Aim: To prospectively investigate the incidence of symptoms and changes in the size of the apical bone destruction in symptom-free root-filled teeth with persistent apical periodontitis (AP) over 1 year without treatment.

Methodology: Patients referred to two specialist endodontic clinics in Västra Götaland, Sweden, with asymptomatic periapicalbone destructions (summing to ≤ 10 mm in diameter, when measured in two dimensions) on intraoral radiographs were invited.After informed consent, participants underwent cone-beam computed tomography (CBCT). Patients with bone destructionsbeyond cortical boundaries were excluded. A 1-year follow-up included recording subjective symptoms, clinical findings andestimating bone destruction size.

Results: Of 187 eligible patients, 171 (91.4%) participated. After CBCT, four were excluded, and 10 were lost to follow-up. Among 157 patients, three developed symptomatic AP and were treated, and one tooth was lost due to fracture. Of the 153 patients with complete follow-up, eight (5.2%) reported mild pain or discomfort but did not seek care. Lesion size changes were small(M = 0.059 mm), with the mean increasing from 7.25 mm (SD 2.11) to 7.31 mm (SD 2.33), which was not statistically significant.

Conclusion: The findings align with previous studies, suggesting that patients with symptom-free root-filled teeth with apicalperiodontitis rarely experience exacerbation or significant increase in size of bone destruction in the short term. Longer follow-upis needed to identify potential risk factors.

Background: An overwhelming majority of root‐filled teeth are asymptomatic, despite commonly exhibiting radiological signs of apical periodontitis (AP). When symptoms prevail, several sources are conceivable. This case–control study investigates underlying causes of pain from root‐filled teeth.

Objectives: The aims were to (i) compare painful root‐filled teeth with root‐filled teeth without pain matched on sex, age, jaw and tooth type, and (ii) explore patient‐ and tooth‐related factors that may explain the pain.

Methods: Adult participants (≥ 20 years) with root‐filled teeth were investigated through anamnestic, clinical and radiographic examinations. Analyses compared painful to pain‐free teeth statistically, and possible origins of pain were indicated. Clinical data and periapical radiographs were used to identify the presence of AP.

Results: Tenderness to percussion and apical palpation , probing depth ≥  6 mm , swelling and apical radiolucency ( p  = 0.002–0.040) were more common with painful teeth, while density and length of root filling , unfilled canals , fracture of root and positive screening for TMD (3Q/TMD) did not differ between groups ( p  = 0.074–0.63). Among the 55 symptomatic teeth, AP was identified in 48 with varying diagnostic certainty. Indication of temporomandibular disorder (TMD) was present in 15 teeth, and marginal periodontitis (MP) in eight teeth. For six teeth, none of the three conditions could be identified.

Conclusions: Tenderness to percussion and apical palpation , swelling , pocket depth ≥  6 mm , and apical radiolucency were more common with painful teeth. The pain was most frequently associated with AP, but pain due to TMD and MP may occur. For 10% of the root‐filled teeth, no findings could explain the symptoms.

Aim: In uncertain clinical situations, such as assessing the risk of exacerbation of apical periodontitis in root-filled teeth, un-dergraduate students can benefit from being trained to reflect. This study aimed to explore how students specifically reflectedon clinical experiences in relation to uncertainty when assessing a case involving a root-filled tooth with apical periodontitis.

Methodology: Short reflections were written by 52 dental students at Malmö University in 2021. All students were asked toreflect on the risk for exacerbation of apical periodontitis in a case with a root-filled tooth with a diffuse widening of the perio-dontal ligament space. The reflections were written according to prompts developed to stimulate reflection. For each student, thereflections were analysed by a qualitative method, Systematic Text Condensation (STC).

Results: The analysis of the qualitative data resulted in the formulation of two themes about experience and lack of experience:Theme 1 ‘The meaning of clinical experience’ and Theme 2 ‘Differences and similarities’. The themes were subdivided into ninesubgroups and described the relationship between experience and certainty.

Conclusions: The students believed that certainty comes with experience even when there is a lack of scientific evidence

Objectives: In National Dental Practice-Based Research Network practices (PBRN; NationalDentalPBRN.org), assess (i) diagnostic accuracy of cold testing for pulp vitality determination, and (ii) influence of symptoms and individual- and tooth-related characteristics on diagnostic accuracy.

