Ana Maria Cristina Țâncu

Nanohybrid resin composites are the dominant class of direct restorative materials, yet evidence on individual products is dispersed and difficult to compare. This narrative review appraises the composition, physicomechanical, chemical, optical, and clinical behaviour of Filtek™ Z550 (introduced in 2012), an extensively tested nanohybrid, and places its profile in the context of its class. Methods: A structured search of PubMed and the Cochrane Library with manual reference screening was performed; no formal risk-of-bias or certainty-of-evidence assessment was undertaken. Original in vitro and clinical studies were screened against predefined PICO-oriented criteria and synthesised qualitatively. Results: Twenty-seven studies were included, twenty-six in vitro and one clinical. The material was consistently described as a multicomponent dimethacrylate matrix reinforced with a bimodal zirconia and silica filler system at approximately 82 percent by weight, a configuration linked to high early flexural strength, elevated surface hardness, and favourable polishability. Artificial ageing reduced microhardness by roughly 16 to 24 percent and increased wear, three-point flexural strength fell below the ISO 4049 minimum after thirty days of ageing in artificial saliva, and low-pH and oxidative challenges degraded gloss and colour. Clinical data were limited to a single eighteen-month trial reporting high retention with more frequent transient postoperative sensitivity. Conclusions: The laboratory evidence indicates favourable early physicomechanical and esthetic behaviour that is sensitive to hydrolytic ageing and to polymerisation quality; clinical evidence rests on one short-term trial, so statements about clinical suitability are preliminary.

Purpose: Haptic and mixed-reality (MR) simulation technologies are increasingly used in preclinical dental education to support psychomotor skill acquisition and to reduce early patient exposure. This technical feasibility study aimed to develop a patient-specific digital twin patient model integrated into an MR haptic-based dental simulator and to explore dental students’ perceptions of it through an exploratory post-workshop survey. Materials and Methods: A digital twin patient model was created by integrating intraoral, facial, and cone-beam computed tomography (CBCT) datasets, and was implemented within the SIMtoCARE Dente haptic-based dental simulator (SIMtoCARE B.V., Vreeland, The Netherlands). In this single-centre pilot study, students completed a structured questionnaire assessing usability, perceived fidelity, and curricular relevance on the same day, following a single faculty-led workshop. Of the 50 students who attended, 41 completed the questionnaire (response rate: 82%). Results: The proposed workflow enabled the creation and implementation of the digital twin patient model. Students reported high acceptance and perceived educational value, with 92.7% supporting curricular integration. Prior exposure to haptic systems did not differ across demographic groups. Fourth-year respondents showed significantly higher agreement with the item on complementarity with conventional training. Conclusions: The digital twin patient model was positively perceived by dental students in this single-centre pilot study. These findings reflect immediate self-reported perceptions and require validation in larger, comparative and longitudinal studies.

