Postoperative pain after single-visit root canal treatments in necrotic teeth comparing instruments' kinematics and apical instrumentation limits - a prospective randomized multicenter clinical trial.

OBJECTIVES: This prospective randomized multicenter clinical trial (PRMCT) investigated postoperative pain after single-visit root canal treatments in teeth affected by pulp necrosis (PN), and asymptomatic apical periodontitis (AAP) (with apical radiolucent areas) or normal periradicular tissues (without apical radiolucent areas) comparing different instruments' kinematics and apical instrumentation limits. METHODS: Before chemomechanical preparation, 240 patients/teeth were randomly distributed into four groups (n = 60) according to the instruments' kinematics (rotary or reciprocating) and apical instrumentation limits (with or without intentional foraminal enlargement [IFE]). After that, specimens were submitted to the same irrigation and obturation techniques, and the patients were referred to undergo the definitive restorations. No medication was prescribed, but the patients were instructed to take either paracetamol (750 mg every 6 h for three days) or ibuprofen (600 mg every 6 h for three days) in pain cases. Postoperative pain incidence and levels were assessed at 24-, 48-, and 72 h following treatment completion according to a verbal rating scale (VRS) following a score. The Kolmogorov-Smirnov test was applied to assess the normality of the data. Mann-Whitney U, Chi-square, Friedman's ANOVA, and Friedman's multiple 2 to 2 comparison tests were employed to identify potential significant statistical differences among the variables in the study groups (P < .05). RESULTS: Significant statistical differences were only observed among the groups considering tooth, periradicular status, and the occurrence of overfilling (sealer extrusion) (P < 0.00). Patients with teeth instrumented through rotary kinematics and without IFE experienced lower rates of postoperative pain; however, this difference was relevant only at 24 h (P < 0.05). CONCLUSIONS: Postoperative pain was lower after using a rotary file system (Profile 04) inserted up to the apical constriction (AC). However, this finding was just statistically meaningful at 24 h. TRIAL REGISTRATION: This PRMCT was approved by the Human Research Ethics Committee of the Paranaense University - UNIPAR, Francisco Beltrão, PR, Brazil (CAAE. 46,774,621.6.0000.0109) on 02/09/2021. It was registered at The Brazilian Registry of Clinical Trials - ReBEC (RBR-3r967t) on 01/06/2023, was performed according to the Principles of the Helsinki Declaration and is reported following the Consolidated Standards of Reporting Trials Statement.

Impact of root canal preparation using two single-file systems on the intra-radicular microbiome of teeth with primary apical periodontitis.

OBJECTIVES: This study aimed to describe the effects of two single-file systems on the diversity of the endodontic microbiome of teeth with primary asymptomatic apical periodontitis. MATERIALS AND METHODS: The root canals from single-rooted teeth with apical periodontitis were prepared using either the Reciproc Blue (RB) or the XP-endo Shaper (XPS) instrument system. The latter was followed by a supplementary step with the XP-endo Finisher (XPF) instrument. For irrigation, 5.25% sodium hypochlorite was used. Root canal samples were taken at the baseline (S1), after preparation (S2), and after the supplementary step (S3). DNA was extracted and subjected to high-throughput sequencing using the MiSeq Illumina platform. RESULTS: Samples from 10 teeth from the RB and 7 from the XPS group were subjected to DNA sequencing. Initial samples differed significantly from post-preparation samples in bacterial diversity, with no significant difference when comparing the two instrument systems. The most dominant phyla in S2 were Bacteroidetes, Proteobacteria, Firmicutes, Fusobacteria, and Actinobacteria. The same phyla were found to dominate baseline samples and samples taken after using XPF, but with differences in the ranking of the most dominant ones. At the genus level, the most dominant genera identified after RB instrumentation were Bacteroidaceae [G-1], Fusobacterium, and Staphylococcus, while the most dominant genera after XPS instrumentation were Fusobacterium and Porphyromonas. These genera were also dominant in the initial samples. CONCLUSIONS: Both treatment protocols had measurable effects on the root canal microbial diversity, with no significant differences between them. Most of the dominant taxa involved in the primary infection and probably in the aetiology of apical periodontitis were eliminated or substantially reduced. CLINICAL RELEVANCE: The most dominant taxa that persisted after instrumentation were Fusobacterium, Porphyromonas, Staphylococcus, and Bacteroidaceae [G-1].

