Medical Research: Emerging Concepts and Applications Vol. 2

Three-Dimensional Imaging in Vital Pulp Therapy: Diagnostic Yield, Clinical Decision-Making, and Risk of Overdiagnosis

2026-08-20T10:48:27+00:00

Background: Cone-beam computed tomography (CBCT) provides three-dimensional visualisation of periapical tissues, root morphology, resorptive defects, and selected structural abnormalities that may not be evident on conventional periapical radiography. Its greater diagnostic yield, however, does not by itself establish that CBCT-guided decisions improve outcomes after vital pulp therapy (VPT).

Aim: To critically evaluate the diagnostic yield of limited-field-of-view CBCT in clinical situations relevant to VPT, determine how additional three-dimensional findings influence diagnostic thinking and treatment planning, and examine the risk that sensitive imaging may promote overdetection or unnecessary treatment escalation.

Methods: A structured critical narrative review was conducted using PubMed/MEDLINE and Scopus, supplemented by backward and forward citation tracking in Google Scholar. Literature published to 30 June 2026 was considered. Direct VPT evidence was prioritised. Diagnostic-accuracy, decision-impact, outcome, technical, and guidance publications from broader endodontic populations were included when they addressed imaging questions relevant to VPT. Evidence was organised according to diagnostic accuracy, influence on diagnostic thinking, influence on treatment planning, patient-outcome efficacy, and societal considerations.

Results: CBCT is more sensitive than periapical radiography for detecting apical periodontitis and can improve characterisation of resorptive defects, complex root anatomy, and selected structural abnormalities. In a human histopathological study, sensitivity for apical periodontitis was 0.89 for CBCT and 0.27 for a single digital periapical radiograph, with high specificity for both modalities. In the principal VPT-relevant clinical trial, CBCT detected more periapical changes than periapical radiography after indirect pulp treatment; baseline CBCT-detected lesions were associated with a higher observed failure rate, although the subgroup finding was not designed to define an independent treatment threshold. Studies in broader endodontic cohorts show that CBCT can change diagnoses, confidence, and treatment plans, especially in complex and preselected cases. Such changes are not equivalent to improved outcomes and may sometimes shift decisions towards more invasive care. Direct prospective evidence that CBCT-guided treatment selection improves pulp survival, tooth retention, pain, quality of life, or cost-effectiveness after VPT remains insufficient.

Conclusion: Limited-field-of-view CBCT can be valuable when a specific unresolved diagnostic question is likely to change management. It should not be used for routine screening of VPT candidates. Prescription should be individualised, use the smallest appropriate field of view, and integrate symptoms, sensibility testing, periodontal assessment, restorability, conventional imaging, and intraoperative pulp findings. Additional abnormalities should prompt clinical reassessment rather than automatic escalation to root canal treatment or extraction.

Infectious Agents in Human Carcinogenesis: A Critical Appraisal of Mechanisms, Attributable Burden and Vaccine-Based Prevention

2026-08-20T10:53:19+00:00

Chronic infection remains one of the few causes of human cancer for which the causal chain is understood at molecular resolution and for which primary prevention has already been demonstrated at population scale. Roughly one in eight incident cancers worldwide is attributable to an infectious agent, and the affected burden falls disproportionately on low-income and middle-income settings. Existing reviews of this field have tended to be organised agent by agent, to treat the two vaccine-preventable exemplars as templates for the remaining agents, and to give limited attention to the methodological architecture on which attributable-burden estimates rest. This review examines the field as a single evidentiary problem rather than a catalogue of pathogens. It evaluates how attributable fractions are constructed and where they are most fragile, compares direct and indirect mechanistic routes and asks what each route implies for the feasibility of vaccine-based control, and appraises the strength of the evidence that vaccination alters cancer incidence rather than surrogate endpoints. Human papillomavirus and hepatitis B virus vaccination are supported by registry-linked and cohort evidence extending to invasive cancer, although the two programmes differ substantially in the maturity, granularity and generalisability of that evidence. For hepatitis C virus, Helicobacter pylori, Epstein–Barr virus, Kaposi sarcoma herpesvirus, human T-lymphotropic virus type 1, Merkel cell polyomavirus and the carcinogenic helminths, prevention rests on treatment, screening or sanitation, and the barriers to vaccination are biological and economic rather than merely technical. Persistent uncertainties include the durability of reduced-dose schedules, the transferability of eradication-trial results to low-incidence populations, the causal status of candidate agents identified through sequencing, and the reasons why coverage failures rather than efficacy failures now dominate the gap between what is achievable and what is achieved. Prevention research priorities should shift towards implementation, long-horizon endpoints and settings where the burden is greatest.

