Impact of Contracted Endodontic Cavities on Root Canal Disinfection and Shaping

IntroductionThe impact of minimally invasive endodontic procedures on root canal disinfection has not been determined. This ex vivo study compared root canal disinfection and shaping in teeth with contracted or conventional endodontic cavities.MethodsMandibular incisors with oval-shaped canals were selected and anatomically matched based on micro–computed tomographic (micro-CT) analysis and distributed into 2 groups. Conservative and conventional access cavities were prepared, and the canals were contaminated with a pure culture of Enterococcus faecalis for 30 days. Root canal preparation in both groups was performed using the XP-endo Shaper instrument (FKG Dentaire, La Chaux-de-Fonds, Switzerland) and 2.5% sodium hypochlorite irrigation. Intracanal bacteriologic samples were taken before and after preparation, and DNA was extracted and subjected to quantitative polymerase chain reaction. Micro-CT scans taken before and after preparation were used for shaping evaluation. Bacteriologic data were analyzed by the Poisson regression model and the chi-square test with Yates correction. Micro-CT data were analyzed by the Wilcoxon, Mann-Whitney, and Student t tests with the significance level set at 5%.ResultsAll initial samples were positive for E. faecalis. After preparation, the number of bacteria-positive samples was significantly higher in the contracted cavity group (25/29, 86%) than in the conventional cavity group (14/28, 50%) (P < .01). Intergroup quantitative comparison showed that the reduction in bacterial counts was also significantly higher in the group of conventional cavities (P < .01). Micro-CT data revealed no significant difference in the amount of unprepared areas between groups.ConclusionsOur findings showed that although shaping using an adjustable instrument was similar between groups, disinfection was significantly compromised after root canal preparation of teeth with contracted endodontic cavities.     

Endodontic teaching in Philippine dental schools

AIM: The aim of this study was to evaluate the pattern of undergraduate endodontic teaching in Philippine dental schools. METHODOLOGY: Data were gathered by sending questionnaires to the deans of the 23 dental schools in the country to determine details of the teaching of root canal treatment in permanent teeth. The covering letter requested that endodontic staff complete the questionnaire. RESULTS: Twenty of 23 dental schools returned completed questionnaires. Similarities were observed in the timing of undergraduate endodontic teaching, working length determination, and root canal preparation technique. Irrigating fluids recommended included one or a combination of the following: sodium hypochlorite, hydrogen peroxide, distilled water and EDTA. The root canal medicaments popularly employed were CMCP and eugenol. Most schools used slow-setting zinc oxide eugenol cement as sealer. Differences between schools were noted in the laboratory component of the course. The time allotted for the laboratory exercises, as well as the number of teeth used, differed greatly between each school. An inadequate tutor to student ratio was noted in the majority of schools. Teaching aids were limited and, in most instances, produced by faculty members. Most faculty members teaching endodontics had no specialist training. CONCLUSION: The results of this study have demonstrated that there is a need to review endodontic teaching in the majority of the Philippine dental schools to ensure that the course content and curriculum employed by all schools meet specified standards and that appropriate measures should be considered to enhance the learning experience of students.     

Endodontic hand instruments: cutting efficiency, instrumentation of curved canals, bending and torsional properties

Abstract In an assessment of the usefulness of different root canal instruments, two aspects are of particular interest for the endodontist: the cutting efficiency of the instruments and their ability id enlarge curved canals without undesirable changes of the canal shape such as the formation of zips and elbows. This review paper is based on own investigations on the cutting efficiency and instrumentation of curved canals. Additionally, two parameters which are described in ISO 3630-1, resistance to bending and resistance to fracture, are discussed. With regard to cutting efficiency in rotary motion, flexible stainless steel reamers and K-files clearly display the best results and are superior to conventional stainless steel as well as titanium-based reamers and K-files. Regarding cutting efficiency in linear motion, stainless steel Hedström files made by certain manufacturers are significantly superior to stainless steel and titanium-based Hedström files of other brands. Flexible stainless steel instruments with modified noncutting lips clearly produce the best canal shape in curved canals. With only rare exceptions, all the instruments tested fulfilled the requirements of the ISO standard concerning resistance to fracture and resistance to bending.     

