PRIDASE 2024 guidelines for reporting diagnostic accuracy studies in endodontics: A consensus-based development.

Studies investigating the accuracy of diagnostic tests should provide data on how effectively they identify or exclude disease in order to inform clinicians responsible for managing patients. This consensus-based project was undertaken to develop reporting guidelines for authors submitting manuscripts, which describe studies that have evaluated the accuracy of diagnostic tests in endodontics. These guidelines are known as the Preferred Reporting Items for Diagnostic Accuracy Studies in Endodontics (PRIDASE) 2024 guidelines. A nine-member steering committee created an initial checklist by integrating and modifying items from the Standards for Reporting of Diagnostic Accuracy (STARD) 2015 checklist and the Clinical and Laboratory Images in Publications (CLIP) principles, as well as adding a number of new items specific to the specialty of endodontics. Thereafter, the steering committee formed the PRIDASE Delphi Group (PDG) and the PRIDASE Online Meeting Group (POMG) in order to collect expert feedback on the preliminary draft checklist. Members of the Delphi group engaged in an online Delphi process to reach consensus on the clarity and suitability of the items in the checklist. The online meeting group then held an in-depth discussion on the online Delphi-generated items via the Zoom platform on 20 October 2023. According to the feedback obtained, the steering committee revised the PRIDASE checklist, which was then piloted by several authors when preparing manuscripts describing diagnostic accuracy studies in endodontics. Feedback from this process resulted in the final version of the PRIDASE 2024 checklist, which has 11 sections and 66 items. Authors are encouraged to use the PRIDASE 2024 guidelines when developing manuscripts on diagnostic accuracy in endodontics in order to improve the quality of reporting in this area. Editors of relevant journals will be invited to include these guidelines in their instructions to authors.

PROBE 2023 guidelines for reporting observational studies in endodontics: Explanation and elaboration.

Observational studies play a critical role in evaluating the prevalence and incidence of conditions or diseases in populations as well as in defining the benefits and potential hazards of health-related interventions. There are currently no reporting guidelines for observational studies in the field of Endodontics. The Preferred Reporting Items for study Designs in Endodontology (PRIDE) team has developed and published new reporting guidelines for observational-based studies called the 'Preferred Reporting items for OBservational studies in Endodontics (PROBE) 2023' guidelines. The PROBE 2023 guidelines were developed exclusively for the speciality of Endodontics by integrating and adapting the 'STrengthening the Reporting of OBservational studies in Epidemiology (STROBE)' checklist and the 'Clinical and Laboratory Images in Publications (CLIP)' principles. The recommendations of the Guidance for Developers of Health Research Reporting Guidelines were adhered to throughout the process of developing the guidelines. The purpose of this document is to serve as a guide for authors by providing an explanation for each of the items in the PROBE 2023 checklist along with relevant examples from the literature. The document also offers advice to authors on how they can address each item in their manuscript before submission to a journal. The PROBE 2023 checklist is freely accessible and downloadable from the PRIDE website (http://pride-endodonticguidelines.org/probe/).

PROBE 2023 guidelines for reporting observational studies in Endodontics: A consensus-based development study.

Observational studies are non-interventional studies that establish the prevalence and incidence of conditions or diseases in populations or analyse the relationship between health status and other variables. They also facilitate the development of specific research questions for future randomized trials or to answer important scientific questions when trials are not possible to carry out. This article outlines the previously documented consensus-based approach by which the Preferred Reporting items for Observational studies in Endodontics (PROBE) 2023 guidelines were developed. A steering committee of nine members was formed, including the project leaders (PD, VN). The steering committee developed an initial checklist by combining and adapting items from the STrengthening the Reporting of Observational studies in Epidemiology (STROBE) checklist and the Clinical and Laboratory Images in Publications (CLIP) principles, as well as adding several new items specifically for the specialty of Endodontics. The steering committee then established a PROBE Delphi Group (PDG) and a PROBE Online Meeting Group (POMG) to obtain expert input and feedback on the preliminary draft checklist. The PDG members participated in an online Delphi process to reach consensus on the clarity and suitability of the items present in the PROBE checklist. The POMG then held detailed discussions on the PROBE checklist generated through the online Delphi process. This online meeting was held via the Zoom platform on 7th October 2022. Following this meeting, the steering committee revised the PROBE checklist, which was piloted by several authors when preparing a manuscript describing an observational study for publication. The PROBE 2023 checklist consists of 11 sections and 58 items. Authors are now encouraged to adopt the PROBE 2023 guidelines, which will improve the overall reporting quality of observational studies in Endodontics. The PROBE 2023 checklist is freely available and can be downloaded from the PRIDE website (https://pride-endodonticguidelines.org/probe/).

