Factors Associated with Extraction following Root Canal Filling in Adults.

Essentially, root fillings are performed to preserve natural teeth. Over time, however, some root-filled teeth will inevitably be extracted. The aim of this historical prospective cohort study in the adult Swedish population was to identify factors associated with extractions within 5 y of registration of a root filling. The cohort consisted of all those whose root fillings had been reported to the tax-funded Swedish Social Insurance Agency (SSIA) in 2009. Demographic data on the individuals registered with a root filling (sex, age, country of birth, disposable income, educational level, and marital status) were received from Statistics Sweden or the SSIA. Dental care setting, tooth type, and any registration of subsequent restorations within 6 mo were received from the SSIA. Multivariable regression analysis was used, and P < 0.05 was considered statistically significant. In total, 216,764 individuals had been registered with at least 1 root filling. Individuals (n = 824) without complete data were excluded from the analyses. After 5 y, 9.3% of the root-filled teeth had been registered as extracted. Logistic regression analysis found significant associations for all variables except country of birth, disposable income, and educational level. The highest odds ratios for extractions were associated with the type of restoration: teeth with no registration of any restoration and teeth with a direct restoration combined with a post were 3 times more likely to undergo extraction than teeth restored with an indirect restoration combined with a post and core. Overall, high odds ratios for extractions were associated with any type of composite restoration, including composite fillings and crowns combined with or without any post. In summary, after root filling in the Swedish adult population, several individual- and tooth-specific variables were associated with extraction. The reasons for the extractions remain to be studied further.

A macroscopic and histological analysis of radiographically well-defined deep and extremely deep carious lesions: carious lesion characteristics as indicators of the level of bacterial penetration and pulp response.

AIM: To investigate the relationship between radiographically and macroscopically well-defined carious lesions and the dentine-pulp complex with regard to: (i) level of bacterial penetration; (ii) inflammatory status including the presence of hyperplastic pulp stroma; and (iii) formation of hard and/or ectopic connective tissue. METHODOLOGY: The material comprised 68 untreated cavitated permanent teeth divided into well-defined radiographic categories based on the lesion penetration depth: (i) deep lesions ( ≥3/4 of the dentine thickness with a radio-dense zone separating the lesion from the pulp) and (ii) extremely deep lesions (the carious lesion penetrated the entire thickness of the dentine, without a radio-dense zone). After extraction, the teeth were processed for histology. The material was scored with regard to coronal breakdown, macroscopic variables describing caries activity and histological variables describing the dentine-pulp complex (bacteria, inflammatory infiltrate, partial pulp necrosis, hyperplastic changes and hard tissue/ectopic presence of connective tissue). Interrater agreement was assessed using Cohen's kappa. Associations between variables were assessed using Pearson's chi-squared or Fisher's exact test. The effect size was reported by odds ratio (OR) and associated 95% confidence interval (CI). Level of significance was set to 5%. RESULTS: There were significant associations between a closed environment (1-2 surfaces involved) and the presence of biofilm, retrograde demineralization and light-coloured demineralized dentine. Whereas radiographically defined deep lesions tended to have bacteria only in the primary dentine (P < 0.001, OR = 20.55, 95% CI [4.44, 107.89]), extremely deep carious lesions tended to have bacteria in contact with the pulpal tissue (P = 0.007, OR = 6.84, 95% CI [2.00, 62.83]), presence of an inflammatory infiltrate (Fisher's exact; P < 0.001) and partial pulp necrosis. Hyperplastic pulps were seen only in extremely deep lesions. CONCLUSIONS: Unlike deep lesions, extremely deep carious lesions were often associated with severe pulp inflammation and infection. A radiographic threshold between deep and extremely deep lesions is suggested as indicator of the bacterial penetration level and the severity of the pulpal response prior to intervention.

PRIRATE 2020 guidelines for reporting randomized trials in Endodontics: explanation and elaboration.

Well-designed and properly conducted randomized clinical trials provide a true estimate of the effects of interventions and are acknowledged as the gold standard in terms of clinical study design. However, the quality of randomized clinical trials published in the field of Endodontics is suboptimal. The Preferred Reporting Items for RAndomized Trials in Endodontics (PRIRATE) 2020 guidelines were developed exclusively for Endodontics by integrating and adapting the CONsolidated Standards of Reporting Trials (CONSORT) statement and Clinical and Laboratory Images in Publications (CLIP) principles, through an accepted and well-documented consensus process. Full implementation of the PRIRATE 2020 guidelines will minimize potential sources of bias and thus enhance the standard of manuscripts submitted for publication, which will ultimately improve the reporting of randomized clinical trials in Endodontics. The aim of this document is to provide an explanation for each item in the PRIRATE 2020 checklist and flowchart with examples from the literature in order to help authors understand their rationale and significance. A link to this PRIRATE 2020 explanation and elaboration document is available on the Preferred Reporting Items for study Designs in Endodontology (PRIDE) website at http://www.pride-endodonticguidelines.org/prirate/.