Guided Tissue Regeneration in Class IV External Cervical Resorption: A Case Report.

External cervical resorption (ECR) is a type of dental resorption that originates from the loss of the cementum's protective layer. The direct exposure of dentin to the periodontal ligament may lead to the invasion of clastic cells through an entry point on the external root surface into the dentinal tissue, causing resorption. Depending on the extension of ECR, different treatments are proposed. Although the literature presents distinct materials and methods for restoring ECR areas, an existing gap is related to care in the treatment of the supporting periodontal tissue. Guided tissue regeneration (GTR)/guided bone regeneration includes the stimulation of bone formation in bone defects using different types of membranes (resorbable and nonresorbable), regardless of its association with bone substitutes or grafts. Despite the benefits of guided bone regeneration, the application of this method in cases of ECR is still under-explored in the literature. Thus, the present case report uses GTR with xenogenic material and polydioxanone membrane in a case of class IV ECR. The success of the present case is related to the correct diagnosis and treatment plan. Complete debridement of resorption areas and restoration with biodentine were effective in tooth repair. GTR contributed to the stabilization of supporting periodontal tissues. The association of the xenogeneic bone graft with the polydioxanone membrane proved to be a viable option for restoring the health of the periodontium.

Root Canal Microbiome Associated With Asymptomatic Apical Periodontitis as Determined by High-Throughput Sequencing.

INTRODUCTION: Advanced DNA sequencing technology allows more detailed analysis and description of the endodontic microbiome. This study used the MiSeq high-throughput sequencing platform (Illumina, San Diego, CA) to describe the endodontic microbiome of teeth with primary asymptomatic apical periodontitis with no sinus tract. METHODS: Root canal samples from 25 patients were prepared for DNA sequencing analysis. Bacterial diversity of the microbiome was identified and compared between cases and according to the size of the related apical periodontitis lesions. Statistical analyses of the operational taxonomic unit distribution was performed using principal component analysis with the Bray-Curtis distance and a principal coordinate analysis, 2-way permutational multivariate analysis of variance. The chi-square or Fisher exact test was used to evaluate the prevalence of different operational taxonomic units related to small and large apical periodontitis lesions. RESULTS: Although there was a very high bacterial diversity in the microbiome of teeth with asymptomatic apical periodontitis, 4 phyla dominated the microbiome: Firmicutes (27%), Bacteroidetes (21%), Proteobacteria (21%), and Actinobacteria (12%). There was high variability in species composition between root canal samples with no common species pattern for the cases. Large lesions showed a higher number of species but did not significantly differ from small lesions in bacterial diversity indexes. Bacteroidaceae [G-1] bacterium HMT 272, a previously uncultivated but still unnamed and uncharacterized taxon, was the most prevalent and abundant phylotype. CONCLUSIONS: High-throughput sequencing technology confirmed the complexity of the endodontic microbiome and revealed that microbial heterogeneity is a feature between cases. This indicates that various microbial combinations of the endodontic microbiome are able to illicit periapical inflammatory diseases.

Limitations and Management of Static-guided Endodontics Failure.

Endodontic treatment in severely calcified canals is always a challenging task because it can result in accidents such as deviations or perforations. Recently, guided endodontics has become an alternative approach for pulp canal calcification, facilitating the location of root canals more predictably through the combined use of cone-beam computed tomographic imaging, oral scanning, and endodontic access guides. Although several reports have shown that guided endodontics is safer, faster and can be performed without an operating microscope and by less experienced operators, the technique has limitations, and iatrogenesis may occur. This article describes the limitations of static-guided endodontics and possible causes of failures. In the present case, not fixing the guide to the bone and inaccuracies generated by manually performing mesh merger software led to root perforation. Endodontic microsurgery was effective in resolving this case and should be considered the treatment of choice when guided endodontics cannot be used safely or when it fails.