New Bacterial Composition in Primary and Persistent/Secondary Endodontic Infections with Respect to Clinical and Radiographic Findings

Introduction

The aim of the present study was to analyze the microbiota of primary and secondary/persistent endodontic infections of patients undergoing endodontic treatment with respect to clinical and radiographic findings.

Methods

Samples from the root canals of 21 German patients were taken using 3 sequential sterile paper points. In the case of a root canal filling, gutta-percha was removed with sterile files, and samples were taken using sterile paper points. The samples were plated, and microorganisms were then isolated and identified morphologically by biochemical analysis and sequencing the 16S rRNA genes of isolated microorganisms.

Results

In 12 of 21 root canals, 33 different species could be isolated. Six (50%) of the cases with isolated microorganisms were primary, and 6 (50%) cases were endodontic infections associated with root-filled teeth. Twelve of the isolated species were facultative anaerobic and 21 obligate anaerobic. Monomicrobial infections were found for Enterococcus faecalis and Actinomyces viscosus. E. faecalis was most frequently isolated in secondary endodontic infections (33%). Moraxella osloensis was isolated from a secondary endodontic infection that had an insufficient root canal filling accompanied by a mild sensation of pain. A new bacterial composition compromising Atopobium rimae, Anaerococcus prevotii, Pseudoramibacter alactolyticus, Dialister invisus, and Fusobacterium nucleatum was recovered from teeth with chronic apical abscesses.

Conclusions

New bacterial combinations were found and correlated to clinical and radiographic findings, particularly to chronic apical abscesses. M. osloensis was detected in root canals for the second time and only in German patients.     

Influence of Bacterial Profiles in Cytokine and Clinical Features of Endodontic Disease

IntroductionWe verified the association between selected bacterial profiles and levels of cytokines, chemokines, and the expression of signs and symptoms of primary endodontic infection with apical periodontitis.MethodsSamples were collected from 21 root canals, and macrophages were stimulated for 24 hours. Tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-10, IL-12p70, interferon gamma, and chemokine (C-C motif) ligand 2 (CCL2) were measured using cytometric bead array. We investigated the overlapping networks between cytokines and chemokines with regression analysis. Checkerboard DNA-DNA hybridization was used to assess 40 target bacteria species. Using factor analysis, bacterial species aggregated in 2 factors. The association of bacteria species–based factors on cytokine and chemokine levels and clinical features was estimated with regression analysis.ResultsA negative relationship between IL-10 (anti-inflammatory cytokine) and CCL2, TNF-α, and IFN-γ (proinflammatory cytokines) (all P < .05) was observed. CCL2 was positively correlated with TNF-α (P < .01). Thirty-eight bacteria species were detected in primary endodontic infection with apical periodontitis. The first bacteria species–based factor was associated with the size of the radiolucent area (coefficient = 15.42) and tenderness to percussion/pain on palpation (coefficient = 20.79). The second factor was associated with CCL2 levels (coefficient = 1.28).ConclusionsDifferent bacterial profiles can be differentially related to the expression of inflammatory proteins and the experience of clinical features.     

Long-term Outcomes of Endodontic Treatment Performed with Resilon/Epiphany

Introduction

Resilon (Resilon Research LLC, Madison, CT) with Epiphany Sealer (Pentron Clinical Technologies, Wallingford, CT) was introduced into the market in 2004 as a new method of root canal obturation. This material as well as the traditionally used gutta-percha with AH Plus sealer (Dentsply Maillefer, Tulsa, OK) were in use over a 9-year span in the University of North Carolina endodontic clinics. Although Resilon was initially thought to create a “monoblock” seal between the material and the canal, in vitro studies later suggested this concept not to be true. The long-term outcome of Resilon using a validated radiographic index and a systematic approach has not been reported. The purpose of this retrospective cohort study was to radiographically evaluate the outcome of Resilon/Epiphany-treated root canals compared with traditional gutta-percha/AH Plus.

Endodontic treatment of experimental root perforations in dog teeth

Abstract Experimental root perforations were made in 131 teeth of 5 mongrel dogs. The perforations were treated according lo five different endodontic techniques and the results were observed after 3 weeks, 3 months and 1 year. The histologic reaction was dominated by inflammation and downgrowth of gingival epithelial tissue, regardless of observation time, technique or material Used. The epithelial downgrowth resulted in the formation of periodontal pockets with the epithelial attachment apical to the perforation. The frequency of the periodontal pockets increased with increasing observation time and after 1 year 75% of the perforations were lined with epithelium. The inflammation at the perforation site apparently was maintained by irritants from the periodontal pockets.     

