Dental materials journal最新文献

To know about whether a bone substitute material octacalcium phosphate (OCP) is associated with bone formation by acting on surrounding tissue-derived cells, such as muscle cells, the effect of OCP was investigated on muscle-derived myoblast C2C12 cells in vitro. C2C12 cells were cultured with or without OCP granules. The diameter of the myotube formed from C2C12 cells with OCP was larger than that without OCP. mRNA expressions of myoblast differentiation markers (MyHC, MCK) and myokine (FGF-2) were increased by OCP, while Fndc5 and osteoglycin (myokine) were decreased. The alkaline phosphatase activity of mesenchymal stem cells was increased by adding the extract of media cultured with C2C12 cells and OCP up to 14 days. The chemical and spectroscopic analyses indicated that OCP hydrolysis progressed towards Ca-deficient hydroxyapatite in the media. The results suggest that OCP promotes myoblast differentiation and assists osteoblast differentiation through the myokines secretion under the environment induced by OCP hydrolysis.

Elucidate the dicalcium phosphate dihydrate (DCPD)-coated-beta-tricalcium phosphate (β-TCP) porous granules osteoinductivity performance in adipose-derived mesenchymal stem cells (ADMSCs). β-TCP porous was made by adding the sodium chloride (NaCl) powders with the dry powder of DCPD and CaCO₃ in the concentrations 40:60 (by wt%). Then, DCPD layer will be formed on porous β-TCP granules by immersing the granules in an acidic calcium phosphate solution. ADMSCs cultured was used to examine the biocompability of 300-600 µm and 600-1,000 µm DCPD-coated-porous β-TCP by means of microculture tetrazolium technique (MTT assay) and scratch assay. Bone morphogenic protein-2 (BMP-2), Osterix, Runt-related transcription factor-2 (Runx2), Alkaline phosphatase (ALP), Osteopontin, Osteonectin expression were investigated. The DCPD-coated porous β-TCP granules were culture together with ADMSCs is biocompatible. BMP-2, Runx2, Osterix, ALP, Osteopontin, Osteonectin expression in ADMSCs after culture together with DCPD-coated-β-TCP significantly enhanced. DCPD-coated-porous-β-TCP granules have good biocompatibility and high osteoconductivity in ADMSCs.

Low-wear resistance is a considerable problem with titanium. Despite the excellent wear resistance of Ti-Fe alloys, they exhibit brittleness, complicating their bulk usage. We developed a surface modification method for Ti involving the solid-phase diffusion of iron onto its surface. We coated iron onto the titanium surface and applied heat to successfully form a Ti-Fe alloy layer only on the outermost surface of titanium. The alloy layer exhibited a gradient structure characterized by a continuous decrease in iron concentration from the surface inward, without forming a distinct interface with the base material. Under various heat treatment conditions, the outermost alloy phase of the diffusion layer, in the β phase, resulted in surfaces with exceptional wear resistance. The improved wear resistance can be attributed to the potential surface structure of the Ti-Fe alloy, which combines hardness and ductility. This titanium-integrated structure, resulting from the gradient composition, reduces the likelihood of delamination.

This study was designed to investigate the effect of biodegradable octacalcium phosphate (OCP) bone substitute on osteoclast formation under the higher inorganic phosphorus concentration in vitro. We developed the gelatin particles releasing inorganic phosphate (Pi) ions as a model to change the local Pi ion concentration around OCP in the OCP/gelatin composite materials. Spectroscopic and chemical analyses indicated that Pi ion released around 2 mmol/L from gelatin particles promoted OCP hydrolysis, although excessive Pi ion release up to around 3 mmol/L suppressed the hydrolysis. The formation of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells was increased by the OCP hydrolysis promotion via modulately higher Pi release Pi ion release. However, OCP hydrolysis suppression by excessive Pi ion release decreased the formation of TRAP-positive cells. The present study suggests that the chemical environment induced by OCP hydrolysis under a suitable Pi ion concentration could be associated with promoting osteoclast formation.

Invisible orthodontics benefits significantly from aligner technology, yet optimizing material properties and thickness for diverse patient needs is a challenge. The aim of this study was to investigate the interaction between key material properties and thickness-and their collective influence on orthodontic treatment outcomes. A three-dimensional model of the tooth, periodontal ligament, and bone complex was constructed, with attachments centered on each tooth crown. Nine aligners, varying in thickness from 0.20 to 1.00 mm with material properties (Young's modulus (E) from 0.01 to 3.50 GPa and Poisson's ratio (ν) at 0.30), were analyzed. The study measured force and moment changes due to a 0.15 mm mesial-distal movement of the lateral incisor, validated by other teeth. Results show aligner thickness and E significantly affect force and moment, with increases promoting translational rather than tipping movements. These findings underscore precise aligner design's role in enhancing orthodontic outcomes.

Commercial toothpaste contains 1,500 ppm NaF to prevent caries; however, the effect of NaF on tooth restorative materials is not fully understood. This study investigated the impact of a 1,500 ppm NaF solution at different pH levels on the mechanical and physicochemical properties of CAD-CAM materials. Aqueous 1,500 ppm NaF solutions were prepared at pH levels 3, 5, and 7. Four CAD-CAM blocks -lithium disilicate glass, feldspathic porcelain, polymer-infiltrated ceramic network, and resin composite- were immersed in the solutions at 37°C for 10 days. Samples were evaluated for surface roughness, flexural modulus, strength, Vickers hardness, and water sorption/solubility. Results indicated that NaF solutions dissolved silica components, increasing surface roughness and water solubility and reducing hardness, especially at lower pH levels. Flexural properties remained mostly unchanged. These findings suggest that acidic NaF solutions more strongly degrade the surface properties of CAD-CAM materials.

Mineral trioxide aggregate (MTA) cement has excellent properties, such as biocompatibility and mineral induction ability for various dental procedures. To provide these favorable properties, MTA-based sealers, such as MTA Fillapex (MF), Bio-C Sealer (BC), NeoSEALER Flo (NSF), and NeoMTA 2 (NM2), have been developed and introduced into the market. Additionally, an endodontic sealer containing bioactive glass with mineral induction ability was introduced as the Canal Sealer BG (CS-BG). In this study, we evaluated the mineral induction and sealing ability of five bioceramic-based sealers. The results indicated that NSF, NM2, BC, and CS-BG had superior mineral induction capacities compared with MF. Although NSF, NM2, BC, and CS-BG exhibited comparable sealing performances, NSF had a statistically superior sealing capability compared to MF. According to these findings, bioceramic sealers other than MF containing resin components have excellent mineral induction capacity, making them effective for root canal sealing in clinical applications.

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.