Novel Subperiosteal Device Geometry and Investigation of Efficacy on Surrounding Bone Formation and Bone-Bonding Strength.

To develop a safer bone-bonding device that promotes early osseointegration with cortical bone perforation, novel subperiosteal device geometries were proposed and evaluated for their ability to facilitate surrounding bone formation and enhance bone-bonding strength. This study used animal experiments and mechanical testing to assess the performance of these designs. The experimental device consisted of two main components: a rounded rectangular plate and a centrally positioned cylinder.

Evaluation of Cortical Bone Microdamage and Primary Stability of Orthodontic Miniscrew Using a Human Bone Analogue.

Orthodontic miniscrews have gained popularity; however, they have some drawbacks, including screw loosening that results from bone resorption caused by excess microdamage created during screw insertion. Pilot hole preparation through the cortical bone is considered beneficial to avoid such microdamage, while an overly large pilot hole impairs primary stability. Hence, we used a human bone analogue to evaluate the microdamage and primary stability to estimate the optimal pilot hole size that would minimize the screw loosening risk.

Enhanced bone formation onto the bone surface using a hydroxyapatite/collagen bone-like nanocomposite.

The process of bone formation onto the bone surface using a hydroxyapatite/collagen bone-like nanocomposite (HAp/Col) was investigated. Immersion tests were performed to evaluate the impact of pH on the degradation of the specimens in an aqueous environment. The specimens were soaked in aqueous solutions of pH 4.

Effect of incorporation of surface pre-reacted glass ionomer filler in tissue conditioner on the inhibition of Candida albicans adhesion.

We investigated the effects of incorporation of surface pre-reacted glass ionomer (S-PRG) filler in tissue conditioner (TC) on Candida albicans adhesion. We prepared specimens containing 0, 5, 10, or 20 wt% of S-PRG filler, and measured the amount of C. albicans on the surface using a colony forming unit (CFU) assay and scanning electron microscopic images.

Shape Optimization of Bone-Bonding Subperiosteal Devices with Finite Element Analysis.

Subperiosteal bone-bonding devices have been proposed for less invasive treatments in orthodontics. The device is osseointegrated onto a bone surface without fixation screws and is expected to rapidly attain a bone-bonding strength that successfully meets clinical performance. Hence, the device's optimum shape for rapid and strong bone bonding was examined in this study by finite element analyses.

Enhanced biological fixation of ligaments to bone tissues utilizing chitin fabrics.

In ligament reconstruction involving anterior cruciate ligament surgery, biological fixation between the transferred ligament and bone tissue is critical for achieving successful outcomes. Here, we administered chitin fabrics into the bone tunnels and evaluated their efficacy in promoting biological fixation. An animal model on the rat's patellar ligament was employed.

Wound healing efficacy of a 660-nm diode laser in a rat incisional wound model.

This study aimed to elucidate the optimum usage parameters of low reactive-level laser therapy (LLLT) in a rat incisional wound model. In Sprague-Dawley rats, surgical wounds of 15-mm length were made in the dorsal thoracic region. They were divided into groups to receive 660-nm diode laser irradiation 24 h after surgery at an energy density of 0 (control), 1, 5, or 10 J/cm.

Impact of Dynamic and Static Load on Bone Around Implants: An Experimental Study in a Rat Model.

Purpose: This study aimed to evaluate peri-implant bone reactions to dynamic and static loads in a rat model.

Materials And Methods: Two cylindrical titanium implants were placed in the left tibia diaphysis of 39 rats, which were divided into three groups: static load for 4 weeks (S4), static load for 8 weeks (S8), and static load for 4 weeks followed by dynamic load for 4 weeks (S4D4). All implants received a mechanical lateral load.

Comparison of nerve regenerative efficacy between decellularized nerve graft and nonwoven chitosan conduit.

Background: Recently decellularized nerves with various methods are reported as highly functional nerve grafts for the treatment of nerve defects.

