Periapical status and quality of root fillings and coronal restorations in an adult Spanish population

Deep-learning network for automated evaluation of root-canal filling radiographic quality

BACKGROUND

Deep-learning networks are promising techniques in dentistry. This study developed and validated a deep-learning network, You Only Look Once (YOLO) v5, for the automatic evaluation of root-canal filling quality on periapical radiographs.

METHODS

YOLOv5 was developed using 1,008 periapical radiographs (training set: 806, validation set: 101, testing set: 101) from one center and validated on an external data set of 500 periapical radiographs from another center. We compared the network's performance with that of inexperienced endodontist in terms of recall, precision, F1 scores, and Kappa values, using the results from specialists as the gold standard. We also compared the evaluation durations between the manual method and the network.

RESULTS

On the external test data set, the YOLOv5 network performed better than inexperienced endodontist in terms of overall comprehensive performance. The F1 index values of the network for correct and incorrect filling were 92.05% and 82.93%, respectively. The network outperformed the inexperienced endodontist in all tooth regions, especially in the more difficult-to-assess upper molar regions. Notably, the YOLOv5 network evaluated images 150-220 times faster than manual evaluation.

CONCLUSIONS

The YOLOv5 deep learning network provided clinicians with a new, relatively accurate and efficient auxiliary tool for assessing the radiological quality of root canal fillings, enhancing work efficiency with large sample sizes. However, its use should be complemented by clinical expertise for accurate evaluations.

Global trends in preclinical and clinical undergraduate endodontic education: A worldwide survey

This is a global study that evaluated the undergraduate endodontic curriculum in dental schools worldwide. An online questionnaire sent to faculty members involved in undergraduate endodontic teaching at 50 dental institutions across six continents. The questionnaire was a modified version of previously validated survey comprised of 46 questions in three sections on essential aspects of the didactic, preclinical (PT), clinical trainings (CT), and assessments in undergraduate endodontic programs. The response rate was 76%. 63.2% of schools have a separate preclinical course, with 65.8% having a dedicated clinical area. Traditional methods dominate, with 84.2% using phantom heads and 78.9% using natural extracted teeth. The student-to-staff ratio for clinical training ranges from 1:6 to 1:9, with most supervisors specializing in endodontics (76.3%). Lectures and practical sessions are the primary teaching methods. Non-surgical root canal treatment (RCT) is the most common procedure (94.7%), and the majority use stainless steel or rotary nickel-titanium files. Cold lateral compaction is the preferred obturation technique globally (81.6%), except in North America. Advanced technologies like magnifying systems and ultrasonic instruments are rarely used in training. The conclusion emphasizes the need for global standardization and adoption of modern techniques to enhance the quality of endodontic education and care.

Apical periodontitis in inflammatory bowel disease: a meta-analysis at patient and tooth level

Apical periodontitis (AP) is the local inflammation of periapical tissues originating from the dental pulp disease. Cumulative evidence suggests a link between oral and gastro-intestinal systems in both health and disease. In this context, the relationship between AP and inflammatory bowel diseases (IBDs) has not yet been elucidated. The aims of this systematic review and meta-analysis were to describe the prevalence of AP in patients with IBDs and evaluate the potential association between AP and IBDs. Electronic (Embase, PubMed, Scopus, Web of Science) and manual literature searches were conducted from inception to 31 October, 2023 (updated in August, 2024). Strict inclusion criteria were applied to identify observational and experimental clinical studies on AP in IBDs patients. The bias risk was assessed using the Joanna Briggs Institute critical appraisal tools and a biases' report selected from the Oxford Centre for Evidence Based Medicine Catalogue of Bias. A meta-analysis was performed to determine the pooled prevalence and risk of AP at individual and tooth level and the quality of evidence was assessed by the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. The search strategy identified 82 articles with 5 studies included (657 subjects, 7,142 teeth). The overall proportion of AP was 58% at patient level (95% CI = 37%-78%, I 2 = 95.3%) and 7% at tooth level (95% CI = 2%-15%; I 2 = 99.2%). AP was prevalent in IBDs subjects than in healthy controls, both at patient and tooth level. The pooled OR was 1.57 (95% CI = 1.04-2.35; P = 0.038; I 2 = 20%) at patient level, and 1.91 (95% CI = 1.16-3.15; P = 0.011; I 2 = 82%) at tooth level. A potential association between AP and IBDs is plausible, although the quality evidence was low to very low. Longitudinal and experimental studies should be conducted to better understand the relationship between these two conditions and explore any potential causative factors.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=411038, PROSPERO (CRD42023411038).

A multi-national survey-based evaluation of undergraduate/predoctoral endodontic education

AIM

To evaluate the current status of endodontic education and assessment at an undergraduate/predoctoral level in dental schools worldwide.

METHODOLOGY

The current survey comprised a 50-item online questionnaire related to undergraduate endodontic education. The project leaders emailed the survey's details to faculty members responsible for endodontic teaching at one dental school in every country to seek their willingness to participate in the survey. After the faculty members accepted, the survey details were sent to participants along with the survey link. Simple descriptive statistics were used to represent the data.

RESULTS

Amongst the 44 faculty members from different countries who agreed to participate, 36 completed the survey. Endodontic training starts in 50% of dental schools from the third year of the curriculum. Each dental school employs a diverse range of educational methods. During pre-clinical training, 19.4% of the participating dental schools used only natural teeth. Stainless-steel hand instruments, syringe irrigation with a needle, resin-based sealer and the cold lateral compaction technique are the most frequently used in pre-clinical and clinical training. A significant percentage of dental institutions necessitate that students treat a predetermined quantity of canals or teeth throughout their pre-clinical and clinical education. Dental institutions conduct formative, summative or a combination of the formative and summative throughout the clinical and pre-clinical phases of endodontic training.

CONCLUSIONS

According to the data collected from this survey, there are considerable variations in the curriculum for undergraduate/predoctoral endodontic programmes amongst the surveyed dental schools. Pre-clinical and clinical education should integrate a larger array of modern tools and procedures.

