ADHERENCE OF STREPTOCOCCUS-GORDONII TO SMEARED AND NONSMEARED DENTIN

The purpose of this study was to investigate the adherence of Streptoc occus gordonii to smeared and nonsmeared dentine and to assess the inf luence of patent dentinal tubules on bacterial retention, In order to examine bacterial adherence, 10 non-smeared (group 1) and 10 smeared s amples (group 2) of outer root dentine were prepared from teeth exhibi ting dentine sclerosis, Ten non-smeared samples from inner coronal roo t dentine that did not exhibit sclerosis were prepared in order to stu dy the influence of patent tubules on bacterial retention (group 3), C ells of the bacterium were radioactively labelled and an adhesion assa y was performed, The number of bacteria adhering to the dentine surfac e was determined by scintillation counting, The results show that the number of bacteria adhering to both smeared acid non-smeared outer scl erotic dentine was low (0.3% of inoculum), and there was no significan t difference between the groups (P > 0.3), A significantly higher numb er of bacteria was retained on the inner non-smeared coronal root dent ine (P < 0.0001) compared to groups 1 or 2. The results suggest that d entinal smear layers do not enhance or impede bacterial adherence to t he dentine matrix, Dentinal surfaces with patent dentinal tubules reta in more bacteria than a smeared surface.