PRIRATE 2020 guidelines for reporting randomized trials in Endodontics: a consensus-based development.

In evidence-based health care, randomized clinical trials provide the most accurate and reliable information on the effectiveness of an intervention. This project aimed to develop reporting guidelines, exclusively for randomized clinical trials in the dental specialty of Endodontology, using a well-documented, validated consensus-based methodology. The guidelines have been named Preferred Reporting Items for RAndomized Trials in Endodontics (PRIRATE) 2020. A total of eight individuals (PD, VN, HD, LB, TK, JJ, EP and SP), including the project leaders (PD and VN) formed a steering committee. The committee developed a checklist based on the items in the Consolidated Standards of Reporting Trials (CONSORT) guidelines and Clinical and Laboratory Images in Publications (CLIP) principles. A PRIRATE Delphi Group (PDG) and PRIRATE Face-to-Face Meeting group (PFMG) were also formed. Thirty PDG members participated in the online Delphi process and achieved consensus on the checklist items and flowchart that make up the PRIRATE guidelines. The guidelines were discussed at a meeting of the PFMG at the 19th European Society of Endodontology (ESE) Biennial congress, held on 13 September 2019 in Vienna, Austria. A total of 21 individuals from across the globe and four steering committee members (PD, VN, HD and LB) attended the meeting. As a consequence of the discussions, the guidelines were modified and then piloted by several authors whilst writing a manuscript. The PRIRATE 2020 guidelines contain a checklist consisting of 11 sections and 58 individual items as well as a flowchart, considered essential for authors to include when writing manuscripts for randomized clinical trials in Endodontics.

Management of deep caries and the exposed pulp.

Caries prevalence remains high throughout the world, with the burden of disease increasingly affecting older and socially disadvantaged groups in Western cultures. If left untreated, caries will advance through dentine stimulating pulpitis and eventually pulp infection and necrosis; however, if conservatively managed, pulpal recovery occurs even in deep carious lesions. Traditionally, deep caries management was destructive with nonselective (complete) removal of all carious dentine; however, the promotion of minimally invasive biologically based treatment strategies has been advocated for selective (partial) caries removal and a reduced risk of pulp exposure. Selective caries removal strategies can be one-visit as indirect pulp treatment or two-visit using a stepwise approach. Management strategies for the treatment of the cariously exposed pulp are also shifting with avoidance of pulpectomy and the re-emergence of vital pulp treatment (VPT) techniques such as partial and complete pulpotomy. These changes stem from an improved understanding of the pulp-dentine complex's defensive and reparative response to irritation, with harnessing the release of bioactive dentine matrix components and careful handling of the damaged tissue considered critical. Notably, the development of new pulp capping materials such as mineral trioxide aggregate, which although not an ideal material, has resulted in more predictable treatments from both a histological and a clinical perspective. Unfortunately, the changes in management are only supported by relatively weak evidence with case series, cohort studies and preliminary studies containing low patient numbers forming the bulk of the evidence. As a result, critical questions related to the superiority of one caries removal technique over another, the best pulp capping biomaterial or whether pulp exposure is a negative prognostic factor remain unanswered. There is an urgent need to promote minimally invasive treatment strategies in Operative Dentistry and Endodontology; however, the development of accurate diagnostic tools, evidence-based management strategies and education in management of the exposed pulp are critical in the future.

Preferred Reporting Items for RAndomized Trials in Endodontics (PRIRATE) guidelines: a development protocol.

