The aim of this study was to externally validate object detection models for comprehensive tooth detection on pediatric panoramic radiographs, quantify the impact of domain shift across institutions and imaging protocols, and compare YOLOv8 and YOLOv10. Two datasets were used: an internal set of 200 images of early mixed dentition without bite blocks, and an external, open-source set of 192 images acquired with bite blocks. Performance was assessed using mean average precision (mAP), per‑class AP, precision‑recall curves, and confusion matrix. Overall performance was high but domain dependent. mAP was 0.958/0.941 (YOLOv8/v10) in Experiment 1; 0.910/0.906 in Experiment 2; and 0.906/0.901 in Experiment 3. Error analysis revealed domain‑specific failure modes: bite blocks were occasionally mistaken for the primary central incisor. Deep learning enables accurate and comprehensive detection of teeth on pediatric panoramic radiographs. However, domain shift alters error patterns and impairs the detection of rare yet clinically important classes.

Bone substitutes from various sources have been used to facilitate bone regeneration. In this study, we performed a comparative analysis of the effects of marine mollusk shells and their bioactivities on osteoblasts and osteoclasts. The results showed that the surfaces of A. granulosa and C. belcheri shells had higher surface roughness than that of P. viridis. Different surface morphologies but similar elements were found on the surfaces of all shell groups, and additional elements, particularly silicon, were found on the surface of A. granulosa. After growing osteoblasts on the shells for 4–7 days, C. belcheri, P. viridis, and A. granulosa shells had significantly more cells than P. undulata shells. Similar osteoblast differentiation was observed in all shell groups after 7–14 days. All shell groups, particularly C. belcheri and P. viridis, favored osteoclast formation. This study suggests the potential use of mollusk shells to develop alternative biocompatible bone-substitute materials.

This study aimed to develop a low-toxicity etchant for bonding pretreatment of silica-based CAD-CAM materials. An experimental etchant was prepared by combining ammonium hydrogen fluoride (AHF) with ammonium hydrogen sulfate (AHS) and subsequently optimized. The optimized AHF/AHS etchant was evaluated on lithium disilicate glass, feldspathic porcelain, polymer-infiltrated ceramic network, and resin composite, and compared with hydrofluoric acid (HF), a commercial etchant (Monobond Etch & Prime; MEP), and alumina sandblasting. For lithium disilicate glass, shear bond strength (SBS) obtained with AHF/AHS treatment was higher than that with MEP but lower than that with HF. For feldspathic porcelain and polymer-infiltrated ceramic network, SBS obtained with AHF/AHS was comparable to those obtained with HF. For resin composite, SBS obtained with AHF/AHS was higher than that with untreated control while lower than that with sandblasting. Cytotoxicity evaluated using human gingival fibroblasts showed IC₅₀ values comparable to those of phosphoric acid and sodium fluoride.

Titanium crowns were fabricated using two types of powder bed fusion processes, electron beam melting (EBM) and selective laser melting (SLM), to investigate how building orientation affects dimensional accuracy. A cylindrical model, representing a full crown, was manufactured using both methods at three angles on the build platform (0°, 45°, and 90°). The outer and inner margin diameters, as well as the depth, were measured, and the change rates from the designed values were calculated. Additionally, the circularity of the outer and inner margins and the concentricity between them were evaluated. Results indicated larger change rates in the EBM specimens compared to the SLM specimens. The 90° specimens exhibited the highest circularity in both EBM and SLM. These findings confirmed that EBM is inferior to SLM in terms of dimensional accuracy for crown fabrication and demonstrated that the arrangement of the 3D data significantly affects accuracy.

This study evaluated the effect of an MDP-containing cleaner on the bond strength of a self-adhesive resin composite (SAR) to saliva-contaminated bovine root dentin. Dentin surfaces were ground with #600 SiC and contaminated with artificial saliva for 20 s. Specimens were divided into four groups: water rinse (WA), 10% citric acid-3% ferric chloride solution (10-3), MDP-containing cleaner (KC), and non-contaminated (NC). SAR was applied according to the manufacturer’s instructions. After 24 h of water storage at 37°C, μTBS was measured (n=10). KC showed no significant difference in μTBS compared with the NC (p>0.05), while no measurable bond strength was obtained for the WA and 10-3. Mixed failures comprising cohesive failure within dentin, cohesive failure within resin, and adhesive failure at the dentin–resin interface were more frequent in the NC. KC effectively removed contaminants and restored bonding performance. This method offers a promising restorative protocol for challenging clinical settings.

