IN-VITRO ATTACHMENT OF STREPTOCOCCUS-SANGUIS TO THE DENTIN OF THE ROOT-CANAL

The adhesion of a strain of Streptococcus sanguis (NCTC 7863) to the r oot canal dentin of bovine incisors was evaluated. Samples (104) were prepared and smear layer was created on the root canal surface with a tungsten carbide bur. The samples were divided into four groups, one o f them serving as a control sample and the other three each receiving a different treatment: 6% citric acid for 2 min (group 3), 6% citric a cid for 2 min + 6.25% sodium hypochlorite for 1 min (group 2), 6% citr ic acid for 10 min (group 4). After sterilization, they were incubated , and adhesion was assessed by direct examination using a scanning ele ctron microscope. The use of irrigation solutions significantly reduce d the adhesion in the latter two groups only, with a reduction of 15% (group 2) and 18.7% (group 4) in the number of bacteria.