Prevalence of painful temporomandibular disorders in endodontic patients with tooth pain.

BACKGROUND: Pain from temporomandibular disorders (TMDs) may mimic endodontic pain, but its prevalence in endodontic patients is unknown. OBJECTIVES: This cross-sectional study investigated the prevalence of painful TMDs in patients presenting for endodontic treatment of a painful tooth. Contribution of TMD pain to the chief complaint and characteristics associated with TMD prevalence were also assessed. METHODS: Patients reporting tooth pain in the 30 days before attending university clinics for nonsurgical root canal treatment or retreatment were enrolled. Before endodontic treatment, they completed questionnaires and a board-certified orofacial pain specialist/endodontic resident diagnosed TMD using published Diagnostic Criteria for TMD. Log-binomial regression models estimated prevalence ratios to quantify associations with patient characteristics. RESULTS: Among 100 patients enrolled, prevalence of painful TMDs was 54%. In 26% of patients, TMD pain was unrelated to endodontic pain; in 20%, TMD contributed to their chief pain complaint; and in 8%, TMD was a sole aetiology for pain. TMD prevalence was associated with greater intensity, frequency and duration of the chief pain complaint; pain in more than one tooth; tenderness to tooth percussion and palpation; a diagnosis of symptomatic apical periodontitis; pain medication use; and psychological distress. CONCLUSION: A majority of patients with tooth pain seeking endodontic treatment had painful TMDs; one quarter had TMD as a component or sole cause of their pain. TMD prevalence was associated with more severe symptoms and signs of tooth pain and with psychological factors. The high frequency of TMD comorbidity warrants consideration in management of endodontic patients with history of toothache.

The impact of cardiovascular disease and endodontic outcome: a systematic review of longitudinal studies.

OBJECTIVES: To date, the relationship between cardiovascular disease (CVD) and endodontic treatment outcomes remains elusive with mixed reports. Thus, the purpose of this systematic review of longitudinal cohort studies was to evaluate whether CVD was a risk factor for endodontic outcome. MATERIALS AND METHODS: Two reviewers independently conducted a comprehensive electronic database search to July 2020. The bibliographies of all relevant articles, textbooks, and gray literature were manually searched. The methodological quality of evidence was appraised by the Newcastle-Ottawa Scale and GRADE. The authors considered any publication on CVD and endodontic outcome. Endodontic outcome referred to either healing or survival of endodontically treated tooth. Risk ratio (RR) with 95% confidence interval (CI) was used. RESULTS: Three articles met the inclusion criteria with a low risk of bias. Patients with CVD demonstrated a 67% higher risk for negative endodontic outcomes compared with patients who were healthy (RR = 1.67, P = 0.001, 95% confidence interval 1.53-1.81). CONCLUSION: With the limitations of this systematic review, the overall confidence by GRADE was moderate suggesting that CVD might be a risk factor for endodontic outcomes. CLINICAL RELEVANCE: The results support an association between CVD and endodontic outcomes.

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: General introduction.

