Search Results (901)

Background and Objectives: Periodontal health represents a condition characterized by homeostasis between the teeth and the surrounding supporting tissues and implies the absence of inflammation, confirmed by the lack of bleeding, epithelial attachment loss, mobility, or periodontal pocket formation. Fixed prosthetic restorations may compromise periodontal health already during the fabrication phase, given that decisions made during their planning and placement affect long-term clinical outcomes. The aim of this manuscript was to provide insight into the interaction between periodontal tissues and fixed prosthetic restorations. Materials and Methods: A narrative literature review was conducted using a structured search of the PubMed/MEDLINE, Scopus, and Google Scholar databases to identify studies addressing periodontal health in relation to fixed dental prostheses. The impacts of tooth preparation, gingival retraction methods, supracrestal tissue attachment, periodontal phenotype, crown emergence profile, and marginal fit of various biomaterials were analyzed. Results: According to the literature data, subgingival margin placement and violation of the supracrestal tissue attachment (biological width) induce chronic inflammation, loss of epithelial attachment, and alveolar bone resorption. Gingival retraction agents, used in chemomechanical retraction procedures, particularly ferric sulfate-based agents, may lead to a transient but significant spike in inflammatory markers and dysbiosis of the subgingival microbiome. Contemporary approaches, such as the biologically oriented preparation technique and the use of CAD/CAM (Computer-Aided Design and Computer-Aided Manufacturing) technology, may improve the precision of marginal fit. Zirconia restorations exhibit significantly better biocompatibility and reduced microbial adhesion compared to metal–ceramic restorations. Conclusions: Biological response of the periodontium to fixed prosthetic restorations depends on the complex interaction between the material, position of the marginal line, and oral hygiene control. Regardless of the material used or the fabrication technique employed, adequate plaque control and regular maintenance remain key factors in preserving periodontal health. Full article

Large language models (LLMs) frequently generate physically impossible parametric specifications in computer-aided design (CAD). This paper presents FMforME, a three-layer runtime constraint verification framework that integrates LLM-based generation with six engineering standard-grounded defect detection predicates (D1–D6) and execution in Autodesk Fusion 360. To address detected violations, a Self-Examine subsystem iteratively provides structured, standard-referenced feedback to the LLM, enabling verifier-guided error correction. We evaluated the framework across 564 test cases using four LLM backends from three model families. The system showed consistent buildability within the evaluated benchmark: across all models, every specification validated by the Monitor successfully built in Fusion 360 (548/548). Across the four evaluated backends, realized seeded defect detection ranged from 95.5% to 95.8%, and three backends showed an observed 100% natural pass rate in this benchmark. Crucially, this runtime safety barrier adds little computational overhead relative to LLM inference, averaging only 0.1 ms per in-memory verification check. These results show that standards-referenced runtime verification with structured self-correction can serve as a practical safeguard for LLM-generated CAD specifications within the tested single-part workflows, while broader validation on complex assemblies remains future work. Full article

Background: In the field of minimally invasive restorative dentistry, ultrathin (<0.5 mm thickness) ceramic occlusal veneers are increasing being used as alternatives to full-coverage crowns, particularly for mild occlusal wear and not deep caries. However, only limited research attention has been given to how marked reduction in the thickness of a veneer restoration affects its mechanical performance. The purpose of the present in vitro study was to compare the performance of restorations that comprised a 0.3 mm thick zirconia veneer to the case when a lithium disilicate veneer was used, under quasi-static compressive loading. Methods: Forty extracted human molars, without caries, cracks or fractures and with intact coronal structure, were randomly assigned to two groups: lithium disilicate occlusal veneers (n = 20) and zirconia occlusal veneers (n = 20). The teeth were embedded in acrylic resin up to the cementoenamel junction. Digital scans were used to record the original anatomy and guide restoration design. Standardized occlusal preparations were performed using a 0.3 mm reduction protocol and verified with silicone guides to support a biomimetic, tooth-preserving approach. After preparation, the teeth were rescanned, and restorations were designed and fabricated using CAD/CAM technology. Lithium disilicate restorations were milled from Ivoclar Porcelain System [IPS], esthetic maximized [e.max] computer-aided design [CAD] blocks, whereas zirconia restorations were milled from Prettau 3 zirconia discs. Restorations were adhesively cemented with dual-cure resin cement following material-specific surface treatment protocols. Fracture resistance was tested using a universal testing machine under compressive loading until failure. Results: The fracture loads with lithium disilicate and zirconia occlusal veneers were 481.45 ± 68.23 N and 720.93 ± 95.44 N, respectively. Fracture was catastrophic in lithium disilicate occlusal veneers whereas it was not so when zirconia veneer was used. Conclusion: Quasi-static compressive fracture load when a lithium disilicate veneer was used was significantly lower than when a zirconia veneer was used. Full article

