Premium
Bactericidal Action of Bicarbonate Ion on Selected Periodontal Pathogenic Microorganisms
Author(s) -
Newbrun Ernest,
Hoover Charles I.,
Ryder Mark I.
Publication year - 1984
Publication title -
journal of periodontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.036
H-Index - 156
eISSN - 1943-3670
pISSN - 0022-3492
DOI - 10.1902/jop.1984.55.11.658
Subject(s) - antimicrobial , microbiology and biotechnology , chemistry , bicarbonate , sodium bicarbonate , bacteria , biology , genetics , organic chemistry
O rganisms representative of soil, skin and fecal flora and of supragingival and subgingival flora were tested for inhibition of growth and killing by various salts (NaHCO 3 , NaCl, MgSO 4 ). The antimicrobial activities of KHCO 3 , NaF, sodium lauryl sulfate (SLS) and chloramine T were also compared with that of NaHCO 3 , and the rate at which NaHCO 3 exerts its bactericidal effect was studied. Suspected periodontal pathogens were more susceptible to salts than were control non‐oral bacteria. Supragingival plaque organisms showed intermediate susceptibility. Periodontal pathogens were more susceptible to NaHCO 3 than to NaCl; NaHCO 3 and KHCO 3 showed similar activity against all strains tested. Accordingly, the antibacterial activity of NaHCO 3 is not simply an osmotic effect and is due to the bicarbonate ion. NaF, SLS and chloramine T had greater antimicrobial activity than NaHCO 3 . Supragingival bacteria required at least 6‐hour exposure to 1.0 m NaHCO 3 to produce 99% lethality (decrease colony‐forming units by 2 log 10 ), whereas selected periodontal pathogens were killed more rapidly (30–120 minutes). The higher the concentration of bicarbonate, the faster the lethality. Morphologic examination by transmission electron microscopy of organisms exposed to bactericidal salt concentrations revealed marked fibrillar condensations within the cytoplasm and shrinkage of the cytoplasm from the outer membrane. For NaHCO 3 to be clinically effective, a high concentration must be introduced into the periodontal pocket and maintained there long enough to kill periodontal pathogens. Furthermore, NaHCO 3 must be reapplied often enough to prevent recolonization by these pathogens. An advantage of NaHCO 3 over NaF, SLS and other antimicrobial agents is its safety, availability and low cost.