Accurately extracting lesion regions from histopathological images is crucial for diagnosing cervical squamous cell carcinoma, and determining the locations and shapes of such lesions is very important for evaluating tumor size and metastasis trends. The existing deep learning-based methods for extracting lesion regions in histopathological images primarily employ attention mechanisms to focus on regions of interest or integrate multiscale features to enhance the attained segmentation performance. However, their accuracy remains suboptimal when histopathological images with indistinct or blurred edge features are being processed. Therefore, we propose a dense prediction framework for histopathological images that integrates visual texture pattern enhancement and region-aware topological semantics via a feature interaction fusion strategy, enabling precise lesion segmentation. Specifically, our approach addresses the challenge brought by indistinct edges in pathological images through a multiscale texture enhancement branch, which sharpens discriminative morphological patterns. To optimize the feature fusion process, we introduce a positive definite-constrained attention mechanism that facilitates multilevel interactions between texture-enhanced and topological semantic features. Additionally, a united possibility state-space-model module is further designed to extract robust region-level topological semantics, thereby enhancing the ability of TexSem-Net to comprehend complex structural relationships. Extensive experiments demonstrate that our method outperforms the state-of-the-art segmentation networks in terms of both accuracy and delineation precision.

Homogeneous TPMS porous scaffolds can reduce stiffness mismatch and provide space for bone ingrowth, but their uniform architecture provides limited capacity for load-path regulation and region-specific functional adaptation. Here, we propose an arch-driven composite-gradient Gyroid TPMS scaffold that couples unit-cell size and isosurface offset through a continuous Lp-norm/Lamé-curve parameter field, translating biomimetic arch-like load-path-regulation principles into spatially varying pore size, wall thickness, relative density, and local stiffness. This design defines a load-path-regulation region and a bone-ingrowth-permissive region within a single manufacturable scaffold. Nine groups of Ti-6Al-4V cylindrical specimens were fabricated via selective laser melting and systematically evaluated through structural characterization, compression testing, finite element analysis, fatigue assessment, and a 4-week rabbit femoral defect model. The preferred E5 elliptical Lamé-field configuration achieved balanced overall performance, rather than single-metric superiority, with an apparent elastic modulus of 9.61 ± 0.59 GPa, a yield strength of 273.30 ± 10.97 MPa, a predicted fatigue-risk fraction of 0.728%, and micro-CT-supported upper/lower BV/TV values of 54.28%/45.53%. These results indicate that arch-driven spatial parameterization can redistribute mechanical response while preserving bone-ingrowth-permissive pore space. This work establishes an arch-driven parameter-field design strategy for coordinating load-path regulation, fatigue resistance, and bone-ingrowth-related responses in porous scaffold design.

Achieving a long-term, durable bond to zirconia remains a significant clinical challenge due to its chemically inert surface. In this study, we used a novel nanosilica-lithium infiltration (SI) strategy as an alternative method for modifying the surface of high translucent zirconia. This approach created a well-integrated, silica-rich reactive interface, offering a more efficient and conservative method that preserves the crystalline stability of high translucent zirconia. We compared surface characteristics and shear bond strength (SBS) before and after artificial aging for four treatment groups: no treatment (NT), SI, airborne-particle abrasion (APA), and SI followed by APA (SI-APA). Our findings demonstrated that this SI method produced a homogeneous, well-integrated, silica-rich layer (approximately 12 mu m thick, with 2 mu m of subsurface penetration). This layer significantly increased surface roughness (Ra (SI) = 0.86 +/- 0.01 mu m, Ra (NT) = 0.40 +/- 0.01 mu m; P < 0.05) without causing a phase transformation, whereas the APA group caused approximately 2% monoclinic transformation. Although the APA group exhibited the highest immediate SBS (20.67 +/- 3.28 MPa), the SBS value decreased significantly after aging (12.39 +/- 3.83 MPa, P < 0.05). Conversely, the SI group combined with 10-methacryloyloxydecyl dihydrogen phosphate (MDP)/silane-containing primer exhibited the highest post-aging SBS (16.83 +/- 1.53 MPa), which was similar to that before aging (16.99 +/- 1.39 MPa, P>0.05). Evidence from micro-topographical and spectroscopic analyses confirmed that this enhanced bond stability resulted from the synergistic effects of optimized surface wettability, mechanical interlocking, and chemical coupling. In conclusion, the nanosilica-lithium infiltration technique provides a feasible and less destructive solution for significantly enhancing the long-term bonding reliability of high translucent zirconia in clinical applications.

