Sebastian Fitzek

Background/Objectives: To compare mechanical behavior, shaping performance, and safety of an original reciprocating endodontic instrument (Reciproc^® Blue) with two visually similar replicas obtained from an online marketplace. Methods: The original Reciproc^® Blue and two replica (designated Replica 1 and Replica 2) instruments purchased from AliExpress were tested. Evaluations included torque resistance, bending resistance, cyclic fatigue resistance (all according to ISO 3630-1 standards, n = 10 per group per test), and an in vitro shaping procedure using artificial root canals in plastic blocks (5 canals per instrument, n = 10 instruments per group) were carried out. Preparation time, number of pecks, procedural errors (blockages, ledges, deformations), and instrument fractures were recorded. Surface characteristics of unused (n = 2) and used instruments (n = 2) were examined using scanning electron microscopy (SEM). Statistical analysis used one-way ANOVA, Welch ANOVA, or Kruskal–Wallis tests according to the distribution and variance pattern of each endpoint, followed by the corresponding post hoc test. Repeated use was analyzed with a linear mixed effects model and checked with a robust generalized estimating equation sensitivity analysis. Deformation-free and fracture-free event curves were compared with exploratory log rank tests. Results: The original instrument showed the highest Mf/D³ and Mt/D³ values. Overall group differences were significant for Mf/D³ (Welch p < 0.001) and Mt/D³ (Welch p = 0.001), with significant Games Howell contrasts between the original and Replica 2. Replicas showed longer cyclic fatigue life (Original 407.1 s, Replica 1 490.2 s, Replica 2 607.8 s; ANOVA p < 0.001). The original instrument had a lower average preparation time for each canal than both replicas (72.8 s vs. 95.8 s and 92.3 s; Kruskal–Wallis p < 0.001) and a lower average number of pecks (8.64 vs. 9.71 and 10.00; p = 0.008). Exploratory log rank comparisons also showed group differences in the deformation-free and fracture-free event curves (Holm adjusted p = 0.005 and p = 0.024, respectively). Both replicas failed to reach working length in 4 out of 10 cases each, with high rates of blockages (Replica 1: 7/10; Replica 2: 2/10), ledges (Replica 1 only), and deformations. The limited SEM subsample revealed severe wear of cutting edges in Replica 1. Conclusions: Both tested replicas exhibited significant deviations in mechanical behavior and markedly inferior shaping safety compared to the original Reciproc^® Blue instrument, despite superficial visual similarity. Therefore, dental practitioners should be aware that low-cost imitations may compromise clinical safety.

Background/Objectives: Maxillary sinus floor augmentation (MSFA) via the lateral approach is a well-established procedure for prosthetic rehabilitation of atrophic posterior maxillae. However, late complications are often nonspecific, with an incompletely understood aetiology. We evaluated patients with atypical late complications post-MSFA with bovine xenohybrid bone substitute NaturesQue SemOss B (BEGO GmbH, Bremen, Germany), describing their presentation, management, and outcomes. Methods: This retrospective, complication-selected clinical case series examined 47 patients who underwent lateral window MSFA with this graft from September 2020 to March 2023 in a single university department. Twelve complication cases were identified during the study period. Atypical late complications were defined as graft-associated clinical and/or radiological adverse outcomes, excluding peri-implantitis, that first manifested > 6 mo postoperatively. Baseline characteristics, perioperative findings, conservative and surgical management (including graft removal and reaugmentation), histology, and follow-up were assessed. Results: Twelve complication cases were identified among 47 patients treated during the study period. Seven experienced implant loss; seven, partial or complete lack of graft osseointegration; six, pain; and seven, signs of sinus infection. Histological analysis (6/12) revealed lymphocytes, plasma cells, and fibroblastic changes without detectable macrophages. No intraoperative complications were observed. Conclusions: Atypical late complications affected 25.5% of the patients. Despite comprehensive clinical, radiological, and histological assessments, the aetiology remained unclear, and the findings did not indicate a peri-implantitis-type infection; we hypothesised impaired early phase wound healing These patients were amenable to repeat augmentation post-non-osseointegrated graft removal, although larger studies are required.