This study presents a continuous geometric framework utilizing a novel quartic Overhauser (QOVR) spline with adjustable local parameters. The proposed spline is constructed as an alternative representation from an algebraic blending mechanism of three parabolic segments defined over a five-point control configuration. This structure enables flexible spline definitions through internal parametric knots without modifying the spatial locations of the control points. The resulting formulation maintains $C^1$ continuity, ensuring smooth transitions between adjacent spline segments. The QOVR spline offers structural advantages in interactive design and computational geometry environments. To evaluate the computational steps, a dedicated object-oriented prototyping framework was introduced to organize, visualize, and analyze the proposed spline. This arrangement facilitates continuous visualization, interactive adjustment of local parameters, and multi-segment implementations. Exported coordinates further allow independent numerical verification in external computational environments when required. The QOVR spline achieves a balance between geometric flexibility and boundary condition invariance. By allowing independent parametric knot adjustments without disrupting the global continuity constraints, the proposed design offers direct local morphological flexibility during geometric synthesis. This study introduces the QOVR spline integrated into an object-oriented prototyping framework, offering a distinct algebraic design for interactive geometric environments and computer-aided design (CAD) setups. Full article

Reverse engineering of printed circuit boards is still largely manual when original computer-aided design documentation is unavailable. This paper presents a semi-automatic vision-based pipeline that prepares an editable KiCad schematic draft for use in an Electronic Design Automation (EDA) workflow from paired TOP and BOTTOM board images. The method combines color-profile estimation, pad and through-hole detection, trace segmentation, optical character recognition, component inference, an explicit evidence graph and schematic export with drawn wires. A separate readability step aligns symbols to a grid and reroutes the reconstructed nets with orthogonal wires; it does not change the reconstructed netlist. The primary quantitative evaluation used twelve synthetic KiCad fixtures and three solver configurations: the default sequential pipeline, an opt-in global component solver and an opt-in probabilistic contact solver. These fixtures provide controlled regression cases and are complemented by a small exploratory acquisition trial on real photographed boards. All configurations completed all runs and passed the export round-trip validation without falling back to label-only connectivity. This round-trip check confirms consistency between the internal reconstruction and the exported schematic, but it is reported separately from electrical correctness against the KiCad reference design. The stricter reconstruction-quality criterion still failed on four stress cases involving repeated component chains, long meandering variable-width traces, circular distractors near pads and two-sided transistor layouts. The probabilistic contact solver was therefore kept as an opt-in diagnostic mode rather than enabled by default; it reduced the global pin-to-pin netlist edit distance from 642 to 525 while preserving schematic export checks. The real-board trial indicates that pad and hole detection can transfer to simple photographs, with trace extraction remaining sensitive to uncontrolled illumination and weak copper contrast. The results support the use of the system as a human-in-the-loop reconstruction assistant and identify component grouping, trace-contact reasoning, real-photograph benchmarking and safe missing-edge activation as the main remaining research problems. Full article

This study extended a previously established intraoral scanning (IOS) and optical coherence tomography (OCT) dual-modality monitoring workflow for computer-aided design/computer-aided manufacturing (CAD/CAM) restorations to three additional crown material classes alongside a resin composite (RECO) reference. Four material classes were investigated ($n=8$ each): RECO, polymer-infiltrated ceramic network (PICN), lithium disilicate ceramic (LDSC), and zirconia-reinforced lithium silicate ceramic (ZLSC). Monolithic crowns were adhesively luted to standardized human molar abutment teeth and aged by cyclic loading (50500$\mathrm{N}$, 2$\mathrm{Hz}$, 37 2${}^{\circ }\mathrm{C}$, up to 1250000 cycles) in a mouth-motion simulator. IOS and handheld OCT were performed at baseline and after every 250000 cycles under phantom-head conditions; correspondence was assessed using Spearman’s rank correlation coefficient (exploratory, uncorrected for multiple comparisons). OCT consistently showed higher defect extents than IOS across all material classes and timepoints. While no significant IOS-OCT associations were found for RECO and the PICN, OCT detected full-thickness vertical subsurface damage propagation from the earliest timepoint in LDSC and ZLSC, with IOS-derived surface wear remaining markedly lower. Surface-based monitoring alone did not reliably reflect subsurface damage propagation, a dissociation most pronounced in the vertical dimension and silicate-based materials. Intraoral OCT may provide complementary, non-invasive subsurface information to support individualized recall scheduling and minimally invasive repair decisions. Full article

