Five RCTs (312 patients analysed) and one CCT (24 patients analysed) were included in the review. Three RCTs were crossover double-blind, two RCTs were parallel double-blind and the CCT was parallel single-blind. Follow-up ranged from four days to six weeks. Two RCTs were considered low risk of bias, two moderate and one high risk of bias. The CCT was considered to be at high risk of bias.
Plaque (six trials): Two trials (one moderate and one high risk of bias) showed that hexetidine statistically significantly reduced plaque in the short term (<4 weeks) compared to placebo or saline but was less effective or of equal effectiveness when compared to chlorhexidine mouthwash.
Two trials that reported long-term effects (≥4 weeks) showed conflicting results when comparing the effectiveness of hexetidine versus placebo on plaque. One trial was at moderate and one at low risk of bias. The trial at low risk of bias compared the effects of hexetidine versus chlorhexidine on plaque accumulation and reported no statistically significant differences.
Other outcomes (two trials; one moderate and one low risk of bias): The two trials that assessed gingivitis and bleeding showed no statistically significant differences between treatments in the long term.
Higher concentrations of hexetidine resulted in more adverse effects compared to lower concentrations. Other results on adverse effects were reported in the review.