It is essential to minimize dental pulp exposure to external stimuli to maintain pulp vitality. Therefore, pulp-protective materials require sealing ability, antibacterial activity, and biocompatibility. Conventional glass ionomer cement (GIC) possesses some of these properties, while calcium 4-methacryloxyethyl trimellitate (CMET) can induce calcification, suggesting potential utility in pulp protection. This study compared conventional GIC, CMET-modified GIC (C-GIC), and Ca-free 4-methacryloxyethyl trimellitate (4-MET)-modified GIC (4M-GIC). 4M-GIC showed decreased compressive strength and shear bond strength, whereas C-GIC exhibited only a reduction in compressive strength without affecting bond strength. Both C-GIC and 4M-GIC released increased levels of Sr²⁺, Ca²⁺, Si²⁺, F⁻, and Al³⁺. Notably, C-GIC demonstrated antibacterial activity comparable to that of GIC and 4M-GIC, along with lower cytotoxicity, greater cell proliferation, and increased alkaline phosphatase (ALP) activity and calcium deposition. These findings indicate that CMET incorporation enhances adhesion, ion release, antibacterial activity, and mineralization, indicating that C-GIC as a multifunctional pulp-protective material.

We evaluated the effects of adding the fluorinated monomer 2,2,2-trifluoroethyl methacrylate (TFEMA) and varying amounts of the plasticizer acetyl tributyl citrate (ATBC) on the gelation of light-cured soft denture liners. The liquids contained 2-ethylhexyl methacrylate (2-EHMA) and ATBC, with traces of a photo initiator and reducing agent, and the powder was poly(ethyl methacrylate/butyl methacrylate). Four 2-EHMA:TFEMA ratios and two monomer:plasticizer ratios were tested with a powder/liquid ratio of 1.0. Gelation time was measured using a controlled stress rheometer. Gelation time decreased exponentially with increasing TFEMA content in the monomer. Conversely, higher proportions of ATBC in the liquid prolonged gelation. The influence of monomer composition (2-EHMA:TFEMA) on gelation was greater than that of ATBC content. These results indicate that gelation kinetics can be widely controlled by the addition of TFEMA, and a formulation of 50 wt% monomer (2-EHMA:TFEMA=60:40)/50 wt% plasticizer (ATBC) represents a suitable liquid composition for soft denture liners.

The enhanced bonding performance of dental cements is a clinical challenge, resulting in tooth damage because of excessive adhesion. Consequently, novel smart dental cements capable of on-demand bond strength reduction upon the application of an electrical current (CA) have been developed. Notably, a significant reduction in the shear bond strength (σ_s) of resin-modified glass-ionomer cements (RMGICs) has been reported after the application of a 19 V CA for 30 s. However, this high voltage can damage the soft tissue and dental pulp. Therefore, we investigated whether comparable debonding performance could be achieved at lower voltages. The results showed a significant reduction in σ_s. Importantly, debonding effects equivalent to those obtained with the 19 V condition were achieved at substantially lower voltages of 10–12 V. These findings indicate that reducing the applied voltage can maintain debonding performance while minimizing excessive electrical stimulation during current application.

Tissue engineering scaffolds with precisely engineered surface topographies have emerged as critical tools for the spatiotemporal regulation of cellular behavior in bone regeneration. Here, we propose a biomimetic approach for replicating the curvilinear architecture of native osteons through soft lithography and melt casting to fabricate polycaprolactone (PCL) membranes featuring wave-patterned microgrooves with three geometrically graded dimensions and a uniform depth of 10 μm: L1 (inner radius: 10 μm, outer radius: 20 μm), L2 (30 μm/60 μm), and L3 (60 μm/120 μm). The experimental results revealed that the wave microgrooves enhanced cell proliferation to varying degrees and that the cells utilized contact guidance to grow along the wave microgroove topographies. MC3T3-E1 cells showed more pronounced nuclear deformation in the L2 and L3 groups, while RAW264.7 cells displayed greater deformation in the L1 and L2 groups. Notably, the L3 configuration (60 μm/120 μm) demonstrated optimal dual functionality, synergistically promoting osteogenesis while inhibiting osteoclastogenesis. This unique combination of properties highlights the potential of this PCL-based guided bone regeneration (GBR) membrane for enhanced bone repair applications.

Early caries is initiated by bacterial colonization and biofilm maturation, which drive localized demineralization of enamel. This study developed a borneol-grafted poly(amidoamine) dendrimer to inhibit bacterial adhesion, suppress biofilm formation, and enhance enamel remineralization. Borneol-grafted poly(amidoamine) dendrimer was synthesized via imine linkage and evaluated for antibacterial activity against Streptococcus mutans and Streptococcus sanguinis assessed by adhesion inhibition, and biofilm biomass/viability assays. Mechanisms were explored by zeta potential analysis and scanning electron microscopy. Remineralization was assessed by microhardness, lesion depth, mineral density, X-ray diffraction, and surface morphology; in vivo efficacy was tested on human enamel samples in an intra-oral model. Borneol-grafted poly(amidoamine) dendrimer reduced bacterial adhesion and viability, neutralized surface charge, and affected membrane integrity. In vitro, borneol-grafted poly(amidoamine) dendrimer improved hardness, reduced lesion depth, and increased mineral density; in vivo, it promoted mineralized layers without systemic toxicity. These findings indicate it as a single-scaffold preventive–restorative agent for early-stage caries.

