Dental materials journal最新文献

Sandblasted with large grits and acid-etched (SLA) surface topography has been a common method of implant surface modification to promote bone-implant integration in titanium-based dental implant manufacturing. However, the acid etching protocols used are various. The aim of this investigation was to validate the effect of different acid-etched treatments of sandblasted titanium surfaces on enhancing osteogenic potential. Five different titanium surface groups were prepared and tested including: i) smooth (Control), ii) sandblasted (SL), iii) sandblasted and acid-etched with H₂SO₄/HCl mixed solution (SLA/SOCl), iv) sandblasted and acid-etched with H₂SO₄ solution (SLA/SO), and v) sandblasted and acid-etched with HF solution (SLA/HF). The surface characterization, protein adsorption, and cell behavior were examined to determine the osteogenic potential. Compared with the control group, other surface treated groups showed rougher surface, better wettability, more protein absorption, and cell viability, especially in the SLA/SOCl surface group. The results indicated that SLA surfaces prepared with H₂SO₄/HCl mixed acid solution provided significant potential to promote osteogenesis.

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.

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.

This study focuses on enhancing the mechanical properties and biocompatibility of calcium phosphate cement (CPC), a widely used bone replacement material. CPCs are limited by low mechanical strength and susceptibility to washout in body fluids. Four approaches were employed to improve CPC performance: 1. mechanochemical modification of CPC powder by ball milling to produce modified β-tricalcium phosphate (mβ-TCP) for better strength and injectability; 2. incorporation of poloxamer, a reverse thermosensitive gel, to enhance shape stability at body temperature; 3. addition of type I collagen to promote the cell viability and alkaline phosphatase (ALP) activity of osteoblast-like cells; 4. citric acid inclusion to restore compressive strength and injectability compromised by collagen. The resulting high-performance CPC demonstrated a compressive strength of 50.1 MPa, with significant improvements in injectability, shape stability, cell viability, and ALP activity of osteoblast-like cells.

Surface pre-reacted glass (S-PRG) fillers, a new type of bioactive molecule, can release various ions (Al³⁺, BO₃^3-, Na⁺, SiO₃^2-, 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.

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.

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.

Appropriate self-cleaning denture base materials should be developed to prevent denture stomatitis and aspiration pneumonia in older patients and improve their quality of life. We aimed to develop a new denture base material by introducing titanium apatite, an antibacterial material, into a conventional denture base resin. We added titanium apatite (TiHA) during polymerization of methyl methacrylate (MMA) to PMMA. The control group was composed of 0% TiHA, and the experimental groups were composed of 3%, 6%, and 9% TiHA. Surface analysis revealed the distribution of the TiHA crystals on the PMMA surface in the experimental group. We found that the higher the TiHA concentration, the more bacterial growth was suppressed. No significant reduction in the compressive strength was observed. In conclusion, TiHA is a useful material in denture base resin since it is resistant to surface contamination and bacterial adhesion.

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.