Objectives. To describe the shade distribution and regional colour variation in a cohort of dental students and to quantify the agreement and shade-designation-derived colour difference between the VITA Easyshade V (VITA Zahnfabrik H. Rauter GmbH & Co. KG, Bad Saeckingen, Germany) spectrophotometer and the 3Shape TRIOS 5 (3Shape A/S, Copenhagen, Denmark) intraoral scanner at the cervical, middle and incisal thirds of the maxillary right central incisor, in both the VITA Classical and VITA 3D-Master systems. Methods. Tooth 11 was measured in 146 dental students with both devices at the three regions, the middle third serving as the representative body shade. The primary agreement outcome was the quadratic-weighted kappa of the Classical body shade, complemented by the paradox-robust Gwet AC1 and Brennan–Prediger coefficients; colour differences were obtained from published tab coordinates and not from coordinates measured on the teeth. Results. For the body shade (n = 144 teeth with an interpretable Classical designation from both instruments), exact agreement was 25.0% and Cohen’s kappa was near zero, the shades having clustered in a few light tabs. The primary outcome, the quadratic-weighted kappa, was 0.20 (95% confidence interval 0.09 to 0.34), with Gwet’s AC1 0.21 (0.12 to 0.27), Brennan–Prediger 0.19 (0.10 to 0.26) and an intraclass correlation coefficient, ICC(3,1), of 0.22 (0.03 to 0.39), none of them better than fair, and agreement on the 3D-Master lightness group was lower still. The scanner read lighter than the spectrophotometer by a mean of 1.80 value-ordered Classical units (Wilcoxon signed-rank p < 0.001) and by close to one lightness group on 3D-Master, and the two instruments distributed the shades differently at every region in both systems (Stuart–Maxwell p < 0.001). The scanner assigned a bleached 3D-Master shade in at least one region in 16.4% of participants against 1.4% for the spectrophotometer. On the Classical scale, agreement was weakest at the incisal third (Cohen’s kappa −0.03, quadratic-weighted kappa 0.03, Spearman 0.07, p = 0.42), where the mean signed difference was the smallest of any region, −0.39 units, and the dispersion the widest, with a mean absolute difference of 2.96 units and a standard deviation of 3.98 units. Colour varied across the three regions with both devices (Friedman p < 0.001), and the colour difference implied by the assigned tabs was above the 1.8-unit CIEDE2000 acceptability threshold for most tab pairs, carried by the lightness axis. Conclusions. The two instruments are not interchangeable. The scanner reads teeth as systematically lighter, most clearly at the cervical third and, on the Classical scale, least reliably at the incisal third, so a single device should be used throughout a case. With no independent reference standard, these data describe agreement and relative bias rather than accuracy. The scanner remains convenient for digital shade communication provided its lighter bias is taken into account.

The rapid adoption of vat photopolymerization (3D printing) in restorative and prosthetic dentistry has outpaced the independent biological characterization of the dimethacrylate resins on which it relies, even though incompletely converted networks can release residual monomers that are cytotoxic to the adjacent oral tissues. This study reports a qualitative in vitro cytotoxicity screening of three commercial photopolymer resins optimized for additive manufacturing: a general-purpose resin (ANYCUBIC) and two resins with a declared dental indication (TEMP PRINT and V-PRINT) performed according to the morphological evaluation described in ISO 10993-5. Aqueous extracts were prepared following ISO 10993-12 and applied to normal human fibroblasts (BJ line, ATCC CRL-2522) at 100% and 50% concentration for 24 h; morphological reactivity was graded on the standardized 0–4 scale by inverted light microscopy against an unexposed control, and supported by a semi-quantitative visual estimate of the proportion of affected cells. All three materials produced a concentration-dependent response. TEMP PRINT retained the best cellular compatibility (grade 1 at 50%, grade 2 at 100%), V-PRINT was intermediate, and ANYCUBIC showed the most pronounced reactivity (approaching grade 3 at 100%), giving an estimated cytotoxicity order of ANYCUBIC > V-PRINT > TEMP PRINT. As a qualitative morphological screening, the findings indicate that the dental-grade resins elicited a milder fibroblast response than the general-purpose photopolymer and support the recommendation that general-purpose resins should not be substituted for certified materials in intraoral use. Confirmation by quantitative viability assays with independent replicates is required before firm conclusions are drawn. In line with the qualitative nature of ISO 10993-5 morphological screening, the reported proportions of morphologically affected cells represent visual scoring rather than direct measurements of cell viability, and the study is therefore presented as an initial biological screening.

Objective: This study compared the color stability of three photopolymerizable resins (Anycubic Bio Resin White, V-Print c&b temp, GC Temp Print) after immersion in artificial saliva at 37 °C. Materials and Methods: Thirty-six disc specimens (10 mm × 1.5 mm) were printed on a Planmeca Creo C5 LCD printer and divided into control (T0), 24 h (T24), and 72 h (T72) groups (n = 4). CIELAB coordinates were measured spectrophotometrically, and ΔE was calculated using the CIE76 formula. Results: Material was the dominant factor for all color parameters (η²p = 0.774–0.964, all p < 0.001), while immersion time was not significant (all p > 0.05). Mean ΔE at T24/T72 was 0.90/0.66 (Anycubic), 2.25/3.79 (VOCO), and 4.48/3.58 (GC). The Kruskal–Wallis test detected an overall difference among materials at T72 (H(2) = 7.423, p = 0.024); however, no pairwise comparison remained significant after Bonferroni correction. At T24, one of four Anycubic specimens exceeded the perceptibility threshold (ΔE = 1.2), whereas 75% of GC Temp Print specimens exceeded the clinical acceptability threshold (ΔE > 3.7). Conclusions: Material composition was the primary determinant of chromatic behavior; resin selection remains critical for the aesthetic performance of 3D-printed provisional restorations.

