Objective: Type I collagen is the main component of the organic matrix of dentin. The aim of this study was to compare the relative ease by which
E. faecalis may adhere to type I collagen treated by the various disinfectants used in root canal treatment, including calcium hydroxide (CH), ethylenediaminetetraacetic acid (EDTA), chlorhexidine (CHX) and sodium hypochlorite (NaOCl).
Methods: Type I collagen coated 96 well plates were treated with various chemicals (saline, saturated solution of CH, 17% EDTA, 2% CHX, 1.05 and 5.25 % NaOCl) and rinsed off with distilled water. Overnight culture of
E. faecalis was pipetted into each well and incubated for one hour. Assessment of the number of bacteria adhering was by a photometric assay. “OD values” representing the “the number of adherent bacteria” measured using a spectrophotometer reading at 650nm were analyzed by ANOVA.
Results: OD value (0.068±0.008) in CH treated group was statistically significantly more than all other groups (all
p<0.05), meaning that more bacteria adhered to type I collagen which had prior CH treatment. OD value (0.060±0.007) of 17% EDTA treatment group was statistically higher than CHX and NaOCl treated group (all
p<0.05), but similar to control (
p>0.05). There was no statistical difference between OD values in type I collagen treated with 2% CHX, 1.05 % and 5.25% NaOCl, which were 0.043±0.02, 0.040±0.002, 0.039±0.002, respectively (all
p>0.05).
Conclusions: The use of calcium hydroxide increases the adherence of bacteria, whereas chlorhexidine and sodium hypochlorite reduces the adhesion of bacteria on type I collagen. Acknowledgements: The study was supported by Guangdong Natural Science Foundation (S2012040007774), Fundamental Research Funds for the Central Universities (11ykpy46) and Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2013-693).