Search Results (546)

Advancements in Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) have promoted the development of novel dental materials for several types of definitive restorations. The aim of this study was to evaluate the surface characteristics of resin-based CAD/CAM restorative materials, fabricated using both subtractive and additive manufacturing techniques. The materials tested included Filtek Z550 (FZ), Vita Enamic (VE), Shofu HC (SH), and VarseoSmile TriniQ (TQ). For each material, 24 specimens were prepared; half were manually polished following the manufacturer’s recommendations, while the other half underwent standardized metallographic polishing. The surface roughness, wettability, and molecular composition were assessed. A statistical analysis was performed using IBM SPSS 29.0 at a 95% confidence level (α = 0.05). Statistically significant differences in surface properties were observed between direct and indirect restoratives following manual polishing, with SH performing favorably in terms of surface roughness. The polishing method significantly influenced the surface characteristics of each material, except for certain roughness parameters in SH. Both surface roughness and wettability were dependent on the material and the polishing technique, highlighting the need for improved material-specific polishing protocols. Full article

Identifying the most reactive conformation of a molecule is a central challenge in computational chemistry, particularly when reactivity depends on subtle conformational effects. While most conformation search tools aim to find the lowest-energy structure, they often overlook the electronic descriptors that govern chemical reactivity. In this work, we present GAELLE, a cheminformatics tool that combines conformer generation with quantum reactivity descriptors to identify the most reactive structure of a molecule in solution. GAELLE integrates an evolutionary algorithm with fast semiempirical quantum chemical calculations (xTB), enabling the automated ranking of conformers based on HOMO–LUMO gap minimization (Pearson’s principle of maximum hardness) and electrophilicity index (Parr’s electrophilicity scale). Solvent effects are accounted for via implicit solvation models (GBSA/ALPB) to ensure realistic evaluation of reactivity in solution. The method is fully SMILES-driven, open-source, and scalable to medium-sized drug-like molecules. Applications to reactive intermediates, bioactive conformations, and pre-reactive complexes demonstrate the method’s relevance for mechanism elucidation, molecular design, and in silico screening. GAELLE is publicly available and offers a reactivity-focused alternative to traditional energy-minimization tools in conformational analysis. Full article

This paper investigates the effectiveness of Word2Vec-based molecular representation learning on SMILES (Simplified Molecular Input Line Entry System) strings for a downstream prediction task related to the market approvability of chemical compounds. Here, market approvability is treated as a proxy classification label derived from approval status, where only the molecular structure is analyzed. We train character-level embeddings using Continuous Bag of Words (CBOW) and Skip-Gram with Negative Sampling architectures and apply the resulting embeddings in a downstream classification task using a multi-layer perceptron (MLP). To evaluate the utility of these lightweight embedding techniques, we conduct experiments on a curated SMILES dataset labeled by approval status under both imbalanced and SMOTE-balanced training conditions. In addition to our Word2Vec-based models, we include a ChemBERTa-based baseline using the pretrained ChemBERTa-77M model. Our findings show that while ChemBERTa achieves a higher performance, the Word2Vec-based models offer a favorable trade-off between accuracy and computational efficiency. This efficiency is especially relevant in large-scale compound screening, where rapid exploration of the chemical space can support early-stage cheminformatics workflows. These results suggest that traditional embedding models can serve as viable alternatives for scalable and interpretable cheminformatics pipelines, particularly in resource-constrained environments. Full article

Before colonization, Indigenous child protection looked like an interdependent community. Indigenous knowledges and relational actions kept all within its fold safe and well. Colonial dispossession of land, degradation of subsistence rights, boarding schools, ongoing child removal, capitalism, and systems of oppression attempted to disconnect Indigenous peoples from their language, lands, ceremonial practices, stories, dances, songs, family, community, and themselves. However, Indigenous communities have held on, persevered, and have begun to turn the tide of intergenerational trauma through the revival of Indigenous wellness and self-determination. We believe local-based Indigenous relational knowledges can end colonial harm and promote wellbeing for all families and children. Our work builds off an Indigenous Connectedness Framework that recognizes the importance of the interrelated wellbeing of a person, family, community, ancestors/future generations, and the Earth. This framework was adapted based on community feedback to better fit the Nome Eskimo Community (NEC) and Bering Strait regional context. This paper shares results of community focus groups that led to the creation of a NEC Piaġiq (wellness) Framework, and shares intentions for pilot implementation of a wellness curriculum and pilot intervention. We will offer insights and lessons learned. We believe self-determined Indigenous wellbeing efforts can lead to improved outcomes for our sacred children and families for generations to come. Full article

