The reaction of dental pulp to Escherichia coli lipopolysaccharide and Enterococcus faecalis lipoteichoic acid

This research evaluates the effects of the lipopolysaccharides (LPS) from Escherichia coli and lipoteichoic acid (LTA) from Enterococcus faecalis on dental pulp. These molecules are components of the Gram-negative and Gram-positive bacteria cell wall, respectively. Ten dogs were used in the experiment. Inoculation in surgically opened pulp and coronal restoration with glass ionomer was the method chosen. The evaluation times were 1, 7, 15, 30 and 60 days. The results showed that the LPS and LTA, at 150 icg/ml, produced a negative interference in the pulp leading to destruction. LTA caused less damage than LPS.

Spectrophotometric and spectrofluorometric titrations of teichoic acid.

Spectrophotometric and spectrofluorometric titrations of two strongly aggregating dyes, 1,9-dimethylmethylene blue (DMMB) and acridine orange (AO), by three anionic biopolymers, chondroitin sulphate A, DNA and teichoic acid (TA), have been described. Though the three polymers differ in their dye binding efficiencies and TA is a weak chromotrope, the equivalent weights of the polymers can be estimated accurately by these methods using the two dyes. Results show DMMB to be the preferred dye for spectrophotometric titration. The titrations can be used to estimate the equivalent weights of anionic polymers, and also for the quantitative estimation of such polymers of known equivalent weights.