Background/Objectives: Private dental markets operating under fee-for-service arrangements lack the structural accountability mechanisms that typically drive quality governance adoption in publicly funded systems. In Romania, where no private dental office currently holds formal accreditation, accreditation-seeking reflects a genuine behavioral choice rather than a regulatory compliance. This study examined whether financing structure and Professional Governance behavior operate as distinct determinants of accreditation-seeking intention among private dental practitioners and which pathway offers a more tractable entry point for quality policy intervention. Methods: A cross-sectional survey was conducted among 98 licensed private dental practitioners in Romania (November 2025–January 2026). Three domain composites were derived from a 31-item de novo instrument anchored in JCI, ANMCS, and EN ISO 9001:2015 standards: Professional Governance, Patient Rights and Ethics, and Patient Safety Behaviors. The financing profile was operationalized as engagement with the national public insurance system (CNAS). Binary logistic regression modeled high accreditation-seeking intention (Q31 ≥ 4) against standardized domain scores and financing engagement, with bootstrap confidence intervals from 2000 replicates. Results: Two predictors independently and significantly predicted high accreditation-seeking intention. CNAS engagement showed the strongest association (OR = 5.05, 95% bootstrap CI [1.87–17.91], and p = 0.003), while the Professional Governance score remained independently associated (OR = 2.68, 95% bootstrap CI [1.63–5.63], and p = 0.003). The Patient Rights and Ethics score was not significant. Practitioners actively exploring CNAS contracting showed the highest accreditation-seeking intention (exceeding that of established contractors), suggesting a possible transitional accountability dynamic during financing transition, though this interpretation requires prospective longitudinal validation. Model performance was good (AUC = 0.788; Nagelkerke R² = 0.339). Conclusions: Both financing engagement and governance behavior predicted accreditation-seeking intention after mutual adjustment, representing distinct pathways to voluntary quality adoption in private dental practice. Policy interventions aligned with entry into public contracting and with practice-level governance development are more likely to support accreditation uptake than normative appeals to professional ethics alone.

Orofacial pain (OFP) includes a broad spectrum of odontogenic and non-odontogenic conditions with overlapping clinical features that often limit diagnostic accuracy, driving increasing interest in artificial intelligence (AI) as a tool to enhance diagnostic precision and support clinical decision-making. A narrative review was conducted using PubMed/MEDLINE, Scopus, and Web of Science to identify studies (2016–2026) applying AI to the diagnosis, classification, or prediction of OFP in adults. Eligible studies reported at least two diagnostic performance metrics and were thematically grouped into odontogenic and non-odontogenic categories, the latter including musculoskeletal, neurovascular, and neuropathic pain. Twenty studies were included. Neurovascular pain, particularly migraine, showed the most consistent and highest diagnostic performance, likely due to the greater availability of structured clinical data and standardized diagnostic criteria. Musculoskeletal pain, especially temporomandibular disorders, also demonstrated high and reproducible performance. In contrast, odontogenic pain showed lower and more heterogeneous performance, with better results mainly in imaging-based models, while signal- and behavior-based approaches were less robust. Neuropathic pain exhibited moderate to high performance in selected radiomics studies, but overall results remained inconsistent due to phenotypic variability and limited objective biomarkers. Currently, AI shows promising potential in OFP diagnosis, especially for neurovascular and musculoskeletal pain, but clinical translation is limited by data heterogeneity and lack of validation. Progress in clinical practice depends on multimodal datasets and multicenter studies to ensure robust, generalizable tools.