Randomized clinical trials are acknowledged as the most appropriate methodology for demonstrating the efficacy or effectiveness of one intervention as opposed to another and thus play a major role in clinical decision-making. However, it is recognized that despite the existence of various guidelines, for example, the Consolidated Standards for Reporting Trials (CONSORT) statement, the quality of manuscripts describing randomized trials is often suboptimal. The current project aims to develop and disseminate new guidelines, Preferred Reporting Items for RAndomized Trials in Endodontics (PRIRATE), to improve the planning and reporting quality of randomized trials in the field of Endodontics. The project leads (VN, PD) designed a robust process to develop the PRIRATE guidelines. At first, a steering committee of eight members, including the project leads, was formed. Thereafter, a five-stage consensus process will be followed: initial steps, pre-meeting activities, face-to-face consensus meeting, post-meeting activities and post-publication activities. The steering committee will develop the first draft of the PRIRATE guidelines by identifying relevant and important items from various sources including the CONSORT guidelines and the Clinical and Laboratory Images in Publications (CLIP) principles. This will be followed by the establishment of a PRIRATE Delphi Group (PDG) consisting of 30 members. The individual items of the first draft of the PRIRATE guidelines developed by the steering committee will be evaluated and scored on a 9-point Likert scale by the PDG members. Items with a score of seven and above by more than 70% of PDG members will be included in the second draft of the guidelines, and the Delphi process will be repeated until each item fulfils the set conditions. After obtaining consensus from the PDG, the PRIRATE guidelines will be discussed by 20 selected individuals within a PRIRATE Face-to-face Consensus Meeting Group (PFCMG) to arrive at a final consensus. The final PRIRATE guidelines will be accompanied with an explanation and elaboration document developed by the steering committee and approved by six members, three from the PDG and three from the PFCMG. The PRIRATE guidelines will be published in journals and actively disseminated to educational institutions, national and international academic societies and presented at scientific meetings. The steering committee will periodically revise and update the PRIRATE guidelines based on feedback from stakeholders.

European Society of Endodontology position statement: Management of deep caries and the exposed pulp.

This position statement on the management of deep caries and the exposed pulp represents the consensus of an expert committee, convened by the European Society of Endodontology (ESE). Preserving the pulp in a healthy state with sustained vitality, preventing apical periodontitis and developing minimally invasive biologically based therapies are key themes within contemporary clinical endodontics. The aim of this statement was to summarize current best evidence on the diagnosis and classification of deep caries and caries-induced pulpal disease, as well as indicating appropriate clinical management strategies for avoiding and treating pulp exposure in permanent teeth with deep or extremely deep caries. In presenting these findings, areas of controversy, low-quality evidence and uncertainties are highlighted, prior to recommendations for each area of interest. A recently published review article provides more detailed information and was the basis for this position statement (Bjørndal et al. 2019, International Endodontic Journal, doi:10.1111/iej.13128). The intention of this position statement is to provide the practitioner with relevant clinical guidance in this rapidly developing area. An update will be provided within 5 years as further evidence emerges.

Guided root canal preparation using cone beam computed tomography and optical surface scans - an observational study of pulp space obliteration and drill path depth in 50 patients.

AIM: To report the precision of guided access cavity preparations in relation to demographical and dental variables in 50 patients. METHODOLOGY: This observational study was carried out during the period 2014-2017. The patients were consecutive referrals to a private endodontic practice. The inclusion criteria were as follows: (i) pulp space obliteration associated with signs of apical periodontitis (PAI score >3 or sensitive to percussion, (ii) teeth with pulp space obliteration in need of a post, where the referring dentist had attempted or failed to negotiate the obliterated root canal (and it was not possible to negotiate using the operating microscope within a reasonable time frame) and (iii) a surgical intervention was not justified. A published methodology for guided endodontics was used. Measures on demographical and previous dental history were analysed and related to drill path precision, being evaluated on radiographs as optimal (centre of the root canal) or acceptable (peripheral/tangential). The chi-square test was used for analyses of correlation between predictor variables and binary logistic regression analysis using backward elimination with degree of obliteration, guided access cavity preparation depth and precision as dependent variables. Significance level was 0.05. RESULTS: Thirty-one female (median age 65 year) and 19 males (median age 69 year) were enrolled. Overall, 88% (n = 44) of the teeth had pulp space obliteration associated with signs of apical periodontitis, whereas the remaining teeth were in need of a post. The pulp space obliterations were longer in maxillary compared with mandibular teeth (P = 0.024). The performance of the drill path in mandibular teeth versus maxillary teeth resulted in a significantly greater number of optimal precision scores (P = 0.033), and when a previous attempt at access and canal negotiation had occurred versus no attempt (P = 0.009). Even in cases with the worst outcome, the technique was still successful clinically. CONCLUSIONS: The clinical implementation of guided root canal treatment in fifty serial cases of single-rooted teeth with pulp space obliteration was associated with a precision that in all cases led to the location and negotiation of the root canal and completion of the treatment.

