The purpose of this study was to evaluate the presence of dentinal defects after root canal preparation with hand instruments and two different reciprocating instruments. Sixty freshly extracted mandibular incisor teeth were selected for this in vitro study. On the basis of root length, mesiodistal and buccolingual dimensions, the teeth were allocated into three identical experimental groups (n...

What ever happened to the small-schools craze? A little over a decade ago, philanthropists and policy leaders, believing they had identified the key to student performance, threw their collective weight behind an effort to redesign the nation's large high schools. They spent over a billion dollars and transformed hundreds of large schools into smaller ones. Then, as suddenly as it began, the ef...

• Why did Europeans begin to amass overseas empires during the sixteenth century, and what effects did this experience have on both the Europeans and conquered peoples? • What role did religion play in the European wars of the sixteenth century and the Thirty Years’ War of the seventeenth century? • How did the religious policy, the foreign policy, and the governments of Philip II of Spain and ...

INTRODUCTION The purpose of this study was to evaluate the incidence of dentinal defects after root canal preparation with reciprocating instruments (Reciproc and WaveOne) and rotary instruments. METHODS One hundred human central mandibular incisors were randomly assigned to 5 groups (n = 20 teeth per group). The root canals were instrumented by using the reciprocating single-file systems Rec...