RESUMO
Aim: The aim of this in vitro study was to determine whether the addition of chlorhexidine (CHX)to a mouthwash containing fluoride (F) diminishes the concentration of soluble F and its reactivity withbovine dental enamel. Materials and Methods: First, the concentration of F found in mouthwashs wasdetermined by an ion-specific electrode. To test their reactivity, 30 slabs of bovine dental enamel (5 x 5mm)were distributed into three groups (n = 10), according to the treatment applied, for 30 seconds: controlgroup (distilled deionized water); NaF group (0.05% sodium fluoride); NaF + CHX group (Noplak Max®:0.05% sodium fluoride + 0.12% chlorhexidine digluconate). After, the slabs were washed with distilleddeionized water and individually immersed in artificial saliva for 30 minutes. They were dried and thenindividually immersed in 0.5 mL of 1M KOH for 24 hours, under agitation. After buffering the samples withHCI containing TISAB II, the concentration of F present in the KOH solutions was determined be means ofan ion-specific electrode. Results: No significant difference in the concentration of soluble F in the studiedmouthwashs (NaF and NaF+CHX; Students t-test, p > 0.05) could be observed. Furthermore, no differencecould be identified among the alkali soluble fluoride deposits from the NaF and NaF+CHX groups, andboth groups presented higher deposit levels than did the control group (Kruskal-Wallis and Dunn´s method,p < 0.05). Conclusion: The addition of CHX to a mouthwash containing F did not decrease its soluble Fconcentration, nor its reactivity to bovine dental enamel.