A randomized controlled cross-over study of the effect of alcohol-free chlorhexidine and essential oils on interleukin-1 levels in crevicular fluid.

Aim of the study was to determine the effect of an alcohol-free chlorhexidine mouth rinse and an essential oils containing mouth rinse on pro-inflammatory cytokine levels in gingival crevicularfluid in participants who continue to perform their regular mechanical oral hygiene regimes and normal dietary practice. Twenty adult volunteers (mean age: 59 years) participated in the double-blind randomised controlled cross-over study.Three mouth rinses were used during 16-day periods as an adjunctiveto regular mechanical oral hygiene: a solution with alcohol-free chlorhexidine (CHX; Paroex), a solution with essential oils (EO; Listerine), and water (negative control).The mouth rinse periods were separated by 3-month washout periods. At days o (baseline) and 17 (end) of each mouth rinse period, gingival crevicular fluid (GCF) was collected at different tooth sites and analyzed with ELISA technique for IL-1α, IL-1β and IL-ira levels. No significant correlations between clinical parameters (QHI and GI) and cytokine concentra- tions were observed, regardless of mouth rinse regimen.The generalized linear models revealed that none of the mouth rinses had a statistically significant impact on IL-1 concentrations in GCF. Large inter-individual variations were observed for the levels of IL-iα, IL-1β and IL-ira. Also the changes in concentrations between day o and day 17fo r the mouthrinses showed large intra-individual variations. It can be concluded that neither the alcohol-free chlorhexidine nor the mouth rinse contain- ing essential oils reduced the levels of IL-iα, IL1β and IL-ira in GCF.