A multi-scale modelling framework integrating macroscopic finite element thermal-fluid simulation with a microscale phase-field method was developed to investigate the solidification microstructure evolution in a magnesium alloy during the laser powder bed fusion (LPBF) process. The macro-model accurately captures the spatiotemporal temperature field, characterized by ultrahigh temperature gradients (105-106 K/m) and cooling rates (106-107 K/s), which are dynamically mapped to drive grain growth within the microscale phase-field domain. The simulations successfully reproduced key solidification behaviors, including the epitaxial growth from the substrate, planar-to-dendritic transition, competitive growth among columnar grains with diverse crystallographic orientations, and columnar-to-equiaxed transition. While the anisotropy strength parameter was optimized to balance the interface stability and growth kinetics, the primary microstructural control was attributed to the spatiotemporal evolution of the temperature gradient (G) and solidification rate (R) within the molten pool. Specifically, the transition from high G/low R conditions at the bottom of the pool to low G/high R conditions toward the top governs competitive grain growth and ultimately triggers a columnar-to-equiaxed microstructural transition. The simulated dendritic morphologies and crystallographic orientation distributions showed excellent agreement with the experimental EBSD characterization, validating the accuracy of the model in predicting the microstructure evolution under LPBF non-equilibrium conditions.

Effective plaque biofilm control is essential for preventing caries and periodontal diseases. Although oral irrigation devices (water flossers) are widely used as an adjunct to toothbrushing, the specific influence of their core engineering parameters—nozzle diameter, working distance, and water pressure—on plaque removal efficacy remains poorly characterized in vivo, leaving both clinical recommendations and device design without robust evidence. This study aimed to systematically optimize these parameters using a digitally guided orthogonal experimental design. A three-factor, three-level orthogonal design (L9 array) was employed, testing nozzle diameters of 0.4, 0.5, 0.6 mm, working distances of 1.0, 1.5, 2.0 mm, and water pressures of 70, 80, 90 psi. For each of the nine parameter sets, personalized titanium alloy guides were digitally designed using intraoral scan data and fabricated via 3D printing to ensure precise application on six test teeth per participant (n = 12). The guide featured a retention device and a water outlet assembly with calibrated nozzles. Plaque was disclosed before and after a standardized 30-second irrigation. Plaque removal rates within the defined Target Zone (T-Zone) were calculated using a 3D quantitative analysis method based on intraoral scans. Intuitive analysis and analysis of variance (ANOVA) of the orthogonal data revealed the influence rank: water pressure > working distance > nozzle diameter. The optimal parameter combination was determined to be a 0.5 mm nozzle diameter, 1.5 mm working distance, and 90 psi water pressure. Validation with this combination achieved a plaque removal rate of 90.21