Operator-related aspects in endodontic malpractice claims in Finland

Objective: We analyzed operator-related differences in endodontic malpractice claims in Finland.

Materials and methods: Data comprised the endodontic malpractice claims handled at the Patient Insurance Centre (PIC) in 2002–2006 and 2011–2013. Two dental advisors at the PIC scrutinized the original documents of the cases (n?=?1271). The case-related information included patient’s age and gender, type of tooth, presence of radiographs, and methods of instrumentation and apex location. As injuries, we recorded broken instrument, perforation, injuries due to root canal irrigants/medicaments, and miscellaneous injuries. We categorized the injuries according to the PIC decisions as avoidable, unavoidable, or no injury. Operator-related information included dentist’s age, gender, specialization, and service sector. We assessed level of patient documentation as adequate, moderate, or poor. Chi-squared tests, t-tests, and logistic regression modelling served in statistical analyses.

Results: Patients’ mean age was 44.7 (range 8–85) years, and 71% were women. The private sector constituted 54% of claim cases. Younger patients, female dentists, and general practitioners predominated in the public sector. We found no sector differences in patients’ gender, dentists’ age, or type of injured tooth. PIC advisors confirmed no injury in 24% of claim cases; the advisors considered 65% of injury cases (n?=?970) as avoidable and 35% as unavoidable. We found no operator-related differences in these figures. Working methods differed by operator’s age and gender. Adequate patient documentation predominated in the public sector and among female, younger, or specialized dentists.

Conclusions: Operator-related factors had no impact on endodontic malpractice claims.     

Case Reports in Maxillary Posterior Teeth by Guided Endodontic Access

The localization of partial or completed root canal obliteration is a challenging task in endodontic practice. Recently, guided endodontics has become an alternative solution for those cases. Although this technique has already been used clinically in managing anterior teeth, in this report, we describe 3 complex clinical scenarios of calcified root canals of 1 molar and 2 premolars using guided endodontics. The clinical cases reported here show that technological evolutions should make guided endodontic procedures more widespread because their execution is relatively fast and safe even in the case of the upper molar. Additionally, 12-month clinical follow-up visits showed the effectiveness of the guided endodontic procedures.     

Prevalence of Candida Species in Endodontic Infections: Systematic Review and Meta-analysis

Introduction

Candida in endodontic infections has been investigated in a large number of studies, but its role as an endodontic pathogen is still debatable. The aim of this study was to systematically review the literature on the prevalence of Candida species in root canal infections.

Root Canal Irrigants and Medicaments in Endodontic Malpractice Cases: A Nationwide Longitudinal Observation

Introduction

The aim of this study was to assess the role of root canal irrigants and medicaments in endodontic injuries verified in Finland and to estimate the rate of such events over time.

Factors Associated with the Need for a Primary Endodontic Treatment after Single-Unit Crown Cementation: A Retrospective Case-Control Study

IntroductionThis case-control study aimed to identify factors associated with an increased risk for endodontic treatment after single-unit crown cementation and to describe the timeline of such events.MethodsAfter evaluating the electronic records of all single-unit crowns placed on nonendodontically treated teeth between 1999 and 2019 and excluding teeth with preexisting questionable or confirmed endodontic disease, “cases” were identified as teeth requiring primary endodontic treatment after crown cementation. This was not examined in the current study because the cases and controls were matched by tooth type.ResultsOverall, 69 teeth without any suspected or confirmed past endodontic disease required an endodontic intervention after crown cementation. The mean number ± standard deviation of restorations in a tooth before crown cementation was significantly higher among the cases than the matched controls (2.16 ± 0.99 vs 0.78 ± 0.78, P < .05). Teeth with ≥2 and ≥3 previous restorations had an almost 4 (odds ratio = 3.81; 95% confidence interval, 1.56–9.29; P < .05) and almost 6 (odds ratio = 5.97; 95% confidence interval, 1.230–28.95; P < .05) times higher risk, respectively, for endodontic treatment after crown cementation compared with teeth with ≤1 restoration present before crown cementation. The majority (65%, n = 45) of teeth in the cases group required endodontic treatment during the first 3 years after crown cementation.ConclusionsThe presence of multiple restorations at the time of crown cementation was identified as a significant predictive factor for the need for endodontic treatment after crown cementation in teeth with no preexisting questionable or confirmed endodontic disease. Therefore, clinicians should be aware and inform patients about the increased risk of primary endodontic treatment in teeth with a history of more than 1 restoration, especially during the first 3 years after permanent crown cementation.     