Methods: In this prospective cohort study, 1,696 PBRN patients each contributed one tooth undergoing non-surgical root canal treatment. The index test was cold test of the pulp performed before treatment initiation. The reference standard was pulp bleeding upon access cavity preparation. Diagnostic validity measures included sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, and overall test accuracy. Data analyzed for their influence on validity included dentist training level, case characteristics (demographics, tooth type, clinical and radiographic findings, symptoms, pain medication intake) and psychosocial assessment (treatment fear, expectations of outcome, pain catastrophizing, depression, anxiety, perceived stress). Generalized estimating equations (GEE) were used to assess statistical significance of differences between subgroups.

Results: The prevalence of vital pulp was 48% (810/1,696). Overall sensitivity of the cold test to identify vital pulp was 83% (95% CI 81%–86%), specificity 74% (71%–77%), PPV 74% (72%–77%), NPV 83% (80%–85%) and overall accuracy 78% (76%–80%). Multivariate regression analyses are ongoing but preliminary results indicate significantly lower sensitivity but higher specificity for teeth displaying an apical radiolucency, for teeth non-tender to palpation, and in patients aged 55+; and significantly higher sensitivity but lower specificity for molar teeth compared to non-molars. Overall test accuracy did not differ significantly for any of these factors. All measures were higher when assessed by endodontists (p<.001).

Conclusions: When performed in PBRN practices, cold testing correctly identified vitality status of about 8 of 10 pulps. Case characteristics have potential to influence test validity and may need to be considered when interpreting a test result.

AIM: Threshold concepts are concepts that, when grasped, will promote mastery of a subject by leading to proper understanding of its most central features. Some features of threshold concepts are that they are transformative, troublesome, irreversible, integrative, and bounded. The aim of this study is to report on the development and initial assessment of threshold concepts introduced in undergraduate endodontic education at Malmö University.

Methodology: By systematically reviewing published literature we evaluated how threshold concepts affect students’ experiences in dental or medical education. Through collegial discussions three central concepts were identified: “Physical and physiological barriers”, “Gradual disease development” and “Localization of inflammation/infection”. These concepts were then integrated into all theoretical learning activities in Endodontology. At the written examination, the students replied in short essays to questions about pathogenesis regarding pulpal and periapical disease. Through systematic text condensation (Malterud 2012) the answers were analyzed to discover whether their arguments indirectly or directly reflected the threshold concepts.

Results: The systematic review failed to identify studies evaluating how threshold concepts affect students’ experiences in dental education. Four papers from medical education reported that threshold concepts act as tools to overcome obstacles and foster new ways of thinking. The systematic text condensation identified four main themes: “Barrier functions and their role in the pulp defense”, “Inflammation and infection in the pulp and surrounding tissues”, “Clinical approach to endodontic diagnostics” and “Details of disease development”. These main themes were then further divided into subthemes. The results showed that the students reflected well on the central concepts of Endodontology and showed good understanding of the meaning of threshold concepts.

Conclusions (mandatory): The identified concepts were integrated into the learning activities and seem to have affected the students’ ability to grasp central concepts within Endodontology. Further studies are needed to confirm whether learning the concepts also promoted retention of knowledge over time.

OBJECTIVE: In vitro leakage studies suggest that temporary restorations only provide a short-term seal. However, it remains unclear whether the clinical outcome is impacted by the time elapsing between the completion of a root canal treatment (RCT) and the placement of a direct permanent coronal restoration. The aim was to investigate any time-dependent difference in frequencies of endodontic orthograde retreatment, apical surgery and extractions during the subsequent 5 years following root filling of first molars restored with a direct restoration depending on immediate or delayed time between completion of RCT and placement of a direct restoration.

MATERIAL AND METHODS: Data from the Swedish Social Insurance Agency was collected. In 2009, 50,314 direct restorations were registered after RCT of the first molars in individuals aged 20 years or older. The teeth were divided into five time intervals depending on time from completion of root filling to placement of direct restoration for comparisons of frequencies of orthograde retreatment, apical surgery and extractions, during the following 5 years. The time interval categories were compared using Pearson's Chi-square test.

RESULTS: No statistically significant time-dependent differences in registrations were found for orthograde retreatment (p = 0.089), with or without apical surgery (p = 0.161) and with or without extraction (p = 0.737).

CONCLUSION: The time elapsed from the completion of RCT and the placement of a direct restoration did not affect the 5-year outcome of the RCT.