An Online Survey on the Current Trends in Root Canal Treatment

Root canal treatment in several regions of Saudi Arabia is commonly administered by general dental practitioners (GDPs) rather than specialized endodontists. The study aimed to compare the endodontic practices and preferences of general dental practitioners with those of endodontists and restorative specialists. A structured questionnaire including 23 questions focussing on fundamental principles and techniques used in contemporary root canal treatment was distributed online to 600 dentists who perform root canal treatments and are registered with the Saudi Dental Society (SDS). Data were gathered for basic demographic and professional details, practices, and preferences in endodontic materials and methods. The collected data were analyzed using SPSS version 21 (Armonk, NY: IBM Corp.). For selected variables, frequency distributions and 95% confidence interval for sample proportions were measured. Associations between categorical variables were examined using cross-tabulation, with statistical significance assessed by the chi-square test of homogeneity or Fisher's exact test when necessary. The survey, with a 59% response rate primarily from participants aged 24-34 years (94.1%) with one to five years of experience (90.4%), revealed that most GDPs referred root canal treatment (RCT) cases due to lack of skills (82.8%), performed restorability assessments (90.9%), preferred Cavit for tooth buildup (87%), consistently used rubber dam isolation (91.5%), treated mainly anterior teeth (91.2%) without magnification (87.9%), used electronic apex locators for working length determination (63.3%), favored stainless steel K files and single cone obturation, while specialists exhibited wider clinical experience, more frequent use of advanced techniques, and higher usage of intracanal medicaments (91.7%) and ethylenediaminetetraacetic acid (EDTA) as irrigant (70.8%). The study provides valuable insights into the endodontic preferences and practices of dentists in the Kingdom of Saudi Arabia, revealing significant differences between general dental practitioners and specialists. The findings highlight critical areas for improvement, such as the need for enhanced training in endodontic skills and better access to modern materials and equipment.

Effect of Orthodontic Treatment on the Outcomes of Endodontically Treated Teeth: A Cone-Beam Computed Tomography Analysis

INTRODUCTION

Often there is the need of moving endodontically treated teeth. Orthodontic movement may have no effect on the prognosis of teeth with root canal treatment (RCT). To verify this subject, we evaluated the effect of orthodontic movement on the prognosis of RCT teeth using cone-beam computed tomography (CBCT) and further explored the influence of orthodontic movement on the prognosis of RCT teeth with and without apical periodontitis (AP).

METHODS

This retrospective study was conducted by evaluating 169 RCT teeth of 100 patients who had undergone fixed orthodontic treatment. AP was assessed and classified using the CBCT periapical index. Univariate analysis of RCT outcome was performed for the total RCT group, RCT without AP group and RCT with AP group. Multivariate logistic regression was performed for the total RCT group and RCT without AP group, respectively, but not for the RCT with AP group. Variables related to the prognosis of RCT were included, such as age, gender, tooth position, RCT quality, coronal restoration quality, periodontal condition, orthodontic traction distance, and orthodontic rotation angle.

RESULTS

The orthodontic traction distance and rotation angle were not significantly correlated to the RCT outcomes, regardless of the presence of AP. Among the total RCT group, teeth with unqualified RCT (odds ratio = 3.42, P = .004) and inadequate coronal restoration (odds ratio = 4.40, P = .031) had a lower success rate. Of the 97 RCT teeth without AP, unqualified RCT was a risk factor for treatment failure (odds ratio = 3.55, P = .041). Of the 72 RCT teeth with AP, the univariate analysis showed that RCT quality were significantly related to the outcome (P = .042).

CONCLUSIONS

Orthodontic movement had no effect on the prognosis of RCT teeth regardless of the presence of AP.

A 22-year follow-up cross-sectional study on periapical health in relation to the quality of root canal treatment in a Belgian population

AIM

To investigate the prevalence of apical periodontitis (AP) and the technical standard of root canal treatment in a Belgian population, assess the association of different variables with periapical status, and compare the results to a similar study conducted 22 years previously.

METHODOLOGY

In this cross-sectional study, 614 panoramic radiographs of first-time adult attendees at the Dental School of the University Hospital of Ghent were examined. Recorded patient-level parameters included gender, age, number of teeth, number of root filled teeth, presence of any AP lesion, and number of implants. The following tooth-level data were collected: tooth presence, coronal status, quality of coronal restoration, post presence, type of root-filling material, length and density of root filling, root-end filling material, presence of AP, and adjacent implant. Multivariable multilevel binary logistic regression was used to explore the association between patient and tooth characteristics and AP prevalence. Risk differences and confidence intervals were calculated to compare the present with the previous study.

RESULTS

The prevalence of AP at patient and tooth level was 46.9% and 5.6%, respectively. Fifty-one per cent of the 614 patients had at least one root filled tooth, and 5.9% of the 14 655 teeth studied were root filled. AP was found in 45% of root filled teeth. Fifty-four per cent of the root-filled teeth were rated as inadequate. Multivariable multilevel logistic regression revealed that more teeth, more implants, fewer root-filled teeth, adequate density, adequate coronal restoration, and no caries reduced the likelihood of AP. There were no statistically significant differences between the two studies regarding the prevalence of root-filled teeth or AP and the technical quality of root canal treatment.

CONCLUSIONS

The prevalence of AP and the technical quality of root canal treatment in Belgium have not substantially changed over the last 22 years, despite the technological advancements and continuing education in the field.

Prevalence of apical periodontitis and quality of root canal treatment in an adult Kuwaiti sub-population: a cross-sectional study

Objectives

This cross-sectional study evaluated the prevalence of apical periodontitis (AP) and the technical quality of root canal fillings in an adult Kuwaiti subpopulation using cone-beam computed tomography (CBCT) images.

Materials and Methods

Two experienced examiners analyzed 250 CBCT images obtained from Kuwaiti patients aged 15-65 years who attended government dental specialist clinics between January 2019 and September 2020. The assessment followed the radiographic scoring criteria proposed by De Moor for periapical status and the technical quality of root canal filling. Chi-square and Fisher's exact tests were used for statistical analysis, with significance level set at p < 0.05.

Results

Among the 2,762 examined teeth, 191 (6.91%) exhibited radiographic signs of AP, and 176 (6.37%) had undergone root canal filling. AP prevalence in root canal-treated teeth was 32.38%, with a significant difference between males and females. Most of the endodontically treated teeth exhibited adequate root canal filling (71.5%).

Conclusions

The study demonstrated a comparable prevalence of AP and satisfactory execution of root canal treatment compared to similar studies in different countries.

Biological considerations of dental materials as orifice barriers for restoring root-filled teeth

There is ample published literature regarding the technical aspects of restoring root-filled teeth, but little concerning the biological impacts, consequences, and criteria for the selection of direct restorative materials following endodontic treatment. The provision of an effective coronal seal in addition to a sound root filling is known to be important in the prevention of root canal infection. This review seeks to explore the evidence concerning the selection of dental materials in the restoration of root-filled teeth, specifically with a close examination of the properties of commonly used materials as orifice barriers. © 2023 Australian Dental Association.