Background/Objectives: The aetiology of facial clefts remains incompletely understood, and ionising radiation has been discussed as a potential exogenous factor. This review investigated the epidemiology of cleft lip and/or palate (CL/P) in Germany in relation to the Chernobyl NPP accident. Methods: A systematic literature search was conducted using MEDLINE, LIVIVO, and the Cochrane Library, supplemented by additional searches. OHAT risk-of-bias domains were applied to the included studies. Results: In total, 276 potentially relevant records were identified, of which six were included. Studies from Bavaria and the former German Democratic Republic reported regional associations between increased CL/P prevalence and the Chernobyl NPP accident. None of the included studies assessed radiation exposure at the individual level; exposure assessment was regional or ecological. Conclusions: Associations were reported in some more heavily contaminated regions, whereas no statistically significant differences were found in regions affected by lower levels of fallout. One study reported an estimated additional regional exposure of 1.2 mGy in the most heavily contaminated areas. This estimate does not substitute for individual dosimetry and should be interpreted cautiously. Experimental and other sources cited in the review discuss malformation effects at doses of at least 50 mGy. Given the heterogeneous study designs, ecological exposure assessment, inadequate control of confounding, and very low certainty of evidence, the available data do not support establishing a causal relationship between Chernobyl-related exposure and CL/P in Germany.

As artificial intelligence (AI) evolves from passive decision-support tools to agentic clinical assistants – capable of drafting documentation, synthesizing complex cases, and automating surgical workflows – the educational requirements for clinicians are fundamentally changing. This transition represents a pivotal moment in medical history, akin to the introduction of medical imaging, yet the workforce remains largely unprepared for the shift from “human-in-the-loop” to “human-on-the-loop” interaction. This chapter addresses the critical gap between the rapid deployment of multimodal large language models (MLLMs) in medicine and the current lack of formal AI literacy in medical and surgical curricula. We propose a comprehensive framework for training the “agentic clinician”, built on three interdependent pillars: advanced technical literacy, human-centered design (HCD), and regulatory compliance under the new EU AI Act. Drawing on recent analyses and surveys of medical and dental students regarding trust, perceived roles, and preparedness, we outline a pragmatic curriculum that maps AI competencies onto existing clinical rotations. We then present a human-centered integration checklist for wards and operating rooms designed to mitigate risks such as, automation bias, hallucinations, and loss of situational awareness. Finally, the chapter operationalizes the EU AI Act by translating high-risk classification and postmarket monitoring obligations into concrete policies for hospitals and training programs. This roadmap is intended to empower educators and decision-makers to cultivate a workforce capable of safely supervising autonomous systems, ensuring that AI remains a tool for augmenting – rather than replacing – human clinical judgment.

Background: In everyday practice, we observed an increased number of complications with a xeno-hybrid bovine graft in challenging cases, prompting a systematic review of timing strategies and the impact of the operator. Objective: To compare early safety and rehabilitation timelines for immediate versus delayed implant placement after alveolar ridge procedures with a xeno-hybrid bovine graft, and to examine operator-level effects. Materials and Methods: Single center retrospective cohort (Danube Private University, Krems, Austria; January 2021–October 2023). Consecutive patients undergoing alveolar ridge preservation (ARP) or reconstruction (ARR; conservative protocol without meshes or rigid frameworks) with a xeno-hybrid bovine graft and subsequent implant were included. Strata: ARP, ARR, ARP with immediate implant placement (ARP+II), ARR with immediate implant placement (ARR+II). Primary endpoint: early implant loss < 12 months after the index surgery. Secondary endpoints: days to implant exposure and days to definitive prosthesis. Results: We analyzed 158 coded interventions (ARP 33; ARR 16; ARP+II 32; ARR+II 77). Early implant loss was uncommon (7/158; 4.4%) and occurred only with immediate implant placement (ARP+II 6.3%; ARR+II 6.5%); no early failures occurred in delayed strata. Immediate implant placement accelerated rehabilitation (exposure: 358/364 vs. 144/162 days; prosthesis: 406/419 vs. 196/204 days; both p < 0.0001). After adjustment for treatment base, timing, and age, no independent operator level effect on early loss was detected. Conclusions: In this university cohort using a xeno-hybrid bovine graft, early implant loss was rare and confined to immediate implant placement, which nonetheless shortened the pathway to exposure and restoration by ~5–7 months. Differences across providers were explained by case selection and protocol choice after adjustment. Clinical Significance: With appropriate case selection and surgical execution, immediate implant placement after ARP/ARR can reduce treatment time by ~5–7 months without a clear increase in early failure within the limits of this cohort; treatment protocol and case triage are the main levers of early outcome.

