Models based on the crystal structure of interleukin-1 vary significantly. D eP ri st o/ El se vi er UK) warns that, for any given structure in the Protein Data Bank (PDB), there will be many other overlooked structures that are equally consistent with the data. Crystallized proteins retain the ability to move around, thus making interpretations of diffraction data an imprecise process. Crystal...

i ntroduction: apical debris extrusion (de) subsequent to root canal instrumentation, is one of the most important causes of endodontic flare-ups. the aim of this study was to compare the amount of de after root canal instrumentation using nickel-titanium (niti) hand files with step-back manual technique or installed on reciprocating handpiece. methods and materials: this study was conducted on...