Radiographic and histologic evaluation of the effect of endotoxin on the periapical tissues of the cat.

T h e pe r iap ica l t issue reac t ion to th ree concen t r a t i ons of Escherichia coli e n d o t o x i n solut ions , to th ree de toxi f ied E coli e n d o t o x i n solut ions , and to a steri le saline cont ro l so lu t ion was e x a m i n e d in ten adul t cats. T h e max i l l a ry and m a n d i b u l a r canines were i so la ted wi th a r u b b e r d a m , and the pu lp s we re ext i rpa ted . T h e so lu t ions were depos i t ed in the root canals of each cat, and the access cavit ies were sealed. T h e per iapica l t i ssues we re e x a m i n e d h is to log ica l ly and r ad iograph ica l ly at 2, 4, a n d 6 weeks . T h e r ad iog raph ic and his to logic resul ts ind i rec t ly sugges t tha t e n d o t o x i n s have a pa r t in ini t iat ing and p e r p e t u a t i n g per iap ica l i n f l a m m a t o r y les ions in man .