Background/Objectives: Impacted teeth are characterized by having more than three-quarters of root development completed, however failing to erupt or demonstrate imminent eruption, as evidenced both by clinical and radiographic evaluation. Canine impaction is an entity of clinical significance considering its potential to affect both oral function and facial aesthetics. If not appropriately managed, this condition may adversely impact functional occlusion and structural smile integrity. The purpose of the study was to investigate the prevalence of impacted and transmigrant canines in a Greek orthodontic cohort and identify potential sex-based differences. Methods: A total of 2594 panoramic radiographs and clinical records of consecutive patients in the mixed and permanent dentition stages, treated at the Department of Orthodontics of the Aristotle University of Thessaloniki, Greece, were retrospectively retrieved and analyzed to detect the presence of impacted and transmigrant canines. Patients lacking complete clinical records or panoramic radiograph, undergoing or had undergone orthodontic treatment, or presenting conditions affecting normal permanent dentition development, including pathological conditions, cleft lip and palate or hereditary disorders, were excluded. Results: At least one impacted canine was detected in 109 patients (67% females, 33% males), with a median age of 15 years (IQR: 13–18), documenting a 4.2% prevalence (6.97% females, 2.32% males). The frequency of maxillary canine impaction was 3.97%, while in the mandible a frequency of 0.46% was reported. The frequency of bilateral canine impaction was 1%, with it being present in 25.7% of patients with canine impaction. The prevalence of transmigrant canines was 0.11%, with detection solely in the mandible. A statistically significant sex difference was detected solely in the prevalence of impaction. Conclusions: Considering the implications of canine impaction, the epidemiological investigation of this entity may facilitate an early diagnosis and treatment. Full article

Background/Objectives: The management of immature teeth with wide apical foramina presents significant challenges in endodontic treatment due to difficulties in achieving a hermetic seal. The aim of this study was to evaluate void formation in apical plugs created using three calcium silicate-based materials—Biodentine, NuSmile NeoPUTTY, and Well-Root PT—applied with the help of manual, ultrasonic, or rotary file condensation (XP-endo Shaper) in 3D-printed immature teeth. Methods: Micro-computed tomography analysis was used to assess the internal, external, and total void percentage of material volume. The statistical analysis was performed using two-way ANOVA and the post hoc Bonferroni test. Statistical significance was set at p < 0.05. Results: The materials and techniques used individually do not significantly influence the formation of internal voids, but their combination does (F(4, 99) = 2.717, p = 0.034). Both factors and their interaction are significant for external voids (F(4, 99) = 4.169, p = 0.004), and all have a notable effect on total void percentages (F(4, 99) = 3.456, p = 0.012). No significant differences were observed in internal voids across the groups (p > 0.05), ranging from 0.635% to 1.078%. External voids varied significantly, with Well-Root PT and ultrasonic condensation showing the highest values with a significant difference (p < 0.05), while NeoPUTTY and Biodentine with XP-endo Shaper exhibited the lowest. Total voids remained below 4%, with no significant differences among manual condensation groups. Neither material type nor application technique consistently influenced void formation, except for Well-Root PT with ultrasonic condensation. Conclusions: These findings suggest that modern bioceramic materials and application techniques produce comparable, low-void apical plugs, with XP-endo Shaper showing promise for minimizing external voids. The interaction between material and application technique plays a crucial role during the creation of apical plugs. Full article

Background/Objectives: There are many commercial mouthrinses, used for a variety of purposes, including antiseptic activity. The objective of this study was to determine the antibacterial activity of various TheraBreath™ oral rinses against the cariogenic bacterium, Streptococcus mutans, and saliva-derived microbial communities, and their antibiofilm activity against S. mutans in vitro biofilms. Methods: Bactericidal activity against planktonic S. mutans was assessed by colony counting after 30 and 2 min exposures to mouthrinses. Ten saliva samples were exposed to mouthrinses for 30 s and plated aerobically on blood agar and Mitis Salivarius agar. Mature biofilms of S. mutans were treated with mouthrinses for 15 min followed by fluorescent vitality staining and polysaccharide measurement, followed by crystal violet staining for measurement of total biofilm remaining. Statistical analysis was performed using Kruskal–Wallis with Dunn’s multiple comparisons test comparing all mean ranks (α = 0.05). Results: TheraBreath™ Fresh Breath, Healthy Smile, and Dry Mouth exhibited no significant antibacterial activity. TheraBreath™ Healthy Gums showed antibacterial activity against S. mutans and microbes from saliva samples similar to Listerine^® Naturals at all exposure times. Whitening Fresh Breath showed intermediate killing of S. mutans after 30 min in liquid but not after 2 min or against salivary microbes. Live/Dead fluorescence vitality staining showed that Healthy Gums and Whitening Fresh Breath had antibacterial activity against mature biofilms of S. mutans statistically similar to Listerine^® Naturals and Colgate^® Total; however, Whitening Fresh Breath did not have significant killing compared to PBS. Conclusions: TheraBreath™ Healthy Gums demonstrated similar antiseptic activity levels to other antiseptic-claiming commercial rinses. Whitening Fresh Breath was comparable but unable to kill in short exposure times. Full article