'Temporomandibular disorders' is an umbrella term for disorders of the temporomandibular joints, the masticatory muscles, and the adjacent anatomical structures. On behalf of the International Network for Orofacial Pain and Related Disorders Methodology, this article gives an overview of key points for good clinical practice in the field of temporomandibular disorders. During an annual conference in March 2024, members of the aforementioned network drew up a list of 10 core principles. These core principles include knowledge about the causes, diagnosis and treatment of temporomandibular disorders. They summarize the current standard of care for the treatment of such conditions and are in keeping with the need to help increase the expertise of dentists working in general practice and to prevent incorrect treatment. The core principles can be regarded as a starting point for other national and international organisations to use to develop guidelines and recommendations for the treatment of temporomandibular disorders.

Background/AimPersistent idiopathic facial pain (PIFP) is a rare condition with a lifetime prevalence of approximately 0.03%. It is characterized by persistent daily facial pain without identifiable cause and presents diagnostic and therapeutic challenges due to unknown pathophysiology, symptom overlap with other painful disorders, and limited evidence-based treatments. The aim of this Delphi study was to establish international consensus-derived guidelines for the management of patients with PIFP.MethodsA three-round Delphi study was conducted with 16 international pain experts, each with ≥10 years of clinical experience in pain management and extensive peer-reviewed publications. The first round involved open-ended questions, and the qualitative data were analyzed using systematic text condensation, resulting in a quantitative questionnaire with 42 statements. Subsequent rounds employed Likert-scale responses to these statements. Consensus was defined as ≥80% agreement or disagreement. In addition, if 11-12 (68-75 percent) out of the 16 experts agreed or disagreed, consensus was not reached, but a majority was considered to have a particular opinion.ResultsConsensus was reached in 35 out of the 42 statements (83%), emphasizing multidisciplinary collaboration and avoidance of invasive procedures in the treatment of PIFP. In an additional three statements (7%) a majority of the experts agreed with each other. In four statements (10%), no consensus or majority was reached. Pharmacological treatments, including tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors, and gabapentinoids, may be considered; however, opioids should generally be avoided in the treatment of PIFP. Patient education and behavioral therapies are important interventions, and the most important measure of therapeutic success is improved quality of lifeConclusionThe present Delphi study has established internationally derived consensus guidelines and recommendations for the evaluation and comprehensive management of patients with PIFP. This is a first step in gathering knowledge for future evidence-based guidelines and more specific treatment recommendations. These international expert consensus guidelines recommend a multi- or interdisciplinary approach in managing PIFP, avoiding invasive interventions and prioritizing patient-centered outcomes.

AIM: To assess (i) diagnostic accuracy of cold testing, and (ii) influence of symptoms and individual- and tooth-related characteristics on diagnostic accuracy, in teeth undergoing RCT in National Dental Practice-Based Research Network practices (PBRN; NationalDentalPBRN.org)

Methodology: In a prospective cohort study, 1,696 PBRN patients treated by 153 dentists (104 GDPs, 49 endodontists) each contributed one tooth undergoing non-surgical RCT. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, and overall test accuracy were evaluated for pre-operative cold pulp test (index test) with non-bleeding (non-vital) pulp upon access cavity preparation as the reference standard. Background factors including dentist training level and age, case characteristics (demographics, tooth type, clinical and radiographic findings, symptoms, pain medication intake) and psychosocial variables were analyzed for their influence on test validity. Generalized estimating equations (GEE) assessed differences between subgroups at p<0.05 significance level.

Results: The prevalence of non-vital pulp in the sample was 52% (886/1,696). The overall accuracy of the cold test to identify a non-vital pulp was 78% (76%–80%); sensitivity 74% (95% CI 71%–77%), specificity 84% (81%–86%), PPV 83% (80%–85%), and NPV 74% (72%–77%). GEE models indicated that psychosocial and pain-related variables (treatment fear, and severe worst pain the previous week, screening positive for TMD), individual- and tooth-related variables (patient age, palpation tenderness, molar teeth, teeth with crown) and dentist-related variables (training, age) affected the accuracy measures significantly in various directions (adjusted means; ranges -18% to 14% and ORs 0.30 to 3.05; p<0.001–0.04). Overall accuracy was higher for endodontists but lower for dentists aged 65+ and in patients with severe pain.

Conclusions (mandatory): Cold testing, when performed in PBRN practices, correctly identified the vitality status of about 8 of 10 pulps. A complex interaction between patient, tooth/disease, and dentist factors influences test validity and need to be considered when interpreting a test result.

Acknowledgements (optional): Supported by NIH grants U19-DE-22516 and U19-DE-28717