The Wear Behavior of Glass-Ceramic CAD/CAM Blocks against Bovine Enamel.

The wear of enamel and crown restorative materials often occur by occlusion. The purpose of this study was to evaluate the wear volume between glass-ceramics used for CAD/CAM blocks (lithium disilicate: Initial LiSi block (LIS), IPS e.max CAD (IPS), zirconia-reinforced lithium silicate glass-ceramics: Celtra DUO (DUO), VITA Suprinity (VITS) and feldspar-based glass-ceramics: Vitablocs Mark II (MAK)) and bovine tooth enamel using a two-body wear test, the hardness, three-point bending strength, micro-structure and the element components of glass-ceramics.

Effect of the Correction of Bilateral Differences in Masseter Muscle Functional Pressure on the Mandible of Growing Rats.

The objective of this study is to clarify the effect of restoring the lowered masticatory muscle functional pressure and correcting bilateral differences in masticatory muscle functional pressure on jawbone growth during growth and development with a quantitative evaluation of the changes in the micro/nanostructural characteristics of entheses. Male Wistar rats aged 4 weeks were divided into an experimental group injected with a botulinum toxin serotype A (BoNT/A) formulation to reduce muscle function (BTX group) and a control group (CTRL group). They were euthanised after 6, 8, 10, 12, and 16 weeks after measuring the difference between the midline of the upper and lower incisors.

Alveolar Bone Microstructure Surrounding Orthodontic Anchor Screws with Plasma Surface Treatment in Rats.

A lateral load was applied to anchor screws that had undergone surface treatment, and the structure, cellular dynamics, and quality of the bone surrounding anchor screws were analyzed to investigate the effect of this surface treatment on the peri-implant jawbone. In addition, bone microstructural characteristics were quantitatively evaluated for each site of loading on the bone around the anchor screw. Rats were euthanized after observation on days 3, 5, or 7, and bone quality analyses were performed.

The effects of orthodontic anchor screw inserted into the femur of growth-phase or mature rats -Osteoid formation, bone mineral density, collagen fiber bundles, biological apatite crystal orientation.

The purpose of this study is to investigate the effect of orthodontic anchor screws (OASs) inserted into the femur of growth-phase or mature rats using histological observation and bone structure analysis. The experimental animals are growth-phase (6-week-old) or mature (25-week-old) male Wistar rats. OAS was placed into the point one-third of the femoral length from the proximal end of the femur, and the response of the surrounding bone was observed and measured.

Effect of Surface Treatments of Polyetherketoneketone as a Post Material on Shear Bond Strength to Root Dentin using Two Types of Resin Cement.

Purpose: This study investigated the effects of mechanical and chemical pretreatment of polyetherketoneketone (PEKK) on shear bond strength (SBS) to root dentin using two types of resin cement.

Materials And Methods: A total of 100 PEKK specimens were prepared and polished. Sixty specimens were mechanically treated by sandblasting (50-µm Al2O3 for 10 s at 0.

Effects of hollow structures added by selective laser sintering on the mechanical properties of Co-Cr alloy.

Purpose: This study investigates the effects of hollow structures, added by selective laser sintering (SLS), on the mechanical properties of a Co-Cr alloy for providing an optimal structural property to the framework components of removable partial dentures (RPDs).

Methods: The specimens produced using the 3D data of the dumbbell-shaped cylinders were divided into four groups based on the manufacturing method: Cast, Mill, SLS-solid, and SLS-hollow. Tensile tests were performed to measure the mechanical properties of the specimens.

Effect of bone defect width and a ferrule on the fracture characteristics of vertically fractured teeth reattached with adhesive resin cement: An in vitro study.

This study aimed to clarify the effects of vertical bone defect width and a ferrule on fracture of the fragments of fractured tooth reattached with adhesive resin cement (reattached tooth). The reattached tooth was built up by a fiber post and composite resin core for abutment and formed to the abutment with or without a ferrule. The vertical bone defect was fabricated with a V-shaped defect in different widths.

Structural characteristics of the bone surrounding dental implants placed into the tail-suspended mice.

Background: There are many unclear points regarding local structural characteristics of the bone surrounding the implant reflecting the mechanical environment.