From Calm to Crisis: A Critical Narrative Review of Definition, Mechanism and Risk in Endodontic Flare-Ups

2026-08-20T10:56:59+00:00

Severe pain, swelling, or both arising after the initiation or continuation of root canal treatment and prompting an unscheduled attendance is conventionally described as an endodontic flare-up. The event is uncommon, abrupt and disproportionately damaging to patient confidence, yet the literature that describes it remains unstable at its foundations. This critical narrative review examines how the flare-up has been defined, counted, mechanistically explained, predicted and prevented, and asks why four decades of investigation have produced neither a stable incidence estimate nor a usable prediction model. Literature was identified through structured searching of biomedical bibliographic and metadata sources, supplemented by citation tracking from recent syntheses, with every retained record verified against its indexing entry. Four themes are developed. First, the operational definition of flare-up varies in symptom threshold, observation window and ascertainment route across the primary studies that supply pooled estimates, so that reported incidences spanning roughly 0.4 per cent to 8 per cent are partly artefacts of measurement rather than reflections of biological variation. Second, the microbial, mechanical, chemical and neuroimmune explanatory frameworks are complementary in principle but have rarely been tested against one another in the same clinical cohort, and mechanistic plausibility has repeatedly been mistaken for demonstrated causation. Third, the risk-factor literature contains genuine contradictions, most conspicuously regarding periapical status and preoperative analgesic use, several of which are better explained by confounding by indication than by biological disagreement. Fourth, interventions promoted for flare-up prevention have almost invariably been evaluated against continuous postoperative pain scores rather than against flare-up occurrence, leaving preventive recommendations resting on a surrogate that shares neither the distribution nor the determinants of the event of interest. Priorities include a consensus case definition with a specified observation window, adequately powered prospective cohorts reporting absolute risks, and mechanistic studies that sample the periapical compartment. Until definitional agreement is reached, quantitative claims about flare-up frequency and causation should be treated as provisional.

Carbon Nanotubes in Conservative Dentistry and Endodontics: A Critical Appraisal of Mechanical, Antimicrobial and Regenerative Claims

2026-08-20T11:01:32+00:00

Carbon nanotubes (CNTs) have been advanced as reinforcing, antibacterial and bioactive additives for the materials used in conservative dentistry and endodontics, and the laboratory literature on this theme has expanded steadily over the past two decades. Enthusiasm derives largely from the intrinsic stiffness, aspect ratio and tunable surface chemistry of the isolated nanotube. The properties of an isolated tube and the properties of that tube once dispersed within a methacrylate, glass-ionomer, epoxy-resin or calcium silicate matrix are separated by processing steps that dental studies seldom characterise, and this gap shapes much of the disagreement in the field. This critical narrative review evaluates the evidence for CNT modification of restorative resins, dentine adhesives, acid-base cements, root canal sealers, vital pulp therapy materials and pulp-dentine tissue engineering scaffolds, together with the diagnostic and safety literature that constrains translation. Sources were identified through structured searching of biomedical and multidisciplinary bibliographic indexes and citation tracking, and were appraised for design adequacy, measurement validity, dose-response coherence and attribution of effect. Three findings dominate. First, mechanical benefit is real but narrow, confined to loadings near or below 1 per cent by weight, non-monotonic with concentration, and frequently matched or exceeded by conventional ceramic fillers tested in parallel. Second, most reported antimicrobial effects are confounded by silver, chlorhexidine or other payloads carried on the nanotube, so the independent contribution of the CNT itself remains poorly resolved. Third, regenerative claims rest predominantly on osteogenic and angiogenic surrogates in cells of dental origin rather than on odontoblastic differentiation or tubular dentine formation, and no clinical study in conservative dentistry or endodontics was identified. Safety evaluation is dominated by inhalation and fibre-pathogenicity models that map poorly onto a set, encapsulated dental material, while release, wear and degradation data are largely absent. Priorities include standardised reporting of nanotube provenance and dispersion state, dose-response designs with ceramic comparators, attribution-controlled antimicrobial testing, odontogenic endpoints and exposure assessment across the material life cycle.

Frailty in Gastrointestinal Surgical Oncology: A Critical Appraisal of Concepts, Measurement, Clinical Implications and Research Priorities

