Effect of mouth-opening levels on sound field gain in the ear canal.

The human external auditory canal can become deformed when the mandible moves, and this changes the sound field in the external auditory canal. This study measured the sound field gain in the external auditory canal while varying mouth-opening in three levels. The mandible was fixed at the 1/3, the 2/3, and the maximal mouth-opening levels.

Areca nut components stimulate ADAM17, IL-1α, PGE2 and 8-isoprostane production in oral keratinocyte: role of reactive oxygen species, EGF and JAK signaling.

Betel quid (BQ) chewing is an etiologic factor of oral submucous fibrosis (OSF) and oral cancer. There are 600 million BQ chewers worldwide. The mechanisms for the toxic and inflammatory responses of BQ are unclear.

Role of ALK5/Smad2/3 and MEK1/ERK Signaling in Transforming Growth Factor Beta 1-modulated Growth, Collagen Turnover, and Differentiation of Stem Cells from Apical Papilla of Human Tooth.

Introduction: Transforming growth factor β1 (TGF-β1) plays an important role in cell proliferation, matrix formation, and odontogenesis. This study investigated the effects of TGF-β1 on stem cells from apical papilla (SCAPs) and its signaling by MEK/ERK and Smad2.

Methods: SCAPs were exposed to TGF-β1 with/without pretreatment and coincubation by SB431542 (an ALK5/Smad 2/3 inhibitor) or U0126 (a MEK/ERK inhibitor).

p-Cresol affects reactive oxygen species generation, cell cycle arrest, cytotoxicity and inflammation/atherosclerosis-related modulators production in endothelial cells and mononuclear cells.

Aims: Cresols are present in antiseptics, coal tar, some resins, pesticides, and industrial solvents. Cresol intoxication leads to hepatic injury due to coagulopathy as well as disturbance of hepatic circulation in fatal cases. Patients with uremia suffer from cardiovascular complications, such as atherosclerosis, thrombosis, hemolysis, and bleeding, which may be partly due to p-cresol toxicity and its effects on vascular endothelial and mononuclear cells.

Influence of cyclic heating on physical property and biocompatibility of α- and β-form gutta-percha.

Background/purpose: Thermoplasticized techniques with high temperature and repetitive heating in root canal filling may cause degeneration of gutta-percha, producing cytotoxic byproducts and interfering sealing quality. This study was conducted to investigate the influence of cyclic heating on the physical property and biocompatibility of α- and β-form gutta-perchas.

Methods: Both α- and β-form gutta-perchas were submitted to two heating processes: continuous heating and cyclic heating.

Areca nut-induced buccal mucosa fibroblast contraction and its signaling: a potential role in oral submucous fibrosis--a precancer condition.

Betel quid (BQ) chewing is an oral habit that increases the risk of oral cancer and oral submucous fibrosis (OSF), a precancerous condition showing epithelial atrophy and tissue fibrosis. Persistent fibroblast contraction may induce the fibrotic contracture of tissue. In this study, we found that areca nut extract (ANE) (200-1200 µg/ml) stimulated buccal mucosa fibroblast (OMF)-populated collagen gel contraction.

Repair of perforating internal resorption with mineral trioxide aggregate: a case report.

A case of internal resorption with buccal perforation was found in a maxillary central incisor. Because of the extensive lesion and continuous exudation, surgical intervention was used. The apical third was obturated with gutta-percha, and the perforated lesion was repaired with mineral trioxide aggregate.