This study aimed to quantitatively analyze giant slalom turn kinematics using a video-based three-dimensional computer-aided design (3D CAD) model-matching method. The analyzed skiers included the top five finishers (WT) and one top-ranked Japanese elite skier (JP). Broadcast competition footage was analyzed to estimate the ski edging angle, center of mass (COM) position, and knee joint and hip joint angle during the turning motion. One turn cycle was divided into five phases: neutral position (NP), edging start (ES), load start (LS), turn maximum (TM), and edging finish (EF). Phase durations and kinematic variables were compared descriptively. JP demonstrated a longer total turn duration than WT, particularly during the LS–TM phase. During the NP–ES phase, WT elevated the COM while simultaneously shifting it inward, whereas JP lowered the COM. JP demonstrated greater hip and knee flexion during the early turn phase compared with WT. This study demonstrates the feasibility of extracting quantitative kinematic information from broadcast competition footage using a 3D CAD model-matching approach. The findings suggest that differences in COM and lower-limb movements may reflect different turning movement strategies. Because only one Japanese elite skier was analyzed, the findings should be interpreted as exploratory observations and cannot be generalized to all Japanese alpine skiers. Full article

Engineering drawings are one of the most essential references in the product research and development process. With the rapid advancement of computer hardware and software, the presentation of engineering drawings has evolved from traditional hand-drafting to computer-aided design (CAD). However, in current practice, transforming 2D drawings into 3D models still requires manual operation in CAD software. This process is time-consuming, labor-intensive, and prone to errors if engineers misinterpret the drawings, which may result in defective models. To address this issue, this study employs the Darknet SDK (Software Development Kit) to train YOLO (You Only Look Once) models using 2D engineering drawings as training data. By performing image segmentation and classification of drawing features, seven feature-specific YOLO models were trained to detect: orthographic views (100%), geometric features (100%), convex/concave features (99.9%), dimension groups (99.8%), dimension lines (99.1%), theoretical dimensions (98.6%), and text characters (93.6%). These pretrained models are then used to extract dimensional and geometric information from 2D drawings. The corresponding dimensional values are matched with the relative size and edge lengths of detected objects in the images and stored in a relational database. Subsequently, Siemens NX CAD software, along with its NX Open secondary development modules, was integrated to convert the recognized 2D drawing features into 3D models. This approach reduces dimensional errors in 2D-to-3D model conversion, ensures the accuracy of feature recognition, and improves the efficiency of model generation. Full article

This article introduces a modified reverse scan technique for abutment teeth that incorporates laboratory scanners into a fully digital workflow to enhance accuracy and reduces the impact of stitching and merging errors associated with long-span intraoral scans when fabricating extensive tooth-supported prostheses. This cost-effective, time-saving, and versatile procedure uses a 3D-printed interim tooth-supported prosthesis that is sectioned, bonded intraorally, and scanned with a laboratory scanner to improve the virtual definitive cast. The modification is performed using free software. Full article

The growing adoption of prefabricated timber construction in Australia has highlighted persistent difficulties in integrating digital workflows between architectural design, structural engineering, and manufacturing. Although Building Information Modelling (BIM), Computer-Aided Design and Manufacturing (CAD/CAM), and Computer Numerical Control (CNC) technologies are increasingly used, fragmented software environments, inconsistent data exchange, and limited early manufacturer involvement continue to cause information loss, manual rework, and design-to-manufacturing workflow gaps. This study provides a PRISMA-informed structured review of design-to-manufacturing integration in prefabricated timber construction, focusing on workflow stages, software ecosystems, interoperability issues, and manufacturer-ready data requirements. Following PRISMA 2020 guidelines, 588 records from ScienceDirect and Web of Science were screened, resulting in 60 peer-reviewed studies. These were supplemented by 32 practice-based technical sources, including industry reports, software manuals, user guides, CNC/machinery manuals, and interface documents. The review maps current workflows for timber frames, trusses, and mass timber components, identifying recurring challenges such as fragmented responsibilities, insufficient data detail, incompatible software, repeated remodelling, and weak design-production continuity. Based on these findings, the paper proposes a conceptual digital integration framework emphasising early collaboration, shared parametric logic, and clearer manufacturer-ready data to support more reliable, resource-efficient, and sustainable design-to-manufacturing workflows in Australian prefabricated timber construction. Full article