Incidence of Endodontic Failure Cases in the Department of Conservative Dentistry and Endodontics, DY Patil School of Dentistry, Navi Mumbai

INTRODUCTION

 Endodontic and restorative treatment goal is to restore occlusion and normal function of a tooth and provide stability to the dental arch. Root canal bacterial infection and apical periodontitis profoundly impact the management and outcome of endodontic treatments. The crucial goal of nonsurgical root canal therapy (NSRCT) is the mechanical removal of infected tissues and the chemical killing of bacteria. The present study assessed the outcomes and factors associated with the failure of primary endodontic treatment.

METHODS

 A total of 250 teeth from 219 patients (104 male and 146 female) were examined in the Conservative Dentistry and Endodontics department, who reported symptomatic root canal-treated teeth. Data through clinical examination and radiographic examination was recorded on a proforma designed for the study of each patient regarding endodontic failure.

RESULTS

 According to the type of tooth maximum number of teeth that were reported with failure are the molars (67.6%), followed by premolar (14.0%), incisor (12.8%), and lastly, canines (5.6%). Based on the location of affected teeth, the maximum teeth that presented with failed root canal treatment were from mandibular posteriors (51.2%), followed by maxillary posteriors (31.60%), maxillary anterior (13.2%), mandibular anterior (4.0%).

CONCLUSION

 Endodontic failures were mostly found in underfilled root canals and poorly sealed post-endodontic coronal restoration and strong association with peri-apical radiolucency.

Apical periodontitis and associated factors in a rural population of southern Brazil: a multilevel analysis

OBJECTIVES

This study aims to evaluate the association between apical periodontitis (AP) and sociodemographic/clinical factors in a probability sample of individuals living in a rural area of southern Brazilian.

MATERIALS AND METHODS

A cross-sectional study was conducted involving 584 non-edentulous adult individuals who had undergone a full-mouth radiographic survey. Periapical status was analysed using the periapical index (PAI). Endodontic status was evaluated considering the occurrence of voids in the filling material and the root filling length. Crown status was classified based on the presence of caries, restorations, and prosthetic crowns. Sociodemographic variables, frequency of dental care, and periodontal disease were also registered. The data were analysed using hierarchical multilevel Poisson regression analysis. The multilevel structure was composed of three models: sociodemographic variables, clinical variables, and clinical variables adjusted by sociodemographic variables (α = 5%).

RESULTS

The prevalence of AP in the sample was 60.45%. AP was significantly associated with age, skin colour, schooling, periodontal disease, and frequency of dental care (P < 0.005). Among the 10,396 teeth evaluated, 868 (8.35%) had AP, which was significantly associated with tooth group, dental arch, crown status, and endodontic treatment (P < 0.005).

CONCLUSIONS

The prevalence of AP was high in the population studied. An older age, black/brown skin colour, low level of schooling, infrequent dental care, severe periodontal disease, mandibular teeth, posterior teeth, inadequate crown status, and having undergone endodontic treatment were significantly associated with the outcome. Clinical relevance This study about a rural probability sample reinforces that AP is still a recurrent oral health problem.

How Is Endodontics Taught in Italy? A Survey of Italian Dental Schools

The aim of our study was to investigate how endodontics is taught in Italian universities. An online survey was conducted from August to December 2021. A comparison between courses led by full or associate professors (Group 1) versus courses led by other figures, such as researchers or temporary lecturers (Group 2), was made. A total of 28 out of 36 schools participated (78%). In most schools, endodontics is taught in the fifth year to 15-29 students. All schools planned pre-clinical endodontic training, and in 25/28 schools (89.3%), clinical endodontic training was also provided. The course programs varied among schools, and significantly more hours were allocated to teaching nonsurgical root canal treatment in Group 1 schools than in Group 2 schools. The average numbers of hours of preclinical and clinical training were 34.3 ± 23.6 and 84.1 ± 76.7, respectively. All schools used rotary NiTi files in their clinical training, and the vertical condensation of hot gutta-percha was the most frequently taught obturation technique. As expected, the scenario of endodontic education in Italian universities was variable and needs harmonization. Courses led by full or associate professors seem to be better structured.

Prevalence of root canal treatment worldwide: A systematic review and meta-analysis

BACKGROUND

The prevalence of root filled teeth (RFT) worldwide will inform about the amount of clinical activity of dentists dedicated to treat endodontic disease.

OBJECTIVES

To carry out a systematic review with meta-analysis answering the following question: What is the prevalence of RFT around the world? The percentage of people with at least one RFT was also investigated.

METHODS

A systematic review including population-based studies using the following databases: PubMed, EMBASE and Scielo. Studies related to prevalence of RFT were included. The outcome of interest of the study was the prevalence of RFT. The meta-analyses were calculated with the Open Meta Analyst software to determine the global prevalence of RFT. Subgroups analyses were performed comparing geographical distribution, radiographic method and year of the study (classified in 20th or 21th century). The prevalence of people with at least one RFT was also analysed.

RESULTS

Seventy-four population-based studies fulfilled the inclusion criteria. Twenty-eight, forty-four and two studies reported high, moderate and low risk of bias, respectively. No obvious publication bias was observed. Prevalence of RFT was estimated with 1 201 255 teeth and 32 162 patients. The calculated worldwide prevalence of RFT was 8.2% (95% CI = 7.3%-9.1%; p < .001). The global prevalence of people with at least one RFT was 55.7% (95% CI = 49.6%-61.8%; p < .001). In 20th century, the prevalence of RFT was 10.2% (95% CI = 7.9%-12.5%; p < .001), whereas in the 21st century the overall calculated prevalence of RFT was 7.5% (95% CI = 6.5%-8.6%; p < .001). Brazilian people (12%) and the European population (9.3%) showed the highest prevalence of RFT. In Europe, 59.6% (95% CI = 52.4%-66.8%) of people has at least one RFT.

CONCLUSIONS

This review showed that root canal treatment is a very common therapy throughout the world. More than half of the studied population have at least one RFT. A limitation of the present study is that most of the studies did not consider random sampling for population selection.

REGISTRATION

PROSPERO Systematic review registration number: (CRD42022329053).

Periapical and endodontic status of patients with inflammatory bowel disease: Age- and sex-matched case-control study

AIM

Crohn's disease (CD) and ulcerative colitis (UC) are two chronic recurrent inflammatory processes of the gastrointestinal tract, grouped under the name inflammatory bowel disease (IBD), causing clinical episodes of intestinal inflammation. The aim of this study was to investigate the possible association between IBD and the prevalence of apical periodontitis (AP) and root canal treatment.

