Microbial Analysis of the Autogenous Bone Collected By Bone Filter

Objectives: The purposes of the presented study are 1) to identify the microbial content of the collected bone debris 2) to determinate the antibacterial efficiency of chlorhexidine mouthrinse in reducing the microbial content of the collected bone debris. Methods: Twenty five patients who had asymptomatic fully impacted mandibular third molars bilaterally underwent surgical removal for prophylactic and orthodontic considerations. Immediately prior to surgery, all patients rinsed with 10 ml of their assigned solution (chlorhexidine or sterile saline) for two minutes. Before the surgical removal of the teeth, bone debris was collected with a stringent aspiration protocol from the ramus by bone filter. The microbial content of the bone debris was assessed and the bacterial levels between two groups were compared statistically. Results: All samples from both groups (CH and SS) yielded viable microorganisms. There was no significant difference between the mean/median CFU/g values of both group samples, for aerobes (Streptococcus salivarius) and anaerobes (Bacteriodes, Peptococcus, Peptostreptococcus, and Veillonella species). With regards to total microorganisms, the mean CFU/g derived from Group CH samples were 1.5 x 108 CFU/g per bone sample compared to 1.5×109 CFU/g for control Group SS, P<0.05. Conclusion: Although chlorhexidine rinsing immediately prior to surgery reduced the levels of total microorganisms when compared with utilizing stringent aspiration protocol alone, it has not been found effective on aerobic Streptococcus salivarius and importantly on anaerobes. The reduced bacterial levels may still carry high infectious risk and may lead to failure in autogenous grafting procedures in oral surgery.