is expected to display pulp-like architecture and functions. There are two different based to tissue engineering approaches described to perform RET: cell-free CF-RET that attempt to induce host endogenous cells or stem cells to migrate into the root canal for regeneration or cell-based CB-RET which introduce exogenously prepared cells or stem cells into the canal for regeneration. Material and Method: CB-RET is the basis of current protocols recommended by the American Association of Endodontists (AAE) and the European Society of Endodontology (ESE) for the treatment of necrotic immature permanent teeth, with or without LIPOE. In this article, after defining the above-mentioned concepts, we will describe the ESE protocol and discuss the key steps for "getting started with endodontic regeneration". Conclusion: Each stage of the protocol must be carried out rigorously so as not to compromise the stages of the various biological processes involved. The practitioner has to stay informed of advances in knowledge resulting from research and new protocols to be published.

Introduction: Et si nous changions de point de vue ? Et si nous abordions l'endodontie d'un point de vue biologique et non mécanistique ? Et si, devant la nécrose du tissu pulpaire, nous envisagions une alternative aux thérapeutiques d'apexification ? La régénération du tissu pulpaire est-elle désormais possible ? Objectif: L'objectif des thérapeutiques régénératives endodontiques (regenerative endodontic therapy ou RET) est de récréer au sein du canal radiculaire un tissu semblable au complexe dentino-pulpaire tant sur le point de l'organisation cellulaire que sur le point fonctionnel. Deux concepts basés sur les principes de l'ingénierie tissulaire sont décrits : l'un basé sur la transplantation de cellules souches : le CB-RET (Cell-based RET) et l'autre basé sur le cell homing, c'est-à-dire sur le recrutement de cellules souches localisées à proximité de l'apex : le CF-RET (Cell-free RET). Matériel et méthode: Les protocoles actuels recommandés par l'Association Américaine des Endodontistes (American Association of Endodontists ou AAE) et la Société Européenne d'Endodontie (European Society of Endodontology ou ESE) dans le traitement des dents permanentes immatures nécrosées en présence ou non de lésion inflammatoire périapicale d'origine endodontique (LIPOE) sont basés sur le CF-RET. Dans cet article, après avoir défini les concepts cités précédemment, nous décrirons le protocole de l'ESE et discuterons des étapes clés pour « se mettre à la régénération endodontique ¼. Conclusion: Chaque étape du protocole doit être conduite avec rigueur afin de ne pas compromettre les étapes des différents processus biologiques engagés. Le praticien devra se tenir informé des avancées des connaissances issues des travaux de recherche et des nouveaux protocoles qui seront édités.

An Ex-Vivo Model for Investigating Bacterial Extrusion from Infected Root Canals during Masticatory Function.

INTRODUCTION: The extrusion of bacteria from infected root canals may lead to increase in symptoms, expansion of periapical lesions, and contribution to systemic diseases. The aim of this study is to investigate a potential proof-of-concept model to study the extent to which bacteria can escape from infected root canals under dynamic loading (simulated chewing). METHODS: The study was completed in 2 experiments performed at 2 institutions. Biofilms of Streptococcus intermedius in the first experiment and S. intermedius and Actinomyces naeslundii were allowed to grow in root canals of single-rooted extracted teeth for 3 weeks. The roots of the teeth were suspended in a small chamber containing dental transport medium and were mounted on a lower sample holder of a chewing simulator. In the experimental group, simulated chewing cycles equivalent to 1 year of function were conducted, and then bacterial migration was quantified and compared with stationary teeth. RESULTS: All experimental samples of the loading group revealed bacterial penetration in both experiments. Several of the unloaded samples revealed no bacterial penetration. In the first experiment, a significantly higher number of bacteria were able to escape into the periapex of the loaded group compared with the unloaded group (P = .017). In the second experiment, there was no significant difference between the 2 bacterial species used in the amount of extruded bacteria; however, there was a highly significant effect for occlusal loading (P = .0001). CONCLUSIONS: The potential for occlusal forces to enhance bacterial extrusion from infected root canals should be further explored.

External Inflammatory Root Resorption in Traumatized Immature Incisors: MTA Plug or Revitalization? A Case Series.

INTRODUCTION: External inflammatory root resorption (EIRR) in immature permanent teeth is a common complication after severe dental trauma. The management of this condition requires thorough disinfection of the root canal in order to arrest the resorptive process. However, current guidelines regarding the recommended treatment of EIRR following traumatic dental injuries vary, mainly in regard to the type of intracanal medication and its retention time in the root canal system. The objective of this case series was to present both the apical barrier technique (MTA plug) and revitalization procedures as valid treatment options in immature teeth with EIRR. METHODS: Four cases of post-traumatic immature teeth diagnosed with pulp necrosis and EIRR, with or without apical periodontitis, were treated either by an MTA plug (two teeth) or revitalization (two teeth). Cases were followed between 12 and 24 months. RESULTS: Both treatment methods were efficient in arresting EIRR and enabled bone healing. After revitalization, partial root maturation was observed. CONCLUSION: Whereas the key to achieve periodontal healing in cases of EIRR is thorough disinfection of the root canal, both a subsequent MTA plug as well as revitalization may represent adequate treatment methods. An additional benefit lies in the potential of revitalization to promote further root maturation through hard tissue apposition.

Genome-wide Association Study Identifies Novel Risk Loci for Apical Periodontitis.

INTRODUCTION: Apical periodontitis (AP) is a common consequence of root canal infection leading to periapical bone resorption. Microbial and host genetic factors and their interactions have been shown to play a role in AP development and progression. Variations in a few genes have been reported in association with AP; however, the lack of genome-wide studies has hindered progress in understanding the molecular mechanisms involved. Here, we report the first genome-wide association study of AP in a large and well-characterized population. METHODS: Male and female adults (n = 932) presenting with deep caries and AP (cases), or deep caries without AP (controls) were included. Genotyping was performed using the Illumina Expanded Multi-Ethnic Genotyping Array (MEGA). Single-variant association testing was performed adjusting for sex and 5 principal components. Subphenotype association testing, analyses of genetically regulated gene expression, polygenic risk score, and phenome-wide association (PheWAS) analyses were also conducted. RESULTS: Eight loci reached near genome-wide significant association with AP (P < 5 × 10-6); gene-focused analyses replicated 3 previously reported associations (P < 8.9 × 10-5). Sex-specific and subphenotype-specific analyses revealed additional significant associations with variants genome-wide. Functionally oriented gene-based analyses revealed 8 genes significantly associated with AP (P < 5 × 10-5), and PheWAS analysis revealed 33 phecodes associated with AP risk score (P < 3.08 × 10-5). CONCLUSIONS: This study identified novel genes/loci contributing to AP and specific contributions to AP risk in men and women. Importantly, we identified additional systemic conditions significantly associated with AP risk. Our findings provide strong evidence for host-mediated effects on AP susceptibility.