Traumatic dental injuries (TDIs) occur most frequently in children and young adults. Older adults also suffer TDIs but at significantly lower rates than individuals in the younger cohorts. Luxation injuries are the most common TDIs in the primary dentition, whereas crown fractures are more commonly reported for the permanent teeth. Proper diagnosis, treatment planning and follow up are very important to assure a favorable outcome. These updates of the International Association of Dental Traumatology's (IADT) Guidelines include a comprehensive review of the current dental literature using EMBASE, MEDLINE, PUBMED, Scopus, and Cochrane Databases for Systematic Reviews searches from 1996 to 2019 and a search of the journal Dental Traumatology from 2000 to 2019. The goal of these guidelines is to provide information for the immediate or urgent care of TDIs. It is understood that some follow-up treatment may require secondary and tertiary interventions involving dental and medical specialists with experience in dental trauma. As with previous guidelines, the current working group included experienced investigators and clinicians from various dental specialties and general practice. The current revision represents the best evidence based on the available literature and expert opinions. In cases where the published data were not conclusive, recommendations were based on the consensus opinions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. It is understood that guidelines are to be applied using careful evaluation of the specific clinical circumstances, the clinician's judgment, and the patient's characteristics, including the probability of compliance, finances and a clear understanding of the immediate and long-term outcomes of the various treatment options vs non-treatment. The IADT does not, and cannot, guarantee favorable outcomes from adherence to the Guidelines. However, the IADT believes that their application can maximize the probability of favorable outcomes.

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth.

Avulsion of permanent teeth is one of the most serious dental injuries. Prompt and correct emergency management is essential for attaining the best outcome after this injury. The International Association of Dental Traumatology (IADT) has developed these Guidelines as a consensus statement after a comprehensive review of the dental literature and working group discussions. It represents the current best evidence and practice based on that literature search and expert opinions. Experienced researchers and clinicians from various specialties and the general dentistry community were included in the working group. In cases where the published data did not appear conclusive, recommendations were based on consensus opinions or majority decisions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. The purpose of these Guidelines is to provide clinicians with the most widely accepted and scientifically plausible approaches for the immediate or urgent care of avulsed permanent teeth. The IADT does not, and cannot, guarantee favorable outcomes from adherence to the Guidelines. However, the IADT believes that their application can maximize the probability of favorable outcomes.

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 3. Injuries in the primary dentition.

Traumatic injuries to the primary dentition present special problems that often require far different management when compared to that used for the permanent dentition. The International Association of Dental Traumatology (IADT) has developed these Guidelines as a consensus statement after a comprehensive review of the dental literature and working group discussions. Experienced researchers and clinicians from various specialties and the general dentistry community were included in the working group. In cases where the published data did not appear conclusive, recommendations were based on the consensus opinions or majority decisions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. The primary goal of these Guidelines is to provide clinicians with an approach for the immediate or urgent care of primary teeth injuries based on the best evidence provided by the literature and expert opinions. The IADT cannot, and does not, guarantee favorable outcomes from strict adherence to the Guidelines; however, the IADT believes their application can maximize the probability of favorable outcomes.

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 1. Fractures and luxations.

Traumatic dental injuries (TDIs) of permanent teeth occur frequently in children and young adults. Crown fractures and luxations of these teeth are the most commonly occurring of all dental injuries. Proper diagnosis, treatment planning, and follow up are important for achieving a favorable outcome. Guidelines should assist dentists and patients in decision making and in providing the best care possible, both effectively and efficiently. The International Association of Dental Traumatology (IADT) has developed these Guidelines as a consensus statement after a comprehensive review of the dental literature and working group discussions. Experienced researchers and clinicians from various specialties and the general dentistry community were included in the working group. In cases where the published data did not appear conclusive, recommendations were based on the consensus opinions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. These Guidelines represent the best current evidence based on literature search and expert opinion. The primary goal of these Guidelines is to delineate an approach for the immediate or urgent care of TDIs. In this first article, the IADT Guidelines cover the management of fractures and luxations of permanent teeth. The IADT does not, and cannot, guarantee favorable outcomes from adherence to the Guidelines. However, the IADT believes that their application can maximize the probability of favorable outcomes.

