Perceptions of emergency department physicians regarding the management of traumatic dental injuries.

BACKGROUND/AIM: The purpose of this study was to investigate the self-reported confidence level and education of Atlantic Canada emergency department physicians in the management of traumatic dental injuries and to assess the need for further education surrounding the management of dental trauma. MATERIAL AND METHODS: An 18-item survey was developed and distributed electronically to physicians by their respective provincial medical associations. RESULTS: Traumatic dental injuries were reported in the emergency department on a weekly basis (78%). Most respondents reported that they were somewhat confident (51%) or very confident (7%) in managing traumatic dental injuries. Physicians' years in practice correlated positively with self-reported confidence levels in managing dental trauma. Urban and rural emergency department physicians reported similar levels of access to general dentists (38% and 30%, respectively); however, urban emergency department physicians reported greater access to pediatric dental specialists (43%) and oral and maxillofacial surgeons (81%) than rural practicing colleagues (4% and 30%, respectively). Most emergency department physicians (85%) agreed that it was important to receive training on the management of traumatic dental injuries and reported that education on managing traumatic dental injuries during residency (37%) and access to a dental trauma decision-making pathway (30%) would be of most value. CONCLUSIONS: This study highlights the role of emergency department physicians as first responders and demonstrates opportunities for improvement in the initial management of traumatic dental injuries. These implications can be achieved through the incorporation of further training in emergency medicine residency programs and through the implementation of decision-making pathways in emergency departments.

Effects of Intracanal Antimicrobials on Viability and Differentiation of Stem Cells From the Apical Papilla: An In Vitro Study.

BACKGROUND: Recent studies have indicated that intracanal antimicrobials used to disinfect the root canal in regenerative endodontic therapies (RETs) may be cytotoxic to stem cells from the apical papilla (SCAP), leading to inconsistent treatment outcomes. However, the effects of intracanal antimicrobial agents on the odontogenic differentiation capacity of SCAP at sub-lethal concentrations have not been investigated. The aim of this study was to determine the effects of intracanal antimicrobials on SCAP viability and odontogenic differentiation capacity using a clinically relevant concentration range (0.1-0.8 mg/mL). METHODS: Immature human third molars were collected from 71 patients and the apical papillae were harvested to form single-cell suspensions. The cytotoxic effects of intracanal antimicrobials including double antibiotic paste (DAP), triple or modified-triple antibiotic paste (TAP or MTAP), and calcium hydroxide (Ca(OH)2) on STRO-1+ SCAP were assessed using AlamarBlue and Live/Dead assays after exposing cells to treatment groups for 7 days at 0.1 to 0.8 mg/mL. The odontogenic differentiation potential of STRO-1+ SCAP was evaluated by immunocytochemistry staining of dentin matrix protein-1 and dentin sialophosphoprotein expression. RESULTS: All concentrations of TAP significantly reduced STRO-1+ SCAP viability and odontogenic differentiation (P < .001), whereas no DAP concentrations were significantly cytotoxic. Ca(OH)2 and MTAP concentrations below 0.4 mg/mL and 0.2 mg/mL, respectively, did not significantly reduce viability. The DAP, MTAP, and Ca(OH)2 did not significantly impact the odontogenic differentiation capacity of STRO-1+ SCAP. CONCLUSION: The varying effects of intracanal antimicrobials on STRO-1+ SCAP in vitro suggest amendments to the current root canal disinfection protocol may improve the success of RETs.

Temporal data series and logistic models reveal the dynamics of SARS-CoV-2 spike protein D614G variant in the COVID-19 pandemic

The COVID-19 pandemic is caused by the worldwide spread of the RNA virus SARS-CoV-2. Because of its mutational rate, wide geographical distribution, and host response variance this coronavirus is currently evolving into an array of strains with increasing genetic diversity. Most variants apparently have neutral effects for disease spread and symptom severity. However, in the viral spike protein, which is responsible for host cell attachment and invasion, the D614G variant, containing the amino acid substitution D to G in position 614, was suggested to increase viral infection capability. Here we propose a novel method to test the epidemiological impact of emergence of a new variant, by a combination of epidemiological curves (for new cases) and the temporal variation of relative frequencies of the variants through a logistic regression model. We applied our method to temporal distributions of SARS-CoV-2 D614 or G614, in two geographic areas: USA (East Coast versus West Coast) and Europe-Asia (East Countries versus West Countries). Our analysis shows that the D614G prevalence and the growth rates of COVID-19 epidemic data curves are correlated at the early stages and not correlated at the late stages, in both the USA and Europe-Asia scenarios. These results show that logistic models can reveal the potential selective advantage of D614G, which can explain, at least in part, the impact of this variant on COVID-19 epidemiology.