Comparison between two ultrasonic units in shaping curved canals in teeth using macroradiography

Abstract The efficacy of two ultrasonic units in shaping curved canals in teeth were compared. Twenty teeth were instrumented using the Cavi-Endo unit at a power setting 1 using the technique recommended by the manufacturer. Another group of 20 teeth received similar treatment but were instrumented with the Enac unit. The time taken to instrument each canal was recorded. The pre- and post-instrumented radiographs of the teeth of x 10 magnification were taken using a microfocal technique. The radiographs were subjected to a subtraction technique to result in composite images of the pre- and post-instrumented shapes. The canal shape and the incidence of elbows were evaluated using various measurements taken from the radiographs. The manner the dentine was removed was similar in both groups. All canals exhibited unequal removal along the canal with more dentine being removed at the coronal end. The Enac group exhibited a higher incidence of elbows which occurred further apically than those in the Cavi-Endo group. There was no significant difference between groups in the following: time of instrumentation, amount of apical and coronal canal enlargement, apical deviation and change in width at the elbow. These findings were no different from those of another study using simulated canals.     

Endodontic Specialists' Practice During the Coronavirus Disease 2019 Pandemic: 1 Year after the Initial Outbreak

IntroductionThe aims of this observational study were to determine if endodontists' practices in early 2021 experienced changes in patient characteristics compared with a comparable prepandemic period and to determine whether the changes reported during the initial outbreak of coronavirus disease 2019 (COVID-19) in 2020 were reversed 1 year later.MethodsDemographic, diagnostic, and procedural data of 2657 patient visits from 2 endodontist private offices from March 16 to May 31 in 2019, 2020, and 2021 were included. Bivariate analyses and multiple logistic regression models were used to examine the impact of ongoing COVID-19 pandemic on patient data.ResultsBivariate analyses showed that patients' self-reported pain levels and the number of visits with irreversible pulpitis in 2021 were higher than 2019 (P < .05). Patients' self-reported pain, percussion pain, and palpation pain levels in 2021 were less than 2020 (P < .05). Multiple logistic regression analyses showed that endodontists' practices in 2021 had an increase in the number of nonsurgical root canal treatments (odds ratio [OR] = 1.482; 95% confidence interval [CI], 1.102–1.992), and apicoectomies (OR = 2.662; 95% CI, 1.416–5.004) compared with 2019. Compared with the initial outbreak in 2020, endodontists' practices in 2021 had visits with older patients (OR = 1.288; 95% CI, 1.045–1.588), less females (OR = 0.781; 95% CI, 0.635–.960), more molars (OR = 1.389; 95% CI, 1.065–1.811), and less pain on percussion (OR = 0.438; 95% CI, 0.339–0.566).ConclusionsThe ongoing COVID-19 pandemic was associated with an increase in the number of nonsurgical root canal treatments. Some of the changes observed during the initial outbreak in 2020, including objective pain parameters, returned to normal levels 1 year later.     

Periapical status, quality of root canal fillings and estimated endodontic treatment needs in an urban German population

Abstract The objective of this study was to determine the periapical status and the quality of root canal fillings and to estimate the endodontic treatment needs in a German population. Clinical and radiographic data and the operative procedures performed were evaluated on 323 patients coming to a dental surgery in Stuttgart, Germany, in 1993. In 182 individuals at least one tooth exhibited a root canal filling, a necrotic pulp or an irreversible pulpitis. Out of the 7897 teeth examined, 215 (2.7%) had a root canal treatment (category A), 122 being nonendodontically treated (1.5%) did not respond to the sensitivity test (category B) and 53 (0.7%) were diagnosed as having irreversible inflamed pulp tissue (category C). The prevalence of teeth associated with radiographic signs of periapical pathosis was 61 % in the group of root canal filled teeth and 88% in the group of pulpless and non-endodontically treated teeth. Using the level and the density of the root canal filling as criteria for evaluating the technical standard, only 14% of the endodontic treatments of non-apicectomized teeth were qualified as adequate. The minimal endodontic treatment need is 2.3% related to all examined teeth when the root canal filled teeth with clinical symptoms of periapical periodontitis (category A) and those of categories B and C are included. The real endodontic treatment need is suggested to be larger when considering that the technical quality of the obturation is poor in most symptomless endodontically treated teeth associated with a periapical lesion. In the case of retreatment of these teeth, the endodontic treatment need would then be calculated at 3.7%.     