Microbiological aspects of traumatic injuries.

After traumatic injuries to teeth, microorganisms may invade the compromised pulp tissue and initiate pulp infection and periapical inflammation. In addition to bone resorption that typically accompanies pulp necrosis, root resorption frequently occurs. Root resorption has several variants that may occur shortly after the trauma or at a later stage. The pathological changes seen after traumatic injuries to teeth are invariably linked to the presence of microbial irritants. The presence of bacterial biofilms in the dental pulp space can be treated with regenerative or therapeutic endodontic procedures. However, necrosis of periodontal ligament is usually terminal for the tooth involved. In this review, the sources of bacteria after traumatic injuries are discussed. The types and role of microorganisms involved in the pathogenesis of endodontic pathosis after traumatic injuries are presented, and contemporary approaches for the management of these conditions are reviewed. Contemporary antimicrobial strategies are discussed. The rationale for the use of systemic and topical antimicrobials is presented. Finally, novel approaches to the use of antimicrobial therapies, particularly in regenerative procedures, are reviewed.

Effect of bioactive dental adhesive on periodontal and endodontic pathogens.

The objectives of this study were to: (1) develop a new bioactive dental bonding agent with nanoparticles of amorphous calcium phosphate and dimethylaminohexadecyl methacrylate for tooth root caries restorations and endodontic applications, and (2) investigate biofilm inhibition by the bioactive bonding agent against eight species of periodontal and endodontic pathogens for the first time. Bonding agent was formulated with 5 % of dimethylaminohexadecyl methacrylate. Nanoparticles of amorphous calcium phosphate at 30 wt% was mixed into adhesive. Eight species of biofilms were grown on resins: Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Parvimonas micra, Enterococcus faecalis, Enterococcus faecium. Colony-forming units, live/dead assay, biomass, metabolic activity and polysaccharide of biofilms were determined. The results showed that adding dimethylaminohexadecyl methacrylate and nanoparticles of amorphous calcium phosphate into bonding agent did not decrease dentin bond strength (P > 0.1). Adding dimethylaminohexadecyl methacrylate reduced the colony-forming units of all eight species of biofilms by nearly three orders of magnitude. The killing efficacy of dimethylaminohexadecyl methacrylate resin was: P. gingivalis > A. actinomycetemcomitans > P. intermedia > P. nigrescens > F. nucleatum > P. micra > E. faecalis > E. faecium. Dimethylaminohexadecyl methacrylate resin had much less biomass, metabolic activity and polysaccharide of biofilms than those without dimethylaminohexadecyl methacrylate (P < 0.05). In conclusion, a novel dental adhesive was developed for root caries and endodontic applications, showing potent inhibition of biofilms of eight species of periodontal and endodontic pathogens, and reducing colony-forming units by three orders of magnitude. The bioactive adhesive is promising for tooth root restorations to provide subgingival margins with anti-periodontal pathogen capabilities, and for endodontic sealer applications to combat endodontic biofilms.

Association between diabetes and the prevalence of radiolucent periapical lesions in root-filled teeth: systematic review and meta-analysis.