Background: Digital workflows based on computer-aided design and computer-aided manufacturing (CAD/CAM) enable the modification of the vertical dimension of occlusion (VDO) during occlusal splint design; however, the clinical reproducibility of these digital adjustments compared with conventional methods remains unclear. Objective: This in vitro study aimed to evaluate the accuracy and reproducibility of vertical dimension increase achieved with three different dental CAD software systems. Methods: A standardized STL dataset was used to design occlusal splints with three CAD software systems: ExoCAD DentalCAD (Exocad GmbH, Darmstadt, Germany), InLab SW 23 (Dentsply Sirona, Bensheim, Germany), and Medit Link (Medit Corp., Seoul, South Korea). A conventional articulator-derived condition served as the comparator. Splints were manufactured using Night Guard Firm 2 Midnight resin (SprintRay Inc., Los Angeles, CA, USA), and the vertical dimension was measured with a digital caliper (Mitutoyo Corp., Kanagawa, Japan). Representative STL superimposition was performed using OraCheck 5.0 (Dentsply Sirona, Bensheim, Germany), and biomechanical behavior was assessed using ANSYS Mechanical 2025 R2 (ANSYS Inc., Canonsburg, PA, USA). Data were analyzed using one-way ANOVA followed by Tukey’s HSD post hoc tests, with the significance level set at α = 0.05. Results: The CAD systems showed variable accuracy in reproducing the reference vertical dimension; the Medit Link group yielded values closest to the reference (22.80 mm vs. 22.68 mm), the InLab group demonstrated marked overestimation (26.70 mm), and the ExoCAD group presented intermediate values (24.36 mm). One-way ANOVA confirmed statistically significant differences between the four groups for both sides (p < 0.001) with very large effect sizes (η² > 0.98). Three-dimensional superimposition revealed that the InLab splint presented the smallest mean surface deviation from the control (0.36 mm) and the highest proportion of points within 0.1 mm (59%), whereas Medit Link and ExoCAD showed larger mean global distances (0.83 mm and 0.70 mm, respectively). FEA revealed differences in biomechanical behavior, with the highest representative von Mises stress in the Medit Link geometry and the highest representative total deformation in the ExoCAD geometry. Conclusions: Digital modification of VDO is feasible, but its accuracy and reproducibility depend on the CAD system used. Careful verification of CAD design parameters against a conventional clinical reference is advisable before manufacturing occlusal splints involving vertical dimension modification, while representative 3D superimposition may provide complementary descriptive information. Full article

Background: Rapid palatal expansion (RPE) is the gold standard for maxillary deficiency in growing patients. Conventional soldered expanders often present challenges in adaptation, chairside procedures and bond stability. This study compares traditional RPEs with customized CAD (Computer Aided Design)/CAM (Computer Aided Manufacturing) expanders regarding clinical efficiency and patient experience. Methods: Thirty growing patients (mean age: 9.2 ± 1.1 years) were allocated to two groups: traditional RPEs (n = 15) and customized CAD/CAM RPEs (n = 15). Outcomes included bond failures, chairside time (from initial try into cementation) and short-term patient-reported discomfort via a 10-point Visual Analogue Scale (VAS) 24 h after appliance placement. Significance was set at p < 0.05. Results: The CAD/CAM group showed significantly fewer bond failures (0.2 ± 0.4 vs. 1.1 ± 0.8; p < 0.05) and shorter chairside time (12.4 ± 2.1 min vs. 24.6 ± 3.8 min; p < 0.001). Patient discomfort was also significantly lower in the CAD/CAM group (VAS: 4.1 ± 1.0 vs. 6.3 ± 1.2; p < 0.05). Conclusions: Within the limitations of this pilot exploratory non-randomized study, customized CAD/CAM RPEs were associated with fewer bond failures, shorter chairside application time, and lower short-term discomfort at 24 h compared with traditional appliances. These preliminary findings should be interpreted with caution and confirmed by larger randomized controlled studies. Full article