Objective: To evaluate the efficacy of decellularized allogeneic nerve, compared with oriented chitosan mesh tube, and an autologous nerve.

Methods: Sciatic nerves harvested from Sprague-Dawley (SD) rats were decellularized in combination with Sodium dodecyl sulfate and Triton X-100.

Reduction of Candida biofilm adhesion by incorporation of prereacted glass ionomer filler in denture base resin.

Objectives: This study investigated the influence of surface reaction-type prereacted glass ionomer (S-PRG) fillers on Candida albicans adhesion on denture base resin.

Methods: Discs were prepared by incorporating the S-PRG filler into the polymer powder of a polymethyl methacrylate (PMMA)-based, heat-polymerizing resin at 0 (control), 5%, 10%, and 20% (w/w). The surface roughness of all disc surfaces was measured.

In vivo evaluation of a Ti-based bulk metallic glass alloy bar.

Ti-based bulk metallic glasses are reported with high strength, low Young modulus and high corrosion resistance, suggesting their potentials in biomedical applications. However a thorough in vivo evaluation of its biocompatibilities has not been conducted yet. In this study, we implanted bars of Ti-based bulk metallic glass in the femoral bone of rats, followed up local tissue reaction as well as its component ions' diffusion in local area and whole body.

Comparative study of the efficacy of decellularization treatment of allogenic and xenogeneic nerves as nerve conduits.

The objective of this study was to compare the results of allogenic and xenogeneic nerve grafts that were treated using decellularization. The sciatic nerves of Sprague-Dawley rats and the median nerves of Japanese white rabbits were decellularized with sodium dodecyl sulfate and Triton X-100 and examined with a scanning electron microscope and immunofluorescence staining. A bridge-graft into the sciatic nerve in Wistar rats was performed with the decellularized nerves (10 mm in length for short-term evaluation; 15 mm in length for long-term evaluation).

An Experimental Study to Bridge a Nerve Gap with a Decellularized Allogeneic Nerve.

Background: The authors evaluated the efficacy of decellularized nerve as a scaffold for nerve regeneration.

Methods: Sciatic nerves harvested from Sprague-Dawley rats were decellularized in combination with sodium dodecyl sulfate and Triton X-100, and examined with scanning electron microscopy and immunofluorescence staining. A graft into the sciatic nerve in Wistar rats was performed with the decellularized Sprague-Dawley rat sciatic nerves [allograft: 10 mm long (n = 3) for short term and 15 mm long (n = 5) for long term].

Synovial mesenchymal stem cells promote healing after meniscal repair in microminipigs.

Objective: The induction of synovial tissue to the meniscal lesion is crucial for meniscal healing. Synovial Mesenchymal stem cells (MSCs) are an attractive cell source because of their high proliferative and chondrogenic potentials. We examined whether transplantation of synovial MSCs promoted healing after meniscal repair of extended longitudinal tear of avascular area in a microminipig model.

Reconstruction of small diameter arteries using decellularized vascular scaffolds.

Although artificial vessels are available for large diameter arteries, there are no artificial vessels for small diameter arteries of < 4 mm. We created a decellularized vascular scaffold (length, 10 mm; outer diameter, 1.5 mm; inner diameter, 1.

Development of oral and extra-oral endosseous craniofacial implants by using a mesh structure for connective tissue attachment.

Connective tissue attachment to a mesh structure incorporated on the surface of oral implants and extra-oral endosseous craniofacial implants (EOECI) was investigated. Two types of implants were prepared: TI and TI-Mesh. TI was composed of an upper and a lower component, both comprised of a titanium cylinder, which could be connected using a titanium screw.

Laser perforated accordion nerve conduit of poly(lactide-co-glycolide-co-ɛ-caprolactone).

