Relationship between gap width and recurrent dental caries beneath occlusal margins of amalgam restorations.

This study examines the relationship between gap width and the presence of recurrent dental caries subjacent to occlusal margins of amalgam restorations. The study population consisted of 35 adult patients of the university's dental clinic who were having occlusal amalgam restorations removed solely because of defective margins. In this group, an impression was made recording the width of a clinically detected gap between the amalgam restoration and the adjacent enamel cavosurface.

Optimal etching time of glass ionomer cement for maximum bond of composite resin.

This study compares the bond strengths of a composite resin to a glass ionomer cement with two types of surfaces and four etching times and attempted to correlate the bond strengths with a scanning electron microscope (SEM). The bond strengths were significantly greater to the instrumented surface at all etching times and the composite resin would not bond to glass smooth, unetched glass ionomer.

Anxiolytic effects of low dosage nitrous oxide-oxygen mixtures administered continuously in apprehensive subjects.

We observed the effect of low doses of nitrous oxide on the cardiovascular and respiratory systems, the cortisol output in blood and saliva, and the degree of sedation and analgesia of 20 volunteers. A psychologic screening inventory was also performed. We found nitrous oxide, at low dosage, to be primarily an anxiolytic and not an analgesic or amnesic agent.