Aim: The aim was to clinically evaluate the antibacterial efficacy of two materials used as irrigants and intracanal medications (chlorohexidine, propolis) in secondary infection cases.
Materials and methods: Thirty-two patients with single-rooted, single-canal teeth associated with secondary infection were randomly assigned into four groups according to the type of irrigating and intracanal medication used. Group 1 (2% CHX irrigation and CHX gel intracanal medication), Group 2 (2% CHX irrigation and Propolis gel intracanal medication), Group 3 (30% Propolis irrigation and CHX gel intracanal medication), and Group 4 (30% Propolis irrigation and Propolis gel intracanal medication). The first microbial sample (S1) was obtained following complete aseptic removal of the primary filling then the second sample (S2) was obtained following chemomechanical preparation with various irrigant. ProTaper Universal rotary system was used up to F4, or F5 for root canal reinstrumentation. Finally, the third microbial sample (S3) was collected after removal of the intracanal medication. After cultivating the three samples, the growing colonies were counted and recorded as colony forming units (CFU).
Results: The third sample after intracanal medication recorded the lowest microbial count in all groups. No statistical significant difference was recorded between the rate of reduction of S2 to S1 among the tested groups while there was statistically significant difference in microbial reduction of S3 to S2. Comparing between groups regardless the samples, there was no statistical significant differences between the groups.
Conclusions: Both CHX and Propolis irrigation and intracanal medication aid in microbial reduction, particularly in cases of secondary infection.