The surgical management of extremity bone defects, particularly post-traumatic nonunion wounds, remains a challenge. Vascularized bone flaps (VBFs), widely used for mandibular reconstruction in head and neck oncologic surgery, are less established in extremity reconstruction and are typically performed freehand, which has several limitations. In the past decade, virtual surgical planning (VSP) and computer-aided design and modeling (CAD-CAM) technology have enabled patient-specific 3D-printed models to guide reconstruction. While this technology has been used extensively in head and neck reconstructive surgery, its application to extremity reconstruction is less well-documented. This case series evaluates the feasibility, safety, and surgical utility of VSP and in-house CAD-CAM manufacture of 3D-printed models and cutting guides for post-traumatic non-healing extremity reconstructions using VBFs. Eight patients at a single tertiary academic center underwent VBF reconstruction guided by patient-specific models and cutting guides, with cases grouped into categories (humerus, femur, and tibia). The multi-disciplinary workflow supported preoperative visualization, osteotomy planning, and intraoperative execution. All vascularized flaps survived, and radiographic union was documented in patients with adequate follow-up. These findings suggest that integrating VSP and CAD-CAM into trauma-associated VBF extremity reconstruction is feasible and safe and may improve reconstructive accuracy and enhance multi-disciplinary team workflow, potentially contributing to improved clinical outcomes. Full article

Background/Objectives: Hysteroscopy is the gold standard for visualization and treatment of intrauterine pathology. Because hysteroscopic interpretation remains operator-dependent, artificial intelligence (AI) has been evaluated as a tool to improve consistency, lesion recognition, and decision support. We aimed to systematically review AI, machine learning (ML), deep learning (DL), or computer-aided diagnosis (CAD) applications in hysteroscopy. Methods: A systematic search of PubMed/MEDLINE and EBSCOhost was performed from database inception to 8 March 2026, supplemented by targeted searches. Risk of bias was assessed using QUADAS-2 (diagnostic), PROBAST (prognostic), RoB2, and structured technical quality domains. Results: Nineteen primary studies were included, covering five areas: diagnostic classification and object detection (n = 8), real-time lesion detection and localization (n = 4), segmentation and visual-field support (n = 3), operative guidance (n = 1), and prognostic or decision-support applications (n = 3). Performance was highest in narrowly defined binary tasks and in large multicenter systems (e.g., ECCADx: AUC 0.979 internal, 0.975 external) and in prognostic fertility-prediction models after hysteroscopic adhesiolysis (AUC up to 0.992). Broader multiclass classification of heterogeneous lesions showed uneven and lower performance. Most studies were single-center, retrospective, and lacked external validation. Only one randomized study linked AI support to measurable procedural outcomes. Conclusions: The available studies indicate good technical performance in selected hysteroscopic tasks, particularly binary classification, focal lesion detection, and postoperative fertility stratification. Current evidence, however, remains limited by retrospective design, operator-dependent image acquisition, inconsistent validation, and scarce outcome-based clinical testing. In the short term, the most likely role of these systems is to support image interpretation, improve visual quality control, highlight suspicious lesions, and integrate hysteroscopic findings with complementary clinical data. Full article

This study proposes and validates a structured methodology based on Design for Six Sigma (DFSS) for sustainable product design, addressing the lack of standardization in the integration of design tools and the need to simultaneously consider qualitative, quantitative, and sustainability-related variables. The methodology integrates Voice of the Customer (VOC), Quality Function Deployment (QFD), Theory of Inventive Problem Solving (TRIZ), computer-aided design and engineering (CAD/CAE), and Design of Experiments (DOE) within a ten-stage framework combining the stages from DMADV (Define, Measure, Analyze, Design, Verify) and IDOV (Identify, Design, Optimize, Validate) approaches. The proposed method was applied to the design of a structural concrete block, considering performance variables such as weight, factor of safety, displacement, energy consumption, and carbon emissions. The results show that the integration of QFD enabled prioritization of customer requirements, while DOE and regression models identified significant factors and interactions. Multi-response optimization using desirability functions achieved a balanced solution, improving structural performance and sustainability indicators. In particular, a significant reduction in carbon emissions was achieved. Validation through simulation confirmed the consistency between predicted and observed results. The findings demonstrate that the proposed methodology provides a systematic and replicable approach for product design, improving decision-making and supporting the development of more sustainable products. Full article