Fracture Resistance of Immature Teeth Submitted to Different Endodontic Procedures and Restorative Protocols.

INTRODUCTION: The purpose of this in vitro study was to determine whether the methods used to treat endodontically and restore anterior immature teeth with a necrotic pulp influence their resistance to fracture. METHODS: After access opening and cleaning and shaping, 80 specimen teeth were assigned into 5 groups according to the endodontic obturation method and coronal restoration as follows: A1, apexification with a composite restoration in the crown area; A2, apexification with a composite restoration in the crown and 3 mm into the root; IR, immediate revascularization with a composite restoration in the crown area; SR, successful revascularization with a composite in the crown area; and the control group, a mature tooth treated with gutta-percha and sealer with a composite restoration in the crown area. The teeth were mounted in acrylic blocks and brought to fracture under compressive forces in a universal testing machine. Both the fracture strength and the location where the fracture occurred were recorded. RESULTS: There were no statistically significant differences in the fracture resistance among the 5 groups (1-way analysis of variance, F4 = .545, P = .703). No statistically significant differences were found in the location where the fracture occurred either (χ24 = 4.1, P = .391). CONCLUSIONS: Within the limitations of this in vitro study, it can be concluded that the treatment options used to treat nonvital immature teeth provided the same resistance to fracture.

Neuropathy Mimicking Dental Pain in a Patient Diagnosed with Lyme Disease.

This report documents the case of a patient who developed neuropathy that presented as dental pain and was later diagnosed with Lyme disease. A healthy female patient presented to the endodontist with toothache symptoms. Her symptoms included intense pain in the left mandible irradiating into the temporalis area and through her neck and tingling on the lower left lip and left side of her tongue. She also reported feeling of sweats and chills the night before, as well as an altered sensation in her shoulder and arm. The pain was not alleviated by over-the-counter analgesics. Both intraoral and radiographic examinations did not reveal any abnormalities, and the patient was presented with the following differential diagnoses: cardiac issues, trigeminal neuralgia, and temporomandibular dysfunction. She presented to the emergency department at the local hospital for assessment on the same day. After some tests were performed, both a stroke and myocardial infarction were ruled out. The following morning, she noticed a bump in the posterior area of her left upper thigh where an erythema with a bull's-eye appearance was observed. She presented to her family doctor's office on the same day and was diagnosed with Lyme disease. Because Lyme disease can present with symptoms similar to a toothache, dentists should be knowledgeable of its manifestations. Lyme disease should be considered as differential diagnosis in patients who present with compatible symptoms and signs, which may occur in the orofacial region.

Resistance to fracture of extracted teeth used for pre-clinical endodontic procedures: Influence of storage conditions.

OBJECTIVES: The purpose of this in vitro study was to determine whether different storage conditions used during endodontic procedures affect the fracture resistance of extracted teeth used for pre-clinical dental education. METHODS: Freshly extracted mandibular incisors and canines were sterilised in an autoclave for 40 minutes at 24°F under a pressure of 20 psi and then stored in distilled water at 4°C until use. Specimens were randomly assigned to two groups based on the storage method used whilst undergoing endodontic procedures. Between endodontic sessions, teeth in the Wet Group (n = 16 incisors; n = 4 canines) were stored in distilled water and teeth in the Dry Group (n = 16 incisors; n = 4 canines) were stored in a dry container. All specimens were kept at room temperature and away from sunlight. Endodontic treatments were performed in 3 sessions over a 3-week period. The specimens were then brought to fracture under compressive forces along the long axis of the tooth in an Instron universal testing machine. The data were analysed using t tests (α = 0.05). RESULTS: None of the teeth fractured during endodontic procedures. However, the compressive load required to fracture teeth stored under wet conditions was significantly higher than the load needed for teeth stored dry (P < .05). CONCLUSIONS: Fracture resistance is affected by storage conditions; teeth stored in water have a higher resistance to fracture than teeth that are stored dry. Fracture resistance was, however, not reduced enough to lead to tooth fracture during pre-clinical endodontic procedures.