Objectives To evaluate the influence of printing orientation on the manufacturing accuracy, mechanical behavior, tooth-base transition, surface characteristics, and early Candida albicans adhesion of multi-material inkjet-printed (IJP) complete dentures. Methods Multi-material IJP complete dentures and specimens were fabricated at 0°, 45°, and 90° printing orientations. Baseline tissue-surface manufacturing accuracy and short-term storage-related dimensional changes were evaluated using 3D deviation analysis. Mechanical properties, interfacial shear performance, fracture morphology, and surface roughness were assessed at baseline and after up to 28 days of artificial saliva storage. Baseline wettability and surface free energy, together with early Candida albicans adhesion and biofilm formation, were also assessed. Results The 0° orientation showed lower tissue-surface RMS deviation and surface roughness, greater wettability, higher initial flexural and tensile strengths, and lower early Candida albicans adhesion and biofilm biomass. Tensile failure occurred within the bulk material rather than at the tooth-base transition, while interfacial shear strength varied with printing orientation and storage duration. After 28 days of artificial saliva storage, the 90° orientation showed the highest remaining flexural strength, whereas the 0° orientation showed the greatest reduction. Conclusions Printing orientation is an outcome-dependent parameter for multi-material IJP dentures. The 0° orientation favored manufacturing accuracy, initial mechanical performance, surface smoothness, and lower early Candida albicans adhesion, whereas the 90° orientation showed higher flexural strength retention after 28 days of artificial saliva storage. Orientation selection should therefore be tailored to the prioritized laboratory performance outcome. Clinical Significance Orientation control is an important consideration in IJP complete-denture fabrication because it affects tissue-surface reproduction, initial mechanical strength, short-term storage behavior, surface quality, and early fungal adhesion. These findings provide practical guidance for optimizing the printing process and establish a basis for future clinical validation.

This work reports a volumetric stereolithography strategy, termed Dynamic Projection Lithography (DPL), for the rapid fabrication of thin-walled, freeform ceramic shell structures. By spatiotemporally programming a photon flux gradient and exploiting the synergistic photopolymerization of high-solid-loading ceramic slurries, DPL enables monolithic, support-free curing of thin-walled green bodies within an ultra-short single exposure cycle of 10 +/- 0.5 s. In contrast to conventional layer-by-layer stereolithography, DPL integrates continuous three-dimensional energy-field modulation with curing kinetics, thereby eliminating interlayer interfaces and the associated defect sensitivity. Using complex-curvature zirconia dental veneers as a model, DPL achieves a volumetric fabrication rate of 129.57 mm(3)/h, representing an improvement of approximately two orders of magnitude over conventional layer-wise processes (similar to 2.58 mm(3)/h) and shortening the total manufacturing cycle from several hours to about 3.5 min. After sintering, the ceramic shells exhibit uniform, isotropic microstructures without discernible interlayer defects and show markedly enhanced mechanical performance. The combination of dynamic pulsed exposure and inverse geometric mapping ensures accurate reproduction of curved surfaces. These results demonstrate that DPL offers a highly efficient route for volumetric ceramic printing of ultra-thin freeform structures, with strong potential for biomedical and other high-value customized applications.

Interpenetrating lattice structures offer superior tailorability in physical and mechanical properties compared to single-phase structures. To achieve high strength and moderate elastic modulus, herein, gyroid-based interpenetrating lattice scaffolds for dental implants with different interpenetrating parameter (omega) were designed. The finite element simulation results showed that the interpenetrating lattice scaffold (volume fraction rho* = 40%, omega = 0.3) achieved the comparable elastic modulus as the single-phase structure (rho* = 30%), while improving yield strength by 10.11%. This is due to the mutual constraint and support between the inner and outer lattices of the interpenetrating structure, resulting in superior mechanical properties compared to the single-phase lattice structure. The maximum stress and strain values of the bone around lattice scaffolds with interpenetrating parameters of 0.3-0.8 (rho* = 40%) fell within the range of 2-60 MPa and 1000-3000 mu epsilon, respectively, both of which are favorable for bone regeneration. The permeability of the interpenetrating lattice scaffolds all remained within the permeability limits of human bone. In addition, lattice scaffolds with interpenetrating parameters of 0.3-0.8 did not exhibit toxic effects on HBMSCs cultured in vitro. This work offers a feasible design method for regulating the mechanical compatibility and biocompatibility of oral implants.