Push-out bond strength and marginal adaptation of apical plugs with bioactive endodontic cements in simulated immature teeth.

OBJECTIVES: This study evaluates the bond strength and marginal adaptation of mineral trioxide aggregate (MTA) Repair HP and Biodentine used as apical plugs; MTA was used as reference material for comparison. MATERIALS AND METHODS: A total of 30 single-rooted teeth with standardized, artificially created open apices were randomly divided into 3 groups (n = 10 per group), according to the material used to form 6-mm-thick apical plugs: group 1 (MTA Repair HP); group 2 (Biodentine); and group 3 (white MTA). Subsequently, the specimens were transversely sectioned to obtain 2 (cervical and apical) 2.5-mm-thick slices per root. Epoxy resin replicas were observed under a scanning electron microscope to measure the gap size at the material/dentin interface (the largest and smaller gaps were recorded for each replica). The bond strength of the investigated materials to dentin was determined using the push-out test. The variable bond strengths and gap sizes were evaluated independently at the apical and cervical root dentin slices. Data were analyzed using descriptive and analytic statistics. RESULTS: The comparison between the groups regarding the variables' bond strengths and gap sizes showed no statistical difference (p > 0.05) except for a single difference in the smallest gap at the cervical root dentin slice, which was higher in group 3 than in group 1 (p < 0.05). CONCLUSIONS: The bond strength and marginal adaptation to root canal walls of MTA HP and Biodentine cement were comparable to white MTA.

The use of antimicrobial photodynamic therapy in the successful management of a nonsurgical complex type II Dens Invaginatus.

Because of its complex root canal morphology, dens invaginatus (DI) is a developmental anomaly that represents an endodontic challenge to complete cleaning, shaping, and disinfecting the root canal system. The present case report describes the use of antimicrobial photodynamic therapy as an adjunctive treatment in the successful management of nonsurgical complex type II DI in a left maxillary lateral incisor with thin and fragile dentin walls associated with periradicular lesion.

The use of antimicrobial photodynamic therapy in the successful management of an invasive cervical resorption class 4: A case report with five years follow-up.

A 41-year-old male with a dental history of invasive cervical resorption (ICR) was initially treated with a surgical endodontics approach and secondly with antimicrobial photodynamic therapy (aPDT) along with endodontic retreatment. The use of aPDT was essential to promote bacterial reduction in the resorption defect. Combining these techniques allowed for clinical, radiographic, and tomographic success after five years of follow-up.

The impact of the use of magnifying dental loupes on the performance of undergraduate dental students undertaking simulated dental procedures.

OBJECTIVES: This study aimed to evaluate the impact of the use of magnification (2.5x dental loupes) for third-year dental students in simulated endodontics and fixed prosthodontics assessments compared to those using no magnification. METHODS: Upon institutional review board exemption, third-year dental students were assessed during endodontics and fixed prosthodontics exams in the simulation laboratory. The endodontic group (n = 93) consisted of students who made an endodontic access preparation on a plastic lower left first molar (Nissan). The prosthodontic group (n = 86) consisted of students who made porcelain fused to metal preparation (PFM) on a plastic lower right first molar mounted on an acrylic lower jaw model (Columbia Dentoform). The impact of the use of dental loupes was evaluated. Assessment of the tasks was undertaken by experts-calibrated, blinded examiners-using a standardized marking rubric for each task. The statistical analysis included Chi-square test, one-way ANOVA, and Logistic regression. The level of significance adopted was 5%. RESULTS: Students' preparations using magnification were better compared with those without magnification. Students using magnification had a significantly higher pass rate than those not using magnification in both endodontic and prosthodontic groups (P < 0.05). CONCLUSIONS: In conclusion, third-year dental students who used loupes in the endodontics and prosthodontics simulation laboratory had significantly higher scores at the assessments.

Use of technology in endodontics by undergraduate dental students in a south-eastern state of Brazil.