INTRODUCTION: The question of whether diabetes mellitus can influence the outcome of root canal treatment (RCT) remains unclear. The aim of this systematic review and meta-analysis was to analyze scientific available evidence on the association between diabetes and the presence of radiolucent periapical lesions (RPLs) in root-filled teeth (RFT). METHODS: The review question was as follows: in adult patients who had endodontically treated teeth, does the absence or presence of diabetes result in an increase in the prevalence of RPL associated to RFT? A systematic MEDLINE/PubMed, Wiley Online Database, Web of Science, and Scopus search was conducted using the following MeSH and keywords: Diabetes Mellitus OR Diabetes OR Diabetic OR Hyperglycemia, AND Endodontics, Periapical Periodontitis, Periapical Diseases, Apical Periodontitis, Periradicular Lesion, Periapical Radiolucency, Radiolucent Periapical Lesion, Root Canal Treatment, Root Canal Preparation, Root Canal Therapy, Root Filled Teeth, Endodontically Treated Teeth. Seven studies reporting data on the prevalence of RPL associated to RFT both in diabetic and control subjects were included. RESULTS: After the study selection, seven epidemiological studies fulfilled the inclusion criteria, representing data from 1593 root canal treatments, 1011 in non-diabetic control subjects, and 582 in diabetic patients. The calculated pooled odds ratio (OR = 1.42; 95 % CL = 1.11-1.80; p = 0.0058) indicates that diabetic patients have higher prevalence of RFT with RPLs than controls. CONCLUSION: Available scientific evidence indicates that diabetes is significantly associated to higher prevalence of periapical radiolucencies in endodontically treated teeth, being an important putative pre-operative prognostic factor in RCT. CLINICAL RELEVANCE: Taking into account that diabetes is the third most prevalent chronic medical condition among dental patients, endodontic providers should be aware of the relationship between the outcome of endodontic treatment and diabetes.

Treponema spp. Shown to be Important Pathogens in Primary Endodontic Infections.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Prevalence of Treponema species detected in endodontic infections: systematic review and meta-regression analysis. Leite FRM, Nascimento GG, Demarco FF, Gomes BPFA, Pucci CR, Martinho FC. J Endod 2015;41(5):579-87. SOURCE OF FUNDING: No sources of funding are listed for this study TYPE OF STUDY/DESIGN: This study was a systematic review and meta-regression analysis.

Expression of Selected Inflammatory Mediators with Different Clinical Characteristics of Pulpal Inflammation.

INTRODUCTION: Accurately diagnosing the state of dental pulp is crucial when addressing tooth pain to determine the best treatment approach. This study aimed to investigate the concentration of inflammatory mediators in the dental pulp of mature teeth that have been exposed via caries but show no signs of apical periodontitis. METHODS: Samples of pulpal blood from adults with mature teeth responsive to pulp testing and have carious pulp exposures were obtained. These samples were analyzed for 12 inflammatory cytokines and other inflammatory proteins using the Luminex assay platform. Clinical factors were correlated with cytokine levels, and statistical analysis was performed to evaluate the impact of these factors on cytokine expression. RESULTS: Of the 36 patients that were included, 44.44% took pain medications, 33.33% had prolonged pulpal bleeding, 41.67% felt spontaneous pain, and 72.22% were diagnosed with symptomatic irreversible pulpitis. Significant correlations existed between presenting pain scores and levels of interleukin (IL)-1α, IL-6, and IL-8 (P < .05). Factors like analgesic medication intake, pain to percussion, pain to thermal testing, spontaneous pain, and nocturnal pain were significantly associated with higher levels of specific inflammatory proteins. No significant associations were observed with pain to palpation, bleeding time, or pulpal diagnosis. CONCLUSIONS: Inflammatory proteins, including cytokine levels may play a critical role in characterizing pulpal inflammation. Future studies should investigate the role of these potential biomarkers in determining the diagnosis of pulpitis and the prognosis of vital pulp therapy.

Incidence of Middle Mesial Canals in Mandibular Molars during Root Canal Treatment and Nonsurgical Retreatment.