Biomaterials and Scaffold Design Strategies for Regenerative Endodontic Therapy.

Challenges with traditional endodontic treatment for immature permanent teeth exhibiting pulp necrosis have prompted interest in tissue engineering approaches to regenerate the pulp-dentin complex and allow root development to continue. These procedures are known as regenerative endodontic therapies. A fundamental component of the regenerative endodontic process is the presence of a scaffold for stem cells from the apical papilla to adhere to, multiply and differentiate. The aim of this review is to provide an overview of the biomaterial scaffolds that have been investigated to support stem cells from the apical papilla in regenerative endodontic therapy and to identify potential biomaterials for future research. An electronic search was conducted using Pubmed and Novanet databases for published studies on biomaterial scaffolds for regenerative endodontic therapies, as well as promising biomaterial candidates for future research. Using keywords "regenerative endodontics," "scaffold," "stem cells" and "apical papilla," 203 articles were identified after duplicate articles were removed. A second search using "dental pulp stem cells" instead of "apical papilla" yielded 244 articles. Inclusion criteria included the use of stem cells from the apical papilla or dental pulp stem cells in combination with a biomaterial scaffold; articles using other dental stem cells or no scaffolds were excluded. The investigated scaffolds were organized in host-derived, naturally-derived and synthetic material categories. It was found that the biomaterial scaffolds investigated to date possess both desirable characteristics and issues that limit their clinical applications. Future research investigating the scaffolds presented in this article may, ultimately, point to a protocol for a consistent, clinically-successful regenerative endodontic therapy.

Efeitos do laser de diodo de alta potência e da fotobiomodulação em dentes de ratos reimplantados tardiamente / Effects of high power diode laser and photobiomodulation therapy prior delayed replantation in rats

Resumo Introdução A busca por protocolos efetivos para reduzir a incidência de reabsorções radiculares e favorecer a reparação do ligamento periodontal perdido ainda representa um grande desafio, tendo em vista o prognóstico desfavorável dos reimplantes dentais tardios. Objetivo Avaliar, por meio da análise histológica, os efeitos do laser de alta potência e da fotobiomodulação na ocorrência de reabsorção radicular e no reparo periodontal, em dentes reimplantados tardiamente. Material e método Foram utilizados 50 incisivos centrais direitos de ratos Wistar. Após a extração, os espécimes foram divididos em cinco grupos (n = 10): G1 (controle positivo): reimplante imediato; G2 (controle negativo): reimplante tardio (RT): espécimes mantidos em ambiente seco por 60 minutos, sem tratamento adicional; G3: RT associado ao tratamento da superfície radicular com laser diodo de alta potência (810 nm, 1.5 W); G4: RT + superfícies radiculares e feridas alveolares tratadas com fotobiomodulação (laser diodo 660 nm, 30 mW e 780 nm, 40 mW, respectivamente); G5: RT + superfícies radiculares irradiadas com laser de alta e alvéolos com fotobiomodulação, nos mesmos parâmetros que G3 e G4, respectivamente. Após 60 dias, os animais foram eutanasiados. Os espécimes foram processados para análise histológica. Resultado G3 e G5 apresentaram as menores médias de scores com relação à ocorrência de reabsorções radiculares e anquilose, quando comparados a G2 e G4 (Teste Kruskall-Wallis, p<0,05). Com relação ao reparo periodontal, todos os grupos experimentais (G3, G4 e G5) apresentaram médias de escores inferiores (Teste Kruskall-Wallis, p<0,05) comparadas ao G1 e semelhantes ao G2 (Teste Kruskall-Wallis, p>0,05). Conclusão O laser de alta potência, associado ou não à fotobiomodulação, diminuiu a ocorrência das reabsorções radiculares e da anquilose, e a fotobiomodulação não favoreceu o controle das reabsorções radiculares nem o reparo periodontal.