Laser powder bed fusion (LPBF) enables efficient manufacturing of implant-supported fixed complete dentures (ISFCD) Ti-6Al-4V frameworks, essential for rehabilitating edentulous patients. Yet these frameworks can suffer from accuracy and complication issues due to inadequate strength and improper appearance of supports on critical surfaces (abutment interfaces and screw channels). To address these issues, this study proposed an integrated approach combining build orientation (BO) optimisation and hybrid support generation. Specifically, a GPU-accelerated multi-objective particle swarm optimisation was developed to minimise overhang areas of the overall and critical surfaces, enabling near or complete support-free fabrication of critical surfaces. Furthermore, a novel truss-cone hybrid support based on truncated cube truss was designed to balance lightweight and mechanical performance. Through analysing frameworks' distortion under different supports, the influence mechanism of supports on the distortion was clarified. Experimental results showed that the algorithm determined the optimal BO within 10 s, reducing the median supported critical surface area to 0.03% and eliminating support on critical surfaces in one-third of cases; frameworks with new supports exhibited smaller median distalmost gaps (all below the clinically acceptable 150 mu m) and a 0.49 g reduction in support mass. This work facilitates the production of more accurate LPBF-built ISFCD frameworks, promoting their clinical application.

Segmentation of the pulmonary vessel from computed tomography (CT) images plays a crucial role in the diagnosis and treatment of various lung diseases. Although deep learning-based approaches have shown remarkable progress in recent years, their performance is often hindered by the lack of high-quality annotated datasets, in which the complex anatomy and morphology of pulmonary vessels make manual annotation challenging, time-consuming, and prone to errors. To address this, we propose PV25, the first dataset that features finely paired annotations of both pulmonary vessels and airways. Moreover, we propose TPNet, a novel tubular-aware prompt-tuning framework for pulmonary vessel segmentation under few-shot training with limited annotations. Specifically, based on an advanced and frozen segmentation backbone, TPNet proposes tunable encoding and decoding networks that learn tubular structures as transfer learning priors, bridging the gap between the source and target pulmonary vessel domains. Specifically, TPNet is built in an encoder-decoder manner, including the fixed segmentation backbone, tunable encoding and decoding networks. In encoding stage, the Morphology-Driven Region Growing (MDRG) module is developed to leverage the tubular connectivity of vessels to guide the network in capturing fine-grained features of pulmonary vessels. In decoding stage, the Cross-Correlation Guidance (CCG) module is introduced to integrate multi-scale correlations between airway and vessel structures in a coarse-to-fine manner. Extensive experiments conducted on multiple datasets demonstrate that TPNet achieves state-of-the-art performance in pulmonary vessel segmentation under limited training data. Besides, TPNet shows strong performance in related tasks such as airway segmentation and artery-vein classification, highlighting its robustness and versatility.

Zinc and its alloys are promising biodegradable materials for orthopedic implants, but simultaneously enhancing strength and ductility remains challenging. In this study, laser powder bed fusion technology was employed to fabricate zinc-copper (Zn–Cu) alloy implants. Within the optimized processing window, increasing the laser energy density elevated the melt pool temperature and provided sufficient thermodynamic conditions for grain growth, whereas decreasing the energy density accelerated cooling and suppressed grain coarsening. By grouping multiple layers and alternately applying high and low energy densities between groups, a heterostructure with alternating coarse- and fine-grained layers was constructed. These heterostructured Zn–Cu alloys exhibited an ultimate tensile strength of (245.6 ± 8.7) MPa and a ductility of (12.7 ± 0.9)%, demonstrating a remarkable strength-ductility synergy among LPBF-processed Zn-based alloys. Mechanical analysis revealed that heterodeformation-induced stress, interlayer dislocations, and the inhibition of strain localization collectively contributed to the superior mechanical performance. Additionally, the heterostructured Zn–Cu alloys exhibited typical gradient degradation characteristics and outstanding osteogenic activity, highlighting their potential for load-bearing biodegradable orthopedic applications. This work establishes a process-microstructure-property paradigm for LPBF of Zn alloys and offers a generalizable strategy for designing high-performance biodegradable metal implants.