INTRODUCTION: Large-scale clinical studies on the incidence of middle mesial canals (MMCs) in nonsurgical root canal treatment (RCT) and retreatment of mandibular molars are lacking. The primary aim of this observational study was to determine the incidence of MMCs in mandibular first and second molars that received RCT or nonsurgical retreatment (NSRetx). The secondary aim was to determine factors associated with incidence of MMCs. METHODS: Included were 3018 mandibular molars that received RCT (n = 1624) or NSRetx (n = 1394) by 3 endodontists in a private practice. Demographic and procedural data were collected. Bivariate and multivariable (Poisson regression model) analyses were performed. RESULTS: Incidence of MMCs was 8.8% (n = 267). Although the bivariate analysis showed that NSRetx was significantly associated with incidence of MMCs, this association did not reach the threshold for statistical significance after controlling for all covariates (P = .07). Multivariable analysis on the entire cohort showed that incidence of MMCs was significantly associated with younger age (risk ratio [RR] = 1.62; 95% confidence interval [CI], 1.28-2.06), male gender (RR = 1.48; 95% CI, 1.18-1.85), preoperative cone-beam computed tomography (CBCT) (RR = 1.48; 95% CI, 1.17-1.89), and first molar (RR = 2.30; 95% CI:1.74-3.05). Subgroup multivariable analyses revealed that incidence of MMCs was associated with male gender only in the RCT group (RR = 2.26; 95% CI, 1.55-3.30) but not in the NSRetx group (RR = 1.11; 95% CI, 0.82, 1.50); and with preoperative CBCT only in the NSRetx group (RR = 1.78; 95% CI, 1.28, 2.50) but not in the RCT group (RR = 1.10; 95% CI, 0.71, 1.69). Associations with younger age and first molar remained unchanged. CONCLUSIONS: Overall incidence of MMCs was 8.8%. Incidence of MMCs was significantly higher in younger patients and in mandibular first molars but was not associated with the type of treatment.

Diagnostic Accuracy of a Temporomandibular Disorder Pain Screener in Patients Seeking Endodontic Treatment for Tooth Pain.

INTRODUCTION: This study assessed the accuracy of a TMD Pain Screener questionnaire in identifying patients with temporomandibular disorder (TMD) pain among those seeking endodontic treatment for tooth pain. It also investigated whether the screener accuracy could be improved by adding questions regarding putative predictors of TMD status. METHODS: One hundred patients seeking endodontic treatment for tooth pain were enrolled. Participants completed the 6-question TMD Pain Screener before treatment. A board-certified orofacial pain specialist/endodontic resident conducted endodontic and TMD examinations using validated Diagnostic Criteria for TMD (DC/TMD). The sensitivity (Se), specificity (Sp), and positive/negative predictive values (PPVs/NPVs) were calculated for the 6-question and 3-question versions of the TMD Pain Screener. Logistic regression and receiver operating characteristic curve (AUROC) analyses were performed to determine the screening accuracy. RESULTS: At the screening threshold of ≥3, TMD Pain Screener's sensitivity was 0.85, specificity 0.52, PPV 0.68, and NPV 0.75 for the 6-question version and 0.64, 0.65, 0.69, and 0.61, respectively, for the 3-question version. The AUROC was 0.71 (95% CL: 0.61, 0.82) and 0.60 (95% CL: 0.48, 0.71) for full and short versions, respectively. Adding a rating of current pain intensity of the chief complaint to the screener improved the AUROC to 0.81 (95% CL: 0.72, 0.89) and 0.77 (95% CL: 0.67, 0.86) for full and short versions, respectively, signifying useful overall accuracy. CONCLUSIONS: The 6-question TMD Pain Screener, combined with the patient's rating of current pain intensity of the chief complaint, could be recommended for use in endodontic patients with tooth pain for detecting painful TMD.

Prevalence of Fusobacterium Species in Endodontic Infections Detected With Molecular Methods: Systematic Review and Meta-Analysis.

INTRODUCTION: Endodontic infections are polymicrobial; however, investigating the role of bacterial species is critical because they may influence pathogenesis, the development of symptoms, or the persistence of disease. This systematic review aimed to determine the prevalence of Fusobacterium species and its association with different types of endodontic infections. METHODS: MEDLINE (Ovid), PubMed, Scopus, Web of Science, and Cochrane Library databases were used as electronic databases to retrieve relevant studies. The studies were evaluated for eligibility criteria, and the certainty in evidence and risk of bias were evaluated using critical appraisal tools for prevalence studies from the Joanna Briggs Institute. Forty studies were selected for meta-analysis and statistically analyzed for the relationship between the prevalence of Fusobacterium species and both the presence of symptoms and the type of infections (primary vs secondary/persistent) using meta-regression analysis. RESULTS: The prevalence of Fusobacterium spp. in endodontic infections ranged from 3%-100% (mean = 42.51%) in the 40 included studies. Calculated confidence intervals indicated that the presence of Fusobacterium spp. was not statistically associated with the presence of symptoms or with the type of infections (the set of 2 predictors was not significant; P < .05). CONCLUSIONS: The prevalence of Fusobacterium infection, which was identified with molecular methods, was not significant for overall regression using both predictors (ie, symptoms [symptomatic vs asymptomatic] and types of infections [primary vs secondary/persistent]).

