How is endodontics taught? A survey to evaluate undergraduate endodontic teaching in dental schools within the United Kingdom

Aim To evaluate the delivery of undergraduate endodontic education in UK dental schools using an online survey and to compare the results with those of a previous paper‐based survey (Qualtrough & Dummer 1997, Int Endod J, 30, 234). Aspects of delivery were also evaluated in comparison with the Undergraduate Curriculum Guidelines of the European Society of Endodontology (de Moor et al. 2013, Int Endod J, 46, 1105). Methodology An online version of an earlier paper‐based survey on undergraduate Endodontic education (Qualtrough & Dummer 1997, Int Endod J, 30, 234) was created. Invitations to take part were sent via email to the undergraduate endodontic programme leads in the 16 UK dental schools. Results The response rate was 94%. The current survey revealed greater convergence amongst dental schools than previously (Qualtrough & Dummer 1997, Int Endod J, 30, 234) on methods of canal preparation, disinfection and filling. Improvements were also noted in staff: student ratios, the involvement of teachers with advanced endodontic training and a greater diversity of teaching methods; developments which align with the recommendations of ESE Undergraduate Curriculum Guidelines (de Moor et al. 2013, Int Endod J, 46, 1105). The majority of schools appeared to be teaching contemporary instrumentation methods and were recommending the application of calcium silicate cements. The exposure of students to advanced topics included in the ESE Undergraduate Curriculum Guidelines (de Moor et al. 2013, Int Endod J, 46, 1105) such as surgical endodontic treatment, root canal re‐treatment and the management of complex cases was mixed. Conclusion Undergraduate endodontic training in the UK has advanced in the last 20 years with more consistency between schools and more contemporary methods adopted

The Micro-Shear Bond Strength of Various Resinous Restorative Materials to Aged Biodentine

Introduction: The type of materials and application time of veneering restorations on calcium silicate cements are important factors which influence the interfacial properties. The aim of this study was to measure the micro-shear bond strength of a resin composite (RC) using several adhesive systems and a resin-modified glass ionomer cement (RM-GIC) to different aged Biodentine specimens. Methods and Materials: A total of 15 Biodentine blocks were prepared and assigned to three aging periods: 12 min, one week and one month. Then they were subdivided into five sub-groups to receive cylinders of resinous materials. RC was applied using different adhesive systems: A) no adhesive B) etch and rinse C) two-step self-etch and D) universal adhesive in self-etch mode and E) RM-GIC applied directly over Biodentine. Micro-shear bond strength was measured and the data were analyzed using one-way and two-way ANOVA. The level of significance was set at 0.05. Result: There was significant interaction between Biodentine aging periods and resinous materials (P<0.05). The highest value was obtained in group D bonded to the recently set Biodentine. Increasing the aging period to one week resulted in increased micro-shear bond strength in all groups expect for group D. One-month incubation time led to reduced shear bond strength in group A, C and D. Micro-shear bond strength values of group E increased to the longer aged Biodentine. Conclusion: Group D showed the highest bond strength to freshly mixed Biodentine.Keywords: Bond Strength; Composite Resin; Dental Adhesive; Glass Ionomer Cement; Tricalcium Silicat

A comparative study of ProTaper Universal and ProTaper Next used by undergraduate students to prepare root canals

Introduction: The purpose of this study was to determine whether final-year undergraduate dental students achieved better shaping outcomes using the new ProTaper Next (PTN; Dentsply Sirona, Ballaigues, Switzerland) system to prepare root canals for the first time compared with the existing ProTaper Universal (PTU, Dentsply Sirona) system on which they had trained. A secondary aim was to explore the attitudes and preferences of the students toward both systems. Methods: Forty students prepared 1 simulated S-shaped canal using PTN and another with PTU. Images of the canals were saved before and after preparation, and the outcomes assessed included the formation of aberrations and the amount of resin removed at specific points along the canal length. Student opinions relating to PTN and PTU were collected via a questionnaire completed immediately after using the systems. For statistical analysis, the McNemar test was used to compare the incidence of aberrations, and a paired t test was used to analyze the width measurements. Responses to the questionnaire were analyzed using frequencies. Thus, the McNemar test was used for paired binary data and the marginal homogeneity test for categoric data when more than 2 categories were used. Finally, the overall preferences (either PTN or PTU) were analyzed using the sign/binomial test, which is a standard statistical test that allows us to determine if the proportion preferring one or the other is equal or not. Results: Canal ledges were formed in 30% of the canals prepared with PTU, whereas no ledges were formed with PTN (P < .001). A middle constriction, a form of canal aberration, was created by both systems although it occurred significantly (P = .006) more often with PTN. The ‘‘number of files’’ was judged by students to be significantly higher (P < .001) for PTU compared with PTN. Even though using PTN for the first time, students were more likely to recommend the system to other students for preparing S-shaped canals than PTU (P = .018) and preferred to use PTN in the future (P < .001). Conclusions: The students who had previous experience with the use of PTU were able to produce comparable shaping outcomes when they used PTN for the first time. For the preparation of S-shaped canals, the students preferred PTN over PTU in terms of the number of files and would prefer to use it in the future