Abstract Introduction The search for effective protocols for a lower incidence of root resorptions reduction and for a favor periodontal repair still represents a great challenge, considering the unfavorable prognostic of the delayed replanted tooth. Objective To evaluate by histologic analyses the effects of high power diode laser and photobiomodulation on the occurrence of root resorption and on the tissue repair of delayed replanted teeth. Material and method Fifty right central incisors of Wistar rats were used. After the extraction, the specimens were assigned to 5 groups (n=10): G1 and G2 were the control groups-with no treatment and they were respectively submitted to immediate and delayed replantation (DR- 60 minutes after the extraction). The other three groups received tissue repair treatment prior the DR: G3 - root surfaces were irradiated with high power laser (810 nm, 1.5 W); G4- root surfaces and the alveolar wounds were irradiated with low power laser (photobiomodulation), respectively with 660 nm, 90 mW and 780 nm, 40 mW; G5- root surfaces were irradiated with high power and the alveolar wound received photobiomodulation with the same parameters used in G3 and G4. After 60 days the animals were euthanized. The specimens were processed for histological analyses. Result The histologic analysis showed lower means values of scores of root reabsorptions and ankylosis in G3 and G5 when compared to G2 and G4 (Kruskall-Wallis test, p>0.05). Regarding the periodontal repair, all the experimental groups (G3, G4 and G5) presented lower means values of scores than G1 (Kruskall-Wallis test, p <0.05) and similar values to G2 (Kruskall-Wallis test, p>0.0.5). Conclusion High power laser reduced the occurrence of root resorption and photobiomodulation did not enhance the tissue healing process in delayed tooth replantation in rats.

Effect of Different Disinfection/Sterilization Methods on Risk of Fracture of Teeth Used in Preclinical Dental Education.

The aim of this in vitro study was to determine whether different disinfection/sterilization methods affected the risk of fracture of extracted teeth used for preclinical dental education. Freshly extracted intact mandibular incisors were assigned to different groups according to the processing method used. In the autoclave group (n=20), teeth were autoclaved for 40 min at 240°F under a pressure of 20 psi; in the formalin group (n=20), teeth were immersed in 10% formalin for two weeks; and in the control group (n=10), teeth were not processed. Teeth were then stored at 4°C in distilled water until use. Endodontic procedures were performed, and the fracture strength of the specimen was subsequently tested under compressive force along the long axis of the teeth using an Instron universal testing machine. The results showed that none of the specimens fractured during endodontic procedures. However, the compressive load needed to fracture the teeth was significantly less for the autoclaved teeth than the teeth stored in formalin or the control teeth (p<0.001). The disinfection/sterilization method used affected the fracture resistance of extracted teeth: autoclaved teeth were less resistant to fracture than teeth that were not sterilized or teeth that were chemically disinfected. However, fracture resistance was not reduced enough to lead to tooth fracture during preclinical endodontic procedures. Therefore, either processing method may be appropriate for teeth to be used for preclinical endodontic training.

Molecular characterization of hepatitis C virus in end-stage renal disease patients under hemodialysis

New direct-acting antiviral (DAA) agents are in development or already approved for the treatment of chronic hepatitis C virus (HCV) infection. The effectiveness of these drugs is related to the previous existence of resistant variants. Certain clinical conditions can allow changes in immunological characteristics of the host and even modify genetic features of viral populations. The aim of this study was to perform HCV molecular characterization from samples of end-stage renal disease patients on hemodialysis (ESRD-HD). Nested PCR and Sanger sequencing were used to obtain genetic information from the NS5B partial region of a cohort composed by 86 treatment-naive patients. Genomic sequences from the Los Alamos databank were employed for comparative analysis. Bioinformatics methodologies such as phylogenetic reconstructions, informational entropy, and mutation analysis were used to analyze datasets separated by geographical location, HCV genotype, and renal function status. ESRD-HD patients presented HCV genotypes 1a (n=18), 1b (n=16), 2a (n=2), 2b (n=2), and 3a (n=4). Control subjects were infected with genotypes 1a (n=11), 1b (n=21), 2b (n=4), and 3a (n=8). Dataset phylogenetic reconstruction separated HCV subtype 1a into two distinct clades. The entropy analysis from the ESRD-HD group revealed two amino acid positions related to an epitope for cytotoxic T lymphocytes and T helper cells. Genotype 1a was found to be more diverse than subtype 1b. Also, genotype 1a ERSD-HD patients had a higher mean of amino acids changes in comparison to control group patients. The identification of specific mutations on epitopes and high genetic diversity within the NS5B HCV partial protein in hemodialysis patients can relate to host immunological features and geographical distribution patterns. This genetic diversity can affect directly the new DAA's resistance mechanisms.