METHODOLOGY

A case-control study design matched to age and sex was used. The study group (SG) included 28 patients with IBD (13 with CD, 15 with UC). Another 28 healthy subjects, without IBD and age- and sex-matched, were included in the control group (CG). Radiographic records were analysed and AP was diagnosed as radiolucent periapical lesions (RPLs), using the periapical index score. Student's t-test, χ2 test and multivariate logistic regression were used in the statistical analysis.

RESULTS

In the CG, only 17 subjects (61%) had at least one tooth with AP, whilst in the SG group they were 23 patients (82%; OR = 2.98; 95% CI = 0.87-10.87; p = .08). The number of subjects with one or more root filled teeth (RFT) in the CG was 14 (50%), whilst in the SG they were 22 (79%; OR = 3.67; 95% CI = 1.14-11.79; p = .026). At least one RFT with AP was evident in three subjects (10.7%) in the CG, whilst in the SG 15 patients (53.6%) showed RFT with AP (OR = 9.60; 95% CI = 2.35-39.35; p = .001). In the multivariate logistic regression analysis, only endodontic status was found to be associated with IBD (OR = 1.86; 95% CI = 1.24-2.80; p = .003).

CONCLUSION

IBD, UC and Crohn's disease are associated with higher prevalence of RFT and higher percentage of RFT with periapical lesions. Dentists should consider these findings when caring for IBD patients by monitoring the evolution of periapical lesions of endodontically treated teeth.

An Audit of the Technical Quality and Iatrogenic Errors of Root Canal Treatment by Undergraduate Dental Students at the University of Sharjah

OBJECTIVES

 The aim of this study was to determine the technical quality of root canal fillings and the presence of iatrogenic errors in the cases treated by undergraduate dental students using radiographic images.

MATERIALS AND METHODS

 This study included 480 root-filled teeth, which were evaluated using intraoral periapical radiographic images. The technical quality of obturation was assessed by observing the length, density, and taperness of the root filling. Ledges, apical transportation, fractured instruments, zipping, and root perforation were recorded as iatrogenic errors. Teeth were classified as acceptable if the technical parameters were adequate and there were no iatrogenic errors.

STATISTICAL ANALYSIS

 Data were statistically analyzed using Pearson's chi-squared test.

RESULTS

 The quality of root filling was acceptable in 183 of the 480 teeth. The rate of acceptable quality was higher for the teeth treated by 4th-year students (41.9%) than for those treated by 5th-year students (27.4%; p = 0.004). Length and taperness were adequate in more of the patients treated by the 4th-year students (p<0.05). There was a significant difference in the incidence of ledge formation and apical transportation in relation to the student's level (p<0.05).

CONCLUSIONS

 The technical quality of root fillings performed without iatrogenic errors by undergraduate dental students was declared acceptable in 38.1% of the assessed teeth. There was a noticeable difference in the quality of root canal treatment between the 4th- and 5th-year students.

CLINICAL RELEVANCE

 The findings demonstrate that periodic assessment of the technical quality of root filling performed by undergraduate dental students provides feedback on curriculum standards.

Is Coronal Restoration a Predictor of Posttreatment Apical Periodontitis?

Objectives  To investigate the posttreatment apical periodontitis (AP) in endodontically treated teeth through a multivariate approach and to analyze the relative importance of quality and type of coronal restoration as predictors of periapical disease.

Materials and Methods  The present study sample was drawn within 2-year period from the 1,072 consecutive patients older than 18 years, first time attending the Dental Clinic of the Clinical Hospital Center Rijeka, Croatia. A total of 1,350 endodontically treated teeth were included in the study. For each tooth, the periapical status, root filling quality, intracanal post, separated file presence, marginal bone loss, and quality and type of coronal restoration were recorded.

Statistical Analysis  Chi-square tests were used to analyze the variations in the periapical status, quality of root canal filling, and quality of coronal restoration in different tooth types. The effect of explanatory variables on periapical status was explored using univariate and multivariate logistic regression models. The outcome variable was set as the presence versus absence of AP in the tooth.

Results  Multivariate logistic regression analysis revealed statistically significant associations and increased risk for AP presence in molars (odds ratio [OR] = 2.15; p  < 0.001), teeth positioned in mandible (OR = 1.49; p  = 0.007), teeth with short length of root filling (OR = 4.08; p  < 0.001), overfilled teeth (OR = 2.99; p  = 0.001), and teeth with inadequate density of root filling (OR = 4.14; p  < 0.001). Considering variables related to coronal restoration, neither coronal restoration type nor quality was found to be predictive for posttreatment AP. Merely, the presence of intracanal post significantly increased the odds of AP presence (OR = 1.57; p  = 0.009).

Conclusion  The results of the present study did not indicate that type or quality of coronal restoration may be predictors of posttreatment AP. Periapical disease was significantly associated with molars, mandibular teeth, substandard quality of root fillings, and intracanal post presence.

Candida albicans Antimicrobial and Antibiofilm Activity of Novel Endodontic Solvents

Background: Candida albicans is the most prevalent fungi isolated in endodontic infections. In this study, the ability of C. albicans biofilm to tolerate the novel solvent mixtures methyl ethyl ketone (MEK)/tetrachloroethylene (TCE) and MEK/orange oil (OOil) sequentially to the standard irrigation of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic (EDTA) was evaluated. Methods: Biofilm cell cultures of C. albicans SC 5314 were treated sequentially with NaOCl and EDTA and exposed to MEK/TCE or MEK/OOil. The effect of the antimicrobial treatment was evaluated using the disk diffusion method for planktonic culture, and the enumeration of colony-forming units (CFUs) and scanning electron microscope (SEM) for biofilm cell culture. Results: C. albicans mature biofilm (24 h) was significantly reduced in biomass and cell viability after solvent mixtures’ exposure, compared with the previous NaOCl and EDTA treatments. MEK/OOil combination caused a total reduction of biofilm, while with MEK/TCE, there was a 3-log (CFU/cm2) reduction compared with the sequence NaOCl and EDTA, and a 4-log (CFU/cm2) reduction compared with the control. Conclusions: The additional exposure of a preformed 24 h C. albicans biofilm to novel solvent mixtures MEK/TCE and MEK/OOil caused a positive antibiofilm impact, overcoming the performance of the conventional endodontic irrigating protocol.