Accordion nerve conduit of poly(lactide-co-glycolide-co-ε-caprolactone) with perforations was developed by excimer laser processing. We evaluated its in vivo function for nerve repairing and discussed the influence of pore size and density. It was found that perforations help inner nerve regeneration remarkably, which effect is unrelated to pore size or density, and is not parallel with revascularization increment.

Enhanced osteoconductivity of titanium implant by polarization-induced surface charges.

This study introduces the application of method for electrically polarizing titanium implants coated with anatase TiO2 using microarc oxidation. It also describes the features of the electrically polarized titanium implants, on which surface charges are generated by the dipole moment of the TiO2 , and describes how the surface charges affect the implants' in vivo bone-implant integration capability. A comprehensive assessment using biomechanical, histomorphological, and radiographic analyses in a rabbit model was performed on polarized and nonpolarized implants.

Hydroxyapatite/collagen nanocomposite-coated titanium rod for achieving rapid osseointegration onto bone surface.

This article proposes less-invasive subperiosteal bone-bonding devices capable of realizing rapid osseointegration and the acquisition of fundamental knowledge required for their development. Three candidates were prepared: titanium rod specimens with a machined surface (Bare), hydroxyapatite (HAp) coating, and hydroxyapatite/collagen (HAp/Col) nanocomposite coating. To investigate bone formation around these rods, each specimen was placed under the periosteum of a male Sprague-Dawley rat calvarium.

Mechanical attachment of soft tissue to dental and maxillofacial implants with mesh structures: an experiment in percutaneous model.

Soft tissue attachment is a major concern for the improved design of dental and maxillofacial implants. This study evaluated the efficacy of mesh structures for soft tissue attachment in a rat percutaneous model. Four kinds of implant specimens were prepared - TI implants made of titanium cylinders, HA implants of hydroxyapatite-coated titanium, TI-Mesh implants with a titanium mesh covering a groove machined around a titanium cylinder, and similar HA-Mesh implants with a hydroxyapatite-coated mesh.

Remodeling of actin cytoskeleton in mouse periosteal cells under mechanical loading induces periosteal cell proliferation during bone formation.

Background: The adaptive nature of bone formation under mechanical loading is well known; however, the molecular and cellular mechanisms in vivo of mechanical loading in bone formation are not fully understood. To investigate both mechanisms at the early response against mechanotransduction in vivo, we employed a noninvasive 3-point bone bending method for mouse tibiae. It is important to investigate periosteal woven bone formation to elucidate the adaptive nature against mechanical stress.

Preparation and in vitro/in vivo evaluations of dimpled poly(L-lactic acid) fibers mixed/coated with hydroxyapatite nanocrystals.

A novel hydroxyapatite (HAp)/poly(L-lactic acid) (PLLA) nanocomposite nonwoven fabric, which was coated and mixed with calcined HAp nanocrystals, and has submicron-sized dimples on its surface, was fabricated. First, HAp-mixed PLLA fabric was prepared by electrospinning a HAp nanocrystal dispersion in dichloromethane (DCM)-dissolved PLLA. It was found that most of the HAp nanocrystals were not exposed on the HAp-mixed PLLA fiber surface but covered with the PLLA matrix.

Reproducibility of probing depth measurement by an experimental periodontal probe incorporating optical fiber sensor.

Background: An experimental periodontal sensor probe (SP) equipped with an optical fiber for recording function was developed. The aim was to test the intraexaminer reproducibility of probing using the SP and to assess the consistency with the manual probe (MP).

Methods: The SP was assembled with an external sheath covering the probe tip of an MP.

Collagen fiber anchoring platforms for percutaneous devices.

In this study, we investigated the use of perforated sheet platforms to improve the attachment of percutaneous devices to surrounding tissues. The model platform was created by a poly(methyl methacrylate) (PMMA) sheet with a matrix of 200-microm diameter perforations covering the groove (width, 3 mm; depth, 0.5 mm) prepared on the PMMA cylinder (diameter, 10 mm; length, 6 mm).