Background and Aims: Asexual adults often report misunderstandings during clinical encounters. We described romantic attachment (ECR‐R anxiety/avoidance) in an asexual sample and tested whether disclosure in medical settings was associated with feelings of misunderstanding, stigma, and a (dis) comfort‐discussing orientation. Methods: This was a cross‐sectional online pilot survey ( N = 47, aged 18–67 years). Variables: Disclosure (no/never, depends/sometimes, yes/always), Likert outcomes (1–5), ECR‐R (1–7), and age. Analyses: ordinary least squares (OLS) with HC3 robust SEs; ordered logit sensitivity analyses (odds ratios, 95% CI) in Supplement S1; multiplicity controlled via Benjamini–Hochberg FDR. Results: Mean ECR‐R scores: anxiety 3.28 (SD 1.30), avoidance 3.47 (SD 1.41). Avoidance was higher in sex‐averse than in sex‐favourable participants (Hedges' g = 1.285; 95% CI 0.449–2.769). Relative to never disclosing, “depends/sometimes” was associated with greater misunderstanding (OR 5.69; 95% CI 1.45–22.32) and stigma (OR 5.32; 1.30–21.80), whereas “yes/always” was associated with less discomfort (OR 0.05; 0.00–0.68). Estimates for “always” disclosure reflect a small subgroup ( n = 4). Key contrasts were robust to FDR adjustment, and ordinal models were directionally consistent. Conclusion: Disclosure patterns are related to reported healthcare experiences of asexual patients. Non‐presumptive sexual history taking, patient‐led disclosure options (e.g., an “asexual” field), and asexuality‐competent communication training may improve care. Larger multi‐site studies are warranted.

Background/Objectives: Cone beam computed tomography (CBCT) is vital in endodontics but suffers from beam-hardening artifacts caused by metallic restorations, which can obscure diagnostic details. This study evaluated a novel patient positioning protocol—a controlled head tilt—designed to mitigate these artifacts by moving contralateral metallic structures outside the primary X-ray path in small field of view (FoV) CBCTs. Methods: Using a skull phantom with metallic restorations CBCT scans were acquired in three positions: standard alignment, a 12° tilt toward the region of interest (ROI), and a 12° tilt to the opposite side. Fifty experienced dentists, blinded to the protocol, subjectively compared image quality and artifact severity between the tilted and reference images. Results: The tilt away from the ROI was rated as providing better image quality significantly more often than the tilt towards the side of the ROI (442 of 585 non-tied comparisons; p < 0.001). A complementary rater-clustered GEE analysis adjusted for slide confirmed higher odds of “better” ratings under head tilt away from the ROI for image quality (OR = 4.16, 95% CI 3.12–5.56) and artefacts (OR = 2.87, 95% CI 1.93–4.26). An individual head tilt significantly improves subjective small-FoV CBCT image quality, most evidently in the longitudinal plane, by reducing artifact interference from contralateral metals, and should be considered a practical strategy for clinical use, and may serve as a practical chairside strategy, pending clinical validation.