Effects of laser irradiation on tensile strength of bovine dentin.

Objective: The purpose of the present study was to investigate the tensile strengths of dentin after laser irradiation using three kinds of dental lasers to elucidate the laser-irradiation effect on dentin properties.

Background Data: Different kinds of laser devices have been developed in dentistry. The characteristics of each laser are determined by its original wavelength; however, one common feature is to generate heat in irradiated tissues, and such heat possibly affects dentin collagen, which contributes to tensile strength of the tissues.

Reactive hyperemia following coronary balloon angioplasty, but not dipyridamole-induced hyperemia, predicts resolution of exercise-induced ST-segment depression.

Objectives: To characterize delayed restoration of coronary blood flow following successful percutaneous transluminal coronary angioplasty (PTCA).

Background: Delayed restoration of coronary blood flow following successful PTCA is common and likely the result of multiple factors. Temporary myocardial ischemia and dipyridamole administration both result in increased coronary blood flow, but by different mechanisms.

Advancing age is associated with diminished vascular remodeling and impaired vasodilation in resistance coronary arteries.

Background: Compensatory enlargement of the coronary arterial wall has been described in the early stages of native atherosclerosis. However, little is known about the specific effect of aging on this adaptive process in atherosclerosis. The purpose of the current study was to characterize the effects of advancing age on vascular remodeling and endothelium-dependent and -independent coronary vasodilation in patients without coronary artery disease risk factors.

A new predictor of improvement in regional left ventricular function assessed by ST/HR slope derived from ST elevation on exercise testing in patients with healed myocardial infarction.

This study evaluates the clinical usefulness of ST/HR slope derived from ST elevation on exercise to predict the improvement in regional wall motion following coronary revascularization in patients with healed myocardial infarction. We studied 58 patients with a diseased, infarct-related and single-vessel coronary artery. The decline calculated from the final 12 data points relating ST-segment elevation to heart rate during exercise were derived (ST/HR slope).