Effect of prosthetic restorations and root canal fillings on periapical health in a selected patient group

Aims To examine the effect of the quality of root canal fillings and prosthetic restorations on the frequency of apical periodontitis (AP).Methodology A total of 200 radiographs of 1,098 teeth with indirect restorations were selected. Each case was documented by age, sex, tooth location, tooth type, restoration type and presence of root canal treatment (RCT). Teeth were categorised as healthy or diseased considering periapical health. The quality of RCT and prosthetic restorations was categorised by radiographic and clinical examinations. Data were analysed using chi-squared test and logistic regression.Results Inadequate prosthetic restorations were found to be less healthy than the adequate ones. Statistical significance was found in teeth with RCT, which had a higher rate of AP (15.8%). Root-filled teeth categorised as inadequately treated (24.1%) were significantly unhealthier than the adequately root-filled teeth. Teeth with inadequate prosthetic restorations and RCT had an increase in AP risk of 6.41 and 20.74 times, respectively (p <0.05).Conclusions Results showed that AP risk was increased by both inadequate RCT and prosthetic restorations. Quality of RCT significantly affected periapical health more than the quality of prosthetic restorations. Not only radiographic but also clinical examination of restorations is required for successful evaluation.

Coronal Restoration as a Predictor of Periapical Disease in Non-Endodontically Treated Teeth

Objectives

To compare the frequency of apical periodontitis (AP) in non-endodontically treated teeth restored with full coverage crowns, amalgam and resin composite fillings, and to disclose the association of type and quality of coronal restoration with periapical disease.

Material and Methods

The cross-sectional study involved 597 subjects who attended the Dental Clinic of the Clinical Hospital Centre, Rijeka, Croatia for the first time. Data were collected by means of a clinical and radiological survey. The following data were recorded for all permanently restored non-endodontically treated teeth: the type, the quality of coronal restoration according to clinical and radiographic criteria for marginal integrity as well as the recurrent caries presence, periapical status and marginal bone loss. Chi-square tests were used to analyze the difference in periapical status regarding the type and the quality of restoration. The multivariate logistic regression analysis was used to assess the effect of explanatory tooth-specific variables on periapical status.

Results

There was no significant difference in the proportion of AP with regards to the type and material of adequate quality coronal restorations (χ²=5.000, P=0.082). The regression analysis revealed significant positive associations with outcome variable (AP) for crowns (OR=3.39; P<0.001), recurrent caries (OR=4.67; P<0.001) and premolar teeth (OR=1.73; P=0.002).

Conclusion

If the quality of restorations is adequate, there is no difference in the periapical status of non-endodontically treated teeth regarding the type and material of coronal restoration.

Prevalence of endodontic infection in patients with Crohn´s disease and ulcerative colitis

BACKGROUND

Previous studies have linked apical periodontitis (AP) to inflammatory bowel disease (IBD). The aim of this study was to compare the prevalence of AP and root canal treatment (RCT) in patients with ulcerative colitis (UC) and Crohn´s disease (CD).

MATERIAL AND METHODS

A cross-sectional study, including 28 patients with Crohn´s disease and 26 with ulcerative colitis, was conducted. AP was diagnosed as radiolucent periapical lesions (RPLs), using the periapical index score (PAI). Student's t test, 2 test and multivariate logistic regression were used in the statistical analysis.

RESULTS

Multivariate logistic regression run with age, gender, number of teeth, number of RFT, periodontal disease and the type of IBD as covariates, taking as dependent variable and outcome "periapical status" (0 = no tooth with RPL; 1 = at least one tooth with RPL), showed that both UC and CD patients had the prevalence apical periodontitis (OR = 1.03; C.I. 95% = 0.25 - 4.31; p = 0.97). The multivariate analysis, including all the above covariates, shows that both in UC and CD patients the prevalence of RCT was similar (OR = 0.76; C.I. 95% = 0.17 - 7.31; p = 0.73). Periapical status was significantly associated with endodontic status (OR = 42.72; C.I. 95% = 3.87 - 472.15; p = 0.002), regardless of IBD type.

CONCLUSIONS

The results of the present study show similar frequency of AP and RFT in both UC and CD patients. The type of IBD does not appear to affect the prevalence of radiographically detectable periapical lesions or the prevalence of root canal treatment.

Evaluation of undergraduate Endodontic teaching in dental schools within Spain

AIM

To evaluate the current situation of undergraduate endodontic teaching in Spanish dental schools.

METHODOLOGY

An online version, translated into Spanish, of a survey conducted in the UK (Int Endod J 52, 2019, 1077) was sent via email to the undergraduate endodontic programme leads in all 23 Spanish dental schools.

RESULTS

The response rate was 96%. In 95% of dental schools, endodontics is taught in the fourth year. Students treat simple root canal treatment cases in 100% of schools and only in 40% treat moderate cases. In 65% of schools, students are supervised by full-time professors who are specialists in Endodontics, significantly more frequently in private dental schools (P = 0.002). Spanish dental schools use both rotary and reciprocating instrumentation systems during endodontic training, with consistency on methods of working length determination, use of silicate-based endodontic cements, irrigating solutions, inter-visit medicaments and canal filling techniques. No type of magnification is used in 90% of dental schools, and only 25% use ultrasonic instruments. Private dental schools have a significantly better staff: student ratio during clinical practice (P = 0.041), spend significantly more hours in clinical training (P = 0.04) and have significantly greater number of clinical areas specifically dedicated to Endodontics (P = 0.010).

CONCLUSIONS

Undergraduate endodontic teaching in Spanish dental schools follows the key recommendations of the ESE Undergraduate Curriculum Guidelines (Int Endod J 46, 2013, 1105), being, in most respects, comparable to that carried out in the UK (Int Endod J 52, 2019, 1077). The use of magnification and ultrasonic instruments needs to be increased. Private schools reported better results than public schools in some of the variables that were analysed.

Comparison of Selected Anatomical and Treatment-related Diagnostic Parameters Estimated by Cone-Beam Computed Tomography and Digital Periapical Radiography in Teeth with Apical Periodontitis

Objectives

To compare selected anatomical and treatment-related diagnostic parameters estimated by cone-beam computed tomography and by digital periapical radiography in teeth with apical periodontitis, and to evaluate reliability of different examiners in interpretation of images obtained by both methods.

Material and Methods

Teeth with apical periodontitis were evaluated independently by 2 endodontists and 1 radiologist based on 128 cone-beam computed tomography (CBCT) and 162 digital periapical radiography (DPR) images. Anatomical (size, relation with root, location of periapical radiolucency) and treatment-related (canal obturation length, homogeneity, coronal seal) parameters were assessed. Fleiss kappa reflected inter-observer agreement while intra-examiner agreement was estimated by Cohen’s kappa. McNemar and McNemar-Bowker tests served for evaluation of differences between CBCT- and DPR-based estimates.

