In Vitro Evaluation of the Antibacterial Properties of Tea Tree Oil on Planktonic and Biofilm-Forming Streptococcus mutans.

Streptococcus mutans (S. mutans) is the principal etiologic agent in the occurrence of human dental caries and the formation of biofilms on the surface of teeth. Tea tree oil (TTO) has been demonstrated to exhibit a wide range of pharmacological actions that can effectively inhibit the activity of bacteria.

Exogenous nitric oxide stimulates the odontogenic differentiation of rat dental pulp stem cells.

Nitric oxide (NO) is thought to play a pivotal regulatory role in dental pulp tissues under both physiological and pathological conditions. However, little is known about the NO functions in dental pulp stem cells (DPSCs). We examined the direct actions of a spontaneous NO gas-releasing donor, NOC-18, on the odontogenic capacity of rat DPSCs (rDPSCs).

Structure and Properties of La(2)O(3)-TiO(2) Nanocomposite Films for Biomedical Applications.

The hemocompatibility of La(2)O(3)-doped TiO(2) films with different concentration prepared by radio frequency (RF) sputtering was studied. The microstructures and blood compatibility of TiO(2) films were investigated by scan electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-visible optical absorption spectroscopy, respectively. With the increasing of the La(2)O(3) concentrations, the TiO(2) films become smooth, and the grain size becomes smaller.

Sequential expression of endothelial nitric oxide synthase, inducible nitric oxide synthase, and nitrotyrosine in odontoblasts and pulp cells during dentin repair after tooth preparation in rat molars.

Nitric oxide (NO) stimulates osteoblast differentiation, but whether NO contributes to odontoblast differentiation during dentin repair is unknown. By using reverse transcription/polymerase chain reaction and immunostaining, we investigated the gene expression and/or immunolocalization of endothelial NO synthase (eNOS), inducible NOS (iNOS), and nitrotyrosine (a biomarker for NO-derived peroxinitrite), and alkaline phosphatase (ALP) and osteocalcin (early and terminal differentiation markers of odontoblasts, respectively) in dental pulp tissue after rat tooth preparation. At the early stage (1-3 days) post-preparation, markedly increased expression of iNOS and nitrotyrosine was found in odontoblasts and pulp cells beneath the cavity, whereas eNOS expression was significantly decreased.

Expression of osteocalcin and Jun D in the early period during reactionary dentin formation after tooth preparation in rat molars.

We examined, in rats, the expression of osteocalcin and Jun D in the early stage of reactionary dentin formation after tooth preparation and the accompanying morphological changes. Reverse transcription/polymerase chain reaction analysis revealed strong expression of osteocalcin mRNA in pulp tissue at 2 and 3 days post-preparation compared with that in control teeth. Light microscopy demonstrated that, at the dentin-pulp interface, damaged odontoblasts were detached from the dentin matrix immediately after preparation, with neutrophils lining the dental surface after 1 day.