Demographic factors in Swedish adults undergoing root filling and subsequent extraction of a maxillary first molar: a comparative study.

AIM: To study the demographics of Swedish adults who had received a root filling, followed by extraction during the following 5-6 years in comparison with subjects who had undergone a corresponding root filling with an uneventful outcome. METHODOLOGY: The root filled maxillary first molar was chosen as the comparison model. The Swedish Social Insurance Agency provided data on all teeth reported as root filled in Sweden during 2009. A comparison group, equally large as the study group, was constructed by randomly selecting subjects with root filled maxillary first molars, which had not subsequently been extracted, that is, an uneventful outcome. Demographic data on the subjects were obtained from Statistics Sweden: country of birth, disposable income, educational level, age, civil status and gender. Chi-square, t-tests and logistic regression were used for statistical analyses. RESULTS: In the year 2009, 36 139 maxillary first molar teeth were reported to have been root filled, 4362 (12.1%) of which were then recorded as extracted during the following 5-6 year period. Only minor intergroup differences were noted: 86.5% of the study group were Swedish-born, compared with 84.4% of the comparison group (P = 0.007). Women comprised 53.2% of the study group and 50.5% (P = 0.01) of the comparison group. There was an association between extractions and gender as well as age; men had a lower odds ratio (OR) for extraction OR, 0.87; confidence interval (CI), 0.80-0.95. For every additional year, the chance for extraction was higher OR, 1.01; CI, 1.01-1.01. No other significant differences were detected. CONCLUSIONS: There was only little or no demographic differences between the study group, comprising Swedish adults who had undergone root filling of one of their maxillary first molars in 2009 and subsequent extraction during the following 5-6 years, and the comparison group, with uneventful outcomes after a corresponding root filling.

Randomized Clinical Trials on Deep Carious Lesions: 5-Year Follow-up.

Deep caries presents a dilemma in terms of which treatment that will render an optimal prognosis by maintaining pulp vitality with absence of apical pathology. Previously, 2 randomized clinical trials were performed testing the short-term effects of stepwise carious tissue removal versus nonselective carious removal to hard dentin with or without pulp exposure. The aim of this article was to report the 5-y outcome on these previously treated patients having radiographically well-defined carious lesions extending into the pulpal quarter of the dentin but with a well-defined radiodense zone between the carious lesion and the pulp. In this long-term study, 239 of 314 (76.2%) patients were analyzed. The stepwise removal group had a significantly higher proportion of success (60.2%) at 5-y follow-up compared with the nonselective carious removal to hard dentin group (46.3%) ( P = 0.031) when pulp exposures per se were included as failures. Pulp exposure rate was significantly lower in the stepwise carious removal group (21.2% vs. 35.5%; P = 0.014). Irrespective of pulp exposure status, the difference (13.3%) was still significant when sustained pulp vitality without apical radiolucency and unbearable pain was considered (95% confidence interval, 3.1-26.3, P = 0.045). After pulp exposure, only 9% ( n = 4) of the analyzed patients were assessed as successful, indicating that the prognosis is highly dubious following conventional pulp-capping procedures (direct pulp capping or partial pulpotomy) in deep carious lesions in adults. In conclusion, the stepwise carious removal group had a significantly higher proportion of pulps with sustained vitality without apical radiolucency versus nonselective carious removal of deep carious lesions in adult teeth at 5-y follow-up ( ClinicalTrials.gov NCT00187837 and NCT00187850).

Managing Carious Lesions: Consensus Recommendations on Terminology.

Variation in the terminology used to describe clinical management of carious lesions has contributed to a lack of clarity in the scientific literature and beyond. In this article, the International Caries Consensus Collaboration presents 1) issues around terminology, a scoping review of current words used in the literature for caries removal techniques, and 2) agreed terms and definitions, explaining how these were decided.Dental cariesis the name of the disease, and thecarious lesionis the consequence and manifestation of the disease-the signs or symptoms of the disease. The termdental caries managementshould be limited to situations involving control of the disease through preventive and noninvasive means at a patient level, whereascarious lesion managementcontrols the disease symptoms at the tooth level. While it is not possible to directly relate the visual appearance of carious lesions' clinical manifestations to the histopathology, we have based the terminology around the clinical consequences of disease (soft, leathery, firm, and hard dentine). Approaches to carious tissue removal are defined: 1)selective removal of carious tissue-includingselective removal to soft dentineandselective removal to firm dentine; 2)stepwise removal-including stage 1,selective removal to soft dentine, and stage 2,selective removal to firm dentine6 to 12 mo later; and 3)nonselective removal to hard dentine-formerly known ascomplete caries removal(technique no longer recommended). Adoption of these terms, around managing dental caries and its sequelae, will facilitate improved understanding and communication among researchers and within dental educators and the wider clinical dentistry community.