Dynamic wet interfaces, exemplified by tooth extraction sockets, demand dressings that can maintain firm adhesion despite constant salivary flushing, suction, and mastication while actively guiding tissue regeneration. Conventional hemostatic materials detach easily under these forces, destabilizing clots and impairing healing. Here, we develop a photocurable wet-adhesive metabolic hydrogel (WAM-Gel) that integrates interfacial stability with bioinstructive metabolic signaling. The hydrogel is formed from N-acryloyl glycinamide (NAGA) and acryloyl-6-aminocaproic acid N-hydroxysuccinimide ester (AANHS), which in situ photo-crosslink into a hydrogen-bond-rich, covalently anchored dual network. This architecture provides high compressive strength, considerable burst pressure, and exceptional shear adhesion, thereby ensuring stable sealing under physiologic suction, chewing, and brushing in daily oral activities. Controlled swelling further ensures conformal socket filling and reliable clot stabilization. Beyond adhesion, the hydrogel incorporates β-hydroxybutyrate (BHB) to endow the construct with metabolic immunoregulatory functionality. As a metabolic regulator, BHB orchestrates osteoimmune programming by coupling macrophage phenotype remodeling with enhanced osteogenic differentiation, thereby fostering a pro-regenerative microenvironment. This dual action suppresses inflammatory cytokines, promotes M2 polarization, augments angiogenesis, and accelerates osteogenesis. In vivo, WAM-Gel enhanced early neovascularization, collagen maturation, and bone formation in rat extraction models, and preserved ridge contour with improved trabecular microarchitecture in beagle sockets compared with standard care. Together, this work supports a bioactive sealing strategy that integrates wet stable adhesion and metabolic regulation for osteoimmune guided regeneration at dynamic oral interfaces.

OBJECTIVE:To address clinical issues such as soft tissue trauma and patient discomfort and technical challenges such as inaccuracies in digital impression matching that are associated with traditional cord methods of gingival retraction. METHODS:This study introduced a novel pneumatic gingival-retraction scanning (PGR-S) technique inspired by clinical observations of using a three-way syringe airflow to displace free gingiva non-invasively and painlessly. This innovation was achieved through two key technological advancements: (1) creating a scanning-airflow integrated system and (2) developing a polar coordinate-based point cloud stitching algorithm that utilizes dynamic normal distance discrimination. A prospective, self-controlled clinical trial (ChiCTR2500098214) including 60 participants was conducted to evaluate the effectiveness and patient experience of PGR-S compared to that of the gingival cord-retained scanning (GC-S) and the traditional gingival cord-removed silicone impression (GC-I) methods. Additionally, operation times for PGR and GC procedures were compared. RESULTS:Statistical analysis showed significant main effects of the technique type, tooth position, and buccal/lingual location on the effectiveness of gingival retraction (P < 0.05). PGR-S had better performance with a mean of 302.9 ± 124.9 µm. All subjective evaluation metrics-comfort, pain, nausea, and dryness-differed significantly among the PGR-S, GC-S, and GC-I groups (P < 0.001). The PGR-S group reported increased comfort, but also experienced greater tissue dryness. Additionally, the operating time for PGR (70.48 ± 17.90 s) was significantly shorter than that for the GC techniques (194.78 ± 42.81 s P < 0.001). CONCLUSION:Within the limitations of this study, the novel PGR-S technique demonstrated effective gingival retraction, shortened operating time, and improved patient comfort compared to traditional methods. CLINICAL SIGNIFICANCE:This study introduces a new clinical method for minimally invasive gingival retraction combined with intraoral scanning, aiming to improve patient outcomes and comfort.