The use of orthodontic aligners has increased significantly due to their convenience and esthetic advantages. However, understanding their microbiological behavior and cytotoxicity is essential. This study aimed to evaluate the metabolic activity (MA) and proliferation of different bacterial strains—assessed through colony-forming unit (CFU) counts—as well as the cytotoxicity of three widely used aligner systems: Spark, Invisalign, and Smile. Wettability and surface free energy (both dispersive and polar components) were determined using the sessile drop technique. The bacterial strains Streptococcus oralis, Actinomyces viscosus, Streptococcus gordonii, Enterococcus faecalis, and Porphyromonas gingivalis were cultured, and their behavior on the aligner surfaces was assessed under simulated oral cavity conditions in both aerobic and anaerobic environments using a bioreactor. Cytocompatibility was evaluated with HFF-1 human fibroblasts. Distinct strain-specific behaviors were observed. For Spark aligners, the contact angle was 70.5°, Invisalign 80.6°, and Smile 91.2°, and the surface free energy was 60.8, 66.7, and 74. 2 mJ/m², respectively, highlighting the high polar component of the Spark aligner of 31.9 mJ/m² compared to 19.3 and 20.2 mJ/m² for Invisalign and Smile, respectively. The Spark aligner exhibited the lowest metabolic activity for Streptococcus oralis (23.1%), Actinomyces viscosus (43.2%), Porphyromonas gingivalis (17.7%), and biofilm formation (2.4%), likely due to its higher hydrophilicity. The Smile aligner showed the lowest metabolic activity for Streptococcus gordonii (23.6%) and Enterococcus faecalis (51.1%), attributed to its low polar surface free energy component. CFU counts were minimal for all aligners and bacterial strains, including biofilm. All aligners demonstrated cytocompatibility above 70% (Spark: 71.0%, Invisalign: 75.7%, and Smile: 75.6%). These findings highlight the importance of considering aligner material properties in clinical practice and underscore the need for proper oral hygiene and aligner maintenance. Full article

Background: The present study investigated the relation between dental inclination, colorimetric variation, and aesthetic perception according to the modification of incisor inclination. Smile aesthetics, shaped by morphological factors and patient perception, are vital for social attractiveness and treatment success. This study aimed to assess the effect of varying head tilt on the perceived colour of upper central incisors by simulating changes in torque of the tooth, as well as evaluate factors influencing the perception of an aesthetic smile, including morphological characteristics and gingival aesthetic parameters. Methods: The study was comprised of three stages: colour analysis, evaluation of micro- and mini-aesthetic smile features, and an image-based assessment to determine evaluator perceptions and overall smile attractiveness. A sample of 50 students with complete, lesion-free anterior dentition was analysed. To simulate the effect of orthodontic torque changes during colour analysis, subjects tilted their heads downward and upward, representing palatal and buccal crown torque, respectively. Standardized macro-intraoral photographs were captured under controlled lighting conditions using a DSLR camera stabilized on a tripod in the different positions: the neutral head position (p0), 15° upward (p + 15), and 15° downward (p − 15). Digital colour analysis was conducted in the CIELAB colour space (L*, a*, b*). In the next stage, focusing on micro- and mini-aesthetic evaluation, an additional 50 smiles were generated using artificial intelligence via the SmileCloud program—one digitally enhanced smile per subject—complementing the initial set of 50 spontaneous smiles. These 100 smile images were evaluated by 50 laypersons and 50 dentists using a visual analogue scale via an online questionnaire, in order to assess perceptions, determine smile attractiveness, and quantify gingival aesthetic parameters. Results: The statistically significant regression results are as follows: those for the L* values in all three head inclinations: downward (−15 degrees), upward (+15 degrees), and total tilting (−15 to +15 degrees), as well as for the a* values for downward tilting and the b* values for total tilting. When the head is tilted downwards, the central incisors are positioned retrusively, and the L* b* values reveal a darker and more yellowish appearance, whereas, with the head tilted upwards, the central incisors protrude, and L* a* values indicate a brighter and more greenish appear. In the evaluation stage of the smile aesthetics study, no significant differences were observed in the judgments between laypersons and dentists or between males and females. Smiles with a high or average anterior line, parallel arc, upward lip curvature, visible first/second premolars, a smile index of 5.08–5.87, and symmetry score of 1.04 were rated as more attractive. Significant asymmetries were observed between upper dental hemi-quadrants in gingival contour and interdental papilla height, highlighting subtle morphological variations relevant to smile aesthetics. Conclusions: Aesthetic assessment revealed that the findings suggest a measurable impact of head position on dental colour perception and aesthetic evaluation. Evaluator variables including profession and gender exerted negligible effects on aesthetic perception, whereas smile attractiveness features and gingival aesthetic parameters demonstrate significant clinical applicability in patient management. Full article