Comparison of the Effect of Root Canal Preparation by Using Wave One and ProTaper on Postoperative Pain: A Randomized Clinical Trial

Introduction: WaveOne is a single-file reciprocating instrumentation system with the benefits of M-Wire alloy that has increased flexibility and improved resistance to cyclic fatigue over the conventional alloy. Root canal preparation techniques may cause postoperative pain. The goal of the present study was to compare the intensity and duration of postoperative pain when using WaveOne or ProTaper Universal systems for instrumentation of root canals. Methods: Forty-two patients who fulfilled specific inclusion criteria were assigned to 2 groups according to the root canal instrumentation technique used, WaveOne or ProTaper Universal. Root canal treatment was carried out in 2 appointments, and the severity of postoperative pain was assessed by numerical rating scale (NRS) score after each session until complete pain relief was achieved. Analgesic consumption, duration of pain, and root canal preparation time were also recorded. Results: The mean NRS score and duration of pain after both appointments were significantly higher in the WaveOne group (P < .05); however, the mean analgesic consumption was only significantly higher in the WaveOne group after the first appointment (P < .05). In all groups the highest mean NRS score was seen 6 hours after each therapeutic appointment. Canal preparation time was significantly shorter in the WaveOne group (P < .001). Conclusions: Postoperative pain was significantly lower in patients undergoing canal instrumentation with ProTaper Universal rotary instruments compared with the WaveOne reciprocating single-file technique

A critical analysis of research methods and experimental models to study working length determination and the performance of apex locators –A narrative review with recommendations for the future

Outcome studies have repeatedly shown that the apical endpoint of root canal preparation and filling is a determinate factor for the outcome of root canal treatment. Accurate determination of root canal length enhances the efficacy of chemo-mechanical disinfection and prevents over-/under-instrumentation and over-/under-filling in relation to the canal terminus. Long and short root canal fillings are consistently reported to be associated with higher rates of post-treatment endodontic disease. Although standards for undertaking and reporting diagnostic accuracy studies are available, publications dealing with the determination of root canal length are highly heterogeneous and describe procedures inconsistently. The aim of this review is to critically assess the methodology of publications in the past three decades. The process of planning, performing and analysing working length studies are presented stepwise with suggestions to optimize research methods

Overall Survival Benefit with Tebentafusp in Metastatic Uveal Melanoma

Background: Uveal melanoma is a disease that is distinct from cutaneous melanoma, with a low tumor mutational burden and a 1-year overall survival of approximately 50% in patients with metastatic uveal melanoma. Data showing a proven overall survival benefit with a systemic treatment are lacking. Tebentafusp is a bispecific protein consisting of an affinity-enhanced T-cell receptor fused to an anti-CD3 effector that can redirect T cells to target glycoprotein 100-positive cells. Methods: In this open-label, phase 3 trial, we randomly assigned previously untreated HLA-A*02:01-positive patients with metastatic uveal melanoma in a 2:1 ratio to receive tebentafusp (tebentafusp group) or the investigator's choice of therapy with single-agent pembrolizumab, ipilimumab, or dacarbazine (control group), stratified according to the lactate dehydrogenase level. The primary end point was overall survival. Results: A total of 378 patients were randomly assigned to either the tebentafusp group (252 patients) or the control group (126 patients). Overall survival at 1 year was 73% in the tebentafusp group and 59% in the control group (hazard ratio for death, 0.51; 95% confidence interval [CI], 0.37 to 0.71; P<0.001) in the intention-to-treat population. Progression-free survival was also significantly higher in the tebentafusp group than in the control group (31% vs. 19% at 6 months; hazard ratio for disease progression or death, 0.73; 95% CI, 0.58 to 0.94; P = 0.01). The most common treatment-related adverse events in the tebentafusp group were cytokine-mediated events (due to T-cell activation) and skin-related events (due to glycoprotein 100-positive melanocytes), including rash (83%), pyrexia (76%), and pruritus (69%). These adverse events decreased in incidence and severity after the first three or four doses and infrequently led to discontinuation of the trial treatment (2%). No treatment-related deaths were reported. Conclusions: Treatment with tebentafusp resulted in longer overall survival than the control therapy among previously untreated patients with metastatic uveal melanoma. (Funded by Immunocore; ClinicalTrials.gov number, NCT03070392; EudraCT number, 2015-003153-18.)