Flare-ups After Nonsurgical Retreatments: Incidence, Associated Factors, and Prediction.

INTRODUCTION: The aims of this study were to determine the incidence, associated factors, and predictability of flare-ups after nonsurgical retreatments (NSRetx). METHODS: All patients (n = 3,666) who received NSRetx by 3 endodontists in 2 endodontic offices during a period of 6 years (2016-2022) were included. Demographic, diagnostic, and procedural data were collected. A flare-up was defined as moderate-severe pain with/without swelling that took place within 14 days of initiation of NSRetx and resulted in an unscheduled appointment. Bivariate analyses on the entire cohort and multivariable analyses on cases with complete dataset (n = 2,846) were performed to identify significant associations. A Random Forest algorithm was used to make a prediction model. RESULTS: Incidence of flare-ups was 3.95% (n = 145). Increased risk of flare-ups was associated with diabetes (adjusted odds ratio [AOR] = 2.01; 95% confidence interval [CI], 1.01-3.97), mandibular teeth (AOR = 1.67; 95% CI, 1.11-2.52), moderate-severe preoperative pain on percussion (AOR = 2.13; 95% CI, 1.31-3.50), and pain on palpation (AOR = 1.63; 95% CI, 1.01-2.64). Lower risk of flare-up was associated with high blood pressure (AOR = 0.44; 95% CI, 0.21-0.82) (P < .05). The prediction model was not able to predict flare-ups with sufficient confidence (precision = 0.13). CONCLUSIONS: Incidence of flare-ups following NSRetx was low (∼4%) and had a weak but significant association with the history of diabetes. Moderate-severe pain on percussion, pain on palpation (any intensity), and mandibular teeth had a significant association with flare-ups. The history of high blood pressure was associated with lower risk of flare-ups. Flare-ups were difficult to predict in this clinical setting.

An Ex-Vivo Model for Investigating Bacterial Extrusion from Infected Root Canals during Masticatory Function.

INTRODUCTION: The extrusion of bacteria from infected root canals may lead to increase in symptoms, expansion of periapical lesions, and contribution to systemic diseases. The aim of this study is to investigate a potential proof-of-concept model to study the extent to which bacteria can escape from infected root canals under dynamic loading (simulated chewing). METHODS: The study was completed in 2 experiments performed at 2 institutions. Biofilms of Streptococcus intermedius in the first experiment and S. intermedius and Actinomyces naeslundii were allowed to grow in root canals of single-rooted extracted teeth for 3 weeks. The roots of the teeth were suspended in a small chamber containing dental transport medium and were mounted on a lower sample holder of a chewing simulator. In the experimental group, simulated chewing cycles equivalent to 1 year of function were conducted, and then bacterial migration was quantified and compared with stationary teeth. RESULTS: All experimental samples of the loading group revealed bacterial penetration in both experiments. Several of the unloaded samples revealed no bacterial penetration. In the first experiment, a significantly higher number of bacteria were able to escape into the periapex of the loaded group compared with the unloaded group (P = .017). In the second experiment, there was no significant difference between the 2 bacterial species used in the amount of extruded bacteria; however, there was a highly significant effect for occlusal loading (P = .0001). CONCLUSIONS: The potential for occlusal forces to enhance bacterial extrusion from infected root canals should be further explored.