Effectiveness of nickel-titanium files for preparing curved root canals

Abstract In this study, the effect of 2 different endodontic files on the final shape of curved root canals of extracted single rooted teeth were examined in the scanning electron microscope. The instruments tested were a newly designed nickel-titanium endodontic file and a conventional K-type file. The files were used with in and out linear movements with a circumferential motion starting with a size 15 file. Final preparation of the apical thirds of the canals was performed with a size 35 file. Shaping effectiveness of the tested instruments was evaluated in terms of respect for conservation of the apical constriction and the presence or absence of ledging. Our observations revealed that more centered and tapered preparations were obtained with the use of the nickel-titanium files than with the conventional K-type files.     

Endodontic treatment of mandibular incisors with two root canals: report of two cases

The root canal anatomy of mandibular incisors can present a number of variations, including multiple canals. Two case reports are presented to illustrate the serendipitous discovery and successful non-surgical endodontic management of complex canal systems in mandibular incisors. In both cases, all four mandibular incisors had two canals each.     

根管治疗期间急症的相关因素及防治

目的　探讨根管治疗期间急症(EIE)的临床相关因素及防治方法。方法　544颗患牙分为3组:①常规治疗组　392颗患牙按常规步骤行根管治疗;②口服药物组　91颗患牙在根管预备后给予患者地塞米松口服,余同常规治疗组;③开放引流组　61颗患牙初诊时预备根管后开放引流2~3 d,余同常规治疗组。记录各相关因素,统计各组EIE发生率和急性发作指数(FUI)。比较各因素与EIE关系以及不同实验组EIE的差异。结果　常规治疗组中,19·1%的患牙发生EIE;根管预备超出根尖孔的患牙EIE发生率和FUI值均显著高于根管预备长度欠和恰的患牙;患者的年龄、性别及患牙的牙位、病变程度与EIE发生率无明显关系。口服药物组较常规治疗组FUI值显著降低。开放引流组与常规治疗组比较,其EIE发生率和FUI值均无显著差异。结论　操作因素与EIE发作有显著关系,药物等预防措施可能减少EIE发作。     

Root canal treatment in general practice in Sudan

AIM: The aim of this study was to evaluate the practice and depth of knowledge of root canal treatment by dental practitioners in Khartoum, the capital city of Sudan, in order to improve the current status of endodontic therapy. METHODOLOGY: A questionnaire was posted to 55 registered dental practitioners. Completed questionnaires were analysed in term of simple summary statistics. RESULTS: A total of fifty-two (95%) practitioners responded. Eighty-five per cent of the respondents indicated that they performed root canal treatment for their patients. Of these, 84% included molars in their activity. Amongst those who carried out root canal treatment, only one practitioner used rubber dam for isolation, whilst the remainder used cotton wool rolls. The majority of respondents (80%) used hydrogen peroxide to irrigate canals during treatment. Three-quarters of practitioners used formocresol as an inter-appointment medicament. The stepback preparation technique was the method of choice for 98% of respondents. All practitioners used hand instruments to prepare root canals and all used gutta-percha for obturation; three-quarters of them used cold lateral condensation for all or some cases. The average number of radiographs routinely taken for root canal treatment was three. Only 73% used radiographs for measuring the working length. Ninety-five per cent of respondents indicated that they usually completed a root filling in three or more visits. Three-quarters of practitioners restored the teeth permanently immediately after the obturation and one-quarter preferred waiting for 1 or 2 weeks. CONCLUSIONS: In Sudan, there are no dental practices limited to endodontics and no postgraduate training programmes. This survey shows the importance of establishing higher specialist training or continuing dental education for practitioners to update their knowledge.