Purpose: The purpose of this study is to quantitatively evaluate bone quality surrounding implants placed into the femurs of mice in an unloading model, and to determine the influence of the mechanical environment on bone quality.

Methods: Twenty 12-week-old male C57BL6/NcL mice (n = 5/group) were used as experimental animals.

Retention force of fiber-reinforced composite resin post on resin composite for core buildup -Effects of fiber orientation, silane treatment and thermal cycling.

The purpose of this study was to investigate the effects of fiber orientation, silane treatment, and thermal cycling on the retention force of fiber-reinforced composite resin (FRC) posts on resin composite. Two types of FRC posts (linear and woven) were prepared with and without silane treatment. Pull-out test specimens were made of FRC posts and resin composite for core buildup.

Severe Hydroxyapatite Deposition Disease in Binturongs (Arctictis ).

In a collection of 6 young binturongs (), 3 presented with anorexia, lethargy, and footpad swelling diagnosed by surgical biopsy as calcinosis circumscripta. Despite supportive care over the next 4 years, affected binturongs had progressive weight loss, hyperphosphatemia, and hyperkalemia and developed large radiodense deposits in tissues adjacent to appendicular joints, thoracolumbar vertebrae, and the sternum. Two binturongs died and necropsies showed severe periarticular mineral deposition with fibrosis and granulomatous inflammation.

Localization of T-cell factor 4 positive fibroblasts and CD206-positive macrophages during skeletal muscle regeneration in mice.

Skeletal muscle regeneration is initiated by the activation of the transcription factor paired box 7 (Pax7), which is expressed in the satellite cells. The nuclear transcription factor T-cell factor 4 (Tcf4) is expressed in the fibroblasts and is involved in muscle tissue repair, while M2-like macrophages play an important role in skeletal muscle regeneration. However, the localization of M2-like macrophages and the expression of Tcf4 over a period of time during skeletal muscle regeneration remain unknown.

Micro- and nano-bone analyses of the human mandible coronoid process and tendon-bone entheses.

The coronoid process provides attachment to temporalis and masseter muscles, and thus plays an important role in mastication. Tendons connect muscles and bones, mediating the transmission of functional loads to bones. Thus, tendon-bone entheses govern mechanical stress in bones.

Effect of Mesenchymal Cells on Myoblast Sheets Embedded in Collagen Gel.

The objective of this study was to investigate the effects of mesenchymal cells on myoblasts in long-term cultivation of myoblast cell sheets. Sheets of myoblasts and mesenchymal cells from Japanese rabbit oral mucosa were generated and analyzed by histochemistry, Western blot, and reverse transcription-polymerase chain reaction. The presence of desmin and type IV collagen, which is seen in normal muscle tissue, was also confirmed in all the sheets produced.

Anatomic and Histological Study of Lingual Nerve and Its Clinical Implications.

Although the risk of injuring the lingual nerve in the mandibular molar area during dental treatment is high, it can be repaired by nerve grafting. However, from the perspective of clinical dentistry, the pathway and histomorphometric characteristics of this nerve remain to be documented in detail. The purpose of the present study was to morphologically elucidate the pathway of the lingual nerve to clarify its significance in a clinical setting.

Regional Anatomical Observation of Morphology of Greater Palatine Canal and Surrounding Structures.

In maxillary molar region implant therapy, support is sometimes obtained from trabecular bone comprising the maxillary tuberosity, pterygoid process of the sphenoid bone, and pyramidal process of the palatine bone. Great care is necessary in such cases due to the presence of the greater palatine canal, which forms a passageway for the greater palatine artery, vein, and nerve. However, clinical anatomical reports envisioning embedding of pterygomaxillary implants in this trabecular bone region have been limited in number.

Three-dimensional analysis of incisive canals in human dentulous and edentulous maxillary bones.

Background: The purpose of this study was to reveal the structural properties that need to be considered in dental implant treatment by investigating differences between dentulous and edentulous maxillae in the three-dimensional (3D) microstructure of the incisive canals (ICs) and their surrounding bone.

Methods: A total of 40 maxillary bones comprising 20 dentulous maxillae and 20 edentulous maxillae were imaged by micro-CT for 3D observation and measurement of the IC and alveolar bone in the anterior region of the IC.