Managing Carious Lesions: Consensus Recommendations on Carious Tissue Removal.

The International Caries Consensus Collaboration undertook a consensus process and here presents clinical recommendations for carious tissue removal and managing cavitated carious lesions, including restoration, based on texture of demineralized dentine. Dentists should manage the disease dental caries and control activity of existing cavitated lesions to preserve hard tissues and retain teeth long-term. Entering the restorative cycle should be avoided as far as possible. Controlling the disease in cavitated carious lesions should be attempted using methods which are aimed at biofilm removal or control first. Only when cavitated carious lesions either are noncleansable or can no longer be sealed are restorative interventions indicated. When a restoration is indicated, the priorities are as follows: preserving healthy and remineralizable tissue, achieving a restorative seal, maintaining pulpal health, and maximizing restoration success. Carious tissue is removed purely to create conditions for long-lasting restorations. Bacterially contaminated or demineralized tissues close to the pulp do not need to be removed. In deeper lesions in teeth with sensible (vital) pulps, preserving pulpal health should be prioritized, while in shallow or moderately deep lesions, restoration longevity becomes more important. For teeth with shallow or moderately deep cavitated lesions, carious tissue removal is performed according toselective removal to firm dentine.In deep cavitated lesions in primary or permanent teeth,selective removal to soft dentineshould be performed, although in permanent teeth,stepwise removalis an option. The evidence and, therefore, these recommendations support less invasive carious lesion management, delaying entry to, and slowing down, the restorative cycle by preserving tooth tissue and retaining teeth long-term.

Guided access cavity preparation using cone-beam computed tomography and optical surface scans - an ex vivo study.

AIM: To evaluate ex vivo, the accuracy of a preparation procedure planned for teeth with pulp canal obliteration (PCO) using a guide rail concept based on a cone-beam computed tomography (CBCT) scan merged with an optical surface scan. METHODOLOGY: A total of 48 teeth were mounted in acrylic blocks. An apical canal preparation was created to simulate remnants of an apical root canal that acted as the target for a drill path. The test blocks were surface scanned, and merged with a CBCT scan, and a guide rail was made. A pathway for the bur was created through a metal sleeve within the guide rail into dentine. The distance was measured between the centres of the performed drill path and the apical target by two examiners. A maximum distance of 0.7 mm was defined based on the radius of the bur (0.6 mm) and the radius of a root canal just visible on a radiograph (0.1 mm). The t-test was used for evaluation, and intra- and inter-examiner reproducibility was expressed by intraclass correlation coefficients. RESULTS: The mean distance between the drill path and the target was significantly lower than 0.7 mm, and null hypothesis H0 : µ = 0.7 was rejected (CI 95%: 0.31;0.49, P < 0.001). Intra- and inter-examiner agreements reached excellent levels. CONCLUSIONS: The combined use of CBCT and optical scans for the precise construction of a guide rail led to a drill path with a precision below a risk threshold. The present technique may be a valuable tool for the negotiation of partial or complete pulp canal obliteration.

[Medicolegal aspects of iatrogenic root perforations].

AIM: To retrospectively analyze the medico-legal aspects of iatrogenic root perforations (IRP) that occurred during endodontic treatments. METHODOLOGY: A comprehensive search in a professional liability insurance database was conducted to retrospectively identify cases of IRP following root canal treatments (RCTs). The complaints were categorized as either financial risk bearing or financial nonrisk bearing, and related demographic and endodontic variables were analyzed. RESULTS: One hundred and twenty cases of patients with IRP were identified. Twenty six cases (22%) were elective RCTs, and 94 cases (78%) were endodontic treatments performed due to pathologic processes (p < 0.05). Sixty cases (50%) were identified in mandibular molars, significantly more than other tooth locations (P < 0.05). In 102 cases (85%) the outcome was extraction, and in 18 cases (15%) the outcome was an additional treatment (p < 0.05). For both the cases with outcome of extraction and for the cases with an additional treatment, the complaints were judged as financial risk bearing in 95% of the cases. CONCLUSIONS: latrogenic root perforation is a complication of root canal treatment and may result in tooth extraction and in legal actions against the treating practitioner. Mandibular molars are more prone to medico-legal claims related to root perforations. The patient should be informed of the risks during RCT and should get information on alternative treatments and their risks and prognosis

Medico-legal aspects of vertical root fractures in root filled teeth.