Molecular characterization of hepatitis C virus in end-stage renal disease patients under hemodialysis

New direct-acting antiviral (DAA) agents are in development or already approved for the treatment of chronic hepatitis C virus (HCV) infection. The effectiveness of these drugs is related to the previous existence of resistant variants. Certain clinical conditions can allow changes in immunological characteristics of the host and even modify genetic features of viral populations. The aim of this study was to perform HCV molecular characterization from samples of end-stage renal disease patients on hemodialysis (ESRD-HD). Nested PCR and Sanger sequencing were used to obtain genetic information from the NS5B partial region of a cohort composed by 86 treatment-naive patients. Genomic sequences from the Los Alamos databank were employed for comparative analysis. Bioinformatics methodologies such as phylogenetic reconstructions, informational entropy, and mutation analysis were used to analyze datasets separated by geographical location, HCV genotype, and renal function status. ESRD-HD patients presented HCV genotypes 1a (n=18), 1b (n=16), 2a (n=2), 2b (n=2), and 3a (n=4). Control subjects were infected with genotypes 1a (n=11), 1b (n=21), 2b (n=4), and 3a (n=8). Dataset phylogenetic reconstruction separated HCV subtype 1a into two distinct clades. The entropy analysis from the ESRD-HD group revealed two amino acid positions related to an epitope for cytotoxic T lymphocytes and T helper cells. Genotype 1a was found to be more diverse than subtype 1b. Also, genotype 1a ERSD-HD patients had a higher mean of amino acids changes in comparison to control group patients. The identification of specific mutations on epitopes and high genetic diversity within the NS5B HCV partial protein in hemodialysis patients can relate to host immunological features and geographical distribution patterns. This genetic diversity can affect directly the new DAA's resistance mechanisms.

Effects of diode laser irradiation and fibroblast growth factor on periodontal healing of replanted teeth after extended extra-oral dry time.

AIM: The search for effective protocols to reduce the incidence of root resorption and allow periodontal ligament repair is still challenging, given the unpredictable outcome of late tooth replantation. The aim of this study was to assess the effects of both high-power diode laser irradiation (DL) and basic fibroblast growth factor (FGF) on the periodontal healing of replanted teeth after extended extra-oral dry time. METHODS: Maxillary incisors of 50 male rats were extracted and assigned to three experimental and two control groups (n = 10). DL: root surfaces treated with DL (810 nm, continuous mode, 1.0 W, 30 s), FGF: topical application of FGF gel to the root surface and in the alveolar wound, DL + FGF: DL and topical application of FGF gel, C+: no treatment after extraction and immediate replantation and C-: no treatment after extraction and replantation after 60 min. In the experimental groups, the specimens were kept dry for 60 min, the pulps were removed and the canals were filled with calcium hydroxide paste prior to tooth replantation. The animals were euthanized after 60 days. The specimens were processed for radiographic, histological and immunohistochemical analyses. RESULTS: The radiographic analysis showed fewer resorptive areas in DL + FGF (P < 0.05). The histological and immunohistochemical analyses showed that the DL group had lower mean values of ankylosis, replacement and inflammatory resorption when compared to C-, not differing statistically from C+. DL + FGF produced significantly more collagen fibers (type I and type III) than C-, not differing from C+ in the case of type I fibers (P < 0.05). CONCLUSIONS: DL, with or without FGF, reduced the occurrence of external root resorption and ankylosis. Periodontal healing was favored and some fiber reinsertion occurred only when FGF was used.