Aim or purpose: To evaluate the feasibility of PµSL technology in fabricating ultra-thin (80 μm) zirconia veneers, optimizing printing parameters for enhanced precision, mechanical strength, and clinical applicability, while minimizing tooth preparation. Materials and methods: A PµSL system with oxygen-permeable films was employed to mitigate light scattering and improve curing accuracy. Zirconia slurry (80 wt%) was used, with parameters optimized (exposure intensity: 50 mW/cm², layer thickness: 20 μm). Post-processing included debinding and sintering. Comparative analyses with CNC-milled veneers (500 μm) assessed accuracy, marginal fit, and mechanical performance. Results: PµSL-produced 80 μm thick zirconia veneers achieved superior accuracy (RMS: 20.4 ± 1.3 μm vs. 31.8 ± 2.2 μm for milled) and marginal fit (27.28 ± 6.22 μm vs. 72.80 ± 46.59 μm). Compression tests showed comparable strength (31.2 ± 2.6 N vs. 34.9 ± 4.7 N for 500 μm milled lithium disilicate veneers). Sintered zirconia exhibited uniform microstructure (grain size: ∼0.55 μm) and high density. Conclusions: PµSL enables high-precision, ultra-thin zirconia veneers with clinical-grade mechanical properties, reducing tooth preparation and enhancing biocompatibility. This technology offers a minimally invasive solution for aesthetic and functional dental restoration.

Objectives Based on the principle of air-water bubbly jets and digital technology, this study aimed to develop a personalised whole-mouth plaque removal device (PRD) for fully automated intraoral plaque control and to evaluate the clinical results. Methods PRDs were designed and fabricated for 18 subjects based on their three-dimensional (3D) dental data and plaque distribution information, followed by self-controlled intraoral plaque removal trials. Four experimental groups and three control groups were set up for the intraoral plaque removal trial. The experimental groups were all cleaned with the PRD using pure water jets, air-water bubbly jets, pure water jets after rinsing with 5% sodium bicarbonate, and air-water bubbly jets after rinsing with 5% sodium bicarbonate. The control groups consisted of habitual manual brushing, manual brushing with the modified Bass method, and single-beam pulsed water jet irrigator to clean the whole mouth. Each subject completed seven test groups in turn, and 3D information of the dentition before and after cleaning were recorded using an intraoral scanner. This trial adopted plaque removal rate (PRR; %) as the evaluation index, and combined with 3D quantitative analysis for plaque measurements on different tooth surfaces as well as Adjacent Zones. Results The total PRR and PRR in Adjacent Zones for each group were as follows: Experimental group 1 (pure water jets), 45.20 ± 1.84, 37.22 ± 6.17; experimental group 2 (air-water bubbly jets), 65.49 ± 5.17, 58.66 ± 7.95; experimental group 3 (5% sodium bicarbonate + pure water jets), 45.36 ± 5.17, 39.34 ± 5.76; experimental group 4 (5% sodium bicarbonate + air-water bubbly jets), 71.29 ± 5.02, 67.35 ± 5.39; control group 1 (habitual manual brushing), 59.02 ± 5.25, 38.02 ± 7.76; control group 2 (manual brushing with modified Bass method), 78.17 ± 5.31, 70.53 ± 8.62; control group 3 (pulsed water jet irrigator to clean the whole mouth), 32.32 ± 6.32, 21.39 ± 5.49.Statistical analysis showed that air-water bubbly jets were significantly better than pure water jets in removing plaque (P < 0.001). Adding rinsing with 5% sodium bicarbonate solution in advance improved the effect of air-water bubbly jets in removing plaque (P < 0.05), but had no significant effect on the pure water jets (P > 0.05). The plaque removal effect of air-water bubbly jets was overall better than that of habitual brushing (P < 0.01), and its advantage was more obvious in the Adjacent Zone (defined as the distance of 1 mm from the adjacent contact area to the mesial and distal) (P < 0.001), but there was still a difference when compared with the modified Bass method of brushing (P < 0.01). Conclusions This study constructed an automated plaque control method based on the principle of air-water bubbly jets, which was overall superior to habitual brushing, with its advantages more obvious in the Adjacent Zone. Clinical significance This study established the design process of a personalised whole-mouth PRD, and proposed a plaque control method that is different from conventional tooth-brushing, and verified its clinical effect.