INTRODUCTION: This study aimed to determine the level of incorporation of current technologies for endodontic treatment in undergraduate dentistry courses in a south-eastern state of Brazil. METHODS: For data collection, a self-assessment-based online questionnaire was created using the "Google Forms" platform, consisting of 12 multiple-choice and a few open-ended questions. The questions were related to the use of current technologies for diagnosis, imaging, use of ultrasonics in endodontics, instrumentation, use of apex locator, microscopy, photodynamic therapy and thermoplastic techniques during endodontic treatment. The questionnaire was sent to 54 dental schools in Minas Gerais. RESULTS: The results show low technological incorporation during the various stages of endodontic treatment by undergraduate students in dentistry courses in Minas Gerais. CONCLUSION: Despite the availability of several technologies to help perform different stages of endodontic treatment, it was observed that most universities do not teach the use of these technologies. Additional studies are needed to correlate how the lack of incorporation of these technologies could impact on the quality of the endodontic learning for undergraduate students.

Tratamento endodôntico de segundo molar inferior com presença de canal mesiomediano: relato de caso / Endodontic treatment of second mandibular molar with presence of middle mesial canal: case report

Introdução: A identificação de possíveis variações anatômicas é decisiva para o correto diagnóstico e planejamento da terapia endodôntica. Objetivo: Relatar o tratamento endodôntico de um dente #37, no qual foi identificado um terceiro canal na raiz mesial (canal mesio-mediano, CMM). Caso clínico: Dente #37 com diagnóstico de pulpite irreversível sintomática, foi encaminhado para realizar tratamento endodôntico. Durante o acesso coronário, e com auxílio de microscópio operatório (MO), foram identificadas trincas coronárias. Foi solicitada uma tomografia computadorizada de feixe cônico (TCFC), a partir da qual foi descartada a presença de trinca radicular. A TCFC possibilitou, também, identificar a presença de um terceiro canal na raiz mesial, localizado entre os canais mesiovestibular e mesiolingual. O tratamento endodôntico foi executado pelo sistema reciprocante WaveOne GOLD. A solução irrigadora de escolha para o preparo químico-mecânico foi o hipoclorito de sódio a 5,25%. Imediatamente antes da obturação, os canais foram irrigados com EDTA a 17%, para auxiliar na remoção da smear layer e, em seguida, foi realizada nova irrigação com hipoclorito de sódio a 5,25%. Os canais foram secos com pontas de papel absorvente e obturados pela técnica de onda contínua de condensação. Resultados: Os canais radiculares do dente #37 foram devidamente instrumentados e obturados. A paciente não apresentou qualquer sintomatologia pós-operatória, sendo encaminhada para a reabilitação protética final. Conclusão: A TCFC e o microscópio operatório foram decisivos para o correto planejamento do caso, tanto em relação à trinca observa- da quanto à detecção do canal mesiomediano (AU).

Introduction: Identification of possible anatomical variations is crucial for the correct diagnosis and planning of endodontic therapy. Objective: To report the endodontic treatment of tooth #37, in which a third canal was located in the mesial root (middle mesial canal - MMC). Methods: Tooth #37 was diagnosed with symptomatic irreversible pulpitis and referred for endodontic treatment. Coronary cracks were found during coronal access using a dental operating microscope (DOM). A cone-beam computed tomography (CBCT) was requested. CBCT revealed cracks involving the pulp chamber floor and a third root canal in the mesial root, between the mesiobuccal and the mesiolingual canals. Endodontic treatment was performed with the WaveOne GOLD reciprocating system. The chemical-mechanical preparation was performed with 5.25% sodium hypochlorite and 17% EDTA to remove the smear layer, followed by another irrigation with sodium hypochlorite. The canals were dried with absorbent paper points. The root canal obturation was performed with the continuous wave of condensation technique. Results: The root canals of tooth #37 were correctly instrumented and obturated. The patient did not present with any postoperative symptoms, and was referred for final prosthetic rehabilitation. Conclusion: CBCT and DOM were paramount for the correct planning of the case, as regards the presence of cracks and the detection of the middle mesial canal (AU).

Antimicrobial photodynamic therapy and guided endodontics: A case report.