We aimed to compare the bone regeneration capacity of two atelocollagen sponges with distinct porosity, pore size, and pore morphology: Atelocollagen Sponge MIGHTY^® (MIGHTY) and the three-dimensional Honeycomb Boosted^® scaffold (Honeycomb). Scanning electron microscopy revealed that Honeycomb exhibited a continuous linear pore structure with a uniform honeycomb-like architecture, higher porosity, and larger pores than MIGHTY. Each sponge was placed in a high-density polytetrafluoroethylene dome and fixed to the rat calvaria. X-ray micro-computed tomography showed that Honeycomb increased bone volume fraction approximately 2.4-fold and 2.3-fold at 4 and 8 weeks post-implantation, respectively, compared with MIGHTY. At 12 weeks post-implantation, bone volume fraction was comparable; however, trabecular number in Honeycomb remained approximately two-fold higher. Histological and immunohistochemical observations confirmed enhanced bone formation, suggesting relatively early angiogenesis and progressive mesenchymal stem cell involvement. Overall, these results indicate that the Honeycomb scaffold supports early bone regeneration.

Periodontal ligament (PDL) is essential in supporting tooth, remodeling, and regeneration of periodontal tissues; however, donor-derived PDL cells have limited regenerative applications. We previously developed a method to generate PDL-like cells from induced pluripotent stem (iPS) cells using PDL-conditioned medium. In this study, we validated whether iPS-derived PDL cells (iPS-PDL) recapitulate established functions of PDL cells. Morphologically, iPS-PDL resembled primary PDL cells and exhibited a higher proliferative capacity. They expressed PDL-related genes, such as Periostin, Asporin, and Tenascin-C, at levels exceeding those of fibroblasts. Under osteogenic induction, iPS-PDL deposited a mineralized matrix and upregulated the expression of COL1A1, ALPL, OCN, and RUNX2. Ascorbic acid enhanced ALP activity and collagen synthesis, while compressive force induced IL6, IL1β, and COX2 expression, These findings demonstrate that iPS-PDL retain PDL-like functions and are a promising cell source for periodontal regeneration, offering the potential for both therapeutic applications and in vitro modeling of periodontal biology.

This study reports the fabrication and characterization of biocomposite scaffolds combining Aceh-sourced bovine hydroxyapatite (BHA) and gelatin (GEL) for bone repair. The scaffolds were evaluated for physicochemical, mechanical, and biological properties. Fourier-transform infrared spectroscopy confirmed functional groups from both BHA and GEL. Energy-dispersive X-ray spectroscopy detected bone-related elements (Ca, P, O) and traces (Na, Mg, Al). Thermogravimetric analysis indicated thermal stability up to 600°C, and highest crystallinity (59.2%) at a 7:3 BHA:GEL ratio. Scanning electron microscopy and porosity analyses revealed an interconnected porous structure (40–295 μm pores, 72–86% porosity) supporting cell infiltration. Scaffolds exhibited favorable degradation (83–87%), swelling (675–836%), density (0.30–0.36g/cm³), compressive strength (0.22–0.44 MPa). MTT assay confirmed high osteoblast viability (78.9%), while in vivo tests demonstrated normal inflammation and accelerated bone regeneration. These findings support BHA-GEL biocomposites as cost-effective, locally sourced, biocompatible scaffolds for bone tissue engineering applications.

This study investigated the effects of build orientation and water-storage duration on the dimensional accuracy of fused deposition modeling (FDM)-fabricated polyetheretherketone (PEEK) removable partial denture (RPD) frameworks. The specimen geometry was designed using computer-aided design (CAD) software to simulate a maxillary RPD framework and printed in three build orientations (0°, 45°, 90°; n=6). After annealing, specimens were immersed in 37°C water and scanned after 24 h, 1 week, 1 month, 2 months, 4 months, and 6 months. Trueness was calculated by superimposing scanned stereolithography (STL) data onto the CAD reference, and precision was assessed within each group. Storage duration significantly influenced trueness and precision, with clinically acceptable accuracy achieved after 24 h and maintained stable for more than 2 months under simulated intraoral moisture and temperature. The 90° orientation demonstrated the most consistent reproducibility.

In this study, a commercially available tissue conditioner (TC; Soft-Liner, GC, Tokyo, Japan) was modified by incorporating quaternary ammonium salts (QAS): dimethyl-hexadecyl-methacryloxyethyl-ammonium iodide (DHMAI) and 2-dimethyl-2-dodecyl-1-methacryloxyethyl ammonium iodide (DDMAI) based on their minimum inhibitory and bactericidal concentrations (MIC and MBC). The control group consisted of TC materials without monomers. The modified TC was characterized by Fourier transform infrared spectroscopy, antimicrobial activity (microbial adherence) assessed against Streptococcus mutans (S. mutans), Staphylococcus aureus (S. aureus), and Candida albicans (C. albicans), and cytotoxicity (MTT assay) on L-929 fibroblasts. Additionally, mechanical and physical properties were assessed. Our results suggest that modified TC has effectively reduced microbial adhesion, exhibited good cytocompatibility and no significant changes were observed in the mechanical properties compared to control samples.