Results

Cohen’s kappa ranged from 0.62 to 1 for all examiners. Fleiss kappa values were nearly perfect for majority of parameters. Diagnostic discrepancy between methods was found for size of radiolucency that in 15 - 17% cases was larger, and in 25 - 28% smaller in DPR than in CBCT images. DPR revealed 20% of root canals scored as non-obturated while in CBCT - obturation present. Canal obturation was rated as homogenous by CBCT, while absent or non-homogenous by DPR, in 17 - 23%, and 11 - 14% of cases, respectively. Radiologist detected more root perforations in CBCT than in DPR images.

Conclusions

Good intra- and inter-examiner agreement for anatomical and treatment-related diagnostic parameters was achieved using cone-beam computed tomography and digital periapical radiography methods and demonstrated similar diagnostic capability, although variation regarding root perforations and canal obturation quality was observed.

Apical Periodontitis and Diabetes Mellitus Type 2: A Systematic Review and Meta-Analysis

Objective: Investigate if there is an association between apical periodontitis and diabetes mellitus. Material and methods: A bibliographic search was performed on Medline/PubMed, Scopus and Cochrane databases using the keywords apical periodontitis and diabetes mellitus. Published papers written in English and performed on animals or humans were included. Meta-analysis was performed using the OpenMeta (analyst) tool for the statistical analysis. The variables analyzed were the prevalence of Apical Periodontitis (AP) among teeth and patients with Diabetes Mellitus (DM). Results: Of the total studies found, only 21 met the inclusion criteria. Ten clinical studies on animals, ten studies on humans and a systematic review were included. Meta-analysis shows that the prevalence of teeth with apical periodontitis among patients with diabetes mellitus has an odds ratio of 1.166 corresponding to 507 teeth with AP + DM and 534 teeth with AP without DM. The prevalence of patients with AP and DM shows an odds ratio of 1.552 where 91 patients had AP + DM and 582 patients AP without DM. Conclusion: Scientific evidence suggests that there could be a common physiopathological factor between apical periodontitis and diabetes mellitus but more prospective studies are needed to investigate the association between these two diseases.

High Prevalence of Apical Periodontitis in Patients With Inflammatory Bowel Disease: An Age- and Gender- matched Case-control Study

BACKGROUND

Deep carious lesions cause pulpitis, pulpal necrosis and, finally, apical periodontitis (AP). Root canal treatment (RCT) is the treatment of choice for AP, changing the tooth into a root-filled tooth (RFT). Several studies have linked AP and RFT to systemic diseases. Likewise, previous studies have also found an association among inflammatory bowel disease (IBD) and periodontal disease. This study aims to analyze the frequency of AP and RCT in IBD patients and healthy control subjects.

METHODS

An age- and gender-matched case-control study design was used. The study group (SG) included 54 IBD patients (28 with Crohn´s disease, 26 with ulcerative colitis). Another 54 healthy subjects without IBD and age- and gender-matched were included in the control group (CG). The radiographic records were analyzed, and periapical radiolucencies were diagnosed as AP, using the periapical index (PAI). The statistical analysis was carried out using the Student t test, χ 2 test, and multivariate logistic regression.

RESULTS

The presence of 1 or more teeth with radiolucent periapical lesions (RPLs) was found in 19 patients (35.2%) in the study group and in 9 subjects (16.7%) in the control group (P = 0.03). No differences were found among the 2 groups neither in the amount of teeth with AP nor in the number of RFTs (P > 0.05). However, multivariate logistic regression analysis adjusting for number of teeth and number of RFTs showed that patients with IBD have RPLs with higher likelihood than control patients (odds ratio, 5.7; confidence interval 95%, 1.7-19.1; P = 0.0048).

CONCLUSIONS

Subjects with inflammatory bowel disease have higher prevalence of apical periodontitis. An oral health protocol should be established to address the higher prevalence of inflammatory oral processes.

Prevalence of apical periodontitis and its association with previous root canal treatment, root canal filling length and type of coronal restoration - a cross-sectional study

AIM

To analyse the prevalence of periapical lesions and their association with previous root canal treatment, root canal filling length and type of coronal restoration using in vivo cone-beam computed tomographic (CBCT) assessment.

METHODOLOGY

A global sample of 20 836 teeth, with a combined total of 27 046 roots, from 1160 patients, was analysed via CBCT assessment in eight health centres. Each tooth was evaluated by one out of five examiners after having performed a defined calibration procedure on the basis of 319 teeth. Intra- and inter-rater reliability tests were performed. Each tooth was classified according the tooth number, presence/absence of periapical lesions, presence/absence of previous root canal treatment, length of root canal filling (short, good or overfilling) and type of coronal restoration. The z-test for proportions was used to analyse differences between tooth subgroups, and an odds ratio was determined in order to analyse the association between treatment status and periapical lesions. A P < 0.05 was considered significant.

RESULTS

At a tooth level, the overall prevalence of periapical lesions in the sample was 10.4%. Maxillary teeth were associated with a significantly larger percentage of lesions (13.1%), whilst maxillary first molars had the greater proportion of lesions (21.2%). The prevalence of periapical lesions was significantly larger in root filled teeth (55.5%), short root canal fillings (72.7%) and in teeth restored with crowns (46.1%). At a root level, the mesiobuccal roots of both maxillary first molars had a tendency for a larger percentage of periapical lesions.

CONCLUSION

History of root canal treatment, root canal filling length and type of coronal restoration influenced the presence of periapical lesions. Molars were more commonly associated with periapical lesions on root filled teeth, particularly those with short root fillings and those with crowns.

Cone-beam computed tomography in the assessment of periapical lesions in endodontically treated teeth

Objective:

This study aimed to evaluate the relationship between the quality of the coronal restoration and the root canal filling on the periapical status of endodontically treated teeth using CBCT.

Materials and Methods:

CBCT data were obtained from the records of patients who deny any dental treatment in the 2 years prior to the CBCT examination. CBCT images (90 kVp and 7 mA, exposure time of 23 s, and a voxel size of 0.2 mm, with a field of view of 13 cm × 13 cm) of 1011 endodontically treated teeth were observed. A score was given to the quality of the root filling and the quality of the coronal restoration.

Statistical Analysis Used:

Data were statistically analyzed to correlate the periapical status with gender, dental group. and quality of endodontic treatment and restoration (Chi-square test with a significance level of P < 0.001).

Results:

Absence of periapical periodontitis was found in 54.9% of the cases. The periapical outcome was not related to gender or dental group (P > 0.05). A statistically significant factor (Chi-square test, P < 0.0001) resulted when different qualities of sealing were compared.

Conclusions:

CBCT showed that high-quality root canal treatments followed by an adequate coronal sealing restoration avoid the presence of periapical periodontitis in time.

