In vivo Microbiological Evaluation of Adhesive Systems After Stepwise Excavation

Objective: The purpose of this study was to assess the antimicrobial effect of two self-etching adhesives after stepwise excavation in vivo. Methods: After evaluation of specific clinical criteria, 44 children presented caries lesions and 47 primary molars were selected. Treatment consisted of incomplete excavation with burs in low speed, followed by the first collect of carious dentine in RTF (reduced transport fluid) solution, application of one of the self-etching adhesives: Clearfil SE Bond (Kuraray, Japan) – SE group (n=21) or Clearfil Protect Bond (Kuraray, Japan) containing MDPB antimicrobial agent – PB group (n=26) and sealing for 3 months. After this period, the temporary sealing was removed and second collect of remaining carious dentin was performed, following for the definitive sealing of the cavity. Microbiological samples (first and second collects) were serially diluted and cultivated in specific media for mutans streptococci – MS (Mitis salivarius agar), lactobacilli – LB (Rogosa agar) and total microorganisms – TM (Brain heart infusion agar supplemented with sheep blood) at 37^o C for 48h in anaerobic jars. Statistical analyses were conducted using Wilcoxon and Mann-Whitney tests. Results: MS, LB and TM counts were compared in the first collect of carious dentin and there was not significantly different (p>0.05) among groups, showing similar initial counts. Regardless adhesive system, there was decrease on LB and TM counts between first and second collects. However, PB showed antibacterial effect for MS. Conclusion: The antibacterial effect of the adhesive system is dependent microorganism. Supported by Fapesp 07/08544-9 and 08/05228-1.