Aligners represent a therapeutic option in orthodontics, offering advantages such as aesthetics, comfort, and individualized prescriptions for each patient. However, the predictability of maxillary expansion is subject to variability. The objective of this article is to evaluate the efficacy and predictability of aligners in maxillary expansion. One hundred adult patients were included in this study, divided into four groups, each assigned to a different brand of clear aligners: Angel Aligners, Invisalign, Spark, or HeySmile. Digital models were obtained at three stages: initial STL (T1), prediction (T2), and final (T3) (before the first refinement). The models were measured to obtain linear distances between canines, first bicuspids, second bicuspids, and first molars. Statistical analysis was performed using SPSS 28.0. The best predictability was obtained in the lower arch (68.900%) for second bicuspids, while the worst accuracy was for canines (39.290% in the upper arch using Invisalign). Angel aligner showed the highest percentage of predictability (60.002%) among the evaluated brands, followed by HeySmile (59.895%), Spark (59.275%), and Invisalign (57.153%). The results show that clear aligners are an effective treatment for transverse movements in both arches. However, further research is needed to improve predictability. Full article

Biomimetic restorative treatments in pediatric dentistry increase the longevity of the restoration compared to traditional methods and aim to preserve the natural tooth structure. Prefabricated zirconia crowns have been developed as aesthetic alternatives to stainless steel crowns for full-coronal restorations of primary teeth. This study aimed to compare the fracture resistance and microleakage of two different posterior zirconia crown brands—NuSmile^® (USA) and ProfZrCrown^® (Turkey)—cemented with either conventional glass ionomer cement (GIC) or resin-modified glass ionomer cement (RMGIC). Eighty extracted primary molars were divided into four groups (n = 20). Crowns were cemented with Ketac™ Cem Radiopaque (GIC) or Ketac™ Cem Plus (RMGIC), in accordance with the manufacturers’ instructions, and then subjected to thermocycling. Fracture resistance was tested on 40 samples by applying an increasing compressive load until failure, with values recorded in Newtons (N). The remaining 40 samples were immersed in basic fuchsin dye for microleakage testing and evaluated under a stereomicroscope at 30× magnification. The results revealed that the ProfZrCrown^®/RMGIC group exhibited significantly higher fracture resistance compared to the NuSmile^®/RMGIC group (p < 0.05). No statistically significant differences were found among the other groups. Although no significant differences in microleakage were observed among the groups (p > 0.05), crowns cemented with GIC demonstrated higher microleakage levels. Within the limitations of this in vitro study, ProfZrCrown^® may be considered a promising alternative for aesthetic posterior restorations in pediatric dentistry. Full article

