This study aimed to evaluate the initial bond strength to dentin with a new self-adhesive resin composite containing a hydrophilic amide monomer using a micro tensile bond strength (μTBS) test. Specimens were ground with #600 SiC. Including a Cleafil Universal Bond Quick ER (UBQ) and resin composite, a new self-adhesive resin composite (SA-100R; SAR), and a commercially self-adhesive resin composite (Constic; CON), were tested. Adhesion procedures were conducted according to each manufacturer’s instructions. Specimens were stored for 24 h in water at 37ºC, then cut into a 1.0×1.0 mm beams. μTBS tests were conducted at a cross-head speed of 1.0 mm/min. Data were statistically analyzed using one-way ANOVA and Bonferroni correction. SAR exhibited values significantly higher than CON (p<0.05), probably due to the improved dentin diffusion by the amide monomer. SAR exhibited stronger adhesion than the CON, shows a high potential for use in various clinical applications, e.g., home-visit dental care.

Surface pre-reacted glass (S-PRG) fillers, a new type of bioactive molecule, can release various ions (Al³⁺, BO₃³⁻, Na⁺, SiO₃²⁻, Sr²⁺, and F⁻) and exhibit high biocompatibility, good antibacterial properties, low plaque accumulation, and enhanced osteoblast differentiation. An alkali-treated titanium layer with a porous nanonetwork structure (TNS) promotes cell adhesion and produces a stronger osseointegration effect than that of a non-treated titanium layer. In this study, the osseointegration effect of TNS was enhanced by incorporating an S-PRG eluate solution. The efficiencies of TNS coatings with different S-PRG concentrations were determined by performing surface analysis, cell experiments, and animal experiments. The results revealed that the introduction of the S-PRG eluate solution promoted the osteogenic ability of TNS. The combination of these two materials offers a novel approach to the investigation of oral implant materials.

This study investigated the influence of bonding agents on metal-ceramic bond strengths before porcelain veneering for cobalt-chromium alloy. Three ceramic systems: Initial MC (IMC), Hera Ceram (HC), and ZEO CE LIGHT (ZCL) were tested on wrought substructures. The ZCL system was also tested on cast substructures. Three-point bending test was performed, and fractured surfaces were analyzed using electron-probe microanalysis and X-ray diffraction. The bond strengths of all specimens exceeded the requirements of ISO 9693:2019 (>25 MPa). The ZCL bonding agent significantly improved bond strengths for wrought and cast substructures whereas the IMC and HC bonding agents did not. Wrought-ZCL specimens exhibited significantly higher bond strengths than cast-ZCL specimens. In the specimens exhibiting higher bond strength, silicon and titanium, which originated from the bonding agent, were predominantly detected at the debonded metallic surfaces. Consequently, the bonding agent positively affected the bond strength but depended on the ceramic system and substructure type.

Bioceramic materials like bioactive glass (BG) are widely used in endodontics due to their bioactivity and osteoinductive properties. This study characterized fluorescence-labeled porcine immortalized dental pulp cells (DsRed-PPU7 cells) in contact with BG-based cement (BG-C) to advance the development of novel BG-C formulations. BG-C discs were prepared on titanium discs, and DsRed-PPU7 cells were cultured on them. The effects of bone morphogenetic protein-2, transforming growth factor beta-1, and their inhibitors (LDN-193189 and SB-431542) on cell proliferation and mineralization were investigated. Additionally, a new BG-C disc containing LDN-193189 (LDN-BG-C) was developed and tested. The LDN-193189 significantly promoted cell proliferation and mineralization. On LDN-BG-C discs, the formation of petal-like spherical precipitates with hydroxyapatite-like structures was observed, aligning with the cell localization sites. We propose that BG-C discs containing LDN-193189 induces the differentiation of dental pulp cells into odontoblast, and promotes the formation of dentin-like crystals.

Tongue reconstruction after cancer resection often involves the use of free skin flaps. However, this strategy has limitations. To overcome these issues, tissue engineering approaches using basic fibroblast growth factor (bFGF) have been investigated to promote tongue muscle regeneration. In this study, a chimeric protein consisting of bFGF and a collagen-binding peptide (CBP-bFGF) was evaluated for its ability to promote myoblast infiltration into collagen-based scaffolds. Results showed that CBP-bFGF promoted the migration of C2C12 myoblasts and their infiltration into collagen sponges. Based on these observations, we propose that the binding of CBP-bFGF with a collagen sponge provides one of the options for accelerating tongue muscle regeneration.

Additive-manufactured (AMed) Co-Cr and Ti alloy clasps were made with five surface treatments. Either one of a conventional freehand finishing or barrel finishing as a medium finishing process or one of a freehand, dry electrolytic, or magnetic polishings was selected as the final polishing process. After each surface treatment, the polishing efficiencies of the AMed clasps were evaluated as to surface roughness, fitness accuracy, and retentive forces. By surface treatments without using magnetic polishing, sufficient surface smoothness was observed for both alloys. Under all five treatment conditions, better fitness accuracies and sufficient retentive forces were obtained in all Co-Cr and Ti alloy clasps for clinically acceptable results. A combination of barrel finishing and dry electro-polishing can be recommended as the automatic finishing technology, replacing the freehand polishing process by dental technicians. The findings of this study will significantly reduce the workload of dental technicians.

This study evaluated the cusp tip deflection of aluminium tooth models with a mesial-occlusal-distal (MOD) cavity filled with three bulk-fill resin-based composites (RBCs), Aura Ultra Universal (Aura), Admira Fusion x-tra Universal (Admira), and Filtek One shade A2 (Filtek One), to assess the level of shrinkage stress they could produce. The models were prepared using a primer, adhesive and a single RBC increment photo-cured for 20 s at a radiance exitance 1.25 W/cm². The RBC axial shrinkage strain (ε) and stress (S) were also measured. Micro-computed tomography in combination with silver nitrate infiltration showed no interfacial debonding. The mean cusp tip deflection for Admira was found to be smaller than those for the other two RBCs. Although ε and S for Aura were higher than those for Filtek One, their mean cusp tip deflections were not significantly different. These results could be explained by the temporal behavior of their elastic modulus.

This study aimed to evaluate the usefulness of light-cured resin coating restoration materials (RCs) on anterior composite resin blocks by quantifying the color, gloss, and surface roughness before and after toothbrush abrasion test and to evaluate the shear bond strength before and after thermal cycling test. Four types of RCs were used in the experiments. The application of RCs to composite resin blocks resulted in color changes and a decrease in gloss after the toothbrush abrasion test; however, both were within clinically acceptable limits. The surface roughness was at a value that made bacterial adhesion difficult both after the application of RCs and after the toothbrush abrasion test. The shear bond strength also had clinically acceptable bond strength. Therefore, the application of RCs to composite resins in the oral cavity is considered effective in terms of maintaining esthetics, gloss, and surface properties, as well as the durability of RCs.

A tongue-controlled intraoral pointing device for operating information and communication terminals, such as computers, which allows the wearer to perform oral training while typing, was developed. Its effectiveness was evaluated in healthy participants. There were no differences in typing speed for the same input between computers with any operating system/display combination. Typing with the developed device was performed at 80% of the speed compared to using a stylus pen held in the mouth, the conventional method used by persons with upper limb disabilities. Electromyography signals increased concomitantly by 1.8-fold in the buccal and 2.0-fold in the submandibular area. There was a 2.5-fold increase in saliva secretion and a decrease in salivary α-amylase activity to 40%, indicative of stress. The computerized operation of this device is expected to contribute to the prevention of oral frailty by maintaining and strengthening oral functions and hygiene.