A 35-year-old woman with a history of pulp canal obliteration (PCO) and apical periodontitis was treated with guided endodontics combined with antimicrobial photodynamic therapy (aPDT). The use of aPDT was paramount to the approach performed, and its application should be encouraged in cases of severely calcified canals when apical patency is unachievable. The combination of these techniques ensured successful clinical, radiographic, and tomographic outcomes at the 1-year follow-up. Key Words: Antimicrobial PDT, guided endodonics, periodontitis, pulp canal obliteration.

Quantitative Assessment of the Efficacy of Two Different Single-file Systems in Reducing the Bacterial load in Oval-Shaped Canals: A Clinical Study.

INTRODUCTION: This randomized clinical study compared the in vivo antibacterial efficacy of Reciproc Blue (RB), XP-endo Shaper (XP-S), and XP-endo Shaper associated with XP-endo Finisher (XP-F) systems in infected oval-shaped root canals with primary apical periodontitis. METHODS: In this study, 28 human teeth with a single root and a single canal were randomly assigned to 2 groups according to the instrumentation technique: group 1, RB (n = 14) and group 2, XP-endo (XP-S and XP-F, n = 14). The single-rooted teeth were prepared by reciprocating and rotary nickel-titanium instruments with 5.25% sodium hypochlorite irrigation. Samples were collected from the canal at the baseline (S1), after chemomechanical preparation (S2), and after XP-F instrumentation (S3). The DNA extracts were subjected to quantitative analysis for total bacterial counts by quantitative real-time polymerase chain reaction. The data were analyzed using the analysis of variance test, and the level of significance was set at 5%. RESULTS: All samples tested positive for the presence of bacteria at baseline, and the bacterial counts substantially reduced after treatment procedures (P < .01). The results showed no statistical difference between RB and XP-S instrumentation with respect to the bacterial reduction (P > .05). A marked bacterial reduction was observed after the use of the XP-F instrument (P < .01). CONCLUSIONS: The XP-S and RB systems sharply reduced the bacterial load in oval-shaped root canals with primary apical periodontitis. XP-F used as a supplementary instrument to chemomechanical preparation promoted a significantly higher bacterial reduction.

Antimicrobial Photodynamic Therapy associated with long term success in endodontic treatment with separated instruments: A case report.

This paper describes a case with a 5- year follow-up of Antimicrobial Photodynamic Therapy (aPDT) associated with long-term success in endodontic treatment in a tooth with separated instruments. The patient presented with a tooth exhibiting a periapical lesion, slight swelling, and severe pain. A radiograph revealed the presence of two separated files in the middle and apical thirds of the mesial root on a lower first molar. Attempts at bypassing were not successful. In the mesial root, instrumentation was limited to the coronal ends of the separated instruments. The apical patency could not be achieved due to the blockage of the separated files. aPDT was performed in two visits, at a 660-nm wavelength and 100 mW of power, for 90 s to a total energy of 9.0 Joules. Methylene blue solution was used as photosensitizer at concentration of 0005%. A 300-µm light diffusor was coupled to the diode laser and was inserted into the root canal 2 mm short of WL, where it was set to allow better diffusion of light. Each root canal was sealed with gutta-percha by warm vertical compaction and Pulp Canal Sealer™. After 5 years of follow-up, clear evidence of remineralization of the radiolucency and bone healing was observed. This case report suggests that the addition of aPDT to conventional endodontic treatment improved microbial disinfection leading to a successful long-term outcome.

Terapia fotodinâmica na endodontia: revisão de literatura / Photodynamic therapy in endodontics: review of literature

Objetivo: O presente estudo objetiva discutir os principais fatores que envolvem a terapia fotodinâmica e suautilização no tratamento endodôntico por meio de uma revisão de literatura. A persistência de microrganismosremanescentes ao preparo químico-mecânico ou a medicação intracanal está relacionada como a principal causa de insucesso na endodontia. Revisão de Literatura e Considerações finais: A terapia fotodinâmica desponta como uma promissora terapia antimicrobiana, sendo utilizada como coadjuvante ao tratamento endodôntico. Consiste numa técnica de fácil e rápida aplicação, que pode ser utilizada em sessão única ou múltiplas sessões, não desenvolvendo formas de resistência microbiana