Background: Intraoral scanning (IOS) errors seldom originate from a single-point failure; instead, they arise from interactions among hardware performance, reconstruction software, and operator-dependent acquisition behaviors. James Reason’s layered defense (Swiss-cheese) model provides a systems-oriented lens to trace how residual vulnerabilities can propagate into clinically relevant surface distortions. Objectives: To quantify within-scanner precision of IOS under repeatability conditions in a controlled in vitro setting and to propose a Reason-based framework that maps defensive layers, barriers, and residual failure modes along the IOS workflow. Methods: A controlled in vitro design was implemented to minimize clinical confounders. A standardized partially edentulous maxillary reference specimen was scanned repeatedly with three IOS systems under fixed environmental conditions using a standardized scanning strategy. Within each IOS, precision was quantified from repeated scans using surface deviation metrics, including root mean square (RMS) deviation, percentile-based dispersion, and the percentage of points within a predefined tolerance band. Residual vulnerabilities were organized into a systems-oriented error framework by defensive layer (hardware, software/processing, and acquisition/operator) and workflow stage (pre-scan preparation, acquisition, reconstruction/registration, and export/verification). Results: Deviation-based precision metrics revealed scanner-specific dispersion patterns, including differences in RMS magnitude and tail behavior (percentile spread), suggesting scanner-specific patterns of residual distortion under the tested conditions. Tolerance-based metrics further showed that threshold selection materially influences interpretability and perceived clinical relevance. In vitro IOS precision assessed under repeatability conditions should be interpreted as an emergent output of multiple interacting defensive layers rather than as the isolated performance of a single component. Coupling deviation-based precision metrics with Reason’s layered defense model yields a clinically actionable framework for quality control, helping anticipate where residual risk is most likely to accumulate and where mitigation checkpoints can be implemented. Conclusions: In vitro IOS repeatability should be interpreted as an emergent output of multiple interacting defensive layers rather than the isolated performance of a single component. Coupling repeatability metrics with Reason’s layered defense model supports a framework for quality-oriented interpretation, helping anticipate where residual risk is most likely to accumulate and where mitigation checkpoints can be implemented.

Background/Objectives: This study aimed to compare AI-generated educational material with faculty-authored content in Dental Prostheses Technology, evaluating perceived clarity, accuracy, structure, usefulness, and overall instructional quality across different age and professional groups. Methods: An analytical cross-sectional study was conducted using two versions of the first three chapters of a prosthodontics textbook: the original faculty-authored text and a reformulated version generated by ChatGPT 5.2 (OpenAI). Images were removed and formatting standardized to ensure a text-only comparison. An anonymized online questionnaire based on a five-point Likert scale assessed clarity, accuracy, readability, usefulness and structure. To reduce potential bias, participants were unaware of the authorship of the evaluated materials (human-authored vs. AI-generated). A total of 130 participants independently reviewed both documents. Data were analyzed using Wilcoxon signed-rank, Mann–Whitney U, and Friedman tests. Results: Both materials received favorable evaluations across all dimensions. The AI-generated version demonstrated a statistically significant advantage in clarity (Z = −2.107, p = 0.035; r = 0.19), while no significant differences were observed for structure, accuracy, readability, or usefulness. Generational differences emerged: younger participants valued improved clarity but reported reduced usefulness, mid-career participants showed the greatest improvement in perceived accuracy, and senior professionals reported substantial gains in usefulness and readability. Conclusions: AI-generated educational material demonstrates pedagogical equivalence to faculty-authored content, with clarity representing its principal advantage. Large language models may serve as effective complementary tools in dental education, particularly for restructuring complex content.

In the continuous development of additive technologies and light-sensitive resins, the biological performance of 3D-printed resins is strongly dependent on photopolymerization efficiency and post-processing conditions. This study evaluated the effect of post-curing duration on the cellular response to two denture base resins using direct contact and indirect eluate-based pathways. Human gingival fibroblasts were assessed through viability, membrane integrity, nitric oxide production, fluorescence live/dead staining, and caspase-3/7 activity. As a result of contact between the cells and the surface interface of the specimen disks, reduced metabolic activity was noticed compared with the control under direct exposure, indicating cellular stress. Extended polymerization has been demonstrated to improve metabolic activity and reduce apoptotic signals for the V-Print dentbase resin, whereas FotoDent Denture presented a less uniform response under the same parameters. Therefore, for evaluating the cytotoxicity of light-sensitive resins, it is not sufficient to assess only the saliva-soluble substances released from the resin, such as residual monomers, but also the 3D printing parameters.