Background: Immediate implant therapy is a highly effective solution for replacing non-restorable teeth, particularly in the esthetic zone, where achieving optimal results can be challenging. In this area, even small imperfections can significantly affect a patient’s satisfaction due to the high visibility of the teeth involved. This narrative review provides an overview of findings from case reports and systematic reviews that highlight the success of immediate implant therapy in the esthetic zone. Additionally, it includes a case illustration to emphasize how meticulous planning, combined with advanced techniques, can achieve successful outcomes. Methods: A comprehensive literature review was conducted to evaluate the effectiveness of immediate implant placement and loading for non-restorable teeth in the esthetic zone. Key factors identified for success include atraumatic tooth extraction, precise implant placement, and effective soft tissue management to achieve natural esthetics and long-term stability. To illustrate these principles, the review features a clinical case involving the replacement of a maxillary right central incisor rendered non-restorable due to trauma. Treatment incorporated advanced digital planning, atraumatic extraction, immediate implant placement, and provisionalization. The final restoration involved soft tissue contouring and ceramic veneers on adjacent teeth, enhancing the patient’s overall smile and confidence. Results: Evidence from the literature indicates that well-planned immediate implant therapy achieves high success rates and long-term stability. In the clinical case presented, the workflow met the patient’s esthetic and functional needs, resulting in a natural, harmonious smile, and improved patient satisfaction. Conclusions: Immediate implant therapy in the esthetic zone is highly effective when critical considerations—such as bone preservation, guided implant placement, soft tissue shaping, and appropriate restoration—are meticulously addressed. Advanced techniques and careful planning are essential for fulfilling both esthetic and functional patient needs, ultimately delivering predictable and successful outcomes. Full article

The integration of artificial intelligence (AI) and advanced digital workflows is revolutionising full-arch implant dentistry, particularly for geriatric patients with edentulous and atrophic arches, for whom achieving both prosthetic passivity and optimal aesthetic outcomes is critical. This narrative review evaluates current challenges in intraoral scanning accuracy—such as scan distortion, angular deviation, and cross-arch misalignment—and presents how innovations like the Medit SmartX AI-guided workflow and the Scan Ladder system can significantly enhance precision in implant position registration. These technologies mitigate stitching errors by using real-time scan body recognition and auxiliary geometric references, yielding mean RMS trueness values as low as 11–13 µm, comparable to dedicated photogrammetry systems. AI-driven prosthetic design further aligns implant-supported restorations with facial symmetry and smile aesthetics, prioritising predictable midline and occlusal plane control. Early clinical data indicate that such tools can reduce prosthetic misfits to under 20 µm and lower complication rates related to passive fit, while shortening scan times by up to 30% compared to conventional workflows. This is especially valuable for elderly individuals who may not tolerate multiple lengthy adjustments. Additionally, emerging AI applications in design automation, scan validation, and patient-specific workflow adaptation continue to evolve, supporting more efficient and personalised digital prosthodontics. In summary, AI-enhanced scanning and prosthetic workflows do not merely meet functional demands but also elevate aesthetic standards in complex full-arch rehabilitations. The synergy of AI and digital dentistry presents a transformative opportunity to consistently deliver superior precision, passivity, and facial harmony for edentulous implant patients. Full article

We study the shape of the Bachelier-implied volatility of a spread option on two assets following correlated local volatility models. This includes the limiting case of spread options on two correlated Black–Scholes (BS) assets. We give an analytical result for the at-the-money (ATM) skew of the spread-implied volatility, which depends only on the components’ ATM volatilities and skews. We also compute the ATM convexity of the implied spread option for the case when the assets follow correlated BS models. The results are extracted from the short-maturity asymptotics for basket options obtained previously by Avellaneda, Boyer-Olson, Busca and Friz and, thus, become exact in the short-maturity limit. Numerical testing of the short-maturity analytical results under the Black–Scholes model and in a local volatility model show good agreement for strikes sufficiently close to the ATM point. Numerical experiments suggest that a linear approximation for the spread Bachelier volatility constructed from the ATM spread volatility and skew gives a good approximation for the spread volatility for highly correlated assets. Full article

Variable selection (VS) is a critical step in developing predictive binary classification (BC) models. Many traditional methods for assessing the added value of a candidate variable provide global performance summaries and lack an interpretable graphical summary of results. To address this limitation, we developed the U-smile method, a residual-based, post hoc evaluation approach for assessing prediction improvements and worsening separately for events and non-events. The U-smile method produces three families of interpretable BA-RB-I coefficients at three levels of generality and a standardized graphical summary through U-smile and prediction improvement–worsening (PIW) plots, enabling transparent, interpretable, and explainable VS. Validated in balanced and imbalanced BC scenarios, the method proved robust to class imbalance and collinearity, and more sensitive than traditional metrics in detecting subtle but meaningful effects. Moreover, the method’s intuitive visual output (U-smile plot) facilitates the rapid communication of results to non-technical stakeholders, bridging the gap between data science and applied decision-making. The U-smile method supports both local and global evaluations and complements existing explainable machine learning (XML) and artificial intelligence (XAI) tools without overlapping in their functions. The U-smile method offers a transparency-enhancing and human-oriented approach for ethical and fair VS, making it highly suited for high-stakes domains, e.g., healthcare and public health. Full article