AIM: To analyse the medico-legal aspects of vertical root fracture (VRF) following root canal treatment (RCT). METHODOLOGY: A comprehensive search in a professional liability insurance database was conducted to retrospectively identify cases of VRF following RCT. The complaints were categorized as either financial risk bearing or financial nonrisk bearing, and related demographic, prosthetic and endodontic variables were analysed. RESULTS: Seventy-seven legal cases of patients with VRFs following RCT were identified. Most of the cases were either in premolars or in mandibular molar teeth (P<0.05). Poor-quality root filling was associated with an extended delay of diagnosis (P<0.05). The presence of a post significantly increased the financial risk assessment (P<0.05). CONCLUSIONS: Poor quality root fillings complicate the diagnosis of VRF, which in turn extends the time for achieving an accurate diagnosis and increasing the medico-legal risk. Premolar and mandibular molar teeth were more prone to medico-legal claims related to VRF following RCT. Post should be placed only when essential for additional core support to avoid medico-legal risk.

Micro-CT analyses of apical enlargement and molar root canal complexity.

AIM: To compare the effectiveness of two rotary hybrid instrumentation techniques with focus on apical enlargement in molar teeth and to quantify and visualize spatial details of instrumentation efficacy in root canals of different complexity. METHODOLOGY: Maxillary and mandibular molar teeth were scanned using X-ray microcomputed tomography. Root canals were prepared using either a GT/Profile protocol or a RaCe/NiTi protocol. Variables used for evaluation were the following: distance between root canal surfaces before and after preparation (distance after preparation, DAP), percentage of root canal area remaining unprepared and increase in canal volume after preparation. Root canals were classified according to size and complexity, and consequences of unprepared portions of narrow root canals and intraradicular connections/isthmuses were included in the analyses. One- and two-way anova were used in the statistical analyses. RESULTS: No difference was found between the two techniques: DAP(apical-third) (P = 0.590), area unprepared(apical-third) (P = 0.126) and volume increase(apical-third) (P = 0.821). Unprepared root canal area became larger in relation to root canal size and complexity, irrespective of the technique used. Percentage of root canal area remaining unprepared was significantly lower in small root canals and complex systems compared to large root canals. The isthmus area per se contributed with a mean of 17.6%, and with a mean of 25.7%, when a narrow root canal remained unprepared. CONCLUSIONS: The addition of isthmuses did not significantly alter the ratio of instrumented to unprepared areas at total root canal level. Distal and palatal root canals had the highest level of unprepared area irrespective of the two instrumentation techniques examined.

Endodontic malpractice claims in Denmark 1995-2004.

AIM: To study the reasons for and outcome of malpractice claims handled by the regional and national Danish Dental Complaint Boards (DCB) from 1995 to 2004. Specific attention was paid to endodontic claims. Three hypotheses were explored: endodontic malpractice claims are frequent, they are mostly due to technical shortcomings and male dentists are overrepresented. METHODOLOGY: The reasons for the claims were classified and assigned to at least one of 14 categories. Cases assigned to the 'endodontic treatment' category were further sub-categorized, and reasons for malpractice were examined. An age and gender analysis of dentists and complaining patients was performed only on data obtained from the endodontic cases. RESULTS: Overall, 3611 malpractice claims were registered. In 43% of the cases the dentist was judged to be guilty of malpractice. In the majority of the appealed cases the original verdict was affirmed (62.2%) by the national DCB. After crown & bridge treatment (23%) endodontic treatment was the next frequent malpractice claim (13.7%), in which 'technical complications or incorrect treatment' was the most frequent sub-categorization (28.4%). Reasons for endodontic malpractice verdicts were related to root filling quality, the use of a paraformaldehyde product and instrument fracture. Male dentists were most often involved in an endodontic claim, and the majority of complainants were females. CONCLUSIONS: Endodontic malpractice claims were relatively common in Denmark. Perceived technical shortcomings dominated the patients' complaints concerning root canal treatment. Male dentists and female patients were overrepresented indicating a gender influence on aspects of the doctor-patient communication important for liability claims.