The "Plan" phase of a Deming cycle: Measurement of quality and outcome of root canal treatments in a university hospital

INTRODUCTION

In many countries, dental students are taught in private or university hospitals where they treat patients under the supervision of teachers. Assessing the quality of root canal treatments (RCT) would provide information about the quality of care patients receive when treated by students.

METHODS

This study describes the six-step "Plan" phase of a Plan-Do-Check-Act (PDCA) cycle that identifies and analyses clinical practices in endodontics in a university dental hospital service.

RESULTS

Step 3 reported that the proportion of RCTs of adequate quality reached 57.1% and this proportion was significantly decreased when specific indicators for treatment difficulties were present. The proportion of successful RCTs after 1 year was 65.6%, and its variation was influenced by the preoperative periapical status rather than the quality of RCTs. The consensual meeting in Step 6 proposed to introduce three new procedures for the further Do, Check and Act phases of the PDCA cycle.

CONCLUSION

This study encourages systematic evaluation of RCTs and provides the first step of the methodology that can be reproduced in private and hospital practices where students are asked to treat patients.

Clinical audit training improves undergraduates' performance in root canal therapy

AIM

To evaluate the effectiveness of clinical audit-feedback cycle as an educational tool in improving the technical quality of root canal therapy (RCT) and compliance with record keeping performed by dental undergraduates.

METHODS

Clinical audit learning was introduced in Year 3 of a 5-year curriculum for dental undergraduates. During classroom activities, students were briefed on clinical audit, selected their audit topics in groups of 5 or 6 students, and prepared and presented their audit protocols. One chosen topic was RCT, in which 3 different cohorts of Year 3 students conducted retrospective audits of patients' records in 2012, 2014 and 2015 for their compliance with recommended record keeping criteria and their performance in RCT. Students were trained by and calibrated against an endodontist (κ ≥ 0.8). After each audit, the findings were reported in class, and recommendations were made for improvement in performance of RCT and record keeping. Students' compliance with published guidelines was presented and their RCT performances in each year were compared using the chi-square test.

RESULTS

Overall compliance with of record keeping guidelines was 44.1% in 2012, 79.6% in 2014 and 94.6% in 2015 (P = .001). In the 2012 audit, acceptable extension, condensation and the absence of mishap were observed in 72.4, 75.7% and 91.5%; in the 2014 audit, 95.1%, 64.8% and 51.4%; and in 2015 audit, 96.4%, 82.1% and 92.8% of cases, respectively. In 2015, 76.8% of root canal fillings met all 3 technical quality criteria when compared to 48.6% in 2014 and 44.7% in 2012 (P = .001).

CONCLUSION

Clinical audit-feedback cycle is an effective educational tool for improving dental undergraduates' compliance with record keeping and performance in the technical quality of RCT.

Changes in periapical status, quality of root fillings and estimated endodontic treatment need in a similar urban German population 20 years later

OBJECTIVES

The study aimed at assessing, as primary objective, the periapical status and quality of root fillings, and, as secondary objective, the endodontic treatment need of a German urban population in a cross-sectional study 20 years after the first one.

MATERIALS AND METHODS

Clinical and radiographic data of 353 patients were evaluated. Descriptive and regression analyses were performed and the endodontic treatment need was calculated. Results were compared with data from the year 1993.

RESULTS

A total of 9269 teeth were examined (26.2 teeth per patient; 1993, 24.4), of which 337 teeth were root filled (3.6%; 1993, 2.7%). Prevalence of apical periodontitis in root-filled teeth was 34% (1993, 61%). Quality of root fillings was adequate in 117 cases (35%; 1993, 14%). Minimum endodontic treatment need was estimated with 1.6% (1993, 2.3%), including teeth with clinical symptoms. Considering symptomless teeth with apical periodontitis and poor quality of root filling, the treatment need was 2.9% (1993, 3.7%). Regression analysis identified quality of root filling as a significant factor for periapical health (p = 0.01, odds ratio 3.4×, 95% CI 1.9-6.3×), likewise the type of instrumentation. Teeth treated with rotary files had a significantly better outcome (p = 0.02, odds ratio 2.0×, 95% CI 1.1-3.7×).

CONCLUSIONS

Quality of root fillings and the periapical status have improved over the last 20 years in Germany. However, there is still a need for an increase in quality of root canal treatment.

Periapical Status and Quality of Root Canal Fillings in a Moroccan Subpopulation

AIM

The aim of the study was to assess the prevalence of apical periodontitis (AP) and quality of root canal fillings in an adult Moroccan subpopulation.

METHODS

In the study 508 patients were included, attending the Conservative Dentistry Clinic at the Faculty of Dentistry of Casablanca. 508 panoramic and 709 periapical radiographs were observed. The periapical status of all teeth (with the exception of third molars) was examined according to Ørstavik's periapical index. The statistical analysis was performed with the software Epi Info Version 6.04dfr, April 2001.

RESULTS

A total of 12719 teeth were examined. 45.3% of patients had apical periodontitis. 4.2% of teeth were treated endodontically and 70.4% of these treatments were inadequate. 91,5% with inadequate endodontic treatment presented apical periodontitis, while only 8,2% with adequate endodontic treatment had apical periodontitis. The lower molars and the upper premolars were the most affected teeth. The presence of apical periodontitis was correlated significantly with insufficient root canal fillings (p < 0.05).

CONCLUSIONS

The present study found a high prevalence of apical periodontitis in this Moroccan population. Inadequate root canal fillings were associated with an increased prevalence of apical periodontitis.

Association of Quality of Coronal Filling with the Outcome of Endodontic Treatment: A Follow-up Study

The aim of this study was to assess the effect of the quality of the coronal restoration and the root filling on the success of endodontic treatment. Patients treated at Kuwait University Dental Clinics (KUDC) from 2003 to 2014 were contacted by telephone calls. Demographic data and clinical records of patients, including age, gender, the tooth number, and medical history were recorded. Each patient received clinical examination for all teeth, including assessment of the coronal filling (type, quality), root- and/or coronal fracture, and the periodontal condition around the tooth (e.g., probing depth, gingival recession); percussion and mobility tests. A periapical radiograph of the endodontic treated tooth was taken to determine the health of the periapical tissues using the periapical index. The quality of the root filling was assessed by length and density of the root filling. The mean follow-up period was 4.8 years. The overall success rate of endodontic treatment was 86%; teeth without any initial periapical lesion had a success of 93%, whereas those with such lesion had a success rate of 80%. Periapical healing was not significantly associated with either the length of root filling (p = 0.40) or the density of root filling (p = 0.099), but was statistically significantly associated with the presence of coronal filling defects (p = 0.001). This study demonstrated that inadequate coronal filling but not the quality of root filling was associated with a higher prevalence of periapical lesions.

