The mechanical strength of the periodontal ligament (PDL) was first measured as force required to extract a tooth from its socket using human specimens. Thereafter, tooth-PDL-bone preparations have extensively been used for measurement of the mechanical response of the PDL. In vitro treatments of such specimens with specific enzymes allowed one to investigate into the roles of the structural co...

Residual periodontal ligament (PDL) and cement mass on the roots of extracted teeth are factors that considerably affect tooth transplantation. Therefore, when normal extracted teeth are used for autologous transplantation, it is necessary to regenerate the PDL of the root surface. Here we describe a method to examine human PDL cell adhesion on sterilized root surfaces. Sample teeth were extrac...

BACKGROUND Pulsed dye laser (PDL) is a commonly utilized treatment for port wine stain birthmarks (PWS) in the United States; however, results are variable and few patients achieve complete removal. Photodynamic therapy (PDT) is commonly used in China, but treatment associated photosensitivity lasts several weeks and scarring may occur. We propose an alternative treatment option, combined PDT+P...

BACKGROUND AND OBJECTIVES Previous in vitro studies demonstrated the potential utility of benzoporphyrin derivative monoacid ring A (BPD) photodynamic therapy (PDT) for vascular destruction. Moreover, the effects of PDT were enhanced when this intervention was followed immediately by pulsed dye laser (PDL) irradiation (PDT/PDL). We further evaluate vascular effects of PDT alone, PDL alone and P...

Gingival and periodontal ligament (PDL) fibroblasts are the major cellular components of periodontal soft connective tissues, but the precise differences between these cells are not yet known. In the present study, we have therefore examined the phenotypic and functional features of the cells obtained from gingival and PDL biopsy samples. Spindle-shaped cells characteristic of fibroblasts were ...

The paper describes a support tool for learners engaged in elearning, the Personal Digital Library (PDL). The characteristics and functionality of the PDL are presented. Suggested steps for constructing and managing a PDL are outlined and discussed briefly. The authors believe that the PDL as a support tool of e-learning will be important and essential in the future.

The periodontal ligament (PDL) is a soft biological tissue which shows a strongly nonlinear and time dependent mechanical behavior. Recent experiments on rabbit PDL revealed that the rate of stress relaxation is strain dependent. This nonlinear behavior of PDL cannot be described well by the separable quasi linear viscoelasticity theory which is usually used in tissue biomechanics. Therefore, P...

Although best characterized for sustaining T cell exhaustion during persistent viral infection, programmed death ligand-1 (PDL-1) also stimulates the expansion of protective T cells after infection with intracellular bacterial pathogens. Therefore, establishing the molecular signals that control whether PDL-1 stimulates immune suppression or activation is important as immune modulation therapie...