2026-08-20T11:06:40+00:00

Gastrointestinal malignancies are concentrated in later life, and resection remains the principal curative modality for most of them. Chronological age has proved an unreliable guide to who tolerates such surgery well, and frailty has consequently been adopted across gastrointestinal surgical oncology as a marker of diminished physiological reserve. Adoption has outpaced conceptual and methodological consolidation. This critical narrative review examines how frailty is defined, measured and interpreted in patients undergoing resection for colorectal, gastro-oesophageal and hepatopancreatobiliary cancer, and evaluates the strength of the evidence linking it to short-term morbidity, survival, functional recovery and patient-valued outcomes. Literature was identified through Europe PMC and Crossref Metadata Search together with citation tracking and targeted searching of publisher and registry records, with a final search date of 5 June 2026. Two observations dominate the synthesis. First, the term frailty designates several non-equivalent constructs in this literature, ranging from a physical phenotype to comorbidity-weighted administrative indices, and prevalence, effect size and even the direction of some comparative conclusions depend on which construct is operationalised. Second, the association between frailty and adverse postoperative outcomes is reproducible across tumour sites and data sources, but the evidence supporting a causal and modifiable role remains substantially weaker, and is complicated by the difficulty of separating ageing-driven vulnerability from tumour-driven catabolism in patients whose disease itself impairs nutrition. Randomised evidence for multimodal prehabilitation in colorectal cancer is encouraging but limited in generalisability to the frailest patients, and comparable evidence for gastro-oesophageal and pancreatic resection is scarce. Reports that mild to moderate frailty may not compromise long-term quality of life after colonic resection sit uneasily alongside the prevailing risk-centred narrative and deserve fuller examination. Priorities include construct-explicit reporting, prospective head-to-head instrument comparison in surgical cohorts, trials powered in genuinely frail patients, adoption of function-anchored endpoints, and evidence generation outside the small number of high-income health systems that presently dominate the field.

Teaching Clinical Reasoning in Nephrology: Theory, Practice, and Educational Evaluation

2026-08-20T11:09:55+00:00

Introduction: Clinical Reasoning Learning (CRL) sessions enable students to engage in contextualised, student-centred learning activities.

Aim: This study aimed to assess the immediate educational impact of three CRL sessions on nephrology trainees.

Study Design: A pre- and post-evaluation study was conducted.

Study Location and Date: The Nephrology Department at Mongi Slim Hospital.

Methodology: The study involved 24 students divided into three groups during three different internship periods across the 2023/2024 and 2024/2025 academic years. Each group participated in three CRL sessions, each lasting 60 minutes. These sessions focused on the theme of “raised creatinine.” The immediate pedagogical effectiveness was evaluated based on cognitive gains, measured using a knowledge questionnaire administered before (pre-test) and after (post-test) each CRL session, and student satisfaction, assessed using an opinion questionnaire. Results: The CRL sessions were conducted interactively in accordance with the pre-established scenario.

Results: The median student score was 10.25/20 points [2.75-15] at the pre-test, compared with 11.75/20 points [6-16.75] at the post-test. The average pre-test score across the three CRL sessions was 9.48/20, while the average post-test score was 11.95/20. Overall, 18 students improved their scores, and the mean score increased by 2.47 points. All students either agreed or strongly agreed that the session timing was appropriate, that the sessions were interactive, that they better understood the course material, that they better understood the diagnostic process, and that these sessions were an effective learning method.

Conclusion: The findings suggest that CRL sessions may be a valuable educational tool for learning clinical reasoning during tutorial sessions organised within clinical internships. However, successful implementation also requires concurrent investment in the pedagogical training of teaching staff.

A Critical Narrative Review of Tooth Fragment Reattachment After Traumatic Crown and Crown-Root Fractures

2026-08-20T11:12:36+00:00

Traumatic crown fractures of permanent anterior teeth are common in children and young adults, and the availability of an intact tooth fragment creates a distinctive restorative opportunity: preservation of the patient's own enamel, dentine, morphology and surface texture rather than reconstruction with an artificial substitute. This critical narrative review integrates biological, adhesive, biomechanical and clinical evidence on tooth-fragment reattachment, with particular emphasis on where laboratory findings do and do not translate into durable clinical outcomes. Literature was selected through live searches of accessible scholarly sources, supplemented by citation chasing and verification of bibliographic metadata and Digital Object Identifiers. The evidence indicates that fragment reattachment is a highly conservative option when the fragment is retrievable, structurally usable and accurately repositionable, and when the fracture margins can be isolated. Hydration of a dehydrated fragment is consistently supported by laboratory evidence, although optimal storage media and rehydration duration remain uncertain. Preparation designs such as chamfers, overcontouring and internal grooves often increase immediate fracture resistance relative to simple reattachment, but added preparation sacrifices tissue and may shift failure towards less repairable tooth-substrate fracture. Clinical evidence is substantially weaker than the laboratory literature. Retrospective cohorts and a recent meta-analysis suggest that fragment loss is a meaningful long-term risk and that direct composite restoration may show greater restorative survival in some settings, while other cohorts report similar outcomes. Crown-root fractures can remain functional for years after adhesive reattachment, but periodontal compromise and repeated restorative or endodontic intervention are common. The most defensible strategy is therefore risk-calibrated rather than technique-driven: preserve pulp vitality where possible, maintain fragment hydration, secure isolation, minimise unnecessary preparation, assess occlusal loading and associated luxation injury, and plan surveillance and repairability from the outset. Better prospective comparative studies with standardised outcomes are needed before any single reinforcement protocol can be considered superior.