E. Giertsen et Aa. Scheie, EFFECTS OF CHLORHEXIDINE-FLUORIDE MOUTHRINSES ON VIABILITY, ACIDOGENIC POTENTIAL, AND GLYCOLYTIC PROFILE OF ESTABLISHED DENTAL PLAQUE, Caries research, 29(3), 1995, pp. 181-187
Inhibition of dental plaque acidogenicity by chlorhexidine (CHX) mouth
rinses has been ascribed to a long-lasting bacteriostatic effect due t
o binding of CHX to oral surface structures combined with a slow relea
se rate from the binding sites. The present aims were to study the eff
ects of CHX-containing mouthrinses on the viability and glycolytic act
ivity of established plaque in order to assess the bactericidal versus
the bacteriostatic effects. Following 2 days of plaque accumulation,
three groups of 10 students rinsed with either 12.0 mM NaF, 0.55 mM CH
X plus NaF, or with 2.2 mM CHX plus NaF. Plaque samples were collected
before and 90 min after mouthrinsing. The pH in pooled pre- and post-
rinse plaque samples was recorded before and up to 10 min after the ad
dition of D-[U-C-14]glucose. Total colony-forming units in each sample
were determined. High-performance liquid chromatography analyses show
ed lactate to be the major extracellular glycolytic metabolite in all
samples. CHX-NaF markedly reduced the colony-forming units, the pH fal
l from fermentation of glucose, as well as glucose consumption and lac
tate formation, whereas NaF alone exhibited no such effects. The reduc
tion of glucose consumption by the CHX-NaF mouthrinses corresponded to
the reduction of colony-forming units, indicating no bacteriostatic e
ffect. The plaque pH in vivo was monitored in each student 90 min afte
r mouthrinsing with the test solutions prior to and up to Ih after a s
ucrose mouthrinse using touch microelectrodes. The CHX-NaF mouthrinses
reduced the fall in pH significantly (p < 0.05) as compared with the
NaF mouthrinse. The results suggested that the reduced acid formation
by dental plaque following a CHX mouthrinse is due to a bactericidal e
ffect rather than a long-lasting bacteriostatic action.