Evidence of bottleneck effect on hepatitis C virus transmission between a couple under interferon based therapy

Issues on the correlation of viral genetic diversity and treatment response to the hepatitis C infection remain uncertain. The bottleneck effect dictates the characteristics of the viral population that will establish the infection in a new host and is related to how the immune system and treatment will be effective against the virus. Here we evaluated the phylogenetic characteristics of quasispecies population and the treatment response pattern of a HCV infected couple. We also analyzed whether the viral population of these patients indicated that they were exposed to the same source for primer infection. This study included two patients (P10 and P11) HCV genotype 1b infected. The couple presented horizontal transmission. Viral RNA was isolated from serum samples collected before, during and after treatment, at specific time points. The HCV NS5A gene sequence was amplified, cloned and sequenced. Genetic and evolutionary analyses were performed to compare the quasispecies population of these two patients and local control patients. Genetic distance and diversity were calculated. Phylogenetic analyses were performed by using maximum likelihood and Bayesian methodologies. The analysis of the baseline samples showed that the genetic distance of the viral populations of patients P10 and P11 was significantly lower than when these patients and the control group based on sequences from local patients were analyzed, supporting the horizontal transmission hypothesis. Phylogenetic analysis with sequences from all the time point samples also demonstrated two patterns of evolution depending on the treatment response. The Bayesian analysis showed that one isolate corresponding to the baseline sample of P10 was grouped into the P11 clade, suggesting a way of infection and a bottleneck effect. Our data suggests that the patient P11 viral population may be originated from variants from P10 patient and consequently showing that clinical differences between treatment responses can emerge from the bottleneck effect on viral populations.

Assessing the Impact of Voice-Over Screen-Captured Presentations Delivered Online on Dental Students' Learning.

The traditional lecturing method is still one of the most common forms of delivering content to students in dental education, but innovative learning technologies have the potential to improve the effectiveness and quality of teaching dental students. What challenges instructors is the extent to which these learning tools have a direct impact on student learning outcomes. The aim of this study was to assess the impact of a voice-over screen-captured learning tool by identifying a positive, nil, or negative impact on student learning as well as student engagement (affective, behavioral, and cognitive) when compared to the traditional face-to-face lecture. Extraneous variables thought to impact student learning were controlled by the use of baseline measures as well as random assignment of second-year dental students to one of two teaching conditions: voice-over screen-captured presentation delivered online and the traditional classroom lecture. A total of 28 students enrolled in the preclinical course in endodontics at a Canadian dental school participated in the study, 14 in each of the two teaching conditions. The results showed that, in most cases, the students who experienced the online lecture had somewhat higher posttest scores and perceived satisfaction levels than those in the face-to-face lecture group, but the differences did not achieve statistical significance except for their long-term recognition test scores. This study found that the students had comparable learning outcomes whether they experienced the face-to-face or the online lecture, but that the online lecture had a more positive impact on their long-term learning. The controls for extraneous variables used in this study suggest ways to improve research into the comparative impact of traditional and innovative teaching methods on student learning outcomes.

Glide Path Management with Single- and Multiple-instrument Rotary Systems in Curved Canals: A Micro-Computed Tomographic Study.

INTRODUCTION: Securing a reproducible glide path before instrumentation is recommended to maintain the original geometry of the root canal system and to prevent file separation. Mechanical glide path management systems have been introduced to expedite this step. The aim of this study was to compare apical transportation, canal volume increase, and working time during glide path management with ProGlider (PG; Dentsply Tulsa Dental Specialties, Tulsa, OK) and PathFiles (PF, Dentsply Tulsa Dental Specialties). METHODS: Forty curved mesial canals of mandibular molars were randomly allocated into 2 experimental groups (n = 20) according to the glide path management system: PG or PF. A glide path was achieved according to the manufacturers' protocol. Micro-computed tomographic analysis was performed to assess apical transportation at 1, 3, and 5 mm and volume increase. The time required to achieve the glide path was measured. RESULTS: The overall apical transportation mean values (± standard error) were 13.33 ± 3.37 µm for PG and 19.21 ± 4.4 µm for PF (P > .05). The mean (± standard error) volume increase values were 0.49 ± 0.06 mm(3) for PG and 0.48 ± 0.06 mm(3) for PF (P > .05). A statistically significant difference in the working time was found between the groups (P < .0001) where the mean (± standard error) values for time were 7.38 ± 1.73 seconds for PG and 20.61 ± 5.54 seconds for PF. CONCLUSIONS: Similar apical transportation and volume increase occurred during glide path management with PG single-file and PF multi-file systems; however, PG achieved glide path faster than PF.

Apical extrusion of debris in flat-oval root canals after using different instrumentation systems.