Reproductive success and contaminant associations in tree swallows (\u3ci\u3eTachycineta bicolor\u3c/i\u3e) used to assess a Beneficial Use Impairment in U.S. and Binational Great Lakes’ Areas of Concern

During 2010-2014, tree swallow (Tachycineta bicolor) reproductive success was monitored at 68 sites across all 5 Great Lakes, including 58 sites located within Great Lakes Areas of Concern (AOCs) and 10 non-AOCs. Sample eggs were collected from tree swallow clutches and analyzed for contaminants including polychlorinated biphenyls (PCBs), dioxins and furans, polybrominated diphenyl ethers, and 34 other organic compounds. Contaminant data were available for 360 of the clutches monitored. Markov chain multistate modeling was used to assess the importance of 5 ecological variables and 11 of the dominant contaminants in explaining the pattern of egg and nestling failure rates. Four of 5 ecological variables (Female Age, Date within season, Year, and Site) were important explanatory variables. Of the 11 contaminants, only total dioxin and furan toxic equivalents (TEQs) explained a significant amount of the egg failure probabilities. Neither total PCBs nor PCB TEQs explained the variation in egg failure rates. In a separate analysis, polycyclic aromatic hydrocarbon exposure in nestling diet, used as a proxy for female diet during egg laying, was significantly correlated with the daily probability of egg failure. The 8 sites within AOCs which had poorer reproduction when compared to 10 non-AOC sites, the measure of impaired reproduction as defined by the Great Lakes Restoration Initiative, were associated with exposure to dioxins and furan TEQs, PAHs, or depredation. Only 2 sites had poorer reproduction than the poorest performing non-AOC. Using a classic (non-modeling) approach to estimating reproductive success, 82% of nests hatched at least 1 egg, and 75% of eggs laid, excluding those collected for contaminant analyses, hatched

Multi-omics responses in tree swallow (\u3ci\u3eTachycineta bicolor\u3c/i\u3e) nestlings from the Maumee Area of Concern, Maumee River, Ohio

A multi-omics approach was utilized to identify altered biological responses and functions, and to prioritize contaminants to assess the risks of chemical mixtures in the Maumee Area of Concern (AOC), Maumee River, OH, USA. The Maumee AOC is designated by the United States Environmental Protection Agency as having significant beneficial use impairments, including degradation of fish and wildlife populations, bird or animal deformities or reproduction problems, and loss of fish and wildlife habitat. Tree swallow (Tachycineta bicolor) nestlings were collected at five sites along the Maumee River, which included wastewater treatment plants (WWTPs) and industrial land-use sites. Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo p dioxins and furans (PCDD/Fs), and chlorinated pesticide concentrations were elevated in Maumee tree swallows, relative to a remote reference site, Star Lake, WI, USA. Liver tissue was utilized for non-targeted transcriptome and targeted metabolome evaluation. A significantly differentially expressed gene cluster related to a downregulation in cell growth and cell cycle regulation was identified when comparing all Maumee River sites with the reference site. There was an upregulation of lipogenesis genes, such as PPAR signaling (HMGCS2, SLC22A5), biosynthesis of unsaturated fatty acids (FASN, SCD, ELOVL2, and FADS2), and higher lipogenesis related metabolites, such as docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (AA) at two industrial land-use sites, Ironhead and Maumee, relative to WWTP sites (Perrysburg and SideCut), and the reference site. Toledo Water, in the vicinity of the other two industrial sites and also adjacent to a WWTP, showed a mix of signals between industrial land-use and WWTP land-use. PAHs, oxychlordane, and PBDEs were determined to be the most likely causes of the differentiation in biological responses, including de novo lipogenesis and biosynthesis of unsaturated fatty acids

Antibiotic-prescribing for endodontic therapies: a comparative survey between general dental practitioners (GDPs) and final-year Bachelor of Dental Surgery (BDS) students in Cardiff, UK