Restoration of the root canal treated tooth

When considering endodontically treated teeth, the quality of the restoration is important from the outset. It sheds light into possible causes of pulp necrosis or failure of endodontic treatment and influences the outcome of future endodontic treatment. A tooth undergoing endodontic treatment requires an effective coronal seal during and following completion of endodontic treatment. This paper discusses, using the available literature, the maintenance of optimal coronal seal and coronal integrity during and after root canal treatment.

Preclinical endodontic teaching. A survey of Saudi dental schools

Objectives:

To provide an overview of the general curricula in preclinical endodontic training from 6 established dental schools in Saudi Arabia.

Methods:

This study was conducted in January 2014 including only schools that had more than 2 groups of student graduates prior to the study. We included 2 dental schools from the Central region, one from Qassim region, one from the Makkah region (west), one from Abha region (south west), and one from the eastern region. An internet-based questionnaire was sent to the course directors of preclinical endodontics department of the 6 schools. The survey comprised 20 questions that examined various aspects of preclinical endodontics.

Results:

It was demonstrated that a significant number of faculty members had Doctor of Philosophy (PhD) degrees (n=21), Master’s degrees (n=15), and Saudi board certifications (n=8). We determined that the faculty to student ratio varied from 2:1 to 8: 1 among the colleges. The participating dental schools were found to teach the Step Back, as well as the Step Down techniques for root canal preparation. Five of the 6 schools implemented the use of nickel titanium rotary instruments. All dental schools predominantly used radiographs as the means of the working length determination.

Conclusion:

The curriculum for preclinical endodontics in Saudi Arabia is comparable to that followed in most European countries. A more comprehensive survey is needed that would involve more schools to formulate generalized guidelines for preclinical endodontic training in Saudi Arabia.

Status of Endodontic Treatment and the Correlations to the Quality of Root Canal Filling and Coronal Restoration

INTRODUCTION

This cross-sectional study evaluated the prevalence and quality of root canal treatment in 1,977 digital radiological files.

MATERIALS AND METHODS

Data were statistically analyzed using descriptive analysis, and the chi-square test was performed with a 5% significance level.

RESULTS

The mean age of the study population was 34.9 years. The endodontic treatment frequency was 6.14%, significantly higher in premolars. Adequate endodontic treatment was observed in 39.7% of analyzed cases. Molars were significantly more frequent with regard to inadequate filling quality. In 47.6% of cases, the filling's apical limit was classified as adequate, and there was a higher incidence of molars that were inadequate. Restorations were classified as adequate in 79.0% of cases, and molars were responsible for the highest frequency of inadequate restorations. The frequency of teeth with endodontic treatment that showed no periapical changes was 47.7%. There was no significant difference in the presence of periapical change according to gender. An increased presence of periapical change was observed with increasing age. The periapical lesions were observed in 45% of cases and related to inadequate filling quality. The apical limit was considered inadequate and related to periapical changes in 42% of cases. Periapical changes were present in 52% of cases, regardless of the quality of the filling and apical limit. Such changes were present in 42% of cases with adequate coronal restoration.

CONCLUSION

It can be concluded that apical periodontitis (AP) is associated with the quality of endodontic treatment. The coronal restoration affects significantly the success rate of endodontic treatment.

CLINICAL SIGNIFICANCE

The quality of the root filling and coronal restoration is closely related to periapical health.

Apical periodontitis and the technical quality of root canal treatment in an adult sub-population in London

AIM

To assess the prevalence of apical periodontitis (AP) and the technical quality of root canal treatment in an adult sub-population in London.

METHODOLOGY

Panoramic radiographs of 136 patients who attended a dental hospital were collected. The periapical health of teeth present was assessed radiographically and the presence or absence of AP noted. The technical quality of the root canal treatment was scored as adequate or inadequate, based on the European Society of Endodontology (2006) guidelines.

RESULTS

A total of 3,396 teeth were assessed; AP was detected in 4.1% of the teeth. Forty-nine percent of patients had at least one tooth with radiographic evidence of AP. The percentage of root filled teeth with AP was 38.3%. AP was significantly more frequently found in root treated, compared with non-root treated, teeth (p <0.001). In 44.3% of the cases, the technical quality of the root canal filling was inadequate. AP was detected in 14% of adequately, compared with 68.6% of inadequately, root filled teeth. There is a significant negative correlation between the technical quality of root canal treatment and the presence of AP (p <0.001).

CONCLUSIONS

There was a high prevalence of AP and poor technical quality root canal treatment; a strong association between AP and root filled teeth, and between the periapical health and the technical quality of the root canal treatment. The results are consistent with previous studies using similar methodology and re-confirmed that high technical quality root canal treatment is crucial to ensure a favourable treatment outcome.

Failure of endodontic treatment: The usual suspects

Inappropriate mechanical debridement, persistence of bacteria in the canals and apex, poor obturation quality, over and under extension of the root canal filling, and coronal leakage are some of the commonly attributable causes of failure. Despite the high success rate of endodontic treatment, failures do occur in a large number of cases and most of the times can be attributed to the already stated causes. With an ever increasing number of endodontic treatments being done each day, it has become imperative to avoid or minimize the most fundamental of reasons leading to endodontic failure. This paper reviews the most common causes of endodontic failure along with radiographic examples.

Microscopic assessment of the sealing ability of three endodontic filling techniques

Background

Several techniques have been proposed for root canal filling. New rotary files, with non-standardized taper, are appearing, so, points adapted to the taper of the last instrument used to prepare the canal can help in the obturation process. The aim of this study is to assess the sealing ability of different root canal filling techniques.

Material and Methods

Root canals from 30 teeth were shaped with Mtwo and divided in three groups; A, standard lateral condensation with size 35 and 20 gutta-percha points; B, standard lateral condensation and injected gutta-percha; C, single gutta-percha point (standardized 35 Mtwo), continuous wave technique and injected gutta-percha. Root surfaces were covered with nail varnish, except for the apical 2 mm, and submerged in a NO3Ag2 solution; apical stain penetration was measured in mm. Data were compared using the Kruskal-Wallis test with a 90% confidence interval.

Results

A and B groups showed stain leakage in the 90% of the cases, whereas it was of 80% for group C. Stain leakage intervals were 1-5 mm for groups A and B and 1-3 mm for group C. There were no statistically significant differences between the three studied groups (p>.05).

Conclusions

All the analyzed root canal filling techniques showed some apical stain leakage, without significant differences among them.

Key words:Gutta-percha filling, microleakage, single cone, injected gutta-percha, warm gutta-percha.