Results: The Y-morphology canal was most frequently observed at 60% in dentulous maxilla and 55% in edentulous maxilla.

Sympathetic and parasympathetic neurons are likely to be absent in the human vestibular and geniculate ganglia: an immunohistochemical study using elderly cadaveric specimens.

The vestibular and geniculate ganglia of the ear in experimental animals carry both of the tyrosine hydroxylase (TH)-positive sympathetic neurons and the neuronal nitric oxide synthase (nNOS)-positive parasympathetic neurons. With an aid of immunohistochemistry, we examined these ganglia as well as the horizontal part of the facial nerve using specimens from 10 formalin-fixed elderly cadavers. The submandibular ganglion from the same cadavers was used for the positive control for both markers.

Macrophage density in pharyngeal and laryngeal muscles greatly exceeds that in other striated muscles: an immunohistochemical study using elderly human cadavers.

Macrophages play an important role in aging-related muscle atrophy (i.e., sarcopenia).

Synovial tissue morphology of the cricoarytenoid joint in the elderly: a histological comparison with the cricothyroid joint.

We compared the age-related morphology of the cricothyroid (CT) joint with that of the cricoarytenoid (CA) joint using 18 specimens from elderly cadavers in terms of their elastic fiber contents as well as the cells composing the joint capsule and synovial tissues. In contrast to an almost flat-flat interface in the CT joint, the CA joint was similar to a saddle joint. The CA joint capsule was thin and contained few elastic fibers, and in contrast to the CT joint, external fibrous tissues were not exposed to the joint cavity, there being no injury to the CA joint capsule.

Histological study of the developing pterygoid process of the fetal mouse sphenoid.

The pterygoid process undergoes ossification of both the cartilage and membrane. However, few studies have attempted to explore the sequential development of the pterygoid process. Using histological examination, we performed morphological observations of the pterygoid process and surrounding tissue.

Regional differences in the density of Langerhans cells, CD8-positive T lymphocytes and CD68-positive macrophages: a preliminary study using elderly donated cadavers.

To provide a better understanding of the local immune system in the face and external genitalia, i.e., the oral floor, lower lip, palpebral conjunctiva, anus and penis, we examined the distribution and density of CD1a-positve Langerhans cells, CD8-positive suppressor T lymphocytes and CD68-positive macrophages using specimens from 8 male elderly cadavers.

Innervation of submandibular and sublingual glands in elderly donated cadavers: a preliminary histological study of differences in nerve morphology between mucous and serous acini.

We examined morphological differences between the sublingual and submandibular glands with special reference to their innervation. The sublingual gland contained abundant periodic acid Schiff-positive mucous acini: some lobules were composed of purely mucous acini, while others were purely serous or mixed. However, in the submandibular gland, the area of mucous acini was very limited.

Variation of the subscapularis tendon at the fetal glenohumeral joint.

We examined the topohistology of the subscapularis tendon at the glenohumeral joint in 10 mid-term (15-16 weeks of gestation) and 10 late-stage (27-32 weeks) human fetuses. At both stages, there were two patterns of terminal course of the subscapularis tendon: 1) the tendon was tightly attached to the medial part of the joint capsule and extended anterosuperiorly along the capsule to the lesser tubercle (7/10 mid-term fetuses; 5/10 late-stage fetuses); 2) the tendon passed superiorly through the joint cavity for a long distance in combination with the subcoracoid bursa opening widely to the joint cavity (3/10 mid-term fetuses; 5/10 late-stage fetuses). The lower glenoid labrum tended to be well developed in the former pattern because the subscapularis tendon did not interfere with the superior extension of the labrum.

Distribution of elastic fibers in the head and neck: a histological study using late-stage human fetuses.

There is little or no information about the distribution of elastic fibers in the human fetal head. We examined this issue in 15 late-stage fetuses (crown-rump length, 220-320 mm) using aldehyde-fuchsin and elastica-Masson staining, and we used the arterial wall elastic laminae and external ear cartilages as positive staining controls. The posterior pharyngeal wall, as well as the ligaments connecting the laryngeal cartilages, contained abundant elastic fibers.