AIM: To evaluate the views of final-year dental surgery (BDS; G1) students at Cardiff University and general dental practitioners (GDPs; G2) within the city of Cardiff, Wales on antibiotic prescribing for endodontic conditions, and investigate the potential differences between the two groups. METHODS: A cross-sectional online questionnaire-based survey of 12 qualitative and quantitative questions was distributed to 76 final-year BDS Cardiff University students and 55 dental practices within Cardiff, UK. Six questions recorded general information and the remaining questions included a series of hypothetical clinical scenarios, where the participants were asked to state whether they would or would not prescribe antibiotics. The data were analyzed using SPSS V23 to produce descriptive statistics, contingency tables, and to run Chi-Square (χ²) tests, Fisher's-exact tests, and relative-risk calculations. RESULTS: The response rate was 60% (n=79). All G1 were aware of the consequences of antibiotic over-use. Approximately 60% were aware of guidelines for antibiotic use in endodontic therapies, and 83% would only use antibiotics for a limited selection of patients (e.g. patients with systemic complications). G1 responses to clinical-scenarios indicated overall that they were comparable to the ideal answers except for acute apical abscess (64% believed that antibiotics were indicated). The majority of G2 were aware of the consequences of antibiotic over-use. Only 28% of G2 were aware of guidelines for antibiotic use in endodontic therapies. Overall responses revealed that antibiotics would be prescribed for: systemic complications (78%), acute apical abscess (72%) and symptomatic apical periodontitis (28%). The clinical-scenarios revealed G1 were more likely to prescribe antibiotics compared to G2 for cases of necrotic pulps with symptomatic apical periodontitis without systemic complications (Q7, incorrect indication) and less likely to other clinical scenarios such as necrotic pulps and asymptomatic apical periodontitis for patients with a history of rheumatic fever (ideal answer), symptomatic irreversible/reversible pulpitis, failure to achieve anaesthesia chronic apical abscess for patients with diabetes. The recognition of antibiotic prescription for cases with signs of spreading infection was more evident in G2. CONCLUSION: Final year undergraduate students were aware of the antibiotic resistance crisis, although a third were not aware of guidelines for use of antibiotics in endodontic conditions; their responses to clinical scenario were more compatible with the guidelines. General dentists were less aware of the implications of over-use of antibiotics and the existence of guidelines, and their responses were occasionally incompatible with antibiotic-guidelines for endodontic therapies. This article is protected by copyright. All rights reserved

Histologic tissue response to furcation perforation repair using mineral trioxide aggregate or dental pulp stem cells loaded onto treated dentin matrix or tricalcium phosphate

Objectives The aim of this study is to compare the effect of treated dentine matrix (TDM) and tricalcium phosphate (TCP) scaffolds on odontogenic differentiation and mineralization of dental pulp stem cells (DPSCs) in furcation perforations created in the pulp chamber floor of premolar teeth in dogs. Material and methods DPSCs were isolated and cultured from the dental pulp of the maxillary left second and third premolars of dogs. The DPSCs were loaded on TCP (SC+TCP) and TDM (SC+TDM) scaffolds and inserted into intentionally perforated pulp chamber floors of premolars in dogs; six teeth were used for each group. Three more groups of six specimens were created, and mineral trioxide aggregate (MTA), TDM, and TCP were inserted into the perforations to act as controls. An intact premolar and no treatment in the perforation site were used as positive and negative controls respectively. After 3 months, the animals were sacrificed and the type of inflammation, presence of dentine, continuation and type of cementum, type of connective tissue, and presence of foreign body reaction were evaluated, and significant differences were between groups determined using the Fisher’s exact test. The evaluation of the amount of inflammation and the percentage of new bone formation was evaluated using the Mann-Whitney U test. Results The negative control group was associated with severe inflammation and granulation tissue formation. In the positive control group, intact periodontal tissues and no inflammation were observed. Dentine bridge formation was not seen in specimens of any group. The specimens in the SC+TDM group were associated with significantly more bone formation than other groups (P < 0.001). The amount of inflammation was less than 10 % in specimens of all groups with the exception of three specimens in the TCP group that were categorized as 10–30 %. Chronic inflammation without foreign body reactions was the major pattern of inflammation in groups. Formation of cementum with a cellular and continuous appearance was seen in all specimens. Conclusions SC+TDM was associated with significantly more bone formation when used to repair uninfected furcation perforations in the premolar teeth of dogs. Clinical relevance Application of TDM as a biological scaffold in combination with DPSCs may offer an advantage during the repair of root perforation defects