Bone organoids offer potential for bone regeneration and in vitro organ models. Current limitations in bone organoid culture systems include low efficiency in construction and functionality, as well as increased apoptosis in prolonged cultures of larger sizes. The ketone body 3‐hydroxybutyrate (3HB), synthesized in the liver, addresses these challenges effectively. Our findings suggest that 3HB increases intracellular calcium ion (Ca 2+ ) levels in human bone marrow‐derived mesenchymal stem cells (hBMSCs) by activating the hydroxycarboxylic acid receptor 2 (HCAR2). This activation initiates the cAMP/PKA/CREB pathway, which elevates the expression of anti‐apoptotic genes such as myeloid cell leukemia 1 (MCL1) and B cell lymphoma 2‐related protein A1 (BCL2A1), thereby reducing apoptosis. Furthermore, this pathway boosts the expression of osteogenic proteins, including Runt‐related transcription factor 2 (RUNX2) and bone morphogenetic protein 2 (BMP2), facilitating osteogenesis in bone organoids. Consequently, 3HB may enhance the construction of bone organoids that are more mature, larger, and have longer viability.

Aim or purpose: To evaluate the reliability of a new method for quantitative measurement of interproximal contact tightness (ICT) under functional loading and to analyze the ICT change under different bite forces. Materials and methods: Twenty volunteers were recruited to participate in bite force control training and intraoral 3D scanning (2022SLL022). Forty sets of scanning data (the posterior teeth data, buccal light, and heavy bite data) were collected and imported into Geomagic to establish the local coordinate system (X: MD, Y: BL, Z: OG), segment the first and second molars (target teeth), create interproximal contact area feature lines, perform virtual bite registration, convert lines into feature points, and analyze their movement (including Dm, DX, DY, and DZ) under functional loading. For reliability evaluation, intraclass correlation coefficients (ICC) of ICT change were compared among the three operators. To assess differences between groups, paired t-tests were employed. Results: Whether the bite was light or heavy, the ICC was in the sequence DY>Dm>DZ>DX, and the change of the maxillary DZ was significantly greater than the mandibular (PZ=0.001, PZ=0.044). The ICT changes were substantially larger under heavy bite compared to light bite for target teeth both maxillary (Pm<0.001) and mandibular (Pm=0.006). Conclusions: The digital quantitative analysis method of the ICT change under functional loading showed good clinical reliability. Notably, under varying bite forces, there were significant differences in the ICT change. The digital method can be used to enhance fixed restoration quality and prevent food impaction.

Statement of problem. Studies that have used digital methods to quantitatively evaluate physiological tooth displacement under occlusal force are sparse. Purpose. The purpose of this clinical study was to measure physiological posterior tooth displacement under occlusal force by intraoral scanning and reverse engineering technology by using implants as the reference. Material and methods. A total of 14 participants received 15 implant-supported single mandibular first molar crowns. The surface data of maxillary and mandibular posterior teeth (U1 and L1) and the buccal occlusal data in the maximum intercuspal position (MIP) with habitual occlusal force were obtained by using an intraoral scanner (TRIOS 3, v20.1.2). The U1 and L1 data were segmented into single teeth, which were then aligned to the buccal occlusal data by using the "best-fit alignment" command to build the data under occlusal force (U2 and L2). U1 and L1 data were compared with U2 and L2 data to calculate the centroid and functional cusp vertex displacements and the long axis deflections of the second premolars and second molars, taking the first molar as the reference. The medians, and first quartile (Q1), third quartile (Q3) of the above data were reported, and the Shapiro-Wilk and Wilcoxon tests were used to analyze the differences (alpha=.05). Results. Under occlusal force, the median (Q1, Q3) centroid displacements of posterior teeth ranged from 61 (52, 101) mu m to 146 (80, 186) mu m; the functional cusp vertex displacements ranged from 82 (62, 117) mu m to 146 (98, 189) mu m, and the long axis deflections ranged from 0.45 (0.25, 0.87) degrees to 1.03 (0.52, 1.41) degrees. Mandibular second premolars displaced lingually, mesially, and apically; mandibular second molars displaced distally and apically; and maxillary second premolars and second molars displaced lingually and apically. Conclusions. A digital method taking implant-supported single crowns as the reference was used to demonstrate physiological posterior-tooth displacement under habitual occlusal force.

