Incidence and magnitude of bacteraemia caused by flossing and by scaling and root planing

(1) Investigate incidence, magnitude and bacterial diversity of bacteraemia due to flossing compared with scaling and root planing (SRP) and (2) Identify any associations with clinical parameters.

Full-mouth flossing and single quadrant SRP were performed at separate visits for 30 patients with chronic periodontitis. Baseline blood samples and at 30 s and 10 min. after completion of flossing, 5 min. after initiation of SRP and 30 s and 10 min. after completion of SRP were obtained. Total bacteraemia and viridans streptococcal bacteraemia (VSB) were investigated.

Total bacteraemia incidence was 30% for flossing and 43.3% for SRP (no significant difference; p = 0.21). Flossing and SRP caused the same incidence of VSB (26.7%). Flossing caused a higher mean magnitude of total bacteraemia than SRP (7.4 ± 16.2 CFU/ml versus 2 ± 3.4 CFU/ml), but the difference was not significant (p = 0.2). Flossing caused a higher mean magnitude of VSB than SRP (1.2 ± 1.6 CFU/ml versus 0.4 ± 0.2 CFU/ml), but the difference was not significant (p = 0.09). Viridans streptococci comprised 11.4% of flossing bacteraemia isolates and 7.6% in SRP. No correlations were found between clinical parameters and incidence or magnitude of bacteraemia following flossing. Gingival inflammation was significantly associated with incidence of total bacteraemia (p = 0.01) and VSB (p = 0.001) following SRP. No correlations were found for any parameter and magnitude of total bacteraemia or VSB following SRP.

No differences were found between flossing and SRP in the incidence or magnitude of total bacteraemia or VSB. This finding is important in the ongoing re-evaluation of antibiotic prophylaxis to prevent infective endocarditis.