INTRODUCTION: The purpose of this study was to evaluate the amount of apically extruded debris in flat-oval root canal systems during cleaning and shaping with different instrumentation systems. METHODS: Seventy-two mandibular incisors were randomly assigned to 4 groups (n = 18) according to the instrumentation system to be used: the ProTaper Next rotary system (PTN; Dentsply Tulsa Dental, Tulsa, OK), the WaveOne reciprocating system (WO, Dentsply Tulsa Dental), the Twisted File Adaptive (TFA; SybronEndo, Orange, CA) rotary/reciprocating system, and the Self-Adjusting File (SAF) system (ReDent-Nova, Ra'anana, Israel). Debris extruded during the instrumentation was collected and dried in preweighed Eppendorf tubes. Three consecutive weights were obtained for each tube, and the average was calculated. The data were analyzed using the t test and analysis of variance (Games-Howell test). RESULTS: The SAF produced significantly more debris compared with the other systems (P < .05). No significant difference was noted amongst the PTN, WO, and TFA (P > .05). CONCLUSIONS: Regardless of the instrumentation system used, apical extrusion of debris was exhibited at some level, regardless of the instrumentation system used. The SAF was associated with the highest amount of debris extrusion compared with PTN, WO, and TFA.

Unilateral fusion of a supernumerary tooth to a maxillary permanent lateral incisor: a report of a rare case.

A supernumerary tooth is an additional entity to the normal series of teeth that may occur in isolation or may be fused to a normal counterpart. Diagnosis and delineation of an accurate treatment plan in cases involving supernumerary teeth are often a challenge. This report describes a case of unilateral fusion of a supernumerary tooth to a maxillary permanent lateral incisor in which a conservative approach was used to reach a favorable outcome.

Use of electronic apex locators may improve determination of working length.

DATA SOURCES: PubMed, LILACS, Science Direct, Cochrane Collaboration, NHS Evidence databases and in Evidence Based Dentistry and Journal of Evidence-Based Dental Practice. STUDY SELECTION: Randomised controlled trials (RCTs), clinical trials (CTs), diagnostic comparative studies and evaluation studies undertaken in adults where working length determination by both electronic and radiographic methods were used were considered. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently assessed study quality. RESULTS: Twenty-one studies were included, five RCTs and 16 in vivo diagnostic test studies. There was considerable heterogeneity between the EALs used and the study designs and a narrative summary of the findings were presented. Working length measurement was compared using three different methods: distance to the radiographic apex in teeth undergoing root canal treatment, (11 studies); concordance between the comparative measurements with EAL and radiography, (two studies); distance to specific anatomic apical reference points evaluated after tooth extraction (four studies)ded. The body of evidence was once again assessed as of low quality. CONCLUSIONS: Within the limitations of this review, it is suggested that working length determination by using EAL may perform better than radiography alone.

Assessment of smear layer removal protocols in curved root canals.

This study sought to assess if the final rinse protocol interferes with the smear layer removal in the apical area of curved canals. Sixty-four extracted human mandibular molars with curved mesial roots were instrumented with rotary files and divided into six experimental groups for final rinse: 1EDTA (syringe irrigation with 1 mL of 17% ethylenediaminetetraacetic acid (EDTA) ), 5EDTA (syringe irrigation with 5 mL of 17% EDTA), 1EDTA-P (syringe irrigation with 1 mL of 17% EDTA + pumping with gutta-percha point), 5EDTA-P (syringe irrigation with 5 mL of 17% EDTA + pumping with gutta-percha point), 1EDTA-EA (syringe irrigation with 1 mL of 17% EDTA + EndoActivator) and 5EDTA-EA (syringe irrigation with 5 mL of 17% EDTA + EndoActivator). Final rinsing was carried out over 3 min. The specimens were split lengthwise and observed under a scanning electron microscope using a score criterion. Comparison among the groups showed statistically significant difference only between the 5EDTA-EA group and the other groups (Kruskal-Wallis and Dunn's post-hoc tests, P < 0.05). The combination of 5 mL of 17% EDTA and 3 mL of 2.5% sodium hypochlorite (NaOCl) with the EndoActivator removed smear layer from the apical area of curved root canals more effectively than the other protocols used.