Objective To establish a design and fabrication method for a rigid constraint guiding template for preparing rest seats for removable partial dentures (RPDs) and to verify the feasibility and accuracy of template-guided preparation in vitro. Methods Twenty identical Type IV gypsum casts of Kennedy Class II mandibular partially edentulous arch (missing teeth #36, #37, #45 and #46) were replicated and evenly divided into two groups: the template-guided group and the freehand group. Virtual preparation of rest seats on three abutment teeth were performed, and two rigid constraint preparation templates were designed and three dimensional (3D) printed using titanium alloy. A trained prosthodontist used the template-assisted method and the freehand preparation method to prepare rest seats for both groups respectively. The root mean square errors (RMSE) of 3D trueness and 3D precision of prepared rest seats in both groups were analyzed using the 3D compare method. Finally, a single-blind subjective scoring and quantitative analysis of the rest seat preparation were conducted by another trained prosthodontist. Results The positioning accuracy of the rigid constraint templates for rest seat preparation was (249 (79.4) μm). The 3D accuracy (138.09 ± 30.33 μm) and 3D precision (100.20 (79.60) μm) of the rest seat preparation using the rigid constraint template were superior to the 3D accuracy (253.44 ± 38.84 μm) and 3D precision (217.70 (121.25) μm) of the freehand preparation (P < 0.001). The scoring results for the quality of the rest seat preparation indicated that the morphology and position of the rest seats prepared using the template were significantly better than those prepared by the freehand method (P < 0.05). Conclusions The rigid constraint template accurately guided the diamond bur to prepare rest seats that meet clinical requirements on multiple abutment teeth. Compared to freehand preparation by a trained prosthodontist, the template-guided preparation resulted in better shape and position of the rest seats, significantly reducing the dependency on the experience and skills of the clinicians. Clinical significance The rigid constraint metal template offers a new digital auxiliary method for achieving stable and high-quality rest seat preparation for RPDs.

In this study, CaO-doped 3Y-ZrO2 powders were synthesized via a hydrothermal process by adding various concentrations of CaCl2 to the precursor solution. The microstructure, hardness, and wear behavior of the sintered samples were systematically investigated. X-ray diffraction confirmed that the as-prepared zirconia powders were single-phase cubic. After sintering, the undoped 3Y-ZrO2 ceramic consisted predominantly of the tetragonal ZrO2 phase, whereas all CaO-doped samples exhibited a cubic phase without any secondary phase. Although more than 30 mol% CaCl2 was added to the precursor solutions, the CaO-doped 3Y-ZrO2 ceramics attained similar final CaO contents (approximately 9.7 mol%- 11.3 mol%). Microstructure analysis showed that the grain size of the cubic phase in CaO-doped 3Y-ZrO2 ceramics was much larger than that of the tetragonal grains in the undoped ceramic. Notably, the zirconia ceramic derived from a precursor with 60 mol% CaCl2 addition achieved the best mechanical strength and a significantly reduced wear resistance, suggesting it may be suitable for future applications (e.g., as a dental ceramic).