Catálogo de publicaciones - libros

Accelerating the speed of orthodontic tooth movement should contribute to the shortening of the treatment period, which is one of the unfavorable aspects of orthodontic treatment. This study developed the resonance vibration delivery system and evaluated the effects of resonance vibration on tooth movement, and revealed the cellular and molecular mechanisms of the periodontal ligament responses. The application of resonance vibration might accelerate orthodontic tooth movement via enhanced receptor activator of nuclear factor kappa B ligand expression in the periodontal ligament without additional damage to periodontal tissues, such as root resorption.

We examined the immunohistochemical localization and isolation of mesenchymal stem cells in human wisdom tooth germs. Pericytes of blood vessels in the dental papilla and ameloblasts were stained strongly, but odontoblasts reacted weakly with STRO-1 and CD146. The STRO-1 positive cells represented approximately 7% of the total cell population. It is suggested that human wisdom tooth germs are useful for the stem cell treatment and the tissue engineering.

The aim of this study is to examine whether the in vitro application of mechanical stress would induce apoptosis in cultured human osteoblastic cell line MG-63 cells and/or human primary periodontal ligament (PDL) cells. Cells were subjected to continuous compressive force directly. As a result, in vitro compressive force induces apoptosis via caspase-8 activation in osteoblasts, while PDL cells did not show a significant change. The cell-type-specific cell-death reaction may regulate periodontal remodeling at sites where excessive compressive force is applied during orthodontic tooth movement.

The purpose of this study was to determine whether a selective cyclooxygenase-2 inhibitor, celecoxib, could control osteopenia and increased bone turnover associated with ovariectomy in rats. Female Sprague-Dawley rats were subjected to either bilateral ovariectomy (OVX) or sham surgery (Sham). Sham and OVX rats were treated daily with vehicle alone or celecoxib (20 mg/kg) for 5 weeks. When determined by peripheral quantitative computed tomography (pQCT), celecoxib had no apparent effects on osteopenia induced by OVX. However, it inhibited osteoclast differentiation and bone resorption at a serum marker level. These results suggest that celecoxib could be used as a therapeutic agent for bone metabolic disorders such as osteoporosis.

Isoforms of amelogenin, a highly conserved protein in mammalians that constitutes 90% of the enamel organic matrix, are mainly produced by ameloblasts. One of the amelogenin splicing variants, leucine rich amelogenin peptide (LRAP) has been reported to promote maturation of osteoblasts and periodontal ligament (PDL) cell proliferation. However, it is still unclear whether the amelogenin splicing variants are involved in chondrogenesis. The aim of the present study was to characterize the function of LRAP in chondrogenesis. Micromass culture of embryonic limb bud mesenchymal cells was performed as in vitro model for chondrogenesis. The recombinant LRAP was added to micromass culture system to analyze the effect on proliferation of mesenchymal cells and chondrogenic differentiation. LRAP increased the number of 5-bromo-2-deoxyuridine (BrdU) positive cells and nodules stained with alcian blue. In addition, LRAP increased mRNA expression of Sox9 and type II collagen. These findings suggest that the amelogenin splicing variant, LRAP, promotes chondrogenesis.

The relationship between the laser Doppler blood-flow signals and the laser light intensity in the root canal was examined. The root canals of extracted teeth were enlarged from the apical end to the 2 mm incisal to the level of the cement-enamel junction (CEJ). Human peripheral blood was pumped through the apical foramen of the teeth, and the blood flow signal was monitored. Both the light intensities in the root canal and pulpal blood-flow (PBF) signals were small when the root canal was enlarged 3 or 4 mm apical to the CEJ. Both intensities increased with the progress of root canal enlargement to the tooth. There was a significant relationship between the laser Doppler blood-flow signals and the light intensity in the root canals. The results indicated that the laser light intensity in the root canal effected on the PBF in human teeth using Laser Doppler flowmetry (LDF).

The purpose of this study was to examine the relation between the root resorption and the pulpal blood flow (PBF) in human primary teeth using laser Doppler flowmeter (LDF). Recordings were made on 15 clinically healthy upper primary central incisors in nine healthy participants (age: 3 years 11 months-7 years 3 months). The state of roots of the teeth examined were confirmed by radiographs. The mean PBF signals tended to decrease with the progress of the root resorption. Results indicated that PBF could indicate the status of the root resorption in the human primary teeth.

This study was designed to determine if sympathetic nerve fibers exist in dentinal tubules in rat normal dental pulp, and if they sprout into the tubules in the inflamed condition. Sympathetic nerve fibers in rat molar dental pulp were labeled using an anterograde axonal transport technique involving injection of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) into the superior cervical ganglion. In the normal dental pulp, scattered WGA-HRP reaction products were observed in unmyelinated nerve endings in odontoblast layer and subodontoblastic region, mostly close to odontoblast cell bodies. More reaction products were detected in the above areas in the inflamed dental pulp than that in the normal pulp. However, no labeled nerve fibers were observed in dentinal tubules in either normal or inflamed dental pulp. These results indicate that although sympathetic nerve fibers do indeed sprout in inflamed dental pulp, they do not penetrate into the dentinal tubules.

The mastication is not only related with the peripheral function, but also the central control system. The purpose of this study was to clarify the interface between the brain function and the occlusion by investigating the stimulation of the frontal association cortex, which relates to the function of the human nature. Subjects were healthy right-handed young adult volunteers with acceptable normal occlusion and class III malocclusion. Near-infrared spectroscopic topography (NIRS) was used to investigate the stimulation of the frontal association cortex during chewing gum without flavors. It was proved that the frontal association cortex was also stimulated by chewing gum. However, the behavior of the stimulation depended on the individual occlusion type. This study suggests that orthodontic treatment would improve the quality of life (QOL) of patients from the point of healthy brain function.

Pain is one of the most important factors in dentistry. Objective measurement of pain may be useful for dental diagnosis and therapy. However, until now, we have had no modality to measure the location and degree of pain objectively. The purpose of this study is to measure reactions to pain in cerebral cortex during dental treatment using Cerebral functional mapping of Oxygen Exchange (COE), and to assess the application of COE in the field of dentistry. We obtained the following results: (1) reactions in cerebral cortex apparently related to dental pain were measured at Brodmann’s area 10, (2) COE measurement responses were sensitive and reactions could be shown within a few seconds during an event, and (3) the reactions also disappeared quickly after the pain disappeared.