Effect of Chlorhexidine Varnish on Streptococci in Dental Plaque from Occlusal Fissures

Abstract

The treatment of tooth surfaces with chlorhexidine varnish may lead to long-lasting suppression of mutans streptococci in dental plaque. Microbiological observations following varnish treatment suggest that this prolonged suppression might be caused by bacterial interference. To investigate whether physiologically related organisms, such as other Streptococcus species, compete with mutans streptococci in the ecosystem, we have analyzed streptococcal populations on the tooth surface before and after chlorhexidine varnish treatment. Occlusal surfaces with high numbers of mutans streptococci were selected in human volunteers and treated with chlorhexidine varnish. Analyses of sequentially collected plaque samples confirmed that S. oralis-group streptococci returned to baseline levels shortly after the chlorhexidine application, while Actinomyces naeslundii populations reached prestudy or even higher levels only several days after treatment. Mutans streptococci, however, were below the detection level in the 14-day samples, except in 1 individual. The pattern of recolonization by individual Streptococcus species after chlorhexidine application closely resembled that of cleaned enamel surfaces: S. oralis and S. sanguis were primary colonizers while S. gordonii became dominant at a later stage. It is concluded that after intensive chlorhexidine treatment, a normal oral microflora reestablished, characterized by low proportions of mutans streptococci.

The Effect of 6-Monthly Application of 40% Chlorhexidine Varnish on the Microflora and Dental Caries Incidence in a Population of Children in Surinam

“…A consistent finding in several studies is an initial drop and quick recovery in numbers of Actinomyces naeslundii and streptococci of the mitis group (previously called oralis group) after a CHX varnish application, while MS remain decreased in numbers for a longer period of time [Schaeken and De Haan, 1989;Schaeken et al, 1994]. This is probably due to the reported sensitivity of MS compared to other streptococci.…”

“…Furthermore, most effects of CHX on salivary MS have been seen within a period of 2-3 months, while a longer effect was observed in plaque [Schaeken et al, 1994]. In the present study, data were obtained on a 6-monthly interval basis.…”

Influence of Repeated Chlorhexidine Varnish Applications on Mutans Streptococci Counts and Caries Increment in Patients Treated with Fixed Orthodontic Appliances

“…For suppression of mutans streptococci a commercially available 40% chlorhexidine varnish based on Sandarac resin was used [9][10][11] (EC-40; explore Biodent B. V., Arnheim, The Netherlands). After thorough drying and placing of cotton rolls, all tooth surfaces and orthodontic appliances were coated with the varnish, using a dental syringe.…”

“…The suitability of EC-40 varnish for long-term suppression of elevated mutans streptococci levels has been documented in various clinical studies [9][10][11]. Clinical practice, however, shows that the duration of mutans streptococci suppression depends in part on the extent to which any retention niches are coated with varnish [14].…”

“…Die Eignung des verwendeten EC-40-Lackes zur langfristigen Absenkung hoher Mutans-Streptokokken-Werte wurde durch diverse klinische Studien dokumentiert [9][10][11]. Die klinische Praxis zeigt jedoch, dass die Dauer der Mutans-Streptokokken-Supprimierung nicht zuletzt davon abhängt, inwieweit es gelingt, alle möglichen Retentionsnischen während der Lackapplikation zu erfassen [14].…”